A high compression angle drawing die for beryllium copper alloy wire

Abstract

This invention discloses a high compression angle drawing die for beryllium copper alloy wire, comprising a die body. Within the die body's material processing channel, an infeed area, a first drawing section, and a second drawing section are sequentially arranged. A lubricating oil supply hole is formed on the side wall of the infeed area, and this lubricating oil supply hole is connected to an external lubricating oil supply device for wire drawing via a pipeline. A pressurized lubricating oil cavity is also formed between the end of the infeed area and the first drawing section. The minimum inner diameter of the first drawing section is larger than that of the second drawing section. A spacer cavity is formed between the first drawing section and the second drawing section. A circulation pipeline connected to the spacer cavity is provided on the die body, and the circulation pipeline is externally connected to a metallographic polishing lubricating coolant supply device. This invention enables high compression angle drawing of beryllium copper wire during drawing operations through a dual-drawing section structure, effectively ensuring high wire diameter accuracy and high surface quality of the obtained beryllium copper wire product.

Description

Technical Field

[0001] This invention relates to bar and wire processing equipment in the field of copper material production and processing technology, specifically to a high compression angle stretching die for beryllium copper alloy wire. Background Technology

[0002] As a type of copper alloy, beryllium copper has similar machinability, weldability, and polishing properties to general high-copper alloys. It also has good electrical and thermal conductivity, is non-magnetic, and has spark resistance. Furthermore, its mechanical properties, namely strength, hardness, wear resistance, and fatigue resistance, are among the best of copper alloys, making it an excellent processing material.

[0003] Similar to other common metal wire processing methods, beryllium copper wire processing is also achieved through continuous multi-stage stretching using a stretching die. Existing stretching dies for beryllium copper wire processing are mostly based on traditional copper-specific dies. These dies suffer from low efficiency, high breakage rate, and poor surface quality during the stretching process. Given the superior material properties of beryllium copper, some have improved traditional copper stretching dies by using a larger compression angle within the die. This method effectively reduces the number of stretching operations, thus improving efficiency. However, using a large compression angle increases the contact area of ​​the beryllium copper wire in the sizing zone (compression and holding sections) during stretching, leading to increased contact friction and compressive force. Without adequate lubrication, heat dissipation, and stress buffering, the wire diameter becomes difficult to control during stretching, directly affecting the quality of the finished wire and reducing the die's lifespan. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide a high compression angle drawing die for beryllium copper alloy wire, so as to overcome the defects in the above-mentioned technical background.

[0005] The technical problem solved by this invention is achieved by the following technical solution:

[0006] A high compression angle drawing die for beryllium copper alloy wire includes a die body, in which a material processing channel is formed. The material processing channel is provided with an inlet area, a first drawing section and a second drawing section in sequence along the wire processing direction. The material processing channel exits from the rear of the second drawing section.

[0007] The side wall of the feeding area is formed with a lubricating oil supply hole, which is connected to a lubricating oil supply device for stretching via an external pipeline; a pressurized lubricating oil cavity is also formed between the end of the feeding area and the first stretching part.

[0008] The minimum inner diameter of the stretching cavity of the first stretching part is larger than the minimum inner diameter of the stretching cavity of the second stretching part; the stretching cavity of the first stretching part has a complete and independent inlet section, compression section, holding section and outlet section; the stretching cavity of the second stretching part only includes an inlet section, compression section and outlet section.

[0009] The compression angle of the compression section of the first tensioning part is greater than 20°; while the compression angle of the compression section of the second tensioning part is 10±2°.

[0010] The exit chamfer of both the first stretching section and the second stretching section at the exit section is greater than 100°;

[0011] A spacer cavity is formed between the first stretching part and the second stretching part. A circulation pipeline connected to the spacer cavity is provided on the mold body. The circulation pipeline is externally connected to a metallographic polishing lubricating coolant supply device.

[0012] As a further limitation, the mold body includes a detachable mold sleeve and a mold core, and the material processing channel passes through the mold sleeve and the mold core in sequence; the material feeding area is disposed on the mold sleeve, and the first stretching area and the second stretching area are disposed on the mold core.

[0013] As a further limitation, both the first stretching portion and the second stretching portion are formed on the material processing channel in the form of a cemented carbide liner or a cemented carbide liner.

