WO2002021003A1 - Foreign material removing bolt - Google Patents

Foreign material removing bolt Download PDF

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Publication number
WO2002021003A1
WO2002021003A1 PCT/KR2001/001493 KR0101493W WO0221003A1 WO 2002021003 A1 WO2002021003 A1 WO 2002021003A1 KR 0101493 W KR0101493 W KR 0101493W WO 0221003 A1 WO0221003 A1 WO 0221003A1
Authority
WO
WIPO (PCT)
Prior art keywords
bolt
cutting edges
threads
set forth
thread
Prior art date
Application number
PCT/KR2001/001493
Other languages
French (fr)
Inventor
Choon Sik Oh
Original Assignee
Youngsin Metal Industrial Co., Ltd.
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.)
Filing date
Publication date
Priority claimed from KR2020000025071U external-priority patent/KR200226410Y1/en
Priority claimed from KR1020000056194A external-priority patent/KR100807315B1/en
Priority claimed from KR2020010012832U external-priority patent/KR200241800Y1/en
Application filed by Youngsin Metal Industrial Co., Ltd. filed Critical Youngsin Metal Industrial Co., Ltd.
Priority to AU2001286287A priority Critical patent/AU2001286287A1/en
Publication of WO2002021003A1 publication Critical patent/WO2002021003A1/en

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Classifications

    • 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
    • F16B35/00—Screw-bolts; Stay-bolts; Screw-threaded studs; Screws; Set screws
    • F16B35/007—Removing paint or dirt layers covering the threaded part of nut-like members

