A cold heading device for workpieces

Abstract

The present invention discloses a cold heading device for a workpiece, wherein the workpiece includes a rod body and a circular flange extending from one end of the rod body, the diameter of the circular flange is greater than the length of the rod body, the cold heading device includes a first die for forming a straight section of a preset blank, a second die for forming a circular flange at one end of the straight section and a rod body at the other end, a third die for extruding the circular flange into a toothed flange and separating the toothed flange from its outer edge waste, a clamping jaw assembly for overmolding the workpiece is provided between the second and third dies, the clamping jaw assembly includes at least two oppositely arranged clamping jaws, which include a clamping portion that fits and matches the side surface of the circular flange and a supporting portion that fits the table surface of the circular flange away from the rod body. The cold heading device for the workpiece of the present invention can stabilize the overmolded workpiece, avoid burrs on the cutting material, ensure product quality, and improve processing efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of cold heading, in particular to a cold heading device for workpieces. Background Art

[0002] Cold heading is one of the few non-cutting metalworking processes. It utilizes the plastic deformation of metal under external forces, redistributing and shifting the metal's volume through a die, to form the desired part or blank. Cold heading is best suited for producing standard fasteners such as bolts, screws, nuts, and rivets.

[0003] In the existing cold heading process, the coordination between multiple-station molds is generally required to finally form the product. This involves the transportation of the workpieces between the various stations, and transportation generally requires the use of over-die clamps. However, when using over-die clamps, they are generally clamped to the rod of the part. However, for some workpieces with large flanges and short rods, clamping the rod is difficult to achieve, and automated production cannot be achieved. It is necessary to use a punch press to punch out the flange separately. Although the product quality rate is guaranteed, the production cycle is long. Therefore, it is proposed to use cold forging to form the workpiece. However, this operation method will make the part to be formed less full and have more burrs, which increases the product defect rate. Therefore, the processing of large flange and short rod parts is an issue that still needs to be explored. Summary of the Invention

[0004] In order to overcome the defects in the prior art, the main purpose of the present invention is to provide a cold heading device for parts. The provided cold heading device for parts can stabilize the over-die processed parts, avoid burrs on the cutting material, ensure the product quality rate, and improve processing efficiency.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] The present invention provides a cold heading device for a workpiece, wherein the workpiece includes a rod and a circular flange extending from one end of the rod, the diameter of the circular flange being greater than the length of the rod, and the cold heading device includes:

[0007] A first die for forming a straight section of a predetermined blank;

[0008] a second mold for forming the circular flange at one end of the straight section and forming the rod body at the other end of the straight section;

[0009] a third die for extruding the circular flange into a toothed flange and separating the toothed flange from waste material at its outer edge;

[0010] Among them, a clamping jaw assembly for over-molding the workpiece is provided between the second mold and the third mold, and the clamping jaw assembly includes at least two clamping jaws arranged opposite to each other, and the clamping jaw includes a clamping portion that fits with the side of the circular flange, and a supporting portion that fits with the table surface of the circular flange facing away from the rod body. A clamping space adapted to the circular flange is formed between the opposing clamping portions, and the opposing supporting portions jointly form a stop platform adapted to the table surface.

[0011] As a further description of the above technical solution, when the workpiece in the second mold is in a demolding state, the clamping space is arranged opposite to the main mold cavity of the second mold.

[0012] As a further description of the above technical solution, the stop platform has an avoidance portion, and the avoidance portion is formed by the two supporting portions being recessed inward.

[0013] As a further description of the above technical solution, the clamping portion is an arc-shaped surface.

[0014] As a further description of the above technical solution, the clamp also includes a groove portion for accommodating the rod body, and an accommodating space for accommodating the rod body is formed between the relative groove portions. The diameter of the accommodating space is larger than the outer diameter of the rod body and smaller than the diameter of the clamping space.

[0015] As a further description of the above technical solution, the clamping claw is extended in the horizontal direction.

[0016] As a further description of the above technical solution, the first mold, the second mold and the third mold each include a main mold and a punching die that are correspondingly arranged;

[0017] The main mold includes a main mold shell, a main mold cushion block, a main mold ejector pin and a main mold core arranged in the main mold shell, the main mold core has a main mold cavity opening toward the punching die, and the main mold ejector pin is arranged through the main mold cushion block;

[0018] The die includes a die shell, a die pad and a die ejector arranged in the die shell, one end of the die ejector is connected to the die pad, and the other end of the die ejector is opposite to the main die cavity.

