Press Equipment

Abstract

To maintain a pressure inside a balance cylinder even at a bottom dead center for adjusting the die height of the slide at the same balance pressure as the top dead center of a slide.SOLUTION: In a pressing apparatus 10, an exhauster-equipped regulator 72 of a pressure regulating unit 70 supplies pressure-regulated air for a balanced pressure corresponding to the weights of a slide 20 and an upper mold 30, to a balance cylinder 50 that suspends and supports the slide 20. When the volume of the cylinder 51 decreases due to the movement of the slide 20 from the top dead center to the bottom dead center, the pressure-regulated air increases inside a cylinder 51 of the balance cylinder 50 from the balanced pressure. The exhauster-equipped regulator 72 releases air by an amount corresponding to the increased pressure from a relief hole 75 to the atmosphere via an opened solenoid valve 76. During releasing the air by the amount corresponding to the increased pressure, the exhauster-equipped regulator 72 maintains the supply of the pressure-regulated air for the balanced pressure with respect to the balance cylinder 50.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a press machine. [Background technology]

[0002] Patent Document 1 describes a technique in which a slide to which an upper die of a press is attached is supported in a balanced manner by a balance cylinder connected to the slide, and the slide is raised and lowered in a perfectly balanced support state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 62-168700 Summary of the Invention [Problem to be solved by the invention]

[0004] The internal pressure of the balance cylinder is adjusted to a balanced pressure at the top dead center of the slide with the upper die attached to the slide.

[0005] If the internal pressure of the balance cylinder is adjusted to the balance pressure at the top dead center of the slide, the volume of the cylinder chamber will be smaller at the bottom dead center of the slide than at the top dead center, so the internal pressure of the balance cylinder will increase, resulting in an overbalance state that is higher than the balance pressure.

[0006] At the bottom dead center of the slide, the position of the slide is adjusted in the vertical direction to adjust the die height of the slide to which the upper die is attached. If the slide is adjusted in an overbalanced state, the load on the parts that move during the adjustment increases. [Means for solving the problem]

[0007] A press apparatus according to one aspect of the present invention comprises: a slide on which the upper die of the die is attached and which moves up and down between the top dead point and the bottom dead point; a balance cylinder that suspends and supports the slide, to which the upper die is attached, in a balanced state at the top dead center by air at a balance pressure that is supplied to the inside of the cylinder; a regulator for supplying air at the balance pressure to the inside of the cylinder; a pressure reducing circuit that releases the increased air pressure to the outside of the cylinder via the regulator when the air pressure inside the cylinder exceeds the balance pressure; Equipped with.

[0008] In one embodiment of the present invention, air at a balanced pressure is supplied from a regulator to the inside of the balance cylinder. The balance cylinder to which the air at the balanced pressure is supplied suspends and supports the slide and the upper die attached to the slide in a balanced state at the top dead center of the slide. When the balance cylinder is in a balanced state, the load due to the total weight of the slide and the upper die and the load in the lifting direction applied to the slide from the balance cylinder are balanced.

[0009] At the bottom dead center of the slide, an adjustment is made to the slide. In the adjustment, the position of the slide relative to the bolster to which the lower die is fixed is adjusted in the direction in which the slide moves up and down. During the adjustment, a load is applied to the parts that move in conjunction with the adjustment.

[0010] At the bottom dead center of the slide, the volume of the balance cylinder is smaller than at the top dead center of the slide. At the bottom dead center of the slide, the pressure inside the cylinder increases beyond the balance pressure at the top dead center of the slide. If the pressure inside the cylinder remains increased, the load on the parts that move with the adjustment will remain increased. If the load on the parts that move with the adjustment increases, wear on these parts will be accelerated.

[0011] In one embodiment of the present invention, when the air pressure inside the cylinder exceeds the balance pressure, the increased air pressure is released to the outside of the cylinder by the pressure reducing circuit. By releasing the increased air pressure, the pressure inside the cylinder returns to the balance pressure. When the pressure inside the cylinder returns to the balance pressure, the balance cylinder suspends and supports the slide with the upper die attached in a balanced state at the bottom dead center. Effect of the Invention

[0012] According to a press equipment according to one aspect of the present invention, even when the slide is moved to the bottom dead point where the die height of the slide is adjusted, the internal pressure of the balance cylinder can be maintained at the same balance pressure as that at the top dead point of the slide. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is an explanatory diagram showing a schematic configuration of a portion involved in raising and lowering a slide of a press apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram that shows a schematic configuration of a comparative example that can be considered as the configuration of the portion involved in raising and lowering the slide in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The same or equivalent parts or components are designated by the same reference numerals throughout the drawings.

