WO2018190393A1

WO2018190393A1 - Fastening structure for stud bolt and fastened member, fastening method, and stud bolt

Info

Publication number: WO2018190393A1
Application number: PCT/JP2018/015334
Authority: WO
Inventors: 茂人森; 展由浅野; 賢板敷
Original assignee: 株式会社トープラ
Priority date: 2017-04-13
Filing date: 2018-04-12
Publication date: 2018-10-18
Also published as: JP2018179144A; JP6247417B1

Abstract

Provided are a fastening structure for a stud bolt and a fastened member, a fastening method, and a stud bolt employing a structure such that the stud bolt can be fastened securely to the fastened member and a crimped portion does not protrude from the plate surface of the fastened member. Multiple protrusions 51 extending in the axial direction are provided in the circumferential direction on a crimping shaft section 5; the threaded shaft section 4 of the stud bolt 1 is inserted into a pilot hole 101 in a metal thin plate 100, and the crimping shaft section 5 is press-fitted against the inner circumference of the pilot hole 101 of the metal thin plate 100, thereby causing the protrusions 51 to bite into the inner circumference of the pilot hole 100; by crimping the end portion protruding on the threaded-shaft side of the pilot hole 100, an overhanging part 54 overhanging in the radial direction is formed; the metal thin plate 100 is clamped in the axial direction between the overhanging part 54 and a shoulder section 23 of a stud section 2; and in addition, an annular recess 102 is provided by locally indenting the peripheral edge of the pilot hole 101 of the metal thin plate 100 with the overhanging part 54.

Description

Fixing structure, fixing method and stud bolt between stud bolt and fixed member

The present invention relates to a stud bolt that is fixed such that a stud portion on which a part is mounted protrudes on one surface of a fixed member and a screw shaft portion protrudes on the other surface, and in particular, a stud bolt and a fixed member. The present invention relates to a fixing structure, a method for fixing a stud bolt and a fixed member, and a stud bolt used for the fixing method.

As a conventional fixing structure of this type of stud bolt, for example, a structure described in Patent Document 1 is known.
That is, as shown in FIGS. 11A and 11B, the stud bolt 401 has a head portion 405 having the largest outer diameter and a shaft of a component 402 such as a pulley fixed from the head portion 405 to the tip side. A first shank 406, a shoulder 409 having an annular groove 410 of the first shank 406, a second shank 407 having a diameter smaller than that of the first shank 406, and a screw shaft at the tip of the second shank 407. It has a structure having 408.
By inserting the second shank 407 into the metal plate 403, which is a fixed member having a hole having a diameter equal to or larger than that of the second shank 407, and cold-working the second shank 407, By forming a crushing portion 407a compressed in the direction and expanded in the radial direction and fitting into the edge portion 403a of the hole of the metal plate 403, the component 402 inserted into the first shank 406 is inserted into the metal plate 403. It comes to be attached to. An edge portion 403 a of the hole of the metal plate 403 is bent into the annular groove 410.

US Pat. No. 6,607,339

However, considering that the other fastening plate 411 is screwed to the metal plate 403 of the structure using the screw shaft 408 of the stud bolt 401, the height of the expanded portion 407a of the expanded second shank is If the height is not equal to or less than the fastening surface of the metal plate 403, the fastening plate 411 is not in close contact, and if the gap g is generated, normal fastening cannot be performed, and loosening may occur. It is very difficult to suppress the height of the crushing portion 407a of the second shank, and it is necessary to chamfer the pilot hole of the metal plate 412.
Further, in order to keep the expanded crushing portion 407a within the height of the fastening surface of the metal plate 403, it is conceivable to increase the pressing force of the second shank 407. A large bending stress acts on the metal plate 403, and the metal plate 403 is greatly deformed to warp around the first shank 406 as shown by a two-dot chain line in FIG. There arises a problem that the part 402 does not move smoothly.
Further, Patent Document 1 discloses an example in which an annular groove does not exist in the shoulder portion 409 of the first shank 406, but it protrudes without a portion in which the material of the collapsed portion 407a of the expanded second shank 407 fits. The height cannot be equal to or lower than the fastening surface of the metal plate 403, and the gap is further increased.
The present invention has been made in order to solve the above-described problems of the prior art, and an object of the present invention is to firmly fix the stud bolt to the member to be fixed, and the screw shaft portion projects from the crimped portion. An object of the present invention is to provide a fixing structure, a fixing method, and a stud bolt between a stud bolt and a fixed member that do not protrude from the plate surface of the fixed member on the side.

In order to achieve the above object, a fixing structure of a stud bolt and a member to be fixed according to the present invention includes a stud portion, a caulking shaft portion extending in an axial direction from the stud portion, and an opposite side of the stud portion of the caulking shaft portion. A screw shaft portion extending in an axial direction from the end portion on the side, the caulking shaft portion is fixed to a fixing hole of the fixed member, and a stud portion protrudes from one surface of the fixed member, and the other surface In the fixing structure of the stud bolt and the fixed member having a structure in which the screw shaft portion protrudes,
On the outer periphery of the caulking shaft portion, an axially extending ridge that is fitted into a plurality of axial grooves formed on the inner periphery of the fixing hole of the fixed member is provided,
At the end on the screw shaft portion side of the ridge, a protruding portion that protrudes radially outward and engages with a peripheral edge portion of the fixing hole of the fixed member is provided,
On the peripheral edge of the fixing hole of the fixed member, an annular recess that is locally recessed with the overhang is formed,
An inner diameter of the annular recess is larger than an inner diameter that is a diameter on a base side of the ridge, and is smaller than an outer diameter.
According to the present invention, the protruding portion of the caulking shaft portion is closely fitted in the axial groove of the fixing hole of the fixed member, and the protruding portion provided on the end portion of the protruding item is fixed. Because it engages with the peripheral edge of the hole, it is strong against loads in various directions such as axial pulling load and bending force in the direction perpendicular to the axis, not only in the torsional direction, even if the fixed member is thin. Can be joined.
Furthermore, by forming an annular recess that is recessed locally along with the overhang at the periphery of the fixing hole of the member to be fixed, the overhang does not protrude from the plate surface of the member to be fixed.