[0019] As a further description of the above technical solution, the main mold of the third mold also includes a main mold push rod, which passes through the main mold pad. The top end of the main mold push rod is abutted against the bottom end of the push tube sleeved on the main mold ejector pin, and the top end of the push tube is abutted against the end face of the circular flange facing the rod body.

[0020] As a further description of the above technical solution, a main mold sleeve is provided inwardly extending from the top end of the main mold ejector pin, and the bottom end of the main mold ejector pin is connected to the main mold spring in the main mold sleeve.

[0021] As a further description of the above technical solution, one end of the die of the third mold is further provided with a die cutter, and the die cutter is opposite to the main mold core;

[0022] A die sleeve is provided in the die pad, and one end of the die ejector pin is connected to the die spring of the die sleeve.

[0023] The outstanding effects of the present invention are:

[0024] The two clamping jaws are arranged opposite to each other in a cold heading device for processing parts provided by the present invention, and the relative clamping parts included in the two clamping jaws are both fitted with the side surfaces of the circular flange, forming a clamping space adapted to the circular flange to transfer the processing parts, and at the same time, the relative abutting parts included are abutted against the table surface of the circular flange facing away from the rod body, and together form a stop table adapted thereto to effectively block the table surface of the circular flange, ensuring that the clamping jaws will not cause the processing parts to fly out when the processing parts are processed at high speed, and the clamping is more stable; and the clamping jaws are opened from their outer edges along the radial direction of the circular flange to release the material, and compared with the original clamping jaws, the time for opening from the outer diameter of the rod to the outer diameter of the circular flange is reduced, thereby avoiding the collision between the clamping jaws and the mold, and smoothly passing the processing part to the third mold, realizing the automated over-molding between the second mold and the third mold, and gradually extruding the circular flange into a toothed flange on the third mold, and also avoiding the use of a punch press to punch out the toothed flange separately, thereby improving the processing efficiency;

[0025] In the cold heading device for workpieces provided by the present invention, the punch die ejector pin of the third mold is connected to the punch die spring, and the main mold ejector pin is connected to the main mold spring, which can cooperate to receive the workpiece transferred by the clamping claw assembly, thereby ensuring the stability and effectiveness of the over-mold process. Also, due to its smooth over-mold process, when the distance between the punch die cutter and the main mold core reaches a preset value, the main mold ejector rod can drive the push tube to instantly form an impact force, breaking through the skin of the toothed flange and the waste material on its edge to obtain a finished part with a full toothed flange without burrs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1This is a schematic structural diagram of a finished workpiece in an embodiment of the present invention;

[0028] Figure 2 This is a top view of a finished workpiece in an embodiment of the present invention;

[0029] Figure 3 This is a schematic structural diagram of a third mold in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the structure in which two clamping jaws are arranged opposite to each other in an embodiment of the present invention;

[0031] Figure 5 A partial cross-sectional view of a clamping jaw according to an embodiment of the present invention;

[0032] Figure 6 This is a diagram showing the working state of a clamping jaw clamping a circular flange in an embodiment of the present invention.

[0033] Reference numerals:

[0034] 1. Workpiece; 11. Rod; 12. Circular flange; 13. Toothed flange;

[0035] 2. Clamping claw; 21. Clamping portion; 22. Abutting portion; 23. Groove portion;

[0036] 31. Main mold shell; 32. Main mold spacer; 33. Main mold ejector pin; 34. Main mold core; 35. Main mold ejector pin; 36. Push tube; 37. Main mold sleeve; 38. Main mold spring;

[0037] 41. Die shell; 42. Die spacer; 43. Die ejector pin; 44. Die cutter; 45. Die sleeve; 46. Die spring. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] In the description of the present invention, it should be noted that the terms "upper", "middle", "lower", "inside", "outside", "front", "back" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. The terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The following describes an implementation method of the present invention based on its overall structure.

[0040] See also Figures 1 to 6 The present invention discloses a cold heading device for a workpiece 1, wherein the workpiece 1 includes a rod 11 and a circular flange 12 extending from one end of the rod 11, wherein the diameter of the circular flange 12 is greater than the length of the rod 11, and the cold heading device includes:

[0041] A first die for forming a straight section of a predetermined blank;

[0042] a second mold for forming the circular flange 12 at one end of the straight section and forming the rod body 11 at the other end of the straight section;

[0043] a third die for extruding the circular flange 12 into a toothed flange 13 and separating the toothed flange 13 from waste material at its outer edge;

[0044] Among them, a clamping jaw 2 assembly for over-molding the workpiece 1 is provided between the second mold and the third mold, and the clamping jaw 2 assembly includes at least two clamping jaws 2 arranged opposite to each other, and the clamping jaw 2 includes a clamping portion 21 that fits with the side of the circular flange 12, and a supporting portion 22 that fits with the table surface of the circular flange 12 away from the rod body 11. A clamping space adapted to the circular flange 12 is formed between the opposing clamping portions 21, and the opposing supporting portions 22 jointly form a stopper adapted to the table surface.