[0014] The Rockwell hardness value of the corresponding cemented carbide block or cemented carbide liner on the first stretching part is HRC64~66; the Rockwell hardness value of the corresponding cemented carbide block or cemented carbide liner on the second stretching part is 8~15% smaller than the Rockwell hardness value of the corresponding cemented carbide block or cemented carbide liner on the first stretching part.

[0015] The surface of the cemented carbide liner or cemented carbide liner in the second stretching section is plated with titanium.

[0016] As a further limitation, the feeding area is provided with a guide feeding port, which includes a first guide feeding port and a second guide feeding port. Both the first guide feeding port and the second guide feeding port are frustum-shaped structures with an isosceles trapezoidal longitudinal section, and the angle between the hypotenuse of the first guide feeding port and the horizontal plane is greater than the angle between the hypotenuse of the second guide feeding port and the horizontal plane.

[0017] The lubricating oil supply hole is located on the inclined side wall of the second guide inlet.

[0018] As a further definition, the pressurized lubricating oil chamber is an annular cavity surrounding the material processing channel.

[0019] As a further limitation, the difference between the minimum inner diameter of the first stretching portion and the minimum inner diameter of the second stretching portion is 300~1200nm.

[0020] As a further limitation, an annular buffer cavity is also formed between the partition cavity and the circulation pipeline, and the volume of the annular buffer cavity is 1 / 4 to 1 / 2 of the volume of the partition cavity.

[0021] Beneficial effects: The high compression angle drawing die for beryllium copper alloy wire of the present invention is designed with the material characteristics of beryllium copper alloy. It is suitable for drawing beryllium copper alloy wire with a wire diameter of 0.8~5.0mm under high compression angle conditions. The drawing operation is carried out through the first drawing part with a high compression angle, and the wire diameter is repaired through the second drawing part. With the use of appropriate lubricant and lubricating coolant, the contact friction of the wire during the drawing process can be effectively reduced and the heat generated during the drawing operation can be removed, which enhances the lubrication effect, reduces the wear of the die core, and is conducive to producing beryllium copper wire with high wire diameter accuracy and high surface quality. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a preferred embodiment of the present invention.

[0023] The components are: 1. Beryllium copper wire; 2. Mold sleeve; 3. Lubricating oil supply port; 4. Lubricating oil pressurization supply port; 5. Positioning insert; 6. Metallographic polishing lubricating coolant inlet pipe; 7. Annular buffer cavity; 8. Threaded assembly fastener; 9. Mold core; 10. First guide inlet; 11. Second guide inlet; 12. Pressurized lubricating oil cavity; 13. First stretching section; 14. Metallographic polishing lubricating coolant outlet pipe; 15. Spacer cavity; 16. Second stretching section. Implementation

[0024] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0025] See Figure 1 A preferred embodiment of a high compression angle drawing die for beryllium copper alloy wire is disclosed. This drawing die is specifically designed for drawing beryllium copper alloy wire to continuously draw beryllium copper alloy wires of different diameters into finer beryllium copper alloy wires. The beryllium copper alloy wire diameter suitable for this die is 0.8~5.0mm. If the wire is too thick, heat dissipation and lubrication problems still exist under the compression angle conditions of the drawing die, which can easily lead to surface defects in the drawn wire. If the wire is too thin, there is still a significant risk of wire breakage under the compression angle conditions of the drawing die.

[0026] The high compression angle drawing die for beryllium copper alloy wire includes a die sleeve 2 and a die core 9. The die sleeve 2 and the die core 9 are made of the same material, carbon tool steel or alloy tool steel, to ensure the overall structural strength and structural stability of the die body.

[0027] In this embodiment, the mold sleeve 2 has an assembly slot at the rear. The mold core 9 is assembled into the assembly slot by a detachable assembly method. In order to improve the convenience of assembly operation, in this embodiment, the mold sleeve 2 is provided with a positioning insert 5 in the assembly slot. The positioning insert 5 and the mold core 9 are provided with matching L-shaped grooves and protrusions matching the width of the L-shaped grooves at corresponding positions. After the mold core 9 is installed with the positioning insert 5 as an auxiliary positioning guide, it is rotated to the bottom so that the protrusion is rotated into the bottom of the L-shaped groove. This realizes the corresponding positioning of the mold sleeve 2 and the mold core 9 with the corresponding metallographic polishing lubricating coolant inlet pipe 6, metallographic polishing lubricating coolant outlet pipe 14, and threaded holes matching the threaded fasteners 8. Then, the threaded fasteners 8 are screwed into the aforementioned threaded holes to complete the assembly operation of the mold core 9 in the mold sleeve 2.

