Method of manufacturing a profiled contact carrier

Abstract

The application discloses a manufacturing method of a special-shaped contact seat, which comprises the following steps: providing a round bar blank with a circular truncated cone; forming the round bar blank into an intermediate bar with a straight bar part, an annular flange and a circular truncated cone through a first extrusion process; forming the intermediate bar into a semi-finished product with a contact seat contour through a second extrusion process; and finishing the semi-finished product to remove excess parts, so as to form a contact seat product. The manufacturing method is reliable and practical, and the special-shaped contact seat with reliable performance is manufactured by means of combined methods such as step-by-step extrusion and the like through the design of a specific blank shape, and meanwhile, material waste is avoided to the greatest extent.

Description

TECHNICAL FIELD

[0001] The present invention relates generally to a manufacturing method or process of a contact holder. BACKGROUND

[0002] Various forms of electrical connectors, such as high voltage switches and the like, often use a profiled contact holder with a flange, which is usually manufactured by a one-step extrusion forming + machining method. Since the flange structure needs to be formed on the contact holder, a considerable amount of metal material will be wasted during machining, thus increasing the cost of the part. SUMMARY

[0003] It is an object of the present invention to provide a manufacturing method of a profiled contact holder, which at least minimizes the waste of metal material.

[0004] The profiled contact holder to be manufactured according to the present invention has an integrally formed cylindrical portion, a (frusto-)conical portion and a flange portion (annular flange) between the cylindrical portion and the conical portion, wherein the upper end of the cylindrical portion forms a receiving opening of the contact holder, the tapered lower end of the conical portion forms a planar circular bottom of the contact holder, the outer diameter of the flange portion is larger than the outer diameter of the cylindrical portion, the outer diameter of the cylindrical portion is larger than the maximum outer diameter of the conical portion, the cylindrical portion has a substantially constant inner diameter (and thus defines a cylindrical inner surface of the contact holder) which tapers towards the flange portion to jointly define a (frusto-)conical inner surface of the contact holder with the flange portion and the conical portion.

[0005] The manufacturing method according to the present invention comprises:

[0006] providing a (solid) round bar blank and forging one end of the round bar blank to form a tapered coaxial conical frustum, wherein the maximum diameter of the conical frustum is (slightly) smaller than the diameter of the round bar blank;

[0007] providing a first female die having a cylindrical upper cavity of a larger diameter and a cylindrical lower cavity of a smaller diameter, wherein the transition (frusto-)conical surface between the cylindrical upper cavity and the cylindrical lower cavity corresponds to the diameter of the round bar blank (is substantially equal to the diameter of the round bar blank);

[0008] providing a first male die having an outer diameter corresponding to the diameter of the round bar blank, and a lower end forming a (frusto-conical) cavity corresponding to the outer shape of the conical frustum of the round bar blank;

[0009] providing a first round pad having a diameter corresponding to the diameter of the cylindrical lower cavity of the first female die;

[0010] placing the round bar blank into the cylindrical upper cavity of the first female die with the conical frustum facing upwards, and placing the first round pad into the cylindrical lower cavity of the first female die;

[0011] placing the first male die into the cylindrical upper cavity of the first female die with the cavity of the first male die abutting the conical frustum of the round bar blank;

[0012] The first punch is pressed down until the round bar blank contacts the first round pad, thereby forming an intermediate bar having a straight bar portion, an annular flange, and a circular conical shoulder;

[0013] A second die is provided, which has a larger-diameter cylindrical upper cavity and a smaller-diameter cylindrical lower cavity, with a transition (frustoconical) surface formed between the cylindrical upper and lower cavities, wherein the diameter of the cylindrical upper cavity corresponds to the diameter (outer diameter) of the annular flange of the intermediate bar, and the diameter of the cylindrical lower cavity corresponds to the diameter (outer diameter) of the planar circular base of the contact seat;

[0014] A second punch is provided, which has an outer shape corresponding to the shape of the inner cavity of the contact seat and thus has a straight bar portion and a tapered portion;

[0015] A second round pad is provided, which has a diameter corresponding to the diameter of the cylindrical lower cavity of the second die;

[0016] An annular fixing sleeve is provided, which has an outer diameter corresponding to the diameter of the cylindrical upper cavity of the second die and an inner diameter corresponding to the diameter of the cylindrical lower cavity of the first die (the diameter of the straight bar portion of the intermediate bar);

