Zero-clearance cold heading die

Abstract

The invention provides a zero-clearance cold heading die, and belongs to the technical field of cold heading machining. The movable die and the cushion block seat are arranged at the two ends of the barrel inner cavity of the die shell correspondingly, the movable die is sleeved with the steel ball bush and the adjusting bush, meanwhile, the inner contour of one end of the barrel inner cavity and the outer contour of the adjusting bush are arranged in a conical shape, and the conical surfaces of the two cones are tightly attached; the steel ball bushings are arranged on the two ends of the adjusting bushings, and the adjusting pieces which abut against the adjusting bushings are arranged at the two ends of the adjusting bushings respectively, so that abrasion can be reduced during movement of the movable die through the steel ball bushings, the service life is prolonged, and meanwhile the adjusting bushings are pushed by the adjusting pieces to move at the corresponding positions in the inner cavity of the cylinder, so that the adjusting bushings can contract and extrude the steel ball bushings. According to the technical scheme, the assembly clearance among the movable die, the steel ball bushing, the adjusting bushing and the die shell is eliminated, the zero-clearance assembly requirement is met, the movement requirement of the movable die during zero-clearance assembly is met through the steel ball bushing, the assembly and use precision is improved, the product quality is guaranteed, and the machining requirement of high-end precision products is met.

Description

Technical Field

[0001] The invention relates to the technical field of cold heading processing, in particular to a zero-gap cold heading die. Background Art

[0002] The cold heading forming process is a technology that applies pressure to metal materials in a cold state to deform them in a mold. It is usually used in the production of standard parts such as bolts, nuts, and sleeves. The cold heading die, as a structure that applies pressure to metal materials and controls the deformation state, plays a decisive role in the cold heading quality of the product.

[0003] At present, the structure of the cold heading die commonly used in the market is such as a cold heading die for reducing diameter of hardware disclosed in patent CN222001748U, which includes an upper die and a lower die, the upper die includes an upper die body with a groove and a reducing hole, the lower die includes a lower die seat, a ejector is provided through the lower die seat, a push tube is provided on the ejector, a cylindrical movable die core and a reset spring are provided on the push tube, and the reset spring abuts between the cylindrical movable die core and the lower die seat, a groove connected to the inner ring of the cylindrical movable die core is provided on the top of the cylindrical movable die core, a cylindrical insert is provided in the groove, and the cylindrical insert is sleeved on the push tube The upper mold body moves toward one side of the lower mold body, and the upper mold body drives the cylindrical movable mold core to move downward and compress the reset spring. One end of the hardware is formed under the cold heading of the groove and the reducing hole, and the cylindrical insert can prevent other parts of the hardware at this end from deforming and support this end of the hardware through the push tube. When the mold is opened, the movable model can be reset under the elastic force of the reset spring, and the push tube is driven upward by pushing the ejector pin to eject the product from the lower mold to meet the cold heading processing requirements. Although the above structure can realize cold heading processing, the inner wall of the barrel cavity of the cylindrical mold shell is directly in contact with the outer wall of the movable mold core, and in order to realize the relative movement of the movable mold core in the cylindrical mold shell and facilitate the disassembly and assembly of the two, the size of the barrel cavity of the cylindrical mold shell is usually slightly larger than the size of the movable mold core. For example, a gap of 0.05mm is reserved between the two to ensure that the movable mold core can slide smoothly in the cylindrical mold shell, resulting in a decrease in the matching accuracy of the movable mold core and the cylindrical mold shell, which not only affects the processing quality of the product and cannot meet the processing requirements of high-precision parts, but also easily leads to increased wear between the two, affecting the service life of the cold heading mold. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present invention aims to provide a cold heading die with zero clearance. A steel ball bushing and an adjusting bushing are arranged between the die shell and the movable die. The adjusting bushing is coaxially sleeved outside the steel ball bushing, and the steel ball bushing is sleeved outside the movable die. The outer side wall of the adjusting bushing abuts against the inner side wall of the cylindrical inner cavity of the die shell, so that the movement of the movable die in the die shell can be supported and guided by the steel ball bushing and the adjusting bushing, reducing wear. Moreover, the cylindrical inner cavity of the die shell is a conical structure, and the outer contour of the adjusting bushing is also a conical structure. Adjusting members are respectively arranged on the die shell and the cushion block seat and abut against both ends of the adjusting bushing. By adjusting the adjusting members at both ends of the adjusting bushing, the position change of the adjusting bushing in the cylindrical inner cavity of the die shell is realized, and the adjusting bushing is extruded or relaxed through the mutual cooperation of their conical surfaces, thereby adjusting the clearance between the steel ball bushing and the movable die, meeting the zero-clearance fit requirement. And when the two are in zero-clearance fit, the relative movement requirement is adapted by the steel ball bushing, thus avoiding the problems of low product precision, easy wear and short service life caused by assembly and movement clearances while meeting the cold heading processing requirements.

