Silver-carbon electric contact material hot extrusion forming die

Abstract

The utility model relates to a silver-carbon electric contact material hot extrusion forming die which comprises a die plate, at least one axially-through mounting through hole is formed in the die plate, a female die is installed in the mounting through hole in a limiting mode, and an axially-through extrusion hole is formed in the center of the female die. The extrusion hole comprises a conical extrusion channel and a sizing channel which are concentrically arranged and communicated in the direction from the feeding end to the discharging end, the hole diameter of the conical extrusion channel is decreased in the direction from the feeding end to the discharging end, and the diameter of the sizing channel is equal in the direction from the feeding end to the discharging end. The female die comprises a first female die with a circular extrusion hole radial section, and / or a second female die with an elliptical extrusion hole radial section, and / or a third female die with a polygonal extrusion hole radial section. When part of the dies are damaged, only the corresponding dies need to be replaced, so that the use cost of the dies is reduced; and meanwhile, the female dies with suitable extrusion hole section shapes can be flexibly replaced or combined according to forming requirements, and the application flexibility is high.

Description

Technical Field

[0001] The utility model relates to the technical field of forming molds, and particularly relates to a hot extrusion forming mold for silver-carbon electric contact materials. Background Art

[0002] Silver-carbon electric contact materials prepared from carbon-based materials such as graphite, graphene, and carbon fiber and silver have excellent anti-welding properties and low resistivity, and are widely used in low-voltage electrical appliances (especially switches such as miniature circuit breakers MCB and molded case circuit breakers MCCB). There are two common manufacturing processes for silver-carbon electric contact materials: one is to mix powders and then use a mold for pressing and forming, followed by sintering and repressing to complete the production; the other is to mix powders, press into ingots, sinter, obtain the required shape by hot extrusion, and then obtain the final product through processes such as cutting, decarburization, and splitting. The quality of hot extrusion directly affects the quality and yield of the product. Traditional hot extrusion molds are of an integral structure. When damaged, the whole mold needs to be replaced, resulting in a relatively high mold cost. Moreover, the die holes are single and cannot be flexibly adjusted according to the forming requirements. Content of the Utility Model

[0003] The purpose of the utility model is to overcome the deficiencies existing in the prior art and provide a hot extrusion forming mold for silver-carbon electric contact materials.

[0004] The technical solution adopted by the utility model is as follows: A hot extrusion forming mold for silver-carbon electric contact materials includes a template. At least one axially penetrating installation through hole is provided on the template, and a female die is installed in the installation through hole in a limited manner. An axially penetrating extrusion hole is provided at the center of the female die.

[0005] The extrusion hole has a feed end and a discharge end. The extrusion hole includes a conical extrusion channel and a sizing channel that are concentrically arranged and connected in the direction from the feed end to the discharge end. The diameter of the conical extrusion channel becomes smaller in the direction from the feed end to the discharge end, and the sizing channel has an equal diameter in the direction from the feed end to the discharge end.

[0006] The female die includes a first female die with a circular radial cross-section of the extrusion hole, and / or a second female die with an elliptical radial cross-section of the extrusion hole, and / or a third female die with a polygonal radial cross-section of the extrusion hole.

[0007] Preferably, at least two axially penetrating installation through holes are provided on the template, and the installation through holes are symmetrically distributed about the axis of the template.

[0008] Preferably, the installation through hole sequentially includes a first positioning groove portion and a second discharge hole portion that are concentrically arranged in the direction from the feed end to the discharge end. The diameter of the second discharge hole portion is smaller than that of the first positioning groove portion and forms a limiting step therewith.

[0009] The outer periphery of the female die has a first cylindrical surface that fits the shape of the first positioning groove portion. The bottom of the female die abuts against the limiting step and forms a limiting fit therewith.

[0010] Preferably, the fitting clearance between the first positioning groove portion and the first cylindrical surface is 0.01 - 0.03 mm.

[0011] Preferably, a draft angle is provided on the outer periphery of the bottom of the first positioning groove portion.

[0012] Preferably, the conical extrusion channel is connected to the sizing channel. Chamfered corners are provided at the junction of the conical extrusion channel and the sizing channel and at the connection of the conical extrusion channel and the feeding end. The size of the chamfered corner is C0.5 - 3.0 mm.

[0013] Preferably, rounded corners are provided at the connection of the conical extrusion channel and the feeding end. The size of the rounded corner is R0.5 - 3.0 mm.