[0017] The intermediate bar is placed in the second die, and the second round pad is placed in the cylindrical lower cavity of the second die, with the annular flange located at the bottom of the cylindrical upper cavity of the second die and the circular conical shoulder abutting the second round pad;

[0018] The annular fixing sleeve is inserted into the second die, with the outer side abutting the inner wall of the cylindrical upper cavity of the second die and the inner side abutting the straight bar portion of the intermediate bar, and the lower end abutting the annular flange of the intermediate bar;

[0019] The second punch is centrally placed in the cylindrical upper cavity of the second die, with the bottom surface of the tapered portion contacting the corresponding end surface of the straight bar portion of the intermediate bar;

[0020] The second punch is pressed down until a semi-finished product having the profile of the contact seat is formed; and

[0021] The semi-finished product is finished to remove excess portions, thereby forming a contact seat product.

[0022] According to the present application, the annular fixing sleeve is preferably a two- piece fixing sleeve to facilitate placement and removal.

[0023] According to the present application, the round bar blank is preferably made of a red copper material containing the following components (by volume fraction): W: 10%; carbon fiber: 0.01%; Cr: 0.2%; and the balance Cu. This material not only has good electrical conductivity, but is also very advantageous for step-by-step extrusion forming.

[0024] In the case of using the above-mentioned red copper material, the round bar blank is heated to a first deformation temperature and then placed in the first die. The first deformation temperature is preferably 835°C to 865°C, and more preferably 850°C. In addition, the intermediate bar is heated to a second deformation temperature and then placed in the second die. The second deformation temperature is preferably 870°C to 890°C, and more preferably 880°C. The above-mentioned different deformation temperatures are not only suitable for the corresponding extrusion process, but also make the extruded product have good forging wear resistance.

[0025] According to the present application, the intermediate bar can be taken out of the first die by pushing up the first round pad. In addition, the semi-finished product can also be taken out of the second die by pushing up the second round pad. This taking-out method is convenient and will not damage the product.

[0026] The manufacturing method of the present application is reliable and practical. By designing a specific blank shape, and by means of combined steps such as step-by-step extrusion, a reliable performance profile contact seat is obtained, and material waste is also minimized. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A structural schematic view of a contact seat manufactured according to the present application is shown;

[0028] Figure 2 A schematic view of the first extrusion process of the manufacturing method according to the present application is shown; and

[0029] Figure 3 A schematic view of the second extrusion process of the manufacturing method according to the present application is shown. DETAILED DESCRIPTION

[0030] The present application will be described in detail below with reference to the accompanying drawings. Those skilled in the art will understand that the embodiments described below are only exemplary of the present application, and are not intended to limit it in any way.

[0031] As shown in Figure 1 The profiled contact seat 101 to be manufactured according to the present application has an integral cylindrical portion 102, a (frusto-)conical portion 104, and a convex ring portion 103 (annular flange) between the cylindrical portion 102 and the conical portion 104. The upper end of the cylindrical portion 102 forms a circular receiving opening of the contact seat, and the tapered lower end of the conical portion 104 forms a planar circular bottom of the contact seat. The outer diameter of the convex ring portion 103 is greater than that of the cylindrical portion 102, and the outer diameter of the cylindrical portion 102 is greater than the maximum outer diameter of the conical portion 104. The cylindrical portion 102 has a substantially constant inner diameter (and thus defines a cylindrical inner surface of the contact seat) and a tapered inner diameter near the convex ring portion 103 to jointly define a (frusto-)conical inner surface of the contact seat with the convex ring portion 103 and the conical portion 104.

[0032] The special-shaped contact seat 101 is especially suitable for receiving the contacts (not shown) of an electrical connector, and the convex ring portion 103 facilitates fixed installation. In one specific example of the present application, the contact seat 101 is made of red copper material, and its composition (in volume fraction) is as follows: W: 10%; carbon fiber: 0.01%; Cr: 0.2%; and the balance Cu.

[0033] First, the above-mentioned red copper material is forged to form a round bar blank 202 having a tapered coaxial conical frustum at one end. The maximum diameter of the conical frustum is slightly smaller than the diameter of the round bar blank.

[0034] Figure 2 A first extrusion process according to the method of manufacturing the contact seat of the present application is shown. As shown, the process employs a die including a first punch 201, a first recess 203, and a first round pad 206, and other auxiliary / fixed parts are not shown in detail.

