JPS61115626A - Locking mechanism with air cylinder and press lower die ascending descending device using air cylinder thereof - Google Patents

Abstract

PURPOSE:To make the lower die ascending and descending device of a press compact and simple in structure by using the air cylinder to equip with a locking mechanism as the driving source of the ascending and descending device of the lower die. CONSTITUTION:A piston 28 is tightly fitted freely slidably to the main body 20 of a cylinder. fixed bodies 35, 35 are provided by projecting the piston rod 24 connecting it on the prescribed position of the inner peripheral face of the cylinder main body 20 of the air cylinder 2 which is projected from the one end of the cylinder main body 20 and on the outer peripheral face of the piston 28. A device groove 31 is formed on either one part of the corresponding face with the movable body which is fixed to the projecting part of the piston rod 24 and a fitting aperture 32 on the other part respectively. It is so made that the locking body 34 which is possible to advance into and retreat from the fitting aperture 32 is fitted in the device groove 31 and locked unmovably with the advance of the piston 28 into the fitting aperture 32 which the locking body 34 corresponds to in the final end of its reciprocating stage and by the changeover of the pressurizing air for driving of the piston 28 to be fed to the cylinder main body 20 the locking body 34 retreats from the inside of the device groove 31 prior to the start of the reciprocating movement of the piston 28 and the lock is released.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an air cylinder equipped with a mechanism for locking a piston so that it cannot move at the end of its working stroke, and a press lower mold elevating device using the air cylinder.

Problems to be solved by conventional techniques and inventions, for example,
When deep drawing is performed sequentially using a multi-head press,
To take out the molded workpiece at each molding position from the lower mold and load it into the lower mold at the next molding position, the lower mold is fixed to the table and the workpiece transfer device is moved in two-dimensional directions in the horizontal and vertical directions. It is necessary to adopt one of two methods: to move the lower mold up and down, and to make the transfer device perform only horizontal movement.However, if the transfer device is made to perform two-dimensional movements, the drive mechanism becomes complicated. Not only will it become.

It has the disadvantage that it is difficult to increase the positioning accuracy and the machining accuracy decreases, and on the other hand, an extremely large load is applied to the lower mold, so in order to raise and lower it, a device with high rigidity that can withstand that load is required. However, it had the disadvantage of being significantly larger.

Purpose of the Invention The present invention was made based on the fact that a large load is applied to the lower mold only when the lower mold stops at an upper position, and a small driving force is sufficient during lifting and lowering movements. The first invention aims to provide an air cylinder equipped with a locking mechanism suitable as a drive source for this lifting device, and the second invention aims to raise and lower the lower die of a press using this air cylinder. The purpose is to provide a device.

Note that the use of the air cylinder according to the first invention is not limited to the lower die lifting device of a press, but is applicable to various air cylinders used when an excessive load is applied only when the piston is stopped. It is possible.

Embodiments Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings.

A first embodiment of the present invention is shown in FIGS. 1 to 3.

In the figure, reference numeral 1 denotes a press table, and an air cylinder 2 is mounted on the lower surface of the press table.
A lower mold 13 corresponding to an upper mold 14 fixed to a ram (not shown) is screwed onto the tip of a piston rod 24 which is fixed by a piston rod 2 and protrudes from the center hole 23 of the cylinder head 21 to the upper surface of the table 1.

The air cylinder 2 has a cylinder body 20 in which the cylinder head 21 is attached to the upper end of a pipe 25, and the cylinder cap 26 is attached to the lower end of the pipe 25, and the cylinder caps 26 and 25 are connected together by a port 27.
A piston 28 is fitted tightly and freely slidably therein, forming a lower chamber 20a and an upper chamber 20b below and above the piston 28, and the reduced diameter portion 30 at the lower end of the piston rod 24 is fitted into the center hole 29. and fixed by nut IO.