[0045] With the help of the above structure, when producing a tooth-shaped part, the operator can first use the first mold to form the preset blank into a straight section, and then use the second mold to form one end of the formed straight section into a circular flange 12, and the other end into the rod body 11 of the part, and then continue to use the third mold to gradually extrude the circular flange 12 into a tooth-shaped flange 13, and separate the outer edge waste from it to finally form the product.

[0046] Among them, the traditional over-molding clamping jaw 2 assembly can be used to over-mold the straight section between the first mold and the second mold, and the circular flange 12 formed in the second mold has a large diameter and a short rod body 11. If the original clamping jaw 2 of the original cold heading device is used to clamp it for over-molding, it is clamped on the rod body 11, which makes clamping difficult. At the same time, when moving to the third mold to discharge the material, the clamping jaw 2 does not have enough time to fully open, and is prone to collision with the components of the third mold. Therefore, in the original processing, it is impossible to use the cold heading device to directly form the toothed flange 13, and the toothed flange 13 needs to be punched out separately by a punch press. In the present embodiment, the two oppositely arranged clamping jaws 2 in the clamping jaw 2 assembly include the relative clamping portions 21 that are both in contact with the side surfaces of the circular flange 12, forming a clamping space transfer workpiece 1 that is compatible with the circular flange 12, and at the same time, the relative abutting portions 22 are both abutted against the table surface of the circular flange 12 that is away from the rod body 11, together forming a stop table that is compatible with it, and can also effectively block the table surface of the circular flange 12. This ensures that the workpiece 1 will not fly out when the clamping jaws 2 are over-molding the workpiece 1 at high speed, and the clamping is more stable; and the clamping jaws 2 open the material from the outer edge along the radial direction of the circular flange 12. Compared with the original clamping jaws 2, the opening time from the outer diameter of the rod body 11 to the outer diameter of the circular flange 12 is reduced, thereby avoiding the collision between the clamping jaws 2 and the mold, and the workpiece 1 is smoothly over-molded to the third mold, realizing the automated over-molding between the second mold and the third mold, and gradually extruding the circular flange 12 into the toothed flange 13 on the third mold, which also avoids the use of a punch press to punch out the toothed flange 13 alone, thereby improving the processing efficiency.

[0047] See also Figure 3 Specifically, in this embodiment, the first mold (not shown in the figure), the second mold (not shown in the figure) and the third mold all include a main mold and a punching die set accordingly;

[0048] The main mold includes a main mold shell 31, a main mold cushion block 32, a main mold ejector pin 33 and a main mold core 34 arranged in the main mold shell 31. The main mold core 34 has a main mold cavity with an opening facing the punching die. The main mold ejector pin 33 is arranged through the main mold cushion block 32.

[0049] The die includes a die shell 41 , a die pad 42 and a die ejector pin 43 disposed in the die shell 41 , one end of the die ejector pin 43 is connected to the die pad 42 , and the other end of the die ejector pin 43 is opposite to the main die cavity.

[0050] See also Figure 5Specifically, during the cold heading process, the main mold ejector 33 of the second mold pushes the workpiece 1 out of its main mold core 34, and the clamping space formed by the clamping jaws 2 is opposite to the main mold cavity of the second mold to wait for material connection. The workpiece 1 after processing by the second mold includes a circular flange 12 and a rod body 11. The diameter of the circular flange 12 is 21 mm, and the length of the rod body 11 is only 7.5 mm, which is much smaller than the diameter of the circular flange 12. When receiving the material, the clamping jaws 2 only clamp the side of the circular flange 12, so that the circular flange 12 is accommodated in the clamping space, which is convenient for discharging the material to the third mold.

[0051] See also Figures 4 to 6 Specifically, in this embodiment, the clamping portion 21 is an arcuate surface. When in the clamping state, the arcuate surface forms surface contact with the side surface of the circular flange 12. The arcuate surface design enables the clamping jaws 2 to embrace the outside of the workpiece 1, playing a fixed role, thereby ensuring stable clamping of the workpiece 1. It should be understood that the horizontal length of the clamping portion 21 can be set according to the thickness of the circular flange 12 to meet the clamping requirements.