[0035] As shown, the first recess 203 has a larger-diameter cylindrical upper cavity and a smaller-diameter cylindrical lower cavity. A transition (frustoconical) surface is formed between the cylindrical upper cavity and the cylindrical lower cavity, wherein the diameter of the cylindrical upper cavity corresponds to (i.e., is substantially equal to) the (maximum) diameter of the round bar blank 202. The outer diameter of the first punch 201 also corresponds to the diameter of the round bar blank 202, and the lower end of the first punch 201 forms a (frustoconical) cavity corresponding to the outer shape of the conical frustum of the round bar blank 202. The diameter of the first round pad 206 corresponds to the diameter of the cylindrical lower cavity of the first recess 203.

[0036] The first round pad 206 is fixedly placed in the cylindrical lower cavity of the first recess 203, and the round bar blank 202 is heated to 850°C and then placed in the cylindrical upper cavity of the first recess 203 with the conical frustum facing upward.

[0037] Next, the first punch 201 is placed in the cylindrical upper cavity of the first recess 203 with its cavity abutting the conical frustum of the round bar blank 202.

[0038] Then, the first punch 201 is pressed downward until the round bar blank 2002 contacts the first round pad 206, thereby forming an intermediate bar 205 having a straight rod portion, an annular flange, and a conical frustum.

[0039] Figure 2 The dashed line 204 shown in the middle represents the actual position where the conical portion 104 of the contact seat 101 should be located. At this time, the conical frustum of the round bar blank 202 is slightly larger in taper angle and slightly lower in height than the conical portion 104 of the contact seat 101.

[0040] Afterwards, the intermediate bar 205 can be taken out of the first recess 203 by upwardly pushing the first round pad 206.

[0041] Figure 3The schematic diagram of the second extrusion process of the manufacturing method according to the present invention is shown. As shown in the figure, the mold used in this process includes: a second punch 301, a second die 302, a second circular pad 306 and an annular fixing sleeve 303. Other auxiliary / fixing components are also not shown.

[0042] As shown in the figure, the second die 302 has a cylindrical upper cavity with a larger diameter and a cylindrical lower cavity with a smaller diameter, with a transition (truncated) conical surface formed between the upper and lower cavities. The diameter of the upper cylindrical cavity corresponds to the outer diameter of the annular flange of the intermediate bar 305 (the same as the intermediate bar 205 in the first step), while the diameter of the lower cylindrical cavity corresponds to the outer diameter of the flat circular bottom of the contact base 101. The outer shape of the second punch 301 corresponds to the inner shape of the contact base 101 and therefore has a straight rod portion and a tapered portion. The diameter of the second circular washer 306 corresponds to the diameter of the cylindrical lower cavity of the second die 302. The outer diameter of the annular fixing sleeve 303 corresponds to the diameter of the cylindrical upper cavity of the second die 302, while the inner diameter corresponds to the diameter of the cylindrical lower cavity of the first die 203 (the diameter of the straight rod portion of the intermediate bar 305).

[0043] Place the second circular pad 206 into the cylindrical lower cavity of the second die; and heat the intermediate bar 205 to 880°C and place it into the second die 302 so that its annular flange is located at the bottom of the cylindrical upper cavity of the second die 302, and its frustum abuts the second circular pad 306.

[0044] Next, the two-half annular fixing sleeve 303 is inserted into the second die 302 , with the outer side close to the inner wall of the cylindrical upper cavity of the second die 302 , the inner side close to the straight rod part of the middle bar 305 , and the lower end abutting the annular flange of the middle bar 305 .

[0045] Then, the second punch 301 is placed centrally in the cylindrical upper cavity of the second die 302 , with the bottom surface of the tapered portion thereof contacting the corresponding end surface of the straight rod portion of the intermediate bar 305 .

[0046] Next, the second punch 301 is pressed down until a semi-finished product 304 having a contact seat profile is formed.

[0047] The semi-finished product 304 is slightly different from the finished product or the finished contact seat 101: Figure 3 Extrusion may produce excess material or redundant parts in the regions 307 and 308. The redundant parts are then removed by a suitable finishing process such as machining to form the finished contact holder 101 of the present invention.

[0048] As described above, the present invention manufactures a special-shaped contact holder with reliable performance by cleverly designing the raw materials and the shape of the blanks, and by designing a continuous first extrusion process and a second extrusion process, while avoiding material waste to the greatest extent.

