Die structure suitable for forming part with wall thickness smaller than or equal to 0.5 mm

Abstract

The invention relates to the technical field of cold heading, in particular to a die structure suitable for forming a part with the wall thickness smaller than or equal to 0.5 mm. The die structure comprises a main die and an auxiliary die. A push pipe and an annular groove are arranged in the auxiliary mold; the auxiliary die is of a cylindrical structure, and the push pipe is movably arranged in the auxiliary die in the axis direction of the auxiliary die and can stretch out of the end, facing the main die, of the auxiliary die. The annular groove is formed in the end, facing the main die, of the ejector sleeve in the axis direction of the ejector sleeve, the width of the annular groove is larger than or equal to 0.5 mm, and when the ejector sleeve stretches out, the bottom of the annular groove makes direct contact with the end of a machined part. The bearing strength of the push pipe is effectively improved, the phenomenon that when the push pipe pushes a thin-wall part with the wall thickness smaller than or equal to 0.5 mm for a long time, the end of the push pipe is bent or deformed is avoided, the service life of the push pipe is prolonged, cold heading one-time forming of the part is achieved, the machining cost is reduced, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cold heading, in particular to a mold structure suitable for forming a part with a wall thickness of less than or equal to 0.5 mm. BACKGROUND

[0002] With the upgrading of manufacturing industry, the market requires higher production efficiency and cost control of parts. Traditional machining is gradually limited in mass production due to long cycle, low material utilization rate and limited production capacity. Cold heading process has become the first choice for more part processing due to its high material utilization rate, fast production efficiency and low cost, gradually replacing machining and widely used in automobile, machinery and other fields.

[0003] At present, cold heading process can form most parts with thick wall thickness. As long as the wall thickness is greater than 0.5 mm, the main forming can be completed by one-time extrusion of the mold, and the part precision and smoothness are high, and only a small amount of auxiliary processing is required subsequently.

[0004] However, when cold heading processes thin-walled parts with a wall thickness of less than or equal to 0.5 mm, it still needs to rely on machining. The core problem lies in the demolding mechanism of cold heading: the part needs to be pushed out by the push tube after forming, and the inner wall thickness of the push tube needs to be basically the same as the product wall thickness to ensure uniform pushing force. When the product wall thickness is less than or equal to 0.5 mm, the push tube will also be too thin in thickness, resulting in insufficient strength. Not only is it difficult to withstand the axial pushing force and radial extrusion force during demolding, but it is also prone to fatigue damage at stress concentration points such as the end, and it is also prone to bending and vibration due to poor rigidity, further aggravating uneven stress. After a period of use, the end of the push tube may curl or deform as a whole, affecting demolding, and in severe cases, the tube wall may tear, causing the push tube to be scrapped, and accidents such as product jamming and mold damage may also occur. SUMMARY

[0005] In view of the above problems, a mold structure suitable for forming a part with a wall thickness of less than or equal to 0.5 mm is provided. A push tube and an annular groove are arranged in the sub-mold, and the annular groove has a groove width of greater than or equal to 0.5 mm, so that the tube wall thickness of the push tube is much greater than the wall thickness of the workpiece (at least 2 mm to 3 mm), effectively improving the pressure-bearing strength of the push tube.

[0006] To solve the problems in the prior art, the present application provides a mold structure suitable for forming a part with a wall thickness of less than or equal to 0.5 mm, comprising a main mold and a sub-mold. A push tube and an annular groove are arranged in the sub-mold. The sub-mold is in a cylindrical structure, and the push tube is arranged in the sub-mold along the axial direction of the sub-mold and can extend out of the end of the sub-mold towards the main mold. The annular groove is arranged on one end of the push tube towards the main mold along the axial direction of the push tube, and the groove width of the annular groove is greater than or equal to 0.5 mm. When the push tube extends out, the bottom of the annular groove is in contact with the end of the workpiece.

[0007] Preferably, a driving rod is arranged in the sub-mold. The driving rod is arranged in the sub-mold along the axial direction of the sub-mold, and an extension is fixedly arranged on one end of the driving rod facing the main mold along the axial direction of the driving rod, the extension extending into the push tube and moving synchronously with the push tube.

[0008] Preferably, the push tube is detachably arranged on the extension of the driving rod.

[0009] Preferably, a latch is arranged on the push tube along the radial direction of the push tube, and the latch penetrates the push tube and the extension of the driving rod in sequence along the vertical direction.

[0010] Preferably, an abutting groove is formed on the inner wall of the push tube along the extension direction of the push tube, and a protrusion is fixedly arranged on the extension of the driving rod, the protrusion being in sliding cooperation with the abutting groove, and when the push tube moves the workpiece, the end of the protrusion facing the main mold abuts against the end of the abutting groove facing the main mold.

