Method of manufacturing an eccentric contact holder

Abstract

The application discloses a manufacturing method of an eccentric contact seat, which has a seat head and a shaft part extending from the seat head, the shaft part comprises a first section close to the seat head and not eccentric, a second section away from the seat head and eccentric, and a transition part between the first and second sections, wherein the first and second sections have the same diameter, the method comprises the following steps: providing a round bar blank with a diameter corresponding to the diameter of the first section of the shaft part of the eccentric contact seat; forming the round bar blank into a first intermediate bar with a free-form ball table shape at one end through a first die pressing process; forming the first intermediate bar into a second intermediate bar with a finished seat head shape at one end through a second die pressing process; and extruding the shaft part of the second intermediate bar through a third die pressing process, so as to form the finished eccentric contact seat with the non-eccentric section, the transition part and the eccentric section. The method of the application can manufacture the reliable eccentric contact seat through three extrusion processes, and can remarkably reduce the waste of metal materials and the product cost.

Description

Technical Field

[0001] This invention relates to a method or process for manufacturing an eccentric contact seat. Background Technology

[0002] Eccentric contacts are widely used as components of electrical connectors. Because these eccentric contacts have eccentric and non-eccentric sections on their shaft, existing technology involves first providing a blank with a significantly increased diameter, then machining this blank using cutting and other methods to form the contact head, non-eccentric shaft section, and eccentric shaft section, thus obtaining the desired product. This manufacturing method obviously wastes a considerable amount of metal material, thereby increasing the product cost. Summary of the Invention

[0003] The purpose of this invention is to provide a method for manufacturing an eccentric contact seat, which can significantly reduce the waste of metal materials and reduce product costs.

[0004] The eccentric contactor to be manufactured by the present invention has a cylindrical head and a shaft extending from one end of the cylindrical head to one side. The shaft includes a cylindrical first section close to and coaxial with the head, a cylindrical second section away from the head and whose axis is offset relative to the head axis, and a transition section between the first and second sections. The first and second sections have the same diameter, which is smaller than the diameter of the head.

[0005] The manufacturing method of the present invention includes:

[0006] Provide a (solid) round bar blank, the diameter of which corresponds to the diameter of the first section of the shaft of the eccentric contact (the two are substantially equal);

[0007] A first die is provided, the first die having a cylindrical inner cavity whose diameter corresponds to the diameter of the first section of the shaft portion of the eccentric contact seat;

[0008] A first punch is provided, the first punch having a truncated conical cavity, the bottom diameter of the cavity being smaller than (slightly smaller than) the diameter of the round bar blank, and the volume of the cavity being smaller than the volume of the cylindrical seat head of the eccentric contact seat.

[0009] A first circular pad is provided, the diameter of which corresponds to the diameter of the cylindrical inner cavity of the first die;

[0010] The first round pad is placed into the cylindrical cavity of the first die, and the round bar blank is placed into the cylindrical cavity of the first die. One end of the round bar blank overlaps with the end face of the first round pad, and the other end of the round bar blank extends out of the cylindrical cavity of the first die, so that the volume of the part of the round bar blank outside the cylindrical cavity of the first die corresponds to the volume of the eccentric contact cylindrical seat head.

[0011] After aligning the first punch with the first die, press down the first punch to extrude the round bar blank, so that the round bar blank fills the cavity of the first punch and the free forming part of the round bar blank between the first punch and the first die is in the shape of a frustum. The maximum outer diameter of the frustum shape is less than or equal to the diameter of the eccentric contact seat head, thereby obtaining the first intermediate bar.

[0012] A second die is provided, the second die having a coaxial cylindrical first inner cavity and a cylindrical second inner cavity arranged sequentially along the axial direction, the diameter of the first inner cavity corresponding to the diameter of the first section of the shaft of the eccentric contact, the diameter of the second inner cavity corresponding to the diameter of the eccentric contact head, and a step is formed at the boundary between the first inner cavity and the second inner cavity.

[0013] A second punch is provided, the second punch having a cylindrical shape, the diameter of which corresponds to the diameter of the second inner cavity of the second die;

[0014] A second circular pad is provided, the diameter of which corresponds to the diameter of the first inner cavity of the second die;

[0015] The second round pad is placed into the first inner cavity of the second die, and the first intermediate bar is placed into the second die, such that one end of the first intermediate bar with the shape of a ball table is located in the second inner cavity and the end face of the ball table abuts against the step surface at the boundary between the first inner cavity and the second inner cavity, and the other end of the first intermediate bar is located in the first inner cavity and abuts against the second round pad.

