Method for manufacturing eye joint with Anti-rotation pin

Abstract

To provide a method for manufacturing an eye joint with an anti-rotation pin capable of reducing a manufacturing cost while maintaining conventional functions.SOLUTION: A method for manufacturing an eye joint 100A with an anti-rotation pin comprises: a protrusion forming process for forming a protrusion 2b on a side surface of an end part of an anti-rotation pin 2; a component arrangement process for arranging an eye joint 1A and the anti-rotation pin 2 so that the protrusion 2b contacts an outer peripheral surface of an annular part 12; and a welding process for resistance-welding the protrusion 2b to the outer peripheral surface of the annular part 12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a locking pin eye joint. [Background technology]

[0002] For example, the brakes of an automobile are activated by converting pedal force into hydraulic pressure, which is then transmitted through brake hoses to brake calipers. Such brake hoses generally have an eye joint attached to the end, which connects them to the brake calipers.

[0003] An eye joint is generally fixed with a bolt inserted through its annular portion. To prevent the eye joint from rotating when fixed with this bolt, it is known to provide a locking pin on the annular portion of the eye joint (see, for example, Patent Document 1). In Patent Document 1, one end of the locking pin (e.g., locating pin 28A in Patent Document 1) is inserted and fixed in a recess formed on the side of the annular portion of the eye joint. The locking pin is also bent, and the other end is inserted into a locating hole formed in the object to be fixed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-112618 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the conventional method described above, it is necessary to perform, for example, a step of forming a recess on the side of the annular portion of the eye joint, a step of press-fitting and brazing the anti-rotation pin into the recess, and a step of bending the anti-rotation pin. The anti-rotation pin is connected to the eye joint through these steps. However, this method is time-consuming and increases manufacturing costs.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for manufacturing an eye joint with a locking pin that can reduce manufacturing costs while maintaining conventional functionality. [Means for solving the problem]

[0007] The method for manufacturing an eye joint with an anti-rotation pin of the present invention is a method for manufacturing an eye joint with an anti-rotation pin that is formed by combining an eye joint that has a cylindrical portion or pipe connection portion at its end and a circular portion, and an anti-rotation pin, and includes a protrusion forming process that forms a protrusion on the side of the end of the anti-rotation pin, a component placement process that positions the eye joint and the anti-rotation pin so that the protrusion contacts the outer peripheral surface of the circular portion, and a welding process that resistance welds the protrusion to the outer peripheral surface. [Effects of the Invention]

[0008] According to the present invention, resistance welding is performed with a protrusion formed on the side end of the anti-rotation pin in contact with the outer circumferential surface of the annular portion of the eye joint. During the welding process, the main body of the anti-rotation pin is separated from the annular portion by the protrusion. Therefore, even if the protrusion in contact with the annular portion melts during resistance welding, the anti-rotation pin and the annular portion are prevented from coming too close to each other or from sinking into the main body of the anti-rotation pin. As a result, interference between the anti-rotation pin and its molten material and bolts inserted into the annular portion is reduced, thereby maintaining conventional functionality. Furthermore, conventional processes such as forming a recess on the side of the annular portion of the eye joint, press-fitting the anti-rotation pin into the recess and brazing it, and bending the anti-rotation pin can be omitted, thereby reducing manufacturing costs. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an example of an eye joint 100A with a locking pin. [Figure 2] 1 is a vertical cross-sectional side view showing an example of an eye joint 100A with a locking pin. [Figure 3] FIG. 10 is a top view showing an example of an eye joint 100B with a locking pin. [Figure 4A] FIG. 2 is a top view showing an example of a locking pin 2A. [Figure 4B] FIG. 2 is a side view showing an example of a locking pin 2A. [Figure 5A] FIG. 10 is a top view showing an example of a locking pin 2B. [Figure 5B] FIG. 10 is a side view showing an example of a locking pin 2B. [Figure 6] 1A and 1B are an exploded perspective view of the arrangement jig and an explanatory diagram showing the arrangement positions of an eye joint 1B and a locking pin 2 relative to the arrangement jig in the component arrangement process. [Figure 7] 10 is an explanatory diagram showing the positional relationship between the arrangement jig, the eye joint 1B, the anti-rotation pin 2, and the welding electrode. FIG. [Figure 8]10 is a diagram showing the state in which the locking pin eye joint 100B is installed on the torque test jig 3 when measuring the strength of the locking pin. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] (Configuration of 100A eye joint with anti-rotation pin) As shown in FIG. 1, an eye joint with a rotation-preventing pin 100A of this embodiment is formed by combining an eye joint 1A and a rotation-preventing pin 2.

