High-efficiency cold extrusion forming process of a fuze body

Abstract

The present application relates to the technical field of precision extrusion processing, in particular to a high-efficiency cold extrusion forming process for a fuse body, comprising the following steps: S1, feeding the cylindrical coil material steel wire to the press by using an automatic feeding device, and cutting the cylindrical coil material into cylindrical sections on the press; S2, automatically feeding the cylindrical sections into the extrusion die of the progressive die for extrusion upsetting; S3, automatically feeding the rod-shaped sections into the extrusion die of the progressive die for multi-stage extrusion, and finally forming the fuse body structure with a cap-shaped head, a middle diameter section and a small diameter section; S4, automatically feeding the fuse body structure into the extrusion tooth die, machining the middle diameter section into a tooth shape in the extrusion tooth die, and finally forming a complete fuse body; and S5, after all the processes are completed, cleaning and quality inspecting the fuse body. The present application solves the technical problems of complex process steps, low previous machining precision, low machining efficiency and high production cost in the prior art when machining small fuse bodies with teeth.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of precision extrusion processing, in particular to a high-efficiency cold extrusion forming process of a fuze body. BACKGROUND

[0002] The fuze is an integrated information system with extremely high reliability, which includes a micro-sized fuze body as shown in the accompanying drawings. Figure 1 The cold upsetting extrusion process is generally used to process and produce the fuze body. During the processing, blanking, extrusion and tooth extrusion processes are required to process the fuze body into the final required shape and size.

[0003] The Chinese patent with the publication number CN109773432A in the prior art provides a multi-station cold extrusion tooth shaft forming process. The metal rod is cut by an automatic sawing machine, and the cut surface is treated by shot blasting. The cut material is heated and extruded to form a blank, and then annealed. The surface of the blank is treated by shot blasting and phosphorus saponification. The tooth part is cold extruded and formed. The spline is cold extruded and formed, and the tooth part is finished. The surface is cut, heat treated and subsequently processed, etc. The tooth shaft with high precision and high strength can be extruded.

[0004] However, the above-mentioned prior art has the following problems when applied to the processing of the fuze body: 1. The processing steps are complex and numerous, and deburring and descaling processes are required during the processing, which reduces the processing efficiency; 2. The previous processing precision is low, and subsequent calibration and finishing are required, which increases the production cost and reduces the processing efficiency. SUMMARY

[0005] The present application provides a high-efficiency cold extrusion forming process of a fuze body, which solves the technical problems of complex process steps, low previous processing precision, low processing efficiency and high production cost in the prior art when processing a small-sized fuze body with teeth.

[0006] The present application provides a high-efficiency cold extrusion forming process of a fuze body, which includes the following steps:

[0007] S1, the cylindrical coil material steel wire is sent to the press by the automatic feeding device, and is cut into a cylindrical section material on the press;

[0008] S2, the cylindrical section material is automatically sent to the extrusion die of the progressive die for extrusion upsetting, and after the extrusion upsetting, a rod-shaped section material with two ends is formed;

[0009] S3, the rod-shaped section material is automatically sent to the extrusion die of the progressive die for multi-stage extrusion, and finally a fuze body section material with a cap-shaped head, a middle diameter section and a small diameter section is formed; a chamfer is arranged between the cap-shaped head and the middle diameter section, and a chamfer is arranged between the middle diameter section and the small diameter section;

[0010] S4, the fuze body structure is automatically sent into an extrusion tooth die, and a middle diameter section is processed into a tooth shape in the extrusion tooth die to form a final fuze body;

[0011] S5, after all the processes are completed, the fuze body is cleaned and quality inspected.

[0012] The beneficial effects of the present application are as follows:

[0013] The present inventors have found in actual production and research that, due to the small size of the fuze body, high machining precision requirements and certain shape machining requirements, the production efficiency of enterprises is greatly affected when the extrusion process is used for production, because the production precision qualified rate cannot be guaranteed due to the large number of processes required and the difficulty in ensuring the production precision.

[0014] 1. After sawing and cutting, the present application processes the section material to be flat at both ends, removes the excess corner material at both ends of the section material, avoids burrs caused by uneven stress on the end face in subsequent processing, and therefore ensures that the process can be continuously produced and the product qualified rate and production precision are high.