[0052] Please continue reading Figure 3 Specifically, in this embodiment, each of the main molds and the punching die is arranged horizontally. The clamping jaws 2 arranged between adjacent molds extend in the horizontal direction. During the clamping process, the clamping jaws 2 embrace the circumference of the circular flange 12, and because the clamping portion 21 thereof is an arc-shaped surface, it has a supporting effect on the bottom of the circular flange 12 and a limiting effect on the two sides of the circular flange 12. Preferably, the clamping jaws 2 include two, which are arranged horizontally on both sides of the workpiece 1 relative to each other.

[0053] See 3 and Figure 4Specifically, in this embodiment, the stop platform formed by the supporting portion 22 has an avoidance portion, which is formed by the two supporting portions 22 being recessed inward, and the width of the avoidance portion is smaller than the diameter of the circular flange 12, so that the two supporting portions 22 can effectively stop the circular flange 12 while also ensuring effective avoidance of the punch ejector pin 43 of the third mold. Specifically, the clamp 2 moves the workpiece 1 to the die mouth of the third mold, that is, the position opposite to the main mold cavity of the third mold, and the main mold ejector 33 of the third mold abuts against the end of the rod body 11 of the workpiece 1 away from the circular flange 12, and the die ejector 43 of the third mold can also pass through the avoidance part as the third mold moves, and then abut against the table surface of the circular flange 12, and cooperate with the main mold ejector 33 to smoothly receive the workpiece 1. In the process of the die ejector 43 continuing to approach the main mold ejector 33, the clamp 2 has enough time to open to avoid collision with the die parts, thereby realizing the automated over-molding of the workpiece 1.

[0054] Please continue reading Figures 4 to 6 Specifically, in this embodiment, the clamping jaw 2 further includes a groove portion 23 for accommodating the rod 11. An accommodating space is formed between the opposing groove portions 23 for accommodating the rod 11. The diameter of the accommodating space is larger than the outer diameter of the rod 11 and slightly smaller than the diameter of the clamping space. While not in contact with the rod 11, the accommodating space can cooperate with the abutting portion 22 to limit the circular flange 12 in the horizontal direction, ensuring stable clamping. Since the diameter is only slightly smaller than the diameter of the clamping space, the clamping jaw 2 as a whole can smoothly avoid collision with the die.

[0055] Please continue reading Figure 3 Specifically, in this embodiment, the main mold of the third mold further includes a main mold ejector pin 35. The main mold ejector pin 35 is provided through the main mold cushion block 32. The top end of the main mold ejector pin 35 abuts against the bottom end of a push tube 36 sleeved on the main mold ejector pin 33. The top end of the push tube 36 abuts against the end surface of the circular flange 12 facing the rod body 11. A main mold sleeve 37 is provided inwardly extending from the top end of the main mold ejector pin 33. The bottom end of the main mold ejector pin 33 is connected to the main mold spring 38 within the main mold sleeve 37. A die cutter 44 is also provided at one end of the punch of the third mold. The die cutter 44 is opposite to the main mold core 34. A die sleeve 45 is provided within the punch cushion block 42. One end of the punch ejector pin 43 is connected to the die spring 46 of the punch sleeve 45.

[0056] When receiving the workpiece 1 transferred by the clamp 2, the punch ejector pin 43 and the main mold ejector pin 33 respectively press against the table surface of its circular flange 12 and the end surface of the rod body 11 away from the circular flange 12. At the same time, due to the presence of the punch spring 46 and the main mold spring 38, the two ejectors can stably maintain the support effect on the workpiece 1. In this way, the clamp 2 can open to avoid the punch cutter 44. As the punch gradually approaches the main mold, the workpiece 1 is slowly pushed into the main mold cavity of the main mold core 34. Under the extrusion of the punch cutter 44 and the main mold core 34, the circular flange 12 is gradually formed into the toothed flange 13. When the distance between the punch cutter 44 and the main mold core 34 reaches the preset value, the main mold ejector pin 35 will drive the push tube 36, instantly forming an impact force to break the toothed flange 13 and the waste material on its edge. Thus, the bisection is completed, and the result is as shown below. Figure 1 and Figure 2 The finished part is shown, and its toothed flange 13 is fully formed; then the die retreats, gradually moving away from the main die, and under the action of the die spring 46, the die ejector pin 43 is displaced relative to the die pad 42, and continues to cooperate with the main die ejector pin 33 to retain the finished part in the main die cavity, until the die ejector pin 43 leaves the table surface of the toothed flange 13, the elastic force of the die spring 46 is 0, and the main die ejector pin 33, under the elastic force of the main die spring 38, pushes the finished part out of the main die cavity, causing it to fall into the material gate slide. For example, in this embodiment, the distance between the die cutter 44 and the main die core 34 can be preset to 0.5mm. At this time, the main die ejector pin 35 drives the push tube 36 to impact, breaking the 0.5mm thick skin, so that the toothed flange 13 and the waste material on its outer edge are directly separated without generating burrs.

