Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
  • B21J9/00—Forging presses
  • B21J9/10—Drives for forging presses
  • B21J9/12—Drives for forging presses operated by hydraulic or liquid pressure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
  • B21J9/00—Forging presses
  • B21J9/10—Drives for forging presses
  • B21J9/20—Control devices specially adapted to forging presses not restricted to one of the preceding subgroups
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B30—PRESSES
  • B30B—PRESSES IN GENERAL
  • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
  • B30B15/16—Control arrangements for fluid-driven presses
  • B30B15/18—Control arrangements for fluid-driven presses controlling the reciprocating motion of the ram
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B30—PRESSES
  • B30B—PRESSES IN GENERAL
  • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
  • B30B15/16—Control arrangements for fluid-driven presses
  • B30B15/18—Control arrangements for fluid-driven presses controlling the reciprocating motion of the ram
  • B30B15/20—Control arrangements for fluid-driven presses controlling the reciprocating motion of the ram controlling the speed of the ram, e.g. the speed of the approach, pressing or return strokes

Definitions

• the present invention relates to a plastic working method using a press device, and more particularly to a plastic working method for preventing deterioration of product accuracy due to deformation of a die during plastic working.
• the force applied from the nonch to the blank is also transmitted to the die as stress. So the die is absolutely Since the die cannot have such rigidity, it is inevitable that the die deforms during plastic working. In particular, in the case of a device that applies strong pressure, such as a cold forging press device, the die deformation is large.
• the present invention has been made in view of such problems, and has as its object to provide a plastic working method with improved working accuracy so that sufficient product accuracy can be obtained without post-processing. I do.
• the plastic working method of the present invention includes a punch whose moving speed can be controlled by fluid pressure, a die on which a blank is mounted, a support means for preventing the punch from moving forward by fluid pressure, and a formed blank.
• a plastic working apparatus having an ejecting means for ejecting the workpiece by fluid pressure
• a plastic working method of plastically deforming the blank by applying a pressure that causes plastic deformation to the blank mounted on the blank through the punch, wherein the punch is pressed until the tip of the punch contacts the blank.
• Step 3 and the strain rate generated in the blank due to the molding pressure applied through the punch is substantially the same as during the plastic working.
• the effect of the impact of a punch hitting the blank can be reduced by slowly moving the punch forward until the tip of the punch contacts the blank.
• m is the strain rate response index
• the blank when the punch and the blank are in contact with each other, the blank is plastically deformed by the fluid pressure for advancing the punch while supporting the force of the punch to advance by the backup cylinder acting as a support means.
• the pressure supported by the backup cylinder is applied to the blank to increase the punch advance speed more quickly to the ideal speed. I have.
• the fluid pressure for advancing the counter punch is changed to the fluid pressure for advancing the punch in a state where fluid pressure is applied to both the punch and the punch acting as an ejecting means.
• the blank is ejected from the die by advancing the counterpunch while applying pressure to the blank by raising it relatively. You. Therefore, die springback does not occur until the molded product escapes from the die, so that damage to the molded product due to the springback can be avoided.
• FIG. 1 is a block diagram of a cold forging press device and a control system thereof according to an embodiment of the present invention.
• Figure 2 is an enlarged view around the die.
• Fig. 3 is a flowchart of the control operation.
• FIG. 1 is a block diagram of a cold forging press 1 and a control system thereof according to one embodiment of the present invention.
• a bet 3 and a cylinder fixing plate 4 are fixed to a frame 2 of a cold forging press 1 in parallel.
• the main cylinder 5 is fixed to the cylinder fixing plate 4.
• a slide 7 is fixed to the lower end face of the piston 6 of the main cylinder 5.
• the slide 7 is raised and lowered by the piston 6.
• a punch 9 is attached to a lower end surface of the slide 7 via a fixing member 8.
• a die 11 is attached to the upper end surface of the bed 3 directly below the punch 9 via a fixing member 10.
• a blank 12 to be processed is mounted on the die 11.
• a backup series supporting slide 7 from below is provided on the upper end surface of bed 3. 1 and 3 are fixed.
• the piston 14 of the cup cylinder 13 has a stroke that can reach the lower end surface of the slide 7.
• Knockout cylinder 15 is fixed to the lower end surface of bed 3.
• the piston in the knockout cylinder 15 acts as a counter punch 16 for knocking out the plastically worked blank 12.
• the control unit 20 is a control device.
• the control unit 20 is a main CPU 21 that controls the entire system, a sub CPU 22 that controls each control target, and a data CPU 25 that controls the input and output of memory data. It has an external output device 26 such as a CRT, an external output device such as a keyboard and an external memory. '
• the main cylinder 5 has a flow control valve 31 for controlling the amount of oil flowing into the main cylinder 5, a pressure control valve 32 for controlling the pressure in the main cylinder 5, and a pressure for detecting the pressure in the main cylinder 5.
• Sensor 33 is provided.
• the flow control valve 31 and the pressure control valve 32 are controlled by the controller 20 via drivers 34 and 35, respectively. Further, the detection output of the pressure sensor 33 is input to the control device 20 via the amplifier 36.
• the backup cylinder 13 is provided with a high-speed responsive three-way (forward, backward, and hold) directional control valve 37 that switches the direction of oil flow.