[0016] After aligning the second punch with the second die, press down the second punch to extrude the first intermediate bar stock, causing the end of the first intermediate bar stock with the shape of a ball table to deform into a seat head of an eccentric contact seat, thereby obtaining the second intermediate bar stock. The second intermediate bar stock has a cylindrical seat head and a shaft portion coaxial with the seat head that extends from one end of the seat head to one side.

[0017] A third die is provided, the third die having a first part that provides rigid support to the shaft portion of the second intermediate bar stock and a second part that provides elastic support to the shaft portion of the second intermediate bar stock;

[0018] A third punch is provided, which has a rigidly pressing first part and an elastically pressing second part, wherein the rigidly pressing first part corresponds to the elastically supporting second part of the third die, and the elastically pressing second part corresponds to the rigidly supporting first part of the third die.

[0019] The shaft of the second intermediate bar is placed horizontally in the first and second parts of the third die, such that the seat of the second intermediate bar is located on one side of the first part and abuts against the side of the first part.

[0020] After aligning the third punch and the third die, the third punch is pressed down to extrude the axial portion of the second intermediate bar. The first part of the third die and the second part of the third punch together fix the axial portion of the second intermediate bar near the seat head. The second part of the third die and the first part of the third punch together cause the axial portion of the second intermediate bar away from the seat head to shift in the pressing direction of the third punch, thereby forming an eccentric contact seat product.

[0021] According to a preferred embodiment of the present invention, the first part of the third die cavity is a first support block for supporting the shaft portion of the second intermediate bar stock. The upper end of the first support block has a semi-circular or nearly semi-circular groove. The diameter of the groove is equal to or slightly larger than the diameter of the first section of the shaft portion of the eccentric contact seat, and the length of the groove is equal to the length of the first section of the shaft portion of the eccentric contact seat. The second part of the third die cavity includes a second support block for supporting the shaft portion of the second intermediate bar stock and a third support block connected to the second support block via a spring and a threaded connector. The third support block has a stepped hole, and the end of the threaded connector with the larger radial dimension can... The third support block moves axially in the stepped hole with a larger radial dimension and is stopped by the stepped surface of the stepped hole. The other end of the threaded connector is fixedly connected to the second support block by threads. In the assembled state, the spring connected between the second support block and the third support block is under compression. The upper end of the second support block has a semi-circular or nearly semi-circular groove. The diameter of the groove is equal to or slightly larger than the diameter of the second section of the shaft of the eccentric contact. The length of the groove is preferably equal to the length of the second section of the shaft of the eccentric contact. The central axis of the groove of the second support block coincides with the central axis of the groove of the first support block.

[0022] According to a preferred embodiment of the present invention, the first part of the third punch is a first pressure block, the lower end of which is formed with a semi-circular or nearly semi-circular groove. The diameter of the groove is equal to or slightly larger than the diameter of the second section of the eccentric contact shaft, and the length of the groove is preferably equal to the length of the second section of the eccentric contact shaft. The second part of the third punch includes a second pressure block corresponding to the first support block of the third die and a third pressure block connected to the second pressure block via a spring and a threaded connector. The third pressure block is formed with a stepped hole. The end of the threaded connector with a larger radial dimension can move axially within the stepped hole of the third pressure block and is stopped by the stepped surface of the stepped hole. The other end of the connector is fixedly connected to the second pressure block by a thread. In the assembled state, the spring connecting the second pressure block and the third pressure block is under pressure. The lower end of the second pressure block has a semi-circular or nearly semi-circular groove. The diameter of the groove is equal to or slightly larger than the diameter of the first section of the shaft of the eccentric contact seat. The length of the groove is equal to the length of the first section of the shaft of the eccentric contact seat. The central axis of the groove of the second pressure block coincides with the central axis of the groove of the first pressure block. Before the third punch is pressed down, the shaft of the second intermediate bar is horizontally placed in the groove of the first support block and the second support block, so that the seat head of the second intermediate bar is located on one side of the first support block and abuts against the side of the first support block.

[0023] According to a preferred embodiment of the present invention, the truncated conical cavity of the first punch has a first taper and a second taper sequentially from the bottom to the opening, wherein the first taper is smaller than the second taper. Preferably, the first taper is 1.5° and the second taper is 3.5°.