An annular device groove 31 is formed on the outer circumference of the piston 28 over the entire circumference, and a center hole 29 is formed in the inner end surface of this device groove 31.
Two sliding holes 32, 32 reaching 180° are formed at 180° intervals, and the reduced diameter portion 30 of the piston rod 24
A T-shaped ventilation hole 33 is formed in the cylinder body 20 to communicate each sliding hole 32, 32 with the lower chamber 20a of the cylinder body 20. As shown in FIG. 3, a pair of semicircular arc-shaped locking bodies 34 and 34 are tightly fitted into the device groove 31 of the piston 28 and freely slidable in the radial direction. .

Each sliding hole 32. is provided on the inner peripheral surface corresponding to the locking body 34.34.
A boss 35, 35 with a circular cross section is formed to fit tightly and freely into the 32, and a garter spring 37 is wound around a groove 36. A pair of locking bodies 34.
34 are urged to approach each other and retreat into the device groove 31, and chamfers 39 are formed on both upper and lower edges of the outer circumferential surface of each locking body 34, and chamfers 39 are formed on the outer circumferential surface and the chamfer 39.
A lining 38 made of Teflon or the like with excellent frictional properties is formed in the portion, and a lining 38 having excellent frictional properties such as Teflon is formed on the inner circumferential surface of the cylinder head 21. A fitting groove 41 of the same width is formed around the entire circumference of the piston 28 at a position corresponding to the device groove 31. Also.

The cylinder head 21 and the cylinder cap 26 are formed with an upper port 42 and a lower boat 43 that communicate with the upper chamber 20b and the lower chamber 20a, and each port 42, 43 is connected to a pressurized air supply source via a directional control valve (not shown). and the atmosphere.

Next, to explain the operation of this embodiment, as shown in FIG. When the workpiece W is supplied directly above the lower die 13 by the horizontal movement of a transfer device (not shown), the lower port 43 is connected to the pressurized air supply source by the operation of the directional control valve, and the lower chamber 20a of the cylinder body 20 is opened. Pressurized air is supplied to the piston rod 2, and the pressure causes the piston 28 to move toward the piston rod 2.
4 and the lower mold 13 start rising.

At this time, the pressurized air in the lower chamber 2Oa enters the sliding hole 32.32 of the piston 28 from the lower end surface of the piston rod 24 through the ventilation hole 33 and presses the boss 35.35, so that the locking body 34 and 34 are separated from each other against the elastic force of the garter spring 37.

It protrudes radially from the device hole 31 and is urged to be pressed against the inner circumferential surface of the cylinder body 20.
Since a lining 38 is formed on its outer peripheral surface,
The sliding resistance is small, and the piston 28 rises smoothly. When the piston 28 reaches the uppermost position, the cylinder head 2
When it comes into contact with the projection 40 on the inner top surface of 1, the locking body 34.34
As shown in FIG. 1, the locking body 34.34 is
Due to the pressing force of the pressurized air acting on the bosses 35 and 35, their tips are smoothly inserted into the fitting grooves 41 of the cylinder head 21, and the piston 28 is locked so that it cannot move up or down. At this time, the piston rod 24 reaches the uppermost position and the lower mold 13
supports the workpiece W held by the transfer device from below, and following the transfer device retracting to the side, the upper die 14 descends together with the ram, and presses the workpiece W between it and the lower die 13. The molding is performed, and the impact force of the ram that acts at this time is applied to the locking body 34. which is fitted into the device groove 31 and the fitting groove 41.
Since the receiver is stopped at 34, the piston 28 is held stationary without descending. When molding is completed and the upper mold 14 rises together with the ram.

When the transfer device enters from the side and holds the work W, and the lower boat 43 is communicated with the atmosphere by actuation of the directional control valve, the pressure in the lower chamber 20a of the cylinder body 20 decreases, and the piston 28 slides. Since the pressure inside the holes 32 and 32 also decreases, the locking bodies 34 and 34 are drawn together by the elastic force of the garter spring 37 and are pulled into the device groove 31 from inside the fitting groove 41.
When the upper port 42 is connected to a pressurized air supply source and the upper chamber 20 of the cylinder body 20 is retracted, the lock is released.
When pressurized air is supplied to b, the repiston 28 is lowered together with the piston rod 24 and the lower die 13 due to the pressure, and the workpiece W is transferred to the next process by the horizontal movement of the transfer device.

