Rear through mechanism of cold heading forming machine

Abstract

A rear through mechanism of a cold heading forming machine belongs to the technical field of cold heading devices and comprises a main frame capable of being mounted on the cold heading forming machine, a motor is fixedly arranged on the upper wall of the main frame, a rotating shaft is fixedly arranged at the output shaft end of the motor, and the upper end of the rotating shaft movably penetrates through the upper wall of the main frame. The lower end of the rotating shaft is movably arranged on the lower wall of the main frame through a bearing, a reciprocating motion assembly is movably arranged in the main frame and arranged on the rotating shaft, an ejector pin is fixedly arranged at the output end of the reciprocating motion assembly, and the other end of the ejector pin movably penetrates through the side wall of the main frame. And an auxiliary discharging assembly is arranged at the other end of the ejector pin, so that non-standard products sleeving the ejector pin can be separated, the stroke of the ejector pin is increased, and the ejection efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of cold heading devices, in particular to a back-through mechanism of a cold heading forming machine.

[0002] Background technology Cold heading is a processing method that applies impact force to metal without heating to make the metal form in a predetermined mold. It is also called cold heading stamping. The process of cold heading is to feed the disc round bar through the roller transmission, and then carry out multiple processes such as feeding, cutting, pressing balls, pressing angles, punching, etc. at one time. Cold heading processing has the characteristics of high material utilization, high production efficiency, good mechanical properties, and low investment in one machine for multiple uses. Therefore, cold heading products are becoming more and more diversified.

[0003] For some products with perforations after processing, such as gaskets, nuts, sleeves, etc., these products are ejected by the back-through mechanism after cold heading. Because the products have perforations, or the product processing is unqualified, and the holes are not standardized, the products will be sleeved on the ejector pin, and when the ejector pin is reset, it will carry the products back into the die and cannot be completely separated, which will cause the cold heading machine to be unable to feed normally and affect the production of the cold heading machine; for some extra-long products, such as screws, rivets, etc., these products need to dive the back-through mechanism to a sufficient depth during cold heading to avoid affecting the product molding, resulting in an increase in the ejection stroke of the back-through mechanism and a decrease in the ejection efficiency. Therefore, tedious and complicated pre-debugging is required, which brings inconvenience to the producer. Summary of the invention

[0004] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a back-through mechanism of a cold heading forming machine, which at least partially solves the problems raised in the above background technology.

[0005] The technical solution adopted by the present invention is as follows: a rear-through mechanism of a cold heading machine, comprising a main frame that can be installed on the cold heading machine, a motor is fixedly provided on the upper wall of the main frame, and a rotating shaft is fixedly provided on the output shaft end of the motor, the upper end of the rotating shaft movably penetrates the upper wall of the main frame, the lower end of the rotating shaft is movably provided on the lower wall of the main frame through a bearing, a reciprocating motion component is movably provided in the main frame, the reciprocating motion component is provided on the rotating shaft, a pin is fixedly provided on the output end of the reciprocating motion component, the other end of the pin movably penetrates the side wall of the main frame, and an auxiliary blanking component is provided on the other end of the pin.

[0006] Further, the auxiliary blanking assembly includes a front extension plate, a front fixing plate, a rear fixing plate, a guide rod, a sliding plate and a top sheath. The front extension plate extends and is provided on the side wall of the main frame, and the front extension plate is provided above the ejector pin. The front fixing plate is provided on the lower wall at the end of the front extension plate. The rear fixing plate is provided on the side wall of the main frame. One end of the guide rod is fixedly provided on the front fixing plate, and the other end of the guide rod is fixedly provided on the rear fixing plate. The sliding plate is movably provided on the guide rod. The top sheath is fixedly provided at the lower end of the sliding plate. The ejector pin movably penetrates through the top sheath. A spring is sleeved on the guide rod. One end of the spring abuts against the rear fixing plate, and the other end of the spring abuts against the sliding plate. Line holes are symmetrically provided on the side wall of the top sheath. Sliders are symmetrically provided on the side wall of the ejector pin. The size of the sliders is matched with that of the line holes.