[0024] Preferably, the dimension obtained by subtracting the height of the first tapered cavity from the height of the portion of the round bar billet not placed in the first die is equal to twice the diameter of the round bar billet.

[0025] Preferably, the volume of the truncated conical cavity of the first punch is 65%-80% of the volume of the eccentric contact seat head.

[0026] Preferably, the spring constant of the spring in the second part of the third die cavity is less than the spring constant of the spring in the second part of the third punch.

[0027] Preferably, the spring in the second part of the third die cavity is a helical spring, and the spring in the second part of the third punch is a disc spring.

[0028] In addition, threaded fasteners can be bolts or screws.

[0029] The manufacturing method of this invention is reliable and practical. It produces a reliable eccentric contact seat through three extrusion processes, which significantly reduces the waste of metal materials and lowers product costs. Attached Figure Description

[0030] Figure 1 A schematic diagram of the structure of the eccentric contactor manufactured according to the present invention is shown;

[0031] Figure 2 A schematic diagram of the first extrusion step according to the manufacturing method of the present invention is shown;

[0032] Figure 3 A schematic diagram of the second extrusion step according to the manufacturing method of the present invention is shown;

[0033] Figure 4 A schematic diagram is shown of the third extrusion step according to the manufacturing method of the present invention before extrusion; and

[0034] Figure 5 A schematic diagram is shown after the third extrusion step of the manufacturing method according to the present invention has been performed. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings. Those skilled in the art should understand that the embodiments described below are merely illustrative examples of the invention and are not intended to limit it in any way.

[0036] like Figure 1 As shown, the eccentric contact 10 to be manufactured by the present invention has a cylindrical head 11 and a shaft portion extending from one end of the cylindrical head to one side. The shaft portion includes a cylindrical first section 12 that is close to and coaxial with the head, a cylindrical second section 13 that is far from the head and whose axis is offset by a distance d relative to the head axis, and a transition portion 14 located between the first section 12 and the second section 13. The first section 12 and the second section 13 have the same diameter, which is smaller than the diameter of the head 11.

[0037] In one specific embodiment of the present invention, the eccentric contact 10 is made of copper alloy material.

[0038] Figure 2 A schematic diagram of the first extrusion / molding process of the eccentric contact manufacturing method according to the present invention is shown.

[0039] First, a (solid) round bar blank 102 is formed by forging copper alloy material. The diameter of the round bar blank 102 corresponds to the diameter of the first section of the shaft of the eccentric contact (the two are basically equal). Based on the principle of equal volume in the molding process, that is, the volume of the round bar blank 102 corresponds to the material volume of the finished eccentric contact, the length of the round bar blank 102 can be obtained.

[0040] like Figure 2 As shown, the mold used in this process includes a first concave mold 105, a first convex mold 101, and a first round pad 106.

[0041] The first die 105 has a cylindrical inner cavity, the diameter of which corresponds to the diameter of the first section of the shaft of the eccentric contact seat (i.e., the diameter of the round bar blank 102). The first die 105 can be fixed and prestressed by a first prestressing ring 103, which is firmly fixed to the working platform of the molding press. It will be understood by those skilled in the art that the use of the first prestressing ring 103 to fix the first die 105 is merely exemplary, and any other suitable fixing / connection method can be selected according to the actual application scenario.

[0042] A portion of the round bar blank 102 is placed into the first cavity 105, wherein the volume of the unplaced portion (the volume of the portion exposed outside the first cavity 105) is equal to the volume of the seat head of the finished eccentric contact seat. The bottom of the round bar blank 102 is supported by the first circular pad 106.

[0043] The first punch 101 can be fixed on the movable crossbeam of the molding press (not shown in the figure). The lower end of the first punch 101 is machined with a cavity with double tapers. The volume of the cavity is smaller than the volume of the finished eccentric contact head (preferably 65-80% of the volume of the finished eccentric contact head). The bottom of the cavity is slightly smaller than the diameter of the round bar blank 102, so as to control and position the round bar blank 102 during the molding process. Here, the first taper B can be 1.5°. The height of the part of the round bar blank 102 not placed in the first die 105 minus the height of the corresponding part of the first taper B is equal to (approximately equal to) twice the diameter of the round bar blank 102. This is mainly to control the head deformation and prevent instability during the molding deformation process. The second taper A can be 3.5°. When the first punch 101 moves downward, the upper part of the round bar blank 102 is positioned and controlled by the bottom of the cavity of the first punch 101, and at the same time, the round bar blank 102 begins to deform and fill the cavity. The free-forming portion of the round bar billet 102 between the first punch 101 and the first die 105 is shaped like a ball table, with its maximum outer diameter D being smaller than the diameter of the finished eccentric contact head, thus obtaining the first intermediate bar 104. After the first extrusion process is completed, the movable crossbeam drives the first punch 101 upward, and the equipment ejection system pushes the first round pad 106 upward, thereby ejecting the first intermediate bar 104 from the first die 105.