[0011] Preferably, a reserved groove is formed through the extension of the driving rod, the length direction of the reserved groove being the same as the extension direction of the extension, and the latch extends into the reserved groove and is in sliding cooperation with the reserved groove.

[0012] Preferably, a limiting sleeve is fixedly arranged in the sub-mold along the axial direction of the sub-mold, the driving rod is slidingly arranged in the limiting sleeve along the extension direction of the limiting sleeve, and a gap is formed between the end of the driving rod and the end of the limiting sleeve, a spring is arranged in the gap, and the two ends of the spring are fixedly connected with the end of the driving rod and the end of the limiting sleeve, respectively.

[0013] Preferably, the sub-mold comprises a first mold body and a second mold body arranged horizontally, the push tube is located in the first mold body, and one end of the first mold body is threadedly cooperated with one end of the second mold body.

[0014] Preferably, the limiting sleeve is fixedly arranged in the interior of the first mold body.

[0015] Preferably, a wear-resistant coating is coated on the bottom end face of the annular groove.

[0016] The beneficial effects of the present application compared with the prior art are: 1. By arranging the push tube and the annular groove in the sub-mold, and the groove width of the annular groove being greater than or equal to 0.5 mm, the thickness of the push tube wall is much greater than the wall thickness of the workpiece, the pressure bearing strength of the push tube is effectively improved, the end bending or deformation of the push tube when pushing the thin-walled part with a wall thickness ≤0.5 mm for a long time is avoided, the service life of the push tube is prolonged, the cold upsetting one-step forming of the part is realized, the processing cost is reduced, and the production efficiency is improved.

[0017] 2. By detachably arranging the push tube on the extension of the driving rod, and adopting the cooperation structure of the latch, the abutting groove and the protrusion, and the design of the reserved groove, not only the replacement and maintenance of the push tube are facilitated, but also the reverse force of the push tube on the latch is avoided, the load and the deformation rate of the latch are greatly reduced, the problem that the latch is difficult to detach after long-term use is solved, and stable operation of the pushing mechanism is ensured.

[0018] 3. By arranging the limiting sleeve with spring in the secondary mold, designing the secondary mold as a split structure, and coating the wear-resistant coating on the bottom of the annular groove, the buffer protection of the driving rod is realized, the secondary mold maintenance and spring replacement are facilitated, and the wear of the annular groove and the workpiece when in contact is reduced, the push tube and the parts are protected, and the maintenance efficiency and overall durability of the mold structure are improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a three-dimensional schematic view of a mold structure suitable for forming a part with a wall thickness of less than or equal to 0.5mm.

[0020] Figure 2 is a sectional three-dimensional schematic view of a mold structure suitable for forming a part with a wall thickness of less than or equal to 0.5mm.

[0021] Figure 3 is a sectional three-dimensional schematic view of a mold structure suitable for forming a part with a wall thickness of less than or equal to 0.5mm. Figure 2 is a sectional three-dimensional schematic view of a mold structure suitable for forming a part with a wall thickness of less than or equal to 0.5mm.

[0022] Figure 4 is a three-dimensional schematic view of a mold structure suitable for forming a part with a wall thickness of less than or equal to 0.5mm after removing the first mold body.

[0023] Figure 5 is a sectional three-dimensional schematic view of a mold structure suitable for forming a part with a wall thickness of less than or equal to 0.5mm after removing the first mold body.

[0024] Figure 6 is a sectional three-dimensional schematic view of a mold structure suitable for forming a part with a wall thickness of less than or equal to 0.5mm. Figure 5 is a sectional three-dimensional schematic view of a mold structure suitable for forming a part with a wall thickness of less than or equal to 0.5mm.

[0025] Figure 7 is a three-dimensional schematic view of a driving rod in a mold structure suitable for forming a part with a wall thickness of less than or equal to 0.5mm.

[0026] The figure marks are: 1, sub-mold; 11, push tube; 111, annular groove; 112, latch; 113, abutting groove; 114, protruding block; 12, driving rod; 121, extension; 122, reserved groove; 13, limiting sleeve; 131, spring; 14, first mold body; 15, second mold body; 2, machined part. DETAILED DESCRIPTION

[0027] In order to further understand the features, technical means and specific purposes and functions achieved by the present application, the present application will be described in further detail below with reference to the drawings and specific embodiments.