Claims

1. A method for manufacturing a special-shaped contact holder, the contact holder comprising an integrally formed cylindrical portion, a conical portion, and a convex ring portion located between the cylindrical portion and the conical portion, wherein the upper end of the cylindrical portion forms a receiving opening of the contact holder, the tapered lower end of the conical portion forms a planar circular bottom portion of the contact holder, the outer diameter of the convex ring portion is greater than the outer diameter of the cylindrical portion, and the outer diameter of the cylindrical portion is greater than the maximum outer diameter of the conical portion, the cylindrical portion having a substantially constant inner diameter and tapering as it approaches the convex ring portion to define, together with the convex ring portion and the conical portion, a tapered inner surface of the contact holder, the method comprising: Providing a round bar blank and forging one end of the round bar blank into a tapered coaxial frustum, wherein the maximum diameter of the frustum is smaller than the diameter of the round bar blank; Providing a first die, the first die having a cylindrical upper cavity with a larger diameter and a cylindrical lower cavity with a smaller diameter, a transition conical surface being formed between the cylindrical upper cavity and the cylindrical lower cavity, wherein the diameter of the cylindrical upper cavity corresponds to the diameter of the round bar blank; Providing a first punch, wherein the outer diameter of the first punch also corresponds to the diameter of the round bar blank, and the lower end of the first punch forms a concave cavity corresponding to the outer shape of the truncated cone of the round bar blank; providing a first circular pad having a diameter corresponding to the diameter of the cylindrical lower cavity of the first female mold; After heating the round rod blank to a first deformation temperature, the round rod blank is placed in the cylindrical upper cavity of the first die with the frustum facing upward, and the first round pad is placed in the cylindrical lower cavity of the first die; The first punch is placed into the cylindrical upper cavity of the first die, and the cavity is made to fit the cone of the round bar blank; Pressing the first punch downward until the round bar blank contacts the first round pad, thereby forming an intermediate bar having a straight bar portion, an annular flange and a frustum; Providing a second die, the second die having a cylindrical upper cavity with a larger diameter and a cylindrical lower cavity with a smaller diameter, wherein a transition conical surface is formed between the cylindrical upper cavity and the cylindrical lower cavity, wherein the diameter of the cylindrical upper cavity corresponds to the diameter of the annular flange of the intermediate bar, and the diameter of the cylindrical lower cavity corresponds to the diameter of the flat circular bottom of the contact seat; Providing a second punch, the outer shape of the second punch corresponding to the inner shape of the contact seat and thus having a straight rod portion and a tapered portion; providing a second circular pad having a diameter corresponding to the diameter of the cylindrical lower cavity of the second female mold; Providing an annular fixing sleeve, the outer diameter of which corresponds to the diameter of the cylindrical upper cavity of the second die, and the inner diameter of which corresponds to the diameter of the cylindrical lower cavity of the first die; The intermediate bar is heated to a second deformation temperature different from the first deformation temperature and then placed in a second die. The second circular pad is placed in the cylindrical lower cavity of the second die, wherein the annular flange is located at the bottom of the cylindrical upper cavity of the second die, and the frustum abuts the second circular pad. Insert the annular fixing sleeve into the second die, with the outer side close to the inner wall of the cylindrical upper cavity of the second die, the inner side close to the straight rod part of the middle bar, and the lower end abutting the annular flange of the middle bar; The second punch is placed centrally in the cylindrical upper cavity of the second die, with the bottom surface of the tapered portion contacting the corresponding end surface of the straight rod portion of the intermediate bar stock; Pressing the second punch downward until a semi-finished product having a contact seat profile is formed; and Finishing the semi-finished product to remove excess parts to form the contact seat product, The annular fixing sleeve is a two-half fixing sleeve.

2. The manufacturing method according to claim 1, wherein the round bar blank is made of a material containing the following components in volume fractions: W: 10%; carbon fiber: 0.01%; Cr: 0.2%; the balance is Cu.

3. The manufacturing method according to claim 2, wherein the first deformation temperature is 835°C to 865°C.

4. The manufacturing method according to claim 3, wherein the second deformation temperature is 870°C to 890°C.

5. The manufacturing method according to claim 1, wherein the intermediate bar is removed from the first die by pushing the first circular pad upward.

6. The manufacturing method according to claim 1, wherein the semi-finished product is removed from the second die by pushing the second circular pad upward.

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