JP3455461B2 - Closed forging device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a closed forging device. More specifically, it relates to a closed forging device for punching a through hole in a material.

[0002]

2. Description of the Related Art As a conventional example of a closed forging device, Japanese Patent Publication No.
There is one described in Japanese Patent No. 37806. In this conventional example, an upper cylinder is formed in an upper die holder main body attached to a slide, and the upper die is vertically movably supported by the upper cylinder, and an upper punch that can be fitted into the upper die is provided in the upper die holder. It is provided so as to be integrated with the main body,
A lower cylinder having the same pressure receiving area as that of the upper cylinder is formed on the lower die holder body mounted on the bed, and the lower cylinder supports the lower mold so that it can move up and down, and the lower mold can be fitted into the lower mold. A punch is provided integrally with the lower die holder main body, and the upper and lower cylinders are connected to oil chambers in which pistons are connected by connecting rods and which have the same pressure receiving surface.

[0003]

In the above-mentioned conventional example, as shown in FIG.
When the upper and lower punches are thrust into the material W as shown in, after the mold is clamped by the upper and lower molds, holes in the material W are formed from above and holes in the material W are formed from below to form a substantially H shape. An intermediate material Wa having a hole is formed (see). However, the work of the closed forging device is up to this point, and the medium burr b remains on the material. The middle burr b must be burred by another device as shown in the figure, or must be cut and removed by a drill or the like.

Therefore, in the above-mentioned conventional example, the work efficiency is poor and the productivity is low because the middle deburring is a separate step. In view of such circumstances, the present invention enables medium deburring to be performed in one operation subsequent to punch hole forming,
An object is to provide a closed forging device with improved productivity.

[0005]

A closed forging device according to claim 1, wherein an upper die attached to an upper die holder via an upper die plate and a lower die attached to a lower die holder via a lower die plate. A closed forging device including a die clamping cylinder attached between the upper die holder and the lower die holder, wherein an upper punch provided through the upper die plate and the upper die, Formed on the lower die holder, an upper piston that is attached to the upper die holder so as to be able to move up and down, and that lowers the upper punch by receiving a pressing force of a slide, a lower punch that is provided through the lower die plate and the lower die, and a lower die holder. In the supporting cylinder chamber, which moves up and down the lower punch, and the upper and lower dips at a speed that is half the lowering speed of the upper piston lowered by the slide. A drop means for lowering over bets, characterized in that comprising a discharge means for the blocking allows the discharge of the pressurized oil of the support cylinder chamber or for supporting the lower piston. According to a second aspect of the present invention, in the closed forging apparatus according to the first aspect of the invention, the lowering means is formed in the upper die holder, and the upper die plate is inserted in a liquid-tight and vertically movable manner; A lower cylinder chamber formed in a die holder, in which the lower die plate is inserted in a liquid-tight manner and capable of moving up and down, a communication circuit for communicating the upper cylinder chamber and the lower cylinder chamber, and the lower cylinder chamber to the upper cylinder chamber. The opening / closing means for allowing or blocking the inflow of pressure oil, the pressure receiving area of the upper die plate in the upper cylinder chamber is larger than the pressure receiving area of the lower die plate in the lower cylinder chamber. To do. According to a third aspect of the present invention, in the closed forging device according to the second aspect, the lowering means adjusts an inflow amount of the pressure oil flowing into the communication circuit from the lower cylinder chamber to the upper cylinder chamber. Is provided. According to a fourth aspect of the present invention, in the closed forging device according to the second aspect, the opening / closing means includes a first pilot check valve and a second pilot check valve which are provided in the communication circuit, and the first pilot check valve. A stop valve and a pilot control valve that controls the pilot pressure of the second pilot check valve. The first pilot check valve prevents pressure oil from flowing into the upper cylinder in a state where no pilot pressure is applied. The second pilot check valve is interposed in a direction that prevents discharge of pressure oil from the lower cylinder in a state where no pilot pressure is applied. According to a fifth aspect of the present invention, in the closed forging device according to the first aspect of the invention, the discharge means allows the discharge circuit connected to the support cylinder chamber to communicate with the relief valve and the tank when pilot pressure acts on the pilot circuit. It is characterized by being equipped with a check valve.

