Cold extrusion wheel hub primary forming device and primary forming method

Abstract

The invention provides a cold extrusion wheel hub initial forming device and initial forming method, which relate to the technical field of wheel hub processing, and solve the technical problem that two sets of molds are required for wheel hub molding in the prior art, resulting in high production cost and low production efficiency; a cold extrusion wheel hub initial forming device comprises an upper mold, a lower mold, a side mold, a cushion block, a first driving component and a fourth driving component, the bottom end of the upper mold is provided with a first molding surface, the lower mold is connected to a through hole in the middle of the side mold, the top end of the lower mold is provided with a second molding surface, the inner wall of the through hole is provided with a third molding surface, the fourth driving component drives the cushion block to slide in a horizontal direction, the first driving component is connected to the upper mold, and when the molds are closed, the first molding surface, the second molding surface and the third molding surface are combined to form a first molding cavity, the outer peripheral wall of the lower mold is provided with an annular groove along the circumferential direction to form a second molding cavity, and the projection area of ​​the first molding surface is larger than that of the second molding surface; it also includes a cold extrusion wheel hub initial forming method, which uses the above-mentioned cold extrusion wheel hub initial forming device.

Description

Technical Field

[0001] The invention relates to the technical field of wheel hub processing, in particular to a cold extrusion wheel hub initial forming device and initial forming method. Background Art

[0002] Hydraulic devices are mainly used for press forming of metal parts. Taking the hydraulic device used for wheel hub processing as an example, it includes an upper beam plate, an upper die, a lower die and a lower beam plate from top to bottom. The upper die is installed at the bottom of the upper beam plate, and the lower die is fixed on the lower beam plate. An oil cylinder is arranged in the upper beam plate to drive the upper die to move in the vertical direction and to close or open the die with the lower die. There is a cavity for forming the wheel hub between the upper die and the lower die. The raw material of the wheel hub is a cylindrical metal block. The raw material is placed on the lower die. During the closing process of the upper die and the lower die, the raw material is cold extruded. After being compressed, the raw material is deformed and formed into a wheel hub.

[0003] The wheel hub includes a rim and spokes. When processing the wheel hub, the traditional hydraulic device has a thinner rim and requires greater pressure. Since the spokes and rim are different in shape, structure, wall thickness, etc., the pressures required for the two during molding are also different. Usually, a wheel hub blank with a rim is molded with a high pressure first, and then a finished wheel hub with spokes and a rim is molded with a secondary molding. Therefore, the process requires two hydraulic equipment with different pressure values ​​and two different sets of molds. This leads to the following technical problems in the traditional hydraulic process: 1. Since different parts of the wheel hub require different pressures, the processing of one product requires two equipment and two sets of molds, the investment cost is high, and the cost is difficult to be effectively controlled, which is not conducive to long-term production and operation; 2. Between the initial molding and the secondary molding, the product needs to be switched to different equipment and molds for processing. This process is relatively cumbersome and reduces the production efficiency of the wheel hub. Summary of the invention

[0004] In view of the shortcomings of the prior art, the first object of the present invention is to provide a cold extrusion hub primary forming device to solve the technical problem that the hub forming in the prior art requires two sets of molds and two sets of equipment, resulting in high production costs and low production efficiency.

[0005] To solve the above technical problems, the present invention provides a cold extrusion hub initial forming device, including an upper die, a lower die, a side die, a cushion block, a first driving assembly and a fourth driving assembly, wherein a first molding surface is provided at the bottom end of the upper die, a through hole is provided in the middle of the side die, the lower die is connected in the through hole, a second molding surface is provided at the top end of the lower die, and a third molding surface is provided on the inner wall of the through hole, the upper die and the side die can both move back and forth vertically, the fourth driving assembly drives the cushion block to slide in the horizontal direction and makes the cushion block located below the side die and abut against the bottom end of the side die, the first driving assembly is connected to the upper die and drives the upper die to move vertically so that the upper die is molded with the lower die and the side die, when the upper die is molded with the lower die and the side die, the first molding surface, the second molding surface and the third molding surface are combined to form a first molding cavity, the outer peripheral wall of the lower die is provided with an annular groove along the circumferential direction to form a second molding cavity, the upper end of the second molding cavity is connected with the first molding cavity, and the projection area of ​​the first molding surface on the horizontal plane is greater than the projection area of ​​the second molding surface on the horizontal plane.