The stud portion includes a shank portion that rotatably supports a part, and the shank portion has a diameter larger than the diameter of the end portion on the shank portion side of the caulking shaft portion, and the caulking shaft portion side of the shank portion. Is connected to the caulking shaft portion via a shoulder portion that forms a step, the shoulder portion contacts the fixed member, and the fixed member is interposed between the shoulder portion and the overhanging portion. It can be set as the structure inserted | pinched in an axial direction.
With such a configuration, the component can be stably supported particularly when a bending load in the direction perpendicular to the axis acts on the shank portion from the component.
The stud portion includes a shank portion that rotatably supports and slides a component through a collar.
The diameter of the shank portion is the same as the diameter of the end portion on the shank portion side of the caulking shaft portion, the end surface on the caulking shaft portion side of the collar is in contact with the fixed member, and the fixed member is attached to the collar It can also be set as the structure pinched in the axial direction between the end surface by the side of a crimping shaft part and the said overhang | projection part.
Even with such a configuration, the component can be stably supported when a bending load in the direction perpendicular to the axis acts on the shank portion from the component.
Further, another fastening plate may be stacked on the fixed member, and the fastening plate may be fixed by a female screw component screwed into the screw shaft portion.
When the fastening plate is fixed in this way, the overhanging portion is accommodated in the annular recess, so that the member to be fixed and the fastening plate can be closely bonded without any gap.

The stud bolt and the fixing member of the present invention include a stud portion, a caulking shaft portion extending in the axial direction from the stud portion, and an axial direction from an end portion of the caulking shaft portion opposite to the stud portion. In a fixing method of a stud bolt and a fixed member for fixing a stud bolt having a threaded shaft portion having a male screw extending to a fixed member having a fixing pilot hole,
The caulking shaft portion is provided with a plurality of protrusions extending in the axial direction in the circumferential direction,
By inserting the threaded shaft portion of the stud bolt into the pilot hole of the member to be fixed and press-fitting the caulking shaft portion into the inner periphery of the pilot hole of the member to be fixed, the protrusions are bitten into the inner periphery of the pilot hole. ,
By crimping the end of the ridge that protrudes toward the screw shaft side of the pilot hole, a bulge that expands in the radial direction is formed, and the bulge is engaged with the peripheral edge of the pilot hole. ,
Furthermore, the peripheral part of the pilot hole of the fixed member is locally depressed together with the projecting part to form an annular recess,
An inner diameter of the annular recess is larger than an inner diameter that is a diameter on a base side of the ridge, and is smaller than an outer diameter.
According to the fixing method of the stud bolt and the fixed member of the present invention, the caulking shaft portion is press-fitted into the inner periphery of the lower hole of the fixed member, and the end of the protruding shaft on the screw shaft portion side is simply caulked. A fitting structure having an axial groove that fits the ridge around the periphery can be formed, and an overhanging portion that engages with the peripheral edge of the pilot hole can be formed at the end of the ridge. Furthermore, by projecting from the plate surface of the fixed member including the overhanging portion, it is possible to prevent the protruding portion from protruding from the plate surface of the fixed member.
Further, since the caulking is configured to partially caulk the ends of the ridges, an excessive crimping force is unnecessary.
The stud portion includes a shank portion that rotatably supports a part, and the shank portion has a diameter larger than a diameter of an end portion on the shank portion side of a caulking shaft portion, and the caulking shaft portion of the shank portion. The end on the side is connected to the caulking shaft portion via a shoulder portion that forms a step, the shoulder portion contacts the fixed member, and the fixed member is placed between the shoulder portion and the overhanging portion. It can also be configured so as to be sandwiched in the axial direction.
The stud portion includes a shank portion that rotatably supports and slides a component through a collar, and the diameter of the shank portion is the same as the diameter of the end portion on the shank portion side of the caulking shaft portion, An end surface of the collar on the side of the caulking shaft may be brought into contact with the member to be fixed, and the fixing member may be sandwiched between the end surface on the side of the caulking shaft of the collar and the protruding portion in the axial direction. it can.
The caulking of the ridge is performed by a caulking die having a hole through which the screw shaft portion is inserted, and a ring convex portion for forming the annular concave portion is provided on the peripheral edge of the caulking die. can do.
By using a caulking die having an annular convex portion in this way, it is possible to perform press fitting of the caulking shaft portion, caulking of the ridges, and formation of the annular concave portion with a single die.

The stud bolt of the present invention includes a stud portion, a caulking shaft portion that extends in an axial direction from the stud portion, and is fixed to a prepared hole of a fixed member, and the caulking shaft portion on the side opposite to the stud portion. A stud bolt having a screw shaft portion extending in an axial direction from an end portion,
A plurality of ridges extending in the axial direction are provided on the outer periphery of the caulking shaft portion in the circumferential direction,
The outer diameter of the ridge is larger than the hole diameter of the pilot hole of the fixed member, and the inner diameter of the base side of the ridge is smaller than the hole diameter of the pilot hole,
The length of the ridge is longer than the thickness of the member to be fixed, and the end on the screw shaft side of the ridge protruding from the member to be fixed is caulked when being fixed to the member to be fixed. The caulking part
An inner diameter of the annular recess is larger than an inner diameter that is a diameter on a base side of the ridge, and is smaller than an outer diameter.
The caulking shaft portion may be provided with a tapered portion at the end on the screw shaft portion side that is reduced in diameter so that the diameter gradually decreases toward the tip of the screw shaft portion.
In this way, during the caulking operation, the center hole of the fixed member and the center of the caulking shaft portion of the stud bolt are automatically aligned, and the positions of the protrusions and the edge portions of the pilot hole can be accurately positioned. it can.
The portion on the stud portion side of the valley portion between the ridges can be configured as an inclined portion that gradually inclines radially outward toward the stud portion side.
If it does in this way, when it press-fits in the prepared member's pilot hole, the metal material of the to-be-fixed member which approachs a trough part will be compressed in a wedge shape, will contact a trough part closely, and joint strength will increase.
Further, the plurality of ridges provided on the caulking shaft portion can be knurled portions. If it does in this way, a protruding item | line can be formed easily.