[0015] 2. The present application forms sections with different diameters in turn in the extrusion stage, and processes chamfers between different sections, which reduces the stress concentration on the surface of the fuze body, prevents the fuze body from deforming to a large extent during continuous extrusion, and causes the machining precision to decrease. Meanwhile, the multi-stage extrusion method can gradually increase the diameter of the section material, and the mold is not full at the beginning, which is beneficial to demolding and forming.

[0016] 3. The present application adopts a progressive die cold extrusion forming method, and is fed by an automatic feeding device, precisely extruded, and precisely extruded and tooth-shaped, and the entire production process is free of any machining cutting process, and is completely formed by continuous extrusion, the shape and size of the extruded product completely meet the precision and size requirements specified in the finished product drawing, the process technology method has fewer machining process passes, short machining time, high material utilization rate, and the machining efficiency can reach 70 pieces / min, and the machining cost is 0.4 yuan / piece. Compared with the machining efficiency of 15 pieces / min and the machining cost of 2.2 yuan per piece in the prior art, the production cost and production time are greatly reduced. Meanwhile, the product precision of the present application is high, the production batch size diameter precision can be controlled to 0.01 mm, and the batch product quality inspection qualified rate can reach more than 99%.

[0017] Further, the S1 cylindrical coil steel wire model is 20A type steel.

[0018] In the present application, the 20A type steel has stronger cold forging performance than the aluminum parts commonly used in the fuze body, and is not prone to large deformation during production using the extrusion process. At the same time, compared with other small parts manufacturing materials such as 35 type and 40 type steel, the 20A type steel has greater yield strength and tensile strength, and is more suitable for extrusion production of the fuze body.

[0019] Further, the S1 section length is 16-16.2mm, and the diameter is 3.5±0.01mm.

[0020] In the present application, controlling the section length in S1 within a certain range does not cause waste of raw materials, and can save the cutting material and other process steps, thereby improving the processing efficiency. At the same time, controlling the diameter to be slightly smaller than the size of the progressive die facilitates the clamping and moving of the material during processing.

[0021] Further, water cooling is used in S2, S3 and S4, and the water cooling temperature is 40℃.

[0022] In the present application, using water cooling to flush the die and the fuze body can prevent the fuze body from expanding and deforming during processing due to continuous heating, and can prevent the product from shrinking and deforming after processing due to cooling, thereby reducing the production precision of the product.

[0023] Further, in S2, S3 and S4, the acting pressure of the punch is 38-42 Ton.

[0024] In the present application, the acting pressure of the punch determines the forming precision and processing quality of the extrusion forging. If the acting pressure of the punch is too large, the profile processing will be excessive, resulting in burrs or poor precision control. If the acting pressure of the punch is too small, the fuze body will not be processed completely. In the present application, the punch pressure is matched with the diameter of the section material, so that the product pressure during processing is within a reasonable range, thereby ensuring the processing precision.

[0025] Further, the multi-stage extrusion in the process S3 includes primary extrusion, secondary extrusion and tertiary extrusion, the primary extrusion forms a primary stepped section material, the secondary extrusion forms a secondary stepped section material, and the tertiary extrusion forms a fuze body section material.

[0026] In the present application, using multi-stage extrusion can better control the production precision. At the same time, the fuze body in the present application is a large head and thin rod type part, and multi-stage extrusion can prevent cracks from occurring at the edge of the head of the fuze body.

[0027] Further, the first step-shaped section material comprises a first large-diameter section and a first small-diameter section, the first large-diameter section has a diameter of 3.6±0.01mm and a length of 9±0.01mm, and the first small-diameter section has a diameter of 3.55±0.01mm and a length of 7±0.01mm; a first chamfer is arranged between the first large-diameter section and the first small-diameter section, and the first chamfer has an angle of 45°.

[0028] In the present application, the first step-shaped section material is mainly processed to form the first small-diameter section and the first chamfer. The first chamfer can reduce stress concentration of the section material in subsequent processing, and effectively improve the processing precision.

