JPH06189Y2 - Fluid pressure circuit for cylinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a hydraulic circuit for a cylinder arranged in a transfer press, and more specifically, to a brake cylinder for locking and unlocking a lift cylinder. The present invention relates to a fluid pressure circuit for a cylinder for supplying.

[Conventional technology]

Generally, in a transfer press, a feed bar conveys a work by a series of operations including clamp, lift, advance, down, unclamp, and return. Among them, the lift-down mechanism of the feed bar that performs the lift-down operation is a structure in which a follower is brought into contact with a lift cam that interlocks with a crankshaft, and the motion of this follower is transmitted to the feed bar via a lever, a rod, and an interlocking device. The ones are common. In addition, this lift-down mechanism is equipped with a lift cylinder that biases the cam follower to the lift cam on the rod, and a brake cylinder that prevents the rod from going up and down so that the feed bar does not go down due to its own weight when the press is stopped. There are different configurations.

By the way, if foreign matter is caught between the feed bar and the bolster below the feed bar, and the lowering of the feed bar is blocked, mechanical parts such as the rod are overloaded, and
Damage to the mechanical parts may occur. Therefore, conventionally, in the lift-down mechanism, an overload safety device is incorporated to turn off the press power source to stop the operation of the press when the mechanical parts are overloaded. When the safety device is activated and the press power is turned off, the press operation is stopped and the brake cylinder is actuated to prevent the lift cylinder from moving.

[Problems to be solved by the invention]

However, in order to prevent damage to the feed bar, even if the pinched foreign matter is removed, since the movement of the lift cylinder is blocked by the brake cylinder, the feed bar does not move. Moreover, since the press power source is turned off, the fluid cannot be supplied to the brake cylinder. Therefore, conventionally, in such a case, development of a cylinder fluid pressure circuit capable of raising and lowering the feed bar has been desired.

It is an object of the present invention to provide a cylinder fluid pressure circuit that can move the feed bar up and down even when the press power source is turned off.

[Means for Solving the Problems]

The present invention includes a lift cylinder that urges a cam follower to a lift cam and moves the feed bar in the lift direction, and a brake cylinder that locks the movement of the lift cylinder when discharging fluid and unlocks the movement of this cylinder when supplying fluid. In the fluid pressure circuit for a cylinder of the transfer press, a switching means, an auxiliary means, and an operating means are provided, and the switching means is configured to switch between a fluid supply state and a fluid discharge state from the fluid source to the brake cylinder. The means is configured to allow the fluid supply from the fluid source to the brake cylinder when the switching means is in the state of discharging the fluid from the brake cylinder, and the operating means is configured to cause the auxiliary means to supply the fluid. .

[Action]

In the present invention having such a configuration, if foreign matter is caught between the feed bar and the bolster during the down stroke of the feed bar, the operation of the press is stopped for safety. In this case, when the fluid is discharged from the brake cylinder by the switching means, the movement of the lift cylinder is locked while the foreign matter is caught.

At this time, in order to prevent damage to the feed bar and the like, it is necessary to remove foreign matter. For that purpose, the operating means is operated to cause the auxiliary means to supply the fluid. Then, the fluid sent from the fluid source is supplied to the brake cylinder, whereby the brake cylinder is unlocked and the feed bar can be moved up and down.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1 showing the overall structure of a transfer press, a crown 2 is arranged above a bed 1 via a column, and a lift cam 4 is attached to a crankshaft 3 in the crown 2. This lift cam 4
In the lower left of the figure, a lever 6A having a cam follower 5A that abuts against the lift cam 4 attached to one end is swingably arranged, and a rod 8A is connected to the other end of this lever 6A via an overload safety device 7. Has been done.

The rod 8A is connected to the lift-down interlocking means 9A at the lower side. This interlocking means 9A is connected to the rod 8 via a gear mechanism 91 including a rack and a pinion.
The spline shaft 11 connected to A, the pinion 16 attached to the spline shaft 11 so as to be axially movable and integrally rotatable, and the feed bar 10 that meshes with the pinion 16 and has a holding member 14 on the upper part thereof. The rack 15 is attached, and the feed bar 10 is lifted by lowering the rod 8A, and the feed bar 10 is lowered by raising the rod 8.