[0006] After adopting the above structure, the cold extrusion wheel hub initial forming device of the present invention has the following advantages: in the initial forming process of the wheel hub, the raw material is placed on the lower die. In the first forming step, the first driving assembly drives the upper die to descend so that the upper die, the lower die and the side die are molded together to form the raw material into the middle spoke of the wheel hub. In this process, the cushion block prevents the side die from moving downward, ensuring that the first molding surface, the second molding surface and the third molding surface form a complete first molding cavity that meets the final shape requirements of the wheel hub; in the second forming step, the first driving assembly continues to drive the upper die to descend. At this time, the cushion block leaves the bottom of the side die, and the downward pressure of the upper die is transmitted to the side die through the wheel hub to be formed. The side die descends synchronously with the upper die. In this forming step, since the projected area of ​​the first molding surface is larger than that of the second molding surface, the unit area pressure of the second molding surface on the wheel hub to be formed is greater. Therefore, under the same mold closing pressure, the unit area pressure on the lower end of the wheel hub to be formed is greater, which prompts the wheel hub to be formed to further deform and form the rim part in the second molding cavity, thereby forming the wheel hub in a set of molds, reducing production costs and improving production efficiency.

[0007] As an improvement, the present invention also includes a second drive assembly located below the side mold, which is used to drive the side mold to move vertically. With this structure, when the side mold descends with the upper mold, the second drive assembly maintains the pressure of the side mold, further ensuring that the side mold descends synchronously with the upper mold, preventing the side mold from descending too quickly and affecting the forming of the wheel hub.

[0008] As an improvement, the present invention also includes a third driving component, and a push rod is vertically movably connected in the lower mold. The third driving component is connected to the push rod and drives the push rod to move vertically so that the upper end of the push rod extends into the first molding cavity. With this structure, after the wheel hub is processed and formed, the third driving component drives the push rod to eject the wheel hub.

[0009] As an improvement, the upper end of the ejector pin is located in the first molding cavity, and a fourth molding surface is provided on the upper end surface of the ejector pin. With this structure, the wheel hub is molded together with the ejector pin, and the wheel hub is directly ejected after molding, which has a simple structure.

[0010] As an improvement, the second molding surface includes a plane segment, an arc segment and a conical segment from the inside to the outside, the plane segment is connected to the conical segment through the arc segment, and the ejector rod passes through the second molding surface through the center of the plane segment.

[0011] As an improvement, the third molding surface is located in the middle of the inner wall of the through hole and divides the through hole into an upper hole and a lower hole. The inner diameter of the upper hole is larger than that of the lower hole. When the upper mold is combined with the lower mold and the side mold, the upper mold is located in the upper hole and the lower mold is located in the lower hole. This structure is adopted to adapt to the structure in which the projection area of ​​the first molding surface in the horizontal direction is larger than that of the second molding surface, and the third molding surface is used as a transition part between the upper hole and the lower hole and is only used to mold the outer ring part of the lower end face of the wheel hub. Therefore, when the upper mold continues to descend, the upper mold drives the side mold to descend synchronously through the wheel hub to be molded and the third molding surface, and the wheel hub at the third molding surface maintains its original shape.

[0012] As an improvement, there are two pads and they are respectively arranged on the left and right sides of the lower end of the side mold; with this structure, the two pads can provide stable support for the side mold and can be easily separated from the lower end of the side mold.

[0013] As an improvement, the first molding surface includes a plurality of protrusions protruding downward.

[0014] The second object of the present invention is to provide a cold extrusion wheel hub initial forming method, using the above-mentioned cold extrusion wheel hub initial forming device, comprising the following steps:

[0015] S1, the first driving assembly drives the upper mold to press down and close the mold with the lower mold and the side mold. At this time, the cushion block is located under the side mold to make the side mold stationary;

[0016] S2, the fourth driving assembly drives the cushion block to leave the bottom of the side mold, the first driving assembly drives the upper mold and the side mold to move downward synchronously, and the second driving assembly provides an upward supporting force to the bottom end of the side mold and descends synchronously with the side mold;

[0017] S3. After the mold is opened, the third driving assembly drives the ejector rod to eject the initially formed wheel hub.