A second embodiment of the present invention shown in FIG. 4.5 differs from the first embodiment in that a communication hole 44 is formed between the tHa hole 32° 32 of the piston 28 and the ventilation hole 33 of the piston rod 24. A lower large-diameter hole 45 and an upper small-diameter hole 46 perpendicular to the communication hole 44 are formed concentrically so as to penetrate from the lower surface to the upper surface of the piston 28, and a conical seat surface is formed in a portion perpendicular to the communication hole 44. 47, and a conical valve body 49 that is in close contact with the seat surface 47 between a large diameter portion that fits tightly into the large diameter hole 45 and a small diameter portion that fits tightly into the small diameter hole 46.
The valve rod 48 formed with
A compression coil spring 52 is installed between the ring 51 fixed by a nut 50 to the upper end protruding from the upper surface of the piston 8, and the upper surface of the piston 28, and as shown in FIG. The valve rod 48 is pulled upward, and the valve body 49 comes into close contact with the seat surface 47 to close the communication hole 44. Therefore, as shown in FIG. 5, when the piston 28 is at the lowermost position and during the upward stroke until reaching the uppermost position, the sliding hole 32° 32 is located inside the lower chamber 2Oa of the cylinder body 20. The pressure of the locking body 34 is not applied.
．． 34 are drawn toward each other by the elastic force of the garter spring 37 and retreat into the device hole 31 of the piston 28, so that the outer circumferential surface thereof is not pressed against the inner circumferential surface of the cylinder body 20.

Therefore, as in the first embodiment, the locking body 34.3
The piston 28 operates smoothly even if the lining 38 is not formed on the outer peripheral surface of the piston 28. When the piston 28 approaches the uppermost position where it contacts the protrusion 40 on the inner top surface of the cylinder head 21, the upper end of the valve rod 48 contacts the inner top surface of the cylinder head 21 and is prevented from rising, and the compression coil spring 52 The valve rod 48 moves down relative to the piston 28 while elastically contracting, the valve body 49 separates from the seat surface 47, the communication hole 44 opens, and the pressurized air in the lower chamber 2Oa flows into the ventilation hole 33. From sliding hole 3
2.32, the pressure acts on the boss 35.35, and the locking bodies 34.34 are pushed away from each other against the elastic force of the garter spring 37, as shown in FIG. When the piston 28 reaches the uppermost position where it comes into contact with the protrusion 40 on the inner top surface of the cylinder head 21, the locking body 34
, 34 are fitted into the fitting groove 41 of the cylinder head 21, and as in the first embodiment, the piston 28, the piston rod 24 coupled thereto, and the lower die 13 are locked immovably, In this state, the upper die 14 is lowered together with the ram, and the workpiece W is formed. After completing the molding,
When the lower port 43 is communicated with the atmosphere by the operation of the directional control valve, the pressure in the lower valve chamber 20a and the sliding hole 32.32 decreases, and the pressure acting on the boss 35.35 is released, and the locking body 34.34i The elastic force of the garter spring 37 retracts into the device groove 31 to release the lock.Next, when pressurized air is supplied from the upper port 42 to the upper chamber 20b, the pressure causes the piston 28 to move toward the piston rod. 24 and the lower mold 13, and at the beginning of the downward stroke, the upper end of the valve rod 48 separates from the inner top surface of the cylinder head 21, and is moved relative to the piston 28 by the elastic expansion force of the compression coil spring 52. The valve body 49 comes into close contact with the seat surface 47 and closes the communication hole 44, returning to the state shown in FIG. 5.

