JPH05223104A - Deceleration control method for pneumatic cylinder - Google Patents

Abstract

PURPOSE:To obtain a deceleration control method for a pneumatic cylinder capable of performing translation from a deceleration stroke to a low speed stroke smoothly. CONSTITUTION:A pneumatic cylinder for this deceleration control method performs a high speed stroke in which a load (W) is moved at a specified high speed by supplying compressed air from an air pressure source 50 to an operating chamber 6, a deceleration stroke in which the operating chamber 6 is decompressed in response to the kinetic energy of the load (W) responding to that high speed after the high speed stroke, a supplementary stroke in which the compressed is supplied air from the air pressure source 50 to the operating chamber 6 in response to the cubic volume of the operating chamber 6 after the deceleration stroke, and a low speed stroke in which the compressed air responding to the low speed of a load is supplied the operating chamber 6 after the supplementary stroke. Therefore, prompt deceleration can be carried out in the deceleration stroke by allowing the pressure inside the operating chamber 6 to recover in response to its cubic volume once in the supplementary stroke after the deceleration stroke, and also smooth translation from a deceleration state to low speed can be carried out, in the following low speed stroke.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deceleration control method for a pneumatic cylinder that reduces the speed of a load driven by the pneumatic cylinder from high speed to low speed.

[0002]

2. Description of the Related Art Conventionally, as a method for reducing the speed of a load driven by a pneumatic cylinder from high speed to low speed,
The method disclosed in Japanese Patent Application No. 2-100878 is known. In this method, for example, when the load is moved horizontally by the pneumatic cylinder, in the high speed stroke, compressed air is supplied to the working chamber to move the load at high speed. Then, at the time of shifting from the high speed to the low speed, before that, the pressure of the working chamber is reduced according to the kinetic energy of the load, the speed of the load is reduced, and thereafter, compressed air according to the low speed is supplied to the working chamber. It was designed to carry out a low speed supply.

[0003]

However, in such a conventional method, when shifting from the deceleration stroke to the low speed stroke, for example, when the stroke of the pneumatic cylinder is long, or when the cylinder diameter is large, When the volume of the pneumatic cylinder is large, it takes time to reduce the pressure of the working chamber in the deceleration stroke and then increase the pressure of the working chamber to the pressure corresponding to the low speed in the low speed stroke, and the load is temporarily stopped. There was a problem that it would end up.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a deceleration control method for a pneumatic cylinder which can smoothly shift from a deceleration stroke to a low speed stroke.

[0005]

In order to achieve the above object, the present invention takes the following methods to solve the problems. That is, in a deceleration control method of a pneumatic cylinder, in which air is supplied to and discharged from a working chamber of a pneumatic cylinder connected to a load, and the moving speed of the load is decelerated from a predetermined high speed to a predetermined low speed. A high-speed stroke in which air is supplied to the working chamber to move a load at a predetermined high speed, a deceleration stroke in which the working chamber is decompressed according to the kinetic energy of the load according to the high speed after the high-speed stroke, and the deceleration After the stroke, an auxiliary stroke that supplies compressed air from the air pressure source to the working chamber according to the volume of the working chamber, and a low speed stroke that supplies compressed air according to the low speed of the load to the working chamber after the auxiliary stroke. This is a deceleration control method for a pneumatic cylinder, which is characterized in that

[0006]

In the deceleration control method for the pneumatic cylinder, the compressed air from the pneumatic pressure source is supplied to the working chamber in the high speed stroke,
Move the load at high speed. Then, when shifting from the high speed to the low speed, first, in the deceleration stroke, the working chamber is decompressed according to the kinetic energy of the load corresponding to the high speed. Therefore, the load is quickly decelerated according to the high speed. After this deceleration stroke, in the auxiliary stroke, compressed air is supplied according to the volume of the working chamber to recover the pressure in the working chamber. Subsequently, in the low speed stroke, compressed air corresponding to the low speed is supplied to the working chamber.
Therefore, the load smoothly shifts to a low speed.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is an operation explanatory diagram of a high speed stroke of a deceleration control method for a pneumatic cylinder according to an embodiment of the present invention. 1 is a pneumatic cylinder, 2 is a piston, 3 is a piston rod, 4 is a head side port, 5 is a rod side port,
6 is a head side working chamber, 7 is a rod side working chamber, 8 is a switching valve, and W is a load applied to the piston rod 3. In this embodiment, the rod side port 5 is open to the atmosphere as it is, compressed air is supplied to and discharged from the head side working chamber 6, and the load W is moved upward against gravity.