Further, a cam follower 5 is provided on the lower right side of the lift cam 4 in the figure.
A lever 6B to which B is attached, an overload safety device 7 and a rod 8B are arranged.
It is connected to the clamp / unclamp interlocking means 9B in the bolster. The interlocking means 9B is connected to the rod 8B via a gear mechanism 92 and has a ball screw shaft 12 formed with both forward and reverse screws, and the forward and reverse rotations of the screw shaft 12 cause the rack 15 to be separated from each other by a screw shaft. Cart 13 for supporting 12 so as not to be movable in the axial direction but to be movable in the vertical direction
And a guide 17 which is fixed to the cart 13 and moves the pinion 16 along the axial direction, and the feed bar 10 is clamped / unclamped by moving the rod 8B up and down.

The specific construction of the overload safety device 7 is shown enlarged in FIG. In FIG. 2, in the safety device 7, a cylinder portion 18 is rotatably attached to a lever 6A, a piston portion 19 is fitted to the cylinder portion 18, and a connecting rod 19A fixed to the lower end of the piston portion 19 is connected to a rod. 8A is connected and fixed to the upper end of the cylinder portion 18, the piston portion 19 is provided with a seal portion 20 which is oil-tightly fitted in the inner portion of the cylinder portion 18, and a large diameter portion 21 larger than the piston portion 19 is provided in the inner portion of the seal portion 20. An oil drain port 22 and a large diameter portion 21 are provided with oil filler ports 23, respectively, and a detector 24 for detecting relative displacement in the vertical direction between the cylinder portion 18 and the piston portion 19 to turn off the press power is provided. When the rod 8 is pulled up with respect to 18 and a predetermined rod pulling down force is exerted, the oil supply port 23 and the oil drainage port 22 are made to communicate with each other so that the cylinder portion 18 and the piston portion 19 are vertically displaced relative to each other. It was and is configured to prevent overloading the rod 8.

In FIG. 1, a lift cylinder 2 is provided at the lower end of the rod 8A.
6 is arranged, and a brake cylinder 27 is provided below the cylinder 26.

The construction of these cylinders 26, 27 is shown enlarged in FIG. In FIG. 3, the lift cylinder 26
2 fixed to the rod 8A inside the case 26A
6B is provided, and this piston 26B has a case 26A.
When air is supplied from the first port 26C at the upper part of the rod, it is pushed down and urges the rod 8A downward, whereby
The cam follower 5A is brought into contact with the lift cam 4, and the feed bar 10 is raised via the interlocking means 9A.
Further, a second port 26D is formed in the lower portion of the case 26A, and when air is supplied from the second port 26D,
The piston 26B is pushed up together with the rod 8A.

The brake cylinder 27 includes a main body 30 fixed to the case 26A, and a rod portion 31 connected to the rod 8A is inserted into the inside 30A of the main body 30. A plurality of steel balls 33 are arranged in the interior 30A, and a brake shoe 32 is interposed between the steel balls 33 and the rod portion 31. An inner peripheral taper portion 34B is capable of contacting the steel ball 33 with a lower surface pressure receiving portion 34A formed on the brake piston 34 in the main body 30. A pressing spring 35 is interposed between the upper surface 34C of the brake piston 34 and the main body 30, and when the piston 34 is biased downward by the spring force of the spring 35, the taper portion 34B causes the steel ball 33 to move the rod shaft. The rod portion 31 is locked by pressing it in the core direction and via the brake shoe 32. A port 36 for air supply / exhaust is formed in the main body 30, and the pressure receiving portion 34A of the piston 34 is formed from the port 36.
When air is supplied to the side, the piston 34 is raised against the spring force of the pressing spring 35 and the rod portion 31 is unlocked.

The lift cylinder 26 and the brake cylinder 27 are
It is connected to a cylinder fluid pressure circuit 40 shown in FIG. 4, and this cylinder fluid pressure circuit 40 is composed of a lift fluid pressure circuit 41 and a brake fluid pressure circuit 42. A lift cylinder 25 having the same structure as the lift cylinder 26 is arranged at the lower end of the rod 8B, and the lift cylinder 25 is connected to a circuit (not shown) having the same structure as the lift fluid pressure circuit 41. ing.

The lift fluid pressure circuit 41 has the following configuration.
A mother pipe 46 having an opening / closing valve 44 in the middle is connected to a fluid source 43 composed of an air source, and a branch pipe 46A branched from the mother pipe 46 is provided with a pressure reducing valve 45 in the middle and also downstream thereof. It is branched into two branch pipes 46C and 46D on the side. The branch pipes 46C and 46D are respectively connected to the first port 26C of the lift cylinder 26, and a tank 47 and an electromagnetic switching valve 48 are arranged in the middle thereof. These switching valves 48 are provided for the branch pipes 46C,
Allows the air in 46D to flow, and the branch pipe 4 when not energized
The circulation of the air in 6C and 46D is cut off so that the air in the lift cylinder 26 can be discharged through the silencer 49. When air flows through the branch pipes 46C and 46D by the electromagnetic switching valve 48, the rod 8A is raised. Also,
Branch pipes 46C, 46D on the cylinder side of the electromagnetic switching valve 48
A communication pipe 50 is connected between them, and a pressure switch 51 is arranged in the communication pipe 50. The pressure switch 51 detects the contact of the cam follower 5 with the lift cam 4 by detecting that the air in the cylinder 26 has a predetermined pressure value.