The third embodiment of the present invention shown in FIGS. 6 and 7 is similar to the first embodiment described above. Contrary to the second embodiment, a device groove 31 is formed on the inner circumferential surface of the cylinder head 21, and two sliding holes 32, 32 are formed on the rear end surface of the device groove 31, as shown in FIG. A pair of locking bodies 34.3 having an arcuate shape, a lining 38 formed on the inner peripheral surface, and chamfers 39.39 on both upper and lower edges thereof.
4 into the device groove 31, and the boss 35 with a circular cross section protruding from the outer peripheral surface of each locking body 34 is tightly fitted into each sliding hole 32, and the corresponding locking bodies 34 and 34 are Compression coil springs 53 and 53 are interposed between the end faces of the piston 28, and the elastic force of the springs 53 and 53 bias the piston 28 in the direction of moving away from each other and retracting into the device groove 31.
A fitting groove 41 is formed on the outer peripheral surface corresponding to the cylinder body 20, and each sliding hole 32 and the lower chamber 20a of the cylinder body 20 are connected by a ventilation pipe 54, and pressurized air is supplied to the lower chamber 20a. When this occurs, the piston 28 rises due to the pressure, and the pressure passes through the ventilation pipe 54 and into the slide hole 32.
32 and presses the boss 35.35, the locking body 34.34 is pressed against the outer peripheral surface of the piston 28,
As shown by the solid line in FIG. 6, when the piston 28 reaches the uppermost position and the fitting groove 41 aligns with the device groove 31, the inner circumference of the locking body 34°34 fits into the fitting groove 41. , the piston 28 is locked immovably, and when the lower chamber 20a is opened to the atmosphere by actuation of the directional control valve, the sliding holes 32, 32
The internal pressure also decreases, and the locking bodies 34.34 are separated from each other and retreated into the device groove 31 due to the elastic expansion force of the compression coil springs 53.53, and the lock is released, so that the upper chamber 20b is pressurized. By supplying air, it is lowered to the lower position shown by the chain line in FIG.

A fourth embodiment of the invention, shown in FIG. 8.9, includes a piston 28
Similar to the first and second embodiments, the locking bodies 34 and 34 are fitted into the device groove 31 formed on the outer periphery of the device, and are retracted into the device groove 31 by the elastic force of the garter spring 37. The operating rod 56 is tightly and slidably fitted into the guide hole 55 penetrating the upper and lower surfaces of the piston 28, and is inserted into the guide groove 59 connected to the upper part of the guide hole 55. .

An engagement piece 57 protruding from the center of the operating rod 56 is accommodated, and a boss protruding from the locking body 34 is housed in the sliding hole 32 formed to communicate the device groove 31 and the guide groove 59. 35 is inserted, and the upward slope 60 formed at the tip thereof and the downward slope 58 formed on the engagement piece 57 come into contact with each other.

A fitting blind hole 61 is formed in the inner top surface of the cylinder head 21 directly above the operating rod 56, and a diameter-reducing step 62 is formed at the opening at the lower end, into which a small piston 63 can tightly and freely slide. A first compression coil spring 6 with a small spring constant is fitted between the lower surface of the collar 64 and the upper end of the operating rod 56.
5 is installed, and a small piston is installed in the fitting hole 61. 63
A second compression coil spring 66 with a large spring constant is attached to press the upper surface of the fitting hole 61, and the fitting hole 61 is opened to the atmosphere through a ventilation hole 67.

To explain the operation of this embodiment, when pressurized air is supplied to the lower chamber 20a and the piston 28 rises from the lower position shown in FIG. 9, the first compression coil spring 65 is gradually compressed. The elastic expansion force increases, and the slope 5 of the engagement piece 57
8 increases the force pushing the slope 60 of the boss 35 and overcomes the elastic force of the garter spring 37, the locking bodies 34 and 34 rise while being pressed against the inner circumferential surface of the cylinder body 20, as shown in FIG. When the piston 28 reaches the uppermost position, the operating rod 56 descends and the outer circumferences of the locking bodies 34, 34 fit into the fitting grooves 41, locking the piston 28 and piston rod 24 so that they cannot rise or fall. be done. Next, the lower chamber 20
a is opened to the atmosphere and the upper chamber 20b is connected to a source of pressurized air.