[0005] The specific technical solutions are as follows: A cold heading die with zero clearance, comprising a die shell and a movable die. The die shell has a through cylindrical inner cavity, and the movable die is arranged in the cylindrical inner cavity at one end of the die shell. A cushion block seat is arranged in the cylindrical inner cavity at the other end of the die shell. It has the following characteristics: it further includes a steel ball bushing and an adjusting bushing. The steel ball bushing and the adjusting bushing are coaxially arranged and the adjusting bushing is sleeved outside the steel ball bushing. The steel ball bushing is sleeved outside the movable die. Moreover, the outer side wall of the adjusting bushing fits with the inner side wall of the cylindrical inner cavity. At the same time, the inner contour of the cylindrical inner cavity of the die shell at the end where the movable die is arranged and the outer contour of the adjusting bushing are both arranged in a conical shape, and the outer conical surface of the adjusting bushing fits with the inner conical surface of the cylindrical inner cavity. And adjusting members are arranged on both the end of the die shell where the movable die is arranged and the cushion block seat and respectively abut against both ends of the adjusting bushing.

[0006] In the above-mentioned cold heading die with zero clearance, an upper mounting ring is arranged at the cavity opening of the cylindrical inner cavity at the end of the die shell where the movable die is arranged. The adjusting member at the end of the die shell where the movable die is arranged is arranged on the upper mounting ring. Moreover, the interval between the upper mounting ring and the cushion block seat is greater than the axial length of the adjusting bushing.

[0007] In the above-mentioned cold heading die with zero clearance, the movable die is a stepped shaft. The large head end of the movable die is located in the cylindrical inner cavity, the upper mounting ring is sleeved outside the small head end of the movable die, and the small head end of the movable die extends outside the upper mounting ring.

[0008] The above cold heading die with zero clearance, wherein the inner cavity of the cylinder is a stepped hole, the cross-section of the end of the inner cavity of the cylinder where the spacer seat is arranged is larger than the cross-section of the end where the movable die is arranged, and the large end of the tapered section of the inner cavity of the cylinder is the end close to the spacer seat.

[0009] The above cold heading die with zero clearance, wherein one end of the spacer seat abuts against the inner step of the inner cylinder cavity.

[0010] The above cold heading die with zero clearance, wherein the adjusting member is a setscrew, and the adjusting members are respectively threadedly connected to the upper mounting ring and the spacer seat.

[0011] The above cold heading die with zero clearance, wherein each adjusting member includes a plurality of setscrews, and the plurality of setscrews in each adjusting member are arranged in a circular array with the axis of the adjusting bushing as the center.

[0012] The above cold heading die with zero clearance, wherein an oil filling hole penetrating the side wall is provided on the outer side wall of the die shell, and the oil filling hole communicates with the section of the inner cavity of the cylinder where the steel ball bushing and the adjusting bushing are installed.

