Die device for forging

Abstract

To provide a die device for forging that is capable of adequately forging a workpiece, even when the capability of a press machine required in forging is low.SOLUTION: A die device for forging comprises a guide post (5) having a piston (8) accommodated in an oil-pressure barrel section (6) fixed to a base (1) so as to be movable up and down, thereby allowing the guide post (5) to exhibit a tie-rod function.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a forging die device. [Background technology]

[0002] Conventionally, die devices used for forging bevel gears, CVJ inners, tripods, spiders, etc. have been configured and operated as follows. That is, a conventional method has been known in which an upper and lower mold are joined together to form a cavity, which is then closed so that it does not open during molding, and a punch is pressed into the mold (cavity) while maintaining this closed state to perform molding (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3466445 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional forging die devices require the application of a total load consisting of a load for closing the upper and lower dies and maintaining the closed state, and a load for pushing in the forming punch (die), which poses a problem in that the forming press requires a capacity greater than the sum of these two loads. In particular, in the automotive industry, with the recent shift to electric vehicles, molded products (parts) are becoming larger, and the increase in capital investment due to the upsizing (updating) of molding presses and other equipment is becoming a problem.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a forging die apparatus that can solve these problems, avoid the need for a large-sized forming press, and efficiently produce formed products. [Means for solving the problem]

[0006] The present invention provides a forging die apparatus in which a die set installed between a lower base and an upper press ram of a press machine includes a first die holder having an upper die, a second die holder having a lower die, and a guide post that guides the first die holder up and down while holding the first die holder and the second die holder so that they do not shift left and right or front and rear in a plan view; the guide post is connected to a piston that is housed in a hydraulic barrel fixed to the base and is capable of moving up and down; and the guide post is configured to function as a tie rod that brings the first die holder and the second die holder closer to each other.

[0007] Furthermore, the present invention is configured such that the guide post performs the tie rod function, causing the first die holder and the second die holder to approach each other, maintaining the upper die and the lower die in a closed state, and with the workpiece to be forged held by the lower die, the upper end of the forming pin maintains a state in which it protrudes from the upper surface of the first die holder; and the pressing force of the press ram pushes the upper end of the forming pin in the protruding state downward, completing the forging of the workpiece. [Effects of the Invention]

[0008] In the forging die device according to the present invention, the guide post functions as a tie rod using the piston in the hydraulic barrel. This tie rod function allows the upper and lower dies to be closed in a vertically pressed-contact state while maintaining the first and second die holders in a state close to each other. Therefore, the load required for closing the upper and lower dies in a pressed-contact state by the press (press ram) can be significantly reduced. In this way, the (required) capacity of the press machine is limited to the load required to push the forming pins into the cavity, which is necessary for forming the workpiece. This prevents the press machine from becoming larger (higher load), and avoids higher costs. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a main part in an open state, showing one embodiment of the present invention; [Figure 2]FIG. 10 is a cross-sectional view of a main part showing a state during work formation. [Figure 3] FIG. 10 is a cross-sectional view of the main part showing the completion of workpiece forming. [Figure 4] FIG. 2 is a hydraulic circuit diagram corresponding to the state of FIG. 1. [Figure 5] FIG. 3 is a hydraulic circuit diagram corresponding to the state of FIG. 2. [Figure 6] FIG. 4 is a hydraulic circuit diagram corresponding to the state of FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below based on the illustrated embodiments. 1 to 3, P denotes a press machine, which is equipped with a lower base 1 and an upper press ram 2. A die set Ds (which is replaceable) is installed in the space between the base 1 and the press ram 2 of this press machine P.

[0011] The die set Ds includes a (upper) first die holder 3 having an upper die 11, a (lower) second die holder 4 having a lower die 12, and a guide post 5. The guide post 5 guides the first die holder 3 up and down while holding the first die holder 3 and the second die holder 4 so that they do not shift positionally left and right or front and rear in a plan view.