Definitions

  • the present invention relates, in general, to a bolt and, more particularly, to a bolt for removing foreign material carried between its external threads and the mating threads of a nut or a port, which is prepared to have continuous plastic worked threads with grooves corresponding to a lead portion, and which is provided at its threads with partially angled cutting edges, so that the bolt functions to remove spattered welding particles carried on threads of nuts welded to an objective articles
  • the present invention also relates to a bolt for removing foreign material which is adapted to afford - sufficient fastening capability and desired functions and to assure proper electric conductivity regardless of tightened condition by providing its thread portion with a space or a recess for allowing electrodeposited paint films stripped off. a surface of an automotive part to be collected therein when the bolt is used as a component for fastening automotive parts such as a part connected to an engine .
  • the above type of bolt 10 is generally adapted to be inserted into a through hole formed in an automotive part, for example a fixed panel constituting an engine room (not shown) with a washer interposed therebetween, and screwed into an internal thread portion of a fastening nut welded to the fixed panel .
  • this type of bolt is wholly electrodeposited with paint and then fastened to a fixed panel, which is also wholly electrodeposited with paint in advance, through a through hole formed at the fixed panel by being screwed into a nut.
  • the bolt is caused to be forcibly screwed by a torque exceeding that necessary to strip off paint films electrodeposited to its external threads and internal threads of the nut and to collect foreign material and spattered welding particles carried into the mating area between the threads.
  • Figs. 1 and 2 there are shown the conventional bolt adapted to remove foreign material, which is a hexagonal head bolt or a flange bolt including a head 11 and a shank having a male thread part 13, and which is cut out at two or three regions on its flange and compressed at opposite positions to have two recesses at angular spacing of 180° .
  • the operation of compressing the bolt to have a plurality of recesses may involve frequent breakage of a jig for compressing the bolt.
  • the compressing of the bolt may cause the shank to be deformed to have an elliptical cross section rather than a perfect circular cross- section. Hence, excessive torque is required to tighten the deformed bolt, thereby causing operating efficiency to be lowered.
  • an object of the present invention is to provide a bolt for removing foreign material which is intended to require decreased torque required to tighten the bolt, prevent loosening of the bolt without an additional washer, eliminate spattered welding particles from a mating area between its threaded portion and the corresponding threaded portion, and prevent biting into an internal threaded portion of a nut.
  • Another object of the present invention is to provide a bolt for removing foreign material which is adapted to afford sufficient fastening capability and desired functions and to assure proper electrical conductivity
  • a bolt including external threads having an external diameter corresponding to a root diameter of internal threads of a nut comprising: cutting edges for stripping off and removing paint film, foreign material and spattered welding particles and for increasing its fastening force regardless of tightening direction, which are formed on thread ridges defined by the external diameter of the ridges at regular intervals by rolling dies such that the cutting edges are protruded from the thread ridges.
  • each of the cutting edges is of a triangle when viewed in the longitudinal direction of the bolt. It is preferable that each of the cutting edges is provided at its both sides with bulged portions, each of which has a angle between both the inclined sides of the bulged portion which is smaller than the thread angle of the bolt when viewed in side elevation. It is preferable that the cutting edges are offset at a certain angle ' in a direction such that lines connecting axially adjacent cutting edges are twisted when viewed in side elevation.
  • groove bottoms of the threads are offset at a certain angle in a direction such that lines connecting axially adjacent cutting edges are twisted when viewed in side elevation.
  • Shapes of the cutting edges at the external diameter of the threads may correspond to those of groove bottoms of threads of a nut.
  • a direction- of the twisting of the cutting edges of the threads is selected according to whether the bolt . has left-hand threads or right-hand threads .
  • the number of the cutting edges formed on the thread ridges of the threads is two or more.
  • the head of the bolt may be provided with a polygonal recess (such as a square recess and a hexagonal recess) .
  • Fig. 1 is a schematic view of a conventional bolt
  • Fig. 2 is a cross-sectional view taken along the line A-A of Fig. 1;
  • Fig. 3 is a schematic view of a bolt according to the present invention.
  • Fig. 4 is a perspective view of the bolt according to the present invention
  • Fig. 5 is an enlarged perspective view showing the bolt of Fig. 4 in detail
  • Fig. 6 is an enlarged perspective view showing another embodiment of the bolt of Fig. 4;
  • Fig. 7 is a cross-sectional view taken along the line A-A of Fig. 6; and »
  • Fig. 8 is a schematic view of further embodiment of the bolt of the present invention.
  • FIG. 3 is a s. schematic view of a bolt according to the present invention
  • Fig. 4 is a perspective view of the bolt
  • Fig. 5 is an enlarged perspective view showing the bolt.
  • the reference numeral ⁇ 40" designates a hexagonal head bolt (so called “flange bolt") having a shank 43 formed with a threaded portion 45, which is used to remove electrodeposited paint film, foreign material, spattered welding particles and the like from a mating area between its threaded portion and a corresponding threaded portion of a nut.
  • the bolt is provided at its head end with a polygonal recess (for example, a square recess or a hexagonal recess) 47.
  • the threaded portion 45 of the bolt 40 for removing foreign material is prepared by indenting the shank of the bolt by a tool which is internally provided with successive grooves corresponding to lead portions of the threaded portion 45 having a predetermined thread angle. Since the process for forming the threaded portion of the bolt is substantially equal to the known slide rolling process by typical flat plate dies arranged in parallel, detailed description thereof will be omitted.
  • the threaded portion 45 is provided with two or more cutting edges 51 such that the cutting edges 51 are outwardly protruded from the external diameter of the threaded portion and disposed at radially symmetrical positions when viewed in a cross section.
  • Each of the top portions of the cutting edges 51 is located at a point where the adjacent ridges of the threaded portion 45 meet each other.
  • a cross section defining the root diameter of the threaded portion is circular in shape as in a typical bolt, the threaded portion may be machined to have a hexagonal cross section.
  • Thread ridge 50 of the threaded portion 45 is shaped such that lines connecting equivalent points of adjacent cutting edges are a little twisted in a circumferential direction to be curved when viewed in side elevation.