[0028] By replacing different mold cores 9 within the mold sleeve 2, the processing requirements for beryllium copper alloy wires of different sizes and specifications can be met. At the same time, the corresponding disassembled mold core 9 can be directly maintained, and after the corresponding first stretching part 13 or second stretching part 16 wears to a specific position, it can be scrapped as a consumable or undergo secondary processing in the mold core 9 corresponding to the first stretching part 13 or second stretching part 16.

[0029] After the mold core 9 is assembled in the mold sleeve 2, it has a concentric through hole structure. The mold body uses this hole structure as a material processing channel for beryllium copper wire to pass through and for stretching operations.

[0030] The die sleeve 2 has a guide inlet at the front end of the material processing channel area as the feeding area. The guide inlet includes a first guide inlet 10 and a second guide inlet 11 arranged in sequence. Both the first guide inlet 10 and the second guide inlet 11 are conical structures with their cone openings facing outwards to facilitate feeding. The cone angle of the first guide inlet 10 is larger than that of the second guide inlet 11, and the inner diameter of the second guide inlet 11 at the end of the cone angle is 1.05 to 1.3 times the outer diameter of the beryllium copper wire 1 to be processed. The second guide inlet 11 is a lubrication surface, and its inner side is provided with a lubricating oil supply channel 3. The lubricating oil supply channel 3 includes multiple sets arranged in a ring. These lubricating oil supply channel 3 are connected to a lubricating oil supply device, and the lubricating oil provided by the lubricating oil supply device is used as a lubricating medium to perform hydrodynamic lubrication on the circumferential surface of the beryllium copper wire 1 to be processed entering the die.

[0031] A pressurized lubricating oil cavity 12 is provided on the rear side of the mold sleeve 2 corresponding to the second guide inlet 11. The pressurized lubricating oil cavity 12 is located on the back side of the cone end of the second guide inlet 11 and is an annular cavity structure surrounding the material processing channel. The pressurized lubricating oil cavity 12 is connected to the lubricating oil pressurized supply hole 4 provided in the mold sleeve 2, and is connected to the lubricating oil supply device through the lubricating oil pressurized supply hole 4. The lubricating oil supply device uses the same lubricating oil as the lubricating oil supply hole 3. Pressure oil is supplied through the lubricating oil pressurization supply channel 4 formed in the mold sleeve 2, and the lubricating oil flow is buffered by the pressurized lubricating oil cavity 12. This ensures that the lubricating oil in the pressurized lubricating oil cavity 12 area and the material processing channel before the first stretching part 13 connected to the pressurized lubricating oil cavity 12 area are pressurized and filled with lubricating oil. During filling, the lubricating oil pressure in this area is always maintained between 0.20 and 0.35 MPa by the lubricating oil supply equipment connected to the lubricating oil pressurization supply channel 4. Under this condition, the surface of the beryllium copper wire 1 entering the stretching processing area is covered with a layer of pressurized oil film, and enters the first stretching part 13 with the assistance of the pressurized oil film. This provides lubrication for the stretching operation of the first stretching part 13 and also plays a pressure guiding role, reducing the wear of the first stretching part 13. The pressurized oil film also buffers the force on the beryllium copper wire 1 in the stretching deformation area to adapt to the material deformation of the beryllium copper wire 1 and prevent the beryllium copper wire 1 from breaking under large compression angle.

[0032] In this embodiment, the die core 9 serves as the main working structure. A first stretching section 13 and a second stretching section 16 are arranged along the processing direction in the material processing channel within the die core 9. Both the first stretching section 13 and the second stretching section 16 are hard alloy liner structures, formed on the material processing channel within the die core 9 using powder metallurgy. In other embodiments, a protrusion integrally formed with the die core 9 substrate can be formed in the material processing channel within the die core 9. Then, a hard alloy liner with a high-strength surface is formed on the surface of this protrusion using powder metallurgy to obtain the first stretching section 13 and the second stretching section 16. The stretching die, through the first stretching section 13 and the second stretching section 16, serves as the working structure for stretching the beryllium copper wire 1. After passing through the second stretching section 16, the beryllium copper wire 1 exits and, after cooling, can enter the next stretching die or the next processing stage.

