JP2010071314A - Spring pin and structure for combining two members using this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a functional failure, caused in such a manner that a spring pin interferes with a peripheral member, or that it falls out, by surely preventing the spring pin from slipping out of a pin hole. <P>SOLUTION: In the periphery of spring pin 10, an intermediate section 11b is set to be smaller in diameter than both ends 11a, and diameters of both the ends, when the spring pin becomes a smallest diameter reducible within elastic limit, is set to be smaller than an outer diameter of the intermediate section of the spring pin when it is free without being elastically deformed. Moreover, a chamfering 14 should be provided in tips of both the ends of the spring pin. Furthermore, the first pin hole 20b provided in a first member 20 and second pin holes 21a provided in a second member 21 and roughly equivalent in diameter to a first pin hole 20b, are arranged in order, and both members are combined by inserting the spring pin into these ordered both pin holes. Additionally, a chamfering 20c should be provided in an outer end of pin hole provided in an outer side member. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a spring pin in which a slit extending over the entire length in a longitudinal direction is provided in a part of a circumferential direction of a circular cylindrical member, and a two-member coupling structure using the spring pin.

  As a conventional technique of a two-member coupling structure using this type of spring pin, for example, there are those shown in FIGS. This is a structure in which this type of coupling structure is applied to a shift mechanism of a gear transmission of an automobile, and a lever 1 and a drive shaft 2 are coupled by a spring pin 4. The lever 1 and the drive shaft 2 are engaged with the latter spline 2a in the spline hole 1c formed in the former boss 1a, and springs in the pin holes 1d and 2b formed in alignment with the lever 1 and the drive shaft 2. The pin 4 is inserted and connected. The spring pin 4 is provided with a slit 4a extending over the entire length in the circumferential direction of a circular cylindrical member. By inserting the spring pin 4 into pin holes 1d and 2b having a diameter slightly smaller than the outer diameter, the spring pin 4 is provided. The width of the slit 4a is slightly reduced and the outer diameter is elastically reduced, and the outer peripheral surface of the spring pin 4 is pressed against the inner surface of the pin holes 1d and 2b by a spring reaction force to prevent the friction pin from coming out. ing.

  In this shift mechanism, the tip of a lever portion 1b that is integrally formed with the lever 1 and protrudes in one radial direction is engaged with a U-shaped notch 5a of the shift head 5 that is fixed to the speed change shift shaft. . The operating force from the speed change lever is input as an operating torque to the driving shaft 2 via the arm 3, and this operating torque is transmitted from the driving shaft 2 to the lever 1, from the lever portion 1 b via the notch 5 a and the shift head 5. The transmission gear is transmitted to the transmission shift shaft and the transmission gear is switched.

  Torque transmission from the drive shaft 2 to the lever 1 is performed by the spline engagement between the spline hole 1c and the spline 2a and the spring pin 4 inserted into the pin holes 1d and 2b, but the spline engagement between the spline hole 1c and the spline 2a. Since there is some backlash, the lever 1 and the drive shaft 2 rotate relative to each other, so that the portion of the spring pin 4 inserted into the pin holes 1d and 2b at the boundary between the lever 1 and the drive shaft 2 A shearing force is applied at each operation, and therefore the outer diameter of the spring pin 4 repeats some elastic contraction and restoration. This contraction / restoration causes a slight slip between the outer peripheral surface of the spring pin 4 and the inner surfaces of the pin holes 1d and 2b. When this is repeated for a long time, the spring pin 4 gradually comes out of the pin holes 1d and 2b of the lever 1, The spring pin 4 that has come out may interfere with surrounding members, or may drop out, causing the lever 1 to move in the axial direction with respect to the drive shaft 2, thereby causing a malfunction. In the above, the case where the lever 1 and the drive shaft 2 are spline-engaged and coupled by the spring pin 4 has been described, but the lever 1 and the drive shaft 2 that are fitted to each other without being spline-coupled are coupled only by the spring pin 4. In addition, there arises a problem due to the spring pin 4 coming out as described above. The present invention aims to solve such problems.