According to the first aspect of the invention, the upper punch is slid down while the material is clamped by the upper and lower dies,
By lowering the upper and lower die plates at a speed half that of the upper punch by the lowering means and stopping the lower punch, holes are formed in the upper and lower portions of the material and the filling of the meat is improved. Then, lowering the lower piston lowers the upper and lower punches as the slide lowers, so the middle burr can be removed in one motion. According to the second aspect of the invention, since the pressure oil flows from the lower cylinder chamber to the upper cylinder chamber by the opening / closing means in the communication circuit, the lower die plate can be lowered separately from the upper punch. Become smooth. According to the invention of claim 3, the flow rate adjusting means can adjust the inflow amount of the pressure oil from the lower cylinder chamber to the upper cylinder chamber, so that the lowering speed of the upper and lower die plates can be adjusted to half the lowering speed of the upper punch. According to the invention of claim 4,
Although the inflow of pressure oil from the lower cylinder chamber to the upper cylinder chamber is normally blocked by the first and second pilot check valves, the inflow is allowed when the pilot pressure is applied by operating the pilot control valve. In this way, the lowering of the upper and lower die plates can be controlled only by operating the pilot control valve, which facilitates the operation. According to the invention of claim 5, the lower piston can be started to descend only by opening and closing the pilot check valve in the discharge circuit, so that the middle deburring process can be smoothly performed in one motion.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a configuration explanatory view of a closed forging device according to an embodiment of the present invention, FIG. 2 is an enlarged view of a main part in a state where the upper piston 13 and the upper punch 11 are in contact with each other in the closed forging device, and FIG. 3 is a pilot control valve. Is an explanatory view showing another example, FIG. 4 is an explanatory view of a forging process in the closed forging device of the present invention, and FIG. 5 is a time chart of the forging process.

In FIG. 1, 1 is an upper die holder, 2 is a lower die holder, 3 is an upper die plate, and 4 is a lower die plate. The upper die plate 3 is inserted in an upper cylinder chamber 5 formed in the upper die holder 1 so as to be liquid-tight and movable up and down. The lower die plate 4 is inserted in a lower cylinder chamber 6 formed in the lower die holder 2 so as to be liquid-tight and movable up and down. An upper die 7 is attached to the lower surface of the upper die plate 3,
A lower die 8 is attached to the upper surface of the lower die plate 4. A material W is placed between the upper mold 7 and the lower mold 8.

The upper punch 11 is inserted vertically through the upper die plate 3 and the upper die 7, and the lower punch 12 is vertically inserted through the lower die plate 4 and the lower die 8. There is. A cylindrical recess 15 is formed in the upper die holder 1 from its upper surface to the upper cylinder chamber 5, and an upper piston 13 is vertically inserted therein. The lower surface of the upper piston 13 hits the upper punch 11, and the upper punch 11 can be pushed down. A support cylinder chamber 16 is formed in the lower die holder 2, and a lower piston 14 is vertically movable therein. The upper surface of the lower piston 14 hits the lower punch 12, and the lower punch 12
Can be raised and lowered. A slide 10 applies downward pressure to the upper piston 13.

Details of the above structure will be described with reference to FIG. A is a pressure receiving area where the upper piston 13 receives hydraulic pressure in the upper cylinder chamber 5, A3 is a pressure receiving area where the upper die plate 3 receives hydraulic pressure in the upper cylinder chamber 5, and A4 is a lower cylinder chamber 6 and the lower die plate 4 Is the pressure receiving area that receives oil pressure. In the later-described punch forming process, the upper and lower molds 7 and 8 are pressed downward while being clamped to each other. Therefore, the pressing force of the upper die plate 3 must be larger than the pressing force of the lower die plate 4. I have to. Therefore, the pressure receiving area A3 of the upper die plate 3 is slightly larger than the pressure receiving area A4 of the lower die plate 4.

Referring again to FIG. 1, a mold clamping cylinder 18 is attached between the upper die holder 1 and the lower die holder 2. The piston of this mold clamping cylinder 18
18 a is put in a cylinder chamber 18 b formed in the upper die holder 1, and the piston rod 18 c is connected to the lower die holder 2. In addition, this mold clamping cylinder 18 is shown in FIG.
Although only a book is shown, in order to perform the mold clamping between the upper and lower molds 7 and 8 in a well-balanced manner,
Alternatively, they are provided on the left and right sides.