Exhaust pipes 53A and 53B are connected to the second port 26D of the lift cylinder 26 via a quick exhaust valve 52, respectively. The discharge pipes 53A and 53B are joined to one discharge pipe 53 and connected to the branch pipe 46C. A safety device return valve 54 is disposed in the discharge pipe 53, and the return valve 54 allows the air in the discharge pipe 53 to flow when energized and shuts off the flow of air in the discharge pipe 53 when deenergized. Then, the air in the cylinder 26 can be discharged through the silencer 49. With this return valve 54, the discharge pipe 5
When air is circulated in the rod 3, the rod 8A is lowered.
Here, the fluid source 43, the safety device return valve 54 and the lift cylinder 26 constitute a safety device return means 55.

The brake fluid pressure circuit 42 has the following configuration. A branch pipe 46B is branched from the mother pipe 46, and the branch pipe 46B includes a pressure reducing valve 59 and the quick exhaust valve 5
It is connected to the port 36 of the brake cylinder 27 via 6. An electromagnetic switching valve 58 as switching means is arranged at the intermediate portion 46E of the branch pipe 46B.
Is from the fluid source 43 to the brake cylinder 3 when energized.
4 is switched between the state of supplying fluid to No. 4 and the state of discharging fluid when not energized.

Branch pipe intermediate portion 26B on the left side of the electromagnetic switching valve 58 in the drawing
The bypass pipeline 60 is branched from the bypass pipeline 6
0 is connected to the three-way two-position switching valve 61 arranged in the intermediate portion 26E on the right side of the electromagnetic switching valve 58 in the figure. The switching valve 61 switches between a state in which the air flows from the fluid source 43 to the brake cylinder 27 and a state in which the air flows in the intermediate portion 46E and the bypass pipe line 60. Here, an auxiliary means 62 is composed of the bypass conduit 60 and the three-way two-position switching valve 61, and the auxiliary means 62 is operated by the operating means 63.

The operating means 63 includes a pilot pipe 64 for sending operating air to the three-way two-position switching valve 61, and a manual operating valve 65 for blocking or allowing the flow of air in the pilot pipe 64. I have it. When the operation valve 65 allows the air to flow in the pilot pipe 64, the switching valve 61 is operated to send the air from the intermediate portion 46E to the brake cylinder 27, while the air in the pipe 64 is not supplied. When the flow of air is blocked, the switching valve 61 is operated to send air from the bypass line 60. Further, a pressure switch 66 is arranged in the pilot conduit 64, and this pressure switch 66 detects the state in which air is being sent to the conduit 64, so that the air flows through the bypass conduit 60. It is to detect that it is not sent to the cylinder 27.

Next, the operation of this embodiment will be described.

When the lift cam 4 is rotated by the crankshaft 3 in the normal operation state of the press, the cam followers 5A, 5
The feed bar 10 is lifted down, clamped and unclamped via B, the levers 6A and 6B, the rods 8A and 8B, and the interlocking means 9A and 9B, and the blank is conveyed. At this time, since the cam follower 5A is in contact with the lift cam 4, air is supplied to the cylinder 26. That is,
In this state, the electromagnetic switching valve 4 of the lift fluid pressure circuit 41
8 is energized, and air flows from the fluid source 43 to the pressure reducing valve 4
5, it passes through the tank 47 and the electromagnetic switching valve 48, and is sent from the first port 26C into the lift cylinder 26. When the piston 26C in the cylinder 26 is lowered, the pressure generated below the piston 26C is released through the quick exhaust valve 52.

In the normal operation state, the brake fluid pressure circuit 42
Means that the electromagnetic switching valve 58 is energized and the operation valve 6
Since 5 is in a state of permitting the air flow in the pilot pipe 64, the three-way two-position switching valve 61 allows the air flow from the branch pipe intermediate portion 46E to the brake cylinder 27. As a result, in this cylinder 27, the brake piston 34 is pushed up against the spring force of the pressing spring 35, the pressing of the steel ball 33 by this piston 34 is released, and the lock of the rod 8A is released. Therefore, by driving the crankshaft 3, a lift-down operation according to the shape of the lift cam 4 can be obtained.