[0013] The above cold heading die with zero clearance, further comprising a pre-fixing assembly installed on the die shell. The pre-fixing assembly includes a limit pin and a pressing sleeve. A limit hole is provided on the outer side wall of the die shell and at the end of the adjusting bushing close to the spacer seat. The limit pin is slidably arranged in the limit hole and one end abuts against the outer side wall of the adjusting bushing. At the same time, the other end of the limit pin extends outside the die shell. The pressing sleeve is coaxially sleeved outside the die shell and moves axially along the adjusting bushing. The inner cavity of one end of the pressing sleeve is tapered. The end of the limit pin extending outside the die shell abuts against the tapered surface of the inner cavity of the pressing sleeve.

[0014] The above cold heading die with zero clearance, wherein a protruding adjusting ring is provided on the outer side wall of the die shell. An external adjusting thread is provided on the adjusting ring along the axial direction of the adjusting bushing. An internal adjusting thread is provided on the inner wall of the inner cavity of the pressing sleeve and at the end away from the tapered arrangement. The pressing sleeve is in threaded cooperation with the adjusting ring. At the same time, a plurality of operating planes are distributed along the circumferential direction of the outer side wall of the pressing sleeve.

[0015] The positive effects of the above technical solutions are: The above cold heading die with zero clearance has a movable die slidably arranged at one end of the cylindrical inner cavity of the die shell, a spacer seat arranged at the other end, and a steel ball bushing and an adjusting bushing are also arranged at the end of the cylindrical inner cavity where the movable die is located. The adjusting bushing is coaxially sleeved outside the steel ball bushing, and the steel ball bushing is sleeved outside the movable die. By using the steel ball bushing and the adjusting bushing as the support and guiding structure when the movable die slides in the die shell, wear is reduced. In addition, the inner contour of the end of the cylindrical inner cavity where the movable die is located and the outer contour of the adjusting bushing are both arranged in a conical shape, and the outer conical surface of the adjusting bushing fits with the inner conical surface of the cylindrical inner cavity. Adjusting members are arranged at the end of the die shell where the movable die is located and on the spacer seat and respectively abut against both ends of the adjusting bushing, so that the position of the adjusting bushing in the cylindrical inner cavity can be adjusted through the adjusting members, and the adjusting bushing presses or relaxes the steel ball bushing through the cooperation of the conical surfaces, thereby realizing the adjustment of the clearance between the movable die, the steel ball bushing, the adjusting bushing and the die shell, meeting the assembly requirement of zero clearance, improving the assembly and use accuracy, being able to adapt to the processing of high-precision products while meeting the cold heading processing requirements, reducing wear and prolonging the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Structural diagram of an embodiment of a cold heading die with zero clearance according to the present invention; Figure 2 is Figure 1 Enlarged view of part A in

[0017] In the drawings: 1. Die shell; 11. Cylindrical inner cavity; 12. Upper mounting ring; 13. Oil filling hole; 14. Limiting hole; 15. Adjusting ring; 2. Movable die; 3. Spacer seat; 4. Steel ball bushing; 5. Adjusting bushing; 6. Adjusting member; 7. Pre-fixing assembly; 71. Limiting pin; 72. Compression sleeve; 721. Operating plane. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the following embodiments are combined with the attached Figure 1 to the attached Figure 2 to specifically elaborate on the technical solutions provided by the present invention, but the following content is not a limitation of the present invention.

[0019] Figure 1 Structural diagram of an embodiment of a cold heading die with zero clearance according to the present invention. As Figure 1 shown, the cold heading die with zero clearance provided in this embodiment includes: a die shell 1, a movable die 2, a steel ball bushing 4, an adjusting bushing 5 and an adjusting member 6.