Next, the descending means will be described. A communication circuit 20 is connected between the upper cylinder chamber 5 in the upper die holder 1 and the lower cylinder chamber 6 in the lower die holder 2 so that they communicate with each other. An accumulator 30 and a pressure release valve 31 are provided in the middle of the communication circuit 20. The pressure relief valve 31 is for releasing the amount of oil once absorbed by the accumulator 30 in a later step.
In the communication circuit 20 between the accumulator 30 and the upper cylinder chamber 5, a relief valve 32 and a check valve 33 that blocks the outflow from the upper cylinder chamber 6 are interposed. The relief valve 32 and the check valve 33 constitute a holding means that regulates the pressure in the upper cylinder chamber 5 during mold clamping.

The check valve 33 and the accumulator 30
A first pilot check valve 34, which blocks the inflow to the upper cylinder chamber 5, is interposed therebetween. The first pilot check valve 34 opens when a pilot pressure is applied to allow the pressure oil to flow into the upper cylinder chamber 5. The lower cylinder chamber 6
A second pilot check valve 35 for preventing pressure oil from being discharged from the cylinder chamber 6 is interposed between the cylinder accumulator 30 and the accumulator 30. When pilot pressure is applied to the second pilot check valve 35, the valve is opened to allow the pressure oil to flow from the lower cylinder chamber 6 to the upper cylinder chamber 5. A pilot circuit 21 is connected to the first pilot check valve 34 and the second pilot check valve 35, and the pilot control valve 2
2, the pilot pressure can be applied. The first and second pilot check valves 34 and 35 and the pilot control valve 22 constitute an opening / closing means.

A flow throttle valve 36 with a check valve is interposed between the second pilot check valve 35 and the accumulator 30. The throttle amount of the flow rate throttle valve 36 is variable, and the inflow amount of the pressure oil from the lower cylinder chamber 6 to the upper cylinder chamber 5 can be variably adjusted. This flow restrictor 36
The flow rate adjusting means in the claims is constituted by the above. The oil passage 23, the opening / closing valve 24 and the pilot check valve 38 connected to the communication circuit 20 on the lower cylinder chamber 6 side of the throttle valve 36 are for preload, and the opening / closing valve 24 is switched to connect the oil passage 20 and the pump. When connected, the lower die plate 4 can be held at the upper limit position.

The support cylinder chamber 16 has a discharge circuit 2
5 is connected, and a relief valve 37 and a check valve 39 with a pilot are interposed in the discharge circuit 25. The pilot of the check valve 39 with pilot is the pilot control valve 26.
The check valve 39 opens when the pilot pressure is supplied by the valve.

The pilot control valve 22 shown in FIG. 1 is of a solenoid type and is excited by the output of a signal in accordance with the slide descending timing. Since the pilot control valve 22 may be opened / closed at the same timing as the slide 10, the pilot control valve 22 is not limited to the solenoid type and may be opened / closed by a cam 27 that moves up and down in conjunction with slide as shown in FIG. .

The communication circuit 20 allows pressure oil in the lower cylinder chamber 6 to flow into the upper cylinder chamber 5 in order to lower the upper and lower die plates 3 and 4 in a clamped state during punch forming. The amount V of replenishment oil required to be replenished to the upper cylinder chamber 5 is obtained by the following formula. V = A3 × {S4− (A / A3 × S)} where A: pressure receiving area of the upper piston 13 A3: pressure receiving area of the upper die plate S4: lowering stroke S of the lower die plate 4 S: lowering of the upper piston 13 Stroke This supply amount V of oil is covered by a part of the amount of oil discharged from the lower cylinder chamber 6, and the surplus pressure oil is stored in the accumulator 30.
Is absorbed by.

Next, the forging work by the closed forging device will be described with reference to FIGS. I Standby position In the state shown in I of FIG. 4, the upper and lower molds 7 and 8 and the upper and lower punches 11 and 12 are separated from each other. The material W is placed on the lower die 8.