[0015] The following embodiments are examples of devices for embodying the technical idea of ​​the present invention. The technical idea of ​​the present invention does not limit the material, shape, structure, arrangement, function, etc. of each component to those described below.

[0016] A press apparatus according to an embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 shows the configuration of the main parts of the press apparatus. The press apparatus 10 in Fig. 1 has a slide 20, an upper die 30, a bolster to which a lower die is attached (none of which are shown), a connecting rod 40, and a balance cylinder 50. The press apparatus 10 further has a lock mechanism 44 and an adjustment mechanism 60 for the connecting rod 40, a pressure adjustment unit 70 for the balance cylinder 50, and a compressed air supply source 80.

[0017] The slide 20 moves up and down between the top dead center and the bottom dead center. An upper die 30 of a metal mold is attached to a lower surface 21 of the slide 20. A connecting rod 40 and a balance cylinder 50 are connected to an upper portion of the slide 20.

[0018] The connecting rod 40 transmits the power to raise and lower the slide 20 from a power source (not shown) to the slide 20, and has an upper rod 41, which is an element on the power side (power source side), and a lower rod 42, which is an element on the slide side (slide 20 side).

[0019] The upper rod 41 is rotatably connected to, for example, an eccentric portion of a crankshaft (not shown). The crankshaft can be rotated by a power source such as a servo motor. The lower rod 42 is swingably connected to an upper portion of the slide 20. The lower rod 42 can be swingably connected to the slide 20 via, for example, a ball joint portion 43 at the lower end of the lower rod 42.

[0020] The upper rod 41 and the lower rod 42 are connected via an adjustment mechanism 60 of the connecting rod 40. The adjustment mechanism 60 can be configured using a male thread portion 61 and a female thread portion 62. In this embodiment, the lower rod 42 is provided with the male thread portion 61, and the upper rod 41 is provided with the female thread portion 62.

[0021] The upper rod 41 and the lower rod 42 can be connected in the power transmission direction X from the power source to the slide 20 by screwing the male thread portion 61 into the female thread portion 62. The amount of screwing of the male thread portion 61 into the female thread portion 62 can be adjusted by the relative movement caused by the rotation of the lower rod 42 with respect to the upper rod 41.

[0022] In the adjustment mechanism 60, the connecting rod 40 can be extended or retracted by adjusting the amount of engagement of the male thread portion 61 with the female thread portion 62. By extending or retracting the connecting rod 40, the height (die height) of the slide 20 relative to a bolster (not shown) to which the lower die of the die is fixed can be adjusted.

[0023] The direction in which the connecting rod 40 extends and contracts can be a direction that includes, as a vector component, the direction X of power transmission in the connecting rod 40. In this embodiment, the direction in which the connecting rod 40 extends and contracts is set to coincide with the direction X of power transmission.

[0024] The lower rod 42 can be rotated relative to the upper rod 41 by, for example, power transmitted from a servo motor (not shown) via a worm gear to the lower rod 42. In this embodiment, the extension and contraction movement of the connecting rod 40 caused by the rotation of the lower rod 42 relative to the upper rod 41 can be locked by a lock mechanism 44.

[0025] The lock mechanism 44 may be, for example, an air cylinder 45. The air cylinder 45 may be, for example, a push-type single-acting air cylinder. A compressed air supply source 80 is connected to the head side of the air cylinder 45 via a normally closed solenoid valve 46 of the lock mechanism 44.

[0026] The solenoid valve 46 is opened by the input of a lock signal (not shown) to turn the solenoid on when the extension and contraction movement of the connecting rod 40 by the adjustment mechanism 60 is locked by the lock mechanism 44. When the solenoid valve 46 is opened, compressed air from the supply source 80 is supplied to the air cylinder 45, and the piston rod 47 of the air cylinder 45 is pushed out of the cylinder.

[0027] The pushed-out piston rod 47 interferes with, for example, the worm or worm wheel of the worm gear described above, rendering the lower rod 42 unable to rotate, thereby locking the extension and retraction movement of the connecting rod 40.

[0028] When the lock mechanism 44 is used to release the extension and retraction of the connecting rod 40, the solenoid valve 46 is closed by the termination of the input of a lock signal (not shown) and the solenoid is turned off. When the solenoid valve 46 is closed, the air cylinder 45 is cut off from the supply source 80 and the compressed air in the air cylinder 45 is released to the atmosphere via the closed solenoid valve 46. When the compressed air in the air cylinder 45 is released to the atmosphere, the piston rod 47 is pulled into the cylinder by the spring force of the return spring 48.