[0018] After adopting the above manner, the cold extrusion wheel hub initial forming method of the present invention has the following advantages: in the initial forming process of the wheel hub, the raw material is placed on the lower die. In the first forming step, the first driving assembly drives the upper die to descend so that the upper die, the lower die and the side die are molded together to form the raw material into the middle spoke of the wheel hub. In this process, the cushion block prevents the side die from moving downward, ensuring that the first molding surface, the second molding surface and the third molding surface form a complete first molding cavity that meets the final shape requirements of the wheel hub; in the second forming step, the first driving assembly continues to drive the upper die to descend. At this time, the cushion block leaves the bottom of the side die, and the downward pressure of the upper die is transmitted to the side die through the wheel hub to be formed. The side die descends synchronously with the upper die. In this forming step, since the projected area of ​​the first molding surface is larger than that of the second molding surface, the unit area pressure of the second molding surface on the wheel hub to be formed is greater. Therefore, under the same mold closing pressure, the unit area pressure on the lower end of the wheel hub to be formed is greater, which prompts the wheel hub to be formed to further deform and form the rim part in the second molding cavity, thereby forming the wheel hub in a set of molds, reducing production costs and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure before mold closing of the present invention.

[0020] Figure 2 It is a schematic diagram of the structure during the first step of molding of the present invention.

[0021] Figure 3 It is a schematic diagram of the structure during the second step of molding of the present invention.

[0022] Figure 4 It is a schematic diagram of the structure after the mold is opened in the present invention.

[0023] Figure 5 It is a front schematic diagram of the spoke in the present invention.

[0024] Figure numerals: 1. upper mold; 2. lower mold; 3. side mold; 4. first molding surface; 41. protrusion; 5. through hole; 51. upper hole; 52. lower hole; 6. second molding surface; 61. plane segment; 62. arc segment; 63. conical segment; 7. third molding surface; 8. push rod; 9. fourth molding surface; 10. second molding cavity; 11. first molding cavity; 12. spoke; 13. pad; 14. second drive assembly. DETAILED DESCRIPTION

[0025] The cold extrusion hub initial forming device and initial forming method of the present invention are described in detail below with reference to the accompanying drawings.

[0026] like Figures 1 to 4As shown, a cold extrusion wheel hub initial forming device includes an upper die 1, a lower die 2, a side die 3, a pad 13, a first drive assembly and a fourth drive assembly. The bottom end of the upper die 1 is provided with a first forming surface 4, and the first forming surface 4 includes a plurality of protrusions 41 protruding downward to match the shape of the wheel hub. Figure 5 The spoke 12 structure shown in the figure; a through hole 5 is provided in the middle of the side mold 3, the lower mold 2 is connected in the through hole 5, and a second molding surface 6 is provided at the top of the lower mold 2. The second molding surface 6 includes a plane segment 61, an arc segment 62 and a conical segment 63 from the inside to the outside, and the plane segment 61 is connected to the conical segment 63 through the arc segment 62, wherein the arc segment 62 is an arc that bulges upward obliquely, the plane segment 61 is the lowest end of the second molding surface 6, and the conical segment 63 is the highest end. The second molding surface 6 also matches the shape of the hub, and the details are not repeated here.

[0027] like Figure 1 As shown, the inner wall of the through hole 5 is provided with a third molding surface 7, the third molding surface 7 is located in the middle of the inner wall of the through hole 5 and divides the through hole 5 into an upper hole 51 and a lower hole 52, the inner diameter of the upper hole 51 is larger than the inner diameter of the lower hole 52, wherein the third molding surface 7 is a concave surface and is only used to mold the outer ring part of the lower end surface of the wheel hub; the upper mold 1 and the side mold 3 can both move back and forth vertically, the fourth driving component drives the cushion block 13 to slide in the horizontal direction and makes the cushion block 13 located below the side mold 3 and abuts against the bottom end of the side mold 3, the first driving component is connected to the upper mold 1 and drives the upper mold 1 to move vertically so that the upper mold 1 is molded with the lower mold 2 and the side mold 3, when the upper mold 1 is molded with the lower mold 2 and the side mold 3, the first molding surface 4, the second molding surface 6 and the third molding surface 7 are surrounded to form a first molding cavity 11, and the upper mold 1 is located in the upper hole 51, and the lower mold 2 is located in the lower hole 52. The outer wall of the lower mold 2 is provided with an annular groove along the circumferential direction to form a second molding cavity 10. The upper end of the second molding cavity 10 is connected to the first molding cavity 11. The projection area of ​​the first molding surface 4 on the horizontal plane is larger than the projection area of ​​the second molding surface 6 on the horizontal plane.