[0029] Further, the second step-shaped section material comprises a second large-diameter section, a second medium-diameter section and a second small-diameter section, the second large-diameter section has a diameter of 3.70±0.01mm and a length of 8±0.01mm, the second medium-diameter section has a diameter of 3.60±0.01mm and a length of 4.80±0.01mm, and the second small-diameter section has a diameter of 2.90±0.01mm and a length of 3.10±0.01mm; a second chamfer is arranged between the second small-diameter section and the second medium-diameter section, and the second chamfer has an angle of 45°.

[0030] In the present application, the second step-shaped section material is mainly processed to form the second small-diameter section and the second chamfer, and the two-level chamfer arrangement ensures the stress condition of the fuze body in the extrusion process, so that the fuze body will not be deformed to a large extent in the processing process, and the processing precision is not poor.

[0031] Further, the fuze body section material comprises a cap-shaped head, a large-diameter section of the fuze body and a small-diameter section of the fuze body, the cap-shaped head has a height of 3.7±0.01mm and a width of 6.4±0.01mm, the large-diameter section of the fuze body has a diameter of 3.65±0.01mm and a length of 4.8±0.01mm, and the small-diameter section of the fuze body has a diameter of 2.95±0.01mm and a length of 2.8±0.01mm.

[0032] In the present application, the fuze body section material is mainly processed to form the cap-shaped head, and the diameters of the large-diameter section of the fuze body and the small-diameter section of the fuze body are further expanded, which lays a foundation for subsequent processing into a fuze body with a size.

[0033] Further, the fuze body in the S4 comprises a cap-shaped head, a tooth-shaped section and a small-diameter section, the tooth-shaped section has a diameter of 3.70±0.01mm and a length of 4.8±0.01mm, and the small-diameter section has a diameter of 3.00±0.01mm and a length of 2.5±0.01mm.

[0034] In the present application, the S4 is mainly used to process the large-diameter section of the fuze body section material into a tooth shape, so that the final structure and size of the fuze body are formed. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 Fig. 1 is a schematic diagram of the processing procedure of the fuze body in the present application;

[0036] Figure 2 Fig. 2 is a schematic diagram of the structure of the male die in the progressive die in the present application;

[0037] Figure 3 Fig. 3 is a sectional view of the male die in the present application; Figure 2

[0038] Figure 4 Fig. 4 is a schematic diagram of the structure of the female die in the progressive die in the present application. DETAILED DESCRIPTION

[0039] The following will be further explained in detail through specific embodiments:

[0040] The marks in the drawings of the present application include: die holder 1, male die fixing plate 2, female die fixing plate 3, male die fixing clamp 4, female die upper cover 5, bar-shaped section material 6, first-stage stepped section material 7, second-stage stepped section material 8, fuze body section material 9, fuze body 10, extrusion male die 21, first-stage extrusion male die 22, second-stage extrusion male die 23, third-stage extrusion male die 24, extrusion tooth male die 25, extrusion female die 31, first-stage extrusion female die 32, second-stage extrusion female die 33, third-stage extrusion female die 34, extrusion tooth female die 35.

[0041] EMBODIMENT

[0042] Referring to the drawings, the present application provides a high-efficiency cold extrusion forming equipment for a fuze body, which comprises a progressive die and a matched press machine. Figures 1-4 As shown in Fig. 2, the progressive die comprises die holder 1, male die fixing plate 2, female die fixing plate 3, male die and female die corresponding to the male die. Male die fixing plate 2 and female die fixing plate 3 are fixedly connected to die holder 1 through bolts. Male die fixing plate 2 is provided with male die fixing clamp 4, one end of which is provided with a thread and can be threadedly connected to male die fixing plate 2. The other end is provided with a clamping hand for clamping and fixing the male die. Female die fixing plate 3 is provided with female die upper cover 5 threadedly connected thereto, and the female die is fixed to female die upper cover 5. Figures 2-3 The male die comprises extrusion male die 21, extrusion male die and extrusion tooth male die 25 arranged in sequence. As shown in Fig. 3, one end of the male die is clamped by male die fixing clamp 4, and the other end extends out of male die fixing clamp 4 and is used for extending into the female die to extrude the section material and process the section material into a corresponding shape.