[0044] Figure 3 A schematic diagram of the second extrusion step according to the eccentric contact manufacturing method of the present invention is shown.

[0045] like Figure 3As shown, the mold used in the second extrusion process includes: a second die 203, a second punch 201, and a second round pad 205. The second die 203 has two cylindrical inner cavities arranged coaxially along the axial direction: a first cylindrical cavity (the smaller diameter cavity located at the bottom in the figure) and a second cylindrical cavity (the larger diameter cavity located at the top in the figure). The diameter of the first cavity corresponds to the diameter of the first section of the shaft portion of the finished eccentric contact seat, and the diameter of the second cavity corresponds to the diameter of the head of the finished eccentric contact seat. A step is formed at the boundary between the first and second inner cavities. The second punch 201 has a cylindrical shape, and its diameter corresponds to the diameter of the second inner cavity of the second die. The diameter of the second round pad 205 corresponds to the diameter of the first inner cavity of the second die 203.

[0046] The second die 203 can be pre-tightened and fixed by the second prestressing ring 202, which is firmly fixed to the working platform of the molding machine. The first intermediate bar 104 obtained in the first process is placed into the second die 203. The shaft portion of the first intermediate bar 104 with a smaller diameter is located in the first inner cavity of the second die 203, and its end is supported by the second round pad 205. The head portion of the first intermediate bar 104 with a larger diameter is located in the second inner cavity of the second die 203, and the interface between the shaft portion and the head portion just abuts against the stepped surface of the inner cavity of the second die.

[0047] The second punch 201 can be fixed on the movable crossbeam of the molding press (not shown in the figure). The downward movement of the movable crossbeam drives the second punch 201 to move downward. Under the action of the second punch 201, the head of the first intermediate bar stock 104 is deformed (forged), thus obtaining the second intermediate bar stock 204. The second intermediate bar stock 204 has a cylindrical seat head (which is completely consistent with the seat head of the finished eccentric contact seat) and a shaft portion coaxial with the seat head extending from one end face of the seat head to one side. After the second extrusion process is completed, the second punch 201 moves upward, and the equipment ejection system pushes the second round pad 205 upward, thereby ejecting the second intermediate bar stock 204 from the second die 203.

[0048] Figure 4 A schematic diagram is shown before the extrusion process of the third extrusion step according to the eccentric contact manufacturing method of the present invention. Figure 5 A schematic diagram is shown after the third extrusion step of the manufacturing method according to the present invention has been performed.

[0049] See Figure 4 and Figure 5The purpose of the third extrusion process is to extrude the coaxial portion of the second intermediate bar 204 into three segments: a first segment close to and coaxial with the seat head, a second end (tail) away from and not coaxial with the seat head, and a transition segment between the first and second segments. During the extrusion process, the first segment only needs to remain fixed, while the second segment (tail) is offset relative to the first segment. In this invention, the first segment is fixed using a combination of rigid support and elastic pressure, and the second segment is offset using a combination of elastic support and rigid pressure.