[0012] Moreover, this guide post 5 is connected to a piston 8 housed in a hydraulic barrel portion 6 fixed to the base 1 so as to be movable up and down. Therefore, the guide post 5 functions as a tie rod that brings the first die holder 3 and the second die holder 4 closer to each other. This tie rod function applies a pressing force to the upper die 11 of the first die holder 3 against the lower die 12 of the second die holder 4, closing the upper die 11 and the lower die 12 and maintaining the closed state so that they do not open during subsequent molding.

[0013] It can be said that the hydraulic cylinder is made up of the hydraulic barrel 6, piston 8, and guide post 5 (as a piston rod). Usually, four guide posts 5 are provided, but it is preferable that all guide posts 5 have a piston 8 and a hydraulic barrel 6.

[0014] Due to the tie rod function of the guide post 5, the first die holder 3 and the second die holder 4 are close to each other (as shown in Figures 1 and 2), the upper die 11 and the lower die 12 are kept closed, and the workpiece W to be forged is held by the lower die 12, and the upper end 10A of the forming pin 10 is kept protruding by a predetermined dimension ΔH from the upper surface 3A of the first die holder 3 (see Figure 2).

[0015] Thereafter, as shown in Figures 2 and 3, the upper end 10A of the forming pin 10, which was in an upwardly protruding state, is pressed downward by the downward pressing force F2 applied by the press ram 2, thereby completing the forging of the workpiece W (see Figure 3). In Figures 1 to 3, a small-diameter punch pin 13 is provided at the lower end of the forming pin 10 in a protruding shape, which works together with the lower die pin 14 to directly forge the workpiece W and plastically deform it into a predetermined shape.

[0016] A piston 17 is housed in the hydraulic chamber 16 at the lower position, allowing it to move up and down in short strokes. As shown in Figures 2 and 3, this piston 17 causes the upper die 11, lower die 12, etc. to move down a small distance during forging, thereby ensuring reliable and highly accurate forming of the workpiece W. The upper end of a piston 19 is housed in the upper hydraulic chamber 18 so that it can move up and down in short strokes. When the piston 19 descends, the upper die 11 and the lower die 12 (corresponding to the descent of the forming pins 10 and punch pins 13) are lowered as shown in Figures 2 and 3.

[0017] Next, Figures 4, 5 and 6 are diagrams corresponding to the above-mentioned Figures 1, 2 and 3, respectively, to which a hydraulic circuit, hydraulic pumps 21, 21 and valves have been added. 4 to 6, two sets of hydraulic pump 21 and drive motor M are installed. By providing two sets, the forging speed and the like can be selected according to the type, shape, size, etc. of the workpiece.

[0018] Furthermore, a high-pressure oil supply / low-pressure oil discharge switching circuit L1 having an electromagnetic switching valve 22, a relief valve 23, etc. is provided to raise and lower the piston 8 inside the hydraulic barrel portion 6 and move the guide post 5 up and down. The relief valve 23 is added to this circuit L1. Furthermore, a high-pressure oil supply circuit L2 is provided that branches off from the discharge pipes 24, 24 of the hydraulic pumps 21, 21 (at branch points 25, 25) and sends high-pressure oil to the hydraulic chambers 16, 18 that house the pistons 17, 19.

[0019] This high-pressure oil supply circuit L2 branches at a branch point 28, one of which is connected to the hydraulic chamber 16 of the piston 17 via a branch pipe 29, and the other of which is connected to the hydraulic chamber 18 of the piston 19 via a branch pipe 30. Moreover, a check valve 31 and an electromagnetic ON-OFF switching valve 32 are interposed midway in the branch pipe 30. Furthermore, a return pipe 34 is disposed midway in the branch pipe 30, branching off to return the water to the tank 33. Moreover, an electromagnetic ON-OFF switching valve 35, which is normally in the OFF state, is interposed in this return pipe 34.