  • the twisted direction is preferably selected depending on whether the thread ridge 50 runs clockwise or counterclockwise .
  • a groove bottom 60 of the threaded portion 45 is bent in a direction little by little in case of a bolt having a hexagonal cross section, but not necessarily bent in case of a bolt having a circular cross section.
  • the line defined by the groove bottom 60 is bent in a direction little by little toward the lead portion of the bolt.
  • the circle circumscribed within the hexagon defined by the bent points of the groove bottom 60 is concentric with the circle the circle circumscribed within the hexagon defined by the cutting edges 51.
  • the reference numeral "20" designates a washer, which is inserted on the bolt where a diameter of the bolt head is smaller than a hole through which the bolt passes, a surface to be contact with the inner surface of the head is coarse or inclined, or it is necessary to prevent embedding of the head into a soft objective article such as iron material and wood material.
  • a washer 20 is inserted over the shank 45 of the bolt. Thereafter, the bolt is positioned with respect to an objective port such that the axis of the shank of the bolt is aligned with the axis of the objective port, and then tightened by a certain torque. Of course, the bolt is directly screwed into the objective port if the washer 20 is not used. Since the cutting edges 51 are rotated in the nut while being tightly fitted in the groove bottoms of the threads of the nut during tightening of the bolt, the cutting edges 51 strip off a paint film electrodeposited on the threaded portions of the nut and collect foreign material present in the threaded portions while sliding in frictional contact with the threaded portion of the nut.
  • the groove •bottoms 60 of the internal threads of the nut have clearance gaps defined between the thread, ridges of the threads of the nut and for collecting foreign material therein, in which a clearance gap between the groove bottom of the threaded portion of the nut and one straight side of the thread ridge of the ' bolt become large toward the middle portion of the straight side.
  • a bolt for removing foreign material (so called "PC bolt") processed by an indenting process using a metal mold which is produced by continuous, plastic working to have enlarged grooves, each having a maximum width equivalent to a half or a quarter of a pitch of a thread of the mold and positioned to be perpendicular to the lead angle of the thread, has threads which are twisted at an angle corresponding to the lead angle of the thread and has partially angled cutting edges.
  • the peaks of the cutting edge must be intentionally formed into a point by a master design. However, the minimum areas of the peaks generated by master working is allowable.
  • a line defined by the groove bottoms of the threads of the bolt has a circular shape when viewed in cross section.
  • a hexagonal bolt with a flange is suitable in terms of economical efficiency of the conventional technique.
  • the technique for producing the bolt is equal to that for producing a conventional bolt, the exact physical dimensions of the present bolt may vary slightly from those of conventional bolts. The degree of variation must not be more than 0.5% of size of the thread.
  • a indenting depth of the indenting master (not shown, a plate-shaped die can be used) is set to be about 80% of a pitch diameter of the thread, and an internal angle drawn between two lateral faces of the thread is set to be within a range of 60 to 65 ° at a section with the cutting edges, while within a range of 50 to 55° at a section without the cutting edges.
  • the thread of the bolt for removing foreign material is normally cut out by H/5 of a height of the thread at its vertex of a triangle defining the thread in cross section to have a flat face, so that removed foreign material and paint film debris are collected in a gaps between the flat faces of the threads of the bolt and a groove bottoms of threads of a nut.
  • the thread of the bolt may be cut out by H/5.5 of a height thereof.
  • the thread of the bolt may be cut out by H/6 of a height thereof.
  • the thickness of cut out of the thread is controlled depending on amount of spattered welding particles and thickness of paint film.
  • the threads of the bolt must not cause groove bottoms of threads of a nut to be damaged in any event.
  • the present bolt is characterized by this fact as compared with a bolt for improving conductivity. Therefore, the bolt for removing foreign material according to the present invention can be used as an earth bolt.
  • top portions of the threads of a forward end of the bolt can remove foreign material including spattered welding particles during screwing of the bolt into a nut, and subsequent cutting edges 51 radially formed on the whole threads of the bolt repeatedly come into frictional 'contact with threads of a nut, the foreign material including spattered welding particles during screwing of the bolt into a nut, and subsequent cutting edges 51 radially formed on the whole threads of the bolt repeatedly come into frictional 'contact with threads of a nut, the foreign material including spattered welding particles during screwing of the bolt into a nut, and subsequent cutting edges 51 radially formed on the whole threads of the bolt repeatedly come into frictional 'contact with threads of a nut, the foreign
  • the thread ridge portion 50 is sized depending on the difference between the pitch diameter of the thread of the bolt and a root diameter of a thread of a nut, fastening force is easily achieved by frictional contact between threads of the bolt and threads of the nut, and balance of fastening force can be sufficiently assured.
  • the bolt may be alternatively produced in such a manner that a bolt is prepared to have continuous plastic worked threads with grooves corresponding to a lead portion of a typical triangle thread, and the bolt is applied with a ' twisted thread part (geometrical form defined by cutting edges) having thread ridges of.2 to 6 rows of partially angled cutting edges.
  • Such a bolt functions to remove spattered welding particles carried on threads of nuts welded to an objective articles (such as by a robotic welding process) in fields such as automobile and shipbuilding industries, to, strip off electrodeposited paint film to considerably reduce tightening resistance in the automobile and shipbuilding industries (as a bolt for removing foreign material) , and to abrade surfaces of threads of a nut to improve conductivity therebetween and to reduce resistance (as an earth bolt) .
  • the bolt according to the present invention is capable of decreasing torque required to tightening a bolt, and preventing the tightened bolt from being loosened by increasing torque required to loosen the tightened bolt, thereby maximizing its full functions as a bolt.
  • the bolt according to the present invention may have a waved thread ridge line with .cutting edges provided at regular intervals.
  • a bolt according to the present invention is capable of affording sufficient tightening force and electrical conductivity regardless of degree of tightness by providing sufficient fastening force to certain regions of objective parts, and by removing paint film, foreign material and spattered welding particles at several regions and then collecting the removed undesirable material in its gap.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Bolts, Nuts, And Washers (AREA)