[0050] Specifically, such as Figure 4 As shown, in this preferred embodiment, the third die used in the third extrusion process comprises two parts. The first part is a first support block 304 (providing rigid support for the shaft portion of the second intermediate bar 204) that can be fixed on the working platform of the molding press. The upper end of the first support block 304 has a semi-circular or nearly semi-circular groove. The diameter of the groove is equal to or slightly larger than the diameter of the first section (non-eccentric section) of the shaft portion of the eccentric contact seat, and the length of the groove is equal to the length of the first section of the shaft portion of the eccentric contact seat. The second part is an assembly (providing elastic support for the shaft portion of the second intermediate bar 204). This assembly includes a second support block 308 and a third support block 305 that can be fixed on the working platform of the molding press. The upper end of the second support block 308 also has a semi-circular or nearly semi-circular groove. The diameter of the groove is equal to or slightly larger than the diameter of the second section (eccentric section) of the shaft portion of the eccentric contact seat, and the length of the groove is equal to the length of the first section of the shaft portion of the eccentric contact seat. The length of the second section of the shaft portion is equal to that of the eccentric contact seat. The center axis of the groove of the second support block 308 coincides with the center axis of the groove of the first support block 304. The second support block 308 and the third support block 305 are connected to each other by a first bolt 306 (or a screw or other threaded connector) and a spring 307 (which can be a helical spring, and multiple helical springs can be provided, with the first bolt 306 passing through the core of the spring 307). The third support block 305 has a stepped hole. The end of the first bolt 306 with a larger radial dimension can move axially in the stepped hole of the third support block 305 and be stopped by the stepped surface of the stepped hole. The other end of the first bolt 306 is fixedly connected to the second support block 308 by a thread. In the assembled state, the spring 307 connected between the second support block 308 and the third support block 305 is under pressure. When the second support block 308 is pressed, it can push the spring 307 downward, and at the same time, the first bolt 306 also moves downward along the hole in the third support block 305 as the second support block 308 moves downward. When the downward pressure on the second support block 308 is removed, the spring 307 can push the second support block 308 upward, and the first bolt 306 controls the reset position of the second support block 308.

[0051] The third punch used in the third extrusion process also comprises two parts. The first part is a first pressure block 309 (corresponding to the assembly of the second part of the third die, providing rigid pressure to the tail end of the shaft portion of the second intermediate bar stock 204) that can be fixed on the movable crossbeam of the molding press. The lower end of the first pressure block 309 has a semi-circular or nearly semi-circular groove, the diameter of which is equal to or slightly larger than the diameter of the second section (eccentric section) of the shaft portion of the eccentric contact seat, and the length of which is preferably equal to the length of the second section of the shaft portion of the eccentric contact seat. The second part is an assembly (corresponding to the rigid support block of the first part of the third die, providing elastic pressure to the head end of the shaft portion of the second intermediate bar stock 204 for fixation). This assembly includes a second pressure block 303 for pressing the shaft portion of the second intermediate bar stock 204 and a third pressure block 301 that can be fixed on the movable crossbeam of the molding press. The lower end of the second pressure block 303 also has a semi-circular or nearly semi-circular groove, the diameter of which is equal to or slightly larger than the diameter of the shaft portion of the eccentric contact seat. The diameter of the groove is slightly larger than that of the first section of the shaft of the eccentric contact seat. The length of the groove is equal to the length of the first section of the shaft of the eccentric contact seat. The central axis of the groove of the second pressure block 303 coincides with the central axis of the groove of the first pressure block 309. The second pressure block 303 and the third pressure block 301 are connected to each other by a second bolt 310 (or a screw or other threaded connector) and a disc spring 302 (or a helical spring with a large elastic coefficient; multiple disc springs can be provided, and the second bolt 310 can pass through the core of the disc spring 302). The third pressure block 301 has a stepped hole. The end of the second bolt 310 with a larger radial dimension can move axially in the stepped hole of the third pressure block 301 and be stopped by the stepped surface of the stepped hole. The other end of the second bolt 310 is fixedly connected to the second pressure block 303 by a thread. In the assembled state, the disc spring 302 connected between the second pressure block 303 and the third pressure block 301 is under pressure. When the third pressure block 301 is pressed, it can press the disc spring 302 downward, thereby pressing the shaft portion of the second intermediate bar 204 near the seat head (which cooperates with the first support block 304 to fix the shaft portion of the second intermediate bar 204 near the seat head). At the same time, the second bolt 310 can move within the hole of the third pressure block 301. When the downward pressure applied to the third pressure block 301 disappears, the disc spring 302 can push the third pressure block 301 upward, and the second bolt 310 controls the reset position of the third pressure block 301.

[0052] The main reason for using a disc spring 302 near the head of the second intermediate bar 204 and a coil spring near the tail of the second intermediate bar 204 is that, under the same compression stroke, the force generated by the disc spring 302 is much greater than the force generated by the coil spring 307. This ensures that the second intermediate bar 204 will not become unstable during the third molding process.

[0053] See below. Figure 4 and Figure 5 This describes the process of the third molding step.

[0054] First, the shaft of the second intermediate bar 204 is placed horizontally in the groove of the first support block 304 and the second support block 308, and the seat of the second intermediate bar 204 is placed on the left side of the first support block 304 and abuts against the first support block 304.