Here, during the down stroke of the feed bar 10, foreign matter is caught between the feed bar 10 and the bolster and the rod 8
A, the interlocking means 9A, etc. may be overloaded. Due to this overload, the piston portion 19 tries to stop at that position regardless of the rise of the cylinder portion 18 of the overload safety device 7, so that a so-called relative pulling force acts on the piston portion 19. When the pulling down force becomes a predetermined value or more, the piston portion 19 and the cylinder portion 18 are displaced relative to each other, the piston portion 19 is disengaged from the seal portion 20, and the oil supply port 23 and the oil drainage port 22 are communicated with each other to prevent excessive passage to the rod 8. The load is prevented, and the relative displacement is detected by the detector 24, the press power is turned off, and the operation of the press is stopped.

Then, the electromagnetic switching valve 48 of the lift fluid pressure circuit 41 is brought into a non-energized state, switches to the state shown in FIG. 4, and air is discharged from the lift cylinder 26. Then, the contact between the lift cam 4 and the cam follower 5A is released, and as a result, the rod 8A becomes free and the feed bar 10 tries to lower due to its own weight, but the electromagnetic switching valve 58 of the brake fluid pressure circuit 42 is also de-energized. Since the state is switched to the state shown in the figure, air is discharged from the brake cylinder 27 through the rapid exhaust valve 56 and the like. Then, the brake piston 34 is pushed down by the spring force of the pressing spring 35, the taper portion 34 B of the piston 34 presses the steel ball 33, and the rod 8 is unlocked via the brake shoe 32.

After that, in order to prevent damage to the feed bar 10 and the like, the operation valve 65 is manually switched to a state in which the air flow in the pilot conduit 64 is blocked as shown in FIG. Then, the three-way two-position switching valve 61 is switched to the illustrated state, and the air from the fluid source 43 is sent into the brake cylinder 27 through the pressure reducing valve 59, the bypass pipe 60, the switching valve 61 and the quick exhaust valve 56. . Then, in the cylinder 27, the piston 34 is pushed up, the pressing of the steel ball 33 by the piston 34 is released, and the lock of the rod 8 is released.

Thereafter, in order to return the overload safety device 7, the safety device return valve 54 of the safety device return means 55 is energized. Then,
The valve 54 is switched, and the air flows through the exhaust pipe 53 and is sent into the lift cylinder 26. As a result, the rod 8 is raised and the piston portion 19 of the safety device 7 is forcibly pushed up to return to the original position. If oil is supplied into the cylinder portion 18 in this state, it works as a safety device.

According to the present embodiment as described above, the cylinder fluid pressure circuit 4
0, electromagnetic switching valve 58 as switching means, auxiliary means 62
Since the brake fluid pressure circuit 42 including the operating means 63 is provided, even if the press power source is cut off and the switching valve 58 is switched and the rod 8A is locked by the brake cylinder 27, the rod 8A can be moved up and down. .
Therefore, even if the rod 8A is locked while the foreign matter is sandwiched between the feed bar 10 and the bolster, the foreign matter can be easily removed. Further, since the lifting fluid pressure circuit 41 is provided with the safety device restoring means 55 including the safety device restoring valve 54 and the like, the overload safety device 7 can be easily restored. Further, in this embodiment, the brake cylinder 2
Since the quick exhaust valve 56 is connected to 7, the cylinder 27
Can be operated quickly. Furthermore, since the brake cylinder 27 is released by pneumatic pressure, the brake can be quickly operated from this point as well.
In addition, the pilot line 6 in the brake fluid pressure circuit 42
Since the pressure switch 66 is arranged at 4, the electromagnetic switching valve 58
Thus, when the air in the brake cylinder 27 is exhausted and the brake is applied, it is possible to prevent the air from being sent from the bypass conduit 60 to the cylinder 27 so that the brake cannot be applied. Further, in the lift fluid pressure circuit 41, a pressure switch 5 for detecting the pressure of air in the lift cylinder 26.
Since the cam follower 5A is provided with 1, it can be detected that the predetermined biasing force is brought into contact with the lift cam 4 by the cam follower 5A.