According to the present invention, the stud bolt can be firmly fixed to the fixed member, and there is no gap between the plate surface of the thin metal plate on the side from which the screw shaft portion protrudes and the fastening surface of the mating member.

1A and 1B show a fixing structure between a stud bolt and a thin metal plate according to an embodiment of the present invention. FIG. 1A is a front view partially showing a fixing portion with the thin metal plate, and FIG. The partial enlarged view schematically showing the vicinity of the annular recess of the metal thin plate of (A) as viewed from the shaft tip direction, (C) is a partial enlarged sectional view taken along the line CC of (B), and (D) is D of (B). FIG. 2 shows the stud bolt of FIG. 1, (A) is a front view, (B) is a cross-sectional view taken along line BB of (A), and (C) is a partially enlarged view near the knurled portion of (A). FIG. FIG. 3 is an explanatory view for explaining the dimensional relationship among the stud bolt, the metal thin plate, and the caulking die. 4 (A) to 4 (C) are diagrams showing the steps of the method for fixing the stud bolt and the metal thin plate of the present invention. FIGS. 5A to 5H are explanatory views for explaining the steps of the fixing method of the present invention in more detail. 6A and 6B show a modification of the stud bolt of FIG. 2, in which FIG. 6A is a front view and FIG. 6B is a partially broken partial enlarged view of FIG. FIG. 7 is a partially cutaway front view of a structure in which another fastening plate is fixed to the metal thin plate of FIG. FIGS. 8A to 8H are views showing other forms of the stud bolt of the present invention. FIG. 9 shows a fixing structure between the stud bolt and the thin metal plate in FIG. 8 (D), (A) is a front view partially showing a fixing portion with the thin metal plate, and (B) is the direction of the screw shaft tip. (A) A partially enlarged view schematically showing the vicinity of an annular recess of a thin metal plate of (A), (C) is a partially enlarged sectional view taken along line CC of (B), and (D) is a DD line of (B). It is a partial expanded sectional view. FIGS. 10A to 10C are views showing steps of the method for fixing the stud bolt and the metal thin plate in FIG. 8D, and FIG. 10D is a partially enlarged view of FIG. 11A and 11B show a conventional structure for fixing a stud bolt and a metal plate. FIG. 11A is a perspective view of the stud bolt, and FIG. 11B is a cross-sectional view of a structure to which the metal plate is fixed.

Hereinafter, the present invention will be described in detail based on illustrated embodiments.
[Embodiment]
FIG. 1 shows a fixing structure of a stud bolt according to an embodiment of the present invention and a metal thin plate as an example of a member to be fixed, and FIG. 2 shows the stud bolt.
First, a stud bolt will be described with reference to FIG.
The stud bolt 1 includes a stud portion 2, a caulking shaft portion 3 extending in the axial direction from the stud portion 2, and a complete thread 41 extending in the axial direction from an end portion of the caulking shaft portion 3 opposite to the stud portion 2. And a threaded shaft 4.
The stud portion 2 includes a cylindrical shank portion 21 that supports the component 300 so as to be rotatable and slidable, and a head portion having a larger diameter than the shank portion 21 provided on the end portion of the shank portion 21 opposite to the caulking shaft portion 3. 22. A center hole 22 a for determining the center is provided on the top surface of the head portion 22. The shank portion 21 serves as an axis of a component to be inserted, and in order to realize smooth movement, the shank portion 21 may have a shape in which a groove or a flat portion that can hold grease or the like is provided.
The shank portion 21 has a diameter larger than the diameter of the end portion on the shank portion side of the caulking shaft portion 3, and the end portion on the caulking shaft portion 3 side of the shank portion 21 is caulked shaft portion via a shoulder portion 23 that forms a step. 3 is connected. The shoulder portion 23 is configured by an annular flat surface that is orthogonal to the central axis of the stud portion 2.

The caulking shaft portion 3 includes a knurled portion 5, a rounded portion 55 a that gradually increases in diameter from the upper end of the knurled portion 5 toward the shoulder portion 23 of the shank portion 21, and a knurled portion. 5 and a tapered portion 53 that gradually decreases in diameter from the lower end to the lower side. The position of the connection end of the rounded portion 55a with the shoulder portion 23 is the end portion position of the caulking shaft portion 3 on the shank portion 23 side.
As illustrated in detail in FIGS. 2B and 2C, the knurled portion 5 is a portion that is fixed to the pilot hole 101 of the thin metal plate 100 as an example of a member to be fixed, and is a protruding line 51 that extends in the axial direction. Are formed in the circumferential direction. In this example, the cross-sectional shape of the ridge 51 in the direction perpendicular to the axis (perpendicular to the center axis of the stud bolt) is a triangular mountain shape, and the ridges 51 are repeatedly formed at a predetermined pitch in the circumferential direction.
The outer diameter D1 at the distal end in the radial direction of the ridge 51 is larger than the hole diameter D0 of the prepared hole 101 of the metal thin plate 100 to be fixed (D1> D0), and is a knurling process that is the diameter on the base side of the ridge 51. The inner diameter D2 of the portion 5 is smaller than the hole diameter D0 of the prepared hole 101 (D0> D2) (FIG. 2B). The inner diameter D2 of the knurled portion 5 is set larger than the outer diameter (nominal diameter) d of the complete thread 41 of the screw shaft portion 4.
Considering the pilot hole diameter of the fastening plate that is finally fastened by the complete thread 41 of the screw shaft portion 4, it is desirable that the outer diameter D1 be suppressed to a screw nominal diameter d + 1 mm.
The number of ridges 51 of the ridges 51 is preferably set to 16 to 40 ridges in consideration of the joining state of the metal thin plate 100 when the pilot hole 101 is inserted into the metal thin plate 100.
The end of the knurled portion 5 on the stud portion side is an annular portion 55 to which the ends of the ridges 51 are connected. The valley 52 between the ridges 51 and the ridges 51 has a knurled portion 5. A triangular inclined portion 52a having a gradually increasing diameter from the axially intermediate portion toward the axial stud portion side is provided. The inclined portion 52a is expanded to the height of the ridge 51 and connected to the annular portion 55, and the annular portion 55 is connected to the shoulder portion 23 via the rounded portion 55a.