  For this reason, the spring pin according to the present invention is provided with a slit covering the entire length in the longitudinal direction in a part of the circumferential direction of the circular cylindrical member, and when a force is applied from the outer peripheral surface, the width of the slit is reduced and the outer diameter is elastic. In a spring pin that shrinks gradually, the outer peripheral surface of the spring pin has a larger outer diameter at its both ends in the longitudinal direction than the outer diameter of the intermediate part located between them, and it shrinks within a range that does not exceed the elastic limit The outer diameter of both ends of the spring pin in a state where the smallest possible diameter is set to be smaller than the outer diameter of the intermediate portion of the spring pin in a free state where it is not elastically deformed It is.

  The spring pin described in the previous section is preferably provided with a chamfer at the tip of at least one of both end portions.

  In addition, the two-member coupling structure using the spring pin according to the present invention includes a first pin hole provided in the first member and a second pin hole provided in the second member and having the same diameter as the first pin hole. Align and align the spring pins whose outer diameter is elastically reduced by reducing the width of the slit if a force is applied from the outer peripheral surface with a slit extending over the entire length in the circumferential direction of a part of the circular cylindrical member. In a two-member coupling structure using a spring pin that couples the two members by inserting them into both pin holes, the outer peripheral surface of the spring pin is positioned between the outer diameters of both ends in the longitudinal direction. The outer diameter of both ends of the spring pin in the state where the outer diameter of the spring pin is larger than the outer diameter of the intermediate portion and the minimum diameter that can be reduced without exceeding the elastic limit is Outside the department The inner diameter of the first or second pin hole is smaller than the outer diameter of the intermediate portion of the spring pin in a free state where it is not elastically deformed, and can be reduced within a range not exceeding the elastic limit. Set larger than the outer diameter of both ends of the spring pin in the state of the minimum diameter, and the length of the intermediate part of the spring pin is the length of the straight part that combines the first and second pin holes in the state of being aligned with each other It is characterized by being set longer than this.

  In the two-member coupling structure using the spring pins described in the preceding paragraph, at least one end of the straight portion where the first and second pin holes are aligned with each other is provided with a subsequent chamfer It is preferable.

  According to the invention of the spring pin according to claim 1, the outer peripheral surface of the spring pin has an outer diameter at its both end portions in the longitudinal direction larger than an outer diameter of the intermediate portion positioned between them, and exceeds the elastic limit. The outer diameter of both ends of the spring pin in a state where the minimum diameter that can be reduced without any range is set to be smaller than the outer diameter of the intermediate portion of the spring pin in a free state where it is not elastically deformed. This spring pin has both ends of the spring pin in a state where the inner diameter is smaller than the outer diameter of the intermediate portion of the spring pin in a free state in which the inner diameter is not elastically deformed and the minimum diameter can be reduced without exceeding the elastic limit. It is used by inserting it into a pin hole that is larger than the outer diameter of the pin and the total length of the straight part is larger than the length of the intermediate part. This spring pin does not shrink beyond the elastic limit when the end of the large diameter portion passes through the pin hole, and the spring pin is elastically restored halfway when inserted into the pin hole. The outer peripheral surface of the intermediate portion, which is a small diameter portion, is elastically contacted with the inner surface of the pin hole, and both end portions of the spring pin that are out of the pin hole have a larger diameter than the intermediate portion. Therefore, unless a very large force is applied, the spring pin does not naturally come out of the pin hole.

  According to the invention of claim 2 in which chamfering is provided at the tip of at least one of both end portions of the spring pin, the mounting of the spring pin into the pin hole is facilitated.

  According to the invention of the two-member coupling structure using the spring pin according to claim 3, the first pin hole provided in the first member and the second member are provided with the same diameter as the first pin hole. The second pin holes are aligned, and a slit extending over the entire length in the longitudinal direction is provided in a part of the circular cylindrical member in the circumferential direction. When force is applied from the outer peripheral surface, the width of the slit is reduced and the outer diameter is elastically reduced. In a two-member coupling structure using a spring pin that couples the two members by inserting the spring pins into the aligned pin holes, the outer peripheral surface of the spring pin has an outer diameter at both ends in the longitudinal direction. The outer diameter of both ends of the spring pin in a state where the outer diameter is larger than the outer diameter of the intermediate portion positioned between and the minimum diameter that can be reduced within a range that does not exceed the elastic limit is in a free state that is not elastically deformed. Spring pin The inner diameter of the first or second pin hole is smaller than the outer diameter of the intermediate part of the spring pin in a free state where it is not elastically deformed and exceeds the elastic limit. The outer diameter of both ends of the spring pin is set larger than the minimum diameter that can be reduced within the range, and the length of the middle portion of the spring pin is set so that the first and second pin holes are aligned with each other. Since it is set longer than the length of the combined straight portion, the spring pin is not reduced beyond the elastic limit when the end portion which is the large diameter portion passes through the first and second pin holes, and When the spring pin is inserted into the pin hole, the spring pin is elastically restored halfway and the outer peripheral surface of the intermediate portion is elastically contacted with the inner surface of the pin hole. Both ends are intermediate . Doing so may and has a large diameter, never get out naturally from the spring pin pin hole as long as the very large force is not applied. Therefore, there is no possibility that the spring pin comes out of the first member and interferes with surrounding members, or falls out of the pin hole and the first member moves relative to the second member, causing a malfunction in function.