II Preform Molding and Mold Clamping Step The slide is lowered from the state of the above I, and the upper piston 1
Drop 3 The operation of the entire apparatus is as shown in FIG. 1, and the mold part is as shown by II in FIG. As shown in FIG. 5, the slide descends in the area II near the bottom dead center. At this time, the upper cylinder chamber 5 is closed by the relief valve 32 and the check valve 33. When the upper piston 13 descends, the pressure in the upper cylinder chamber 5 is reduced to the relief valve 32.
Up to the set pressure, and the upper die plate 3 is pushed down via this high pressure oil. On the other hand, since the lower die plate 4 is supported by the hydraulic pressure in the lower cylinder chamber 6 and the lower mold 8 does not descend, the upper mold 7 is pressed against the lower mold 8 to preform the material W and clamp the mold. . In this state, the upper punch 11
Further, the pressing force of the upper piston 13 is not directly applied. During this process, the force applied to the upper punch 11 is such that the collar portion 11a of the upper punch 11 receives the seat 3 of the upper die plate 3 as shown in FIG.
By hitting a, the upper die plate 3 takes charge,
The upward force in the upper cylinder chamber 5 is taken up by the hydraulic pressure in the cylinder chamber 18b of the mold clamping cylinder 18.

III Punch Forming Step When the die clamping step of the above II is completed and the slide is further lowered to enter the punch forming step III as shown in FIG.
As shown in, the upper piston 13 comes into contact with the upper punch 11 to start punch forming. At the same time, the pilot control valve 22 that has detected the slide position operates to open the pilot check valves 34 and 35. As a result, the lower cylinder chamber 6 communicates with the upper cylinder chamber 5 via the communication circuit 20, and the pressure oil in the lower cylinder chamber 6 is supplied to the upper cylinder chamber 5. In this case, the flow rate of the hydraulic oil from the lower cylinder chamber 6 to the upper cylinder chamber 5 is throttled by the flow throttle valve 36, and the lowering speed of the lower die plate 4 is adjusted to be 1/2 that of the upper piston 13. That is, with respect to the stroke amount S of the upper punch 13,
The lowering stroke S4 of the lower die plate 4 is 1 / 2.S.

As described above, the pressure receiving area A4 of the lower die plate 4 is larger than the pressure receiving area A3 of the upper die plate 3, and the upper cylinder chamber 5 has an oil amount V enough to clamp the upper and lower die plates 3 and 4. Since it is replenished, the upper and lower die plates 3 and 4 are not separated from each other. Since the support cylinder chamber 16 is closed by the relief valve 37 and the pilot check valve 39, the lower piston 14 does not lower. In this state, the upper piston 1
3 descends, and when the upper and lower die plates 3 and 4 descend at half the descending speed, the upper punch 11 and the lower punch 12 are pushed in from above and below the material W, as shown in III of FIG. The upper and lower punched holes are formed in. At this time, since the pushing amounts of the upper and lower punches 11 and 12 are the same, the filling of the meat is also improved.

IV Medium Deburring Step After the punch forming step of the above-mentioned III is finished, the medium deburring step IV follows. As shown in FIG. 5, this step is performed by slide-down from the punch forming completion time to the device bottom dead center D. That is, the pilot control valve 22 is switched to the position simultaneously with the completion of the punch forming step III, the first and second pilot check valves 34 and 35 are returned to the closed state, and at the same time, the pilot control valve 26 is switched to the position and the check valve 39.
Open up. As a result, the lower piston 14 can be lowered, so that the upper punch 1
1 descends, and lower punch 12 descends. By the descending stroke T of the upper punch 11 at this time, the center burr b is punched out downward as shown by IV in FIG.

[0023]

According to the first aspect of the present invention, when the upper punch is slid down, the upper and lower die plates are lowered at half the speed of the upper punch, and the lower punch is stopped, holes are punched above and below the material. Is formed, and when the lower piston is subsequently lowered, the upper and lower punches are also lowered due to the slide lowering, so middle burr removal can be done in one motion. Claim 2
According to the invention, since the pressure oil flows into the upper cylinder chamber from the lower cylinder chamber by the opening / closing means in the communication circuit, the lowering of the upper and lower die holders can be performed separately from the lowering of the upper punch, so that the one-motion operation becomes smooth. According to the invention of claim 3, the flow rate adjusting means can adjust the inflow amount of the pressure oil from the lower cylinder chamber to the upper cylinder chamber, so that the lowering speed of the upper and lower die holders can be adjusted to half the lowering speed of the upper punch.
According to the invention of claim 4, the flow of the pressure oil from the lower cylinder chamber to the upper cylinder chamber is controlled only by operating the pilot control valve for opening the first and second pilot check valves. As the descent can be controlled, it is easy to operate. According to the invention of claim 5, the lower piston can be started to descend only by opening and closing the pilot check valve in the discharge circuit.
Smooth deburring process with one motion.