[0012] (Eye Joint 1A) As shown in FIGS. 1 and 2, the eye joint 1A has a socket 11 as a cylindrical portion, an annular portion 12, a neck portion 13, and a nipple 14.

[0013] The socket 11 is provided at one end of the eye joint 1A. The socket 11 has an insertion portion 11a provided therein (see FIG. 2). The insertion portion 11a provided therein has a tubular shape. The socket 11 and the insertion portion 11a have the same axis.

[0014] The annular portion 12 is provided at the other end of the eye joint 1A. The annular portion 12 is an annular member having through holes 12b through which bolts for fixing are inserted. The annular portion 12 has a driving hole 12a (see FIG. 2) that penetrates the side wall surface of the annular portion 12, approximately in the center between its upper and lower surfaces. The tip of the neck portion 13 is driven into the driving hole 12a, and the parts are joined by copper brazing.

[0015] Neck portion 13 is formed integrally with socket 11, has a cylindrical shape that is thinner than socket 11, and has a communication hole 13a (see FIG. 2) formed therein. As described above, the tip of neck portion 13 is driven into driving hole 12a of annular portion 12, thereby connecting socket 11 and annular portion 12.

[0016] Nipple 14 is a cylindrical member whose outer diameter is formed to match the communicating hole 13a, and has fluid hole 14a formed therein. The tip of nipple 14 is driven into communicating hole 13a, and this location is joined by copper brazing. As a result, fluid hole 14a of nipple 14 communicates with through-hole 12b formed in annular portion 12 via communicating hole 13a. Furthermore, because socket 11 is configured into a socket shape by joining nipple 14, it becomes possible to insert and connect a hose such as a brake hose into insertion portion 11a.

[0017] The socket 11, annular portion 12, neck portion 13, and nipple 14 are configured so that the axis of the insertion portion 11a provided in the socket 11, the axis of the driving hole 12a provided in the annular portion 12 and the axis of the communicating hole 13a provided in the neck portion 13, and the axis of the fluid hole 14a provided in the nipple 14 coincide with each other.

[0018] The shape of eye joint 1A is not limited as long as it does not pose a problem in practical use in a hydraulic brake system. The material of eye joint 1A is, for example, carbon steel. Specifically, the material of eye joint 1A is carbon steel containing 0.10% by weight or more and 0.15% by weight or less of carbon. More specifically, the material of eye joint 1A is cold heading carbon steel SWCH12A or SWCH12R. However, the material is not limited to these, and any material may be used for eye joint 1A as long as it does not pose a problem in practical use in a hydraulic brake system.

[0019] The above-described eye joint 1A is attached to the end of a hose such as a brake hose (not shown). For example, the end of the brake hose is inserted into socket 11, and while the brake hose is held in place by nipple 14 provided inside socket 11, socket 11 is crimped to reduce the diameter, thereby attaching eye joint 1A to the end of the brake hose.

[0020] The eye joint is not limited to being used for attaching a hose as described above, and may also be used for connecting pipes, for example. Specifically, the present invention may be applied to a manufacturing method for an eye joint with a locking pin 100B using an eye joint for connecting pipes 1B shown in FIG. 3. As shown in FIG. 3, eye joint 1B has an annular portion 12 and a cylindrical pipe connection portion 15. One end of pipe connection portion 15 is integrally formed with annular portion 12, and the other end is connected to pipe 16. Pipe connection portion 15 and pipe 16 can be connected, for example, by brazing. Pipe 16 can be made of, for example, a double-wrapped steel pipe. Furthermore, when connecting a socket to the end of pipe 16, the method described in Japanese Patent No. 6906230 can be used. Below, we will explain an eye joint with a locking pin 100B that uses eye joint 1B as an eye joint.