  According to the invention of claim 4, a chamfer is provided at the end of at least one of the straight portions where the first and second pin holes are aligned with each other, and the spring pin is inserted into the pin hole. Easy to install.

  First, according to a first embodiment shown in FIGS. 1 and 2, a spring pin according to the present invention and a connecting structure of two members using the same will be described. In this first embodiment, a shaft-like second member 21 (corresponding to the above-described prior art drive shaft 2) is formed in the fitting hole 20a formed in the first member 20 (corresponding to the above-described prior art lever 1). The first pin hole 20b formed in the first member 20 and the second pin hole 21a formed in the second member 21 are aligned, and the spring pin 10 is inserted into both the pin holes 20b, 21 to 20 and 21 are combined. In the first embodiment, unlike the above-described prior art, the first member 20 and the second member 21 are coupled only by the spring pin 10 without spline coupling.

  First, the spring pin 10 of the first embodiment will be described with reference to FIG. The spring pin 10 is provided with a slit 13 extending over the entire length in the longitudinal direction in a part of the cylindrical member having a circular cross-sectional shape. The outer peripheral surface of the spring pin 10 is such that the outer diameter d1 of the end portion 11a positioned at both ends in the longitudinal direction is slightly larger than the outer diameter d2 of the intermediate portion 11b positioned therebetween. The length L1 of 11b occupies most of the entire length of the spring pin 10. The spring pin 10 is a thin steel plate wound in a cylindrical shape and subjected to heat treatment. The small-diameter intermediate portion 11b is formed by cutting or grinding, and chamfered at the ends of both end portions 11a which are both ends in the longitudinal direction of the outer peripheral surface. 14 is provided. In the first embodiment, the diameter of the inner peripheral surface 12 of the spring pin 10 is constant.

  When a force is applied inward from the outer peripheral surface of the spring pin 10, the width of the slit 13 is reduced and the outer diameter is elastically reduced. The outer diameter d1 of the both end portions 11a of the spring pin 10 in a state where the outer diameter becomes the minimum diameter that can be reduced within a range that does not exceed the elastic limit is the outer diameter of the intermediate portion 11b of the spring pin 10 in a free state where the elastic pin is not elastically deformed. It is set to be smaller than the diameter d2.

  As shown in FIG. 2, the first member 20 which is one of the two members to be joined is cylindrical and has a fitting hole 20a formed coaxially and in a cylindrical shape between the outer peripheral surface and the fitting hole 20a. Two first pin holes 20b are coaxially formed along the direction perpendicular to the central axis. The shaft-like second member 21 can be inserted into the fitting hole 20a of the first member 20 with substantially no gap, and a second pin hole 21a orthogonal to the central axis is formed therethrough. Each first pin hole 20b and second pin hole 21a can be coaxially aligned as shown in FIG. 2 (a). Each first pin hole 20b is formed with a chamfer 20c on the outer peripheral side of the first member 20.

  In the first embodiment, the inner diameter d3 of the first pin hole 20b and the inner diameter d4 of the second pin hole 21a are the same, and the value thereof is the outer diameter of the intermediate portion 11b of the spring pin 10 in a free state that is not elastically deformed. It is set to be larger than the outer diameter d1 of both end portions 11a of the spring pin 10 in a state where it is smaller than d2 and has a minimum diameter that can be reduced within a range not exceeding the elastic limit. Each chamfer 20c provided on the outer end side of each first pin hole 20b of the first member 20 has both pin holes in a state where the first pin hole 20b and the second pin hole 21a are aligned as shown in FIG. It is provided following both ends of the straight portion formed by 20b and 21a. The length L1 of the intermediate portion 11b of the spring pin 10 is set to be longer than the length L2 of the straight portion including the aligned pin holes 20b and 21a.