The inside of the housing 9 of the switching valve 8 is divided into three chambers by a first partition wall 10 and a second partition wall 12, in this embodiment, a pressure control chamber 14, an atmospheric pressure chamber 16 and a primary pressure chamber 18. Has been. A pressure adjusting piston 20 is slidably arranged in the pressure adjusting chamber 14, and the pressure adjusting chamber 14 includes the pressure receiving chamber 22 between the pressure adjusting piston 20 and the first partition wall 10, the pressure adjusting piston 20, and the housing 9. And a back pressure chamber 24 between the upper wall and the upper wall.

The back pressure chamber 24 is opened to the atmosphere by an exhaust port 26, and the pressure receiving chamber 22 is connected to a pressure receiving chamber port 28. A pressure adjusting spring 30 is arranged in the back pressure chamber 24 to urge the pressure adjusting piston 20 toward the pressure receiving chamber 22.
The urging force of the pressure adjusting spring 30 can be adjusted by rotating the handle screw 32 and changing the deflection amount of the pressure adjusting spring 30 via the spring receiver 34.

The atmospheric pressure chamber 16 between the first partition wall 10 and the second partition wall 12 and the primary pressure chamber 18 between the second partition wall 12 and the lower wall of the housing 9 are formed in the second partition wall 12. Communication hole 3
It is connected by 6. Communication hole 36 on the primary pressure chamber 18 side
A first valve seat 40 is formed around the, and a second valve seat 42 is formed around the communication hole 36 on the atmospheric pressure chamber 16 side.

A first valve element 44 is movably arranged in the primary pressure chamber 18, and is urged by a spring 46 to be seated on the first valve seat 40. This primary pressure chamber 18 has an air pressure source 50 via an input port 48.
Is in communication with. A second valve body 52 is movably arranged in the atmospheric pressure chamber 16 and is urged by a spring 54 to be seated on the second valve seat 42.
The atmospheric pressure chamber 16 is open to the atmosphere via the exhaust port 56.

Further, a stem 57 extends integrally from the pressure adjusting piston 20 through the first partition wall 10, and the stem 57 further penetrates the second valve body 52 slidably. However, it extends to between the first valve body 44 and the second valve body 52. Then, between the first valve body 44 and the second valve body 52, the diameter is increased to form a large diameter portion 57a, and the pressure adjusting piston 20 is in contact with the first partition wall 10. Thus, the large diameter portion 57a pushes down the first valve body 44 and separates it from the first valve seat 40.

On the other hand, a supply / discharge port 58 is formed so as to communicate with the communication hole 36, and the supply / discharge port 58 is connected to the head side port 4 via a sluice valve 60 which can be connected / disconnected by switching the excitation of a solenoid. It is connected to the. This gate valve 60
A flow rate adjusting valve 62 whose flow rate can be adjusted is connected in parallel with.

A pressure adjusting port 64 is formed so as to communicate with the communication hole 36.
It is connected to the pressure receiving chamber port 28 via a position electromagnetic switching valve 66 (hereinafter referred to as electromagnetic valve 66). Solenoid valve 66
Energizes the solenoid to adjust the pressure adjustment port 64
And a second position 66b that connects the pressure receiving chamber port 28 and the pressure adjusting port 64 to each other.

Next, each step of the deceleration control method of the pneumatic cylinder realized by the above-mentioned structure will be described. First, as shown in FIG. 1, in the high speed stroke, the gate valve 6
0 switches to a state in which the supply / discharge port 58 and the head-side port 4 communicate with each other, and the solenoid valve 66 switches to the first position 66a. As a result, the pressure receiving chamber port 28 is opened to the atmosphere and the pressure adjusting port 64 is shut off. Therefore, the pressure adjusting piston 20 is pressed against the first partition wall 10 by the pressure adjusting spring 30, and the large diameter portion 57a of the stem 57 moves the first valve body 44 to the first position.
It is separated from the valve seat 40. Further, the second valve body 52 is seated on the second valve seat 42 by the spring 54.

As a result, the compressed air from the air pressure source 50 passes through the input port 48, the primary pressure chamber 18, the communication hole 36, the supply / discharge port 58, the gate valve 60, and the head side port 4,
It is supplied to the head side working chamber 6. Therefore, piston 2
Receives this acting force and moves the load W upward at high speed.