Abstract

This invention relates to a bolt for removing foreign materials such as paint film and chip, in which a plurality of cutting edge are formed in succession to a screw part with certain distance and space for collecting foreign material are formed between two adjacent screw parts. When the bolt is screwed in a nut in this condition, the cutting edge of the peripheral edge part of the screw part strips off a paint film by forcing the lateral surface of a screw thread of the nut, and the separated foreign materials are housed in the collecting space. Therefore, the removal of the foreign material is easily made with excellent efficiency.

Description

FOREIGN MATERIAL REMOVING BOLT
Technical Field
The present invention relates, in general, to a bolt and, more particularly, to a bolt for removing foreign material carried between its external threads and the mating threads of a nut or a port, which is prepared to have continuous plastic worked threads with grooves corresponding to a lead portion, and which is provided at its threads with partially angled cutting edges, so that the bolt functions to remove spattered welding particles carried on threads of nuts welded to an objective articles
(such as by a robotic welding process) in fields such as automobile and shipbuilding industries, to strip off electrodeposited paint film to considerably reduce - tightening resistance in the automobile and shipbuilding industries.
Background Art
The present invention also relates to a bolt for removing foreign material which is adapted to afford - sufficient fastening capability and desired functions and to assure proper electric conductivity regardless of tightened condition by providing its thread portion with a space or a recess for allowing electrodeposited paint films stripped off. a surface of an automotive part to be collected therein when the bolt is used as a component for fastening automotive parts such as a part connected to an engine . As illustrated in Fig. 1, the above type of bolt 10 is generally adapted to be inserted into a through hole formed in an automotive part, for example a fixed panel constituting an engine room (not shown) with a washer interposed therebetween, and screwed into an internal thread portion of a fastening nut welded to the fixed panel .
Typically, this type of bolt is wholly electrodeposited with paint and then fastened to a fixed panel, which is also wholly electrodeposited with paint in advance, through a through hole formed at the fixed panel by being screwed into a nut. During the above fastening
' operation, the bolt is caused to be forcibly screwed by a torque exceeding that necessary to strip off paint films electrodeposited to its external threads and internal threads of the nut and to collect foreign material and spattered welding particles carried into the mating area between the threads.
Turning to Figs. 1 and 2, there are shown the conventional bolt adapted to remove foreign material, which is a hexagonal head bolt or a flange bolt including a head 11 and a shank having a male thread part 13, and which is cut out at two or three regions on its flange and compressed at opposite positions to have two recesses at angular spacing of 180° .
As can be seen in Figs. 1 and 2, however, the operation of compressing the bolt to have a plurality of recesses may involve frequent breakage of a jig for compressing the bolt. Also, the compressing of the bolt may cause the shank to be deformed to have an elliptical cross section rather than a perfect circular cross- section. Hence, excessive torque is required to tighten the deformed bolt, thereby causing operating efficiency to be lowered.
Furthermore, because production of the above- mentioned conventional bolt requires an additional cutting operation, the production process of the bolt is complicated. Also, even though one or more spring washers or flat washers are used to prevent the bolt from becoming loose, the procedure of checking the tightened or loosened state of the bolt is not easy.
Further, even when the bolt is sheared or misaligned with respect to the axis of a mating threaded port, it is difficult to detect any abnormality while tightening the bolt. Even if an abnormality is found, the bolts must be inspected one by one by means of a gauge to reuse the bolts. That is, it is difficult to achieve perfect bolt, and quality management for bolts requires prohibitive costs. Disclosure of the Invention
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a bolt for removing foreign material which is intended to require decreased torque required to tighten the bolt, prevent loosening of the bolt without an additional washer, eliminate spattered welding particles from a mating area between its threaded portion and the corresponding threaded portion, and prevent biting into an internal threaded portion of a nut.
Another object of the present invention is to provide a bolt for removing foreign material which is adapted to afford sufficient fastening capability and desired functions and to assure proper electrical conductivity
- regardless of degree of tighteness by providing its thread portion with a space or a recess for allowing electrodeposited paint films striped off a surface of an automotive part to be collected therein when it is used as a component for fastening an automotive part such as a part connected to an automotive engine.
In order to accomplish the above object, the present invention provides A bolt including external threads having an external diameter corresponding to a root diameter of internal threads of a nut, comprising: cutting edges for stripping off and removing paint film, foreign material and spattered welding particles and for increasing its fastening force regardless of tightening direction, which are formed on thread ridges defined by the external diameter of the ridges at regular intervals by rolling dies such that the cutting edges are protruded from the thread ridges.
It is preferable that the shape of each of the cutting edges is of a triangle when viewed in the longitudinal direction of the bolt. It is preferable that each of the cutting edges is provided at its both sides with bulged portions, each of which has a angle between both the inclined sides of the bulged portion which is smaller than the thread angle of the bolt when viewed in side elevation. It is preferable that the cutting edges are offset at a certain angle 'in a direction such that lines connecting axially adjacent cutting edges are twisted when viewed in side elevation.