  Next, referring to FIG. 2, the procedure for joining the first member 20 and the second member 21 with the spring pin 10 described above will be described. First, as shown in FIG. 2 (a), the second member 21 is inserted into the fitting hole 20a of the first member 20, and the first pin hole 20b and the second pin hole 21a are aligned. The spring pin 10 is approached from one side in the axial direction of the straight hole formed by 20b and 21a. In the free state in which the spring pin 10 is not elastically deformed, the outer diameter d1 of the both end portions 11a is larger than the inner diameter d3 of the first pin hole 20b of the first member 20, so that it first becomes the tip side in the approaching direction. If the chamfer 14 of the one end portion 11a of the spring pin 10 is brought into contact with the chamfer 20c of the outer end of the first pin hole 20b, and the force is applied to the spring pin 10 to push it further in the axial direction, the chamfer 14 and 20c guide it. Since the outer diameter d1 of the one end 11a of the spring pin 10 is reduced to d3, it is easily inserted into the first pin hole 20b and then inserted into the second pin hole 21a of the second member 21. (See Figure 2 (b)). The inner diameters d3 and d4 of the pin holes 20b and 21a are larger than the outer diameters d1 of both end portions 11a of the spring pin 10 in a state where the minimum diameter can be reduced without exceeding the elastic limit. 10 does not exceed the elastic limit even partly to cause permanent deformation. The chamfers 14 and 15c may be provided only in one of the spring pin 10 and the first pin hole 20b.

  When the spring pin 10 is further pushed in the axial direction, as shown in FIG. 2 (c), the one end portion 11a on the distal end side passes through the straight hole formed by both the pin holes 20b and 21a. The inner diameters d3 and d4 of the pin holes 20b and 21a are smaller than the outer diameter d2 of the intermediate portion 11b of the spring pin 10 in a free state where no elastic deformation occurs, and the length L1 of the intermediate portion 11b of the spring pin 10 is Since the length L2 of the straight hole in which both aligned pin holes 20b and 21a are combined is slightly longer, the spring pin 10 is in a state where the intermediate portion 11b of the spring pin 10 is inserted into the both pin holes 20b and 21a. In addition to being elastically restored halfway and the outer peripheral surface of the intermediate portion 11b being elastically pressed against the inner surfaces of the pin holes 20b and 21a and becoming difficult to move due to friction, the aligned pin holes 20b and 21a Since the outer diameter d1 of both end portions 11a of the spring pin 10 that is out of the straight portion combined with each other is larger than that of the intermediate portion 11b, a very large force is not applied. Ri spring pin 10 is both pin holes 20b, never get out naturally from 21a. Accordingly, the spring pin 10 moves in the axial direction with respect to the pin holes 20b and 21a, and the spring pin 10 that has come out of the first member 20 interferes with surrounding members, causing a malfunction, or the spring pin 10 is dropped off. Thus, there is no fear that the first member 20 moves relative to the second member 21.

  In the above-described first embodiment, the example in which the second member 21 is inserted into the fitting hole 20a of the first member 20 and the both members 20 and 21 are coupled only by the spring pin 10 has been described. 6 and FIG. 7, the second member 21, which is a shaft member, is spline-engaged with the first member 20, and then both the members 20, 21 are connected by the spring pin 10. You may make it combine. Alternatively, a U-shaped notch is formed in the first member 20 in place of the fitting hole 20a, and the shaft-shaped second member 21 is sandwiched in the notch, and formed in both the members 20, 21 respectively. The first and second pin holes may be aligned and coupled by the spring pin 10 as in the first embodiment. In this case, the spring pin 10 is elastically brought into contact with the first pin hole of the first member 20, and the second pin hole so as to be rotatable in the second pin hole of the second member 21. If the inner diameter of the first pin hole is slightly larger than the inner diameter of the first pin hole and a slight gap is provided between the U-shaped notch and the shaft-shaped second member 21, the two members 20 and 21 are shaken with each other. It is combined freely. In any of the above cases, the spring pin 10 does not naturally come out of the pin holes 20b and 21a unless an extremely large force is applied, as in the first embodiment described above. There is no possibility that the first member 20 may come out of the door and interfere with surrounding members, or may fall off and the first member 20 may move relative to the second member 21.