[0007] Further, the sliders are arranged close to the end of the ejector pin, and the distance between the sliders and the end of the ejector pin is less than the length of the line holes.

[0008] In a further embodiment, a top plate is provided at the end of the top sheath, and the top plate is arranged in a C shape.

[0009] Further, the reciprocating motion assembly includes a positioning plate, a connecting rod, a first gear, a second gear, a driving shaft and a driving frame. There are two groups of positioning plates. Two positioning rotation holes are provided on each group of positioning plates. The connecting rod is fixedly connected and arranged between the two groups of positioning plates. Circular bumps are provided on the upper and lower walls of the first gear and the second gear. The size of the circular bumps is matched with that of the positioning rotation holes. The first gear is arranged between the two groups of positioning plates through the cooperation of the circular bump and one group of positioning rotation holes. The second gear is arranged between the two groups of positioning plates through the cooperation of the circular bump and the other group of positioning rotation holes. And the second gear is meshed with the first gear. The first gear is eccentrically fixed on a rotating shaft. The driving shaft is eccentrically fixedly penetrated through the second gear, and the driving shaft and the rotating shaft are arranged to be close to each other. The driving frame is arranged in a U shape in the main frame. The end of the driving frame is movably arranged on the driving shaft. The ejector pin is fixedly arranged on the driving frame.

[0010] Further, the first gear and the second gear have the same number of teeth, and the working axes of the first gear and the second gear are on the same straight line.

[0011] In a further embodiment, a guide hole is provided on the side wall of the main frame. The guide hole, the rotating shaft and the driving shaft are arranged on the same straight line. The other end of the ejector pin movably penetrates through the guide hole.

[0012] In a further embodiment, a wear-resistant tube is provided in the guide hole. The other end of the ejector pin movably penetrates through the wear-resistant tube. The rear fixing plate is arranged at the upper end of the wear-resistant tube.

[0013] In a further embodiment, a locking pin is provided on one side wall of the main frame, and the locking pin is arranged on the other side away from the guide hole.

[0014] In a further embodiment, a protective shell is provided on the upper wall of the main frame, and the motor is arranged inside the protective shell.

[0015] The beneficial effects achieved by the present invention using the above structure are as follows: The ejector sheath in the auxiliary unloading component can cooperate with the ejector pin. The reciprocating motion component drives the ejector pin to eject the product in the die. The ejector sheath ejects the product stuck at the end of the ejector pin. At the same time, the ejector pin can slide and retract in the ejector sheath to eject the product stuck on the ejector sheath. The movement stroke of the first gear and the second gear in the reciprocating motion assembly is greater than the traditional crank slider stroke, so it can drive the ejector to increase the stroke to be suitable for the rear ejection of some extra-long products. At the same time, the speed of the crank slider decreases faster than the first gear and the second gear when rushing forward, that is, the first gear and the second gear obtain a greater stroke speed with the same length of crank, thereby improving the ejection efficiency of the ejector. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the rear-pass mechanism of the cold heading forming machine proposed in an embodiment of the present invention; Figure 2 A front view of a rear-pass mechanism of a cold heading forming machine according to an embodiment of the present invention; Figure 3 It is a right side view of the rear-pass mechanism of the cold heading forming machine proposed in the embodiment of the present invention; Figure 4 A schematic diagram of the overall structure of a reciprocating motion assembly proposed in an embodiment of the present invention; Figure 5 A schematic diagram of a partial structure of a reciprocating motion component proposed in an embodiment of the present invention; Figure 6 A reference diagram of a first use state of the auxiliary blanking assembly provided in an embodiment of the present invention; Figure 7 This is a reference diagram of the second usage state of the auxiliary blanking assembly proposed in an embodiment of the present invention.