A first compression coil spring 65 is provided on the lower surface of the small piston 63.
In addition to the elastic expansion force, the pressure of the pressurized air in the upper chamber 20b acts to overcome the elastic expansion force of the second compression coil spring 66,
By elastically contracting this, the small piston 63 rises inside the fitting hole 61 as shown by the chain line in FIG. 8, and the first compression coil spring 6
5 expands and its elastic expansion force decreases, so that the locking body 34.
34 is a slope 60 due to the elastic force of the garter spring 37.
58 pushes up the operating rod 56 and retreats into the device groove 31, the lock is released and the piston 28 and piston rod 24 descend. Note that the small piston 63 is connected to the second compression coil spring 6 by opening the upper chamber 20b to the atmosphere.
Due to the elastic expansion force of 6, it descends to the original position where it abuts against the diameter-reducing step portion 62.

The embodiment of the present invention shown in FIG. 10 is a modification of the fourth embodiment, in which the second compression coil spring 66 is removed.
The fitting hole 61 is configured to communicate with the lower chamber 20a through a ventilation pipe 68, and during the upward stroke of the piston 28, pressurized air in the lower chamber 2Oa acts on the upper surface of the small piston 63 to hold it in the lower position. When the lower chamber 20a is opened to the atmosphere, the first compression coil spring 65 pushes up the small piston 63 and expands, and the locking body 34 retreats into the device groove 31 due to the reduction in its elastic expansion force. 6 The fifth embodiment of the present invention shown in FIG.
A cylindrical fixing body 70 is integrally fixed to the outer end surface of the cylinder head b by bolts C, and the protruding portion of the piston rod d protruding from the cylinder head b is tightly fitted to the inner peripheral surface of the fixing body 70. The thick disc-shaped movable body 71 is inserted into the center hole 78.
A pair of locking bodies 75 and 75 each having a semicircular arc shape are fitted into the device groove 72 formed on the outer peripheral surface of the movable body 71 and fixed by a nut 77. The elastic force of the garter spring 79 wound around the outer periphery of the garter springs 79 urges them toward each other, and the bosses 76 protruding from the inner peripheral surface of each locking body 75 are inserted from the inner end surface of the device groove 72 into the center hole 78. A ventilation hole 74 is formed in the piston rod d to tightly fit into the transparent sliding hole 73, and communicates the lower chamber e of the air cylinder a with the sliding hole 73. , a fitting groove 80 of the same width is formed on the inner peripheral surface of the fixed body 70 corresponding to the device groove 72 of the movable body 71, and its operation is the same as that of the first embodiment.

In this embodiment, the locking mechanism of the first embodiment is provided on the outer surface of the cylinder head of a conventionally known air cylinder, but the structure of this locking mechanism is the same as in the second to fourth embodiments. You may replace it with

Structure and effects of the invention As specifically explained by the above embodiments.

An air cylinder according to a first aspect of the present invention has a piston tightly and slidably fitted into a cylinder body, and a piston rod connected to the piston protrudes from at least one end of the cylinder body. A corresponding surface between a predetermined position on the inner circumferential surface of the cylinder body and the outer circumferential surface of the piston, or a fixed body protruding from the end face of the one end side of the cylinder body and a movable body fixed to the protruding part of the piston rod. A device groove is formed in one of the device grooves, and a fitting groove is formed in the other, and a locking body capable of entering and retracting into the fitting groove is fitted into the device groove, and the piston is moved back and forth. At the end of the movement stroke, the locking body enters the corresponding fitting groove and is locked so that it cannot move, and the piston is moved back by switching the pressurized air for driving the piston supplied to the cylinder body. The gist is that the locking body retreats into the device groove to release the lock prior to the start, and the locking body is fitted at the end of the forward movement of the piston. It is fitted into the groove and locked so that it cannot be raised or lowered, and the load acting on the piston rod is stopped by the locking body, so by increasing the thickness of the locking body, it can withstand large loads, and Since the locking body advances and retreats in a direction perpendicular to the direction of load application when the piston is at rest, a large force is not required to drive it.