Further, the taper portion 53 is configured to reduce the diameter so that the diameter gradually decreases from the end on the screw shaft portion 4 side of the knurled portion 5 toward the tip of the screw shaft portion 4, and the knurled portion 5 is a thin metal plate. When inserted into the pilot hole 101 of 100, the centering function is fulfilled. The end surface of the ridge 51 on the screw shaft portion 4 side also has a tapered shape that continues to the taper portion 53, the valley portion 52 is opened to the screw shaft portion side, and the boundary between the taper portion 53 and the knurled portion 5. The part has a zigzag shape with ridges 51 and valleys 52.
When the ridge 51 is caulked and fixed to the metal thin plate 100, the end on the screw shaft side is caulked by a predetermined length in the axial direction. In order to ensure the characteristics after caulking and to perform strong joining by the caulking method of the present invention, the length L1 from the shoulder 23 of the stud 2 to the end of the knurled portion 5 is a metal thin plate 100 as a base material. It is necessary to make it longer than the plate thickness t (L1> t).

The threaded shaft portion 4 gradually increases in height from the parallel thread portion 4A in which the complete thread 41 of the male thread is formed, the neck portion 4B having no thread, and the neck portion 4B toward the parallel thread portion 4A. A transition screw portion 4C in which an introduction screw thread 42 having an outer diameter that satisfies the JIS standard value is formed, and a round portion 4D that connects the neck portion 4B and the taper portion 53 are provided.
The starting position of the introduction screw thread 42 is preferably set so that the distance L2 from the shoulder portion 23 of the stud portion 2 is within two pitches in order to ensure a perfect thread engagement ratio with the female thread component.
The diameter of the neck portion 4B without the screw and the valley diameter d2 of the transition screw portion 4C are smaller than the minimum inner diameter value of the female screw JIS standard value.

Next, a fixing structure between the stud bolt and the fixed member will be described with reference to FIG.
FIG. 1A is a front view showing a partially broken metal sheet, FIG. 1B is a partially enlarged view seen from the direction B of FIG. 1A, and FIG. C line sectional view, (D) is a DD line sectional view cut along the valley of (B). In the following description, the description will focus on the joint between the stud bolt and the thin metal plate.
The stud bolt 1 is press-fitted and fixed to the fixing hole 110 of the metal thin plate 100, which is a thin plate base material, with the caulking shaft portion 3 being rotatably inserted into the shank portion 21 of the stud portion 2. The stud portion 2 protrudes from one surface of the thin plate 100 and the screw shaft portion 4 protrudes from the other surface. The thickness of the component 300 in the axial direction is shorter than the length of the shank portion 21, the shoulder portion 23 of the shank portion 21 contacts one plate surface of the thin metal plate 100, and the component 300 that is rotatably mounted on the shank portion 21 is The axial movement is regulated by the head portion 22 of the stud portion 2 and the metal thin plate 100.
The inner peripheral shape of the fixing hole 110 is a shape that follows the shape of the knurled portion 5, and is formed by press-fitting the knurled portion 5 of the stud bolt 1 into the prepared hole 101 of the thin metal plate 100. That is, the inner peripheral shape of the fixing hole 110 is formed with a plurality of axial grooves 112 in the circumferential direction in which the ridges 51 of the knurled portion 5 are closely fitted, and between the axial grooves 112 and the axial grooves 112, An inner peripheral convex portion 111 that is closely fitted to the valley portion 52 of the knurled portion 5 is formed. Furthermore, an inner peripheral inclined portion 111 a is formed at the end of the inner peripheral convex portion 111 on the stud portion side so that the inclined portion 52 a of the knurled portion 5 is in close contact with the inner peripheral convex portion 111.

In addition, a protruding portion 54 that protrudes radially outward and engages with the peripheral portion of the fixing hole 110 on the plate surface of the metal thin plate 100 on the screw shaft portion side is provided at the end of the protrusion 51 on the screw shaft portion side. The thin metal plate 100 is fixed between the projecting portion 54 and the shoulder portion 23 of the stud portion 2 so as to be sandwiched in the axial direction.
Further, the rounded portion 55a located at the stud portion side end of the caulking shaft portion 3 bites into the opening edge on the stud portion side of the fixing hole 110 of the thin metal plate 100, and the shoulder portion 23 is on the stud portion side of the thin metal plate 100. Touch the plate surface.
An annular recess 102 that can be recessed locally together with the overhanging portion 54 is formed at the peripheral edge of the fixing hole 110 of the thin metal plate 100. The inner diameter D3 of the annular recess 102 is larger than the inner diameter D2 of the knurled portion 5 (FIG. 1 (D)) and smaller than the outer diameter D1 (FIG. 1 (C)). In addition, the outer diameter D4 of the annular recess 102 is larger than the outer diameter D1 of the knurled portion 5 (FIG. 1C).
The overhang portion 54 is a portion formed by caulking the end of the ridge 51 on the screw shaft portion side, and the top portion of the ridge 51 is cut from the overhang portion 54 to the tip of the screw shaft portion side during caulking. In other words, the arcuate surface constitutes a part of the inner peripheral wall of the annular recess 102.