[0014] Preferably, the die angle of the conical extrusion channel is 93° - 130°.

[0015] Preferably, the diameter of the template is 3.0 - 10.0 times the diameter of the first positioning groove portion, and the height of the template is 1.5 - 5.0 times the depth of the first positioning groove portion; the diameter of the second discharge hole portion is 1.05 - 5.0 times the diameter or the longest diagonal of the sizing channel.

[0016] Preferably, the depth of the sizing channel is 0.5 - 5.5 mm.

[0017] The beneficial effects of the present utility model are as follows: This device decomposes the traditional die into a female die and a template. When part of the die is damaged, only the corresponding die needs to be replaced, thereby reducing the die usage cost; at the same time, the female die with a suitable cross-sectional shape of the extrusion hole can be flexibly replaced or combined according to the forming requirements, and the application flexibility is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, obtaining other drawings based on these drawings still belongs to the scope of the present utility model.

[0019] Figure 1 is a perspective view of Embodiment 1 of the present utility model;

[0020] Figure 2 is a front view sectional view of Embodiment 1 of the present utility model;

[0021] Figure 3 Front elevation sectional view of the template in Embodiment 1 of the present utility model;

[0022] Figure 4 Front elevation sectional view of the female die in Embodiment 1 of the present utility model;

[0023] Figure 5 Top view of the template in Embodiment 1 of the present utility model;

[0024] Figure 6 Top view of the template in Embodiment 2 of the present utility model;

[0025] Figure 7 Top view of the template in Embodiment 3 of the present utility model;

[0026] Figure 8 Top view of the template in Embodiment 4 of the present utility model;

[0027] Figure 9 Top view of the template in Embodiment 5 of the present utility model;

[0028] Figure 10 Top view of the template in Embodiment 6 of the present utility model;

[0029] In the figure, 1 is the template; 2 is the female die; 11 is the installation through-hole; 21 is the extrusion hole; 22 is the first cylindrical surface; 111 is the first positioning groove part; 112 is the second discharge hole part; 113 is the limiting step; 201 is the first female die; 202 is the second female die; 203 is the third female die; 211 is the feeding end; 212 is the discharging end; 213 is the conical extrusion channel; 214 is the sizing channel; 215 is the chamfer; 216 is the fillet; 1111 is the draft angle. Detailed implementation manners

[0030] To make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0031] It should be noted that all the expressions using "first" and "second" in the embodiments of the present utility model are used to distinguish two entities or parameters with the same name but different identities. It can be seen that "first" and "second" are only for the convenience of expression and should not be construed as a limitation on the embodiments of the present utility model. This will not be elaborated one by one in the subsequent embodiments.

[0032] The directional and positional terms mentioned in the present utility model, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "top", "bottom", "side", etc., are only with reference to the directions or positions in the accompanying drawings. Therefore, the directional and positional terms used are for explaining and understanding the present utility model, rather than limiting the protection scope of the present utility model.

[0033] Example 1

[0034] As shown Figures 1 to 5 in the figure, in an embodiment of the present utility model, a hot extrusion forming die for a silver-carbon electric contact material includes a template 1. Four axially penetrating mounting through holes 11 are provided on the template 1, and the mounting through holes 11 are symmetrically distributed about the axis of the template 1. A female die 2 is limitedly mounted in the mounting through hole 11. An axially penetrating extrusion hole 21 is provided at the center of the female die 2.

[0035] The extrusion hole 21 has a feed end 211 and a discharge end 212. The extrusion hole 21 includes a conical extrusion channel 213 and a sizing channel 214 that are concentrically arranged and connected in the direction from the feed end 211 to the discharge end 212. The conical extrusion channel 213 has a smaller aperture in the direction from the feed end 211 to the discharge end 212, and the sizing channel 214 has an equal diameter in the direction from the feed end 211 to the discharge end 212.

[0036] The female die 2 includes a first female die 201 with a circular radial cross-section of the extrusion hole 21, and / or a second female die 202 with an elliptical radial cross-section of the extrusion hole 21, and / or a third female die 203 with a polygonal radial cross-section of the extrusion hole 21.

[0037] With this setting, the traditional die is decomposed into a female die and a template. When part of the die is damaged, only the corresponding die needs to be replaced, thus reducing the die usage cost; at the same time, the female die with a suitable cross-sectional shape of the extrusion hole can be flexibly replaced or combined according to the forming requirements, and the application flexibility is high.