• the direction switching valve 37 is controlled by the control device 20 via the driver 38.
• Reference numeral 39 denotes a photoelectric conversion type position sensor that detects the position of the slide 7.
• Reference numeral 40 denotes a speed converter for differentiating the output of the position sensor 39 and converting it into the operating speed of the slide 7. Outputs of the position sensor 39 and the speed converter 40 are input to the control device 20 via the counter 41.
• the knockout cylinder 15 has a pressure inside the knockout cylinder 15.
• a pressure control valve 42 for controlling the pressure and a pressure sensor 43 for detecting the pressure in the knockout cylinder 15 are provided.
• the pressure control valve 42 is controlled by the controller 20 via the driver 44.
• the detection output of the pressure sensor 43 is input to the control device 20 via the amplifier 45.
• Reference numeral 46 denotes a photoelectric conversion type position sensor that detects the position of the counter punch 16.
• Reference numeral 47 denotes a speed converter for differentiating the output of the position sensor 46 and converting it into the operation speed of the counter punch 16. Outputs of the position sensor 46 and the speed converter 47 are input to the control device 20 via the counter 48.
• various data for example, the position of the slide 7 when the lower end surface of the punch 9 contacts the blank 12, the pressure at the discharge point of the blank 12, The pressurizing speed corresponding to the position of slide 7) is input from the external input device 29 and set in the data CPU 25.
• control device 20 controls the flow control valve 31 via the driver 3.
• control device 20 inputs the output of the position sensor 39 via the counter 41 and monitors the position of the slide 7.
• the controller 20 controls the directional control valve 37 via the driver 38 to control the backup serial. Oil is supplied to the cylinder 13 to raise the piston 14, and the slide 7 is supported by the backup cylinder 13.
• the controller 20 confirms that the position of the slide 7 does not fluctuate due to the output of the position sensor 39, and checks the flow control valve 31 and the pressure control valve. 3 2 and the directional control valve 37 are controlled to increase the pressure of the main cylinder 5 and the backup cylinder 13.
• the controller 20 controls the directional control valve 37 to perform the backup series. Opener 13 and control flow control valve 31 to lower slide 7. No., the pressure generated by the main cylinder 5 due to the release of the pickup cylinder 13 is applied to the blank 12, and the blank 9 is plastically deformed by the punch 9.
• the control device 20 determines the slide position, which is the output of the position sensor 39, and the pressurizing speed, which is the output of the speed converter 40. By controlling the flow control valve 31 while monitoring, the pressurization speed is controlled so that the slide 7 descends at a constant speed.
• the slide 7 is naturally lowered by this pressurizing operation.
• control device 20 controls the directional control valve 37 to operate the knock-up cylinder 13 Braking is applied to the descent of slide 7, and thereafter slide 7 is lowered to bottom dead center while controlling the on / off of directional control valve 37.
• the controller 20 monitors the output of the pressure sensor 43 via the amplifier 45, The control valve 42 is controlled to increase the pressure of the knockout cylinder 15 until it becomes equal to the pressure of the main cylinder 5 ⁇ Then, the pressure of the knockout cylinder 15 is increased by the output of the pressure sensor 43.
• the controller 20 controls the pressure control valve 32 while monitoring the output of the pressure sensor 33 to decrease the pressure of the main cylinder 5.
• control device 20 controls the flow control valve 31, the directional control valve 37, and the pressure control valve 42, respectively. Then, the main cylinder 5 is moved to the upper limit position, the backup cylinder 13 and the knockout cylinder 15 are moved to the lower limit position, and one molding operation is completed.
• the present invention can be applied to, for example, rear extrusion molding as it is.
• the above shows an example in which the present invention is applied to plastic working using a chilled forging press.
• the present invention essentially improves the product accuracy by controlling the amount of die deformation uniformly.
• the cold forging press is shown as an example, and the present invention is widely applicable to plastic working in general. Yes o Industrial availability
• the slide is slowly lowered until the punch comes into contact with the blank, so that the die is prevented from being deformed due to the impact when the punch comes into contact with the blank, and the punch is brought into contact with the die.
• Product accuracy degradation due to die deformation due to impact upon contact is also prevented.
• both the fluid pressure for advancing the punch and the fluid pressure for advancing the support means in a state where the advancing of the punch is hindered by the support means are increased, and the fluid pressure for advancing the punch is applied to the blank.
• the pressure for advancing the support means is released, so that the advancing speed of the punch can be quickly increased to a target speed.
• the die since the blank is ejected in a state where pressure is applied to the blank, the die does not spring back until the blank is ejected. This can contribute to the accuracy of the molded product without damaging the product due to the backing.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Shaping Metal By Deep-Drawing, Or The Like (AREA)
• Forging (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

Family

ID=14014508

Family Applications (1)

Country Status (2)

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Citations (3)

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• 1991
  • 1991-07-18 WO PCT/JP1991/000958 patent/WO1993001905A1/ja not_active Application Discontinuation
  • 1991-07-18 EP EP91913072A patent/EP0549793A1/en not_active Withdrawn

Patent Citations (3)

Non-Patent Citations (1)

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