[0033] Its first stretching section 13 is the main stretching structure, and the corresponding hard alloy liner has a Rockwell hardness value of HRC65. The first stretching section 13 has a complete and independent inlet section, compression section, holding section and outlet section. Its inlet section is conical to facilitate the feeding through the flared end. The compression section has an arc transition and a compression angle of 22.5° in the wire diameter compression area. The holding section is a cylindrical body with the same shape as the end of the compression section. The outlet section is conical and has an outlet chamfer of 110°.

[0034] The second stretching section 16 serves as a surface repair structure for the wire exit and also assists in stretching. The corresponding carbide liner for the second stretching section 16 has a Rockwell hardness of HRC57. The stretching cavity of the second stretching section 16 includes only an inlet section, a compression section, and an outlet section. The inlet section is tapered to facilitate guided feeding through a flared opening. The compression section has a curved transition and a 10° compression angle in the wire diameter compression area. The outlet section is also tapered and has a 110° outlet chamfer. In this embodiment, to ensure the performance of the second stretching section 16, the compression section of the second stretching section has a smaller minimum inner diameter than that of the first stretching section, with a difference of 700 nm.

[0035] In addition, a spacer cavity 15 is formed between the first stretching part 13 and the second stretching part 16. The mold core 9 is also provided with an annular buffer cavity 7 on the outer edge corresponding to the spacer cavity. The annular buffer cavity 7 concentrically surrounds the spacer cavity 15, and the volume of the annular buffer cavity 7 is 1 / 4 of the volume of the spacer cavity. The annular buffer cavity 7 extends out of the mold core 9 through the metallographic polishing lubricating coolant inlet pipe 6 and the metallographic polishing lubricating coolant outlet pipe 14 connected to the annular buffer cavity 7. After extending out of the mold core 9, the metallographic polishing lubricating coolant is supplied through the circulation pipe and the metallographic polishing lubricating coolant supply device. Through the circulation pipe and the metallographic polishing lubricating coolant supply device, the metallographic polishing lubricating coolant is always filled in the annular buffer cavity 7 and the spacer cavity 15 during the stretching operation of the beryllium copper wire 1.

[0036] The structural arrangement of the first stretching section 13 and the second stretching section 16 on the compression section enables the second stretching section 16 to perform smoothing and surface repair work on the beryllium copper wire 1 that has been stretched by the first stretching section 13. At the same time, this smoothing and surface repair can also reduce the wire diameter of the wire from the second stretching section 16 by 700nm. In order to ensure the processing accuracy of the beryllium copper wire, the design of the compression section on the corresponding first stretching section 13 should reserve the above-mentioned allowance when designing the stretching die.

[0037] In order to ensure the processing effect of the second stretching section 16, the beryllium copper wire 1 after the first stretching section 13 needs to be cooled before the second stretching section 16 performs secondary processing on the beryllium copper wire 1. However, since the compression section of the first stretching section 13 is set with a large compression angle, the surface temperature of the beryllium copper wire 1 after the stretching treatment of the first stretching section 13 is high, making it difficult to perform continuous secondary processing. The traditional cooling method is to place the beryllium copper wire 1 out of the air for natural cooling, but this requires a large space and although the surface morphology of the cooled beryllium copper wire 1 is stable, there are still certain wire diameter defects. In the embodiments of the present invention, a spacer cavity 15 structure is provided between the first stretching section 13 and the second stretching section 16, so that the wire processed by the first stretching section 13 directly enters a sealed space wrapped by metallographic polishing lubricating coolant when exiting the wire. The space is continuously cooled by the flowing metallographic polishing lubricating coolant, and the cooled beryllium copper wire is exited without contact with air. It then undergoes a small amount of secondary stretching through the second stretching section 16. During the stretching process, the metallographic polishing lubricating coolant is used in conjunction with the stretching friction and surface polishing of the second stretching section 16 to achieve wire diameter and surface repair of the exited wire, so that a beryllium copper wire 1 with better surface performance is obtained at the exit end of the second stretching section 16.

[0038] In another embodiment, in order to improve the surface treatment performance of the second stretching section 16 on the beryllium copper wire 1, titanium can also be plated on the surface of the hard alloy liner of the second stretching section 16, so as to obtain a beryllium copper wire 1 with better surface smoothness at the discharge end of the second stretching section 16 than when the second stretching section 16 is not titanium plated.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that these embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the invention. Furthermore, it should be understood that after reading the technical content of this invention, those skilled in the art can make various alterations, modifications, and / or variations to the invention, and all such equivalent forms also fall within the scope of protection defined by the appended claims.

Claims

1. A high compression angle drawing die for beryllium copper alloy wire, used for drawing operations of beryllium copper alloy wire with a diameter of 0.8~5.0mm, characterized in that, The mold body includes a material handling channel formed inside the mold body. The material handling channel is provided with a feeding area, a first stretching section and a second stretching section in sequence along the wire processing direction. The material handling channel exits from the rear of the second stretching section. The side wall of the feeding area is formed with a lubricating oil supply hole, which is connected to a lubricating oil supply device for stretching via an external pipeline; a pressurized lubricating oil cavity is also formed between the end of the feeding area and the first stretching part. The minimum inner diameter of the stretching cavity of the first stretching part is larger than the minimum inner diameter of the stretching cavity of the second stretching part; the stretching cavity of the first stretching part has a complete and independent inlet section, compression section, holding section and outlet section; the stretching cavity of the second stretching part only includes an inlet section, compression section and outlet section. The compression angle of the compression section of the first tensioning part is greater than 20°; while the compression angle of the compression section of the second tensioning part is 10±2°. The exit chamfer of both the first stretching section and the second stretching section at the exit section is greater than 100°; A spacer cavity is formed between the first stretching part and the second stretching part. A circulation pipeline connected to the spacer cavity is provided on the mold body. The circulation pipeline is externally connected to a metallographic polishing lubricating coolant supply device. Both the first stretching part and the second stretching part are formed on the material processing channel in the form of a cemented carbide liner or a cemented carbide liner; The Rockwell hardness value of the corresponding cemented carbide block or cemented carbide liner on the first stretching part is HRC64~66; the Rockwell hardness value of the corresponding cemented carbide block or cemented carbide liner on the second stretching part is 8~15% smaller than the Rockwell hardness value of the corresponding cemented carbide block or cemented carbide liner on the first stretching part. The surface of the cemented carbide liner or cemented carbide liner in the second stretching section is plated with titanium, and the beryllium copper alloy wire to be processed is repaired in diameter through the second stretching section.

2. The high compression angle drawing die for beryllium copper alloy wire according to claim 1, characterized in that, The mold body includes a detachable mold sleeve and a mold core, and the material processing channel passes through the mold sleeve and the mold core in sequence; the material feeding area is provided on the mold sleeve, and the first stretching part and the second stretching part are provided on the mold core.

3. The high compression angle drawing die for beryllium copper alloy wire according to claim 1, characterized in that, The feeding area is provided with a guide feeding port, which includes a first guide feeding port and a second guide feeding port. Both the first guide feeding port and the second guide feeding port are frustum-shaped structures with an isosceles trapezoidal longitudinal section, and the angle between the hypotenuse of the first guide feeding port and the horizontal plane is greater than the angle between the hypotenuse of the second guide feeding port and the horizontal plane.

4. The high compression angle drawing die for beryllium copper alloy wire according to claim 3, characterized in that, The lubricating oil supply hole is located on the inclined side wall of the second guide inlet.

5. The high compression angle drawing die for beryllium copper alloy wire according to claim 1, characterized in that, The pressurized lubricating oil chamber is an annular cavity surrounding the material processing channel.

6. The high compression angle drawing die for beryllium copper alloy wire according to claim 1, characterized in that, The difference between the minimum inner diameter of the first stretching part and the minimum inner diameter of the second stretching part is 300~1200nm.

7. The high compression angle drawing die for beryllium copper alloy wire according to claim 1, characterized in that, An annular buffer cavity is also formed between the partition cavity and the circulation pipeline, and the volume of the annular buffer cavity is 1 / 4 to 1 / 2 of the volume of the partition cavity.

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