[0020] In the state shown in Figures 4 and 1, high-pressure oil discharged from the hydraulic pumps 21, 21 is sent via the switching valve 22 to the space below the piston 8 connected to the lower side of the guide post 5, pushing up the first die holder 3 and opening the upper die 11 and the lower die 12.

[0021] 5 and 2, the switching valve 22 is switched so that the high-pressure oil discharged from the hydraulic pumps 21, 21 is sent to the space above the piston 8 in the hydraulic barrel portion 6, moving the piston 8 and the guide post 5 downward, and lowering the first die holder 3 to close the upper die 11 and the lower die 12. At this time, the upper end portion 10A of the forming pin 10 protrudes from the upper surface 3A of the first die holder 3.

[0022] Thereafter, the state shown in FIG. 6 and FIG. 3 is reached, and the press ram 2 of the press machine P moves downward to press down the upper end 10A of the forming pin 10, thereby enabling the workpiece W to be forged.

[0023] As described above in detail, the present invention relates to a forging die apparatus in which a die set Ds installed between the lower base 1 and the upper press ram 2 of a press P includes a first die holder 3 having an upper die 11, a second die holder 4 having a lower die 12, and a guide post 5 that guides the first die holder 3 up and down while holding the first die holder 3 and the second die holder 4 so that they do not shift left and right, front and rear in a plan view; the guide post 5 is connected to a piston 8 that is housed in a hydraulic barrel 6 fixed to the base 1 and is capable of moving up and down; and the guide post 5 is configured to function as a tie rod that brings the first die holder 3 and the second die holder 4 closer to each other. Therefore, it is sufficient for the press P to generate a pressing force sufficient to press the forming pins 10 against the workpiece W (a pressing force significantly smaller than conventional press forces is sufficient), thereby significantly reducing the capital investment costs for the press P.

[0024] Furthermore, the tie rod function of the guide post 5 allows the first die holder 3 and the second die holder 4 to approach each other, maintaining the upper die 11 and the lower die 12 in a closed state, and with the workpiece W to be forged held by the lower die 12, the upper end 10A of the forming pin 10 is kept protruding from the upper surface 3A of the first die holder 3; and the pressing force F2 of the press ram 2 pushes the protruding upper end 10A of the forming pin 10 downward, completing the forging of the workpiece W. This configuration requires only minor modifications to the guide post 5, thereby reducing capital investment costs for increasing the capacity of the press machine P. Another advantage is that noise generated during the forging process can be reduced. [Explanation of symbols]

[0025] 1. Foundation 2 Press Ram 3 First die holder 3A Top 4 Second die holder 5 Guidepost 6 Hydraulic barrel section 8 pistons 10 Molded Pins 10A upper end 11 Upper die 12 Lower die Ds die set F2 pressing force P press machine W Forged workpiece

Claims

1. A forging die device in which a die set (Ds) installed between a lower base (1) and an upper press ram (2) of a press machine (P) includes a first die holder (3) having an upper die (11), a second die holder (4) having a lower die (12), and a guide post (5) that guides the first die holder (3) up and down while holding the first die holder (3) and the second die holder (4) so ​​that they do not shift left and right, or front and rear in a plan view. The guide post (5) is connected to a piston (8) housed in a hydraulic barrel (6) fixed to the base (1) so as to be movable up and down; The guide post (5) is configured to function as a tie rod that brings the first die holder (3) and the second die holder (4) closer to each other. A forging die device characterized by:

2. The tie rod function of the guide post (5) causes the first die holder (3) and the second die holder (4) to approach each other, maintaining the upper die (11) and the lower die (12) in a closed state, and with the workpiece (W) held by the lower die (12), the forming pin (10) maintains its upper end (10A) protruding from the upper surface (3A) of the first die holder (3). The pressing force (F 2 2. The forging die device according to claim 1, wherein the upper end (10A) of the forming pin (10) in the protruding state is pushed downward by a force of the forging die.

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