[0020] Specifically, the die shell 1 is a cylindrical structure. At this time, the die shell 1 has a through cylindrical inner cavity 11, and the movable die 2 is arranged in the cylindrical inner cavity 11 at one end of the die shell 1. At the same time, a cushion block seat 3 is arranged in the cylindrical inner cavity 11 at the other end of the die shell 1. By sliding the movable die 2 in the cylindrical inner cavity 11 of the die shell 1, the die shell 1 serves as a guiding structure for the movement of the movable die 2, maintaining the stability of the movable die 2 during cold heading, realizing the relative movement between the movable die 2 and the cushion block seat 3, and thus realizing the cold heading operation of the metal material. Moreover, different types and quantities of cushion block seats 3 can be replaced to adapt to the processing of products with different specifications and models, making the structure more flexible. In addition, the steel ball bushing 4 and the adjusting bushing 5 are coaxially arranged, and the adjusting bushing 5 is sleeved on the outside of the steel ball bushing 4, that is, the adjusting bushing 5 can support and guide the steel ball bushing 4 and apply a radial force to maintain the stability of the steel ball bushing 4. At the same time, the steel ball bushing 4 is sleeved on the outside of the movable die 2, that is, the steel ball bushing 4 provides support and guidance for the movement of the movable die 2, improving the stability of the movable die 2 during movement, preventing wear problems, and extending the service life. In addition, for subsequent zero-clearance fitting, the rotation of the steel balls in the steel ball bushing 4 can meet the use requirements of the movement of the movable die 2, and there will be no problem that it is difficult to slide when the movable die 2 and the die shell 1 are in direct contact and there is zero clearance between them in the traditional structure. Normal cold heading processing can still be maintained under the condition of meeting zero-clearance assembly. And the outer side wall of the adjusting bushing 5 is attached to the inner side wall of the cylindrical inner cavity 11, realizing the direct contact between the adjusting bushing 5 and the die shell 1.Meanwhile, the inner contour of the barrel inner cavity 11 of the die shell 1 at the end where the movable die 2 is arranged and the outer contour of the adjusting bushing 5 are both arranged in a conical shape, so that the cross-section of the end of the barrel inner cavity 11 cooperating with the movable die 2 gradually changes. Similarly, the outer diameter of the cross-section of the adjusting bushing 5 also gradually changes, so that when the adjusting bushing 5 is installed in the barrel inner cavity 11, the outer conical surface of the adjusting bushing 5 fits with the inner conical surface of the barrel inner cavity 11. In addition, adjusting members 6 are arranged at both the end of the die shell 1 where the movable die 2 is arranged and the pad seat 3, and the two adjusting members 6 respectively abut against both ends of the adjusting bushing 5. That is, when adjusting the two adjusting members 6, the axial movement of the adjusting bushing 5 along its own axis can be realized, so that the outer conical surface of the adjusting bushing 5 will push against the inner conical surface of the barrel inner cavity embedded in the die shell 1. When the adjusting bushing 5 moves in the direction where the cross-section of the barrel inner cavity 11 becomes smaller, the adjusting bushing 5 will be gradually squeezed and shrink. Although the shrinkage amount is small, for an assembly gap generally of 0.05 mm, it can already meet the requirement of filling this assembly gap, thereby pushing the steel ball bushing 4 coaxially sleeved therein tightly against the outside of the movable die 2, thus eliminating the assembly gap between the movable die 2, the steel ball bushing 4, the adjusting bushing 5 and the die shell 1, realizing zero-gap assembly. And because the steel balls in the steel ball bushing 4 can also rotate under the extrusion force, it can ensure the sliding of the movable die 2 relative to the die shell 1 in the case of zero-gap assembly, avoiding the situation that the existing cold heading die needs to reserve an assembly gap to ensure the sliding of the movable die 2 relative to the die shell 1. It can not only improve the stability of the movable die 2 during movement but also improve the assembly accuracy, thereby improving the processing quality of the product and meeting the processing requirements of high-precision products. In addition, the wear is also reduced by the steel ball bushing 4, and the service life of the die is extended. It should be noted that because the steel balls have certain elasticity and resilience, they can absorb and buffer part of the impact force and vibration during the cold heading process, reduce the impact on the die and related equipment, improve the stability of the production environment and the reliability of the equipment, and also extend the service life.