[0017] Among them, 1. main frame, 2. motor, 3. rotating shaft, 4. reciprocating motion component, 5. ejector pin, 6. auxiliary unloading component, 7. front extension plate, 8. front fixed plate, 9. rear fixed plate, 10. guide rod, 11. sliding plate, 12. ejector sheath, 13. spring, 14. wire hole, 15. slider, 16. ejector plate, 17. positioning plate, 18. connecting rod, 19. first gear, 20. second gear, 21. driving shaft, 22. driving frame, 23. positioning rotating hole, 24. circular protrusion, 25. guide hole, 26. wear-resistant tube, 27. locking pin, 28. protective shell.

[0018] The accompanying drawings are used to provide further understanding of the embodiments and constitute a part of the specification. They are used for explanation together with the embodiments of the present invention and do not constitute a limitation of the embodiments. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection.

[0020] In the description of the embodiments, it should be understood that terms such as "up", "down", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the embodiments.

[0021] Cold heading is a processing method that applies impact force to metal without heating to make the metal form in a predetermined mold. It is also called cold heading stamping. The process of cold heading is to feed the disc round bar through the roller transmission, and then carry out multiple processes such as feeding, cutting, pressing, corner pressing, punching, etc. at one time.

[0022] For some products with perforations after processing, such as gaskets, nuts, sleeves, etc., these products are ejected by the back-through mechanism after cold heading. Because the products have perforations, or the product processing is unqualified, and the holes are not standardized, the products will be sleeved on the ejector pin, and when the ejector pin is reset, it will carry the products back into the die and cannot be completely separated, which will cause the cold heading machine to be unable to feed normally and affect the production of the cold heading machine; for some extra-long products, such as screws, rivets, etc., these products need to dive the back-through mechanism to a sufficient depth during cold heading to avoid affecting the product molding, resulting in an increase in the ejection stroke of the back-through mechanism and a decrease in the ejection efficiency. Therefore, tedious and complicated pre-debugging is required, which brings inconvenience to the producer.

[0023] After recognizing the above problems, the present application proposes and discloses a back-through mechanism of a cold heading forming machine, which can make the irregular products sleeved on the ejector pin detach, increase the ejector pin stroke, and improve the ejection efficiency.

[0024] Referring to the accompanying drawings, Figure 1 , Figure 2 and Figure 3 As shown, the embodiment of the present disclosure provides a rear-through mechanism of a cold heading machine, including a main frame 1 that can be installed on the cold heading machine, a motor 2 is fixedly provided on the upper wall of the main frame 1, and a rotating shaft 3 is fixedly provided on the output shaft end of the motor 2, the upper end of the rotating shaft 3 movably passes through the upper wall of the main frame 1, and the lower end of the rotating shaft 3 is movably provided on the lower wall of the main frame 1 through a bearing, a reciprocating motion component 4 is movably provided in the main frame 1, the reciprocating motion component 4 is provided on the rotating shaft 3, an ejector 5 is fixedly provided at the output end of the reciprocating motion component 4, the other end of the ejector 5 movably passes through the side wall of the main frame 1, and an auxiliary blanking component 6 is provided on the other end of the ejector 5.

[0025] In this embodiment, the output shaft end of the motor 2 drives the rotating shaft 3 to rotate, the rotating shaft 3 drives the reciprocating motion component 4 to reciprocate, and the reciprocating motion component 4 drives the auxiliary unloading component 6 through the ejector pin 5 to complete the unloading, wherein the auxiliary unloading component 6 can make the irregular products sleeved on the ejector pin 5 detach, and the reciprocating motion component 4 can increase the ejection stroke of the rear-through mechanism and improve the ejection efficiency.