[0043] Figure 3

[0044] ​​​The extrusion punch 21 extends from one end of the punch fixing clamp 4 and comprises an extrusion punch large diameter section and an extrusion punch taper section; the end of the extrusion punch taper section is a flat surface, and the diameter of the end surface is 3.5 mm. The conical angle of the extrusion punch taper section is 22°. The extrusion punch taper section in this embodiment can upset the two ends of the section material to be flat.

[0045] The extrusion punch comprises a first extrusion punch 22, a second extrusion punch 23 and a third extrusion punch 24. When installed, the first extrusion punch 22 is arranged close to the extrusion punch 21, and the third extrusion punch 24 is arranged close to the extrusion tooth punch 25.

[0046] The first extrusion punch 22 comprises a large diameter straight section, a gradual change section and a small diameter straight section connected in sequence, wherein the large diameter straight section is clamped in the punch fixing clamp 4; the diameter of the small diameter straight section is 3.8 mm, and the length is 25 mm. The second extrusion punch 23 has the same specification as the first extrusion punch 22. In this embodiment, the gradual change section and the small diameter straight section can process the section material into different diameter sections and ensure that the adjacent diameter sections form a chamfer, thereby avoiding stress concentration during the processing of the section material.

[0047] The third extrusion punch 24 extends from one end of the punch fixing clamp 4 and is a cylindrical diameter section with a length of 30 mm and a diameter of 11 mm, and a cap-shaped groove with a height of 3.7 mm and a width of 6.4 mm is arranged on the end surface. The extrusion tooth punch 25 has the same specification as the third extrusion punch 24. In this embodiment, the cap-shaped groove of the third extrusion punch 24 can process the section material into a cap-shaped head; the cap-shaped groove of the extrusion tooth punch 25 can prevent the cap-shaped head processed in the previous process from being upset again. At the same time, the diameters of the third extrusion punch 24 and the extrusion tooth punch 25 are larger than the size of the fuze body, which increases the stress area of the fuze body during processing and ensures the processing quality of the fuze body.

[0048] The punch and the die are arranged one by one and comprise an extrusion die 31, an extrusion die and an extrusion tooth die 35 arranged in sequence. The extrusion die comprises a first extrusion die 32, a second extrusion die 33 and a third extrusion die 34.

[0049] The press machine can adopt a Z41-6 type cold upsetting machine, and since it is prior art, it will not be described in detail here.

[0050] The application also provides a high-efficiency cold extrusion forming process for a fuze body, and the steps are as follows:

[0051] S1, the cylindrical material steel wire is sent to the press machine by an automatic feeding device, and is cut into a cylindrical section material on the press machine;

[0052] Specifically, the 20A type steel material is selected, and the cylindrical material steel wire with a diameter of 3.5 mm is placed on the automatic feeding device. The automatic feeding device delivers the steel wire to the press, and the disc machine in the press cuts the steel wire into cylindrical material with a length of 16.2 mm.

[0053] S2, the cylindrical material is automatically sent to the extrusion die of the progressive die for extrusion upsetting, and after the extrusion upsetting, the rod-shaped material 6 with two ends is formed.

[0054] Specifically, the cylindrical material formed by cutting is sent into the extrusion recess die 31 in the progressive die by the automatic feeding device, and then the extrusion punch 21 is pressed into the extrusion recess die 31 in a positive extrusion manner to upset the material to form the rod-shaped material 6 with two ends. The pressure of the extrusion punch 21 needs to be kept at 40 Ton. After the extrusion is completed, the length of the rod-shaped material 6 is 16 mm, and the diameter is 3.5 mm.

[0055] S3, the rod-shaped material 6 is automatically sent to the extrusion die of the progressive die for multi-stage extrusion, and finally the fuze body material 9 with a cap-shaped head, a middle diameter section and a small diameter section is formed.