[0021] More specifically, an upper mounting ring 12 is also provided at one end of the mold shell 1 where the movable mold 2 is provided. At this time, the upper mounting ring 12 is provided at the cavity opening of the barrel inner cavity 11, that is, a constriction structure is formed at the cavity opening of the barrel inner cavity 11 at one end of the mold shell 1 where the movable mold 2 is provided, which can not only prevent the subsequent excessive movement of the movable mold 2, but also provide a carrier for the installation of the subsequent adjustment member 6. During assembly, the adjustment member 6 at one end of the mold shell 1 where the movable mold 2 is provided is provided on the upper mounting ring 12 to ensure that the adjustment member 6 abutting against one end of the adjustment bushing 5 can be installed on the mold shell 1 through the upper mounting ring 12. In addition, the interval between the upper mounting ring 12 and the pad seat 3 is set to be greater than the axial length of the adjustment bushing 5, so that the adjustment bushing 5 can be axially moved relative to the mold shell 1 under the action of the adjustment members 6 at both ends, meeting the use requirements of the adjustable position of the adjustment bushing 5, thereby realizing zero-clearance assembly. As a preferred embodiment, the upper mounting ring 12 and the mold shell 1 are an integrated structure with better integrity, higher structural strength, and stronger bearing capacity, which meets the requirements of limiting and being used as a mounting carrier for the adjustment member 6.

[0022] More specifically, the movable mold 2 is a stepped shaft, that is, the cross-sectional dimensions of the movable mold 2 in the axial direction vary. Preferably, the movable mold 2 is provided with two sections, in which case the large end of the movable mold 2 is provided in the barrel cavity 11, and the upper mounting ring 12 is sleeved outside the small end of the movable mold 2, that is, a limiting step surface can be formed between the two sections of the movable mold 2, so that when the movable mold 2 is installed in the mold shell 1, the small end of the movable mold 2 extends to the outside of the upper mounting ring 12, and the upper mounting ring 12 can not only guide the movement of the movable mold 2, but also prevent the problem of excessive movement of the movable mold 2 by cooperating with the limiting step surface formed on the movable mold 2, so that the movable mold 2 can only move a predetermined distance in the mold shell 1, which can meet the cold heading requirements and maintain the reliability of the overall structure, and the structural design is more reasonable.

[0023] More specifically, the barrel inner cavity 11 of the mold shell 1 is a stepped hole, so that a limiting step can also be formed in the barrel inner cavity 11. At this time, the cross-section of the end of the barrel inner cavity 11 where the block seat 3 is provided is larger than the cross-section of the end where the movable mold 2 is provided, and the large head end of a section of the barrel inner cavity 11 of the mold shell 1 arranged in a cone is set to be close to the end of the block seat 3, ensuring that the cross-sectional size of the entire barrel inner cavity 11 always maintains a direction from large to small or from small to large in its axial direction, thereby facilitating the installation of the movable mold 2, the steel ball bushing, the adjustment bushing 5 and the block seat 3 from the large head end of the barrel inner cavity 11 into the barrel inner cavity 11, making disassembly and assembly more convenient.

[0024] More specifically, one end of the spacer seat 3 is abutted against the internal step of the inner cylinder cavity. That is, when the spacer seat 3 is installed in the cylinder inner cavity 11 of the formwork 1, the installation can be limited by the internal step formed in the cylinder inner cavity 11, ensuring the accurate installation position of the spacer seat 3, maintaining the stable distance between the spacer seat 3 and the upper mounting ring 12, and avoiding the problem that the movable mold 2 has no space to move due to excessive extrusion, and the structural design is more reasonable.

[0025] More specifically, the adjusting members 6 for pushing against both ends of the adjusting bushing 5 are both setscrews. And the adjusting members 6 are respectively threadedly connected to the upper mounting ring 12 and the spacer seat 3. That is, during assembly or after being worn after using for a period of time, if there is an assembly gap, the operator can push the adjusting bushing 5 to move in the cylinder inner cavity 11 of the formwork 1 by screwing the corresponding adjusting member 6, so that the adjusting bushing 5 can contract and then push the steel ball bushing 4 to closely contact the movable mold 2, realizing zero-clearance assembly and being more convenient to adjust.