[Brief description of drawings]

FIG. 1 is a configuration explanatory view of a closed forging device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of an essential part of a state in which the upper piston 13 and the upper punch 11 are in contact with each other in the closed forging device.

FIG. 3 is an explanatory diagram showing another example of a pilot control valve.

FIG. 4 is an explanatory view of a forging process in the closed forging device of the present invention.

FIG. 5 is a time chart of the forging process.

FIG. 6 is a process drawing of a conventional closed forging device.

[Explanation of symbols]

1 Upper die holder 2 Lower die holder 3 Upper die plate 4 Lower die plate 5 Upper cylinder chamber 6 Lower cylinder chamber 7 Upper mold 8 Lower mold 10 slides 11 Upper punch 12 Lower punch 13 Upper piston 14 Lower piston 20 communication circuits 22 Pilot control valve 30 accumulator 34 Check valve with pilot 35 Check valve with pilot 36 Flow restrictor

Continuation of the front page (56) Reference JP 2000-42674 (JP, A) JP 4-288997 (JP, A) JP 55-88945 (JP, A) JP 11-197779 (JP, A) Japanese Patent Laid-Open No. 10-85890 (JP, A) Japanese Patent Laid-Open No. 8-300093 (JP, A) Japanese Patent Publication No. 3-37806 (JP, B2) Japanese Patent Publication No. 60-5382 (JP, B2) (58) Survey Fields (Int.Cl. ⁷ , DB name) B21J 1/00-13/14 B21J 17/00-19/04 B21K 1/00-31/00

Claims (5)

(57) [Claims] 1. An upper die attached to an upper die holder via an upper die plate, a lower die attached to a lower die holder via a lower die plate, and between the upper die holder and the lower die holder. A closed forging device equipped with an attached die clamping cylinder, comprising: an upper punch provided through the upper die plate and the upper die; and a slide pressing force attached to the upper die holder so as to be movable up and down. An upper piston that receives the lower punch and lowers the upper punch, and a lower punch provided through the lower die plate and the lower die,
A lower piston that is inserted into a support cylinder chamber formed in the lower die holder and that lowers and lowers the lower punch, and lowers and lowers the upper and lower die plates at a speed that is half the lowering speed of the upper piston that is lowered by the slide. A closed forging device comprising: a means and a discharge means that allows or blocks discharge of pressure oil in the support cylinder chamber that supports the lower piston. 2. The lowering means is formed in the upper die holder, the upper die chamber is formed in the upper cylinder chamber into which the upper die plate is liquid-tightly and vertically movable, and the lower die holder is formed in a liquid-tight manner. And a lower cylinder chamber that is vertically inserted, a communication circuit that connects the upper cylinder chamber and the lower cylinder chamber, and opening / closing means that allows or blocks the flow of pressure oil from the lower cylinder chamber to the upper cylinder chamber. The closed forging device according to claim 1, wherein the pressure receiving area of the upper die plate in the upper cylinder chamber is larger than the pressure receiving area of the lower die plate in the lower cylinder chamber. 3. The lowering means is characterized in that the communication circuit is provided with a flow rate adjusting means for adjusting an inflow amount of pressure oil flowing from the lower cylinder chamber to the upper cylinder chamber. Item 2. The closed forging device according to item 2. 4. The opening / closing means includes a first pilot check valve and a second pilot check valve interposed in the communication circuit, and pilot pressures of the first pilot check valve and the second pilot check valve. The first pilot check valve is interposed in a direction for preventing pressure oil from flowing into the upper cylinder in a state where no pilot pressure is applied, and the first pilot check valve is provided. The closed forging device according to claim 2, wherein the stop valve is interposed in a direction in which pressure oil discharge from the lower cylinder is blocked in a state where no pilot pressure is applied. 5. The discharge means has a discharge valve connected to the support cylinder chamber and a relief valve and a pilot check valve for permitting communication with the tank when a pilot pressure acts. The closed forging device according to claim 1, wherein: