JP2006289412A - Forging device and forging method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a forging device and a forging method for a rough forging process of performing the volume distribution of a workpiece, by which device and method, dimensional defects and transportation troubles of the workpiece hardly occur in the following processes. <P>SOLUTION: The forging device comprises an upper die 2 having a die cavity having a shape corresponding to that of the workpiece after the rough forging, and a lower die 3 having no die cavity. The surface 3a of the lower die 3 facing to the upper die 2 is a flat surface and is received in the die cavity 2a of the upper die 2 at the bottom dead point of the forging. By this configuration, scales accumulated on the lower die 3 can be easily removed. Further, it is not necessary to lift the workpiece 1 in order to grip the workpiece 1 by means of a carrying jig 7 when the workpiece 1 is transferred to the next process after the rough forging process. Therefore, the dimensional defects and the transportation troubles of the workpiece 1 hardly occur in the following processes. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a forging device that is a workpiece manufacturing device and a forging method, and more particularly to a forging device and a forging method for manufacturing a hub used as an undercarriage part of an automobile.

  Generally, a hub used as an undercarriage part of an automobile is divided into an outer ring assembled on a vehicle body side suspension and an inner ring assembled on a wheel drive shaft side, and the inner and outer rings are coupled via a bearing. These inner and outer rings are generally manufactured by a forging method because high strength is required.

  As shown in FIG. 5, the forging process of the hub includes a rough ground forming process (1 process, FIG. 5 (a)) that performs volume distribution in the longitudinal direction and the width direction of the work 51 based on the finished shape, and an approximate product shape. Preliminary forming step (2 steps, FIGS. 5 (b) and (e)), finishing step (3 steps, FIGS. 5 (c) and (f)) for forming into a product shape, and piercing for punching the inner burr 52 A process (4 processes, FIG.5 (d)) and a trim process (5 processes, FIG.5 (d)) which punches the product 54 from the outer burr | flash 53 are comprised. Moreover, the molded product of each process is conveyed by the automatic conveyance apparatus to the next process. As described above, the hub is generally manufactured by a multistage forging method using automatic conveyance.

The volume distribution of the work in one process among the above processes affects the finished shape and is important for efficiently transporting the work to the next process. As a forming method for performing volume distribution of a work in one process, as shown in FIG. 6, a method of carving a shape after forming into a lower mold and pressing the upper mold into a sealed state (for example, Patent Documents) 1). In this method, the work 62 is conveyed into the lower mold 61 in which the shape after molding is engraved (FIG. 6A), the upper mold 63 is pushed in and the work 62 is compression-molded (FIG. 6B), After compression molding, the workpiece 62 is raised by the lower die knockout pin 64 provided on the lower die 61, and the workpiece 62 is gripped by the conveying jig 65 and conveyed to two steps (FIG. 6C).
JP 5-349

This method has the following problems.
(1) Since the lower die 61 has an engraved shape, the scale 66 generated at the time of molding is accumulated in the lower die 61, and the scale 66 may adhere to the workpiece 62 when the next workpiece is molded ( FIG. 6 (c)). In this case, if the molding proceeds to the final process with the scale 66 attached, the attached scale may be peeled off, resulting in a lack of thickness and a defective dimension.
(2) When the lower mold 61 has an engraved shape, a mechanism that receives the conveyed material, releases the molded workpiece 62 from the lower mold 61, and lifts the workpiece 62 to a height that can be grasped by the conveying tool 65. Is required. In general, this mechanism is performed by moving a lower knockout pin 64 provided on the lower mold up and down by a mechanical mechanism. Therefore, when an operation failure occurs in the mechanical mechanism for moving the lower knockout pin 64 up and down, a conveyance failure of the workpiece 62 occurs due to a drop of the workpiece 62, a variation in the height of the workpiece 62 after the lift, or the like. There is a case.

  As another forming method for distributing the volume of the work in one process, as shown in FIG. 7, there is a method in which the upper and lower dies 63 and 61 do not have a die engraving for restricting the diameter and are formed in an open state in the radial direction. is there. In this method, the outer dimension of the workpiece 62 after molding may not be stable, and there may be cases where the conveyance of the workpiece 62 is poor or the volume distribution varies in two or more steps.

  The present invention has been made in view of the above problems, and in a wasteland forming process for distributing the volume of a work, a forging device and a forging method in which a dimensional defect or a conveyance defect of the work is unlikely to occur in the subsequent process or later. The purpose is to provide.

  The present invention is a forging apparatus for performing a rough ground forming step of volume distribution of a workpiece among the forging steps in the multi-stage forging method, and has an upper die having a shape carved shape after the rough ground forming, and a die carving. It is characterized by comprising no lower mold.

  Further, the present invention is a forging method of a rough ground forming step for distributing the volume of a work among the forging steps in the multi-stage forging method, the step of conveying the work to a lower die having no die engraving, and the rough ground forming Lowering the upper die with the engraving of the later shape to the molding bottom dead center and forming the workpiece on the ground, raising the upper die from the molding bottom dead center, and using the upper die knockout pin provided on the upper die The method includes a step of releasing the mold from the upper mold, and a step of gripping the workpiece placed on the lower mold with a conveyance jig and conveying the workpiece to the next process.

  According to the present invention, since the lower mold does not have a mold carving, the scale accumulated on the lower mold can be easily removed. Further, when the work is transported to the next process after the rough ground forming, it is not necessary to raise the work to grip the work with the transport jig. Therefore, it is difficult for the dimension failure and the conveyance defect of the workpiece to occur in the subsequent processes.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
With reference to FIG. 1, the forging apparatus 100 which is Embodiment 1 of this invention is demonstrated. FIG. 1 is a diagram illustrating a procedure of a wasteland forming process by the forging device 100, where (a) is a diagram illustrating a state of a molding top dead center, (b) is a diagram illustrating a state of a molding bottom dead center, and (c). These are figures showing the state which conveys a workpiece | work to the following process.

  The forging device 100 performs a wasteland forming step of performing volume distribution in the longitudinal direction and the width direction of the workpiece 1 based on the finished shape among the forging steps in the multistage forging method, and is fixed to a die set (not shown). An upper mold 2 and a lower mold 3 are provided.

  The upper die 2 has a workpiece-shaped die-sculpture 2a after rough forming, and moves up and down while being guided by a support (not shown) provided in the die set. The upper die 2 is compressed from the molding top dead center shown in FIG. 1A to the molding bottom dead center shown in FIG. The upper mold 2 is provided with an upper mold knockout pin 4 that penetrates the upper mold 2 and can be moved up and down after the work 1 is formed on the rough ground.

  The lower mold 3 does not have a mold carving, and the surface 3a facing the upper mold 2 is a flat surface that fits in the mold carving 2a of the upper mold 2 in a state where the upper mold 2 is lowered to the molding bottom dead center. .

Next, a forging method in the wasteland forming process by the forging device 100 will be described.
(1) As shown in FIG. 1A, the workpiece 1 is gripped by the conveyance jig 6, and an automatic conveyance device (not shown) places the workpiece 1 on the lower mold 3.
(2) As shown in FIG. 1B, the upper mold 2 moves from the molding top dead center to the molding bottom dead center. At this time, the surface 3 a facing the upper mold 2 in the lower mold 3 is accommodated in the mold carving 2 a of the upper mold 2. In this way, the workpiece 1 is compression-molded by the engraving 2a of the upper die 2 and the surface 3a of the lower die 3, and volume distribution in the longitudinal direction and the width direction of the workpiece 1 is performed.
(3) As shown in FIG. 1C, the upper die 2 rises from the molding bottom dead center, and the upper die knockout pin 4 provided on the upper die 2 moves downward. The workpiece 1 is released from the mold engraving 2a of the upper mold 2 by being pressed by the upper mold knockout pin 4, and is placed on the surface 3a of the lower mold 3 as it is.
(4) After the upper mold 2 is raised to the top dead center of the molding, the gripping surface 1a which is the outer peripheral surface of the work 1 placed on the surface 3a of the lower mold 3 is gripped by the transport jig 7, and the automatic transport device (Not shown) conveys the workpiece 1 to the next process.
(5) After the workpiece 1 is transferred to the next process, if the scale is accumulated on the surface 3a of the lower mold 3, the scale is discharged out of the lower mold 3 by air or the like.

  As described above, according to the first embodiment, the surface 3a of the lower mold 3 that faces the upper mold 2 is formed of a flat surface without a sculpture, so that the scale is formed on the lower mold 3. Even when it is accumulated, the scale can be easily removed by air or the like. Therefore, since scale does not adhere to the work 1, dimensional defects of the work 1 are unlikely to occur in subsequent steps.

  Further, in a state where the volume of the work 1 is distributed and the upper mold 2 is raised to the top dead center, the lower mold 3 does not have a carved shape, so that the gripping surface 1a of the work 1 interferes with the lower mold 3. There is no. Therefore, when the workpiece 1 is gripped and transported to the next process, the step of releasing the workpiece 1 from the lower mold 3 and raising it is unnecessary, and the gripping surface is in a state where the workpiece 1 is placed on the lower mold 3. 1a can be gripped by the transport jig 7. Thus, since a mechanism for raising the workpiece 1 for gripping the workpiece 1 with the conveying jig 7 is not required, a conveyance defect is hardly generated when the workpiece 1 is conveyed to the next process.

  As shown in FIG. 1A, the mold carving 2a of the upper mold 2 has a predetermined inclination with respect to the vertical direction so that the opening area increases toward the opening, that is, the inner wall surface 2b of the mold carving 2a. You may comprise so that it may have angle (theta). By forming the die engraving 2a in this way, when the workpiece 1 is formed into rough ground and the workpiece 1 is released from the upper die 2, the workpiece 1 can be easily released from the die engraving 2a of the upper die 2. . Since the inner wall surface 2b of the mold carving 2a is inclined, the outer peripheral surface of the work 1 to be rough-ground formed, that is, the gripping surface 1a also has a predetermined angle with respect to the vertical direction. Therefore, it is desirable to set the inclination angle θ of the inner wall surface 2b of the die carving 2a to an angle at which the conveying jig 7 can easily grip the workpiece 1. Specifically, by setting the inclination angle θ to be greater than 0 ° and 3 ° or less, both the requirements for both the releasability and the transportability of the workpiece 1 can be satisfied.

  In the first embodiment, the lower mold 3 is not provided with the lower knockout pin. However, as shown in FIG. 2, the lower mold 3 may be provided with a lower knockout pin 21 penetrating vertically. Is possible. In this case, the lower die knockout pin 21 is lowered in a state where the upper die 2 is lowered to the molding bottom dead center, and the lower die knockout pin 21 and the surface 3a of the lower die 3 facing the upper die 2 are connected to the upper die 2. What is necessary is just to form the flat surface which fits in the mold carving 2a (FIG.2 (b)). In this aspect, when the workpiece 1 is gripped and transported to the next process, the workpiece 1 is placed on the lower die knockout pin 21 and the surface 3 a of the lower die 3 without raising the lower die knockout pin 21. In this state, the gripping surface 1a may be gripped by the conveying jig 7, or the workpiece 21 is lifted by the lower knockout pin 21 as shown in FIG. You may make it hold | grip with the conveyance jig 7. FIG.

(Embodiment 2)
With reference to FIG. 3, the forging apparatus 200 which is Embodiment 2 of this invention is demonstrated. 2A and 2B are diagrams illustrating a procedure of a wasteland forming process by the forging device 200, where FIG. 2A is a diagram illustrating a state of a molding top dead center, FIG. 2B is a diagram illustrating a state of a molding bottom dead center, and FIG. These are figures showing the state which conveys a workpiece | work to the following process. In addition, the same code | symbol is attached | subjected to the structure similar to Embodiment 1 mentioned above.

  The difference of the forging device 200 from the forging device 100 of the first embodiment is that the dimension in the depth direction of the engraving 2a of the upper mold 2 is smaller than the height of the workpiece 1 after the rough ground forming. That is, as shown in FIG. 3B, in the forging device 200, the surface 3 a facing the upper mold 2 in the lower mold 3 in the state of the molding bottom dead center does not fit within the mold carving 2 a of the upper mold 2. A clearance 31 exists between the opposing surfaces of the upper mold 2 and the lower mold 3.

  In the forging device 100 according to the first embodiment, the surface 3a of the lower mold 3 that faces the upper mold 2 in the state of molding bottom dead center is configured to be accommodated in the mold carving 2a of the upper mold 2. There is a possibility that a slight gap is generated between the inner wall surface 2b of the mold carving 2a and the side surface 3b of the lower mold 3 to cause vertical burrs on the work 1. However, according to the second embodiment, since the clearance 31 exists between the opposed surfaces of the upper mold 2 and the lower mold 3, no vertical burrs are generated in the work 1.

  Further, according to the second embodiment, as in the first embodiment, the lower mold 3 does not have a carving, and the surface 3a facing the upper mold 2 in the lower mold 3 is flat. Even when a scale accumulates in the lower mold 3, it can be easily removed, and the gripping surface 1 a can be gripped by the transport jig 7 while the workpiece 1 is placed on the lower mold 3.

(Embodiment 3)
With reference to FIG. 4, the forging apparatus 300 which is Embodiment 3 of this invention is demonstrated. 4A and 4B are diagrams illustrating a procedure of a wasteland forming process by the forging device 300, where FIG. 4A is a diagram illustrating a state of a molding top dead center, FIG. 4B is a diagram illustrating a state of a molding bottom dead center, and FIG. These are figures showing the state which conveys a workpiece | work to the following process. In addition, the same code | symbol is attached | subjected to the structure similar to Embodiment 1 mentioned above.

  The forging device 300 is different from the forging device 200 of the second embodiment in that a raised portion 3c is formed on the surface 3a of the lower die 3 that faces the upper die 2 in order to position the workpiece during rough ground forming in the horizontal direction. It is a point to be done.

  By providing the raised portion 3c on the surface 3a facing the upper die 2 in the lower die 3, the workpiece 1 on the lower die 3 can be easily positioned. Further, since the workpiece 1 is supported by the raised portion 3 c, the workpiece 1 is stably arranged on the lower mold 3. Therefore, since a stable load can be applied to the workpiece 1 in the waste land forming step, the load on the workpiece 1 can be reduced in the subsequent steps.

  By forming the raised portion 3c, a concave portion 41 is formed on the surface 3a of the lower die 3 facing the upper die 2. It is desirable that the depth of the recessed portion 41 is set to a size that allows the scale deposited on the surface 3a of the lower mold 3 to be easily discharged out of the mold and that the workpiece 1 can be stably placed on the lower mold 3. . Specifically, it is desirable to use a shallow engraved shape of 10 mm or less.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  The forging device of the present invention can be used in a forging device for manufacturing a hub used as an undercarriage part of an automobile.

It is a figure showing the procedure of the wasteland formation process by the forge apparatus 100 in Embodiment 1 of this invention. It is a figure showing the other aspect of the forging apparatus. It is a figure showing the procedure of the wasteland formation process by the forge apparatus 200 in Embodiment 2 of this invention. It is a figure showing the procedure of the wasteland formation process by the forge apparatus 300 in Embodiment 3 of this invention. It is a figure showing the forge process of a general hub. It is a figure showing the procedure of the conventional wasteland formation process. It is a figure showing the procedure of the conventional wasteland formation process.

Explanation of symbols

100, 200, 300 Forging device 1 Work 1a Grasping surface 2 Upper die 2a Mold engraving 2b Inner wall surface 3 Lower die 3a Face 3b opposite to upper die Side surface 3c Raised portion 4 Upper die knockout pin 6, 7 Conveying jig 21 Lower die Knockout pin 31 Clearance 41 Recess

Claims (5)

It is a forging device that performs a wasteland forming process that performs volume distribution of a workpiece among each forging process in a multistage forging method,
An upper die having a carved shape after the formation of the wasteland;
A forging device comprising a lower die having no mold carving.   The forging device according to claim 1, wherein a surface of the lower die that faces the upper die is a flat surface that fits within a die carving of the upper die at the time of molding bottom dead center. The depth direction dimension of the upper mold carving is smaller than the height of the workpiece after the rough ground molding,
The forging device according to claim 1, wherein a surface of the lower die facing the upper die is flat. The depth direction dimension of the upper mold carving is smaller than the height of the workpiece after the rough ground molding,
2. The forging device according to claim 1, wherein a raised portion that positions the workpiece in a horizontal direction is formed on a surface of the lower die that faces the upper die. It is a forging method in a wasteland forming process that performs volume distribution of a workpiece among each forging process in a multistage forging method,
A process of transporting the workpiece to the lower mold without mold carving,
A step of lowering the upper die having a shape carving of the shape after the wasteland molding to the bottom dead center of the molding, and molding the workpiece,
The step of raising the upper die from the bottom dead center of molding and releasing the workpiece from the upper die by the upper die knockout pin provided in the upper die,
A forging method comprising: holding a workpiece placed on the lower mold with a conveying jig and conveying the workpiece to the next process.

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