[0021] (Anti-rotation pin 2) Anti-rotation pin 2 is attached to eye joint 1B, for example, to prevent rotation when eye joint 1B is bolted. Anti-rotation pin 2 is provided on the outer circumferential surface of annular portion 12. As shown in FIGS. 1 and 2, anti-rotation pin 2 has a cylindrical main body 2a and a protrusion 2b formed on the side of the end portion. This protrusion 2b is resistance welded to the outer circumferential surface of annular portion 12, thereby joining anti-rotation pin 2 to eye joint 1B.

[0022] In this embodiment, the anti-rotation pin 2 is provided at a position facing the pipe connection portion 15 with respect to the eye joint 1B, but this is not limiting. Furthermore, the main body portion 2a is cylindrical, but may be prismatic. Furthermore, the main body portion 2a is attached at an angle parallel to the penetrating direction of the annular portion 12, but this is not limiting. The shape and attachment angle of the main body portion 2a may be changed depending on the shape of a positioning hole provided in the attachment target of the eye joint 1B.

[0023] In this embodiment, the material of the anti-rotation pin 2 is carbon steel containing 0.42% by weight or more and 0.48% by weight or less of carbon. More specifically, the material of the anti-rotation pin 2 is SWCH45K, a cold heading carbon steel. In this way, the anti-rotation pin 2 uses carbon steel containing a higher carbon content than the eye joint 1B, but is not limited to this material. For example, carbon steel such as SWCH12A containing the same carbon content as the eye joint 1B may be used.

[0024] 2, the thickness H1 of the protrusion 2b in the axial direction of the anti-rotation pin 2 is configured to be smaller than the thickness H2 of the annular portion 12. The protrusion 2b is disposed inside both ends of the annular portion 12 in the axial direction. In this way, the protrusion 2b is configured not to protrude in the thickness direction of the annular portion 12, which reduces the possibility of the protrusion 2b interfering with the bolt or the object to be attached when attaching the eye joint 1B.

[0025] As shown in FIG. 3, protrusion 2b of anti-rotation pin 2 is formed in a ring shape when viewed from the axial direction of anti-rotation pin 2. As shown in FIG. 2, protrusion 2b of anti-rotation pin 2 is formed in a mountain shape when viewed from the side of anti-rotation pin 2. This allows contact with annular portion 12 at any position on the ring, making it easy to position anti-rotation pin 2 relative to eye joint 1B. Furthermore, because protrusion 2b is formed in both a ring shape and a mountain shape, protrusion 2b can come into point contact with annular portion 12. This increases the resistance at this contact point, enabling efficient resistance welding.

[0026] (Modification of the anti-rotation pin 2) The shape of the protrusion 2b of the anti-rotation pin 2 is not limited to this. For example, as shown in FIG. 4A, the protrusion 2bA of the anti-rotation pin 2A is formed in a ring shape when viewed from the axial direction of the anti-rotation pin 2. As shown in FIG. 4B, the protrusion 2bA is formed in an area that does not include the end face of the anti-rotation pin 2. As described above, the protrusion 2bA of the anti-rotation pin 2A is formed in a mountain shape when viewed from the side of the anti-rotation pin 2A. By forming the protrusion 2bA midway along the main body 2a in this way, it becomes easier to support both ends of the main body 2a and stabilize its positioning relative to the eye joint 1B, for example, during a welding process.

[0027] As shown in FIGS. 5A and 5B, a tapered protrusion 2bB is formed on the side of the anti-rotation pin 2B. A second protrusion 2bB2 having a flat portion 2bB3 is formed on the side of the anti-rotation pin 2B opposite the protrusion 2bB1. As shown in FIG. 5A, in this modification, the shape formed by the protrusion 2bB1 and the second protrusion 2bB2 is substantially pentagonal when viewed from the axial direction of the anti-rotation pin 2B. That is, the flat portion 2bB3 is formed on the side opposite the corner of the protrusion 2bB1. This allows the electrode terminal to be stably pressed against the flat portion 2bB3 during the welding process. Furthermore, by welding the tapered protrusion 2bB1 in contact with the annular portion 12, the resistance value at this contact point can be increased, enabling efficient resistance welding.

