WO2020261605A1 - Structure de fixation de rondelle - Google Patents

Structure de fixation de rondelle Download PDF

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Publication number
WO2020261605A1
WO2020261605A1 PCT/JP2019/049481 JP2019049481W WO2020261605A1 WO 2020261605 A1 WO2020261605 A1 WO 2020261605A1 JP 2019049481 W JP2019049481 W JP 2019049481W WO 2020261605 A1 WO2020261605 A1 WO 2020261605A1
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WO
WIPO (PCT)
Prior art keywords
washer
stress
bolt hole
transmission space
nut
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Application number
PCT/JP2019/049481
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English (en)
Japanese (ja)
Inventor
松尾　誠
興明 林田
喜直 岩本
Original Assignee
株式会社松尾工業所
株式会社iMott
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 株式会社松尾工業所, 株式会社iMott filed Critical 株式会社松尾工業所
Priority to CN201980097693.1A priority Critical patent/CN114008335B/zh
Priority to JP2021527326A priority patent/JP7128500B2/ja
Publication of WO2020261605A1 publication Critical patent/WO2020261605A1/fr

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B31/00—Screwed connections specially modified in view of tensile load; Break-bolts
    • F16B31/06—Screwed connections specially modified in view of tensile load; Break-bolts having regard to possibility of fatigue rupture
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B43/00—Washers or equivalent devices; Other devices for supporting bolt-heads or nuts

Definitions

  • the present invention relates to an improvement of a washer used in a properly tightened bolt / nut fastener, and reduces the load sharing ratio of the first mesh thread that maximizes the thread load sharing ratio of the bolt. It relates to a washer and a manufacturing method thereof for improving the breaking strength of fatigue cracks from the bottom of the valley.
  • the improvement of the washer of the present invention not only reduces the load sharing rate of the first thread of meshing of the bolt, but also has an effect of leveling the load sharing rate of each thread, and the fatigue breaking strength from the threaded portion of the bolt. Can be enhanced.
  • Bolts, nuts and washers are used to fasten various structures. It is used in all kinds of equipment such as automobiles, ships, construction, railroad vehicles, civil engineering machines, and various machine tools. Fatigue fracture starting from the bottom of the bolt thread valley (Fig. 4, * part of the bolt) at the first meshing thread is often a problem with this fastening member, and efforts have been focused on improving the strength of the bolt as a countermeasure against fatigue fracture. Excessive load due to the static fastening force and external force of the first meshing thread is known, but the structure of the washer was examined for the purpose of improving the fatigue strength of the bottom of the bolt screw valley of the first meshing thread. It hasn't been done.
  • FIG. 1 is a vertical cross-sectional view showing fastening of objects to be fastened with conventional bolts, nuts, and washers.
  • 1 is a washer
  • 2 is an object to be fastened
  • 3 is a bolt
  • 4 is a nut
  • 5 is a base
  • 4o is the open side of the nut thread (the direction of the arrow is the direction in which the screw is loosened)
  • 4c is the fastening side of the nut thread ( The direction of the arrow indicates the direction in which the screw is tightened).
  • the numerical value of the load sharing ratio for flange nuts with 7 threads verified by the present inventor by finite element analysis (FEM analysis) is 35.6% for the first thread.
  • the 2nd mountain is 20.8%
  • the 3rd mountain is 14.4%
  • the 4th mountain is 11.0%
  • the 5th mountain is 8.6%
  • the 6th mountain is 5.9%
  • the 7th mountain is 3 It was also confirmed that the load sharing decreased sharply toward the open side of the screw thread at 9.9% (see FIGS. 4 and 9), which is consistent with many reports.
  • Non-Patent Document 1 There are standards such as JIS and ISO for washers, and the main regulations are size (dimensions), hardness, parallelism, and geometric tolerance. Regarding the shape, the ring has a rectangular cross section, and part of the outermost surface is chamfered diagonally. There are only some that have been made (Non-Patent Document 1).
  • the conventional washer has not been expected to have a function of improving the flow of force entering the nut or bolt in the required function. There was only a demand for functions such as the nut bearing surface not sinking into the object to be fastened and the surface texture of the object to be fastened not affecting the rotation of the nut.
  • Patent Document 1 discloses a set of high-strength bolts, nuts, and washers that reduce stress concentration generated at the bottom of the thread at the meshing end and have excellent delay fracture resistance and fatigue resistance.
  • a protruding portion is provided on the center side of the diameter of the nut, and the washer has a height so that the protruding portion does not come into contact with the object to be fastened at a steady state.
  • An example of a straight notch is shown for the central corner in contact with the nut of the washer.
  • Patent Document 1 is characterized by a special nut having a protruding portion on the center side of the diameter, and the washer is a set part that complements the special nut, and the washer alone is not useful.
  • the inner peripheral surface of the washer of Patent Document 1 does not align (center) the shaft of the bolt.
  • the force flow on the nut side is most concentrated on the first thread for meshing with respect to the force in the bolt axial direction (initial tightening axial force: average stress, axial external force: fluctuating stress). It shows a non-uniform force flow characteristic that drops sharply after the second thread.
  • the force flow between the object to be fastened, the washer, and the nut is arranged as wide as possible on the outer peripheral side of the nut so that the force flow is widely distributed on each meshing thread and the first meshing screw. It has the effect of reducing the load concentration on the mountain. It provides a washer fastening structure that realizes this effect.
  • the washer fastening structure is optimized, and the inflow position of the force entering the nut is guided to the outer peripheral side of the nut bearing surface, so that a large amount of force is directed to the open side of the nut, and as a result, the bolt and the nut are fastened and meshed. It relates to the object of reducing the load on the first mountain, and the following aspects of the invention are provided.
  • a bolt (3) extending from the object to be fastened (2) is inserted into a bolt hole (1h) of the object to be fastened (2) and a washer (1), and the washer (1) is inserted into the bolt (3) and the nut (4).
  • the bolt (3), the washer (1), the nut (4), and the washer fastening structure have a common axis and axis direction (hereinafter, also simply referred to as "the axis” and “the axis direction”) and the axis.
  • has a radial direction perpendicular to hereinafter, also simply referred to as "the radial direction").
  • the washer (1) has a washer body (1b) and a bolt hole (1h) penetrating the washer body (1b).
  • the washer body (1b) has a stress non-transmission space (1s) that is a concentric annular shape centered on the axis of the bolt hole (1h).
  • the direction from the object to be fastened (2) to the washer (1) and from the washer (1) to the nut (4) is upward, upward or upward, and the opposite direction is downward, downward or downward.
  • the nut (4) has a flat lower plane (4w) extending in the radial direction and a screw extending in the axial direction, and the screw is alternately composed of threads and threads, and is a screw.
  • the stress non-transmission space (1s) of the washer body (1b) is formed from the inner peripheral surface (1i) of the bolt hole of the washer body (1b) in a vertical cross section including the axis of the washer (1).
  • the distance Ls in the radial direction from the position Ps to the extension line (4e) of the line connecting the screw valley bottoms of the nut (4) is the said distance Ls of the nut (4), where Ps is the position farthest to the outside in the radial direction.
  • the washer body (1b) has a flat upper plane (1u) extending in the radial direction on the nut (4) side and a flat lower surface (1u) extending in the radial direction on the object to be fastened (2) side. It has a flat surface (1w) and a bolt hole inner peripheral surface (1i) parallel to the axis line defining the bolt hole (1h).
  • the washer (1) has a thickness (T) from the upper plane (1u) to the lower plane (1w).
  • the stress non-transmission space (1s) is a first stress non-transmission space (11s) that opens in the bolt hole (1h) and also in the upper plane (1u) of the washer body (1b).
  • the first stress non-transmission space (11s) is formed in a vertical cross section including the axis of the washer (1).
  • the extension line of the upper plane (1u) of the washer body (1b) is defined as the first boundary line (B1)
  • the extension line of the inner peripheral surface of the bolt hole (1i) is defined as the second boundary line (B2).
  • the position where the first boundary line (B1) intersects the second boundary line (B2) is Po, and the distance Lh in the axial direction from the position Ph to the position Ph is the screw of the nut (4). It is in the range of 0.01 times or more of the pitch p to 99% or less of the thickness (T) of the washer (1).
  • the first stress non-transmission space (11s) is a space surrounded by the first boundary line (B1), the second boundary line (B2), and the third boundary line (B3) in the vertical cross section.
  • the washer fastening structure having the first stress non-transmission space (11s) is referred to as "aspect A".
  • the drawings of this aspect A correspond to FIGS. 5 to 12.
  • the third boundary line (B3) of the first stress non-transmission space (11s) is at least deep in the axial direction from the first boundary line (B1).
  • the third boundary line (B3) of the first stress non-transmission space (11s) is a fastening force applied to the upper plane (1u) of the washer body (1b). Is applied to the washer (1) assuming that the upper plane (1u) of the washer (1) is flat from the position Pt to the position Po, and is generated in the washer of the assumption.
  • the bolt hole is more than the stress distribution line on the bolt hole (1h) side where the relative stress is 95% based on the magnitude of the stress equivalent to Mieses applied vertically downward from the position Pt.
  • the washer body (1b) has a flat upper plane (1u) extending in the radial direction on the nut (4) side and a flat lower surface (1u) extending in the radial direction on the object to be fastened (2) side. It has a flat surface (1w) and a bolt hole inner peripheral surface (1i) parallel to the axis line defining the bolt hole (1h).
  • the washer (1) has a thickness (T) from the upper plane (1u) to the lower plane (1w).
  • the stress non-transmission space (1s) of the washer body (1b) is a second stress non-transmission space (12s) that does not open in the upper plane (1u) of the washer body (1b).
  • the second stress non-transmission space (12s) is radially outside from the position P1 of the inner peripheral surface (1i) of the bolt hole of the washer body (1b) in the vertical cross section including the axis of the washer (1).
  • the line extending to the position Ph of the inner peripheral surface (1i) of the bolt hole or reaching the position P3 of the lower plane (1w) of the washer body (1b) is defined as the fourth boundary line (B4), and the bolt.
  • a space in which the extension line of the inner peripheral surface (1i) of the hole is the fifth boundary line (B5), or optionally, the extension line of the lower plane (1w) of the washer body (1b) is the sixth boundary line (B6).
  • the minimum thickness (Th) of the eaves which is the shortest dimension in the axial direction from the upper plane (1u) of the washer body (1b) to the second stress non-transmission space (12s), is the thickness of the washer 1. 1% or more of T,
  • the second stress non-transmission space (12s) is the fourth boundary line (B4) and the fifth boundary line (B5), or the fourth boundary line (B4) and the fifth boundary line (B4) in the vertical cross section.
  • the washer fastening structure having the second stress non-transmission space (12s) is referred to as "aspect B").
  • the washer fastening structure according to the second aspect is referred to as "aspect B").
  • the second stress non-transmission space (12s) is also opened on the lower plane (1w) side of the washer body (1b), and the fourth boundary line (B4).
  • ) Extends upward from the lower plane (1w) of the washer body (1b) at an angle within 20 degrees with respect to the axis direction, and is in contact with a straight line forming an elevation angle of 20 to 25 degrees with respect to the axis.
  • a corner portion (Bc) connecting the rising portion (Br) leading to the position and a position in contact with two straight lines forming elevation angles of 20 to 25 degrees and 65 to 70 degrees with respect to the axis, and the corner portion (Bc) connecting the corner portion to the above.
  • the washer fastening structure according to aspect 6, which includes a bolt hole inner peripheral end portion (Be) leading to the bolt hole inner peripheral surface (1i).
  • the fourth boundary line (B4) is a connection point of the washer body (1b) with the lower plane (1w) and / or the inner peripheral surface of the bolt hole (1i).
  • the washer body (1b) has a stress non-transmission space (1s) that opens into the bolt hole (1h) and extends in the radial direction in a vertical cross section including the axis of the washer (1).
  • a washer characterized in that the stress non-transmission space (1s) is a concentric annular shape centered on the axis of the bolt hole (1h).
  • the stress non-transmission space (1s) of the washer body (1b) is in the radial direction from the inner peripheral surface (1i) of the bolt hole of the washer body (1b) in the vertical cross section of the washer (1).
  • Ps be the position of the stress non-transmission space (1s) farthest to the outside, and the distance L in the radial direction from the position Ps to the inner peripheral surface parallel to the axis of the bolt hole (1h) or an extension line thereof.
  • 0.5p ⁇ L ⁇ 5.7p In the formula, the diameter of the bolt hole (1h) is R, and the units of R and p are mm.
  • R When R is 1.9 or less, p is 0.2 and When R is more than 1.9 and less than 2.4, p is 0.25. When R is more than 2.4 and 3.7 or less, p is 0.35. When R is more than 3.7 and 5.5 or less, p is 0.5. When R is more than 5.5 and 7.5 or less, p is 0.75. When R is more than 7.5 and 9.5 or less, p is 1.0. When R is more than 9.5 and 13 or less, p is 1.25. When R is more than 13 and 23 or less, p is 1.5. When R is more than 23 and less than 34, p is 2. When R is more than 34 and less than 40, p is 3. When R is more than 40 and 150 or less, p is 4. ) The washer according to aspect 12, which satisfies the above conditions.
  • the stress non-transmission space (1s) is a first stress non-transmission space (11s) that also opens to the first plane (1u) of the washer body (1b).
  • the washer body (1b) extends below the first stress non-transmission space (11s) to an inner peripheral surface of the bolt hole (1h) parallel to the axis.
  • the washer fastening structure having the first stress non-transmission space (11s) is referred to as "aspect A”.
  • the third boundary line (B3) between the washer body (1b) and the first stress non-transmission space (11s) is the first plane.
  • the stress concentration relaxation line is composed of a curved line or a combination of a curved line and a straight line, and has no corners.
  • the washer (1) of the aspect A in the vertical cross section of the washer (1).
  • the boundary line (B3) between the washer body (1b) and the first stress non-transmission space (11s) has a shape in which the washer body (1b) does not have the first stress non-transmission space (11s).
  • the upper plane (1u) is assumed to be. Is 95% of the stress value equivalent to Mieses, which is 95% of the stress value equivalent to Mieses applied in the downward direction perpendicular to the upper plane (1u) from the position where is in contact with the first stress non-transmission space (11s).
  • the third boundary line (B3) between the washer body (1b) and the first stress non-transmission space (11s) is a curved line or a straight line with a curved line, and is a stress concentration relaxation line having no corners.
  • the first plane (1u) of the washer body (1b) extends to the inner peripheral surface (1i) of the bolt hole parallel to the axis of the bolt hole (1h).
  • the washer body (1b) forms an eaves portion (1p) on the upper side of the first plane (1u), and the stress non-transmission space (1s) is formed on the lower side of the eaves portion (1p).
  • the existing second stress non-transmission space (12s) (Hereinafter, the washer fastening structure having the second stress non-transmission space (12s) is referred to as "aspect B").
  • the second stress non-transmission space (12s) is on the second plane (1w) side of the washer body (1b).
  • the boundary line (B4) between the washer body (1b) and the second stress non-transmission space (12s) is in the axial direction from the second plane (1w) of the washer body (1b).
  • the rising portion (Br) that extends upward at an angle within 20 degrees to reach a position where it comes into contact with a straight line forming an elevation angle of 25 degrees with respect to the axis, and elevation angles of 20 to 25 degrees and 65 with respect to the axis.
  • Aspect 17 includes a corner portion (Bc) connecting a straight line forming about 70 degrees and a position in contact with each other, and a bolt hole inner peripheral end portion (Be) extending from the corner portion to the bolt hole inner peripheral surface (1i). Described washer.
  • the fourth boundary line (B4) between the washer body (1b) and the second stress non-transmission space (12s) in the vertical cross section of the washer (1) of the aspect B. ) Is a curved line or a straight line with a curved line and has no corners, and is a stress concentration relaxation line. However, the connection portion with the second plane (1w) does not have to be a stress concentration relaxation line. Or the washer according to 18.
  • Aspect 12 in which a part or all of the surface of the washer (1) is subjected to surface treatment for the purpose of rust prevention, abrasion resistance, lubricity improvement, slidability improvement, appearance improvement, decoration, or identification.
  • the washer according to any one of 21 to 21.
  • Aspect 26 Aspects 12 to 25 characterized in that the washer (1) is processed and manufactured by pressing, cutting, grinding, cold, warm, hot pressing, casting, forging, or a combination of these methods. The method for manufacturing a washer according to any one of the items.
  • the load sharing ratio of the first thread of fastening mesh of bolts and nuts can be reduced, for example, from 35.6% of the conventional structure to around 30%. Due to this effect, the stress of the total actual load, which is repeatedly input in the direction of the initial fastening axial force, is also reduced at the same rate, so that the fatigue strength of the bolt thread valley bottom of the first meshing thread is improved. It has the effect of improving the safety and durability of the fastening structure.
  • the washer fastening structure of the present invention mainly improves the fatigue strength of a bolt screw, but it is known that a nut screw also deteriorates due to the same cause and mechanism as a bolt screw. Although the fatigue failure of bolts is less than that of bolts, the washer of the present invention is also effective in improving the fatigue strength of nut screws.
  • FIG. 1 is a vertical cross-sectional view showing an example of a fastening structure using a conventional washer.
  • FIG. 2 is a diagram showing a flow of tensile stress applied to a bolt in the fastening structure of FIG.
  • FIG. 3 is a diagram showing the flow of compressive stress applied to the nut in the fastening structure of FIG.
  • FIG. 4 is a diagram showing a Mises equivalent stress distribution in which the tensile stress of FIG. 2 and the compressive stress of FIG. 3 are combined.
  • FIG. 5 is a vertical cross-sectional view showing an example of a fastening structure using a washer according to the aspect A of the present invention.
  • FIG. 6 is a partially enlarged vertical sectional view of the washer fastening structure of FIG.
  • FIG. 7 (a) is a vertical cross-sectional view of the washer of FIG. 5, and FIGS. 7 (b) and 7 (c) are perspective views of the washer of FIG.
  • FIG. 8 is a diagram showing a Mises equivalent stress distribution in the example of the washer fastening structure of FIG. 9 (a) and 9 (b) are tables and graphs comparing the Mises equivalent stress distributions of FIGS. 4 and 8.
  • FIG. 10 is a graph and a diagram showing a Mises equivalent stress distribution when the shape of the first stress non-transmission space is changed in the example of the washer of the aspect A.
  • 11 (a) and 11 (b) are diagrams showing the Mises equivalent stress distribution and the shape of the first stress non-transmission space in the washer of the aspect A.
  • FIG. 12 (a) to 12 (e) are vertical cross-sectional views showing a modified example of the washer according to the aspect A of the present invention.
  • FIG. 13 is a vertical sectional view showing an example of a fastening structure using a washer according to the aspect B of the present invention.
  • FIG. 14 is a partially enlarged vertical sectional view of the vertical sectional view of the washer of FIG. 15 (a) is a vertical cross-sectional view of the washer of FIG. 13, and FIGS. 15 (b) and 15 (c) are perspective views of the washer of FIG.