[0029] The retracted piston rod 47 retreats to a position where it does not interfere with the worm or worm wheel of the worm gear, allowing the lower rod 42 to rotate and unlocking the extension and retraction of the connecting rod 40. This unlocking puts the press 10 in a state where the die height of the slide 20 can be adjusted by the extension and retraction of the connecting rod 40.

[0030] The balance cylinder 50 suspends and supports the slide 20. The balance cylinder 50 may be composed of one cylinder, or may be composed of two or more cylinders. In this embodiment, two balance cylinders 50, 50 are arranged in a pair on the left and right above the slide 20. Each balance cylinder 50 can be composed of, for example, a retractable single-acting air cylinder.

[0031] Each balance cylinder 50 has a piston 52 that moves inside the cylinder 51, and a piston rod 53 attached to the piston 52. The lower end of the piston rod 53 extending outside the cylinder 51 is connected to the upper part of the slide 20.

[0032] Each balance cylinder 50 suspends and supports the slide 20 via a piston rod 53 by pressure received by the pressure-receiving surface of the piston 52 on the slide 20 side from compressed air supplied into the inside of the cylinder 51 from a port (not shown) provided on the rod side of the cylinder 51. When the total pressure of the air pressures received by the pistons 52 of the balance cylinders 50 is the balance pressure, the slide 20 at the top dead center to which the upper die 30 is attached is suspended and supported in a balanced state by the pair of balance cylinders 50, 50.

[0033] The balance pressure is the total pressure value received by the pressure-receiving surface of the piston 52 of each cylinder 51 when a load in the lifting direction that balances the total weight of the upper die 30 and the slide 20 is applied to the slide 20 at the top dead center with the upper die 30 attached. The balance pressure is a value according to the upper die 30 attached to the slide 20.

[0034] A common pressure regulating unit 70 is connected to the ports of the cylinders 51 of each balance cylinder 50. In the pressure regulating unit 70, compressed air from a supply source 80 passes through a filter 71, has its pressure regulated by an exhaust regulator 72, and is supplied to the ports of the cylinders 51 of each balance cylinder 50 via an air tank 73. The exhaust regulator 72 regulates the pressure of the compressed air from the supply source 80 to a pressure that corresponds to a set pressure output from a pilot regulator 74 of the pressure regulating unit 70.

[0035] The exhaust regulator 72 adjusts the pressure of the compressed air on the primary side input from the supply source 80 to a pressure corresponding to the set pressure from the pilot regulator 74, and outputs it to the air tank 73 from the secondary side as regulated air.

[0036] The exhaust regulator 72 can be configured using, for example, a high relief regulator. The exhaust regulator 72 has a check valve (not shown). When the pressure of the regulated air on the secondary side increases beyond the pressure corresponding to the set pressure from the pilot regulator 74, the check valve opens and receives the increased air into the housing of the exhaust regulator 72. The received increased air can be released to the outside of the exhaust regulator 72 from, for example, a relief hole 75 in the housing. The compressed air on the primary side does not flow into the secondary side through the check valve. The relief hole 75 of the exhaust regulator 72 is connected to the atmosphere via a normally open solenoid valve 76 of the pressure adjustment unit 70.

[0037] The solenoid valve 76 operates in synchronization with the locking and unlocking of the connecting rod 40 by the locking mechanism 44. Like the solenoid valve 46 of the locking mechanism 44, the solenoid valve 76 is turned on when a lock signal is input and turned off when the input of the lock signal ends. When the solenoid valve 76 is closed by the solenoid on, it blocks the relief hole 75 of the exhaust regulator 72 from the atmosphere. When the solenoid valve 76 is opened by the solenoid off, it connects the relief hole 75 to the atmosphere.

[0038] When the regulated air on the secondary side of exhaust regulator 72 is increased beyond a pressure corresponding to the set pressure, solenoid valve 76 can release the increased air pressure from relief hole 75 to the atmosphere while connecting rod 40 is unlocked. While connecting rod 40 is locked, solenoid valve 76 stops the release of the increased air pressure. The check valve of exhaust regulator 72, relief hole 75, and solenoid valve 76 can form a pressure reducing circuit.

[0039] The pilot regulator 74 can set the pressure (set pressure) of the regulated air output from the secondary side to the exhaust regulator 72 to any pressure, for example, by operating a pressure adjustment screw (not shown). By adjusting the set pressure of the pilot regulator 74, the balance pressure of the regulated air supplied from the exhaust regulator 72 to each balance cylinder 50 can be increased or decreased to a value according to the weight of the slide 20 and the upper die 30 attached to the slide 20.