[0028] Reference Figures 1-4 A mold structure suitable for forming parts with a wall thickness of less than or equal to 0.5 mm, comprising a main mold and a sub-mold 1; A push tube 11 and an annular groove 111 are arranged in the sub-mold 1; The sub-mold 1 is in a cylindrical structure, and the push tube 11 is arranged in the sub-mold 1 along the axial direction of the sub-mold 1 and can extend from the end of the sub-mold 1 towards the main mold; The annular groove 111 is arranged on the end of the push tube 11 towards the main mold along the axial direction of the push tube 11, and the groove width of the annular groove 111 is greater than or equal to 0.5 mm. When the push tube 11 extends, the bottom of the annular groove 111 is in contact with the end of the machined part 2.

[0029] In order to improve production efficiency, many machined parts 2 are processed by cold heading method, but after cold heading is completed, the machined part 2 that has completed cold heading needs to be ejected, otherwise the machined part 2 cannot be discharged by itself. The cold heading process is mainly completed by the main mold and the sub-mold 1. The main mold moves, the sub-mold 1 is static, and the main mold and the sub-mold 1 form a forming cavity when they are closed. When the cold heading is completed, the machined part 2 remains in the sub-mold 1, and due to the influence of the pressure during cold heading, the machined part 2 that is cold headed is tightly attached to the sub-mold 1. When the machined part 2 is pushed out of the sub-mold 1, a certain pushing force needs to be applied to smoothly push out the machined part 2. However, part of the machined part 2 to be processed in the present application is a thin-walled tubular structure, and the thin-walled tubular structure is processed into a shape and then stuck in the sub-mold 1. Therefore, the pushing-out mechanism is still needed to push out the machined part 2. The existing solution is to use the push tube 11 to push out the machined part 2. However, since the wall thickness of the present machined part 2 is less than or equal to 0.5 mm, the wall thickness is thin, and in order to ensure the consistency of the wall thickness of the push tube 11 and the machined part 2, the wall thickness of the push tube 11 is also thin. The bearing strength of the push tube 11 is limited, and the pushing force required for the push tube 11 to push the machined part 2 out of the sub-mold 1 will act on the push tube 11 in the opposite direction, causing the end of the push tube 11 to bend or deform after long-term use.

[0030] In order to avoid the above situation, the existing mold structure is optimized and designed, so that the mold structure of the application can complete the forming of the machining part 2 with a wall thickness of less than or equal to 0.5 mm, and after long-term use, the push tube 11 will not be curled or deformed. The working process of the application is as follows: Before processing, the machining part 2 to be processed is placed between the main mold and the auxiliary mold 1, at this time the main mold and the auxiliary mold 1 are in a separated state, then the main mold moves towards the auxiliary mold 1 and clamps the machining part 2, as the main mold continues to press, the machining part 2 also gradually deforms, when the main mold and the auxiliary mold 1 are closed, the machining part 2 is cold-formed. Then the main mold and the auxiliary mold 1 are separated, and the machining part 2 remains in the auxiliary mold 1, at this time one end of the machining part 2 is in a non-contact state with the annular groove 111 on the push tube 11. When it is needed to push out the machining part 2, the push tube 11 moves along the axis direction of the auxiliary mold 1 towards the end of the machining part 2 under the action of hydraulic pressure, when the bottom of the annular groove 111 contacts the end of the machining part 2, the machining part 2 can be pushed by the push tube 11. Since the groove width of the annular groove 111 is greater than or equal to 0.5 mm, and the annular groove 111 is provided at the end of the push tube 11, the wall thickness of the push tube 11 is much greater than 0.5 mm, and the wall thickness of the push tube 11 is at least 2 mm to 3 mm. Therefore, when the machining part 2 is pushed to move by the push tube 11, because the wall thickness of the push tube 11 is much greater than the wall thickness of the machining part 2, the end of the push tube 11 is not easy to curl or deform when pushing the machining part 2 to slide out of the auxiliary mold 1, thereby prolonging the service life of the push tube 11. Thus, the machining part is cold-formed once, greatly reducing the cost of part processing and improving the production efficiency of the part.

[0031] Referring to Figure 5 and Figure 7 : A driving rod 12 is further provided in the auxiliary mold 1; The driving rod 12 is movably arranged in the auxiliary mold 1 along the axis direction of the auxiliary mold 1, and an extension 121 is fixedly arranged on one end of the driving rod 12 facing the main mold along the axis direction of the driving rod 12, the extension 121 extends into the push tube 11, and the extension 121 moves synchronously with the push tube 11.

[0032] The driving rod 12 is driven by hydraulic pressure, and the driving rod 12 drives the push tube 11 to move synchronously through the extension 121.