  • FIG. 16 is a diagram showing a Mises equivalent stress distribution in the example of the washer fastening structure of FIG. 17 (a) and 17 (b) are tables and graphs comparing the Mises equivalent stress distributions of FIGS.
  • FIG. 18 is a graph and a diagram showing a Mises equivalent stress distribution when the shape of the second stress non-transmission space is changed in the example of the washer of the aspect B.
  • 19 (a) to 19 (d) are vertical cross-sectional views showing a modified example of the washer according to the aspect B of the present invention.
  • FIG. 20 is a vertical sectional view showing a modified example of the washer according to the aspect B of the present invention.
  • 21 (a) to 21 (d) show an example of the shape of the cutting tool for manufacturing the washer of the present invention.
  • FIG. 22 shows an example of a mold for manufacturing the washer of the present invention.
  • FIG. 23 shows an example of a mold such as a mold for manufacturing the washer of the present invention.
  • the present invention A bolt (3) extending from the object to be fastened (2) is inserted into a bolt hole (1h) of the object to be fastened (2) and a washer (1), and the washer (1) is inserted through the bolt (3) and the nut (4).
  • the bolt (3), the washer (1), the nut (4), and the washer fastening structure have a common axis and axis direction (hereinafter, also simply referred to as "the axis" and "the axis direction”) and the axis.
  • the washer (1) has a washer body (1b) and a bolt hole (1h) penetrating the washer body (1b).
  • the washer body (1b) has a stress non-transmission space (1s) that is a concentric annular shape centered on the axis of the bolt hole (1h).
  • the stress non-transmission space (1s) provides a washer fastening structure characterized in that it is open to the bolt hole (1h).
  • FIG. 1 is a vertical cross-sectional view showing an example of a washer fastening structure in the prior art
  • FIG. 5 is a vertical cross-sectional view showing an example of a washer fastening structure on the first side surface of the present invention.
  • a bolt (3) extending from the substrate 5 side is inserted into a bolt hole (1h) of the object to be fastened (2) and a washer (1), and a washer (1) is interposed.
  • the present invention relates to a washer fastening structure for fastening an object to be fastened (2) to a substrate (5) with bolts (3) and nuts (4).
  • the washer (1) exists between the nut (4) and the object to be fastened (2).
  • the bolt (3) penetrates the substrate (5), the object to be fastened (2) and the washer (1) and is connected to the nut (4), whereas the bolt (3) is It may be a part of the substrate (5), or it may be embedded in the substrate (5) and does not penetrate the substrate (5).
  • the bolt (3) has a columnar screw shaft body and a screw portion (male screw) that engages with a nut at the tip of the screw shaft body, and the screw portion has threads and threads, and between threads and threads. It has a pitch p, which is the distance between the valleys.
  • the outer diameter of the bolt (3) is usually designated by the diameter of the thread top.
  • the tip side having the threaded portion of the bolt (3) is called the (screw) opening side, and the opposite direction is called the (screw) fastening side.
  • the nut (4) also has an open side (4o) at which the screw of the nut is released and a fastening side (4c) at which the nut is fastened.
  • the nut (4) has a screw shaft portion (4s) and a female screw (thread portion) that penetrates the screw shaft portion (4s) and corresponds to the male screw of the bolt (3).
  • the thread diameter of a nut is usually referred to by the diameter of the thread root.
  • the cross section of the screw shaft portion (4s) is generally hexagonal, but it may be a polygon other than a hexagon.
  • the nut (4) is not essential, but preferably has a flange portion (4f) on the washer (1) side of the screw shaft portion (4s).
  • the flange portion (4f) refers to a portion having an outer peripheral dimension larger than the outer peripheral dimension of the screw shaft portion (4s).
  • the outer peripheral dimensions of the screw shaft portion (4s) and the flange portion (4f) may be the dimensions (diameter) of a circle inscribed in the screw shaft portion (4s) and the flange portion (4f) in the plan view.
  • the thread of the nut (4) has threads and threads and has the same pitch p as the thread of the bolt (3), but the diameter of the thread root of the nut (4) is slightly smaller than the outer diameter of the bolt (3). Is set to a large value.
  • the diameter of the thread crest of the nut (4) is set slightly larger than the diameter of the thread crest bottom of the bolt (3).
  • the open side of the bolt (3) is called the open side (4o) of the nut (4), and the opposite direction is called the fastening side (4c).
  • the object to be fastened (2) and the substrate (5) are not particularly limited. If the object to be fastened and the substrate are fastened with bolts and nuts, the benefits of the washer fastening structure of the present invention can be enjoyed. Fastening with bolts and nuts is widely used in aircraft, automobiles, railroad vehicles, machine tools, civil engineering machines, agricultural machines, various manufacturing equipment, bridges, building structures, etc., and the washer fastening structure of the present invention is any of them. Is also applicable.
  • the number of threads of a screw indicates the order of the threads counted from the first thread of fastening meshing. Since the screw is spiral in the axial direction, the position of the thread number of the screw is the position at the average value (median value).
  • FIG. 2 is a vector diagram showing the direction and magnitude of tensile stress applied to the bolt (3) when the bolt (3) and the nut (4) are fastened in a fastening body including a conventional washer by FEM analysis.
  • the direction of the vector in the figure is the direction of stress, and the length and density of the vector represent the magnitude of stress.
  • the tensile stress applied to the bolt (3) is maximum at the first thread of the fastening mesh and decreases toward the higher thread on the open side.
  • FIG. 3 shows FEM analysis of the direction and magnitude of the compressive tension applied to the nut (4) when the bolt (3) and the nut (4) are fastened in the fastening body including the conventional washer.
  • FIG. 4 is a FEM analysis of the Mises equivalent stress applied when fastening the bolt (3) and the flange nut (4) having the shape shown in FIG. 4 in the fastening body including the conventional washer. It is a diagram that combines the tensile stress diagram, the compressive stress of FIG. 3, and its reaction force.
  • the region where the Mises equivalent stress is maximum is white
  • the region where it is minimum is black
  • the middle is represented by two levels of light and dark gray (gray scale).
  • the force (white area) applied from the innermost diameter of the washer concentrates on the first thread on the fastening side of the nut immediately above, and the first thread of this nut is filled with white and light gray. It works in the direction of pressing the fastening side surface of the first thread of the bolt, and presses against each other in white, and white and light gray are also generated inside the bolt.
  • an axial force is applied to the bolt downward (toward the bolt head direction), and the force is exchanged with the nut at the thread on the open side from the first mesh thread.
  • the thread just below the first thread of the bolt screw receives a lot of bolt axial force because there is no nut thread, and the first thread of the nut works to push up the first thread of the bolt screw. It is under great stress to open the part.
  • it is transmitted to the second thread, and there are small white and light gray around, but it is much smaller than the first thread, and dark gray has entered the nut thread.
  • the light gray on the 3rd thread appears small on the nut thread side, the 4th thread becomes almost dark gray, and the 5th thread has a lot of weak black stress, and the 6th and 7th threads. In the eyes, black with low stress is the most distributed.
  • this stress distribution situation shows a non-uniform situation far from leveling.
  • This * part is the bottom of the first bolt screw valley of the fastening mesh, and is a place where fatigue fracture often occurs.
  • FIG. 4 it can be seen that the maximum stress is applied to the first thread from the fastening side of the bolt 3, and the stress load becomes smaller toward the second and third threads and the open side.
  • the numerical value of the load sharing ratio is 35.6% for the first mountain, 20.6% for the second mountain, 14.5% for the third mountain, and 11. It was 0%, the 5th mountain was 8.5%, the 6th mountain was 5.9%, and the 7th mountain was 3.9%.
  • the black color with a small stress is on the outer peripheral side of the washer (1) and It spreads widely in the center and receives the compressive force from the nut (4) in a wide range, but a white with a large stress appears at the point where it is in contact with the nut (4) at the innermost diameter, and a light gray color. It has the same area as the first thread of the nut, and the dark gray area is greatly expanded. This indicates a situation in which a high Mises equivalent stress is propagated to the contact portion with the nut (4) directly above at the end of the washer (1) on the inner wall side of the bolt hole.
  • the washer fastening structure of the present invention aims to improve the durability of the bolt (3) and extend the fatigue life by reducing the stress load factor of the first thread of the fastening mesh of the bolt (3).
  • FIG. 6 is a partially enlarged view of the washer (1) near the bolt hole (1h) in which the washer (1) and the nut (4) of FIG. 5 are engaged.
  • FIG. 7A is a vertical sectional view of the washer (1), and FIGS. 7B and 7C are perspective views seen from above and below the washer (1).
  • the washer (1) is a washer body (1b) having an upper plane (1u) and a lower plane (1w), and a washer body (1b).
  • ) Has a bolt hole (1h) penetrating the upper plane (1u) and the lower plane (1w), and the washer body (1b) has a stress non-transmission space (1s).
  • the upper plane (1u) of the washer body (1b) refers to the surface on the side that engages with the nut (4).
  • the side of the washer (1) that engages with the nut (4) is referred to as the upper, upper, and upper directions
  • the side of the washer (1) that engages with the object (2) is referred to as the lower and lower sides. , Called downward.
  • the washer body (1b) has a stress non-transmission space (1s) that is concentric and annular around the axis of the bolt hole (1h), and the stress non-transmission space (1s) is It is open to the bolt hole (1h).
  • the stress non-transmission space (1s) may be opened in the bolt hole (1h) and also in the upper plane (1u) of the washer body (1b) (for example, FIGS. 5 to 7), or the bolt hole (1h). It may be opened in the lower plane (1w) of the washer body (1b) as well as in the bolt hole (1h) (for example, FIGS. 13 to 15), or it may be opened in the bolt hole (1h) but in the upper plane (1b) of the washer body (1b).
  • FIGS. 5 to 7 show an example in which the stress non-transmission space (1s) is opened not only in the bolt hole (1h) but also in the upper plane (1u) of the washer body (1b).
  • the stress non-transmission space (1s) is referred to as a first stress non-transmission space (11s) (Aspect A).
  • the first stress non-transmission space (11s) is not open to the lower plane (1w) of the washer body (1b).
  • a transmission space (12s) (Aspect B).
  • the second stress non-transmission space (12s) may or may not be open in the lower plane (1w) of the washer body (1b).
  • the first stress non-transmission space (11s) and the second stress non-transmission space (12s) are collectively referred to as a stress non-transmission space (1s).
  • the first stress non-transmission space (11s) has an extension line of the upper plane (1u) of the washer body (1b) as the first boundary line (B1) in the vertical cross section including the axis of the washer (1).
  • the extension line of the inner peripheral surface (1i) of the bolt hole is the second boundary line (B2), which is below the first boundary line and radially outside the second boundary line, and is located at the position Pt of the first boundary line and the second. It is a space where the line connecting the position Ph of the boundary line is the third boundary line (B3), and the first boundary line (B1), the second boundary line (B2), and the third boundary line (B3) in the vertical cross section.
  • the position Pt where the third boundary line (B3) is in contact with the first boundary line (B1) is the position farthest in the radial direction from the inner peripheral surface (1i) of the bolt hole in the first stress non-transmission space (11s).
  • the first stress non-transmission space (11s) is the boundary position Pt between the first stress non-transmission space (11s) and the upper plane (1u) of the washer body (1b).
  • the nut (4) is located farthest in the radial direction from the inner peripheral surface of the bolt hole (1i).
  • the distance from the extension line of the upper plane (1u) of the washer body (1b) to the position Ph has Ls as the distance to the extension line of the line connecting the screw valley bottoms of).
  • the distance Ls is defined as the distance from the position farthest in the radial direction from the inner peripheral surface (1i) of the bolt hole to the extension line of the line connecting the thread valley bottoms of the nut (4), and the first stress.
  • the boundary position Pt between the non-transmission space (11s) and the upper plane (1u) of the washer body (1b) is the position Ps farthest in the radial direction from the inner peripheral surface (1i) of the bolt hole in the first stress non-transmission space (11s). It is preferable to have (for example, FIGS. 5 to 7). However, the position Ps farthest in the radial direction from the inner peripheral surface (1i) of the bolt hole in the first stress non-transmission space (11s) is the upper plane (1u) of the first stress non-transmission space (11s) and the washer body (1b). It may be in the middle of the third boundary line (B3) connecting the position Pt and the position Ph instead of the boundary position Pt with the position Pt.
  • the second stress non-transmission space (12s) extends radially outward from the position P1 of the inner peripheral surface (1i) of the bolt hole of the washer body (1b) in the vertical cross section including the axis of the washer (1). At present, it reaches the position P2 of the inner peripheral surface (1i) of the bolt hole (see, for example, FIG. 19 (c)) or reaches the position P3 of the lower plane (1w) of the washer body (1b) (see, for example, FIGS. 13 to 15). ))
  • the line is the fourth boundary line (B4)
  • the extension line of the inner peripheral surface of the bolt hole (1i) is the fifth boundary line (B5), or additionally the lower plane (1w) of the washer body (1b) is extended.
  • the line is the sixth boundary line (B6), and the fourth boundary line (B4) and the fifth boundary line (B5) or the fourth boundary line (B4) and the fifth boundary line (B5) in the vertical cross section.
  • the sixth boundary line (B6) which is a concentric annular three-dimensional space formed by rotating the space around the axis of the washer (1).
  • the position farthest from the bolt hole (1h) is set as Ps, and the position Ps is extended to the extension line of the line connecting the screw valley bottom of the nut (4).
  • Has Ls as the distance of.
  • the position P3 on the lower plane (1w) is the position Ps farthest in the radial direction from the inner peripheral surface (1i) of the bolt hole in the second stress non-transmission space (12s).
  • the washer body (1b) extends to the bolt hole 1h below and / or above the stress non-transmission space (1s), and the tip of the extending portion extends the bolt hole.
  • the inner peripheral surface (1i) of the bolt hole to be defined is formed.
  • the inner peripheral surface (1i) of the bolt hole should have a line segment parallel to the axis in the vertical cross section, but may be a point as the ultimate case of the line segment.
  • the extending portion of the washer body (1b) forming the inner peripheral surface (1i) of the bolt hole is for aligning the bolt (3) and the washer (1), and is at least two places, preferably at least three, in the plan view.
  • a space may be formed in a region other than the protrusion (not shown).
  • Such a space is a region where the washer body 1b below the stress non-transmission space (1s) exists in the vertical cross-sectional views of FIGS. 5 to 7, and the stress in the vertical cross-sectional views of FIGS. 13 to 15. This is the region where the washer body (1b) above the non-transmission space (1s) exists.
  • Such a space does not need to be formed, but when it is formed, it forms a space continuous with the stress non-transmission space (1s). However, this space is different from the stress non-transmission space (1s) defined by the present invention.
  • the washer (1) has a stress non-transmission space (1s)
  • the nut (4) and the washer (1s) are fastened.
  • the compressive stress at the time of fastening basically acts at an angle slightly inclined from the outside to the inside in the axial direction or the radial direction of the bolt holes (1h) of the nut (4) and the washer body (1b) (that is, basically). In addition, it acts in the axial direction and in the vertical direction of FIG. 6).
  • the compressive stress in the vertical section of the washer (1), in the region where the stress non-transmission space (1s) exists, the compressive stress is not transmitted in the vertical direction or the horizontal direction, so that the stress non-transmission space (1s) of the washer (1) is not transmitted.
  • the vertical compressive stress in the outer region in the radial direction bends inward in the radial direction above the stress non-transmission space (1s), so that the screws of the bolt (3) and nut (4), especially the lower order. Can act on threaded threads.
  • the maximum angle at which the compressive stress in the vertical direction can be bent is about 45 degrees.
  • the stress moves to the higher-order side threads, and the stress on the lower-order threads, especially the first thread, becomes smaller.
  • the stress non-transmission space (1s) as described above is formed in the washer (1) to lower the order of the bolt (3) and the nut (4).
  • the stress load sharing ratio of the threads of the threads, especially the threads of the first thread can be reduced, and the fatigue strength of the valley bottom of the first thread where the bolt (3) is engaged can be improved.
  • FIG. 8 shows an example of the washer fastening structure on the first side surface as shown in FIGS. 5 to 7, with the same dimensional configuration as the conventional method of FIG. 4, and the radial dimension of the stress non-transmission space (1s), that is, The boundary between the upper plane (1u) of the washer (1) and the stress non-transmission space (11s) at the position farthest from the bolt hole (1h) of the stress non-transmission space (1s) in the upper plane (1u) of the washer (1).
  • the distance Ls from the position Pt to the extension line (4e) of the line connecting the thread valley bottom of the nut (4) is set to about 2.21p (corresponding to 2.21 pitch), and the axial dimension of the stress non-transmission space (11s).
  • FIGS. 8 and 4 Comparing FIGS. 8 and 4, it can be seen that the stress distribution states are significantly different.
  • FIG. 8 it can be seen that light gray and dark gray spread to the fifth mountain.
  • a small white color can be seen in the diagonal thread direction from the vicinity of the washer position Pt (Ps), and this white color indicates the magnitude of stress, and the nut thread threads 3, 4, 5 are in the direction of this white color.
  • the stress is larger and the stress load sharing ratio of the first peak is smaller toward the open side as compared with FIG.
  • the numerical value of the load sharing ratio is 30.2% for the first mountain, 19.4% for the second mountain, 15.2% for the third mountain, 12.6% for the fourth mountain, and 10. 3%, the 6th mountain was 7.4%, and the 7th mountain was 4.9%.
  • FIGS. 9 (a) and 9 (b) show the results of examining the load sharing ratio of each thread of FIG. 7.
  • FIG. 9A shows a load sharing ratio of an example of the fastening structure of the present invention (FIG. 8), and a table comparing the load sharing ratios corresponding to FIG. 4 of the conventional washer fastening structure and FIG. 9B. The comparison is displayed as a bar graph. Comparing these two, the load sharing ratio of the first meshing thread of the conventional bolt is 35.6%, whereas the load sharing rate of the first meshing thread of the bolt of the present invention is 30. The absolute value is 2%, which is 5.4 points, and the relative ratio is about 15%. By reducing the load on the first thread, it is effective in improving the fatigue strength of the bolt meshing on the bottom of the first thread.
  • the elements such as thread shape, member strength, member Young's modulus, Poisson's ratio, fastening torque, and axial force, which are the boundary conditions for bolts, nuts, and washers used in the present invention for FEM analysis, are all the same as those of the conventional method.
  • the improvement effect is confirmed by analyzing by adopting the one specified in JIS (ISO) and comparing. Finer details are used for the screw pitch.
  • FIGS. 4 and 8 the case of M12 ⁇ P1.25 (fine screw) is displayed for reference.
  • An example showing the third boundary line (B3) in a typical shape is shown in FIG. 8, and the FEM analysis result of an example in which Ls is changed with the same shape is shown in the interruption and the lower part of the right figure of FIG.
  • the load sharing ratio is shown by converting it into a value with respect to Ls / p.
  • the diameter of the bolt hole in the washer is set to the minimum gap (0.5 mm) for the screw to pass through, and the gap is the same as that of the conventional bolt hole and the bolt screw, and is straight.
  • the distance Ls is about 2.21p (corresponding to 2.21 pitch), and the distance Lh is about 1.0p (1.0 pitch).
  • the outer peripheral diameter of the seat surface of the nut is 24 mm.