[0028] like Figure 3 As shown, the present invention also includes a second drive assembly 14 located below the side mold 3. The second drive assembly 14 is used to drive the side mold 3 to move vertically. In this embodiment, the second drive assembly 14 is an annular push rod hydraulic cylinder. The specific structure is the prior art and will not be repeated here. The second drive assembly 14 is installed on the lower beam plate below the lower mold 2.

[0029] The present invention also includes a third drive assembly, and the first drive assembly, the third drive assembly and the fourth drive assembly are all hydraulic cylinders, such as Figures 1 to 4As shown, a push rod 8 is vertically movably connected inside the lower mold 2, and a third driving assembly is connected to the push rod 8 and drives the push rod 8 to move vertically so that the upper end of the push rod 8 extends into the first molding cavity 11. The upper end of the push rod 8 is located in the first molding cavity 11, and a fourth molding surface 9 is provided on the upper end surface of the push rod 8, that is, the fourth molding surface 9 and the second molding surface 6 jointly mold the lower part of the hub, and the push rod 8 passes through the second molding surface 6 through the center of the plane section 61.

[0030] like Figures 1 to 3 As shown, there are two cushion blocks 13 which are respectively arranged on the left and right sides of the lower end of the side mold 3, and the two cushion blocks 13 can be horizontally driven by two fourth driving components respectively.

[0031] The present invention also relates to a cold extrusion wheel hub initial forming method, using the above-mentioned cold extrusion wheel hub initial forming device, comprising the following steps:

[0032] S1, the first driving assembly drives the upper mold 1 to press down and close the mold with the lower mold 2 and the side mold 3. At this time, the cushion block 13 is located below the side mold 3 to make the side mold 3 stationary. In this step, the mold is formed as shown in FIG. Figure 2 The hub shape is shown in shaded area;

[0033] S2, the fourth driving assembly drives the cushion block 13 to leave the bottom of the side mold 3, the first driving assembly drives the upper mold 1 and the side mold 3 to move downward synchronously, the second driving assembly 14 provides an upward support force to the bottom end of the side mold 3 and descends synchronously with the side mold 3. Specifically, the second driving assembly 14 retracts its annular push rod to the same length according to the extended length of the piston rod of the first driving assembly. In this step, a molded product such as Figure 3 The hub shape shown in the shaded portion is the final shape of the hub after initial forming;

[0034] S3. Finally, after the mold is opened, the third driving assembly drives the ejector rod 8 to eject the initially formed wheel hub.

[0035] During the initial forming process of the wheel hub, the raw material is placed on the lower mold 2, and the various structural positions before the mold is closed are as follows Figure 1 As shown; in the first step of molding, the first drive assembly drives the upper mold 1 to descend so that the upper mold 1 is molded with the lower mold 2 and the side mold 3 to mold the raw material into the middle spoke 12 of the hub, as shown Figure 2As shown, during this process, the cushion block 13 prevents the side mold 3 from moving downward, ensuring that the first molding surface 4, the second molding surface 6 and the third molding surface 7 form a complete first molding cavity 11 that meets the final shape requirements of the wheel hub; during the second step of molding, the first driving assembly continues to drive the upper mold 1 to descend, at this time the cushion block 13 leaves the side mold 3, and the downward pressure of the upper mold 1 is transmitted to the side mold 3 through the wheel hub to be molded and the third molding surface 7, driving the side mold 3 to descend synchronously, and the wheel hub at the third molding surface 7 maintains its original shape. During this step of molding, since the projected area of ​​the first molding surface 4 is larger than that of the second molding surface 6, the unit area pressure of the second molding surface 6 on the wheel hub to be molded is greater. Therefore, under the same mold clamping pressure, the unit area pressure on the lower end of the wheel hub to be molded is greater, prompting the wheel hub to be molded to further deform and form a rim part in the second molding cavity 10, as shown in FIG. Figure 3 As shown in FIG. 1 , the wheel hub is formed in one set of molds, which reduces production costs and improves production efficiency. Finally, the upper mold 1 moves upward, and the ejector rod 8 ejects the formed wheel hub. Figure 4 shown.