[0033] Referring to Figures 1-7 : The push tube 11 is detachably arranged on the extension 121 of the driving rod 12.

[0034] Although the thickness of the push tube 11 is greater than the wall thickness of the machining part 2, the bottom end face of the annular groove 111 will be worn out after long-term pushing of the machining part 2, therefore, the push tube 11 is sleeved on the extension 121, which facilitates replacement of the push tube 11.

[0035] Referring toFigure 4 、 Figure 6 and Figure 7 The latch 112 is arranged on the push tube 11 in the radial direction of the push tube 11 and penetrates the push tube 11 and the extension part 121 of the driving rod 12 in sequence in the vertical direction.

[0036] The push tube 11 is fixed on the extension part 121 of the driving rod 12 through the latch 112, and when the push tube 11 needs to be replaced, the latch 112 can be pulled out.

[0037] Referring to Figure 6 and Figure 7 The abutting groove 113 is arranged on the inner wall of the push tube 11 in the extension direction of the push tube 11, and the protrusion 114 is fixedly arranged on the extension part 121 of the driving rod 12 and is in sliding cooperation with the abutting groove 113, and when the push tube 11 pushes the workpiece 2 to move, the one end of the protrusion 114 facing the main mold abuts against the one end of the abutting groove 113 facing the main mold.

[0038] Since the push tube 11 is sleeved on the extension part 121 of the driving rod 12, when the push tube 11 pushes the workpiece 2 through the annular groove 111, the reaction force acting on the push tube 11 will directly act on the latch 112, causing the latch 112 to bend after a long time, and when the push tube 11 needs to be detached from the extension part 121 of the driving rod 12, the latch 112 cannot be pulled out. In order to avoid the above situation, the abutting groove 113 is arranged on the inner wall of the push tube 11, and the protrusion 114 is arranged on the extension part 121 of the driving rod 12, so that the protrusion 114 is in sliding cooperation with the abutting groove 113, and when the push tube 11 pushes the workpiece 2, the one end of the protrusion 114 facing the main mold abuts against the one end of the abutting groove 113 facing the main mold. At this time, the protrusion 114 and the latch 112 bear force together, which reduces the load of the latch 112 and further reduces the deformation rate of the latch 112 after a long time of use.

[0039] Referring to Figure 6 and Figure 7 The reserved groove 122 is arranged on the extension part 121 of the driving rod 12 and is in sliding cooperation with the latch 112.

[0040] Before the push tube 11 contacts the workpiece 2, the latch 112 is located at the end of the reserved slot 122 close to the main mold. When the push tube 11 exerts a pushing force on the workpiece 2, the push tube 11 is subjected to the reaction force of the workpiece 2, and the push tube 11 drives the latch 112 to move slightly away from the end of the reserved slot 122 close to the main mold. In this process, the latch 112 is not subjected to any external force, and the reaction force generated when the push tube 11 pushes the workpiece 2 to move is all borne by the protrusion 114. The bending of the latch 112 under the reaction force is completely avoided. After the workpiece 2 is pushed out, when the driving rod 12 drives the push tube 11 to reset through the extension 121, with the movement of the extension 121, the latch 112 first moves towards the end of the reserved slot 122 close to the main mold. When the latch 112 reaches the end of the reserved slot 122 close to the main mold, the extension 121 drives the push tube 11 to reset together through the latch 112.

[0041] With reference to Figure 5 : The limiting sleeve 13 is fixedly arranged in the sub-mold 1 along the axial direction of the sub-mold 1. The driving rod 12 is slidingly arranged in the limiting sleeve 13 along the extension direction of the limiting sleeve 13, and there is a gap between the end of the driving rod 12 and the end of the limiting sleeve 13. The spring 131 is arranged in the gap, and the two ends of the spring 131 are fixedly connected with the end of the driving rod 12 and the end of the limiting sleeve 13 respectively.

[0042] By arranging the spring 131 in the limiting sleeve 13, the spring 131 buffers the driving rod 12.

[0043] With reference to Figure 2 : The sub-mold 1 includes the first mold body 14 and the second mold body 15 arranged horizontally. The push tube 11 is located in the first mold body 14, and one end of the first mold body 14 is threadedly connected with one end of the second mold body 15.

[0044] By arranging the sub-mold 1 in a split type, the sub-mold 1 is convenient to overhaul.

[0045] With reference to Figure 5 : The limiting sleeve 13 is fixedly arranged in the interior of the first mold body 14.

[0046] When the first mold body 14 and the second mold body 15 are disassembled, since the limiting sleeve 13 is fixedly arranged in the first mold body 14, the spring 131 in the interior of the limiting sleeve 13 can be directly replaced, without the need to disassemble the limiting sleeve 13 again, thereby improving the subsequent maintenance efficiency.