  • the stress non-transmission space (1s) is shown in the vertical cross-sectional views of FIGS. 5 to 7, and the washer body (1b) is opened in the bolt hole (1h).
  • the stress non-transmission space (1s) is three-dimensionally a concentric ring centered on the axis of the bolt hole (1h) of the washer (1) in the vertical cross-sectional view (see FIGS. 7 (b) and 7 (c)). ). That is, the stress non-transmission space (1s) is a three-dimensional space (concentric annular space) formed by rotating the cross-sectional space 1s shown in FIGS. 5 to 7 by 360 degrees around the axis.
  • the stress non-transmission space (1s) with reference to FIGS.
  • FIG. 10 shows the Mises equivalent stress applied when fastening the bolt (3) and the nut (4) in the example of the washer fastening structure on the first side surface by FEM analysis, and the distance Ls (Ls / Ls / It is a graph which summarizes the change of the stress load factor of the 1st mountain when p) is changed, and the Mises equivalent stress distribution map.
  • Ls Ls / p
  • each number is on a downwardly convex curve.
  • the user may select it as a design condition related to various conditions such as material, Young's modulus, and hardness.
  • the load sharing ratio is from 35.6% to 32.8%, 30.2%, 29.1%, 28.7%.
  • the stress index b 4
  • the Nf and lifetime are about 1.39 times, about 1.92 times, about 2.22 times, about 2.33 times, about 2. It is expected to increase by 56 times.
  • FIG. 11 shows an example in which the force F is vertically applied at the position Pt, but in the relationship between the actual bolt, nut, and washer, the direction of the arrow F in FIG. 11 is the upper right with respect to the figure. It may go to the lower left from.
  • the reason is that there is a bolt on the right side of the position Pt and there is a nut seat surface on the position Pt, so the bolt (3) and nut (4) pass the force at the thread, and the compressive force is the nut seat.
  • This is due to stress concentration on the innermost peripheral portion (here, position Pt) of the contact portion between the surface and the washer (1). Therefore, for example, the stress line 1 mg of the Mises equivalent stress distribution curve also rotates slightly clockwise (in FIG. 8).
  • the entire compressive stress distribution including the stress line 1 mg is inclined and separated from the boundary line (B3) on the left half side of FIG. 11 in the clockwise direction, so that there is no adverse effect on the evaluation of the present invention.
  • the region of white with high stress, light gray with slightly high stress, and dark gray with slightly weak stress is the force F near the position Pt where the nut bearing surface and washer (1) contact. It shows the direction and spreads in the washer (1) and nut (4). The direction of this stress appears to be from the position Pt toward the fourth thread of the screw.
  • the stress non-transmission space (1s) is preferably the first stress non-transmission space (11s) satisfying the following conditions (this). Aspects are referred to as Aspect A). That is, the first stress non-transmission space (11s) has a vertical cross section including the axis of the washer (1) as shown in FIGS. 5 to 7, and particularly when referring to FIG. -The extension line of the upper plane (1u) of the washer body (1b) is set as the first boundary line (B1), and the extension line of the inner peripheral surface (1i) of the bolt hole is set as the second boundary line (B2).
  • the third boundary line is a line that is below B1) and radially outside the second boundary line (B2) and connects the position Pt of the first boundary line (B1) and the position Ph of the second boundary line (B2).
  • the radial distance Ls from the position Ps to the extension line (4e) of the line connecting the screw valley bottoms of the nut (4) exceeds 0.5 times the screw pitch p of the nut (4) and is 6 times or less.
  • the distance Lh in the axial direction from the first boundary line (B1) to the position farthest in the axial direction of the first stress non-transmission space (11s), preferably the first boundary line (B1) is the second boundary line (B2).
  • the position where it intersects with () is Po, and the distance in the axial direction from the position P réelle to the position Ph is the distance Lh, but the thickness T of the washer (1) is 0.01 times or more the screw pitch p of the nut (4). It is in the range of 99% or less of.
  • FIGS. 5 to 7 show an example of a preferable mode of the first stress non-transmission space (11s), but the washer body (1b) is opened in the bolt hole (1h) and also in the upper plane (1u). It has a first stress non-transmission space (11s) that opens. The first stress non-transmission space (11s) is not open to the lower plane (1w) of the washer body (1b).
  • the third boundary line (B3) between the first stress non-transmission space (11s) and the washer body (1b) is the inner peripheral surface (1i) of the bolt hole from the position Pt of the upper plane (1u).
  • the third boundary line (B3) is an arc or an elliptical arc. If it is an arc, the center point is directly below the Pt passing through the inside of the washer, and if it is an elliptical arc, Pt is preferably the apex of the minor axis of the ellipse. Further, since the force from the nut (4) is applied near the position Pt of the upper plane (1u), the connection method between the upper plane (1u) and the third boundary line (B3) is also a stress concentration relaxation curve.
  • the stress concentration relaxation curve has no corners and moves from the straight line of the upper plane (1u) to the third boundary line (B3) with a gentle curve.
  • the connection method between the third boundary line (B3) and the bolt hole inner peripheral surface (1i) near the position Ph of the bolt hole inner peripheral surface (1i) is from the nut (4) and the object to be fastened (2). Since almost no force is applied, it does not necessarily have to be a stress concentration relaxation curve.
  • the third boundary line (B3) may start with an upwardly convex curve from the position Pt and inflection to form a downwardly convex curve to reach the position Ph, as shown in FIG.
  • the first stress non-transmission space (11s) has an upwardly convex cross-sectional shape shown in FIGS. 5 to 7 in the vertical cross section, but three-dimensionally, the bolt hole (1h) of the washer (1) ) Is a concentric ring centered on the axis (see FIGS. 7B and 7C). That is, the first stress non-transmission space (11s) is a three-dimensional space (concentric annular space) formed by rotating the cross-sectional space (11s) shown in FIGS. 5 to 7 by 360 degrees around the axis. ..
  • the first stress non-transmission space (11s) is opened in the bolt hole (1h) in the vertical cross section of the washer (1). Since the first stress non-transmission space (11s) is opened in the bolt hole (1h), the transmission of the fastening force on the bolt hole side of the washer body (1b) in the axial direction is blocked, so that the fastening force is blocked on the bolt hole side. The force applied to the lower ridges of the fastening mesh of a certain bolt is reduced.
  • the first stress non-transmission space (11s) is also open to the upper plane (1u) of the washer body (1b) in the vertical sectional view of the washer (1).
  • the first stress non-transmission space (11s) is also open to the upper plane (1u) of the washer body (1b), it is located near the low-order threads of the nuts (4) and bolts (3).
  • the effect of reducing the force applied to the lower-order ridges of the bolt (3) is strong and reliable, and the load reduction effect can be strong and reliable even if the depth of the space is small.
  • the formation of the space in 1b) is also easy.
  • the distance Ls is, for example, 0.8 times or more, 1 time or more, 1.5 times or more, 2 times or more, 2.5 times or more the length of the screw pitch p of the nut (4). It may be in the range of 3 times or more, 5 times or less, 4 times or less, and 3.5 times or less. In particular, it is preferably 2.0 times or more and 4 times or less.
  • the axial distance Lh of the first stress non-transmission space (11s) is set so as to secure a space in which Ph does not come into contact with the nut bearing surface even if the washer (1) is elastically deformed, and the screw pitch is set. It may be as shallow as 0.01 to 0.1 times, and may be deep to reduce the weight of the washer (1). In one preferred embodiment, the distance Lh is, for example, in the range of 0.1 times or more the screw pitch p of the nut (4) to 90% or less of the following thickness T of the washer (1), and further 1 of the screw pitch p. The range may be from double or more to 65% or less of the thickness T of the washer (1).
  • the distance Lh is a distance on the inner peripheral surface (1i) of the bolt hole.
  • the distance Lh may be the longest distance in the axial direction of the first stress non-transmission space (11s), but may not be the longest distance in the axial direction of the first stress non-transmission space (11s).
  • the longest distance in the axial direction of the first stress non-transmission space (11s) is the nut (4). It is preferable that the thickness T of the washer (1) is 99% or less from 0.01 times the screw pitch p of.
  • the longest distance in the axial direction of the distance Lh or the first stress non-transmission space (11s) is from 0.5 times or more the screw pitch p of the nut (4) to the thickness of the washer (1). It is in the range of 95% or less of T, and may be in the range of 30 to 90% and 50 to 90%.
  • the longest distance in the axial direction of the distance Lh or the first stress non-transmission space (11s) may be 1% or more, 3% or more, 5% or more, 10% or more of the thickness T, and the thickness T. It may be 50% or less, 30% or less, 20% or less, 10% or less, and 5% or less.
  • the third boundary line (B3) of the first stress non-transmission space (11s) is formed on the upper plane (1u) of the washer body (1b).
  • the relative stress is 95% on the bolt hole side of the stress distribution line on the bolt hole side with reference to the magnitude of the Mieses equivalent stress applied vertically downward from the position Pt.
  • the Mises equivalent stress distribution is a technique for visualizing the state of force inside a ductile material that cannot be actually seen. It subdivides the inside of a substance, calculates a vector in three axial directions, and expresses it collectively. Therefore, the direction of the internal force and the magnitude of the force (stress) are expressed as a distribution. It is a method known in strength of materials, and a typical formula is as follows, and the Mises stress ⁇ Mises is expressed by the following formula using the principal stresses ⁇ 1 , ⁇ 2 , and ⁇ 3 .
  • the present invention uses the Mises equivalent stress distribution in order to improve the conventional method according to the purpose by comparing the states when the bolts, nuts, and washers are fastened with the axial force specified by JIS.
  • the fastening structure of the invention was evaluated.
  • the stress applied to the washer is never even, and is concentrated on the inner peripheral side of the nut (bolt side) or at a considerably higher ratio (from various simulation results) on the inner peripheral side of the nut, and on the outer peripheral side of the nut.
  • the load sharing is small (there are many black parts in the simulation). Therefore, even if it is considered that the parts are concentrated on the contact point Pt between the nut and the washer on the inner peripheral side, by arranging many members of the washer body on the bolt hole side of the washer, it becomes stronger and the washer can be prevented from buckling. It has a safe fastening structure.
  • the stress distribution 1 m equivalent to Mises in FIG. 11 (a) is generally a post-processing of the calculation by FEM analysis of the distribution state of the compressive stress generated inside the washer when a force is applied perpendicularly to the position Pt. It is expressed as.
  • the third boundary line (B3) is also shown, but in the present invention, the washer (1) provides a flat upper plane (1u) without the first stress non-transmission space (11s). Assuming that it has, when a force F is applied to the position Pt (boundary with the first stress non-transmission space (11s)) on the upper plane (1u) of the assumed washer (1), the assumed washer (1).
  • FIG. 11A also schematically shows the Mises equivalent stress distribution obtained in this way.
  • the stress distribution equivalent to Mieses depends on the Young ratio and Poisson ratio of the washer, and the magnitude of the stress depends on the force F, but the stress distribution situation is based on the relative stress distribution that does not depend on the magnitude of the force F.
  • an arrow curve 1 m (specifically, 1 ma to 1 mg; a vector indicating the magnitude and direction of the force, which represents the stress distribution equivalent to Mieses shown in FIG. 11 (a), is a vector indicating the magnitude and direction of the force.
  • the stress 1 ma in the innermost part is the largest, and the stress increases as the stress increases to the outside and farther from the inside of the semicircle, which is the range in which the force diffuses. It becomes smaller in order (from 1 mb to 1 mg).
  • the third boundary line (B3) is an example formed on the side (bolt hole side) farther than the smallest stress line 1 mg from the Pt direct perpendicular line.
  • the stress line 1 m (1 ma to 1 mg) in FIG. 11A represents a stress distribution in seven stages, it is schematically an arbitrary stress distribution.
  • FIG. 11B shows the magnitude of the force in this state actually obtained and shown in an eight-step gradation pattern using black (high stress), gray, light gray, and white (low stress). The darker the color, the larger the stress.
  • the stress of 1 ma directly below the central portion Pt to which the force F is applied is the largest, and the portion of the outermost line 1 mg from the position Pt is the smallest. This stress further extends to the outside of the outermost circumference line 1 mg, but the magnitude of the stress outside the outer circumference line 1 mg (on the right side of the line 1 mg in the figure) is extremely small, and the influence as stress can be ignored. It is getting smaller.
  • the end of the washer (1) on the bolt hole side is perpendicular to the upper plane (1u) of the washer (1) and is in the axial direction of the bolt (3).
  • the structure was such that the bolt hole end was 100% directly underneath the entire stress of the force F applied to the bolt hole end.
  • the third boundary line (B3) forming the first stress non-transmission space (11s) of the washer (1) is added directly below the position Pt in the above-mentioned Mieses equivalent stress distribution curve.
  • the force applied to the position Pt is shared on the bolt hole side from directly below the position Pt, so that the fatigue strength of the washer 1 is improved.
  • the third boundary line (B3) is the stress distribution of 80%, 70%, 50%, 30%, 20%, 10%, or 5% of the stress applied directly under the position Pt in the Mises equivalent stress distribution curve. It may be on the bolt hole side of the curve. It is particularly preferable that the boundary line B3 is on the bolt hole side of the Mises equivalent stress distribution curve with respect to the stress distribution curve of 5% of the stress applied immediately below the position Pt.
  • the third boundary line (B3) when the third boundary line (B3) is on the bolt hole side of the stress distribution curve equivalent to Mieses immediately below the position Pt, for example, the stress distribution curve of X%, the third boundary line (B3) Does not have to completely follow the X% stress distribution curve 1 m, it may be on the bolt hole side of the X% stress distribution curve, especially from the upper plane to the lower plane of the washer (1) to a predetermined depth. After extending (usually with an upwardly convex curve), while maintaining the stress deconcentration line, toward the bolt hole side (in the direction parallel to the upper plane of the washer (1), that is, downward) It may be bent (as a convex curve). For example, the third boundary line (B3) in FIG.
  • the third boundary line (B3) in the longitudinal section may be configured to start as an upwardly convex curve from position Pt and inflection to reach position Ph as a downwardly convex curve.
  • an upwardly convex or downwardly convex curve means that a straight line connecting any two points of the curve has a point between the two points above or below the straight line, respectively, with respect to the curve. The tangents are above or below, respectively).
  • the third boundary line (B3) is such a curve, the washer (1) is near the bolt hole of the washer body (1b) while achieving a small stress concentration by the first stress non-transmission space (11s).
  • the decrease in strength can be reduced, the amount of processing for forming the first stress non-transmission space (11s) can be reduced, and it can be advantageous for alignment with the bolt (3).
  • the third boundary line (B3) is on the bolt hole side of the stress distribution curve of 5% of the stress applied directly under the position Pt in the stress distribution curve equivalent to Mieses, and is near the upper plane (1u) of the washer (1). It is particularly preferable to bend the bolt hole side from a position where the depth reaches a certain magnification (for example, 0.01 times to 0.03 times) or more of the screw pitch while following the stress distribution curve of 5%.
  • the radial dimension of the distribution state of the specific stress magnitude initially expands in the depth direction, but the vector line (1 m) through which the force flows as shown in FIG. 11 (a).
  • the large stress in the center of FIG. 11B gradually propagates and expands, and the region where the stress is slightly weakened is gradually expanded around.
  • the black range which represents the maximum stress, is reduced from the middle.
  • the Mises equivalent stress distribution range may be considered as a straight line extending from that position to the lower surface in the axial direction at a position deeper than the position where the radial dimension is maximized.
  • the third boundary line (B3) even if the radial dimension of the stress large range of the stress distribution diagram is reduced in the depth direction, the stress of the surrounding stress is propagated. Since it is enlarged, it is not preferable that the radial dimension of the third boundary line (B3) is reduced.
  • the third boundary line (B3) expands in the bolt hole direction from the position Pt and reaches Ph, and the third boundary line (B3) from the position Pt to Ph decreases in the depth direction. It is preferable that there is nothing, and that it only expands.
  • the lower surface of the object to be fastened (2) or the screw may be evaluated at a pitch of 10 to 20 p or more. In another aspect, the evaluation may be performed from the nut-side plane of the object to be fastened (2) to a depth of 0.1 to 1 pitch or 1 to 2 pitch of the screw.
  • the region where the third boundary line (B3) of the first stress non-transmission space (11s) should not exist is a small region from the line 1ma directly under Pt to the bolt hole side. It is preferable that the length of the third boundary line (B3) starting from the position Pt in the radial direction toward the bolt hole is, for example, a stress concentration relaxation curve with a screw pitch of 0.01p to 0.5p.
  • the stress concentration relaxation curve has been described above. For example, since the point where the first boundary line (B1) and the third boundary line (B3) meet is Pt, the contact form is the third boundary line (B3).
  • the third boundary line (B3) starting from the position Pt is preferably a stress concentration relaxation curve from the position Pt toward the bolt hole side at least from a screw pitch of 0.01p to 0.5p.
  • the hole side does not necessarily have to be the stress concentration relaxation curve.
  • FIG. 12 shows a modified example of the first stress non-transmission space (11s) in a vertical sectional view.
  • FIG. 12A is composed of one ellipse or a part of a large arc.
  • the first stress non-transmission space (11s) is formed symmetrically on both planes of the washer (1), and both both sides of the washer (1) can be used as upper planes.
  • the third boundary line (B3) forming the first stress non-transmission space (11s) is extended downward by the required amount from Pt to the bolt hole side via the turning point.
  • either side of the washer (1) may be used as the upper plane, but it is formed on the upper plane.
  • the stress non-transmission space acts as the first stress non-transmission space, or the stress non-transmission space formed on the lower plane acts as the second stress non-transmission space.
  • the stress non-transmission space having the larger distance Ls functions as a substantial stress non-transmission space.
  • the compressive force passes between the position Pt where the washer (1) touches the nut (4) and the point where it touches the object to be fastened (2), and the bolt hole side (so-called peninsula shape) from between these two points.
  • the protruding part (of) exists as a part for centering with the bolt.
  • 12 (d) shows a curved shape in which the central portion is wavy or partially recessed. There may be various other shapes.
  • the position Ps farthest in the radial direction from the bolt hole (1h) in the first stress non-transmission space (11s) is the first stress non-transmission space (11s) in the upper plane (1u) of the washer. This is an example in which the position is farther from the bolt hole (1h) than the position Pt forming the boundary point with.
  • the stress non-transmission space (1s) is preferably a second stress non-transmission space (12s) satisfying the following conditions (this aspect). Is referred to as aspect B). That is, the second stress non-transmission space (12s) is the inner peripheral surface (1i) of the bolt hole of the washer body (1b) in the vertical cross section including the axis of the washer (1) as shown in FIGS. 13 to 15 and 19.
  • the line extending outward in the radial direction from the position P1 to the position P2 on the inner peripheral surface (1i) of the bolt hole or to the position P3 on the lower plane (1w) of the washer body (1b) is the fourth boundary line (B4).