[0026] More specifically, each end of the adjusting bushing 5 has several setscrews as the adjusting member 6. At this time, the several setscrews in each adjusting member 6 are annularly arrayed with the axis of the adjusting bushing 5 as the center, so that each end of the adjusting bushing 5 has multiple evenly distributed setscrews to push against, making the adjusting bushing 5 more evenly stressed and having more stress points, and the structural stability and reliability are higher.

[0027] More specifically, an oil filling hole 13 penetrating the side wall is also opened on the outer side wall of the formwork 1. At the same time, the oil filling hole 13 is communicated with a section of the cylinder inner cavity 11 where the steel ball bushing 4 and the adjusting bushing 5 are installed, so that when lubricating oil needs to be added between the steel ball bushing 4, the adjusting bushing 5 and the movable mold 2, it can be added through the oil filling hole 13, which is more convenient to use. It should be noted that the oil filling hole 13 is located at the upper end of the formwork 1, so that the lubricating oil filled through the oil filling hole 13 is not easy to flow back from the oil filling hole 13 after entering the cylinder inner cavity 11, and the lubricating oil can flow downward under the action of its own gravity, so as to realize the lubrication of the adjusting bushing 5, the steel ball bushing 4 and the movable mold 2 during movement in the cylinder inner cavity 11, reduce wear and extend the service life. And the oil filling hole 13 is a hole inclined along the axial direction of the adjusting bushing 5, and the orifice of the oil filling hole 13 communicated with the cylinder inner cavity 11 is lower than the orifice on the outer side wall of the formwork 1, so that when lubricating oil is filled through the oil filling hole 13, the lubricating oil can automatically flow into the cylinder inner cavity 11 along the oil filling hole 13, avoiding reverse flow.

[0028] Figure 2 is Figure 1 the enlarged view of part A in. As Figure 1 and Figure 2As shown in the figure, a pre-fixing component 7 is further provided on the formwork 1. Since the cushion block seat 3 with the adjusting member 6 is located in the cylindrical inner cavity 11 of the formwork 1 and will be covered by other structures such as the cushion block seat 3 later, it is necessary to disassemble the above covering structures every time when adjusting the adjusting member 6 on the cushion block seat 3, and the adjustment process is relatively cumbersome. Therefore, every time when adjusting, it is necessary to minimize the disassembly and assembly frequency. Therefore, every time when adjusting, it is necessary to ensure that the adjustment is in place before installing the above covering structure into the formwork 1. At this time, the pre-fixing component 7 is installed on the formwork 1, and the pre-fixing component 7 further includes a limit pin 71 and a pressing sleeve 72. In addition, a limit hole 14 is opened on the outer side wall of the formwork 1 and at one end of the adjusting bush 5 close to the cushion block seat 3. The limit hole 14 penetrates through the side wall of the formwork 1, and a limit pin 71 is slidably arranged in the limit hole 14, and one end of the limit pin 71 abuts against the outer side wall of the adjusting bush 5, so that when the limit pin 71 is pressed towards the adjusting bush 5, the limit pin 71 can press the adjusting bush 5, and the axial or circumferential movement of the adjusting bush 5 is restricted by the limit pin 71, realizing the temporary limit of the adjusting bush 5. At this time, the movable die 2 can be pulled, and whether the steel ball bush 4 and the adjusting bush 5 are adjusted in place can be judged by the movement state of the movable die 2. If not, the adjusting member 6 is continued to be operated until the adjustment is completed, so that the test can be carried out without completely assembling the above covering structure in place during the test, avoiding the cumbersome operation problem caused by re-disassembling and then adjusting when the adjustment is not in place after the above covering structure is completely assembled in place, and it is more convenient to use. In addition, it can also be used as an auxiliary positioning structure during subsequent use, further improving the installation stability of the adjusting bush 5 and the steel ball bush 4. At the same time, the other end of the limit pin 71 extends outside the formwork 1, and the pressing sleeve 72 is coaxially sleeved outside the formwork 1 and moves along the axial direction of the adjusting bush 5. And, the inner cavity of one end of the pressing sleeve 72 is arranged in a conical shape. At the same time, the end of the limit pin 71 extending outside the formwork 1 abuts against the conical surface of the inner cavity of the pressing sleeve 72, so that when the pressing sleeve 72 moves along the axial direction of the adjusting bush 5, the pressing sleeve 72 can push the limit pin 71 to move towards the side of the adjusting sleeve through its conical surface, so that the limit pin 71 abuts tightly against the adjusting sleeve, thereby realizing the temporary positioning of the adjusting sleeve, and the test requirements can be met without assembling other covering structures, so that after the test is completed and the use requirements are met, other covering structures are assembled into the formwork 1, so that only one disassembly and assembly of other covering structures is required for each adjustment, and the operation is more convenient.