[0055] Next, the moving crossbeam of the molding press descends, and the first pressure block 309 and the second pressure block 303 press against the shaft portion of the second intermediate bar stock 204. The first pressure block 309 corresponds to (fits) the second support block 308, and the second pressure block 303 corresponds to (fits) the first support block 304. As the moving crossbeam continues to descend, the second pressure block 303 and the first support block 304 firmly fix the corresponding shaft portion of the second intermediate bar stock 204 (near the head section); while the first pressure block 309 and the second support block 308 together drive the corresponding shaft portion of the second intermediate bar stock 204 (away from the head section, i.e., the tail) downwards, causing the tail portion of the shaft portion of the second intermediate bar stock 204 to shift (translate), thus forming an eccentric contact seat for the finished product. Figure 5 As shown.

[0056] After the forming is completed, the movable crossbeam moves upward, the helical spring 307 pushes the second support block 308 to move upward and reset, and the disc spring 302 pushes the second pressure block 303 to move upward and reset.

[0057] As described above, the present invention produces a reliable eccentric contact seat through the first to third extrusion processes, which can significantly reduce the waste of metal materials and reduce costs.

Claims

1. A method for manufacturing an eccentric contactor, the eccentric contactor having a cylindrical head and a shaft extending from one end face of the cylindrical head to one side, the shaft including a cylindrical first segment adjacent to and coaxial with the head, a cylindrical second segment away from the head and whose axis is offset relative to the head axis, and a transition portion located between the first segment and the second segment, the first segment and the second segment having the same diameter, the diameter being smaller than the diameter of the head, the method comprising: A round bar blank is provided, the diameter of which corresponds to the diameter of the first section of the shaft portion of the eccentric contact seat; A first die is provided, the first die having a cylindrical inner cavity whose diameter corresponds to the diameter of the first section of the shaft portion of the eccentric contact seat; A first punch is provided, which forms a truncated conical cavity. The bottom diameter of the cavity is slightly smaller than the diameter of the round bar blank, and the volume of the cavity is smaller than the volume of the cylindrical seat head of the eccentric contact. A first circular pad is provided, the diameter of which corresponds to the diameter of the cylindrical inner cavity of the first die; The first round pad is placed into the cylindrical cavity of the first die, and the round bar blank is placed into the cylindrical cavity of the first die. One end of the round bar blank overlaps with the end face of the first round pad, and the other end of the round bar blank extends out of the cylindrical cavity of the first die, so that the volume of the part of the round bar blank outside the cylindrical cavity of the first die corresponds to the volume of the eccentric contact cylindrical seat head. After aligning the first punch with the first die, press down the first punch to extrude the round bar blank, so that the round bar blank fills the cavity of the first punch and the free forming part of the round bar blank between the first punch and the first die is in the shape of a frustum. The maximum outer diameter of the frustum shape is less than or equal to the diameter of the eccentric contact seat head, thereby obtaining the first intermediate bar. A second die is provided, the second die having a coaxial cylindrical first inner cavity and a cylindrical second inner cavity arranged sequentially along the axial direction, the diameter of the first inner cavity corresponding to the diameter of the first section of the shaft of the eccentric contact, the diameter of the second inner cavity corresponding to the diameter of the eccentric contact head, and a step is formed at the boundary between the first inner cavity and the second inner cavity. A second punch is provided, the second punch having a cylindrical shape, the diameter of which corresponds to the diameter of the second inner cavity of the second die; A second circular pad is provided, the diameter of which corresponds to the diameter of the first inner cavity of the second die; The second round pad is placed into the first inner cavity of the second die, and the first intermediate bar is placed into the second die, such that one end of the first intermediate bar with the shape of a ball table is located in the second inner cavity and the end face of the ball table abuts against the step surface at the boundary between the first inner cavity and the second inner cavity, and the other end of the first intermediate bar is located in the first inner cavity and abuts against the second round pad. After aligning the second punch with the second die, press down the second punch to extrude the first intermediate bar stock, causing the end of the first intermediate bar stock with the shape of a ball table to deform into a seat head of an eccentric contact seat, thereby obtaining the second intermediate bar stock. The second intermediate bar stock has a cylindrical seat head and a shaft portion coaxial with the seat head that extends from one end of the seat head to one side. A third die is provided, the third die having a first part that provides rigid support to the shaft portion of the second intermediate bar stock and a second part that provides elastic support to the shaft portion of the second intermediate bar stock; A third punch is provided, which has a rigidly pressing first part and an elastically pressing second part, wherein the rigidly pressing first part corresponds to the elastically supporting second part of the third die, and the elastically pressing second part corresponds to the rigidly supporting first part of the third die. The shaft of the second intermediate bar is placed horizontally in the first and second parts of the third die, such that the seat of the second intermediate bar is located on one side of the first part and abuts against the side of the first part. After aligning the third punch and the third die, the third punch is pressed down to extrude the axial portion of the second intermediate bar. The first part of the third die and the second part of the third punch together fix the axial portion of the second intermediate bar near the seat head. The second part of the third die and the first part of the third punch together cause the axial portion of the second intermediate bar away from the seat head to shift in the pressing direction of the third punch, thereby forming an eccentric contact seat product.