  • the extension line of the inner peripheral surface (1i) of the bolt hole is the fifth boundary line (B5), or optionally, the extension line of the lower plane (1w) of the washer body (1b) is the sixth boundary line (B6). It is a space to do
  • the second stress non-transmission space (12s) has a vertical cross section. -Preferably, the position farthest in the radial direction from the peripheral surface (1i) of the bolt hole is Ps, and the radial distance Ls from the position Ps to the cylindricity of the line connecting the thread valley bottom of the nut is the screw of the nut (4). It is in the range of length exceeding 0.5 times the pitch p and 6 times or less.
  • the eaves thickness Th which is the shortest dimension in the axial direction from the upper plane (1u) of the washer body (1b) to the second stress non-transmission space (12s), is 1% of the thickness T of the washer (1). That is all.
  • FIGS. 13 to 15 shows an example of a preferable embodiment of the second stress non-transmission space (12s), but the washer body (1b) is opened in the bolt hole (1h) and also in the lower plane (1w). It has a second stress non-transmission space (12s) that opens.
  • the second stress non-transmission space (12s) is not open to the upper plane (1u) of the washer body (1b).
  • the fourth boundary line (B4) between the second stress non-transmission space (12s) and the washer body (1b) has a rising edge (Br) that rises almost vertically from the lower plane (1w), and is a curved corner close to an arc.
  • the rising portion (Br) rising substantially vertically from the lower plane (1w) may be within an angle of ⁇ 20 degrees with respect to the vertical direction in consideration of manufacturing accuracy.
  • the corner portion (Bc) is not limited, but in the vertical sectional views of FIGS.
  • the line segment of the corner portion (Bc) is 20 to 25 degrees, particularly 25 degrees with respect to the axis z. It may be a portion from a position in contact with a straight line to be formed to a position in contact with a straight line forming 65 to 70 degrees, particularly 65 degrees with respect to the axis z.
  • the end of the inner circumference of the bolt hole (Be) is from the end of the corner (Bc) (the position in contact with the straight line forming 65 to 70 degrees, particularly 65 degrees with respect to the axis z) to the inner peripheral surface of the bolt hole (1i). is there.
  • the second stress non-transmission space (12s) has an upwardly convex cross-sectional shape shown in FIGS. 13 to 15 in the vertical cross-sectional view, but three-dimensionally, the bolt hole of the washer (1) ( It is a concentric ring centered on the axis of 1h) (see FIGS. 15B and 15C). That is, the second stress non-transmission space (12s) is a three-dimensional space (concentric annular space) formed by rotating the cross-sectional space shown in FIGS. 13 to 15 by 360 degrees around the axis.
  • the second stress non-transmission space (12s) is opened in the bolt hole (1h) in the vertical cross section of the washer (1). Since the second stress non-transmission space (12s) is opened in the bolt hole (1h), the axial transmission of the fastening force on the bolt hole side of the washer body (1b) is reduced, so that it is on the bolt hole side. The force applied to the lower ridges of the fastening mesh of a certain bolt (3) is reduced.
  • the fastening force (compressive stress) from the contact surface between the washer (1) and the nut (4) to the bolt (3) is determined by the presence of the second stress non-transmission space (12s).
  • the angle (direction in which the compressive stress extends to the bolt hole side) from the outside of the position Ps farthest in the radial direction from the inner peripheral surface (1i) of the bolt hole in the stress non-transmission space (12s) to the bolt hole side is upright from the position Ps.
  • the limit is an elevation angle of approximately 45 degrees with respect to the axis z from the vicinity of passing through the upper portion (Br) and beyond the apex of the curve at the corner portion (Bc).
  • the distance Ls is preferably 0.5 times or more and 6 times or less the length of the screw pitch p of the nut. In one preferred embodiment, the distance Ls is 0.7 times or more, 1 time or more, 1.5 times or more, 2 times or more, 2.5 times or more, 3 times or more the length of the screw pitch p. Further, it is preferably 5 times or less, 4.5 times or less, 4 times or less, and 3.5 times or less.
  • the distance Ls is 2 pitches or more and 4 pitches or less.
  • the radial dimension of the second stress non-transmission space (12s) is set to an appropriate dimension or less, the outer diameter dimension of the nut and washer can be kept small while the stress applied to the low-order thread is sufficiently small. It is preferable because it can be done.
  • the washer body (1b) has an eaves portion (1p) above the second stress non-transmission space (12s).
  • the eaves portion (1p) is a member for centering the bolt (3) with respect to the bolt hole (1h), and the tip of the eaves portion (1p) constitutes the inner peripheral surface of the bolt hole (1h). Just do it.
  • the eaves portion (1p) forming the inner peripheral surface of the bolt hole (1h) does not necessarily exist on the entire circumference of the bolt hole (1h) in the plan view of the washer body (1b), but exists on the entire circumference. It is preferable to define a circular bolt hole (1h).
  • the vertical thickness in the figure may be as small as long as the strength of the eaves (1p) is maintained, and the smaller the thickness, the more the contribution to stress transmission.
  • the minimum thickness Th of the eaves portion (1p) is 1% or more of the thickness T of the washer, but it is desirable that it is 0.1 times or more and 0.7 times or less. More preferably, Th is 0.2T ⁇ Th ⁇ 0.6T, and even more preferably 0.22T ⁇ Th ⁇ 0.5T.
  • this eaves 1p can be partially reduced, and if the shape is the thinnest on the way to the inner peripheral surface Ii of the bolt hole through the corner Bc, centering with the bolt on the innermost diameter side It is possible to secure the length t of the inner peripheral surface that can be easily performed.
  • the fourth boundary line (B4) between the washer body (1b) and the second stress non-transmission space (12s) is approximately the same as the lower plane (1w) of the washer body (1b).
  • the bolt hole inner peripheral side end (Be) connected to the bolt hole inner peripheral surface (1i), and the rising portion (Br) and the bolt hole inner peripheral end (Be). It has a corner portion (Bc) to be connected.
  • the corner portion (Bc) is entirely curved or It is preferably composed of a combination of curved lines and straight lines, and is composed of stress concentration relaxation lines having no corners where the straight lines intersect.
  • the corner portion (Bc) is not limited, but is 20 to 25 degrees with respect to the axis z, particularly from a position in contact with a straight line forming 25 degrees with respect to the axis z. It may be a portion up to a position tangent to a straight line forming 65 to 70 degrees, particularly 65 degrees, and there is a position where a straight line having an elevation angle of 45 degrees with respect to the axis z touches the fourth boundary line (B4). It is a part.
  • the corner portion (Bc) may be composed of, for example, a straight line having an elevation angle of about 40 to 50 degrees, particularly about 45 degrees.
  • the connecting portion between the corner portion (Bc) and the rising portion (Br) It is preferable that the connecting portion between the corner portion (Bc) and the inner peripheral side end portion (Be) of the bolt hole is joined by a curved line so as not to form a corner.
  • the corner portion (Bc) may be formed by an arc, an elliptical arc, or a shape close thereto.
  • the connection point between the inner peripheral surface (1i) of the bolt hole of the washer body (1b) and the fourth boundary line (B4) is a nut. It does not have to be a stress concentration relaxation line because the force applied between the objects to be fastened hardly reaches or is small.
  • the fourth boundary line (B4) between the washer body (1b) and the second stress non-transmission space (12s) is the lower plane of the washer body (1b). From the rising portion (Br) rising almost vertically from (1w), a corner portion (Bc) is formed by being connected to an arc or an elliptical arc, and then the inner peripheral surface of the bolt hole is formed by the inner peripheral end portion (Be) of the bolt hole whose curvature is further reduced. (1i) may be reached.
  • Such a fourth boundary line (B4) is a stress concentration relaxation curve except for the connection point with the lower plane (1w) and the inner peripheral surface of the bolt hole (1i), and is a second stress non-transmission space having this shape (1i). 12s) is easy to form. Further, when the position P where the straight line having an elevation angle of 45 degrees with respect to the axis is in contact with the corner portion (Bc) is close to the upper plane (1u), the compressive stress transmitted from the object to be fastened (2) to the screw is not transmitted as the second stress. The position around the outside of the space (12s) has an effect of being farther from the inner peripheral surface (1i) of the bolt hole, which is preferable.
  • the position P where the corner portion (Bc) is in contact with a straight line having an elevation angle of 45 degrees with respect to the axis is located at an axial distance of 1/2 or more of the thickness T of the washer (1) from the lower plane (1w) of the washer body (1b). It is preferably less than or equal to the length of one pitch of the screw from the position P3 (Ps) of the starting point of the rising portion (Br) on the lower plane (1w) of the washer body (1b) toward the inner peripheral surface (1i) of the bolt hole. It is preferable to have.
  • the rising portion (Br) (from the lower plane (1w) to the position where a straight line having an elevation angle of 20 to 25 degrees with respect to the axis touches the fourth boundary line (B4)) is not limited, but is 1 of the thickness T of the washer (1). It is preferable to have an axial length of / 4 to 1/3 or more.
  • the end of the inner circumference of the bolt hole (Be) (from the position where the straight line with an elevation angle of 65 to 70 degrees with respect to the axis touches the fourth boundary line (B4) to the inner peripheral surface of the bolt hole (1i)) is the connection point with the corner (Bc).
  • the shape is such that the elevation angle formed by the tangent line with respect to the axis gradually increases from the bolt hole inner peripheral surface (1i), and the maximum elevation angle is preferably 90 degrees or less.
  • the minimum thickness of the eaves (1p) formed above the bolt hole inner peripheral end (Be) (thickness t of the bolt hole inner peripheral surface (1i) in FIG. 14) is the thickness T of the washer (1). It is preferably in the range of 3 to 20%, more preferably 5 to 15%.
  • the bolt hole inner peripheral end portion (Be) may have various deformations as shown in FIGS. 19 and 20, in addition to the shape shown in FIG. 13, and further, the bolt hole inner peripheral end portion (Be) does not exist.
  • the middle or the end of the corner portion (Bc) may be a connection portion with the inner peripheral surface (1i) of the bolt hole.
  • FIG. 16 shows the stress situation shown by the Mises equivalent stress distribution by performing FEM analysis on the washer fastening structure of the aspect B shown in FIGS. 13 to 15.
  • white high stress
  • the compressive stress is large, and the thread faces the fourth direction.
  • Light gray small stress
  • the nut threads are applied to the 2nd to 5th threads.
  • white high stress
  • Light gray is on the first and second threads of the bolt screw, but the area is small. Light gray is No.
  • 17 (a) and 17 (b) show the results obtained by FEM analysis in the case of fastening with the washer fastening structure of the aspect B shown in FIG. 16 and the case of fastening with a conventional washer.
  • a comparison of the load sharing ratios of the mountains is shown in a list, and the comparison is shown in a bar graph in FIG. 17 (b).
  • the load sharing ratio at the first thread of fastening engagement is 35.6% in the case of the conventional structural washer, whereas it is 32.3% in the first thread in the model of aspect B (examples of FIGS. 13 to 15).
  • the absolute value is reduced by 3.3 points, and the relative value is reduced by about 9%.
  • Aspect B is equivalent to increasing the ratio (Ls / p) of the radial distance Ls of the second stress non-transmission space (12s) to the pitch p, that is, increasing Ls, but the first meshing peak.
  • the load sharing ratio of the thread tends to decrease. The reason is that the force from the washer is applied to the nut bearing surface on the outer peripheral side of the position Ps (P3), which is the end of the distance Ls, and the force from the input position toward the nut thread increases diagonally, and the nut This is because the stress increases after the third thread on the open side of the thread, so that the load sharing ratio that enters the first thread decreases relatively.
  • FIG. 18 shows the relationship between the change in the distance Ls (Ls / p) of aspect B and the load sharing rate of the first mountain of meshing.
  • FIG. 18 summarizes the effects of changing the washer distance Ls of aspect B.
  • the shape of the second stress non-transmission space (12s) has the same depth to the inner peripheral surface of the bolt hole (1i), and the distance Ps (up to position P3) in model 3 compared to model 2 Distance) is longer in the radial direction.
  • the white portion having a large stress extends from the first thread to the higher-order thread side from the upper figure to the middle figure and the lower figure. From these figures, the load sharing ratio for the first thread of the bolt screw at each black spot position is 35.6% in the upper figure (conventional washer), 32.3% in the middle figure, and 30.9% in the lower figure. It was.
  • the load sharing ratio of the first thread of the screw decreases substantially linearly as the distance Ls increases, and the load sharing ratio of the first thread of the bolt screw decreases from 35.6% to 32.3% as the distance Ls increases. It has decreased by about 9% relatively.
  • the load sharing ratio is from 35.6% to 34.5%, 32.3%, 30.9%, 30.3.
  • FIG. 19 shows a schematic diagram of a modified example of the second stress non-transmission space (12s).
  • the fourth boundary line (B4) is the boundary line between the washer body (1b) and the second stress non-transmission space (12s).
  • FIG. 19A is an example in which the axial length t of the inner peripheral surface (1i) of the bolt hole is longer than the minimum thickness Th of the eaves portion (1p).
  • FIG. 19B shows the structure of the stress concentration relaxation curve from the contact position P3 (Ps) to the rising portion (Br) of the lower plane (1w) of the object to be fastened (2) and the washer (1).
  • FIG. 19 (c) shows a second stress non-transmission space (12s) that is convex from the inner peripheral surface of the bolt hole toward the outside in the radial direction in the middle of the thickness of the washer body (1b).
  • (12s) is an example in which the washer body (1b) is not opened in the vertical planes (1u, 1w).
  • FIG. 19C is an example in which two washers of FIG. 19B are attached facing each other.
  • FIG. 19 (c) is provided near the nut (4) to provide the first meshing thread.
  • the thread load sharing ratio can be reduced.
  • the upper and lower planes of the washer are the same, so that there is no misuse during use.
  • -Fig. 19 (d) shows a shape that takes into consideration the centering of the washer (1), and shows a method of increasing the length t of the inner peripheral surface of the bolt hole (see the shape on the bolt hole side) and the nut side on the outer peripheral side.
  • a modified example of a method see the protrusions on the outer peripheral side of the washer body (1b) in which a ring shape or several protrusions are provided on the bolt and the outer peripheral portion of the nut is used to align the center with the bolt is shown. ..
  • FIG. 20 has a curve or a straight line at the rising portion (Br) on both sides of the corner portion (Bc) and the inner peripheral end portion (Be) of the bolt hole, and the middle of the curve or the straight line, that is, the corner portion (Bc) is a straight line.
  • the rising portion (Br) and the inner peripheral end portion (Be) of the bolt hole are also straight lines, and only the connecting portion of each line is connected by the stress concentration relaxation curve.
  • the washer body (1b) is formed with a stress non-transmission space (1s) so as to be connected to the upper plane (1u), lower plane (1w), and bolt hole inner peripheral surface (1i) of the washer body (1b).
  • chamfering is basically unnecessary, but depending on the shape of the stress non-transmission space (1s), it may be particularly arc-shaped or elliptical arc-shaped. It may be chamfered.
  • the position Ph on the inner peripheral surface (1i) side of the bolt hole of the washer body (1b) in the first stress non-transmission space (11s) may be configured as a part of the stress concentration relaxation curve, or a part of the stress concentration relaxation curve. Although not, it may be chamfered arbitrarily.
  • the position P3 on the lower plane (1w) of the washer body (1b) in the second stress non-transmission space (12s) or the position P2 on the inner peripheral surface (1i) side of the bolt hole may be configured as a part of the stress concentration relaxation curve. Although it is not a part of the stress concentration relaxation curve, it may be chamfered arbitrarily.
  • the corners of the bolt hole forming portion of the washer body may be chamfered.
  • the chamfer in the prior art is often arcuate or triangular in vertical cross section, but its dimensions are fine, with a maximum screw pitch p of less than 0.35p, more than 0.5p, and more. Since it is not the same as the pitch p, it can be clearly distinguished from the stress non-transmission space (1s) of the present invention.
  • the outer peripheral dimension of the washer (1) is preferably the same as or slightly larger than the outer peripheral dimension of the nut (4).
  • the outer peripheral dimension of the washer (1) can be considered as the diameter of the circle inscribed in the washer (1) in the plan view looking into the screw hole of the washer (1).
  • the outer peripheral dimension D of the washer (1) may be the same as the outer peripheral dimension of the washer (1) that is standardly used corresponding to the outer diameter of the bolt used in the first aspect of the present invention.
  • the outer peripheral dimension of the washer (1) may be 1.8 times or more the inner diameter of the washer (1) (or the outer diameter of the bolt), and is 1.9 times or more, 2 times or more, 2 times or more. .
  • the outer peripheral dimension D of the washer (1) may be 4 times or less, 3 times or less, and 2.5 times or less the inner diameter of the washer (1) (or the outer diameter of the bolt).
  • the outer peripheral dimension of the nut (4) can be considered as the diameter of a circle inscribed in the nut (screw shaft portion, or flange portion in the case of a flange nut) in a plan view looking into the screw hole of the nut (4).
  • the outer peripheral dimension D of the nut (4) is the same as the outer peripheral dimension of the nut (4) which is standardly used corresponding to the outer diameter of the bolt (3) used in the first aspect of the present invention.
  • the outer peripheral dimension of the nut (4) may be 1.8 times or more the inner diameter of the nut (4) (or the outer diameter of the bolt) 1.9 times or more and 2 times or more.
  • the outer peripheral dimension D of the nut (4) may be 4 times or less, 3 times or less, and 2.5 times or less the inner diameter of the nut (4) (or the outer diameter of the bolt).
  • the contact surface between the upper plane (1u) of the washer (1) and the lower plane (4w) of the nut (4) is the axis.
  • the radius of the inscribed circle is twice the distance between the line (4e) connecting the roots of the threads of the nut (4) and the axis of the nut (4). It may have a dimension of 0.8 times or more, further 0.9 times or more, and 1.0 times or more the sum of the distance Ls and the distance Ls.
  • the lower plane of the washer (1) in the plan view of the fastening structure viewed from the axial direction is a circle inscribed in the contact surface centered on the axis, the radius of the inscribed circle is the line connecting the valley bottoms of the threads of the nut (4) (4e). ) And twice the distance (radius) of the axis and 0.8 times or more the sum of the distance Ls, and further 0.9 times or more and 1.0 times or more.
  • the outer circumference of the washer body (1b) may be larger than the outer circumference of the upper plane (1u) in contact with the nut (4).
  • the washer body (1b) may be cut out at an elevation angle of, for example, 30 to 60 degrees, and further 40 to 50 degrees at the connection portion between the outermost circumference (1 Exam) and the upper plane (1u).
  • the size of the notch portion (1d) is the dimension in the thickness direction of the washer body (1b), and may be half or less, further one-third or less of the thickness T of the washer body (1b).
  • the notch portion (1d) can have a shape corresponding to the flange portion of the flange nut.
  • the nut (4) may be a polygonal nut without a flange portion (usually a hexagon nut), but a flange nut having a flange portion (4f) is preferable.
  • the flange nut has a screw shaft portion and a flange portion (4f) widened from the screw shaft portion, and the bottom surface (seat surface) on the flange portion (4f) side is a flat surface.
  • the outer peripheral dimension D'of the bottom surface (seat surface) on the flange portion side has the above-mentioned dimension in order to secure a predetermined fastening area.