[0028] (Manufacturing method of the eye joint 100B with anti-rotation pin: protrusion forming process) Next, a method for manufacturing the above-described anti-rotation pin eye joint 100B is described. First, a protrusion forming step is performed in which protrusion 2b is formed on the side surface of the end of anti-rotation pin 2. In the protrusion forming step, protrusion 2b may be formed on main body 2a, or anti-rotation pin 2 including main body 2a and protrusion 2b may be formed simultaneously. For example, although not shown, forging may be performed using a split die that is split at the most protruding point of protrusion 2b.

[0029] (Manufacturing method of eye joint 100B with anti-rotation pin: Part placement process) Next, a component placement process is performed in which the eye joint 1B and the anti-rotation pin 2 are placed so that the protrusion 2b contacts the outer peripheral surface of the annular portion 12. For example, in this embodiment, a placement jig is used in the component placement process. The placement jig used in the component placement process of this embodiment will be specifically described below.

[0030] (Example of component placement process) 6, the arrangement jig is composed of an arrangement jig main body 40 and a pin jig 50. The arrangement jig main body 40 is used to fix the annular portion 12 and the pipe connection portion 15 in the component arrangement process. The pin jig 50 is used to position the anti-rotation pin 2 relative to the annular portion 12 in the component arrangement process.

[0031] (Example of component placement process: placement jig body 40) The arrangement jig body 40 has a first cavity 61, a second cavity 62, a third cavity 63, and a fourth cavity 64 inside. The first cavity 61 is a space for arranging the annular portion 12 and the pipe connection portion 15. The second cavity 62 is a space for arranging the pin jig 50. The third cavity 63 is a space for arranging an electrode for resistance welding (for example, an annular portion-side electrode rod 70 described below). The fourth cavity 64 is a space for abutting the anti-rotation pin 2 arranged in the pin jig 50 against the annular portion 12.

[0032] As shown in FIG. 6 , the arrangement jig body 40 is a split-mold jig and includes a first arrangement jig body 41 and a second arrangement jig body 42. Symmetrical fitting holes are formed in the abutment surfaces 40a of the first arrangement jig body 41 and the second arrangement jig body 42, where they abut against each other. When the first arrangement jig body 41 and the second arrangement jig body 42 abut against each other, the symmetrical fitting holes form a first cavity 61 and a second cavity 62. Note that, in this embodiment, the arrangement jig body 40 is formed in a split-mold shape having the first arrangement jig body 41 and the second arrangement jig body 42; however, the arrangement jig body 40 may have any shape that allows the annular portion 12 and the pipe connection portion 15 to be arranged therein; this is not limiting.

[0033] The first arrangement jig body 41 and the second arrangement jig body 42 have abutment surfaces 40a that abut against each other. The annular portion 12 and the pipe connection portion 15 are placed in a first cavity 61 formed in the abutment surfaces 40a. The annular portion 12 and the pipe connection portion 15 are placed in the first cavity 61 so that the axial direction of the through hole 12b in the annular portion 12 coincides with the direction in which the first arrangement jig body 41 and the second arrangement jig body 42 abut against each other.

[0034] Hereinafter, the direction in which the first placement jig body 41 and the second placement jig body 42 are abutted is referred to as the front-rear direction X. In the front-rear direction X, the side on which the first placement jig body 41 is located is referred to as the front side X1, and the side on which the second placement jig body 42 is located is referred to as the rear side X2. Furthermore, the axial direction of the cylindrical pipe connection portion 15 of the eye joint 1B is referred to as the up-down direction Z. In the up-down direction Z, the direction from the pipe connection portion 15 toward the annular portion 12 in the up-down direction Z is referred to as the upper side Z1, and the opposite side is referred to as the lower side Z2. Furthermore, the direction perpendicular to both the front-rear direction X and the up-down direction Z is referred to as the lateral direction Y.