  In the first embodiment described above, the small-diameter intermediate portion 11b on the outer periphery of the spring pin 10 has been described as being formed by cutting or grinding. However, the intermediate portion 11b of the spring pin 10 according to the present invention is not limited thereto, It can also be formed by plastic working. FIG. 3 shows a spring pin 10A of the second embodiment manufactured as described above, and FIGS. 4 and 5 show an apparatus used for processing such a spring pin 10A.

  In the spring pin 10A according to the second embodiment, as shown in FIG. 3, the diameter of the inner peripheral surface 12A and the width of the slit 13A are not constant like the inner peripheral surface 12 and the slit 13 of the first embodiment. The only difference from the first embodiment is that the range corresponding to the intermediate portion 11b of the outer periphery having a small diameter is slightly smaller. Since other structures and shapes are the same as those of the spring pin 10 of the first embodiment, detailed description thereof is omitted.

  As shown in FIG. 4, the material 10B used for manufacturing the spring pin 10A according to the second embodiment is similar to the conventional spring pin 4 shown in FIGS. 6 and 7, and includes the outer peripheral surface 11 and the inner peripheral surface 12A. A circular cylindrical member having a constant diameter and a width of the slit 13A is provided with a slit 13A extending over the entire length in the circumferential direction, and is formed by winding a thin steel plate in a cylindrical shape, The part is provided with a chamfer 14. The diameter of the outer peripheral surface 11 and the inner peripheral surface 12A of the material 10B and the width of the slit 13A are substantially the same as the diameter of the intermediate portion 11b and the inner peripheral surface 12 of the spring pin 10 and the width of the slit 13 of the first embodiment. The same.

  An apparatus for manufacturing the spring pin 10A from the material 10B includes a lower die 30 fixed to the machine frame, an upper die 32 approaching and separating from above the lower die 30, and a pair of punches 34 approaching and separating from both sides. It is configured.

  As shown in FIGS. 4 and 5, an elongated concave semi-cylindrical mold surface 31 is formed on the upper surface of the lower mold 30, and the radius of the mold surface 31 is the same as the radius of the outer peripheral surface 11 of the material 10B. . A low projecting portion 31a for supporting the outer peripheral surface 11 of the spring pin 10A is formed over the length L1 at the center in the longitudinal direction of the mold surface 31. The support surface at the tip of the projecting portion 31a is an arc surface concentric with the mold surface 31, the length is the length L1 of the intermediate portion 11b of the spring pin 10A, and the height is the same as that of the both end portions 11a of the spring pin 10A. This is half of the difference between the outer diameters d1 and d2 of the intermediate portion 11b. On the lower surface of the upper mold 32 which is approached and separated from the lower mold 30 from above, the mold surface 33 and the projecting portion 33a having the same shape and dimensions as the mold surface 31 and the projecting portion 31a of the lower mold 30 are located at positions facing each other. Is formed.

  As shown in FIGS. 4 and 5, each punch 34 includes a cylindrical base portion 34a, a punch body portion 34b and a tip portion 34c that are integrally formed with the punch portion 34 and project in one direction coaxially. The die 30 is disposed coaxially with the central axis of the semi-cylindrical die surface 31 and is provided so as to be close to and away from each other. The diameter of the tip 34c is the same as or slightly smaller than the diameter of the inner peripheral surface 12 of the material 10B, and the diameter of the punch main body 34b is the outer diameter of the end 11a of the spring pin 10A. The diameter is required to expand to d1. The length of the punch body 34b may be slightly shorter than the length of each end 11a of the spring pin 10A, and the length of the tip 34c is arbitrary.