In the present invention, the brake fluid pressure circuit 42 may be configured as shown in FIG. That is, in FIG. 5, in the central portion 46E of the branch pipe 46B, there are a state in which communication of air from the fluid source 43 to the brake cylinder 27 is allowed and a state in which the communication is blocked and air is discharged from the cylinder 27. A four-way two-position switching valve 70 for switching between is arranged. The switching valve 70 is connected to a pilot pipe 71, and the pilot pipe 71 is connected to a pipe 72 and a bypass pipe 73 branched from the mother pipe 46, respectively.
A shuttle valve 74 is arranged at a connection point between the pipe 72 and the pipe lines 71 and 73. This shuttle valve 74
Selects whether the air to be sent to the pilot pipe 71 is passed through the pipe 72 or the bypass pipe 73. An electromagnetic on-off valve 75 is arranged in the pipe 72, and the on-off valve 75 switches the pipe 72 between open when energized and closed when not energized. Here, the four-way two-position switching valve 70 and the electromagnetic on-off valve 75 constitute a switching means 76, and the switching means 76 causes the four-way two-position switching valve 70 to be operated by opening the electromagnetic on-off valve 75 when energized. The air is supplied to the switching valve 70 and the switching valve 70 is evacuated from the cylinder 27 when the solenoid valve 75 is closed. Further, the pilot line 71, the shuttle valve 74 and the bypass line 7
The auxiliary means 77 is composed of 3 and the auxiliary means 77 is
When the switching means 76 discharges air from the cylinder 27, the air from the fluid source 43 is sent to the switching valve 70 so that the air can be supplied to the brake cylinder 27. Further, a manual on-off valve 78 as an operating means is arranged in the bypass line 73, and this on-off valve 78 causes the auxiliary means 77 to supply the above-mentioned air by an opening operation.

In the brake fluid pressure circuit 42, the electromagnetic opening / closing valve 75 is energized and the opening / closing valve 78 is opened in the normal operating state of the press. Then, the air from the fluid source 43 passes through the valve 75 and the shuttle valve 74, and then the four-way two-position switching valve 70.
Is sent to the brake cylinder 27 through the branch valve 46B. As a result, the lock of the rod 8A by the cylinder 27 is released. Further, when the press power is turned off, the solenoid opening / closing valve 7
5 is de-energized and opened to prevent the supply of air to the switching valve 70, the switching valve 70 discharges the air in the cylinder 27, and the cylinder 27 locks the rod 8A. At this time, to release this locked state,
The on-off valve 78 is switched to the closed state. Then, the air is sent to the four-way two-position switching valve 70 through the opening / closing valve 78 and the shuttle valve 74, and the switching valve 70 causes the air to flow into the branch pipe 46.
It circulates in B and is sent to the cylinder 27.

According to such a brake fluid pressure circuit 42, the same effect as that of the above-described embodiment can be obtained.

Further, the brake cylinder of the present invention may be configured as shown in FIG. The brake cylinder 80 has the rod portion 3
1 is provided with a metal sleeve 81 whose upper portion is fixed to the lift cylinder 26, and a contact portion 82 for locking the rod portion is formed on the inner circumference of the sleeve 81. The oil is supplied to and discharged from the rod portion 31. Note that, in FIG. 6, the degree of enlargement of the sleeve 81 is extremely illustrated in order to facilitate understanding of the contents.

[Effect of device]

According to the present invention as described above, even if the press power is cut off,
The effect is that the feed bar can be easily moved up and down.

[Brief description of drawings]

1 is a schematic configuration diagram of an embodiment according to the present invention, FIG. 2 is an enlarged sectional view of an overload safety device, FIG. 3 is an enlarged sectional view of a lift cylinder and a brake cylinder, and FIG. 4 is a fluid for a cylinder. FIG. 5 is a configuration diagram of a pressure circuit, FIG. 5 is a configuration diagram showing a modified example of a cylinder fluid pressure circuit, and FIG. 6 is a sectional view showing a modified example of a brake cylinder. 4 ... Lift cam, 5A, 5B ... Cam follower, 8A, 8
B ... Rod, 10 ... Feed bar, 26 ... Lift cylinder, 40 ... Cylinder fluid pressure circuit, 43 ... Fluid source, 5
8, 76 ... Switching means, 62, 77 ... Auxiliary means, 63, 7
8 ... Operation means.

Claims (1)

[Scope of utility model registration request] 1. A lift cylinder for urging a cam follower to a lift cam and moving a feed bar in a lift direction, and a brake cylinder for locking movement of the lift cylinder during fluid discharge and unlocking movement of the lift cylinder during fluid supply. In a fluid pressure circuit for a cylinder of a transfer press having a switching means, switching means is provided for switching between a fluid supply state from the fluid source to the brake cylinder and a fluid discharge state, and when the fluid is discharged from the brake cylinder by the switching means, A fluid pressure circuit for a cylinder, characterized in that auxiliary means for supplying fluid to the brake cylinder is provided, and operation means for supplying fluid to the auxiliary means is provided.