[0057] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any changes, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A cold heading device for a workpiece, wherein: The workpiece includes a rod body and a circular flange extending from one end of the rod body, wherein the diameter of the circular flange is greater than the length of the rod body, and is characterized in that the cold heading device includes: A first die for forming a straight section of a predetermined blank; a second mold for forming the circular flange at one end of the straight section and forming the rod body at the other end of the straight section; a third die for extruding the circular flange into a toothed flange and separating the toothed flange from waste material at its outer edge; A clamping jaw assembly for overmolding the workpiece is provided between the second mold and the third mold, the clamping jaw assembly comprising at least two oppositely arranged clamping jaws, the clamping jaws comprising a clamping portion abutting against the side surface of the circular flange, and an abutting portion abutting against the table surface of the circular flange facing away from the rod body, a clamping space adapted to the circular flange is formed between the opposing clamping portions, and the opposing abutting portions jointly form a stopper adapted to the table surface; The first mold, the second mold, and the third mold each include a main mold and a punching die arranged accordingly; the main mold includes a main mold shell, a main mold pad, a main mold ejector, and a main mold core arranged in the main mold shell, the main mold core having a main mold cavity opening toward the punching die, and the main mold ejector penetrating the main mold pad; the punching die includes a punching die shell, a punching die pad and a punching die ejector arranged in the punching die shell, one end of the punching die ejector connected to the punching die pad, and the other end of the punching die ejector facing the main mold cavity; The main mold of the third mold also includes a main mold push rod, which passes through the main mold cushion block, and the top of the main mold push rod is against the bottom end of the push tube sleeved on the main mold ejector pin, and the top of the push tube is against the end face of the circular flange facing the rod body; the top end of the main mold push rod is extended inwardly to provide a main mold sleeve, and the bottom end of the main mold ejector pin is connected to the main mold spring in the main mold sleeve; one end of the punch of the third mold is also provided with a punch cutter, and the punch cutter is opposite to the main mold core; a punch sleeve is provided in the punch cushion block, and one end of the punch ejector pin is connected to the punch spring of the punch sleeve; when the third mold receives the workpiece transferred by the clamp, its punch The die ejector pin and the main die ejector pin are respectively stabilized against the table surface of the circular flange of the workpiece and the end face of the rod body facing away from the circular flange by means of the punch die spring and the main die spring, so that the clamping jaws can be opened to avoid the punch die cutter; as the punch die gradually approaches the main die, the workpiece is pushed into the main die cavity of the main die core, and its circular flange is gradually formed into the tooth-shaped flange under the extrusion of the punch die cutter and the main die core; when the distance between the punch die cutter and the main die core reaches 0.5mm, the main die ejector rod will drive the push tube to form an instantaneous impact force, breaking the tooth-shaped flange and its edge waste to complete the cutting, and then the punch die retreats to move away from the main die.

2. The cold heading device for workpieces according to claim 1, characterized in that: When the workpiece in the second mold is in a demolding state, the clamping space is arranged opposite to the main mold cavity of the second mold.

3. The cold heading device for workpiece according to claim 1, characterized in that: The stop platform has an avoidance portion, and the avoidance portion is formed by the two supporting portions being recessed inwardly.

4. The cold heading device for workpieces according to claim 1, characterized in that: The clamping portion is an arc-shaped surface.

5. The cold heading device for workpiece according to claim 1, characterized in that: The clamping jaws further include groove portions for accommodating the rod, and an accommodating space for accommodating the rod is formed between the opposing groove portions. The diameter of the accommodating space is larger than the outer diameter of the rod and smaller than the diameter of the clamping space.

6. The cold heading device for workpieces according to claim 1, characterized in that: The clamping claws are extended in a horizontal direction.

Images