[0026] like Figure 1 , Figure 2 , Figure 3 , Figure 6 and Figure 7As shown, the auxiliary blanking component 6 includes a front extension plate 7, a front fixed plate 8, a rear fixed plate 9, a guide rod 10, a sliding plate 11 and an ejector sheath 12. The front extension plate 7 is extended to the side wall of the main frame 1, and the front extension plate 7 is arranged above the ejector pin 5. The front fixed plate 8 is arranged on the lower wall of the end of the front extension plate 7, and the rear fixed plate 9 is arranged on the side wall of the main frame 1. One end of the guide rod 10 is fixed on the front fixed plate 8, and the other end of the guide rod 10 is fixed on the rear fixed plate 9. The sliding plate 11 is movably arranged on the guide rod 10. The ejector sheath 12 is fixed at the lower end of the sliding plate 11. The ejector pin 5 is movably penetrated through the ejector sheath 12. A spring 13 is sleeved on the guide rod 10, one end of the spring 13 is arranged against the rear fixed plate 9, and the other end of the spring 13 is arranged against the sliding plate 11. The side wall of the ejector sheath 12 is symmetrically provided with wire holes 14, and the side wall of the ejector pin 5 is symmetrically provided with sliders 15, and the size of the sliders 15 is matched with the wire holes 14.

[0027] In this embodiment, when the reciprocating motion component 4 drives the ejector 5 to slide and eject in the ejector sheath 12, the ejector 5 drives the sliders 15 on both sides to slide to the end of the wire hole 14. During the sliding process, due to the loss of the limiting effect of the sliders 15, the spring 13 recovers from the contracted state and pushes the sliding plate 11 to the front fixed plate 8, thereby realizing the positioning of the ejector sheath 12. When the ejector 5 protrudes out of the ejector sheath 12 for a distance, the slider 15 slides to the end of the wire hole 14. At this time, the end of the ejector 5 extends out of the ejector sheath 12 to eject the product in the die.

[0028] When the reciprocating assembly 4 drives the ejector pin 5 to slide and retract in the ejector sheath 12, the ejector pin 5 drives the sliders 15 on both sides to slide close to the head end of the wire hole 14. During the sliding process, due to the supporting force of the spring 13, the position of the ejector sheath 12 remains unchanged, and the end of the ejector pin 5 slides into the ejector sheath 12, and the ejector sheath 12 ejects the product stuck at the end of the ejector pin 5. As the ejector pin 5 continues to slide deeper into the main frame 1, the sliders 15 on both sides of the ejector pin 5 slide against the head end of the wire hole 14, and then drive the ejector sheath 12 and the sliding plate 11 to move toward the rear fixed plate 9 through the wire hole 14. The ejector sheath 12 moves away from the die, and the sliding plate 11 compresses the spring 13 to contract.

[0029] like Figure 6 and Figure 7 As shown, the slider 15 is disposed close to the end of the ejector pin 5 , and the distance between the slider 15 and the end of the ejector pin 5 is smaller than the length of the wire hole 14 .

[0030] In this embodiment, when the distance between the slider 15 and the end of the ejector pin 5 is less than the length of the wire hole 14, the end of the ejector pin 5 can be completely retracted into the ejector sheath 12. When the positions of the ejector sheath 12 and the end of the ejector pin 5 deviate, the ejector sheath 12 can eject the product at the end of the ejector pin 5 out of the die.

[0031] like Figure 6 and Figure 7As shown, a top plate 16 is provided at the end of the top sheath 12, and the top plate 16 is arranged in a C shape.

[0032] In this embodiment, the top plate 16 can directly push against the die product. The top plate 16 has high strength and high toughness, and can resist the impact force generated when pushing the product, preventing the top sheath 12 from cracking. The material of the top plate 16 has good anti-aging performance and stability to ensure that it can effectively play its role within the service life of the top sheath 12.