Next, a method for fixing the stud bolt and the metal thin plate will be described.
First, the caulking die 200 used for the caulking structure of the stud bolt 1 will be described with reference to FIG.
The caulking die 200 is a cylindrical body having a hole 201 having a circular cross section into which the screw shaft portion 4 of the stud bolt 1 can be inserted, and the opening of the hole 201 that opens to the end surface on the side where the screw shaft portion 4 is inserted. An annular projection 202 protrudes from the edge.
The inner diameter of the annular convex portion 202 is the same as the inner diameter Da of the hole 201, is smaller than the outer diameter D1 of the knurled portion 5, and is larger than the inner diameter D2. This dimensional relationship is the same as the hole diameter D0 of the pilot hole 101 of the metal thin plate 100, but the inner diameter Da of the annular convex portion 202 and the hole diameter D0 of the pilot hole 101 may be the same or different. . The caulking die 200 has an inner diameter Da that is larger than the screw outer diameter d of the screw shaft portion 4, and the mouth is generally provided with a radius R that is approximately the same as the top of the screw thread of the bolt.
The outer diameter Db of the annular convex portion 202 is smaller than the outer diameter Ds of the shank portion 21 of the stud portion 2 and larger than the outer diameter D1 of the knurled portion 5. Further, the height T1 of the annular convex portion 202 protruding from the mold surface 200a is about 10% to 50% of the thickness of the base metal thin plate 100.
Next, with reference to FIG. 4, the fixing method of the stud bolt 1 and the metal thin plate 100 using the said crimping metal mold | die 200 is demonstrated.
First, the screw shaft portion 4 is inserted into the pilot hole 101 of the thin metal plate 100 as a base material in a state where the component 300 is assembled into the stud portion 2 of the stud bolt 1 in the caulking die 200 (see FIG. 4A). ), The screw shaft portion 4 of the stud bolt 1 is inserted into the hole 201 of the caulking die 200 (see FIG. 4B).
From this state, between the head portion 22 of the stud bolt 1 and the caulking die 200 is compressed in the axial direction by a press (not shown) (cold working), and the knurled portion 5 is formed in the inner periphery of the pilot hole 101 of the metal thin plate 100. While being press-fitted, the axial end of the knurled portion 5 projecting toward the screw shaft 4 side of the pilot hole 101 is fixed so as not to be relatively movable in the twisting direction and the axial direction (FIG. 4C )reference).
As a result of this processing, the knurled portion 5 bites into the inner wall of the prepared hole 101 of the thin metal plate 100 as a base material, and the knurled portion 5 protruding in the plate thickness direction is installed to expand in the radial direction. By being sandwiched between the inflated projecting portion 54 of the knurled portion 5 and the shoulder portion 23 of the stud portion 2, even if the thickness of the metal thin plate 100 is thin, it can be firmly joined.

Next, the press-fitting and caulking process will be described in detail with reference to FIG. FIG. 5 is an enlarged view of the vicinity of each part of the knurl during caulking.
5A and 5B correspond to the position of FIG. 4B, and the edge portion 101a on the stud portion side of the pilot hole 101 of the thin metal plate 100 is located on the end surface of the ridge 51 on the screw shaft portion side. The contact state is shown. Even if the lower hole 101 of the thin metal plate 100 and the center axis of the stud bolt 1 are misaligned, the taper portion 53 automatically aligns and the edge of the lower hole 101 is positioned at an intermediate position between the inner diameter and outer diameter of the ridge 51. . In the drawing, the inner diameter of the annular convex portion 202 of the caulking die 200 is the same as the hole diameter D0 of the pilot hole 101 of the metal thin plate 100, but it is not necessary to be the same.
If it compresses with a press in this state, as shown to FIG.5 (C), (D), the knurl process part 5 will be press-fitted in the inner wall of the pilot hole 101 of the metal thin plate 100 used as a base material. By this press-fitting, the inner periphery of the pilot hole 101 of the thin metal plate 100 is plastically deformed following the shape of the knurled portion 5, the axial groove 112 corresponding to the ridge 51 of the knurled portion 5, and the valley of the knurled portion 5. An inner peripheral convex portion 111 corresponding to the portion 52 is formed.
In this press-fitting process, the ridges 51 of the knurled portion 5 are closely fitted in the axial groove 112, and the inner peripheral convex portion 111 is closely fitted in the valley 52, and the torque resistance in the torsional direction is improved. Secured.

Furthermore, as shown in FIG. 5 (E), the inner peripheral convex portion 111 bites into the inclined portion 52a of the knurled portion 5 in a wedge shape to form the inner peripheral inclined portion 111a, and the close contact degree of the inner peripheral convex portion 111 is increased and caulking is performed. The opening edge of the annular convex portion 202 of the mold 200 abuts on the end surface of the screw shaft portion 4 of the knurled portion 5.
Thereafter, as shown in FIGS. 5 (F) and 5 (G), a portion having a diameter larger than the hole diameter Da of the caulking die in the ridge 51 of the knurled portion 5 is set on the stud portion 2 side. The caulking starts. By this caulking, a protruding portion 54 that protrudes in the radial direction is formed at the end of the ridge 51 of the knurled portion 5 on the screw shaft portion side. As the caulking progresses, the protruding portion 54 increases in the radial direction, and enters the wedge shape between the tip surface of the annular convex portion 202 and the contact surface of the metal thin plate 100.
And as shown to FIG.5 (G), (H), after the fastening surface by the side of the stud part of the metal thin plate 100 contact | abuts to the shoulder part 23, it is further pressurized by the annular convex part 202, The peripheral edge of the fixing hole 110 is pressed and caulked until the mold surface 200a comes into contact with the metal thin plate 100, and the caulking is finished. An annular recess 102 in which the annular protrusion 202 bites is formed at the periphery of the fixing hole 110 so that the overhanging portion 54 does not protrude from the plate surface on the screw shaft portion 4 side of the original thin metal plate 100. It is held down.
As described above, press fitting and caulking can be performed while the end surface of the annular convex portion 202 of the caulking die 200 and the flat surface of the die surface 200a and the shoulder portion 23 of the stud portion are in contact with each other. There will be no deformation.
The thickness of the thin metal plate 100 used for this processing is 1 mm or less, and the thickness is 1 pitch or less of the applied screw.
In addition, when the plate | board thickness t of the metal thin plate 100 is restrict | limited and it is difficult to ensure the length of the effective knurl processed part 5, as shown in FIG. 6, the shoulder part 23 of the stud part 2 and the knurl processed part 5 are made. By providing the undercut portion 24 that dents the connecting R portion on the shoulder portion 23 side of the stud portion 2, the long knurled portion 5 can be engaged with the prepared hole 101 of the metal thin plate 100.