  • the screw shaft portion of the flange nut can be smaller than the outer peripheral dimension D of the bottom surface (seat surface), and the material cost can be saved.
  • the flange portion (4f) in the flange nut bears (increases) the required fastening area in order to secure the fastening force between the nut (4) and the washer (1), and has the required axial thickness.
  • an elevation angle of about 70 degrees or less is preferable in the vertical cross section.
  • the material of the screw shaft portion may be reduced as the shape having the portion).
  • the fastening force between the washer (1) and the nut (4) is from the fastening surface of the washer (1) and the nut (4) to the nut (4) and near the outer circumference of the nut (4) (at a position far from the bolt hole).
  • Compressive stress in the elevation angle direction of approximately 40 to 45 degrees or more toward the screw of the bolt (3) is important, and the stress transmission in the portion with a smaller elevation angle is not directed to the screw of the nut (4) or the force is small.
  • a portion of the nut (4) may be absent and therefore an inclined portion and a screw shaft portion of the flange nut (see FIG. 3).
  • the vicinity of the outer peripheral surface of the flange portion of the flange nut may be substantially perpendicular to the seat surface for strength reinforcement, and the thickness of that portion is, for example, 0.5 p with respect to the screw pitch p.
  • the outer peripheral surface of the connecting portion between the nut shaft portion (4s) and the flange portion (4f) is connected by a stress concentration relaxation line.
  • the outer diameter of the screw shaft portion is preferably a standard dimension corresponding to the screw hole diameter of the nut, and the outer diameter of the bearing surface of the flange portion is the radial dimension (Ls) of the stress non-transmission space (1s).
  • the enlarged dimension is preferably 0.7 times or more the radial dimension (Ls) of the stress non-transmission space (1s), 0.8. It may be double or more, 0.9 times or more, 1.0 times or more, preferably 1.3 times or less, and may be 1.2 times or less, 1.1 times or less, 1.0 times or less. Further, the axial (maximum) dimension of the flange portion, that is, the dimension from the start point at which the radial dimension of the flange portion expands to the nut bearing surface is the radial dimension (Ls) of the stress non-transmission space (1s).
  • the dimension is preferably 0.5 times or more, 0.7 times or more, 0.8 times or more, 0.9 times the radial dimension (Ls) of the stress non-transmission space (1s). It may be double or more, 1.0 times or more, preferably 1.3 times or less, and may be 1.2 times or less, 1.1 times or less, 1.0 times or less.
  • the outer peripheral inclined portion of the flange portion (4f) of the nut (4) is the second stress non-transmission space (12s) of the washer (1) in the vertical cross section.
  • the shortest distance between the outer peripheral inclined portion of the flange portion (4f) and the corner portion (Bc) of the washer (1) is the radial dimension of the screw shaft portion (the outer peripheral dimension of the screw shaft portion). The difference between the screw and the inner diameter of the screw) is substantially the same, for example, 0.8 to 1.2 times and 0.9 to 1.1 times.
  • the surface (seat surface) of the nut (4) on the washer (1) side may be a flat surface.
  • the nut (4) having a flat seat surface is preferable because it is easily available and manufactured.
  • the screw shaft portion As long as it retains the strength of (4s) and does not need to transmit the fastening force, it may be formed as a space (recess).
  • the nut (4) comes into contact with the washer (1) on the flat surface on the washer (1) side, and the threaded portion of the nut (4) (including the first screw thread). ) Is not located below the washer (1) side flat surface (washer side).
  • the nut (4) does not need to form a notch or a recess (space) with respect to the normal shape, and when the nut (4) is a flange nut, the flange portion (4f) and the screw shaft portion (4s) In any of the above cases, it is not necessary to form a notch or recess (space) with respect to the normal shape of the nut (4), and it is preferable that there is no such notch or recess (space). Notches or recesses (spaces) may impair the strength of the nut.
  • the normal shape of the nut (4) is that if the screw shaft portion main body (polygonal portion including the screw shaft portion), the distance from the bolt hole (1h) to the outer periphery of the screw shaft portion main body is in the axial direction. It means that there is no notch or gap in the meat part, and if it is the flange part (4f), the distance from the bolt hole (1h) to the outer circumference of the screw shaft part main body is the corresponding distance of the screw shaft part main body. Expands in the axial direction to reach the seating surface (as described above, the distance from the bolt hole (1h) to the outer periphery of the screw shaft portion main body may be constant in the vicinity of the seating surface), and extra meat is added to the meat portion. It means that there is no notch or void.
  • a washer body (1b) having parallel first and second planes (1u, 1w) and the first and second planes (1b) penetrating the washer body (1b).
  • a washer (1) having a bolt hole (1h) extending in a direction perpendicular to 1u and 1w), wherein the washer (1) has an axis (z) and an axial direction of the bolt hole (1h).
  • the washer body (1b) has a stress non-transmission space (1s) that opens into the bolt hole (1h) and extends in the radial direction in a vertical cross section including the axis of the washer (1).
  • a washer (1) is provided in which the stress non-transmission space (1s) is a concentric annular shape centered on the axis (z) of the bolt hole (1h).
  • the second aspect of the present invention is an invention having an application development aspect of the first aspect, and the matters described in the first aspect can be applied as they are or modified to be applied to the second aspect. , Also adapts to the second aspect. Therefore, in particular, it is understood that the matters described about the washer in the first aspect and the matters concerning the relationship between the washer and the washer fastening structure also apply to the second aspect without any particular notice. Should be. On the contrary, it is understood that the matters described about the washer in the second aspect and the matters concerning the relationship between the washer and the washer fastening structure can be applied to the first aspect without any particular notice. Should be.
  • FIG. 1 and 5 show an example of a structure in which the object to be fastened (2) is fastened to the substrate (5) using a bolt (3), a nut (4), and a washer (1) as a vertical sectional view thereof.
  • FIG. 1 is an example of the prior art
  • FIG. 5 is an example of a fastening structure using the washer of the present invention.
  • the fastening direction of the bolt (3), the nut (4), the washer (1), the object to be fastened (2) and the substrate (5) is the axial direction of the bolt (3), and the fastening structure and the bolt ( 3), the axial direction common to the nut (4) and the washer (1).
  • the direction perpendicular to the axial direction is called the radial direction.
  • the radial bolt side (bolt hole side) is referred to as the inside, and the direction away from the bolt side is referred to as the outside.
  • Bolt-nut fastening is performed by tightening the female screw formed on the nut (4) against the male screw formed on the bolt (3). Therefore, basically, the screw of the bolt (3) is fastened. From the nut (4) to the washer (in the direction perpendicular to the contact surface between the nut (4) and the washer (1) and the contact surface between the washer (1) and the object to be fastened (2)) of the bolt (3). A tensile stress acts toward the side of 1) (see FIG. 2). At the same time, when the nut (4) is tightened against the bolt (3), a compressive stress acts on the screw of the nut (4) between the contact surface of the nut (4) and the washer (1).
  • the compressive stress acts between the position radially away from the screw axis of the washer (1) and the screw of the nut (4), it acts in a direction inclined with respect to the screw axis (see FIG. 3).
  • the intensity is represented by the vector density and length as well as the direction of the field line.
  • the compressive stress acts on the screw of the bolt (3) as a reaction force of the compressive stress acting on the screw of the nut (4). Therefore, a stress obtained by combining the above tensile stress and compressive stress acts on the screw of the bolt (3) (see FIG. 4).
  • * indicates a place that is easily destroyed.
  • FIG. 4 shows the result of synthesizing the tensile stress and the compressive stress of FIGS. 2 and 3, and shows the magnitude of the stress vector in grayscale (white represents the largest force).
  • the direction of stress can be understood by the position and orientation of the white part.
  • the first thread (mountain peak) and the second thread (mountain peak) of the bolt (3) are fastened and meshed with the screw of the nut (4). ⁇ ⁇ Corresponds to each.
  • the numerical value of the load sharing rate with nuts (the load sharing rate of bolts is also supported) is 35.6% for the first thread of fastening meshing, 20.6% for the second thread, 14.5% for the third thread, and 4 The threads are 11.0%, 5th 8.5%, 6th 5.9%, 7th 3.9%, and sharply toward the open side (higher-order side) 4o of the thread. It was confirmed that the load sharing was reduced.
  • the stress (tensile stress and compressive stress) applied to each thread by fastening is moved to the higher-order thread side (upward in FIGS. 1 to 4 and fastening force release side) 4 adopted as compared with the conventional product, and fastened. It is considered that if the stress applied to the first and second threads of the bolt (3), especially the first thread, can be reduced, the fatigue failure of the bolt (3) can be reduced and the fatigue life can be extended. ..
  • the washer (1) on the second aspect of the present invention is a washer having a structure that enables this.
  • FIG. 5 is a view showing a vertical cross section including an example bolt hole (1h) of the washer (1) on the second side surface of the present invention.
  • the washer body (1) of the washer (1) A stress non-transmission space (1s) is provided on the object to be fastened (2) side and the bolt hole (1h) side of 1b).
  • This stress non-transmission space (1s) has a concentric annular shape centered on the axis of the bolt hole (1h).
  • the compressive stress from the contact surface between the washer (1) and the object to be fastened (2) is the stress non-transmission space (1s). It acts between the contact surface between the washer (1) and the object to be fastened (2) and the screw of the nut (4) and the bolt (3) only in the portion where 1s) does not exist.
  • a part of the stress propagated in the axial direction (upper direction in the figure) of the bolt (3) in the portion where there is no stress non-transmission space (1s) is deflected toward the bolt (3) above the stress non-transmission space (1s).
  • the stress applied to the bolt (3) fastening mesh lower-order mountain valley bottom side can be reduced. It is possible.
  • the stress non-transmission space shown in FIG. 5 is an example (an example of aspect A) of the stress non-transmission space of the washer (1) on the second side surface of the present invention, and the washer (1) of the present invention has this structure. Not limited.
  • the stress non-transmission space (1s) is a space that opens in the bolt hole (1h) and extends in the radial direction in the vertical cross section including the axis of the washer (1), and is centered on the axis of the bolt hole (1h). It may be a concentric ring.
  • Stress non-transmission space The stress non-transmission space (1s) is opened in the bolt hole (1h) in the vertical cross section of the washer (1). Since the stress non-transmission space (1s) is opened in the bolt hole (1h), the axial transmission of the fastening force on the bolt hole (1h) side of the washer (1) is blocked, so that the stress non-transmission space is blocked. Since only the fastening force from the outer peripheral side of (1s) is transmitted to the bolt hole (1h) side and the fastening force has to wrap around from the outer peripheral side of the stress non-transmission space (1s), the bolt on the bolt hole (1h) side. The force applied to the lower-order mountain grain side of the fastening mesh of (3) is reduced.
  • the stress non-transmission space (1s) opens in the bolt hole (1h) in the vertical cross section of the washer (1), and further, the first plane (upper plane) (1u) on the nut (4) side of the washer body (1b). ), Or the second plane (lower plane) (1w) of the washer body (1b) on the object to be fastened (2) side, or the washer body (1w).
  • the shape may not be open to either the first plane (upper plane) (1u) or the second plane (lower plane) (1w) of 1b).
  • 5 to 7 are examples of the washer body (1b) opening on the first plane (upper plane) (1u) side. At least one stress non-transmission space, since the washer body (1b) must partially extend to the bolt hole (1h) for alignment (centering) to allow bolt alignment.
  • first plane (1s) is usually the first plane (upper plane) (1u) and the second plane of the washer body (1b) in the vertical cross section including the portion extending to the bolt hole (1h) of the washer (1).
  • Bottom plane A shape that does not open to one or both of (1w).
  • either the first plane (1u) or the second plane (1w) of the washer (1) can be on the top, but in the bolt / nut fastening structure, the nut side is on the top. Since it is convenient to think about it, the first plane will be referred to as an upper plane (1u) and the second plane will be referred to as a lower plane (1w) for convenience of explanation.
  • the washer (1) on the second side surface of the present invention can satisfy the requirements of the washer (1) on the second side surface of the present invention when one of the two planes is the first plane (upper plane). Just do it.
  • the stress non-transmission space (1s) is different from the conventional chamfering and deburring, at least in terms of purpose and dimensions, and in most cases in shape.
  • chamfering and deburring of corners on the surface of the washer body (1b) in contact with the bolt hole (1h) should be done in the axial direction to prevent interference such as the bolt neck R riding on the bolt (3) when it is placed under the neck.
  • the corners are ground or cut to the minimum allowable size, and the chamfering and deburring dimensions are made as small as possible as long as the purpose is achieved. Its dimensions are about 5% or less of the thickness T of the washer body 1b, particularly 4% or less, or 5% or less of the diameter of the bolt hole 1h, particularly 4% or less.
  • the chamfering or deburring shape is either cut with a straight line having an inclined corner or the corner is made into an arc shape in the vertical cross section of the washer (1) (axis line at the corner). Same shape in direction and radius).
  • the stress non-transmission space (1s) in the present invention cuts off the transmission of the fastening force between the bolt and the nut, and reduces the stress applied to the lower-order chamfer side of the bolt fastening engagement.
  • the dimensions for that purpose are substantially different (larger dimensions) from chamfering and deburring.
  • the shape of the stress non-transmission space (1s) is usually substantially different from chamfering and deburring.
  • the shape of the stress non-transmission space 1s is not the same shape in the axial direction and the radial direction at the corners like chamfering, but is a shape having a larger radial dimension than the axial direction. It is clear that the stress non-transmission space of the present invention is different from chamfering and deburring when looking at its shape and dimensions.
  • the washer (1) of the present invention has a function of "not damaging the mating surface (nut seat surface, surface of the object to be fastened), and avoiding interference with the bolt neck R when the bolt (3) is inserted" required for the conventional washer. Can be designed and manufactured with.
  • the stress non-transmission space (1s) is a concentric ring centered on the axis of the bolt hole (1h).
  • the stress non-transmission space (1s) is, for example, a three-dimensional space (concentric annular space) formed by rotating a space (1s) having a cross-sectional shape as shown in FIG. 5 by 360 degrees about an axis.
  • the concentric annular space may be displaced or fluctuated in shape (for example, axial dimension) within a range that does not impair the effect of the present invention. Even if there is displacement or fluctuation, the range or average value may be within the range defined by the present invention.
  • the washer body (1b) extends to the bolt hole (1h) may be a part of the washer body (1b). In that case, the washer body (1b)
  • the space formed by the portion where 1b) does not extend to the bolt hole (1h) can be continuous with the concentric annular stress non-transmission space.
  • the space continuous with the stress non-transmission space is a portion that does not transmit stress, but is not the stress non-transmission space (concentric annular space) defined in the present invention.
  • the fastening force basically acts in the axial direction, but the compressive stress from the contact surface of the washer (1) with the object to be fastened (2) is transmitted inside the nut (4) and is transmitted from the axial direction. It can be transmitted to the screw of the bolt (3) with a constant spread (inclination), and can wrap around from the outside of the stress non-transmission space (1s) to the bolt hole (1h) side.
  • the washer (1) of the present invention is used, the compressive stress between the washer (1) and the object to be fastened (2) is limited to the outside of the stress non-transmission space (1s) due to the presence of the stress non-transmission space (1s).
  • the radial dimension of the stress non-transmission space (1s) is set to an appropriate dimension or less, the stress applied to the low-order thread of the bolt can be reduced, and the outer diameter of the nut and washer does not need to be increased too much. preferable.
  • the radial dimension of the stress non-transmission space (1s) is from the position Ps, where Ps is the position farthest from the bolt hole (1h) of the stress non-transmission space (1s).
  • the distance L in the radial direction to the inner peripheral surface (1i) of the bolt hole parallel to the axis z or its extension line can be defined.
  • the washer (1) has a stress non-transmission space (11s) opened on the bolt hole (1h) side and the upper plane (1u) side of the washer body (1b). Can be done.
  • the position Ps farthest from the bolt hole (1h) in the first stress non-transmission space (11s) is the washer body (11s).
  • the distance in the radial direction from the position Pt in contact with the upper plane (1u) of 1b) to the extension line of the inner peripheral surface (1i) of the bolt hole parallel to the axis is defined as L.
  • the washer (1) has a second stress non-transmission space (12s) opened on the bolt hole (1h) side and the lower plane (1w) side of the washer body (1b). Can have.
  • the fourth boundary line (B4) of the washer body (1b) and the second stress non-transmission space (12s) in the radial direction from the bolt hole of the second stress non-transmission space (12s) of the fourth boundary line (B4).
  • the washer (1) on the second side surface of the present invention is, in one preferred embodiment, when the stress non-transmission space (1s) has the position Ps farthest in the radial direction from the axis z in the vertical cross section of the washer (1).
  • the radial distance L from the position Ps to the inner peripheral surface (1i) parallel to the axis of the bolt hole 1h or its extension line is 0.5p ⁇ L ⁇ 5.7p, more preferably 0.8p ⁇ L ⁇ 5.6p, 1.0p ⁇ L ⁇ 5.0p, still more preferably 1.5p ⁇ L ⁇ 4.5p, especially 2.0p ⁇ L ⁇ 4.0p, and further 2.5p ⁇ L ⁇ 3.5p (In the formula, the diameter of the bolt hole (1h) is R, and the units of R and p are mm.
  • R When R is 1.9 or less, p is 0.2 and When R is more than 1.9 and less than 2.4, p is 0.25. When R is more than 2.4 and 3.7 or less, p is 0.35. When R is more than 3.7 and 5.5 or less, p is 0.5. When R is more than 5.5 and 7.5 or less, p is 0.75. When R is more than 7.5 and 9.5 or less, p is 1.0. When R is more than 9.5 and 13 or less, p is 1.25. When R is more than 13 and 23 or less, p is 1.5. When R is more than 23 and less than 34, p is 2. When R is more than 34 and less than 40, p is 3. When R is more than 40 and 150 or less, p is 4. ) Meet.
  • This aspect is advantageous when the washer is combined with bolts and nuts having fine or coarse threads, and especially when combined with bolts and nuts having fine threads.
  • fine screws are preferably used for precision structural applications, and the problem of durability is more serious with fine screws, so improvement of the fastening structure when using fine screws is more sought after. Therefore, the effect of the washer in this embodiment is more remarkable when used together with the bolt and nut of the fine screw.
  • the washer of this aspect is also effective when used with bolts and nuts of coarse threads, and may be effective even in the case of coarse threads.
  • the washer (1) on the second aspect of the present invention can have an L in a range different from the above range in another preferred embodiment.
  • washers may be provided that are particularly advantageous when combined with coarse or coarse threaded bolts and nuts.
  • FIG. 5 shows a washer (1) which is a preferable example in the second aspect of the present invention, and a vertical cross-sectional view of a washer fastening structure using the washer (1).
  • (3) is a bolt
  • (4) is a nut
  • (1) is a washer
  • (2) is an object to be fastened
  • (5) is a substrate.
  • the washer (1) has a washer body (1b) and a bolt hole (1h) that penetrates the washer body (1b) and has an axis.
  • the washer (1) and the washer body (1b) have an axis and an axis direction z, and a radial direction r perpendicular to the axis z.