[0038] The mounting through hole 11 sequentially includes a first positioning groove portion 111 and a second discharge hole portion 112 that are concentrically arranged in the direction from the feed end 211 to the discharge end 212. The diameter of the second discharge hole portion 112 is smaller than that of the first positioning groove portion 111 and forms a limiting step 113 therewith.

[0039] The outer periphery of the female die 2 has a first cylindrical surface 22 that is shape-fitted to the first positioning groove portion 111. The bottom of the female die 2 abuts against the limiting step 113 and forms a limiting fit therewith.

[0040] After the silver-carbon electric contact material is heated and under the action of pressure, it enters from the feed end. Under the action of the conical extrusion channel, the flow direction is changed, and it is formed and discharged through the sizing channel, and finally the extrusion is completed through the second discharge hole portion.

[0041] The female die is limitedly mounted on the limiting step, which is convenient for disassembly and assembly, and at the same time standardizes the assembly direction of the female die and the template.

[0042] The fitting clearance between the first positioning groove portion 111 and the first cylindrical surface 22 is 0.01 - 0.03 mm.

[0043] This parameter setting takes into account both the convenience of disassembly and assembly and the stability of installation cooperation.

[0044] A draft angle 1111 is provided on the outer periphery of the bottom of the first positioning groove 111 .

[0045] The conical extrusion channel 213 is connected to the sizing channel 214. The junction between the conical extrusion channel 213 and the sizing channel 214 and the junction between the conical extrusion channel 213 and the feed end 211 are both provided with chamfers 215. The size of the chamfers 215 is C0.5-3.0 mm.

[0046] A chamfer 216 is provided at the connection point between the tapered extrusion channel 213 and the feed end 211 , and the size of the chamfer 216 is R0.5-3.0 mm.

[0047] The die entry angle of the tapered extrusion channel 213 is 93° to 130°.

[0048] The diameter of the template 1 is 3.0 to 10.0 times the diameter of the first positioning groove 111 , and the height of the template 1 is 1.5 to 5.0 times the depth of the first positioning groove 111 .

[0049] The diameter of the second discharge hole 112 is 1.05 to 5.0 times the diameter of the sizing channel 214 or the longest diagonal.

[0050] The depth of the sizing channel 214 is 0.5-5.5 mm.

[0051] In this embodiment, the matching clearance between the die 2 and the first positioning groove portion 111 is 0.02mm, the entry angle of the tapered extrusion channel 213 is 130°, the radial cross-section of the sizing channel 214 is circular, the diameter of the sizing channel 214 is Φ5mm, the depth of the sizing channel 214 is 4.0mm, the size of the chamfer 216 is R2.0mm, the size of the chamfer 215 is C2.0mm, the diameter of the template 1 is 100.0mm, the thickness of the template 1 is 50.0mm, the diameter of the first positioning groove portion 111 is 20.0mm, the depth of the first positioning groove portion 111 is 10.0mm, the matching clearance between the draft angle 1111 and the chamfer 215 is 0.02mm, and the diameter of the second discharge hole portion 112 is 6.0mm.

[0052] By adjusting the parameters of the conical extrusion channel and the sizing channel of the die in accordance with this embodiment, the problems of cracking in the appearance, shrinkage cavities and aggregation of the metallographic structure of the silver-carbon electrical contact material can be improved, and the yield rate and quality stability can be significantly improved.

[0053] Example 2

[0054] As Figure 6 shown, in the embodiment of the present utility model, a hot extrusion forming die for silver-carbon electrical contact material, the difference from Embodiment 1 is only that an axially through installation through-hole 11 is provided at the center of the template 1.

[0055] Example 3

[0056] As Figure 7 shown, in the embodiment of the present utility model, a hot extrusion forming die for silver-carbon electrical contact material, the difference from Embodiment 1 is only that two axially through installation through-holes 11 are provided on the template 1, and the two installation through-holes 11 are symmetrically distributed about the axis of the template 1.

[0057] Example 4

[0058] As Figure 8 shown, in the embodiment of the present utility model, a hot extrusion forming die for silver-carbon electrical contact material, the difference from Embodiment 1 is only that three axially through installation through-holes 11 are provided on the template 1, and the three installation through-holes 11 are symmetrically distributed about the axis of the template 1.