Strength Verification Next, the strength test result of the structure having the structure for fixing the stud bolt and the metal thin plate of the present invention will be described.
In FIG. 7, the structural example of the structure used for the test is shown. In this structure, a fastening plate 310 is overlapped on the metal thin plate 100 of the assembly of the stud bolt 1 and the metal thin plate 100 on which the component 300 is mounted, and is fastened and fixed with a nut 320.
As a result of applying loads in various directions to this structure, the torsional strength at the time of fastening and the required joint strength for use were satisfied as follows.
・ Axial pull-out load With only press-fitting of the knurled part 5, the average is 0.33 kN (min 0.25 kN to max 0.41 kN).
In the present invention, the average was 0.70 kN (min 0.68 kN to max 0.72 kN).
・ Bending load in the direction perpendicular to the axis With only the press-fitting of the knurled part 5, the average is 0.56 kN (min 0.50 kN to max 0.61 kN),
In the present invention, the average was 0.77 kN (min 0.72 kN to max 0.84 kN).
・ Torsion separation strength Even if the tightening torque was applied until the screw shaft 4 was broken, there was no abnormality in the caulking fixing portion.
As a result of applying torque to the stud bolt after crimping having a threaded part of M6, strength category 9.8, 26N. The screw shaft portion 4 was broken at m.
* The test was conducted with a thickness of 1 mm of the thin metal plate 100 as a caulking base material and a thickness of 0.6 mm of the clamping plate 310.

Other Forms In the above embodiment, the stud portion 2 includes the columnar shank portion 21 that slides and guides the component 300 and the head portion 22 having a larger diameter than the shank portion 21, and the shoulder portion 23 of the stud portion 2. Corresponds to the shoulder portion of the shank portion 21, but the configuration of the stud portion 2 can be various as shown in FIGS. 8 (A) to (H). In the following description, the same components as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted.
Other form 1
In FIG. 8A, the shank portion 21 into which the component 300 is rotatably inserted has a two-stage shape of a large-diameter cylindrical first shank 21A and a small-diameter cylindrical second shank 21B. The shoulder 23 of the second shank 21 </ b> B abuts on the thin metal plate 100.
On the other hand, the component 300 such as a pulley contacts the outer periphery of the first shank 21A so as to be freely slidable, and the second shank 21B is not a shaft that supports the component 300 but a gap is formed between the inner periphery of the component 300. ing.
Other form 2
8B and 8C show another embodiment 2, FIG. 8B is a front view of a stud bolt showing a part and a thin metal plate in cross section, and FIG. 8C is a cross-sectional view of the shank portion in the direction perpendicular to the axis. .
As shown in FIGS. 8B and 8C, in this embodiment, the shank portion 21 of FIG. 1 is provided with a two-sided width portion 21C, and the shape of the shank portion 21 is a non-cylindrical shaft shape. It is. By providing the two-surface width 21C, the weight can be reduced.
Other form 3
FIG. 8D shows another embodiment 3.
In the third embodiment, the diameter of the shank portion 21D into which a component 300 such as a pulley is inserted is reduced, and the knurled portion 5 is caulked while the collar 26 is inserted. That is, the diameter of the position where the collar 26 of the shank portion 21D exists is reduced, and the shoulder portion 23 connected to the knurled portion 5 is eliminated from the shank portion 21 of FIG. In this case, the thin metal plate 100 is sandwiched in the axial direction between the overhanging portion where the convex portion 51 of the knurled portion 5 is crimped and the collar 26.
Other form 4
FIGS. 8E and 8F show another embodiment 4, FIG. 8E is a front view of a stud bolt showing a part and a thin metal plate in section, and FIG. 8F is a plan view of the stud bolt.
As shown in FIGS. 8E and 8F, the planar shape of the head portion 22E is not a circle but a square shape with round corners. In addition, you may combine the shape of this head part 22E with other above-mentioned

form

1,2,3.
Other form 5
In FIG. 8G, a flange portion 29 having a diameter larger than that of the shank portion 21 is provided below the shank portion 21 where the component 300 such as a pulley is located. The metal sheet 100 is caulked at the knurled portion 5 below the flange 29.
Further, instead of the head portion of FIG. 1, a cylindrical projection 27 is provided at the upper end of the shank portion 21, has an inner diameter larger in diameter than the projection 27, and has an outer diameter larger than that of the shank portion 21. A washer 302 having a diameter is caulked while the projection 27 is deformed, and the component 300 is sandwiched between the shank part 21.
The washer 302 is fixed simultaneously with caulking of the knurled portion 5 to the metal thin plate 100.
Other form 6
8H, similarly to FIG. 8G, a flange portion 29 having a diameter larger than that of the shank portion 21 is provided below the shank portion 21 into which the component 300 is fitted. The knurled portion 5 is caulked to the thin metal plate 100.
In this embodiment 6, a recess 28 is provided at the upper end of the shank portion 21, and the peripheral portion 28 a of the recess 28 is plastically deformed so as to be larger than the outer diameter of the shank portion 21, so that the component 300 is sandwiched between the shank portion 21. It has become. The fixing of the component 300 is also performed simultaneously with the caulking of the knurled portion 5 to the metal thin plate 100.