2. The manufacturing method according to claim 1, wherein the first part of the third die is a first support block for supporting the shaft portion of the second intermediate bar stock, the upper end of the first support block is formed with a semi-circular or nearly semi-circular groove, the diameter of the groove being equal to or slightly larger than the diameter of the first section of the shaft portion of the eccentric contact, and the length of the groove being equal to the length of the first section of the shaft portion of the eccentric contact; the second part of the third die includes a second support block for supporting the shaft portion of the second intermediate bar stock and a third support block connected to the second support block via a spring and a threaded connector, the third support block is formed with a stepped hole, one end of the threaded connector with a larger radial dimension can move axially in the stepped hole of the third support block with a larger radial dimension and be stopped by the stepped surface of the stepped hole, the other end of the threaded connector is fixedly connected to the second support block by threads, and the spring connected between the second support block and the third support block in the assembled state is in a compressed state; the upper end of the second support block is formed with a semi-circular or nearly semi-circular groove, the diameter of the groove being equal to or slightly larger than the diameter of the second section of the shaft portion of the eccentric contact, and the central axis of the groove of the second support block coincides with the central axis of the groove of the first support block.

3. The manufacturing method according to claim 2, wherein the first part of the third punch is a first pressure block, the lower end of the first pressure block is formed with a semi-circular or nearly semi-circular groove, the diameter of which is equal to or slightly larger than the diameter of the second section of the shaft portion of the eccentric contact; the second part of the third punch includes a second pressure block corresponding to the first support block of the third die and a third pressure block connected to the second pressure block via a spring and a threaded connector, the third pressure block is formed with a stepped hole, the end of the threaded connector with a larger radial dimension can move axially in the stepped hole of the third pressure block and be stopped by the stepped surface of the stepped hole, the other end of the threaded connector is fixedly connected to the second pressure block by a thread, and the spring connected between the second pressure block and the third pressure block is in a compressed state in the assembled state; the lower end of the second pressure block is formed with a semi-circular or nearly semi-circular groove, the diameter of which is equal to or slightly larger than the diameter of the first section of the shaft portion of the eccentric contact, the length of which is equal to the length of the first section of the shaft portion of the eccentric contact, and the central axis of the groove of the second pressure block coincides with the central axis of the groove of the first pressure block; Before the third punch is pressed down, the shaft of the second intermediate bar is placed horizontally in the groove of the first support block and the second support block, so that the seat of the second intermediate bar is located on one side of the first support block and abuts against the side of the first support block.

4. The manufacturing method according to claim 1, wherein the truncated conical cavity of the first punch has a first taper and a second taper from the bottom to the opening, the first taper being smaller than the second taper.

5. The manufacturing method according to claim 4, wherein the first taper is 1.5° and the second taper is 3.5°.

6. The manufacturing method according to claim 5, wherein the dimension obtained by subtracting the height of the first tapered cavity from the height of the portion of the round bar billet not placed in the first die is equal to twice the diameter of the round bar billet.

7. The manufacturing method according to claim 1, wherein the volume of the truncated conical cavity of the first punch is 65%-80% of the volume of the eccentric contact seat head.

8. The manufacturing method according to claim 3, wherein the spring constant of the spring in the second part of the third die cavity is less than the spring constant of the spring in the second part of the third punch.

9. The manufacturing method according to claim 8, wherein the spring in the second part of the third die cavity is a helical spring, and the spring in the second part of the third punch cavity is a disc spring.

10. The manufacturing method according to claim 3, wherein the threaded connector is a bolt or screw.

Images