[0035] As shown in the upper left of FIG. 6 , the fitting hole in the arrangement jig main body 40 forms a first cavity 61 and a fourth cavity 64 that communicates with an upper side Z1 of the first cavity 61. The annular portion 12 and the pipe connection portion 15 are fitted into the first cavity 61. When the annular portion 12 and the pipe connection portion 15 are fitted into the first cavity 61, a portion of the upper side Z1 of the annular portion 12 protrudes into the fourth cavity 64. A pin jig 50 is placed in a second cavity 62, which is a space on the rear side X2 that communicates with the fourth cavity 64. The second cavity 62 penetrates to the upper side Z1 of the arrangement jig main body 40 so that the pin jig 50 can be placed from the upper side Z1 of the arrangement jig main body 40. In addition, only one hole (the fitting hole of the first arrangement jig body 41) of a pair of fitting holes having symmetrical shapes is shown in the upper left part of FIG.

[0036] On the contact surface 40a, a pin hole 412 is provided in the first arrangement jig body 41, and a positioning pin 422 is provided at the opposing position on the second arrangement jig body 42. By inserting the positioning pin 422 into the pin hole 412, the first arrangement jig body 41 and the second arrangement jig body 42 can be easily combined.

[0037] 7, the arrangement jig main body 40 is formed with a third cavity 63 penetrating the arrangement jig main body 40 in the front-rear direction X. The third cavity 63 is formed so as to intersect with the portion where the annular portion 12 is arranged when the annular portion 12 is arranged in the first cavity 61. In this embodiment, the cross-sectional shape of the third cavity 63 is formed so as to substantially match the cross-sectional shape of the through-hole 12b of the annular portion 12, but is not limited to this. A ring-side electrode rod 70 (described below) is inserted into the third cavity 63.

[0038] (Example of component placement process: pin jig 50) As described above, the pin jig 50 is used to position the anti-rotation pin 2 with respect to the annular portion 12 in the welding process. The pin jig 50 is made of an insulating material, such as ceramic. The pin jig 50 has a cylindrical hole 52. As shown in FIG. 7 , the cylindrical hole 52 is a through-hole that penetrates in the front-rear direction X when the pin jig 50 is fitted into the second hollow portion 62. The anti-rotation pin 2 is placed in the cylindrical hole 52 with an end of the anti-rotation pin 2 protruding into the fourth hollow portion 64. In this state, when the pin jig 50 is fitted into the second hollow portion 62, the lower side Z2 of the protrusion 2b of the anti-rotation pin 2 abuts against the outer peripheral surface of the annular portion 12.

[0039] Although not shown, a member for positioning the anti-rotation pin 2 in the front-rear direction X relative to the pin jig 50 may be provided. For example, a restricting member may be provided that restricts the cylindrical hole 52 to a hole of a predetermined length. Furthermore, a restricting member may be provided in the fourth hollow portion 64 that restricts movement of the anti-rotation pin 2 toward the front side X1. It is preferable that these restricting members position the protrusion 2b of the anti-rotation pin 2 so that it is located more inward than both axial ends of the annular portion 12.

[0040] (A specific example of the parts placement process) The positioning of the anti-rotation pin 2 relative to the eye joint 1B is performed using the arrangement jig as described above. Specifically, the component arrangement process includes the following first to third steps. As shown in FIG. 7, in the first step, the annular portion 12 and the pipe connection portion 15 are arranged in the first cavity 61. For example, the annular portion 12 and the pipe connection portion 15 are fitted into the first arrangement jig body 41. Then, the second arrangement jig body 42 is abutted against the first arrangement jig body 41 into which the annular portion 12 and the pipe connection portion 15 are fitted, while being positioned by the pin hole 412 and the positioning pin 422.

[0041] In the second step, the pin jig 50, with the anti-rotation pin 2 fitted into the cylindrical hole 52, is fitted into the second hollow portion 62. Then, the pin jig 50 is placed in the second hollow portion 62. At this time, the lower side Z2 of the protrusion 2b of the anti-rotation pin 2 protruding from the pin jig 50 to the front side X1 abuts against the upper side Z1 of the annular portion 12 of the eye joint 1B.