Hereinafter, the other embodiment 3 will be described in more detail with reference to FIGS. 9 and 10.
FIG. 9 shows a fixing structure between the stud bolt and the member to be fixed (metal thin plate).
In the third embodiment, the shank portion 21D supports the component 300 via the collar 26 so as to be slidable and slidable. The diameter of the shank portion 21D is the end of the caulking shaft portion 3 on the shank portion 21D side. The circular shape is the same as the maximum diameter of the round portion 55a. The collar 26 has a cylindrical shape, the axial length is the same as the axial length of the shank portion 21D, and one end face 26b of the collar 26 contacts the head portion 22 while being fixed to the thin metal plate 100, and the other The end surface 26 a of the metal plate 100 is in contact with the plate surface of the metal thin plate 100 on the stud portion 2 side. The thin metal plate 100 is sandwiched between the end surface 26a of the collar 26 on the caulking shaft portion side and the protruding portion 54 in the axial direction.
9 is compared with FIG. 1, the portion corresponding to the shoulder portion 23 of the stud portion 2 of FIG. 1 is replaced with a collar 26 fitted to the outer periphery of the shank portion 21 </ b> C. The detailed description is omitted. By using the collar 26, it is possible to deal with parts of various sizes.
Next, a method for fixing the stud bolt 1 and the metal thin plate 100 using a caulking die will be described with reference to FIG.
First, in a state in which the collar 26 and the component 300 are assembled in the shank portion 21D of the stud bolt 1, the screw shaft portion 4 is inserted into the pilot hole 101 of the thin metal plate 100 as a base material (see FIG. 10A). The screw shaft portion 4 is inserted into the hole 201 of the caulking die 200 (see FIG. 10B).
In the illustrated example, the collar 26 moves downward by its own weight with respect to the outer periphery of the shank portion 21D and is in contact with the thin metal plate 100. However, the collar 26 is frictionally engaged with the outer periphery of the shank portion 21D and has a shaft depending on its own weight. It is good also as a fitting dimension of the grade which does not move to a direction.
From this state, between the head portion 22 of the stud bolt 1 and the caulking die 200 is compressed in the axial direction by a press (not shown) (cold working), and the knurled portion 5 is formed in the inner periphery of the pilot hole 101 of the metal thin plate 100. While being press-fitted, the axial end of the knurled portion 5 projecting toward the screw shaft 4 side of the pilot hole 101 is fixed so as not to be relatively movable in the torsional direction and the axial direction (FIG. 10 (C )reference). At the end of the caulking, the upper end surface 26 b of the collar 26 contacts the lower surface of the head portion 22 of the stud portion 2, and the lower end surface 26 a contacts the upper surface of the thin metal plate 100.
That is, as shown in an enlarged view in FIG. 10D, the knurled portion 5 bites into the inner wall of the prepared hole 101 of the thin metal plate 100 as the base material, and the knurled portion 5 protruding in the thickness direction is set up. Rarely, an end projecting toward the screw shaft portion 4 of the lower hole 11 of the ridge 51 is caulked to project in the radial direction, and an overhanging portion 54 that engages with the peripheral edge of the lower hole 101 is formed. The thin metal plate 100 is sandwiched between the protruding portion 54 and the lower end surface 26 a of the collar 26, and the peripheral portion of the pilot hole 101 of the thin metal plate 100 is locally recessed together with the protruding portion 54 to form an annular recess. 102 is formed.
Note that the details of the caulking process of the knurled portion 5 are merely replacing the shoulder portion 23 of the above-described embodiment shown in FIG.

As described above, according to the present invention, the mounting strength of the component 300 to the metal thin plate 100 of the stud bolt 1 can be improved, and further, the fastening strength when the structure is fastened to the fastening plate can be improved. Can be secured, and weight reduction around the parts can be achieved.
Further, when fastening to various fastening plates using the screw shaft portion 4 at the tip, the plate thickness can be fastened even with a thickness of one pitch or less of the applied screw.

DESCRIPTION OF SYMBOLS 1 Stud bolt 2 Stud part 21 Shank part, 22 Head part, 22a Center hole 23 Shoulder part, 24 Undercut part 21A 1st shank, 21B 2nd shank 21C Two-sided width 21D Shank part 26 Collar, 26a lower end face, 26b top End face 27 Protruding part 28 Dimple, 28a peripheral part 29 Claw part 3 Caulking shaft part 4 Screw shaft part 4A Parallel thread part, 4B Neck part, 4C Transition thread part, 4D Earl part 41 Complete thread, 42 Introduction thread 5 Knurled part 51 ridge, 51a end, 52 valley, 52a inclined part 53 taper part, 54 overhang part, 55 annular part 100 metal thin plate 101 pilot hole, 102 annular concave part,
DESCRIPTION OF SYMBOLS 110 Fixing hole, 111 Inner peripheral convex part, 112 Axial groove | channel 112a Inner peripheral inclination part 200 Caulking metal mold 200a Mold surface, 201 hole, 202 Annular convex part 300 Component 310 Tightening plate 320 Nut (female screw member)
D0 Hole diameter D1 of pilot hole 101 D1 outer diameter of ridge 51, D2 inner diameter of ridge 51 D3 inner diameter of annular recess 102, D4 outer diameter of annular recess 102 Da inner diameter Ds of hole 201 outer diameter t of shank 21 metal sheet 101 Thickness T1 Height of the annular convex portion 202