[0033] As Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, the reciprocating motion assembly 4 includes a positioning plate 17, a connecting rod 18, a first gear 19, a second gear 20, a drive shaft 21 and a drive frame 22. There are two groups of positioning plates 17, and two groups of positioning rotation holes 23 are provided on each group of positioning plates 17. The connecting rod 18 is fixedly connected between the two groups of positioning plates 17. Circular bumps 24 are provided on the upper and lower walls of the first gear 19 and the second gear 20, and the circular bumps 24 are matched in size with the positioning rotation holes 23. The first gear 19 is arranged between the two groups of positioning plates 17 through the cooperation of the circular bump 24 and one group of positioning rotation holes 23, and the second gear 20 is arranged between the two groups of positioning plates 17 through the cooperation of the circular bump 24 and the other group of positioning rotation holes 23, and the second gear 20 is meshed with the first gear 19. The first gear 19 is eccentrically fixed on the rotating shaft 3, the drive shaft 21 is eccentrically fixedly penetrated through the second gear 20, and the drive shaft 21 and the rotating shaft 3 are arranged to be close to each other. The drive frame 22 is arranged in a U shape in the main frame 1, the end of the drive frame 22 is movably arranged on the drive shaft 21, and the ejector pin 5 is fixedly arranged on the drive frame 22.

[0034] As Figure 4 and Figure 5 As shown, the first gear 19 and the second gear 20 have the same number of teeth, and the working axes of the first gear 19 and the second gear 20 are on the same straight line.

[0035] In this embodiment, the output shaft end of the motor 2 drives the first gear 19 to rotate in the positioning rotation holes 23 between the two groups of positioning plates 17 through the rotating shaft 3. The first gear 19 meshes with and drives the second gear 20 to rotate. When the rotating shaft 3 and the drive shaft 21 are close to each other, the eccentric distance between the first gear 19 and the second gear 20 is the closest. When the rotating shaft 3 and the drive shaft 21 are far from each other, the eccentric distance between the first gear 19 and the second gear 20 is the farthest.

[0036] Compared with the traditional crank slider 15 mechanism, when the eccentric distances of the crank and the gear of the crank slider 15 mechanism are the same and the length of the connecting rod is the same as the sum of the lengths of the first gear 19 and the second gear 20, the movement stroke of the first gear 19 and the second gear 20 is greater than the stroke of the crank slider 15, thereby driving the ejector pin 5 to increase the stroke to be suitable for the rear ejection of some extra-long products. At the same time, the speed of the crank slider 15 decreases faster than the first gear 19 and the second gear 20 when rushing forward, that is, the first gear 19 and the second gear 20 obtain a greater stroke speed with a crank of the same length, thereby improving the ejection efficiency of the ejector pin 5.

[0037] like Figure 1 and Figure 2 As shown, a guide hole 25 is provided on the side wall of the main frame 1 , and the guide hole 25 is arranged on the same straight line as the rotating shaft 3 and the driving shaft 21 , and the other end of the ejector pin 5 is movably arranged to pass through the guide hole 25 .

[0038] In this embodiment, during the movement of the second gear 20 driven by the meshing of the first gear 19, vibration may occur due to the large change in the center of mass position and the large mass of the gear. The guide hole 25 may limit the position of the ejector pin 5 to prevent the ejector pin 5 from vibrating greatly and affecting the ejection efficiency of the product.

[0039] like Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown, a wear-resistant tube 26 is provided in the guide hole 25 , the other end of the ejector pin 5 movably penetrates the wear-resistant tube 26 , and the rear fixing plate 9 is provided at the upper end of the wear-resistant tube 26 .

[0040] In this embodiment, during the movement of the second gear 20 driven by the meshing of the first gear 19, vibration will occur due to the large change in the center of mass position and the large mass of the gears. The wear-resistant tube 26 can effectively overcome the wear on the guide hole 25 caused by the vibration of the ejector pin 5, thereby increasing the service life of the product.

[0041] like Figure 1 and Figure 2 As shown, a locking pin 27 is disposed on one side wall of the main frame 1 , and the locking pin 27 is disposed on the other side away from the guide hole 25 .