[0059] Example 5

[0060] As Figure 9 shown, in the embodiment of the present utility model, a hot extrusion forming die for silver-carbon electrical contact material, the difference from Embodiment 1 is only that five axially through installation through-holes 11 are provided on the template 1, and the five installation through-holes 11 are symmetrically distributed about the axis of the template 1.

[0061] Example 6

[0062] As Figure 10 shown, in the embodiment of the present utility model, a hot extrusion forming die for silver-carbon electrical contact material, the difference from Embodiment 1 is only that six axially through installation through-holes 11 are provided on the template 1, and the six installation through-holes 11 are symmetrically distributed about the axis of the template 1.

[0063] The above-disclosed are only the preferred embodiments of the present utility model. Of course, the scope of the rights of the present utility model cannot be limited thereby. Therefore, equivalent changes made according to the claims of the present utility model still fall within the scope covered by the present utility model.

Claims

1. A hot extrusion molding die for a silver-carbon electrical contact material, comprising a die plate (1), characterized in that: The template (1) is provided with at least one axially penetrating mounting through hole (11), a concave die (2) is positionally mounted in the mounting through hole (11), and an axially penetrating extrusion hole (21) is provided at the center of the concave die (2). The extrusion hole (21) has a feed end (211) and a discharge end (212); the extrusion hole (21) comprises a concentrically arranged and connected tapered extrusion channel (213) and a sizing channel (214) in a direction from the feed end (211) to the discharge end (212); the diameter of the tapered extrusion channel (213) decreases in a direction from the feed end (211) to the discharge end (212); the diameter of the sizing channel (214) is the same in a direction from the feed end (211) to the discharge end (212); The concave die (2) comprises a first concave die (201) whose radial cross section of the extrusion hole (21) is circular, and / or a second concave die (202) whose radial cross section of the extrusion hole (21) is elliptical, and / or a third concave die (203) whose radial cross section of the extrusion hole (21) is polygonal.

2. The hot extrusion forming die for silver-carbon electrical contact material according to claim 1, characterized in that: The template (1) is provided with at least two axially penetrating mounting through holes (11), and the mounting through holes (11) are symmetrically distributed about the axis of the template (1).

3. The hot extrusion forming die for silver-carbon electrical contact material according to claim 1, characterized in that: The mounting through hole (11) comprises a first positioning groove portion (111) and a second discharging hole portion (112) which are arranged concentrically in the direction from the feeding end (211) to the discharging end (212); the second discharging hole portion (112) has a smaller diameter than the first positioning groove portion (111) and forms a limiting step (113) therewith. The outer periphery of the concave die (2) has a first cylindrical surface (22) that matches the shape of the first positioning groove (111), and the bottom of the concave die (2) abuts against the limiting step (113) and forms a limiting fit therewith.

4. A hot extrusion forming die for silver-carbon electrical contact material according to claim 3, characterized in that: The matching clearance between the first positioning groove (111) and the first column surface (22) is 0.01-0.03 mm.

5. The hot extrusion forming die for silver-carbon electrical contact material according to claim 3, characterized in that: A draft angle (1111) is provided on the outer periphery of the bottom of the first positioning groove portion (111).

6. The hot extrusion forming die for silver-carbon electrical contact material according to claim 1, characterized in that: The conical extrusion channel (213) and the sizing channel (214) are connected, and a chamfer (215) is provided at the junction of the conical extrusion channel (213) and the sizing channel (214) and at the junction of the conical extrusion channel (213) and the feed end (211), and the size of the chamfer (215) is C0.5-3.0 mm.

7. A hot extrusion forming die for silver-carbon electrical contact material according to claim 6, characterized in that: A chamfer (216) is provided at the connection point between the conical extrusion channel (213) and the feed end (211), and the size of the chamfer (216) is R0.5-3.0 mm.

8. The hot extrusion forming die for silver-carbon electrical contact material according to claim 1, characterized in that: The die entry angle of the tapered extrusion channel (213) is 93° to 130°.

9. The hot extrusion forming die for silver-carbon electrical contact material according to claim 3, characterized in that: The diameter of the template (1) is 3.0 to 10.0 times the diameter of the first positioning groove (111), and the height of the template (1) is 1.5 to 5.0 times the depth of the first positioning groove (111); the diameter of the second discharge hole (112) is 1.05 to 5.0 times the diameter of the sizing channel (214) or the longest diagonal.

10. The hot extrusion forming die for silver-carbon electrical contact material according to claim 1, characterized in that: The depth of the sizing channel (214) is 0.5-5.5 mm.

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