  In order to manufacture the spring pin 10A from the material 10B, first, as shown in FIG. 4, the upper die 32 is lifted and the punches 34 are separated from each other, and on the protruding portion 31a of the die surface 31 of the lower die 30. After placing the material 10B and then lowering the upper mold 32 and holding the material 10B between the projecting portions 31a and 33a of the mold surfaces 31 and 33 of the lower mold 30 and the upper mold 32, the left and right punches 34 are The base 34a is brought close to a position where it abuts against both end faces of the material 10B. Due to this approach, first the leading end 34c of each punch 34 and then the punch body 34b are inserted into the inner peripheral surface 12A of the material 10B, and the outer diameters of both ends of the material 10B abut against both mold surfaces 31 and 33. The spring pin 10A of the second embodiment having both end portions 11a having an outer diameter d2 larger than the outer diameter d1 of the intermediate portion 11b is formed by being spread out so as to come into contact. The heat treatment necessary for the spring pin 10A is performed after this plastic working. The procedure for connecting the first member 20 and the second member 21 by the spring pin 10A of the second embodiment is the same as that described for the spring pin 10 of the first embodiment with reference to FIG.

It is a front view which shows the whole structure of the spring pin by 1st Embodiment of this invention. It is explanatory drawing of the procedure which couple | bonds a 1st member and a 2nd member with the spring pin shown in FIG. It is a front view which shows the whole structure of the spring pin by 2nd Embodiment of this invention. It is sectional drawing seen from the front at the time of the process start of the apparatus used for manufacture of the spring pin shown in FIG. It is sectional drawing seen from the front at the time of the completion | finish of a process of the apparatus shown in FIG. It is a figure which shows an example of the connection structure of 2 members connected with the spring pin of the prior art. It is 7-7 sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,10A ... Spring pin, 11a ... End part, 11b ... Intermediate | middle part, 12, 12A ... Inner peripheral surface, 13, 13A ... Slit, 14 ... Chamfering, 20 ... 1st member, 20b ... 1st pin hole, 21 ... 2nd member, 21a ... 2nd pin hole, d1 ... Outer diameter of end part of spring pin, d2 ... Outer diameter of intermediate part of spring pin, d3 ... Inner diameter of 1st pin hole of 1st member, d4 ... 2nd Inner diameter of second pin hole of member, L1... Length of intermediate portion of spring pin, L2... Length of straight portion including first and second pin holes.

Claims (4)

In the spring pin in which a slit extending over the entire length in the longitudinal direction is provided in a part of the circumferential direction of the circular cylindrical member, and when the force is applied from the outer peripheral surface, the width of the slit is reduced and the outer diameter is elastically reduced.
The outer peripheral surface of the spring pin has an outer diameter of its both end portions in the longitudinal direction larger than the outer diameter of the intermediate portion positioned between them,
The outer diameter of both ends of the spring pin in a state where the diameter can be reduced within a range not exceeding the elastic limit is smaller than the outer diameter of the intermediate portion of the spring pin in a free state where the elastic pin is not elastically deformed. The spring pin is characterized by setting as follows.   2. The spring pin according to claim 1, wherein a chamfer is provided at a tip of at least one of the both end portions. A first pin hole provided in the first member and a second pin hole provided in the second member and having the same diameter as the first pin hole are aligned to form a part of the circular cylindrical member in the circumferential direction. By providing a slit extending over the entire length in the longitudinal direction and inserting a spring pin in which the width of the slit is reduced and the outer diameter is elastically reduced when a force is applied from the outer peripheral surface, the two pins are inserted into the aligned pin holes. In a two-member coupling structure using a spring pin that couples
The outer peripheral surface of the spring pin has an outer diameter of its both end portions in the longitudinal direction larger than the outer diameter of the intermediate portion positioned between them,
The outer diameter of both ends of the spring pin in a state where the diameter can be reduced within a range not exceeding the elastic limit is smaller than the outer diameter of the intermediate portion of the spring pin in a free state where the elastic pin is not elastically deformed. Set as
The inner diameter of the first or second pin hole is smaller than the outer diameter of the intermediate portion of the spring pin in a free state where it is not elastically deformed, and the minimum diameter that can be reduced within a range that does not exceed the elastic limit. Set larger than the outer diameter of both ends of the spring pin,
Further, the length of the intermediate portion of the spring pin is set to be longer than the length of the straight portion in which the first and second pin holes are combined in the state of being aligned with each other. Bond structure.   The two-member coupling structure using the spring pin according to claim 3, wherein at least one end portion of the straight portion in which the first and second pin holes are aligned with each other is continued thereto. A two-member coupling structure using a spring pin, characterized in that chamfering is provided.

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