[0042] In this embodiment, the main frame 1 can be installed and fixed in the reserved installation groove of the rear through mechanism of the cold heading machine by means of the locking pin 27 .

[0043] like Figure 1 , Figure 2 and Figure 3 As shown, a protective shell 28 is provided on the upper wall of the main frame 1 , and the motor 2 is arranged inside the protective shell 28 . The protective shell 28 can effectively protect the motor 2 .

[0044] During specific use, the output shaft end of the motor 2 drives the first gear 19 to rotate in the positioning rotating hole 23 between the two groups of positioning plates 17 through the rotating shaft 3, and the first gear 19 engages to drive the second gear 20 to rotate. When the rotating shaft 3 and the driving shaft 21 move away from each other, the eccentric distance between the first gear 19 and the second gear 20 is the farthest. The driving shaft 21 drives the ejector 5 to slide in the ejection sheath 12 through the driving frame 22 to perform an ejection action. The sliders 15 on both sides of the ejector 5 slide to the end of the wire hole 14. During the sliding process, due to the loss of the limiting effect of the slider 15, the spring 13 stretches outward from the contracted state and pushes the sliding plate 11 to the front fixed plate 8, thereby fixing the position of the ejector sheath 12. When the ejector 5 protrudes out of the ejector sheath 12 for a distance, the slider 15 slides to the end of the wire hole 14. At this time, the end of the ejector 5 extends out of the ejector sheath 12 to eject the product in the die.

[0045] When the rotating shaft 3 and the driving shaft 21 are close to each other, the eccentric distance between the first gear 19 and the second gear 20 is the shortest, and the driving shaft 21 drives the ejector 5 to slide and retract in the ejector sheath 12 through the driving frame 22, and the ejector 5 drives the sliders 15 on both sides to slide close to the head end of the wire hole 14. During the sliding process, due to the supporting force of the spring 13, the position of the ejector sheath 12 remains unchanged, and the end of the ejector 5 slides into the ejector sheath 12, and the ejector sheath 12 ejects the product stuck at the end of the ejector 5 through the ejector plate 16. As the ejector 5 continues to slide deeper into the main frame 1, the sliders 15 on both sides of the ejector 5 slide against the head end of the wire hole 14, and then drive the ejector sheath 12 and the sliding plate 11 to move toward the rear fixed plate 9 through the wire hole 14, and the ejector sheath 12 moves away from the die, and the sliding plate 11 compresses the spring 13 to contract.

[0046] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0047] Although embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations may be made to the embodiments without departing from the principles and spirit thereof, and the scope of the embodiments is defined by the appended claims and their equivalents.

[0048] The above description of the implementation mode is not restrictive, and the drawings show only one of the implementation modes, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the scope of protection.

Claims

1. A back-through mechanism of a cold heading machine, characterized in that: The invention comprises a main frame (1) which can be installed on a cold heading forming machine, wherein a motor (2) is fixedly provided on the upper wall of the main frame (1), and a rotating shaft (3) is fixedly provided on the output shaft end of the motor (2), the upper end of the rotating shaft (3) is movably arranged through the upper wall of the main frame (1), and the lower end of the rotating shaft (3) is movably arranged on the lower wall of the main frame (1) through a bearing, a reciprocating motion component (4) is movably provided in the main frame (1), the reciprocating motion component (4) is arranged on the rotating shaft (3), an ejector pin (5) is fixedly provided on the output end of the reciprocating motion component (4), the other end of the ejector pin (5) is movably arranged through the side wall of the main frame (1), and an auxiliary blanking component (6) is provided on the other end of the ejector pin (5). The auxiliary unloading assembly (6) comprises a front extension plate (7), a front fixed plate (8), a rear fixed plate (9), a guide rod (10), a sliding plate (11) and an ejector sheath (12), wherein the front extension plate (7) is extended on the side wall of the main frame (1), and the front extension plate (7) is arranged above the ejector pin (5), the front fixed plate (8) is arranged on the lower wall of the end of the front extension plate (7), the rear fixed plate (9) is arranged on the side wall of the main frame (1), one end of the guide rod (10) is fixed on the front fixed plate (8), and the other end of the guide rod (10) is fixed on the rear fixed plate (9), and the The sliding plate (11) is movably arranged on the guide rod (10), the ejector sheath (12) is fixedly arranged at the lower end of the sliding plate (11), the ejector pin (5) is movably arranged to penetrate the ejector sheath (12), a spring (13) is sleeved on the guide rod (10), one end of the spring (13) is arranged against the rear fixed plate (9), and the other end of the spring (13) is arranged against the sliding plate (11), the side wall of the ejector sheath (12) is symmetrically provided with wire holes (14), and the side wall of the ejector pin (5) is symmetrically provided with sliders (15), and the size of the sliders (15) is matched with the wire holes (14).