Furthermore, since the locking body is retracted into the device groove by switching the pressurized air for driving the piston, there is no need for any other driving source, and the structure can be made small and simple. play. In addition, a lower mold elevating device of a press according to a second invention of the present invention uses the air cylinder according to the first invention as a lower mold elevating device, and the lower mold is moved to an upper molding position. Since the workpiece can be raised and lowered to the lower retracted position, the workpiece transfer device only needs to move in the horizontal direction.The structure is simple, the positioning accuracy is high, and the large loads that are applied during molding can be avoided. The receiver can be stopped by the locking body, and there is an effect that press forming can be performed reliably without using any other locking device.

[Brief explanation of the drawing]

FIG. 1.2 is a sectional view showing the operation of the first embodiment of the present invention;
Fig. 3 is a perspective view of the locking body, Figs. 4 and 5 are partially enlarged sectional views showing the operation of the second embodiment of the present invention, and Fig. 6 is a part of the third embodiment of the present invention. , FIG. 7 is a perspective view of the locking body, FIG. 8-9 is a partial enlarged sectional view showing the operation of the fourth embodiment of the present invention, and FIG. 10 is a cross-sectional view of a modification thereof. 11 are cross-sectional views of a fifth embodiment of the present invention. 1: Table 2: Air cylinder 13: Lower mold 14
: Upper mold 21 Niji cylinder head 24: Piston rod 20 Niji cylinder body 20a: Lower chamber 20b: Upper chamber 28: Piston 31: Device groove 32: Translation hole 33
: Ventilation hole 34: Locking body 35: Boss 37: Garter spring 41: Fitting groove 44: Communication hole 47: Seat surface 48: Valve rod 49: Valve body 53: Compression coil spring 5
5: Guide hole 56: Operating rod 57: Engagement piece 58.60:
Slope 61: Fitting hole 63; Small piston 65: First compression coil spring 66: Second compression coil spring 70:
Fixed body 71: Movable body 72: Device groove 73: Sliding hole
75: Locking body 76: Boss 79: Garter spring
80: Fitting groove a: Air cylinder b Niji cylinder head d: Piston rod W: Work applicant CKD Co., Ltd. agent Patent attorney Hiroki Noguchi 2 times'$ 1 time 5TijJ 4 figures 9 figures 8 times

Claims (1)

[Scope of Claims] 1. An air cylinder having a piston tightly and slidably fitted into the cylinder body, and a piston rod connected to the piston protruding from at least one end of the cylinder body. either a predetermined position on the circumferential surface and the outer circumferential surface of the piston, or a corresponding surface between a fixed body protruding from the end face of the one end side of the cylinder body and a movable body fixed to the protruding portion of the piston rod. A device groove is formed on the other side, and a fitting groove is formed on the other side, and a locking body capable of entering and retracting into the fitting groove is fitted in the device groove, and the piston is formed at the end of its forward stroke. The locking body enters the corresponding fitting groove and is locked so that it cannot move, and the pressurized air supplied to the cylinder body for driving the piston is switched, thereby causing the piston to move back. An air cylinder equipped with a locking mechanism characterized in that the locking body is configured to retreat into the device groove to release the lock.2 A piston is tightly and slidably fitted into the cylinder body. , a piston rod connected to the piston is placed at a predetermined position on the inner circumferential surface of the cylinder body of the air cylinder protruding from at least one end of the cylinder body and on the outer circumferential surface of the piston, or on the end surface of the one end side of the cylinder body. A device groove is formed in one of the corresponding surfaces of the protruding fixed body and a movable body fixed to the protruding portion of the piston rod, and a fitting groove is formed in the other, and a groove is formed in the device groove in the fitting groove. A locking body that can enter and retreat into the piston is fitted, and at the end of the forward stroke of the piston, the locking body enters the corresponding fitting groove and is immovably locked, and the piston is locked so that it cannot move. Pressing an air cylinder configured such that, by switching the pressurized air for driving the piston supplied to the main body, the locking body retreats into the device groove and the lock is released prior to the start of the backward movement of the piston. A lower die lifting device for a press, characterized in that the piston rod is mounted on a table with the piston rod facing upward, and a lower die corresponding to an upper die fixed to a ram is fixed to the tip of the piston rod.