[0040] An abnormal increase in the air pressure in the air tank 73 can be prevented by opening the relief valve 77 of the pressure adjustment unit 70 connected to the air tank 73. The air pressure when the relief valve 77 is opened can be set to a pressure higher than the regulated air pressure when the check valve of the exhaust regulator 72 is opened, for example.

[0041] In the press equipment 10 of this embodiment, while the extension and retraction operation of the connecting rod 40 is locked, the pressure of the pressure regulating air supplied to the pair of balance cylinders 50, 50 is adjusted to a balance pressure with the slide 20 to which the upper die 30 is attached being positioned at the top dead center. After adjustment to the balance pressure, the slide 20 and the upper die 30 are suspended and supported in a balanced state by the pair of balance cylinders 50, 50.

[0042] After adjustment to the balance pressure, the lock on the extension and contraction movement of the connecting rod 40 is released. After the lock is released, the slide 20 to which the upper die 30 is attached is moved from the top dead center to the bottom dead center, and the die height of the slide 20 is adjusted at the bottom dead center.

[0043] When the volume of the cylinder 51 of the balance cylinder 50 decreases and the regulated air inside the cylinder 51 increases from the balance pressure while the slide 20 is moving from the top dead center to the bottom dead center, the increased air flows into the housing through the check valve of the exhaust regulator 72. The increased air that has flowed in is released to the atmosphere from the relief hole 75 of the exhaust regulator 72 via the solenoid valve 76, which is opened by unlocking the connecting rod 40.

[0044] The exhaust regulator 72 maintains the supply of regulated air at the balance pressure to the balance cylinder 50, even while releasing the increased pressure air. The slide 20 and the upper die 30 are suspended and supported in a balanced state by the pair of balance cylinders 50, 50, even while the slide 20 moves from the top dead center to the bottom dead center.

[0045] After the die height of the slide 20 is adjusted, the extension and contraction of the connecting rod 40 is locked and the press operation is started. While the connecting rod 40 is locked, the solenoid valve 76 is closed, so that even if the pressure-adjusting air inside the cylinder 51 increases from the balance pressure, the release of the increased air to the atmosphere is stopped.

[0046] In this embodiment, a regulator 72 with exhaust is used to supply regulated air at a balance pressure to the balance cylinder 50. The supply of regulated air at a balance pressure to the balance cylinder 50 can also be performed using a regulator 172 with a variable regulated pressure, for example, as in a pressure adjustment unit 170 of a comparative example shown in Fig. 2. The regulator 172 can adjust the compressed air supplied from the supply source 80 via a filter 71 to a balance pressure by, for example, operating a pressure adjustment screw, and supply the air to the air tank 73 and the cylinder 51 of the balance cylinder 50.

[0047] When regulator 172 is used, if the regulated air inside cylinder 51 increases from the balance pressure, there is no way to return the regulated air in cylinder 51 to the original balance pressure other than increasing the pressure to an abnormal pressure and opening relief valve 77.

[0048] When the regulator 172 is used, when the slide 20 is moved from the top dead center to the bottom dead center after adjustment to the balance pressure, the regulated air in the cylinder 51 increases beyond the balance pressure. When the regulated air in the cylinder 51 increases in pressure, the load in the lifting direction applied to the slide 20 by the pair of balance cylinders 50, 50 becomes excessive, resulting in an overbalance state.

[0049] If the die height adjustment of the slide 20 is performed in an overbalanced state after the slide 20 has moved to the bottom dead center, a load greater than that in the balanced state is applied to the male thread portion 61 and the female thread portion 62 of the adjustment mechanism 60. Similar to the adjustment mechanism 60, a load greater than that in the balanced state is also applied to the worm and worm wheel of the worm gear (not shown), the servo motor, and other parts that operate during die height adjustment. Parts to which a load greater than that in the balanced state is applied will experience accelerated wear.

[0050] In the press equipment 10 of this embodiment, by using the regulator with exhaust 72 shown in FIG. 1, the pressure regulated air in the cylinder 51 can be kept at a balanced pressure even during adjustment of the die height, and it is possible to prevent the application of excessive load to moving parts during adjustment, which would promote wear.

[0051] The set pressure input to the exhaust regulator 72 may be changed directly by the exhaust regulator 72. For example, if a pressure-changing configuration such as a pressure adjusting screw is provided at the input portion of the set pressure of the exhaust regulator 72, the set pressure can be changed in the exhaust regulator 72. When the set pressure is changed by the exhaust regulator 72, the pilot regulator 74 used to change the set pressure in this embodiment becomes unnecessary.