[0029] More specifically, a protruding adjustment ring 15 is provided on the outer wall of the mold shell 1. The outer diameter of the mold shell 1 is thickened by the adjustment ring 15, so that the outer walls of other parts of the mold shell 1 are located on the inner side of the adjustment ring 15, so as to prevent the subsequent clamping sleeve 72 from smoothly passing through other parts of the mold shell 1 and cooperating with the adjustment ring 15. At the same time, an adjustment outer thread is provided on the adjustment ring 15 along the axial direction of the adjustment bushing 5, and an adjustment inner thread is provided on the inner wall of the sleeve inner cavity of the clamping sleeve 72 and at the end away from the conical arrangement. When the clamping sleeve 72 is installed outside the adjustment ring 15 of the mold shell 1, the adjustment inner thread of the clamping sleeve 72 cooperates with the adjustment outer thread of the adjustment ring 15, which can not only facilitate the axial movement of the clamping sleeve 72 relative to the mold shell 1, but also realize self-locking, and prevent the limit pin 71 from pushing the clamping sleeve 72 in the opposite direction to reverse and cause the temporary positioning failure. At the same time, multiple operating planes 721 are distributed along the circumference of the outer wall of the compression sleeve 72, and each operating plane 721 is arranged along the tangent direction of the compression sleeve 72. Preferably, the multiple operating planes 721 are distributed in a regular hexagon, which is convenient for tightening the compression sleeve 72 with the help of tools such as an open-end wrench, making the operation more convenient.

[0030] The zero-gap cold heading die provided in this embodiment comprises a die shell 1, a movable die 2, a steel ball bushing 4, an adjusting bushing 5 and an adjusting member 6; the movable die 2 and the cushion block seat 3 are respectively arranged at the two ends of the barrel inner cavity 11 of the die shell 1, and the outer sleeve of the movable die 2 is provided with a steel ball bushing 4, and the outer sleeve of the steel ball bushing 4 is provided with an adjusting bushing 5, at the same time, the inner contour of the end of the barrel inner cavity 11 provided with the movable die 2 and the outer contour of the adjusting bushing 5 are both arranged in a conical shape, and the conical surfaces of the two are tightly attached, and the cushion block seat 3 and the end of the die shell 1 provided with the movable die 2 are respectively provided with the adjusting bushing 5. The adjusting pieces 6 at both ends of the sleeve 5 allow the movement of the movable mold 2 to reduce wear through the steel ball bushing 4 and extend its service life. At the same time, the adjusting piece 6 pushes the adjusting bushing 5 to move to the corresponding position in the cylinder cavity 11, so that the adjusting bushing 5 can shrink and squeeze the steel ball bushing 4, thereby eliminating the assembly gap between the movable mold 2, the steel ball bushing 4, the adjusting bushing 5 and the mold shell 1, meeting the zero-gap assembly requirements, and adapting to the movement requirements of the movable mold 2 during zero-gap assembly through the steel ball bushing 4, thereby improving the assembly and use accuracy, ensuring product quality, and meeting the processing requirements of high-end precision products.