[0047] With reference to Figures 1-7 : The bottom end face of the annular groove 111 is coated with a wear-resistant coating.

[0048] The wear of the end of the workpiece 2 to the bottom end face of the annular groove 111 is reduced when the push tube 11 pushes out the workpiece 2 through the annular groove 111, and the wear-resistant coating can also reversely protect the end face of the pushed-out workpiece 2, thereby prolonging the service life of the push tube 11 and reducing the damage to the workpiece 2 when the push tube 11 pushes out the workpiece 2 through the annular groove 111.

[0049] The above embodiments only express one or several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as the limitation of the protection scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A mold structure suitable for molding parts with a wall thickness of less than or equal to 0.5 mm, comprising a main mold and a secondary mold (1); Its features are, A push tube (11) and an annular groove (111) are provided in the sub-mold (1); The sub-mold (1) has a cylindrical structure, and the push tube (11) is moved along the axial direction of the sub-mold (1) and is set in the sub-mold (1) and can extend from the end of the sub-mold (1) toward the main mold; An annular groove (111) is opened along the axial direction of the push tube (11) on the end of the push tube (11) facing the main mold. The groove width of the annular groove (111) is greater than or equal to 0.5mm. When the push tube (11) extends, the bottom of the annular groove (111) contacts the end of the workpiece (2).

2. The mold structure according to claim 1, suitable for molding parts with a wall thickness of less than or equal to 0.5 mm, is characterized in that, A drive rod (12) is also provided in the sub-mold (1); The drive rod (12) is moved along the axis of the sub-mold (1) and is disposed in the sub-mold (1). An extension (121) is fixedly disposed on the end of the drive rod (12) facing the main mold along the axis of the drive rod (12). The extension (121) extends into the push tube (11) and moves synchronously with the push tube (11).

3. The mold structure according to claim 2, suitable for molding parts with a wall thickness of less than or equal to 0.5 mm, is characterized in that, The push tube (11) is detachably mounted on the extension (121) of the drive rod (12).

4. The mold structure according to claim 3, suitable for molding parts with a wall thickness of less than or equal to 0.5 mm, is characterized in that, A pin (112) is provided on the push tube (11) along the radial direction of the push tube (11), and the pin (112) passes through the push tube (11) and the extension (121) of the drive rod (12) in the vertical direction.

5. A mold structure according to claim 4, suitable for molding parts with a wall thickness of less than or equal to 0.5 mm, characterized in that, An abutment groove (113) is provided on the inner wall of the push tube (11) along the extension direction of the push tube (11). A protrusion (114) is fixedly provided on the extension (121) of the drive rod (12). The protrusion (114) slides with the abutment groove (113). When the push tube (11) pushes the workpiece (2) to move, the end of the protrusion (114) facing the main mold abuts with the end of the abutment groove (113) facing the main mold.

6. A mold structure according to claim 5, suitable for molding parts with a wall thickness of less than or equal to 0.5 mm, characterized in that, A reserved slot (122) is provided through the extension (121) of the drive rod (12). The length direction of the reserved slot (122) is the same as the extension direction of the extension (121). The pin (112) extends into the reserved slot (122) and slides into the reserved slot (122).

7. A mold structure according to claim 2, suitable for molding parts with a wall thickness of less than or equal to 0.5 mm, characterized in that, A limiting sleeve (13) is fixedly installed in the sub-mold (1) along the axial direction of the sub-mold (1). A drive rod (12) is slidably installed in the limiting sleeve (13) along the extension direction of the limiting sleeve (13). There is a gap between the end of the drive rod (12) and the end of the limiting sleeve (13). A spring (131) is installed in the gap. The two ends of the spring (131) are fixedly connected to the end of the drive rod (12) and the end of the limiting sleeve (13), respectively.

8. A mold structure according to claim 7, suitable for molding parts with a wall thickness of less than or equal to 0.5 mm, characterized in that, The sub-mold (1) includes a first mold body (14) and a second mold body (15) arranged horizontally. The push tube (11) is located inside the first mold body (14), and one end of the first mold body (14) is threadedly engaged with one end of the second mold body (15).

9. A mold structure according to claim 8, suitable for molding parts with a wall thickness of less than or equal to 0.5 mm, characterized in that, The limiting sleeve (13) is fixedly installed inside the first mold body (14).

10. A mold structure according to claim 1, suitable for molding parts with a wall thickness of less than or equal to 0.5 mm, characterized in that, The bottom end face of the annular groove (111) is coated with a wear-resistant coating.

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