It is preferable that groove bottoms of the threads are offset at a certain angle in a direction such that lines connecting axially adjacent cutting edges are twisted when viewed in side elevation.
Shapes of the cutting edges at the external diameter of the threads may correspond to those of groove bottoms of threads of a nut.
It is preferable that a direction- of the twisting of the cutting edges of the threads is selected according to whether the bolt . has left-hand threads or right-hand threads .
It is preferable that the number of the cutting edges formed on the thread ridges of the threads is two or more. The head of the bolt may be provided with a polygonal recess (such as a square recess and a hexagonal recess) .
Brief Description of the Drawings
Fig. 1 is a schematic view of a conventional bolt; Fig. 2 is a cross-sectional view taken along the line A-A of Fig. 1;
Fig. 3 is a schematic view of a bolt according to the present invention;
Fig. 4 is a perspective view of the bolt according to the present invention; - " Fig. 5 is an enlarged perspective view showing the bolt of Fig. 4 in detail;
Fig. 6 is an enlarged perspective view showing another embodiment of the bolt of Fig. 4;
Fig. 7 is a cross-sectional view taken along the line A-A of Fig. 6; and »
Fig. 8 is a schematic view of further embodiment of the bolt of the present invention.
Best Mode for Carrying Out the Invention Fig. 3 is a s. schematic view of a bolt according to the present invention, Fig. 4 is a perspective view of the bolt, and Fig. 5 is an enlarged perspective view showing the bolt. The reference numeral ΛΛ40" designates a hexagonal head bolt (so called "flange bolt") having a shank 43 formed with a threaded portion 45, which is used to remove electrodeposited paint film, foreign material, spattered welding particles and the like from a mating area between its threaded portion and a corresponding threaded portion of a nut. The bolt is provided at its head end with a polygonal recess (for example, a square recess or a hexagonal recess) 47.
The threaded portion 45 of the bolt 40 for removing foreign material is prepared by indenting the shank of the bolt by a tool which is internally provided with successive grooves corresponding to lead portions of the threaded portion 45 having a predetermined thread angle. Since the process for forming the threaded portion of the bolt is substantially equal to the known slide rolling process by typical flat plate dies arranged in parallel, detailed description thereof will be omitted.
The threaded portion 45 is provided with two or more cutting edges 51 such that the cutting edges 51 are outwardly protruded from the external diameter of the threaded portion and disposed at radially symmetrical positions when viewed in a cross section. Each of the top portions of the cutting edges 51 is located at a point where the adjacent ridges of the threaded portion 45 meet each other.
Though it is preferable that a cross section defining the root diameter of the threaded portion is circular in shape as in a typical bolt, the threaded portion may be machined to have a hexagonal cross section.
Thread ridge 50 of the threaded portion 45 is shaped such that lines connecting equivalent points of adjacent cutting edges are a little twisted in a circumferential direction to be curved when viewed in side elevation.
The twisted direction is preferably selected depending on whether the thread ridge 50 runs clockwise or counterclockwise . A groove bottom 60 of the threaded portion 45 is bent in a direction little by little in case of a bolt having a hexagonal cross section, but not necessarily bent in case of a bolt having a circular cross section.
In other words, the line defined by the groove bottom 60 is bent in a direction little by little toward the lead portion of the bolt.
The circle circumscribed within the hexagon defined by the bent points of the groove bottom 60 is concentric with the circle the circle circumscribed within the hexagon defined by the cutting edges 51.
Referring again to Fig. 1, the reference numeral "20" designates a washer, which is inserted on the bolt where a diameter of the bolt head is smaller than a hole through which the bolt passes, a surface to be contact with the inner surface of the head is coarse or inclined, or it is necessary to prevent embedding of the head into a soft objective article such as iron material and wood material. A tightening operation of the bolt according to the present invention will now be described.
First, a washer 20 is inserted over the shank 45 of the bolt. Thereafter, the bolt is positioned with respect to an objective port such that the axis of the shank of the bolt is aligned with the axis of the objective port, and then tightened by a certain torque. Of course, the bolt is directly screwed into the objective port if the washer 20 is not used. Since the cutting edges 51 are rotated in the nut while being tightly fitted in the groove bottoms of the threads of the nut during tightening of the bolt, the cutting edges 51 strip off a paint film electrodeposited on the threaded portions of the nut and collect foreign material present in the threaded portions while sliding in frictional contact with the threaded portion of the nut.
At this point, the stripped paint film debris and the foreign material are collected in clearance gaps between groove bottoms of the threads of the nut and the thread ridges 50 of the threaded portion of the bolt.
As shown in Fig. 6, the groove •bottoms 60 of the internal threads of the nut have clearance gaps defined between the thread, ridges of the threads of the nut and for collecting foreign material therein, in which a clearance gap between the groove bottom of the threaded portion of the nut and one straight side of the thread ridge of the' bolt become large toward the middle portion of the straight side.
A bolt for removing foreign material (so called "PC bolt") processed by an indenting process using a metal mold which is produced by continuous, plastic working to have enlarged grooves, each having a maximum width equivalent to a half or a quarter of a pitch of a thread of the mold and positioned to be perpendicular to the lead angle of the thread, has threads which are twisted at an angle corresponding to the lead angle of the thread and has partially angled cutting edges. The peaks of the cutting edge must be intentionally formed into a point by a master design. However, the minimum areas of the peaks generated by master working is allowable.