[0056] Specifically, the rod-shaped material 6 is first sent into the first-stage extrusion recess die 32, and under the action of the first-stage extrusion punch 22, the rod-shaped material 6 is processed into the first-stage stepped material 7, including a first-stage large diameter section with a diameter of 3.5 mm and a length of 9 mm, and a first-stage small diameter section with a diameter of 3.55 mm and a length of 7 mm. A first-stage chamfer is also extruded between the first-stage large diameter section and the first-stage small diameter section, and the degree of the first-stage chamfer is 45°.

[0057] The first-stage stepped material 7 after processing is sent into the second-stage extrusion recess die 33, and under the action of the second-stage extrusion punch 23, the first-stage stepped material 7 forms the second-stage stepped material 8, including a second-stage large diameter section with a diameter of 3.7 mm and a length of 8 mm, a second-stage middle diameter section with a diameter of 3.6 mm and a length of 4.8 mm, and a second-stage small diameter section with a diameter of 2.9 mm and a length of 3.1 mm. A second-stage chamfer is also extruded between the second-stage small diameter section and the second-stage middle diameter section, and the degree of the second-stage chamfer is 45°.

[0058] The second-stage stepped material 8 after processing is sent into the third-stage extrusion recess die 34, and under the action of the third-stage extrusion punch 24, the second-stage stepped material 8 forms the fuze body material 9, including a cap-shaped head, a fuze body middle diameter section with a diameter of 3.65 mm and a length of 4.8 mm, and a fuze body small diameter section with a diameter of 2.95 mm and a length of 2.8 mm. The height of the cap-shaped head is 3.7 mm, and the width is 6.4 mm.

[0059] S4, the fuze body material 9 is automatically sent into the extrusion tooth die, and the middle diameter section is processed into a tooth shape in the extrusion tooth die to finally form a complete fuze body 10.

[0060] Specifically, the fuze body section material 9 is automatically sent into the extrusion tooth concave die 35, and under the action of the extrusion tooth convex die 25, the medium diameter section of the fuze body section material 9 is processed into a structure with vertical tooth shape. After the processing is completed, the medium diameter section has a diameter of 3.7 mm and a length of 4.8 mm; the small diameter section has a diameter of 3 mm and a length of 2.5 mm.

[0061] S5, after all the processing procedures are completed, the fuze body 10 is cleaned and inspected.

[0062] Specifically, after all the processing procedures are completed, the fuze body 10 is sent to a cleaning pool for flushing. After the cleaning is completed, the fuze body 10 is subjected to machine inspection, and the inspection items include comparison of the sizes of the cap-shaped head, the tooth-shaped diameter section and the small diameter section of the fuze body 10.

[0063] According to the fuze body produced in the embodiment, the qualified rate in the inspection can reach more than 99%. Meanwhile, the size precision of the qualified product can be controlled to be 0.01 mm, which meets the production standard of the fuze body. In the production cost accounting, the production cost of each fuze body is only 0.4 yuan per piece, which is far lower than the single piece cost of the fuze body in the prior art.

[0064] In addition, the inventors of the present application also try to change the above production conditions for experiments, for example, the extrusion die is not arranged in the progressive die to perform two-end upsetting of the cylindrical section material for continuous production, and the production result shows that the qualified rate of the final fuze body is about 80%, and the main problem is that the diameter size of the fuze body is unqualified, and the surface of the product is relatively rough. In addition, the inventors do not perform chamfering processing on the product in the steps S2 and S3, and it is found in the continuous production that the size change of the final product is relatively large in the continuous extrusion, and the diameter of the tooth-shaped diameter section of part of the products even rises to about 3.8 mm. The qualified rate of the final product is only about 50%. Furthermore, the inventors find that if the initial diameter of the section material is reduced, although the die pressure can be reduced to reduce the operation cost of the press, the product produced finally needs to be deformed to a large extent, which leads to a sharp decrease in the processing precision of the product, and the product qualified rate is only about 30%.

[0065] The above is only an embodiment of the present application, and the present application is not limited to the field related to the embodiment. The common knowledge of the specific structure and characteristics in the scheme is not described in detail. It should be noted that, for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should also be regarded as the protection scope of the present application. The protection scope of the present application should be subject to the content of the claims, and the specific implementation mode and the like in the description can be used to explain the content of the claims.