[0031] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A cold heading die with zero clearance, comprising a die shell and a movable die. The die shell has a through cylindrical inner cavity, the movable die is arranged in the cylindrical inner cavity at one end of the die shell, and a spacer seat is arranged in the cylindrical inner cavity at the other end of the die shell; it is characterized in that, It further includes: A steel ball bushing and an adjusting bushing. The steel ball bushing and the adjusting bushing are coaxially arranged, and the adjusting bushing is sleeved on the outside of the steel ball bushing. The steel ball bushing is sleeved on the outside of the movable die. Moreover, the outer side wall of the adjusting bushing is in contact with the inner side wall of the barrel cavity. At the same time, the inner contour of the end of the barrel cavity of the mold shell where the movable die is arranged and the outer contour of the adjusting bushing are both arranged in a conical shape. The outer conical surface of the adjusting bushing is in contact with the inner conical surface of the barrel cavity. And, adjusting members are provided at one end of the mold shell where the movable die is arranged and on the cushion block seat respectively and are abutted against both ends of the adjusting bushing.

2. The cold heading die with zero clearance according to claim 1, characterized in that, At the end of the mold shell where the movable die is arranged and at the orifice of the barrel cavity, an upper mounting ring is provided. The adjusting member at one end of the mold shell where the movable die is arranged is arranged on the upper mounting ring. And, the interval between the upper mounting ring and the cushion block seat is greater than the axial length of the adjusting bushing.

3. The cold heading die with zero clearance according to claim 2, wherein, The movable die is a stepped shaft. The large head end of the movable die is located in the barrel cavity. The upper mounting ring is sleeved on the small head end of the movable die. And, the small head end of the movable die extends outside the upper mounting ring.

4. The cold heading die with zero clearance according to claim 3, characterized in that, The barrel cavity is a stepped hole. The cross-section of the end of the barrel cavity where the cushion block seat is arranged is larger than the cross-section of the end where the movable die is arranged. And, the large head end of the conically arranged section of the barrel cavity is the end close to the cushion block seat.

5. The cold heading die with zero clearance according to claim 4, characterized in that, One end of the cushion block seat abuts against the internal step of the inner barrel cavity.

6. The cold heading die with zero clearance according to claim 2, characterized in that, The adjusting member is a setscrew. The adjusting members are respectively threadedly connected to the upper mounting ring and the cushion block seat.

7. The cold heading die with zero clearance according to claim 6, characterized in that, Each adjusting member includes a plurality of setscrews. The plurality of setscrews in each adjusting member are arranged in a circular array with the axis of the adjusting bushing as the center.

8. The cold heading die with zero clearance according to claim 1, characterized in that, An oil filling hole penetrating the side wall is opened on the outer side wall of the mold shell. The oil filling hole communicates with the section of the barrel cavity where the steel ball bushing and the adjusting bushing are installed.

9. The cold heading die with zero clearance according to claim 1, characterized in that It further includes a pre-fixing assembly. The pre-fixing assembly is installed on the mold shell. The pre-fixing assembly includes a limit pin and a pressing sleeve. A limit hole is opened on the outer side wall of the mold shell and at the end of the adjusting bushing close to the cushion block seat. The limit pin is slidably arranged in the limit hole and one end abuts against the outer side wall of the adjusting bushing. At the same time, the other end of the limit pin extends outside the mold shell. The pressing sleeve is coaxially sleeved outside the mold shell and moves axially along the adjusting bushing. The inner cavity of one end of the pressing sleeve is arranged in a conical shape. The end of the limit pin extending outside the mold shell abuts against the conical surface of the inner cavity of the pressing sleeve.

10. The cold heading die with zero clearance according to claim 9, characterized in that A protruding adjusting ring is provided on the outer side wall of the mold shell. Adjusting external threads are arranged axially along the adjusting bushing on the adjusting ring. Adjusting internal threads are arranged on the inner wall of the inner cavity of the pressing sleeve and at the end away from the conical arrangement. The pressing sleeve is in threaded cooperation with the adjusting ring. At the same time, a plurality of operating planes are distributed along the circumference of the outer side wall of the pressing sleeve.

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