It is preferable that a line defined by the groove bottoms of the threads of the bolt has a circular shape when viewed in cross section.
A hexagonal bolt with a flange is suitable in terms of economical efficiency of the conventional technique.
Though the technique for producing the bolt is equal to that for producing a conventional bolt, the exact physical dimensions of the present bolt may vary slightly from those of conventional bolts. The degree of variation must not be more than 0.5% of size of the thread.
In this case, a indenting depth of the indenting master (not shown, a plate-shaped die can be used) is set to be about 80% of a pitch diameter of the thread, and an internal angle drawn between two lateral faces of the thread is set to be within a range of 60 to 65 ° at a section with the cutting edges, while within a range of 50 to 55° at a section without the cutting edges.
The thread of the bolt for removing foreign material is normally cut out by H/5 of a height of the thread at its vertex of a triangle defining the thread in cross section to have a flat face, so that removed foreign material and paint film debris are collected in a gaps between the flat faces of the threads of the bolt and a groove bottoms of threads of a nut.
When amount■ of paint film debris and foreign material are not too great, the thread of the bolt may be cut out by H/5.5 of a height thereof. When an electrodeposited paint film is thin or resistance to tightening of the bolt is extremely low, the thread of the bolt may be cut out by H/6 of a height thereof. The thickness of cut out of the thread is controlled depending on amount of spattered welding particles and thickness of paint film. However, the threads of the bolt must not cause groove bottoms of threads of a nut to be damaged in any event. The present bolt is characterized by this fact as compared with a bolt for improving conductivity. Therefore, the bolt for removing foreign material according to the present invention can be used as an earth bolt. In this case, since removed paint film and foreign material are collected in crescent shaped gaps between groove bottoms 60 of internal threads of a nut and the upper faces of the threads of the bolt when viewed in cross section, the top portions of the cutting edges 51 and groove bottoms of threads of a nut 60 are in close contact with each other without paint film therebetween, thereby affording improved electrical conductivity.
Since the top portions of the threads of a forward end of the bolt can remove foreign material including spattered welding particles during screwing of the bolt into a nut, and subsequent cutting edges 51 radially formed on the whole threads of the bolt repeatedly come into frictional 'contact with threads of a nut, the foreign
' material and spattered welding particles existing on internal threads of a nut can be completely removed when tightening of the bolt is concluded. Where the cutting edge 51 and the groove bottom of the thread of the shank are formed to have a polygonal cross section, points where the threads of the bolt come into contact with groove bottoms or inner walls of threads of a nut are not located in an axial straight line because lines connecting the adjacent cutting edges 51 are twisted. Hence, frictional force acting on the nut is dispersed, so that breakage of mating nuts and bolts are prevented and the .tightening of the bolt can be achieved by relatively low torque.
After the tightening of the bolt, since the thread ridge portion 50 is sized depending on the difference between the pitch diameter of the thread of the bolt and a root diameter of a thread of a nut, fastening force is easily achieved by frictional contact between threads of the bolt and threads of the nut, and balance of fastening force can be sufficiently assured. Though the cutting edges have been disclosed as being provided at all the threads of the bolt in the above description, the bolt may be alternatively produced in such a manner that a bolt is prepared to have continuous plastic worked threads with grooves corresponding to a lead portion of a typical triangle thread, and the bolt is applied with a' twisted thread part (geometrical form defined by cutting edges) having thread ridges of.2 to 6 rows of partially angled cutting edges. Such a bolt functions to remove spattered welding particles carried on threads of nuts welded to an objective articles (such as by a robotic welding process) in fields such as automobile and shipbuilding industries, to, strip off electrodeposited paint film to considerably reduce tightening resistance in the automobile and shipbuilding industries (as a bolt for removing foreign material) , and to abrade surfaces of threads of a nut to improve conductivity therebetween and to reduce resistance (as an earth bolt) . Furthermore, where the bolt according to the present invention is used to fasten automotive parts after a welding process of nuts for automotive parts followed by a painting process, or to fasten assembly parts subjected to tapping processes in general industry and shipbuilding industry, etc., and to fasten welded parts in general industry and shipbuilding industry, etc., the bolt of the present invention is capable of decreasing torque required to tightening a bolt, and preventing the tightened bolt from being loosened by increasing torque required to loosen the tightened bolt, thereby maximizing its full functions as a bolt.
As shown in Fig. 8, the bolt according to the present invention may have a waved thread ridge line with .cutting edges provided at regular intervals.
Industrial Applicability
As described above, a bolt according to the present invention is capable of affording sufficient tightening force and electrical conductivity regardless of degree of tightness by providing sufficient fastening force to certain regions of objective parts, and by removing paint film, foreign material and spattered welding particles at several regions and then collecting the removed undesirable material in its gap.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