Claims

1. A highly efficient cold extrusion molding process for a fuse body, characterized in that, The process includes the following steps: S1. The cylindrical coiled steel wire is fed to the press using an automatic feeding device and cut into cylindrical sections on the press. S2. The cylindrical material segment is automatically fed into the extrusion die of the progressive die for extrusion and upsetting, and after extrusion and upsetting, it forms a rod-shaped material segment with neat ends. S3. The rod-shaped material is automatically fed into the extrusion die of the progressive die for multi-stage extrusion, finally forming a fuse body structure with a cap-shaped head, a medium diameter section and a small diameter section. S4. The fuse body structure is automatically fed into the extrusion die of the progressive die, where the middle diameter section is machined into a tooth shape, ultimately forming a complete fuse body. The progressive die includes a die base, a punch fixing plate, a die fixing plate, a punch, and a die corresponding to the punch. The punch includes a pressing punch, a forming punch, and a toothed punch arranged in sequence. The pressing punch includes a large diameter section and a tapered section. The end of the tapered section is flat, and the diameter of the end face is 3.5 mm. The cone angle of the tapered section is 22°. S5. After all processes are completed, the fuse body is cleaned and inspected.

2. The efficient cold extrusion molding process for a fuse body according to claim 1, characterized in that: The cylindrical coiled steel wire in S1 is of type 20A steel.

3. The efficient cold extrusion molding process for a fuse body according to claim 2, characterized in that: The material-saving section in S1 has a length of 16-16.2 mm and a diameter of 3.5 ± 0.01 mm.

4. The efficient cold extrusion molding process for a fuse body according to claim 1, characterized in that: Water-cooled rinsing is used in S2, S3 and S4, with a water-cooling temperature of 35-45℃.

5. The efficient cold extrusion molding process for a fuse body according to claim 1, characterized in that: In S2, S3 and S4, the pressure applied by the punch is 38-42 Ton.

6. The efficient cold extrusion molding process for a fuse body according to claim 1, characterized in that: The multi-stage extrusion process S3 includes primary extrusion, secondary extrusion and tertiary extrusion. Primary extrusion forms primary stepped material segments; secondary extrusion forms secondary stepped material segments; and tertiary extrusion forms fuse material segments.

7. The efficient cold extrusion molding process for a fuse body according to claim 6, characterized in that: The first-stage stepped material segment includes a first-stage large-diameter section and a first-stage small-diameter section. The diameter of the first-stage large-diameter section is 3.6±0.01mm and the length is 9±0.01mm. The diameter of the first-stage small-diameter section is 3.55±0.01mm and the length is 7±0.01mm. A first-stage chamfer with an angle of 45° is provided between the first-stage large-diameter section and the first-stage small-diameter section.

8. The efficient cold extrusion molding process for a fuse body according to claim 6, characterized in that: The secondary stepped material segment includes a secondary large-diameter section, a secondary medium-diameter section, and a secondary small-diameter section. The diameter of the secondary large-diameter section is 3.70±0.01 mm, and the length is 8±0.01 mm; the diameter of the secondary medium-diameter section is 3.60±0.01 mm, and the length is 4.80±0.01 mm; the diameter of the secondary small-diameter section is 2.90±0.01 mm, and the length is 3.10±0.01 mm. The secondary small-diameter section and the secondary medium-diameter section form a secondary chamfer with an angle of 45°.

9. The efficient cold extrusion molding process for a fuse body according to claim 6, characterized in that: The fuse body comprises a cap-shaped head, a large-diameter section, and a small-diameter section. The cap-shaped head has a height of 3.7±0.01 mm and a width of 6.4±0.01 mm. The large-diameter section has a diameter of 3.65±0.01 mm and a length of 4.8±0.01 mm. The small-diameter section has a diameter of 2.95±0.01 mm and a length of 2.8±0.01 mm.

10. The efficient cold extrusion molding process for a fuse body according to claim 6, characterized in that: The fuse body in S4 includes a cap-shaped head, a toothed diameter section, and a small diameter section, wherein the diameter of the toothed diameter section is 3.70±0.01mm and the length is 4.8±0.01mm; the diameter of the small diameter section is 3.00±0.01mm and the length is 2.5±0.01mm.

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