  • the washer body (1b) has two parallel planes, that is, an upper plane (1u) and a lower plane (1w), and an inner peripheral surface (1i) defining a bolt hole (1h) in the center and a bolt hole (1i). It has an outer peripheral surface (1 réelle) that is radially outside from 1h).
  • the bolt hole (1h) is a hole through which the bolt (3) is penetrated, and has a diameter R slightly larger than the bolt diameter according to the assumed bolt diameter.
  • the bolt hole diameter of a nut for a nominal M10 may be 11 mm.
  • the surface (inner peripheral surface) (1i) defining the diameter R of the bolt hole 1h is parallel to the axis in the vertical cross-sectional view including the axis as shown in FIG.
  • the shape of the cross section of the bolt hole (1h) is not limited, but is usually circular.
  • the bolt hole (1h) of the washer (1) has the outer diameter of the bolt (3).
  • the inner peripheral surface of the eaves portion 1p described later is composed of the inner peripheral surface (1i) of the bolt hole, but the inner peripheral surface (1i) of the eaves portion (1p) is a plan view (cross section).
  • the plan view it is not necessary to exist on the entire circumference of the circular bolt hole (1h), and it is sufficient that two or more protrusions are formed so that the bolt (3) can be positioned.
  • the space between the protrusions in the plan view is not a bolt hole in the second side surface of the present invention. In the plan view, the space between the bolt hole and its protrusion is continuous.
  • the planar shape of the bolt hole is not circular, but in such a case, the bolt hole is a virtual circular hole, and the washer body 1b has a virtual shape. Only the inner peripheral surface (1i) constituting the circular hole of the bolt hole is considered as the inner peripheral surface (1i) of the bolt hole.
  • the washer body (1b) has a stress non-transmission space (1s), and the stress non-transmission space (1s) is opened in a bolt hole (1h).
  • the stress non-transmission space (1s) is a space having a cross-sectional shape shown in FIGS. 6 and 7 (a), three-dimensionally, about the axis of the bolt hole (1h) of the washer (1) in the vertical cross-sectional view. Is a three-dimensional space (concentric ring) formed by rotating 360 degrees (see FIGS. 7 (b) and 7 (c)).
  • the compressive stress applied to the screw of the bolt (3) from the contact surface between the washer (1) and the nut (4) is a stress non-transmission space. Due to the presence of (1s), it is limited to the outer peripheral side of the stress non-transmission space (1s) and wraps around the bolt hole (1h) from the outer peripheral side of the stress non-transmission space (1s), but the compressive stress extends to the bolt hole side.
  • the maximum direction is an elevation angle (angle ⁇ ) of approximately 45 degrees with respect to the axis z from the position Ps, which is the end far from the bolt hole (1h) in the stress non-transmission space (1s).
  • the compressive stress transmitted to the bolt hole side at an angle of about 45 degrees or less with respect to the axis z depends on the size of the radial dimension L of the stress non-transmission space 1s, and the higher-order peaks (particularly the peaks) of the bolts. ), That is, it goes to the open side, and it is possible to reduce the load sharing ratio of the low-order thread of the bolt, especially the first thread. Further, when the radial dimension L of the stress non-transmission space (1s) is set to an appropriate dimension or less, the stress applied to the low-order thread is sufficiently reduced, and the outer diameter of the nut and washer is kept small. It is preferable because it can be used.
  • the distance L of the stress non-transmission space (1s) is 0.5p or more based on the value of p defined above. For example, 0.6p or more, 0.7p or more, 0.8p or more, 1. It may be 0p or more, 1.2p or more, 2.0p or more, 2.5p or more, 3p or more, and may be 5.7 or less, but for example, 5.0p or less, 4.0p or less, 3.5p or less. 0.6p ⁇ L ⁇ 5.6p, more preferably 0.8p ⁇ L ⁇ 5.6p, 1.0p ⁇ L ⁇ 5.0p, still more preferably 1.5p ⁇ L ⁇ 4.5p. In particular, it is preferable to satisfy 2.0p ⁇ L ⁇ 4.0p and further 2.5p ⁇ L ⁇ 3.5p.
  • FIG. 5 shows a washer (1) which is a preferable example of the aspect A in the second aspect of the present invention, and a vertical sectional view of a washer fastening structure using the washer (1).
  • (3) is a bolt
  • (4) is a nut
  • (1) is a washer
  • (2) is an object to be fastened
  • (5) is a substrate.
  • the washer (1) has a washer body (1b) and a bolt hole (1h) that penetrates the washer body (1b) and has an axis.
  • the washer (1) and the washer body (1b) have an axis and an axis direction z, and a radial direction r perpendicular to the axis z.
  • the washer body (1b) has a first stress non-transmission space (11s), and the first stress non-transmission space (11s) is opened in a bolt hole (1h). It is also open on the upper plane (1u). That is, the first stress non-transmission space (11s) is in contact with the extension line (B1) of the upper plane (1u) in the vertical sectional view and is below the extension line (B1).
  • the third boundary line (B3) between the first stress non-transmission space (11s) and the washer body (1b) is a stress such as an arc or an elliptical arc convex upward from the position Pt on the upper plane (1u).
  • the concentration relaxation curve extends to the position Ph of the inner peripheral surface (1i) (the surface defining the bolt hole (1h)) of the washer body (1b). Since the position Pt is on the upper plane (1u) of the washer body (1b) (the end of the upper plane (1u) and the boundary between the upper plane (1u) and the first stress non-transmission space (11s)), with line X of the elevation angle of 45 degrees with respect to the axis z is the position Ps in contact farthest from the bolt hole (1h) of the first stress non-transmitting space (11s), a straight line X is the washer body through the position P 1 (1b) It is also the position Pt that intersects the upper plane (1u).
  • the straight line X is said to "contact” the first stress non-transmission space (11s), but the straight line X is "the farthest position" from the bolt hole (1h) that "intersects” the first stress non-transmission space (11s). Means.
  • the first stress non-transmission space (11s) has a cross-sectional shape in contact with the upper plane (1u) (or an extension line thereof) of the washer body (1b) and below it in the vertical cross-sectional view, but three-dimensionally. Is a three-dimensional space (concentric annular shape) formed by rotating the cross-sectional space shown in FIGS. 6 and 7 (a) by 360 degrees around the axis of the bolt hole (1h) of the washer (1). ) (See FIGS. 7 (b) and 7 (c)).
  • the first stress non-transmission space (11s) is opened in the bolt hole (1h) in the vertical cross-sectional view of the washer (1). Since the first stress non-transmission space (11s) is opened in the bolt hole (1h), the axial transmission of the fastening force on the bolt hole side of the washer body (1b) is blocked, so that the bolt hole side The force applied to the lower ridges of the fastening mesh of a certain bolt is reduced.
  • the compressive stress applied to the screw of the bolt (3) from the contact surface between the washer (1) and the nut (4) is in the first stress non-transmission space (11s). Due to the presence, it is limited to the outer peripheral side of the first stress non-transmission space (11s) and wraps around the bolt hole (1h) from the outer peripheral side of the first stress non-transmission space (11s), but the compressive stress extends to the bolt hole side.
  • the maximum direction is an elevation angle (angle ⁇ ) of approximately 45 degrees with respect to the axis z from the position Ps, which is the end far from the bolt hole in the first stress non-transmission space (11s).
  • the compressive stress transmitted to the bolt hole side at an angle of about 45 degrees or less with respect to the axis z is a higher-order mountain of the bolt according to the magnitude of the radial dimension L of the first stress non-transmission space (11s). It is possible to reduce the load sharing ratio of the lower thread of the bolt, especially the first thread, by moving toward the grain (especially the peak), that is, the open side. Further, when the radial dimension L of the first stress non-transmission space (11s) is set to an appropriate dimension or less, the stress applied to the low-order thread is sufficiently reduced, and the outer diameter of the nut and washer is reduced. It is preferable because it can be suppressed.
  • the distance L of the first stress non-transmission space (11s) is 0.6p ⁇ L ⁇ 5.6p, more preferably 0.8p ⁇ L ⁇ 5.6p, 1.0p ⁇ L ⁇ 5.0p, still more preferably 1.5p ⁇ L ⁇ 4.5p, especially 2. 0p ⁇ L ⁇ 4.0p, and further 2.5p ⁇ L ⁇ 3.5p (In the formula, the radius of the bolt hole is R, the unit of R and p is mm, and R and p have the above-mentioned relationship.) It is preferable to satisfy.
  • the end of the washer body (1b) on the bolt hole (1h) side constitutes an inner peripheral surface (1i) at which the end of the washer body (1b) faces the bolt hole (1h), and the bolt (3) is centered.
  • the thickness of the end portion (lower side of the first stress non-transmission space (11s)) of the washer body (1b) may be reduced so as to enable the above.
  • the end of the washer body (1b) (the axial dimension of the inner peripheral surface (1i) may be 1 to 99% of the thickness T of the washer body (1b). For example, the end of the washer body (1b).
  • the minimum axial dimension (thickness) Th of the portion (inner peripheral surface (1i)) is preferably 0.1 times or more and 0.7 times or less the thickness T of the washer, and more preferably, Th is. 0.2T ⁇ Th ⁇ 0.6T, and more preferably 0.22T ⁇ Th ⁇ 0.5T.
  • the third boundary line (B3) of the washer body (1b) and the first stress non-transmission space (11s) is composed of a curved line or a combination of a curved line and a straight line, and is composed of a stress concentration relaxation curve without corners. It is preferably composed, and particularly preferably composed only of curves. Further, the connection point between the upper plane (1u) of the washer body (1b) and the third boundary line (B3) of the first stress non-transmission space (11s) is a place where stress for fastening is likely to be concentrated. It is particularly preferable that the stress concentration relaxation curve has no corners.
  • the stress concentration relaxation curve is not necessarily large at the connection point between the inner peripheral surface (1i) of the bolt hole of the washer body (1b) and the third boundary line (B3) of the first stress non-transmission space (11s). It does not have to be configured as.
  • the washer of aspect A of the second aspect of the present invention is the third boundary line between the washer body (1b) and the first stress non-transmission space (11s) in the longitudinal section of the washer (1).
  • the fastening force by the virtual nut is applied to the upper plane (1u) of the washer body (1b).
  • the lower plane (1u) is perpendicular to the upper plane (1u) from the position Pt in contact with the first stress non-transmission space (11s).
  • the stress distribution curve of the Mieses equivalent stress value at a predetermined ratio with respect to the reference is on the bolt hole 1h side with respect to the Mieses equivalent stress value applied in the direction.
  • This predetermined ratio may be 95%.
  • the predetermined ratio may be, for example, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or 5%. It is particularly preferable that the predetermined ratio is 20%, 10%, or 5%.
  • the Mises equivalent stress distribution is a technique for visualizing the state of force inside a ductile material that cannot be actually seen. It subdivides the inside of a substance, calculates a vector in three axial directions, and expresses it collectively. Therefore, the direction of the internal force and the magnitude of the force (stress) are expressed as a distribution. It is a method known in strength of materials, and a typical formula is as follows, and the Mises stress ⁇ Mises is expressed by the following formula using the principal stresses ⁇ 1 , ⁇ 2 , and ⁇ 3 .
  • FIG. 13 shows one vertical cross section. For example, the analysis of FIGS. 8 and 11 is performed at 1/360 degree, which is consistent with the sum of 360 degrees.
  • the stress applied to the washer (1) is never even, and is concentrated on the bolt hole side (inner circumference side of the nut) or at a considerably large rate (from various simulation results).
  • the load sharing on the outer peripheral side of the nut (4) and washer (1) is small (there are many black parts in the simulation). Therefore, even if it is considered that the nuts and washers on the inner diameter side are concentrated on the contact point Pt, it is appropriate to analyze and design in consideration of the safer side.
  • a fastening force is applied from the seat surface of the nut (4) to the contact surface (region on the outer diameter side of Pt) of the washer (1) at the time of fastening, and the nut seat is located at the position Pt of FIG. 11 (a).
  • the compressive force F from the surface is vertically applied, and compressive stress is generated in the washer from the position Pt.
  • the washer (1) is flat on both the upper and lower surfaces and has the same thickness on the entire surface, and the force applied to the washer is concentrated only on the position Pt. And the force F diffuses in the washer.
  • FIG. 11 (b) An example of visualizing the Mises equivalent stress distribution under the above assumption is shown in FIG. 11 (b) with a black and white gradation.
  • the maximum stress is directly below the position Pt, and the stress becomes weaker as the distance from the Pt increases.
  • FIG. 11A the flow of force is represented by a curved arrow schematically showing a force line.
  • six lines of 1 mb, 1 mc, 1 md, 1 me, 1 mf, and 1 mg are displayed from 1 ma in the center to the bolt hole side. The numbers are on one side only, but the stress distribution curves are contrasting on both sides.
  • 1 ma is a stress applied vertically downward from Pt, which is the maximum stress.
  • the relative magnitude of the stress represented by 1ma, 1mb, 1mc, 1md, 1me, 1mf, and 1mg based on the magnitude of the stress of 1ma is determined regardless of the magnitude of the fastening force of the washer. It can be arbitrarily selected at regular intervals or at non-constant intervals. In this example, there are 7 levels from 1 ma to the outside of 1 mg.
  • the black-and-white gradation of FIG. 11 (b) is displayed in nine stages, and does not directly correspond to the line of FIG.
  • the third boundary line of the first fastening force non-transmission space (11s) (11s). It is preferable that B3) does not exist, and the relative stress line may be obtained from the Mises equivalent stress distribution.
  • 1ma is a vertical line directly below the position Pt, is the line on the bolt hole side most in the upper plane (1u) of the washer (1), and is the maximum stress line.
  • 1 mb to 1 mg are stress lines smaller than 1 ma in order. Since 1 mg is the smallest stress line and the stress on the bolt hole side is smaller than this, the effect of the fastening force on the strength of the washer can be ignored. Therefore, if the third boundary line (B3) of the first fastening force non-transmission space (11s) exists in the region (broken line shaded portion) on the bolt hole side from 1 mg, the first fastening force non-transmission space (11s) is formed.
  • 1 mg is preferably, for example, 10%, particularly 5% of the stress at 1 ma.
  • this relative stress has different magnitudes of stress at the upper part (near Pt) of the curved arrow and at the lower part (near the arrow of the arrow in the figure).
  • the evaluation may be performed on the lower plane (1w) of the washer (that is, the surface in contact with the object to be fastened (2)).
  • the washer may be evaluated from the nut side plane to a specific depth.
  • Black (large stress) to gray to white (small stress) in FIG. 11B shows such a stress distribution. Even when the force is diffused, it often spreads to about 45 degrees in the tangential direction. At that time, if the stress strength (1 ma) directly under Pt is compared with the stress strength (for example, 1 mc) on the bolt hole side, 1 ma is larger than that in black and gray in FIG. 11 (b). It is expressed by. It can be seen that the black and dark gray (high stress) regions in FIG. 11B show a decrease in stress toward the bottom of the position Pt, which means that the applied force is applied in the lateral direction (screw shaft) inside the washer. Since it is also diffused in the radial direction), the stress is displayed to be relatively small compared to the vicinity of Pt.
  • the region where the third boundary line (B3) of the first fastening force non-transmission space (11s) should not exist is a bolt from the line 1ma directly below the position Pt. Although it is a small region on the hole side, the third boundary line (B3) of the first fastening force non-transmission space (11s) starting from the position Pt is, for example, larger than 0.01p and within 0.03p (p is defined earlier). It is important that the stress concentration relaxation curve is obtained in the vicinity of the position Pt up to the value obtained.).
  • the stress concentration transition curve is, for example, an arc or an elliptical arc.
  • the portion connected from the position Pt of the upper plane (1u) of the washer body (1b) to the third boundary line (B3) of the first fastening force non-transmission space (11s) is also one of the above arcs and ellipses. It is particularly desirable to construct it as a stress concentration relaxation curve for parts and other parts.
  • the fact that the third boundary line (B3) of the washer body (1b) is on the bolt hole (1h) side from the specific Mises equivalent stress distribution indicates that, for example, 1 mb, 1 mc of the curved arrow. It means that there is a third boundary line (B3) of the first stress non-transmission space (11s) only on the bolt hole side of any one of 1, 1md, 1me, 1mf, and 1mg.
  • the most preferable specific Mises equivalent stress distribution is a line 1 mg (the stress line having a relative stress of 5% described above)
  • the stress from the position Pt is on the region side on the right side of the third boundary line (B3). It is a region that has almost no effect, and the washer (1) does not deform or buckle even if a space is created.
  • the range shown by the dashed diagonal line in FIG. 11A is a range that is not affected by the stress from the position Pt, and the region of the first stress non-transmission space (11s) can be set only in that range. preferable. However, since it may be used within the range of stress due to the component configuration, in that case, the vicinity of the position Pt starts with a stress concentration relaxation curve, resembling the shape of the curved arrow in FIG. 11 (a).
  • the third boundary line (B3) has a shape that goes down to the lower plane side, but the third boundary line (B3) may be provided on the bolt hole side from 1 ma and may be provided on the outer peripheral side from 1 mg. Good.
  • FIG. 11A is a range that is not affected by the stress from the position Pt, and the region of the first stress non-transmission space (11s) can be set only in that range. preferable. However, since it may be used within the range of stress due to the component configuration, in that case, the vicinity of the position Pt starts with
  • the third boundary line (B3) is on the bolt hole (1h) side from the position Pt and the stress distribution line equivalent to Mieses 1 mg, starts with an upwardly convex curve, and inflections in the middle and downwards.
  • the position Ph is reached as a convex curve, but in particular, the portion connected from the position Pt on the upper plane (1u) of the washer body (1b) to the third boundary line (B3) is also configured as a stress concentration relaxation curve.
  • It may be on the bolt hole side from 1 ma, and more preferably on the bolt hole side of 1 mb, the bolt hole side of 1 mc, the bolt hole side of 1 md, the bolt hole side of 1 me, and the bolt hole side of 1 mf.
  • the boundary line B3 should not be a vertical line such as 1 ma.
  • the method of obtaining the Mises equivalent stress distribution is known as described above. The Mises equivalent stress changes depending on the magnitude of the fastening force, but the above relative stress magnitude distribution does not change.
  • the force from the nut corresponding to the stress distribution is applied to the range of the Mises equivalent stress distribution shown in FIG. 11, and the compressive stress is acting inside the washer.
  • the third boundary line (B3) of the washer leaves Pt and immediately enters the inside of the washer, and that it enters between the line 1 mb and the line 1 mc and has a line that goes down vertically as it is.
  • the third boundary line B3 passes through a place where there is a compressive force vector directed from Pt toward the bolt hole side.
  • the part between the stress field lines 1 mb and 1 mc near Pt faces the bolt hole side.
  • the vector is working great. This vector continues to be given by the load F from Pt.
  • a third boundary line (B3) in this range a force derived from the load F is applied from the inside of the washer (1) to the curve created by the third boundary line B3.
  • the stress magnitude is indicated on the third boundary line (B3).
  • Aspect A of the second aspect is, in one preferred embodiment, subject to a thickness limitation on the shape of the third boundary (B3) forming the first fastening force non-transmission space (11s) of the washer (1).