Claims
1. A bolt including external threads having an external diameter corresponding to a root diameter of internal threads of a nut, comprising: cutting edges for stripping off and removing paint film, foreign material and spattered welding particles and for increasing its fastening force regardless of tightening direction, which are formed on thread ridges defined by the external diameter of the ridges at regular intervals by rolling dies such that the cutting edges are protruded from the thread ridges.
2. The bolt as set forth in claim 1, wherein the shape of each of the cutting edges is of a frusto-triangle when viewed in the longitudinal direction of the bolt.
3. The bolt as set forth in claim 1, wherein each of the cutting edges is provided at its both sides with bulged portions, each of which has a angle between both the inclined sides of the bulged portion which is smaller than the thread angle of the . bolt when viewed in side elevation.
4. The bolt as set forth in claim 1, wherein the cutting edges are offset at a certain angle in a direction such that lines connecting axially adjacent cutting edges are twisted when viewed in side elevation.
5. The bolt as set forth in claim 3, wherein groove bottoms of the threads offset at a certain angle in a direction such • that lines connecting axially adjacent cutting edges are twisted when viewed in side elevation.
6. The bolt as set forth in claim 4 or 5, wherein shapes of the cutting edges at the external diameter of the threads correspond to those of groove bottoms of threads of a nut.
7. The bolt as set forth in claim 1 or 5, wherein a direction of the twisting of the cutting edges of . the threads is selected according to whether the bolt has left-hand threads or right-hand threads .
8. The bolt as set forth in claim 1 or 5, wherein the number of the cutting edges formed on the thread ridges of the threads is two or more.
9. The bolt as set forth in claim 1, wherein an internal angle drawn between two lateral faces of the thread is set to be within a range of 60 to 65° at a section with the cutting edges, while within a range of 50 to 55° at a section without the cutting edges.
10. The bolt .as set forth in claim 1, wherein the threads on the section without the cutting edges are provided in a predetermined number from the head and in a predetermined lead angle.
PCT/KR2001/001493 2000-09-04 2001-09-04 Foreign material removing bolt WO2002021003A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2001286287A AU2001286287A1 (en) 2000-09-04 2001-09-04 Foreign material removing bolt