[0042] In the third step, the annular portion-side electrode rod 70, which is an electrode for resistance welding, is inserted into the third hollow portion 63 from the front side X1. As a result, the annular portion-side electrode rod 70 is inserted into the through hole 12b of the annular portion 12 and electrically connected to the annular portion 12. Then, the pin-side electrode rod 71 is brought into contact with the annular portion 12 from the side opposite to the contact point of the anti-rotation pin 2 with the annular portion 12. Note that this third step may be performed in the welding step described below.

[0043] (Manufacturing method of eye joint 100B with anti-rotation pin: welding process) Next, a welding process is performed in which the protrusion 2b and the outer circumferential surface of the annular portion 12 are resistance-welded together. In the resistance welding, the pin-side electrode rod 71 applies pressure to the lower side Z2 of the anti-rotation pin 2 while a current is passed from a battery (not shown) to perform the resistance welding. When the resistance welding is performed, the portion of the anti-rotation pin 2 that is in contact with the annular portion 12 is melted and joined to the outer circumferential surface of the annular portion 12.

[0044] In this way, a welding process is performed in which anti-rotation pin 2 is resistance-welded to eye joint 1B. As shown in FIG. 3, anti-rotation pin 2 has a tapered protrusion 2b at the end on the side to be resistance-welded. This increases the electrical resistance at the point of contact between anti-rotation pin 2 and annular portion 12, allowing the heat generated by resistance welding to be more concentrated on protrusion 2b and melt it. In this way, in this embodiment, no welding material is used, and protrusion 2b of anti-rotation pin 2 is melted and joined to eye joint 1B, but the present invention is not limited to this.

[0045] Furthermore, even if the protrusion 2b melts, the pin jig 50 prevents the anti-rotation pin 2 from moving downward Z2, thereby reducing the risk of the anti-rotation pin 2 being joined too close to the annular portion 12.

[0046] The above has described a method for manufacturing the anti-rotation pin eye joint 100B according to one embodiment of the present invention. The above description has disclosed the following technical features regarding the method for manufacturing the anti-rotation pin eye joint 100B.

[0047] The manufacturing method for eye joint 100B with anti-rotation pin of this embodiment is a manufacturing method in which eye joint 1B, which has a cylindrical portion such as socket 11 or pipe connection portion 15 at its end and also has an annular portion 12, is joined to anti-rotation pin 2. The manufacturing method for eye joint 100B with anti-rotation pin includes a protrusion forming process in which protrusion 2b is formed on the side surface of the end of anti-rotation pin 2, a component arrangement process in which eye joint 1B and anti-rotation pin 2 are arranged so that protrusion 2b contacts the outer peripheral surface of annular portion 12, and a welding process in which protrusion 2b is resistance-welded to the outer peripheral surface of annular portion 12.

[0048] According to the above configuration, resistance welding is performed with the protrusion 2b formed on the side end of the anti-rotation pin 2 in contact with the outer circumferential surface of the annular portion 12 of the eye joint 1B. During the welding process, the main body 2a of the anti-rotation pin 2 is separated from the annular portion 12 by the protrusion 2b. Therefore, even if the protrusion 2b in contact with the annular portion 12 melts during resistance welding, the anti-rotation pin 2 and the annular portion 12 are prevented from coming too close to each other or from sinking into the main body 2a of the anti-rotation pin 2. As a result, interference between the anti-rotation pin 2 and the molten material and bolts inserted into the annular portion 12 is reduced, maintaining conventional functionality. Furthermore, conventional processes such as forming a recess on the side of the annular portion 12 of the eye joint 1B, press-fitting the anti-rotation pin into the recess and brazing it, and bending the anti-rotation pin can be omitted, thereby reducing manufacturing costs.

[0049] In addition, in the manufacturing method of the anti-rotation pin eye joint 100B of this embodiment, as shown in Figure 5A, in the protrusion forming process, a second protrusion 2bB2 having a flat portion 2bB3 is formed on the side of the anti-rotation pin 2 opposite the protrusion 2bB1, together with the tapered protrusion 2bB1.