Claims

A stud shaft, a caulking shaft portion extending in an axial direction from the stud portion, and a screw shaft portion extending in an axial direction from an end portion of the caulking shaft portion opposite to the stud portion, the caulking shaft portion being covered. In the fixing structure of the stud bolt and the fixed member that is fixed to the fixing hole of the fixing member, the stud portion protrudes on one surface of the fixed member, and the screw shaft portion protrudes on the other surface.
On the outer periphery of the caulking shaft portion, an axially extending ridge that is fitted into a plurality of axial grooves formed on the inner periphery of the fixing hole of the fixed member is provided,
At the end on the screw shaft portion side of the ridge, a protruding portion that protrudes radially outward and engages with a peripheral edge portion of the fixing hole of the fixed member is provided,

On the peripheral edge of the fixing hole of the fixed member, an annular recess that is locally recessed with the overhang is formed,
The fixing structure of a stud bolt and a member to be fixed, wherein an inner diameter of the annular recess is larger than an inner diameter that is a diameter on a base side of the ridge and smaller than an outer diameter.
The stud portion includes a shank portion that rotatably supports a part, and the shank portion is larger in diameter than an end portion on the shank portion side of the caulking shaft portion, and the caulking shaft of the shank portion. The end on the part side is connected to the caulking shaft portion via a shoulder portion that forms a step, the shoulder portion contacts the fixed member, and the fixed member is connected to the shoulder portion and the overhanging portion. The fixing structure of the stud bolt and to-be-fixed member of Claim 1 which becomes the structure pinched | interposed into an axial direction between.
The stud portion includes a shank portion that rotatably supports a part through a collar, and the diameter of the shank portion is the same as the diameter of the end portion on the shank portion side of the caulking shaft portion. An end surface of the caulking shaft portion side of the collar contacts the fixed member, and the fixed member is configured to be sandwiched between the end surface of the collar on the caulking shaft portion side and the protruding portion in the axial direction. The fixing structure of the stud bolt of Claim 1, and a to-be-fixed member.
The stud bolt according to any one of claims 1 to 3, wherein another clamp plate is further stacked on the fixed member, and the clamp plate is fixed by a female screw component screwed into the screw shaft portion. Fixing structure with fixed member.
A stud bolt having a stud portion, a caulking shaft portion extending in the axial direction from the stud portion, and a screw shaft portion having a male screw extending in the axial direction from an end portion of the caulking shaft portion opposite to the stud portion. In the fixing method of the stud bolt and the fixed member for fixing the fixed member to the fixed member having the fixing pilot hole,
The caulking shaft portion is provided with a plurality of protrusions extending in the axial direction in the circumferential direction,
By inserting the threaded shaft portion of the stud bolt into the pilot hole of the member to be fixed and press-fitting the caulking shaft portion into the inner periphery of the pilot hole of the member to be fixed, the protrusions are bitten into the inner periphery of the pilot hole. ,
By crimping the end of the ridge that protrudes toward the screw shaft side of the pilot hole, a bulge that expands in the radial direction is formed, and the bulge is engaged with the peripheral edge of the pilot hole. ,
Furthermore, the peripheral part of the pilot hole of the fixed member is locally depressed together with the projecting part to form an annular recess,
A fixing method of a stud bolt and a member to be fixed, wherein an inner diameter of the annular recess is larger than an inner diameter that is a diameter on a base side of the ridge and smaller than an outer diameter.
The stud portion includes a shank portion that rotatably supports a part, and the shank portion is larger in diameter than an end portion on the shank portion side of the caulking shaft portion, and the caulking shaft of the shank portion. The end on the part side is connected to the caulking shaft portion via a shoulder portion that forms a step, the shoulder portion contacts the fixed member, and the fixed member is connected to the shoulder portion and the overhanging portion. The fixing method of the stud bolt and to-be-fixed member of Claim 5 which becomes the structure pinched | interposed in an axial direction between.
The stud portion includes a shank portion that rotatably supports a part through a collar, and the diameter of the shank portion is the same as the diameter of the end portion on the shank portion side of the caulking shaft portion. An end surface of the caulking shaft portion side of the collar contacts the fixed member, and the fixed member is configured to be sandwiched between the end surface of the collar on the caulking shaft portion side and the protruding portion in the axial direction. The fixing method of the stud bolt of Claim 5, and a to-be-fixed member.
Caulking of the ridge is performed by a caulking die having a hole through which the screw shaft portion is inserted, and an annular convex portion for forming the annular concave portion is provided at the hole periphery of the caulking die. The fixing method of the stud bolt and the member to be fixed according to any one of claims 5 to 7.
A stud portion, a caulking shaft portion that extends in an axial direction from the stud portion, and is fixed to a prepared hole of a member to be fixed, and a screw shaft that extends in an axial direction from an end portion of the caulking shaft portion opposite to the stud portion A stud bolt having a portion,
A plurality of ridges extending in the axial direction are provided on the outer periphery of the caulking shaft portion in the circumferential direction,
The outer diameter of the ridge is larger than the hole diameter of the pilot hole of the fixed member, and the inner diameter of the base side of the ridge is smaller than the hole diameter of the pilot hole,
The length of the ridge is longer than the thickness of the member to be fixed, and the end on the screw shaft side of the ridge protruding from the member to be fixed is caulked when being fixed to the member to be fixed. The caulking part
A stud bolt characterized in that an inner diameter of the annular recess is larger than an inner diameter which is a diameter on a base side of the ridge, and is smaller than an outer diameter.
The taper part which diameter-reduces so that it may become a small diameter gradually toward the front-end | tip of the said screw shaft part is provided in the edge part by the side of the said screw shaft part of the said crimping shaft part. The stud bolt described in
The portion on the stud portion side of the trough between the ridges is an inclined portion that gradually inclines radially outward toward the stud portion. Stud bolts.
The stud bolt according to any one of claims 9 to 11, wherein the plurality of protrusions provided on the caulking shaft portion are knurled portions.