  • the restrictions are: i) Within a certain thickness T, the third boundary line (B3) has a surface on the bolt hole side that has a length that allows centering with the shaft of the bolt, except that the outermost part of the washer.
  • the washer's first fastening force non-transmission space (11s) may be on one or both sides, iii) The washer's first fastening force non-transmission space (11s)
  • the thickness of the washer member reduced by the depth is in the range of 1% to 99% of the washer thickness T.
  • the point Pt in contact with the nut bearing surface starts from the reference point Po and goes toward the outer periphery. It must be in the range of 0.5p or more and 6p or less (0.5p ⁇ L ⁇ 6p), v)
  • the boundary line B3 that creates the first fastening force non-transmission space (11s) of the washer is stressed by the stress distribution equivalent to Mieses.
  • the boundary line B3 should be in contact with the nut seating surface with an edgeless stress concentration relaxation curve
  • the contact between the nut seating surface and washer should be on the outer peripheral side of the position Pt as the boundary. It is preferable that the first fastening force non-transmission space 11s of the washer of the aspect A satisfies these conditions as much as possible.
  • the distance L between Pt and P 0 is in the range of 0.5 p or more and 6 p or less (0.5 p ⁇ L ⁇ 6 p) toward the outer peripheral side starting from the reference point P 0 , and is preferably 1 p ⁇ L. It is in the range of ⁇ 5p, and more preferably 2p ⁇ L ⁇ 4p.
  • FIG. 12A is an example in which only a part of the ellipse from the position Pt has a third boundary line (B3) reaching the position Ph.
  • the first stress non-transmission space (11s) is located on both the upper and lower planes and has a vertically symmetrical shape. This is an example of a boundary line B3 that approaches the plane of the washer by a downwardly convex line, has an inflection point again, and reaches the position Ph by a horizontal straight line.
  • FIG. 12A is an example in which only a part of the ellipse from the position Pt has a third boundary line (B3) reaching the position Ph.
  • the first stress non-transmission space (11s) is located on both the upper and lower planes and has a vertically symmetrical shape. This is an example of a boundary line B3 that approaches the plane of the washer by a downwardly convex line, has an inflection point again, and reaches the position Ph by a horizontal straight line.
  • FIG. 12C is an example of a shape in which the first stress non-transmission space (11s) is located on both the upper and lower planes and reaches Ph by the third boundary line (B3) which is vertically asymmetrical.
  • FIG. 12D has a first stress non-transmission space (11s) only on the upper plane, starts with a part of an ellipse, enters a part of an arc in the opposite direction in the middle, and finally reaches the position Ph in a straight line.
  • This is an example in which the first stress non-transmission space (11s) is formed by the boundary line (B3), and each line is connected by a curve.
  • the position Ps farthest in the radial direction from the bolt hole (1h) in the first stress non-transmission space (11s) is the first stress non-transmission space (11s) in the upper plane (1u) of the washer. This is an example in which the position is farther from the bolt hole (1h) than the position Pt forming the boundary point with.
  • 1 m is a Mises equivalent stress distribution curve.
  • the first stress non-transmission space (11s) created by such a third boundary line (B3) there is an advantage that the amount of deformation and wall thinning is reduced when the space (11s) is produced by cutting or pressing. There is. Further, in such a case, since the first stress non-transmission space (11s) can be set on both sides of the washer, there is an advantage that it is not necessary to distinguish the front and back when using the washer. Further, the washer of the aspect A is not limited to the modification shown in FIG. Since the washer is centered with the bolt, it is desirable that the axial dimension of the inner peripheral surface of the bolt hole is longer than p (p is a value defined above).
  • the contact surface dimension of p or more is not limited to the dimension of one cross section, but may be a shape and a dimension for centering using a plurality of locations in the axial direction or the circumferential direction of the inner peripheral surface of the bolt hole. If the washer is centered with the bolt on the outer peripheral side of the washer, the bolt hole size indicates the Pt position and Mises stress distribution. If there is a third boundary line (B3) on the bolt hole side of the washer from at least 1 mb. Often, it is possible to widen the bolt holes of the washer and reduce the weight of the widened part.
  • the contact surface of the nut (4) and the object to be fastened (2) come into contact with each other.
  • the position Pt is often about the same distance on both sides, but in this case, the distribution of the stress equivalent to Mieses generated in the washer (1) is compressed because the spread from the nut bearing surface to the bolt hole side of the washer is small. It is desirable that the washer under stress has higher hardness and strength so as not to cause buckling. The choice of washer strength needs to be factored in at design time.
  • the points where the object to be fastened (2) and the washer (1) are also formed so as to be in contact with each other at the tangent line of the stress concentration relaxation curve, and the corners are on the bolt hole side and the outer peripheral side so as not to cause unnecessary buckling. Regardless of, it is desirable to attach a part of the circle or ellipse of the stress concentration relaxation structure.
  • FIG. 8 shows the stress status shown by the Mises equivalent stress distribution by performing FEM analysis on the washer of aspect A with the same dimensional configuration as that of FIG. 4 (conventional washer). It can be seen that the white color (high stress) is diagonally present at the position Pt, the compressive stress is large, and the thread is oriented in the fourth direction. Light gray (slightly large stress) spreads, and flange nut screws are applied to the 2nd to 5th threads. Looking at the bolt side, white (high stress) is on the first and second threads of the bolt screw, but the area is small. Light gray is the third thread of the screw, and dark gray (slightly small stress) extends widely to the end of the bolt.
  • FIG. 9 shows the results obtained by FEM analysis when fastened with the washer structure of aspect A shown in FIG. 6 and when fastened with the washer having the conventional structure shown in FIG. 1, and the results obtained by FEM analysis are shown in FIG. 9A for each thread.
  • the load sharing ratios are compared and shown in a list, and FIG. 9B shows the comparison of the load sharing ratios in a bar graph.
  • the load sharing ratio at the first thread of fastening mesh is 35.6% in the case of the conventional structural washer, whereas it is absolutely 30.2% in the model of aspect A (example of FIG. 6). The value is reduced by 5.4 points, and the relative value is reduced by about 15%.
  • Ls is the distance from the point at right angles to the axial extension line (4e) of the bottom of the nut screw valley to the position Ps (Pt). Further, the distance from the inner peripheral surface (1i) of the bolt hole of the washer (1) to the position Ps (Pt) is L. L is shorter than Ls by the length of the gap with the bolt hole. This gap length is the gap length of the bolt hole with respect to the bolt, and is typically 0.35 to 0.65 times the screw pitch p of the nut to be used, and is set to 0.4 p here. ..
  • the left figure of FIG. 10 shows the relationship between the change in the distance L (L / p) and the load sharing ratio of the first mountain of meshing in the aspect A of the first aspect of the present invention.
  • the value of L / p on the horizontal axis is shown above the graph in the figure.
  • the right figure of FIG. 10 summarizes the effects when the washer distance L of the aspect A is changed.
  • the upper right figure of FIG. 10 is the Mises equivalent stress distribution diagram of the washer fastening of the conventional structure of FIG.
  • the shape of the first stress non-transmission space (11s) is the same in depth Lh from Po to Ph of the inner peripheral surface of the bolt hole (1i), and the distance Ls in model 3 is the same as that in model 2. Is a shape that is longer in the radial direction.
  • the load sharing ratio is from 35.6% to 32.8%, 30.2%, 29.1%, 28.7%.
  • the stress index b 4
  • the Nf and lifetime are about 1.39 times, about 1.92 times, about 2.22 times, about 2.33 times, about 2. It is expected to increase by 56 times.
  • FIGS. 13 to 15 show an example of the washer (1) of the second aspect aspect B of the present invention. It is a vertical cross-sectional view except for FIGS. 15 (b) and 15 (c). 15 (b) and 15 (c) are perspective views.
  • the washer (1) has a washer body (1b) and a bolt hole (1h) that penetrates the washer body (1b) and has an axis.
  • the washer (1) and the washer body (1b) have an axis and an axis direction z, and a radial direction r perpendicular to the axis z.
  • the washer body (1b) has two parallel planes (also referred to as an upper plane (1u) and a lower plane (1w) for convenience in this embodiment), and an inner peripheral surface defining a bolt hole (1h) in the center. It has (1i) and an outer peripheral surface (1 réelle) that is radially outside the bolt hole (1h).
  • the bolt hole (1h) is a hole through which a bolt is penetrated, and has a diameter R slightly larger than the bolt diameter according to the assumed bolt diameter.
  • the bolt hole diameter of a nut for a nominal M10 may be 11 mm.
  • the surface (inner peripheral surface (1i)) defining the diameter R of the bolt hole (1h) is parallel to the axis in the vertical cross-sectional view including the axis as shown in FIGS. 13 to 15.
  • the shape of the cross section of the bolt hole (1h) is not limited, but is usually circular.
  • the bolt hole (1h) of the washer (1) is predetermined with respect to the outer diameter of the bolt in order to stably arrange the washer (1) with respect to the bolt by penetrating the bolt through the bolt hole (1h). It is preferably circular in size.
  • the inner peripheral surface of the eaves portion (1p) described later is composed of the inner peripheral surface (1i) of the bolt hole, but the inner peripheral surface (1i) of the eaves portion (1p) is a plan view.
  • the bolt can be positioned with respect to the bolt by forming two or more protrusions.
  • the space between the protrusions in the plan view is not a bolt hole in the present invention. In the plan view, the space between the bolt hole and its protrusion is continuous.
  • the planar shape of the bolt hole is not circular, but in such a case, the bolt hole is a virtual circular hole of the washer body (1b). Only the inner peripheral surface (1i) constituting the virtual circular hole is considered as the inner peripheral surface (1i) of the bolt hole.
  • the washer body (1b) has a second stress non-transmission space (12s) that opens into the bolt hole (1h), and the second stress non-transmission space (12s) is a lower plane. It is also open to (1w).
  • the boundary line between the second stress non-transmission space (12s) and the washer body (1b) rises almost vertically from the lower plane (1w) (rising edge (Br)) and passes through the corner of a curve close to an arc. It approaches the upper plane (1u), extends to the inner peripheral surface (1i) (the surface defining the bolt hole (1h)) of the washer body (1b), and extends above the second stress non-transmission space (12s).
  • Part (1p) is formed.
  • the rising portion (Br) rising substantially vertically from the lower plane (1w) may be within an angle of ⁇ 20 degrees with respect to the vertical direction in consideration of manufacturing accuracy.
  • the second stress non-transmission space (12s) has an upwardly convex cross-sectional shape shown in FIGS. 13 to 15 in the vertical cross-sectional view, but three-dimensionally, the axis of the bolt hole (1h) of the washer (1). It is a concentric ring centered on (see FIGS. 15 (b) and 15 (c)). That is, the second stress non-transmission space (12s) is a three-dimensional space (concentric annular space) formed by rotating the cross-sectional space shown in FIGS. 13 to 15 by 360 degrees around the axis.
  • the second stress non-transmission space (12s) is opened in the bolt hole (1h) in the vertical cross-sectional view of the washer. Since the second stress non-transmission space (12s) is opened in the bolt hole (1h), the axial transmission of the fastening force on the bolt hole side of the washer body (1b) is blocked, so that the bolt hole side The force applied to the lower ridges of the fastening mesh of a certain bolt is reduced.
  • the compressive stress from the contact surface between the washer (1) and the nut (4) to the threaded portion of the bolt (3) is due to the presence of the second stress non-transmission space (12s). It is limited to the outside of the second stress non-transmission space (12s), and as a result of wrapping around from the outside of the second stress non-transmission space (12s) to the bolt hole side, the direction in which the compressive stress extends to the bolt hole side is the second. It is a region having an elevation angle (angle ⁇ ) of about 45 degrees or less with respect to the axis z from the position Ps farthest in the radial direction from the bolt hole in the stress non-transmission space (12s).
  • the compressive stress that bends toward the bolt hole side at an angle of about 45 degrees or less with respect to this axis z is applied to the bolt fastening meshing low-order peak by moving toward the open side of the bolt's higher-order peak (especially the peak).
  • the radial dimension of the second stress non-transmission space (12s) is set to an appropriate dimension or less, the outer diameter dimension of the nut and washer can be kept small while sufficiently reducing the stress applied to the low-order thread. It is preferable because it can be done.
  • the distance L in the direction is 0.5p ⁇ L ⁇ 5.6p, more preferably 0.7p ⁇ L ⁇ 5.6p, 1.0p ⁇ L ⁇ 5.0p, still more preferably 1.5p ⁇ L ⁇ 4.5p, especially 2.
  • the washer body (1b) has an eaves portion (1p) on the upper side of the second stress non-transmission space (12s).
  • the eaves portion (1p) is a member for centering with the bolt 3 with respect to the bolt hole (1h), and the tip of the eaves portion (1p) may form the inner peripheral surface of the bolt hole (1h). ..
  • the eaves (1p) forming the inner peripheral surface (1i) of the bolt hole (1h) do not necessarily exist on the entire circumference of the bolt hole (1h) in the plan view of the washer body (1b), but all of them. It is preferable to define a circular bolt hole (1h) existing on the circumference.
  • the vertical thickness of FIGS. 13 to 15 may be as small as long as the strength of the eaves (1p) is maintained, and the smaller the thickness, the smaller the stress transmission. It is preferable because the contribution to is small.
  • the minimum thickness (Th) of the eaves portion (1p) is 0.1 times or more and 0.7 times or less the thickness T of the washer. More preferably, Th is 0.2T ⁇ Th ⁇ 0.6T, and even more preferably 0.22T ⁇ Th ⁇ 0.5T.
  • this eaves (1p) can be partially reduced, and if the shape is the thinnest on the way to the inner peripheral surface of the bolt hole through the corner, centering with the bolt on the innermost diameter side It is possible to secure the length of the inner peripheral surface (1i) that can be easily performed.
  • the fourth boundary line (B4) between the washer body (1b) and the second stress non-transmission space (12s) is approximately the same as the lower plane (1w) of the washer body (1b). It has a corner portion (Bc) that connects a rising portion (Br) that rises vertically and a portion that defines an eaves portion (1p) facing a bolt hole (1h).
  • the corner portion (Bc) is not limited, but in the vertical cross-sectional view of FIGS. 13 to 15, from the position where the boundary line is in contact with a straight line forming 20 to 25 degrees, particularly 25 degrees with respect to the axis z.
  • a position (P) where a straight line having an elevation angle ⁇ of 45 degrees with respect to the axis z is in contact with the boundary line, which is a portion up to a position tangent to a straight line forming 65 to 70 degrees with respect to the axis z, particularly 65 degrees.
  • the corner portion (Bc) may be composed of, for example, a straight line having an elevation angle of about 40 to 50 degrees, particularly about 45 degrees. In that case, the connecting portion between the corner portion (Bc) and the rising portion (Br), It is preferable that the connecting portion between the corner portion (Bc) and the eaves portion (1p) is joined by a curved line so as not to form a corner. Further, the corner portion (Bc) may be formed by an arc, an elliptical arc, or a shape close thereto. The area from the corner portion (Bc) to the inner peripheral surface of the bolt hole (1i) is the inner peripheral end portion (Be) of the bolt hole.
  • the fourth boundary line (B4) between the washer body (1b) and the second stress non-transmission space (12s) is the lower plane of the washer body (1b).
  • the inner peripheral surface of the bolt hole (1i) may be reached by the inner peripheral end portion (Be) of the hole.
  • Such a fourth boundary line (B4) is a stress concentration relaxation curve except for the connection point with the lower plane (1w) and the inner peripheral surface of the bolt hole (1i), and is a second stress non-transmission space having this shape (1i). 12s) is easy to form. Further, when the position P where the straight line having an elevation angle of 45 degrees with respect to the axis is in contact with the corner portion (Bc) is close to the upper plane (1u), the compressive stress transmitted from the object to be fastened (2) to the screw is not transmitted as the second stress. The position around the outside of the space (12s) has an effect of being farther from the inner peripheral surface (1i) of the bolt hole, which is preferable.
  • the position P where the corner portion (Bc) is in contact with a straight line having an elevation angle of 45 degrees with respect to the axis is located at an axial distance of 1/2 or more of the thickness T of the washer (1) from the lower plane (1w) of the washer body (1b). It is preferably less than or equal to the length of one pitch of the screw from the position P3 (Ps) of the starting point of the rising portion (Br) on the lower plane (1w) of the washer body (1b) toward the inner peripheral surface (1i) of the bolt hole. It is preferable to have.
  • the rising portion (Br) (from the lower plane (1w) to the position where a straight line having an elevation angle of 20 to 25 degrees with respect to the axis touches the fourth boundary line (B4)) is not limited, but is 1 of the thickness T of the washer (1). It is preferable to have an axial length of / 4 to 1/3 or more.
  • the end of the inner circumference of the bolt hole (Be) (from the position where the straight line with an elevation angle of 65 to 70 degrees with respect to the axis touches the fourth boundary line (B4) to the inner peripheral surface of the bolt hole (1i)) is the connection point with the corner (Bc).
  • the shape is such that the elevation angle formed by the tangent line with respect to the axis gradually increases from the bolt hole inner peripheral surface (1i), and the maximum elevation angle is preferably 90 degrees or less.
  • the minimum thickness of the eaves (1p) formed above the bolt hole inner peripheral end (Be) (thickness t of the bolt hole inner peripheral surface (1i) in FIG. 14) is the thickness T of the washer (1). It is preferably in the range of 3 to 20%, more preferably 5 to 15%.
  • the inner peripheral end portion (Be) of the bolt hole may have various deformations as shown in FIGS. 19 and 20, and further, the inner peripheral end portion (Be) of the bolt hole does not exist and is in the middle of the corner portion (Bc). Alternatively, the end may be a connection point with the inner peripheral surface (1i) of the bolt hole.
  • FIG. 16 shows a Mises equivalent stress distribution diagram.
  • the Mises equivalent stress is larger as the color is whiter and smaller as the color is blacker.
  • Gray has an intermediate size, and the black part indicates that the stress is smaller than that of white. Comparing FIG. 16 with FIG. 4 of the washer having the conventional structure, it can be seen that the range and position of the large stress of white are clearly different.
  • the range of light gray and dark gray extends to the fifth thread, and the black (small stress) portion becomes smaller.
  • FIG. 16 shows that the stress distribution shows that the stress is diffused after the third thread.
  • the large Mises equivalent stress extends from the corner of the concave space mainly at an elevation angle of 45 degrees or a little smaller than the screw axis direction. It can be seen that there are white and gray parts representing a large Mises equivalent stress in the subsequent (5th mountain). In this way, if the destination where the Mises equivalent stress, which is larger than when there is no recessed space, goes to the third and subsequent threads of the nut screw, the stress load sharing ratio of the first thread is set, and when there is no recessed space. Can be reduced compared to.
  • 17 (a) and 17 (b) are bar graphs comparing the load sharing ratio and the load sharing ratio of each thread of the washer of aspect B and the washer of the conventional structure obtained by FEM analysis.
  • the distance Ls is set to 2.21 times p (1.25 mm).
  • the load sharing rate of the first thread of fastening engagement is 32.3%, which is 3.3 points in absolute value and 9.3 in relative ratio compared to the same load sharing rate of 35.6% for the washer of the conventional structure. It has been shown to be reduced by%.
  • the horizontal axis is L / p (since the pitch p is the same, it is equivalent to the case where the distance L is changed), and the load sharing ratio of the first meshing peak is set.
  • the shape of the second stress non-transmission space (12s) is almost the same as the shape of the rising portion and the corner portion, and in the model 3, the eaves portion (1p) is different in the radial direction as compared with the model 2. It has a long shape.
  • the white part with high stress extends from the first thread to the higher-order thread side from the upper right figure to the middle right figure and the lower right figure. .. From these figures, the load sharing ratio of the first thread of the bolt screw at each black spot position is 35.6% in the upper right figure (conventional washer), 32.3% in the middle right figure, and 30.9% in the lower right figure. %Met.
  • the load sharing ratio of the first thread of the screw decreases substantially linearly as the distance L (L / p) increases, and the load sharing ratio of the first thread of the bolt screw decreases as the distance L (L / p) increases.
  • the absolute value decreased from 35.6% to 30.9% by 4.7 points, and the relative ratio decreased by about 13%.
  • the load sharing ratio is from 35.6% to 34.5%, 32.3%, 30.9%, 30.3.
  • the stress index b 4
  • the Nf and lifetime are about 1.12 times, about 1.45 times, about 1.75 times, about 1.92 times, and about 2. It is expected to increase by 13.13 times.
  • FIG. 19 shows a schematic diagram of a modified example of the second stress non-transmission space (12s).
  • B4 is a boundary line between the washer body (1b) and the second stress non-transmission space (12s).
  • FIG. 19A is an example in which the axial length (t) of the bolt hole inner peripheral surface (1i) is longer than the minimum thickness (Th) of the eaves portion (1p).
  • FIG. 19B shows an example in which a stress concentration relaxation curve structure is attached to a portion from the contact position between the object to be fastened and the washer (1) to the rising portion (Br), and the distance L in this case is shown.
  • FIG. 19 (c) It is on the outer peripheral side in the radial direction from the rising portion (Br) as in.
  • a second stress non-transmission space (12 s) that is convex from the inner peripheral side of the bolt hole to the outer peripheral side is provided in the middle of the thickness of the washer body, and the second stress non-transmission space (12 s) is provided.
  • FIG. 19C is an example in which two washers of FIG. 19B are attached facing each other.
  • the thread load sharing ratio of the first meshing thread can be increased. It can be reduced. Further, in this example, the upper and lower planes of the washer are the same, so that there is no misuse during use.
  • -Fig. 19 (d) shows a shape that takes into consideration the centering of the washer, and shows a method of increasing the length t of the inner peripheral surface of the bolt hole (see the shape on the bolt hole side) and a ring shape on the nut side on the outer peripheral side.
  • a modified example of a method of providing several protrusions and using the outer periphery of the nut to align the center with the bolt is shown. In the example of FIG.
  • the diameter of the bolt hole may be larger than the expected diameter of the bolt. .. In that case, it is used for a bolt having a screw with a pitch smaller than the value of p based on the definition in the inequality 0.5p ⁇ L ⁇ 5.6p based on the diameter R of the bolt hole in the example of FIG. 19 (d).
  • the above inequality is satisfied, the effect of reducing the load sharing ratio of the first thread of the bolt screw can be obtained.
  • the corner portion (Bc) of the boundary line (B4) of the second stress non-transmission space (12s) is composed of a straight line
  • both the rising portion (Br) and the inner peripheral end portion (Be) of the bolt hole are composed of a straight line.
  • the connecting portion between the corner portion (Bc), the rising portion (Br), and the inner peripheral end portion (Be) of the bolt hole is formed by a curved line.
  • the washer (1) on the second side surface of the present invention has two planes, that is, the first plane and the second plane (1u, 1w), but the bolt (3) and the nut (4) are used to fasten the object (2).
  • the washer on the second side surface is aspect A or aspect B is aspect A or aspect when one of the two planes is considered as the first plane (1u) (nut side, upper plane).
  • the requirement of B may be satisfied. Therefore, one washer may be a washer of aspect A when one plane is considered as the first plane (1u), and a washer of aspect A when the other plane is considered as the first plane (1u). it can.
  • the washer can be used as the washer of the aspect A regardless of which plane is used as the upper plane.
  • one washer can be a washer of aspect A when one plane is considered as a first plane (1u), and a washer of aspect B when the other plane is considered as a first plane (1u).
  • a washer that satisfies the requirements of aspect A can often be used as it is as a washer of aspect B by turning over the upper and lower planes.
  • the washer satisfying the requirement of the aspect B may be used as the washer of the aspect A by turning over the upper and lower planes, but in order to use it as the washer of the aspect A, the portion connecting the rising portion and the lower surface is stress-free. It is preferably configured as a concentrated curve.
  • one washer has two stress non-transmission spaces (1s), and the two stress non-transmission spaces (1s) satisfy the requirements of aspect A and the requirements of aspect B, respectively.
  • the washer is both the washer of the aspect A and the washer of the aspect B when one plane is used as the upper plane, but the washer has a substantially large effect of reducing the burden on the first mountain when used. It is thought that it acts as a washer.
  • the washer of the second aspect of the present invention is manufactured with the intention of being used as either aspect A or aspect B, even if the requirements of aspects A and B are met at the same time. It goes without saying that it is preferable to use it in the intended manner.
  • the thickness of the washer (1) of the present invention (axial dimension between the upper and lower planes) is 0.1 with respect to the bolt hole diameter R as the thickness T in the washer main body portion in which the stress non-transmission space is not formed. It may be double or more, 0.2 times or more, further 0.5 times or more, and may be 20 times or less, 10 times or less, and further 1.0 times or less.
  • the thickness (T) is 0.1 times or more the inner diameter of the bolt hole, preferably 0.2 times or more and 2.0 times or less the diameter of the bolt hole, and more preferably. May be 0.3 times or more and 1.5 times or less the bolt hole diameter.
  • the outer peripheral surface of the washer (1) of the present invention is the contact surface (upper plane) of the washer (1) with the nut (4) and the object to be fastened (2) of the washer (1), referring to FIG. It is preferable that the contact surface (lower plane) has a sufficient area for fastening the object to be fastened (2) from the nut (4) and the washer (1).
  • the area for fastening the object to be fastened (2) with the nut (4) and the washer (1) may be the same as that in the conventional washer having no stress non-transmission space (1s).
  • the outer peripheral surface of the washer (1) in the conventional washer may have a size having an inscribed circle of about twice the bolt hole diameter (for example, within 2R ⁇ 10%).
  • the bolt hole diameter R is the diameter of the center hole defined by the inner peripheral surface of the washer body (the same applies to other parts in the present disclosure).
  • the outer peripheral surface of the washer of the present invention has a diameter of a circle inscribed in the outer peripheral surface of the upper plane of the washer in the plan view of the upper plane of the washer body (1b), which is 2 of the bolt hole diameter.
  • the size may be greater than or equal to the sum of the double (or within ⁇ 10% of that; same as above) and the distance L at the position Ps from the inner peripheral surface of the bolt hole.
  • D o nR + L (n ⁇ 1.8, more n ⁇ 1.9, n ⁇ 2.0, n ⁇ 2.2) may be.
  • the outer peripheral dimension on the lower plane 1w side is larger than the outer peripheral dimension on the upper plane 1u side of the washer body, so that the upper plane 1u side of the washer body is shown in FIGS.
  • inclined cutting for example, an elevation angle of 30 to 60 degrees with respect to the axis line, particularly about 40 to 50 degrees may be performed.
  • the outer diameter of the washer is 1.4 times or more and 4 times or less of the bolt hole diameter, preferably 1.5 times or more and 3.5 times or less of the bolt hole diameter, and more preferably bolts.
  • the hole diameter may be 1.7 times or more and 2.8 times or less.
  • the outer circumference of the washer body (1b) may be larger than the outer circumference of the upper plane (1u) in contact with the nut.
  • the washer body (1b) may have a connecting portion between the outer circumference (1 réelle) and the upper plane (1u) cut at an elevation angle of, for example, 30 to 60 degrees, and further 40 to 50 degrees.
  • the size of the notch portion (1d) is the dimension in the thickness direction of the washer body (1b), and may be half or less, further one-third or less of the thickness (T) of the washer body (1b). ..
  • the washer (1) of the present invention is preferably a solid body that does not form a space other than the stress non-transmission space in the washer main body (1b).
  • a space other than the stress non-transmission space may be provided as long as the strength and fastening force of the washer of the present invention are not impaired.
  • the washer (1) of the present invention can chamfer the corners, and it is particularly preferable to chamfer with a curved line. Since the chamfering dimension is small, when considering the shape and dimensions of the washer body and the stress non-transmission space, the chamfering may be ignored or the chamfered portion may be excluded.
  • Hard resin for example, having a hardness of Vickers hardness Hv70 or more, and further Hv100 or more
  • Hv70 or more a hardness of Vickers hardness Hv70 or more, and further Hv100 or more
  • the selection of material and strength can be decided by the selection by the engineer on the user side.
  • the washer (1) of the present invention can be subjected to surface treatment having effects such as rust prevention, decoration, slidability improvement, and identification, which have been conventionally required for washers.
  • one type such as metal plating, polymer coating, fluororesin coating, coating of DLC, TiN, CrN, BN by plasma coating treatment such as PVD, CVD, manganese phosphate chemical conversion treatment, alumite, electrolytic polishing, etc. It can be selected and used from two or more combinations.
  • the washer (1) can be polished to improve the surface roughness in the previous step in order to secure the slidability with the nut (4).
  • the part of the washer surface that comes into contact with the nut bearing surface is surface-treated with a small frictional resistance and a stable friction coefficient to improve the efficiency of converting the nut tightening torque into axial force, and the shaft due to friction variation.
  • the force generation fluctuation becomes small.
  • the friction coefficient of many metals is about 0.5 in a dry environment, the friction coefficient of 0.1 is a remarkably low value.
  • the surface of the washer may be fastened by applying manganese phosphate treatment, solid lubricant, molybdenum disulfide paste, etc. to reduce friction. Since such treatment has weak adhesion to the washer surface, it is not suitable for repeated retightening, disassembly, and refastening.
  • a surface treatment that can solve these problems there is a solid lubricating layer film such as DLC (diamond-like carbon film), and among them, the DLC film is further subdivided and the surface is divided by grooves and the like, which is suitable for repeated fastening.
  • DLC diamond-like carbon film
  • segment structure DLC in which a large number of discontinuous films are arranged.
  • S-DLC segment structure DLC
  • elastic deformation occurs significantly on the softer base material when the nut and washer come into contact with each other. Therefore, even if the thin film has high brittleness and high hardness, it follows the deformation of the base material. It is known that membrane destruction is unlikely to occur.
  • the washer is coated with a film having a low friction coefficient such as DLC, the friction becomes smaller within the range where the nut seat surface and the washer come into contact, so when the nut is tightened with the same torque, the seat surface resistance and friction coefficient vary. There is an advantage that it becomes smaller, the bolt axial force is improved, and the variation of the axial force is reduced.
  • S-DLC the friction reducing effect is most exhibited, and the effect of applying S-DLC is greatly exhibited.
  • the sliding surface of the washer is formed so as to have surface roughness and flatness that do not hinder the rotation of the nut when it is screwed.
  • the arithmetic average roughness Ra is preferably 50 ⁇ m or less, more preferably 6.5 ⁇ m or less, and the flatness is preferably 0.2 mm or less, further 0.05 mm or less.
  • the arithmetic mean roughness Ra is measured according to JISB0601: 2013.
  • the washer (1) of the present invention can be used by being inserted between the object to be fastened (2) and the nut (4), for example, as shown in FIGS. 2 and 14.
  • the nut (4) used together with the washer of the present invention may be a hexagon nut, but is preferably a flange nut. This is because, in the case of a flange nut, the area of the contact side surface with the washer can be increased without increasing the screw shaft portion other than the flange portion of the nut.
  • the washer manufacturing method can be roughly divided into i) removal processing (machine cutting processing, etc.) and ii) plastic working (press processing, forging processing, etc.).
  • i) is made from materials using machine tools such as NC lathes, precision automatic machines, and general-purpose lathes, and cutting tools, and has the characteristics dedicated to the object to be used.
  • ii) is excellent in manufacturing a large number of general-purpose products with the same shape, and is continuously manufactured using a mold. As an example, a small object is punched from a plate by press working to determine its shape and dimensions, and a deburring process and surface treatment result in a finished product.
  • the cutting tool for forming the washer of the present invention It is roughly divided into 1; the case where the structure is directly processed by machining and 2; the method where a mold is created and the shape is transferred using this mold.
  • direct machining of 1 by forming an end mill-shaped blade similar to a drill for drilling into a shape that suits the purpose, "easy to cut, suitable for machine tools, strength and durability of the blade There is a track record. "
  • the transferred shape has a so-called male-female relationship.
  • Cutting tools are not limited to cutting, but also include grinding wheels.
  • FIG. 21A shows an end mill shape, in which the boundary lines B3 and B4 of the washer structure are formed into a blade shape 22 formed in the shape of an ellipse or a circle, and can correspond to many hole diameters.
  • FIG. 21 (b) shows a drill 23 in the center and blades 22 forming a stress relaxation curve similar to that in (a) added to both sides of the drill 23 in a guide hole provided in the object to be cut. Therefore, it is easy to align the center of the hole with the center of the washer structure.
  • -Fig. 21 (c) has a structure in which protrusions can be mainly carved out, such as a mold, and is used when the shape of the object to be transferred is a mold to be a mother.
  • 21 (d) is an example used when a structure is formed on the bolt hole side of the washer shown in FIG. 19 (c). When the washer is in the shape of a long pipe, it is suitable for forming the washer structure of aspect B near the inner diameter end of the pipe.
  • a desired washer structure can be made by weaving a desired shape into a mold in advance.
  • the manufacturing method does not change at all except that the mold shape is different, and various washers of the present invention can be obtained without increasing man-hours. Since the transfer mold of the mold becomes a product, it is rational that the cutting tool for cutting the mold also has a shape that forms a stress concentration relaxation curve. The forging method is the same.
  • a mold for plastic working is often used.
  • Perform, v) Surface treatment is performed to obtain a finished product.
  • i) and ii) can be performed with the same mold.
  • a casting method may be adopted when making a thick washer, a washer having a special material, a large washer, or the like, and an example of a mold at that time is shown in FIG. If the mold is provided with a curved surface in advance, the washer of the present invention can be made by the conventional casting technique. There is no increase in processing man-hours.
  • FIG. 22 shows a vertical cross-sectional view of a punch die as an example of a die.
  • the thick black line between the male type (upper part) 31 and the female type (lower part) 32 represents the workpiece 33.
  • the workpiece 23 which is a flat plate (shown by the dotted line)
  • punch dies (die) 31 and 32 undergoes press plastic working with punch dies (die) 31 and 32 based on the hole, and the shoulder to hole portion is deformed downward into an elliptical shape. ..
  • the corners of the washer holes have the shape of a washer structure.
  • the bolt thread comes out from the lower side of the figure, and the nut bearing surface is screwed into the bolt from the upper side.
  • the man-hours required to create the structure do not increase if the target processing can be performed by one press processing.
  • the mold is a dedicated mold, so there is no mistake in the hole position, direction, etc.
  • FIG. 23 shows an example of the casting mold 41.
  • the ring-shaped casting 42 is shown in black, and the shaded area indicates the casting mold 41.
  • the black arrow points to the gate 43, from which molten metal is poured to fill the space, and after cooling, a black product is produced.
  • the desired washer structure is transferred to the product. Since the casting method can be formed from all directions instead of one-way processing such as press working, for example, a block-shaped mold is provided with multiple mold shapes, and a washer structure is installed inside the mold at once. It has the feature that it can be made with different dimensions from multiple angles. Molds such as casting, die casting, MIM (metal powder injection molding), lost wax, injection molding, etc., which are molded by melting materials and putting them in a mold, can have endless application deformation examples.
  • Cutting tool material The material of the cutting tool for processing can be selected and used from alloy steel, cutlery steel, carbides such as tungsten carbide (WC), ceramics, and nitrides, which have been proven in the past.
  • alloy steel cutlery steel
  • carbides such as tungsten carbide (WC), ceramics, and nitrides, which have been proven in the past.
  • the washer (1) of the present invention can be subjected to a surface treatment having effects such as rust prevention, decoration, slidability improvement, and identification, which have been conventionally required for washers.
  • a thin film coating method that can coat a coating thin film such as DLC, TiN, TiC, CrN, BN, Al 2 O 3 is PVD (physical vapor deposition), CVD (chemical vapor deposition), arc ion plating, sputtering, FCVA (filter type cassette). Dick vacuum arc), magnetron sputtering, PBII (plasma-based ion injection method), DC single-pulse CVD and the like can be used.
  • the present invention proposes an improvement in the structure of a washer used in a properly tightened bolt / nut fastener.

Abstract

La présente invention optimise une rondelle et une structure de fixation de rondelle de sorte qu'une force soit orientée principalement vers le côté d'ouverture d'un écrou en guidant la position de la force appliquée sur l'écrou vers le côté circonférentiel extérieur d'une surface d'appui d'écrou et, par conséquent, réduit une charge sur le premier filet où le boulon et l'écrou sont fixés et s'engagent. Une rondelle selon la présente invention comporte un corps de rondelle et un trou de boulon qui traverse le corps de rondelle, la rondelle ayant, dans sa section transversale verticale, un espace de non-transmission de contrainte qui s'ouvre vers le trou de boulon et qui s'étend dans la direction radiale du trou de boulon, et l'espace de non-transmission de contrainte ayant une forme annulaire concentrique centrée sur l'axe du trou de boulon.
PCT/JP2019/049481 2019-06-25 2019-12-17 Structure de fixation de rondelle WO2020261605A1 (fr)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0225710U (fr) * 1988-08-08 1990-02-20
JPH07167129A (ja) * 1993-12-13 1995-07-04 Nippon Fastener Kogyo Kk 高力ボルト・六角ナット・平座金のセット
JP2002089535A (ja) * 2000-09-19 2002-03-27 Japan Nuclear Cycle Development Inst States Of Projects 中ぐり座金
JP2018054013A (ja) * 2016-09-29 2018-04-05 株式会社青山製作所 ワッシャ及び車両構造体

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4172680B2 (ja) * 2001-06-22 2008-10-29 株式会社住友金属小倉 高力ボルト
AU2002255291A1 (en) * 2002-05-01 2003-11-17 Fusao Yamada Locking fastener
JP2008180369A (ja) * 2006-12-28 2008-08-07 Teruo Nakagami 締結構造体及び締結用組部材

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0225710U (fr) * 1988-08-08 1990-02-20
JPH07167129A (ja) * 1993-12-13 1995-07-04 Nippon Fastener Kogyo Kk 高力ボルト・六角ナット・平座金のセット
JP2002089535A (ja) * 2000-09-19 2002-03-27 Japan Nuclear Cycle Development Inst States Of Projects 中ぐり座金
JP2018054013A (ja) * 2016-09-29 2018-04-05 株式会社青山製作所 ワッシャ及び車両構造体

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