2. The back-pass mechanism of the cold heading machine according to claim 1, characterized in that: The slider (15) is arranged close to the end of the ejector pin (5), and the distance between the slider (15) and the end of the ejector pin (5) is less than the length of the wire hole (14).

3. The back-pass mechanism of the cold heading machine according to claim 1, characterized in that: A top plate (16) is provided at the end of the ejecting sheath (12), and the top plate (16) is arranged in a C shape.

4. The back-pass mechanism of the cold heading machine according to claim 1, characterized in that: The reciprocating motion assembly (4) includes a positioning plate (17), a connecting rod (18), a first gear (19), a second gear (20), a driving shaft (21) and a driving frame (22). There are two groups of the positioning plates (17), and two positioning rotation holes (23) are provided on each group of the positioning plates (17). The connecting rod (18) is fixedly connected and arranged between the two groups of positioning plates (17). Circular bumps (24) are provided on the upper and lower walls of the first gear (19) and the second gear (20). The circular bumps (24) are arranged in a matching size with the positioning rotation holes (23). The first gear (19) is arranged between the two groups of positioning plates (17) through the cooperation of the circular bump (24) and one group of the positioning rotation holes (23). The second gear (20) is arranged between the two groups of positioning plates (17) through the cooperation of the circular bump (24) and the other group of the positioning rotation holes (23), and the second gear (20) is meshed with the first gear (19). The first gear (19) is eccentrically fixed on the rotating shaft (3). The driving shaft (21) is eccentrically fixed and penetrates through the second gear (20), and the driving shaft (21) and the rotating shaft (3) are arranged to be close to each other. The driving frame (22) is arranged in a U shape in the main frame (1). The end of the driving frame (22) is movably arranged on the driving shaft (21). The thimble (5) is fixedly arranged on the driving frame (22).

5. The back-pass mechanism of the cold heading machine according to claim 4, characterized in that: The number of teeth of the first gear (19) and the second gear (20) is the same, and the working axes of the first gear (19) and the second gear (20) are on the same straight line.

6. The back-pass mechanism of the cold heading machine according to claim 5, characterized in that: A guiding hole (25) is provided on the side wall of the main frame (1). The guiding hole (25) and the rotating shaft (3), the driving shaft (21) are arranged on the same straight line. The other end of the thimble (5) movably penetrates through the guiding hole (25).

7. The back-pass mechanism of the cold heading machine according to claim 6, characterized in that: A wear-resistant tube (26) is arranged in the guiding hole (25). The other end of the thimble (5) movably penetrates through the wear-resistant tube (26). The rear fixing plate (9) is arranged at the upper end of the wear-resistant tube (26).

8. The back-pass mechanism of the cold heading machine according to claim 7, characterized in that: A locking pin (27) is provided on one side wall of the main frame (1). The locking pin (27) is arranged on the other side away from the guiding hole (25).

9. The back-pass mechanism of the cold heading machine according to claim 1, characterized in that: A protective shell (28) is provided on the upper wall of the main frame (1). The motor (2) is arranged inside the protective shell (28).

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