[0036] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned one embodiment, and all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. The above cold extrusion molding device and molding method are also applicable to heating extrusion and hot extrusion, so the application of the present invention to these fields also falls within the scope of protection of the present invention.

Claims

1. A cold extrusion wheel hub primary forming device, characterized in that: The invention comprises an upper mold (1), a lower mold (2), a side mold (3), a cushion block (13), a first driving component and a fourth driving component, wherein the bottom end of the upper mold (1) is provided with a first molding surface (4), the middle part of the side mold (3) is provided with a through hole (5), the lower mold (2) is connected to the through hole (5), the top end of the lower mold (2) is provided with a second molding surface (6), the inner wall of the through hole (5) is provided with a third molding surface (7), the upper mold (1) and the side mold (3) are both capable of vertical reciprocating movement, the fourth driving component drives the cushion block (13) to slide in a horizontal direction and makes the cushion block (13) located below the side mold (3) and abutting against the bottom end of the side mold (3), the first driving component The component is connected to the upper mold (1) and drives the upper mold (1) to move vertically so that the upper mold (1) is molded with the lower mold (2) and the side mold (3). When the upper mold (1) is molded with the lower mold (2) and the side mold (3), the first molding surface (4), the second molding surface (6) and the third molding surface (7) are surrounded to form a first molding cavity (11). The outer peripheral wall of the lower mold (2) is provided with an annular groove along the circumference to form a second molding cavity (10). The upper end of the second molding cavity (10) is connected to the first molding cavity (11). The projection area of ​​the first molding surface (4) on the horizontal plane is larger than the projection area of ​​the second molding surface (6) on the horizontal plane.

2. The cold extrusion hub primary forming device according to claim 1, characterized in that: It also comprises a second drive assembly (14) located below the side mould (3), the second drive assembly (14) being used to drive the side mould (3) to move vertically.

3. The cold extrusion hub primary forming device according to claim 1, characterized in that: It also comprises a third driving assembly, wherein a push rod (8) is vertically movably connected inside the lower mold (2), and the third driving assembly is connected to the push rod (8) and drives the push rod (8) to move vertically so that the upper end of the push rod (8) extends into the first molding cavity (11).

4. The cold extrusion hub primary forming device according to claim 3, characterized in that: The upper end of the push rod (8) is located in the first molding cavity (11), and the upper end surface of the push rod (8) is provided with a fourth molding surface (9).

5. The cold extrusion hub primary forming device according to claim 4, characterized in that: The second molding surface (6) comprises, from the inside to the outside, a plane segment (61), an arc segment (62) and a conical segment (63); the plane segment (61) is connected to the conical segment (63) via the arc segment (62); and the ejector rod (8) passes through the center of the plane segment (61) and out of the second molding surface (6).

6. The cold extrusion hub primary forming device according to claim 1, characterized in that: The third molding surface (7) is located in the middle of the inner wall of the through hole (5) and divides the through hole (5) into an upper hole (51) and a lower hole (52); the inner diameter of the upper hole (51) is larger than the inner diameter of the lower hole (52); when the upper mold (1) is molded with the lower mold (2) and the side mold (3), the upper mold (1) is located in the upper hole (51) and the lower mold (2) is located in the lower hole (52).

7. The cold extrusion hub primary forming device according to claim 1, characterized in that: There are two cushion blocks (13) which are respectively arranged on the left and right sides of the lower end of the side mold (3).

8. The cold extrusion hub primary forming device according to claim 1, characterized in that: The first molding surface (4) comprises a plurality of protrusions (41) protruding downwards.

9. A cold extrusion wheel hub primary forming method, characterized in that: The cold extrusion hub primary forming device according to any one of claims 1 to 8 comprises the following steps: S1, the first driving component drives the upper mold (1) to press down to close the mold with the lower mold (2) and the side mold (3), and at this time, the cushion block (13) is located below the side mold (3) so that the side mold (3) is stationary; S2, the fourth driving component drives the cushion block (13) to leave the bottom of the side mold (3), the first driving component drives the upper mold (1) and the side mold (3) to move downward synchronously, and the second driving component (14) provides an upward supporting force to the bottom end of the side mold (3) and descends synchronously with the side mold (3); S3, after the mold is opened, the third driving assembly drives the ejector rod (8) to eject the initially formed wheel hub.

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