[0052] The advantage of using the pilot regulator 74 to change the set pressure of the exhaust regulator 72 as in this embodiment is that high accuracy can be maintained when changing the set pressure to a target pressure.

[0053] For example, if the set pressure is changed directly using exhaust regulator 72, there is a possibility that some of the air at the set pressure input to exhaust regulator 72 will leak into relief hole 75 inside exhaust regulator 72. If the air at the set pressure leaks into relief hole 75, air will leak out of exhaust regulator 72 from relief hole 75, and even if the change operation is performed correctly, the set pressure may not be changed correctly to the target pressure. If the changed set pressure is not accurate, the pressure of the regulated air output from the secondary side of exhaust regulator 72 cannot be changed to the correct pressure.

[0054] With pilot regulator 74, which does not have a relief hole, there is no need to worry about air at the set pressure leaking from the relief hole, as with exhaust regulator 72. If the set pressure of exhaust regulator 72 is changed using pilot regulator 74, the set pressure can be correctly changed to the target pressure in response to the change, and high precision in adjusting the pressure of the air supplied to each balance cylinder 50 can be maintained.

[0055] In this embodiment, the solenoid valve 76 is opened in synchronization with the end of input of the lock signal that locks the extension and contraction movement of the connecting rod 40, and is closed in synchronization with the resumption of input of the lock signal. By synchronizing the operation of the solenoid valve 76 with the lock signal, it is possible to switch between a state in which the increased air pressure cannot be released to the atmosphere from the relief hole 75 of the exhaust regulator 72 and a state in which the increased air pressure can be released in synchronization with the locking and unlocking of the lock mechanism 44. This switching ensures that the increased air pressure in the balance cylinder 50, which is increased while the slide 20 is moving from the top dead center to the bottom dead center, can be released to the atmosphere.

[0056] In order to open the solenoid valve 76 while the slide 20 is moving from the top dead center to the bottom dead center, the operation of the solenoid valve 76 may be synchronized to a signal or operation other than the lock signal.

[0057] The check valve and relief hole 75 of exhaust regulator 72, which are components of the pressure reducing circuit, may be configured as elements separate from exhaust regulator 72, like solenoid valve 76. For example, if a regulator that integrates the check valve and relief hole 75, such as a high relief regulator, is used, the main parts of the pressure reducing circuit can be easily configured with elements that the regulator has. [Explanation of symbols]

[0058] 10 Press Equipment 20 Slides 30 Upper mold 40 Connecting rod 41 Upper rod (power side element) 42 Lower rod (slide side element) 60 Adjustment mechanism 44 Locking mechanism 72 Regulator with exhaust (regulator, pressure reducing circuit) 74 Pilot Regulator 75 Relief hole (pressure reducing circuit) 76 Solenoid valve (pressure reducing circuit) X Transmission direction

Claims

1. a slide on which the upper die of the die is attached and which moves up and down between the top dead point and the bottom dead point; a balance cylinder that suspends and supports the slide, to which the upper die is attached, in a balanced state at the top dead center by air at a balance pressure that is supplied to the inside of the cylinder; a regulator for supplying air at the balance pressure to the inside of the cylinder; a pressure reducing circuit that releases the increased air pressure to the outside of the cylinder via the regulator when the air pressure inside the cylinder exceeds the balance pressure; a connecting rod for transmitting power for raising and lowering the slide to the slide; an adjustment mechanism for extending and retracting the connecting rod; a lock mechanism that locks the extension and contraction operation of the connecting rod by the adjustment mechanism; Equipped with The pressure reducing circuit switches between releasing and stopping the release of the increased pressure air in synchronization with the unlocking and locking of the extension and retraction operation of the connecting rod by the locking mechanism. Press equipment.

2. A press equipment as described in claim 1, wherein the pressure reducing circuit releases the pressurized air while the extension and contraction movement of the connecting rod is unlocked by the locking mechanism, and stops releasing the pressurized air while the extension and contraction movement of the connecting rod is locked by the locking mechanism.

3. 3. The press machine according to claim 1, wherein the regulator and the pressure reducing circuit constitute a single regulator with exhaust.

4. 4. The press machine according to claim 3, further comprising a pilot regulator that supplies air at a set pressure corresponding to the balance pressure to the exhaust regulator, wherein a value of the balance pressure is increased or decreased by adjusting the set pressure in the pilot regulator.

Images