[0050] According to the above configuration, the electrode terminal can be stably pressed against the flat portion 2bB3 in the welding process. Furthermore, by welding the tapered protrusion 2bB1 in contact with the annular portion 12, the resistance value at this contact point can be increased, enabling efficient resistance welding.

[0051] In addition, in the manufacturing method of the anti-rotation pin eye joint 100B of this embodiment, as shown in Figure 5A, the shape formed by the protrusion 2bB1 and the second protrusion 2bB2 is approximately pentagonal when viewed from the axial direction of the anti-rotation pin 2.

[0052] According to the above configuration, the electrode terminal can be stably pressed against the flat portion 2bB3 in the welding process. Furthermore, by welding the tapered protrusion 2bB1 in contact with the annular portion 12, the resistance value at this contact point can be increased, enabling efficient resistance welding.

[0053] In addition, in the manufacturing method of the anti-rotation pin eye joint 100A of this embodiment, as shown in Figure 1, in the protrusion forming process, a ring-shaped protrusion 2b (protrusion 2bA in the example shown in Figure 4A) is formed when viewed from the axial direction of the anti-rotation pin 2.

[0054] According to the above configuration, the anti-rotation pin 2 can be brought into contact with the annular portion 12 at any position on the ring while the main body portion 2a is separated, making it easy to position the anti-rotation pin 2 relative to the eye joint 1A.

[0055] In addition, in the manufacturing method of the anti-rotation pin eye joint 100A of this embodiment, the protrusion 2b has a mountain shape when viewed from the side of the anti-rotation pin 2.

[0056] According to the above configuration, the protrusion 2b can be brought into contact with the annular portion 12 at a point, so that the resistance value at this contact point can be increased, and resistance welding can be carried out efficiently.

[0057] In addition, in the manufacturing method of the eye joint 100A with anti-rotation pin of this embodiment, the thickness H1 of the protrusion portion 2b in the axial direction of the anti-rotation pin 2 is smaller than the thickness H2 of the annular portion 12, and in the component placement process, the protrusion portion 2b is positioned inside both axial ends of the annular portion 12.

[0058] According to the above configuration, the protrusion portion 2b is configured so as not to protrude in the thickness direction of the annular portion 12, thereby reducing the possibility of the protrusion portion 2b interfering with the bolt or the object to be attached when installing the anti-rotation pin-equipped eye joint 100A.

[0059] Although examples of the present invention have been described above, they are merely illustrative examples and do not limit the present invention, and specific configurations and the like can be appropriately modified in design. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferable actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments of the present invention. [Example]

[0060] (Pin strength of anti-rotation pin 2) Next, the pin strength of the anti-rotation pin in the anti-rotation pin eye joint will be specifically described using a comparative example and an example of the anti-rotation pin eye joint according to this embodiment.

[0061] Comparative Examples 1 to 3 are conventional eye joint with anti-rotation pin 200 (see FIG. 8) manufactured through a process of forming a recess on the side surface of annular portion 212 of eye joint 201, a process of press-fitting and brazing anti-rotation pin 202 into the recess, and a process of bending anti-rotation pin 202. Also, Examples 1 to 3 are eye joint with anti-rotation pin 100B provided with ring-shaped protrusion 2b as shown in FIG. 3 (protrusion 2b is not shown in FIG. 8).

[0062] In both Comparative Examples 1 to 3 and Examples 1 to 3, SWCH12A, which has a carbon content of 0.10% by weight or more and 0.15% by weight or less according to the JIS standard, was used as the material for the eye joints 1B and 201. In both Comparative Examples 1 to 3 and Examples 1 to 3, SWCH45K, which has a carbon content of 0.42% by weight or more and 0.48% by weight or less according to the JIS standard, was used as the material for the anti-rotation pins 2 and 202.

[0063] Furthermore, torque test jig 3 shown in FIG. 8 was used to measure the pin strength of anti-rotation pins 2 and 202. Specifically, torque test jig 3 has a mounting stand 33 on which anti-rotation pin eye joints 100B and 200 are placed, a fitting portion 31 that fits into the through-hole of annular portion 12 and 212 of anti-rotation pin eye joints 100B and 200 on mounting stand 33, and a stopper portion 32 that stops rotation of anti-rotation pin eye joints 100B and 200. Anti-rotation pin eye joints 100B and 200 fitted into fitting portion 31 are made rotatable. When anti-rotation pin eye joints 100B and 200 are rotated, stopper portion 32 comes into contact with anti-rotation pins 2 and 202 at a predetermined position, preventing rotation. In this state, torque was applied in the direction of restraint by restraining portion 32 of anti-rotation pin eye joints 100B and 200 of the comparative example and the working example, and the strength was measured when a change occurred in the state of the pin.

[0064] [Table 1]

[0065] As a result, as shown in Table 1, the pin strengths of the anti-rotation pins 202 of Comparative Examples 1 to 3 were 16, 13, and 13 N m, respectively. Specifically, at these strengths, the anti-rotation pins 202 were deformed. On the other hand, the pin strengths of the anti-rotation pins 2 of Examples 1 to 3 were 30, 28, and 25 N m, respectively. Specifically, at these strengths, the welded portion of the anti-rotation pin 2 broke. Thus, it was found that the pin strength of the anti-rotation pins 2 of the Examples was significantly improved over the anti-rotation pin 202 of the Comparative Example, which was manufactured by the conventional manufacturing method.

[0066] In this way, it was found that even if the anti-rotation pin 2 was simply joined to the eye joint 1B by resistance welding, it was possible to achieve pin strength greater than that of conventional pins and maintain conventional functionality. [Explanation of symbols]

[0067] 1A·1B: Eye joint 2·2A·2B: Anti-rotation pin 2a: Main body 2b・2bA・2bB1:Protrusion 2bB2: 2nd protrusion 2bB3: Flat part 11: Socket (cylindrical part) 12: Annular part 13: Neck 15: Pipe connection 16: Pipe 100A·100B: Eye joint with anti-rotation pin

Claims

1. A method for manufacturing an eye joint with a rotation prevention pin, which is formed by combining an eye joint having a cylindrical portion or a pipe connection portion at an end and a circular portion, with a rotation prevention pin, a protrusion forming step of forming a protrusion on a side surface of the end of the anti-rotation pin; a component placement process of placing the eye joint and the anti-rotation pin so that the protrusion contacts the outer peripheral surface of the annular portion; a welding step of resistance welding the protrusion and the outer circumferential surface; Equipped with Manufacturing method for eye joint with anti-rotation pin.

2. 2. A method for manufacturing the locking pin eye joint according to claim 1, comprising the steps of: In the protrusion forming step, a second protrusion having a flat portion is formed on the side surface opposite to the protrusion, together with the tapered protrusion. Manufacturing method for eye joint with anti-rotation pin.

3. 3. A method for manufacturing the locking pin eye joint according to claim 2, comprising the steps of: a shape formed by the protruding portion and the second protruding portion is substantially pentagonal when viewed from the axial direction of the anti-rotation pin; Manufacturing method for eye joint with anti-rotation pin.

4. 2. A method for manufacturing the locking pin eye joint according to claim 1, comprising the steps of: In the protrusion forming step, the protrusion is formed to have a ring shape when viewed in the axial direction of the anti-rotation pin. Manufacturing method for eye joint with anti-rotation pin.

5. 5. A method for manufacturing the locking pin eye joint according to claim 4, comprising the steps of: The protrusion has a mountain shape when viewed from the side of the anti-rotation pin. Manufacturing method for eye joint with anti-rotation pin.

6. A method for manufacturing an eye joint with a locking pin according to any one of claims 1 to 5, comprising: a thickness of the protrusion in the axial direction of the anti-rotation pin is smaller than a thickness of the annular portion, In the component placement step, the protrusion is placed inside both ends of the annular portion in the axial direction. Manufacturing method for eye joint with anti-rotation pin.

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