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
KR2000/25071U 2000-09-04
KR2020000025071U KR200226410Y1 (en) 2000-09-04 2000-09-04 Earth bolt
KR1020000056194A KR100807315B1 (en) 2000-09-25 2000-09-25 Earth bolt
KR2000/56194 2000-09-25
KR2020010012832U KR200241800Y1 (en) 2001-05-03 2001-05-03 Foreign material removing bolt
KR2001/12832U 2001-05-03

Publications (1)

Publication Number Publication Date
WO2002021003A1 true WO2002021003A1 (en) 2002-03-14

Family

ID=27350234

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2001/001493 WO2002021003A1 (en) 2000-09-04 2001-09-04 Foreign material removing bolt

Country Status (2)

Country Link
AU (1) AU2001286287A1 (en)
WO (1) WO2002021003A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49143671U (en) * 1973-04-12 1974-12-11
JPS52154563A (en) * 1976-06-17 1977-12-22 Meiji Milk Prod Co Ltd Production of liquid cake mix
JPH05141407A (en) * 1991-11-14 1993-06-08 Toopura:Kk Screw

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49143671U (en) * 1973-04-12 1974-12-11
JPS52154563A (en) * 1976-06-17 1977-12-22 Meiji Milk Prod Co Ltd Production of liquid cake mix
JPH05141407A (en) * 1991-11-14 1993-06-08 Toopura:Kk Screw

Also Published As

Publication number Publication date
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