After the completion of the high speed stroke, in the deceleration stroke in which the high speed of the load W is decelerated, as shown in FIG. 2, the solenoid valve 66 is switched to the second position 66b to connect the pressure receiving chamber port 28 and the pressure adjusting port 64 to each other. However, the gate valve 60 remains in a state where the supply / discharge port 58 and the head-side port 4 communicate with each other. Therefore, the head side working chamber 6 includes the gate valve 60, the supply / discharge port 58, the communication hole 36, the pressure adjusting port 64, the solenoid valve 66, and the pressure receiving chamber port 28.
Through the pressure receiving chamber 22.

The pressure adjusting piston 20 moves due to the balance between the pressure in the pressure receiving chamber 22 acting on the pressure adjusting piston 20 and the urging force of the pressure adjusting spring 30. This pressure chamber 2
When the pressure in the head-side working chamber 6 communicating with 2 is high, the large-diameter portion 57a lifts the second valve body 52 and separates it from the second valve seat 42 by the movement of the pressure adjusting piston 20.
Therefore, the communication hole 36 is opened to the atmosphere through the atmospheric pressure chamber 16 and the exhaust port 56, the compressed air in the head side action chamber 6 is released to the atmosphere, and the pressure is reduced.

When the pressure decreases, the large diameter portion 57a moves to the first valve body 44 side, and when it balances with the urging force of the pressure adjusting spring 30, the second valve body 52 is seated on the second valve seat 42. In this way, the pressure in the head-side working chamber 6 is adjusted according to the biasing force of the pressure-adjusting spring 30, and the compressed air in the head-side working chamber 6 is exhausted to this pressure. Then, accordingly, the moving speed of the load W is rapidly reduced.

The biasing force of the pressure adjusting spring 30 is generated by the handle 3
Since it can be adjusted by rotation of 2, the predetermined biasing force is adjusted in advance according to the kinetic energy corresponding to the speed of the load W and the weight. Further, the de-excitation time of the solenoid valve 66 is adjusted according to the magnitude of kinetic energy to adjust the degree of deceleration.

After the deceleration stroke, in the auxiliary stroke, the solenoid valve 66 is switched to the first position 66a, the pressure receiving chamber port 28 is opened to the atmosphere, and the pressure adjusting port 64 is shut off, as shown in FIG. To be done. Then, the gate valve 60 is maintained in the communication state. As a result, the pressure adjusting piston 20 is pushed down by the urging force of the pressure adjusting spring 30, and the large diameter portion 57
a separates the first valve body 44 from the first valve seat 40. Therefore, the compressed air from the air pressure source 50 is transferred to the input port 48,
Primary pressure chamber 18, communication hole 36, supply / discharge port 58, gate valve 6
0, and is supplied to the head side working chamber 6 via the head side port 4.

As a result, the pressure in the head side working chamber 6, which has greatly decreased during the deceleration stroke, is rapidly recovered. The extent of this recovery depends on the volume inside the head-side working chamber 6. For example, when the stroke of the pneumatic cylinder 1 is long, the volume is large, and when the cylinder diameter is large, the volume is large. The larger the volume, the longer it takes for the pressure to recover. Therefore, the solenoid of the sluice valve 60 is excited to adjust the time in which the solenoid valve 60 is in the communicating state according to the size of the volume. Further, the pressure corresponding to the low speed of the load W in the next low speed stroke is also taken into consideration for the adjustment.

In the low speed stroke after the auxiliary stroke, the solenoid valve 66 is maintained at the first position 66a as shown in FIG.
The sluice valve 60 is switched to a shutoff state. Therefore, the compressed air from the air pressure source 50 is supplied to the input port 48, the primary pressure chamber 18, the communication hole 36, the supply / discharge port 58, and the flow rate control valve 6.
2. It is supplied to the head side working chamber 6 via the head side port 4.

The head side working chamber 6 is supplied with compressed air at a flow rate according to the opening degree of the flow rate control valve 62. The opening degree of the flow rate adjusting valve 62 is adjusted in advance according to the extent to which the load W is moved at a low speed. As a result, the load W moves at a low speed. In this way, after the deceleration stroke, once in the auxiliary stroke,
By recovering the pressure in the head-side working chamber 6 according to its volume, it is possible to speedily reduce the speed in the deceleration stroke, and in the next low speed stroke, the deceleration state smoothly shifts to the low speed. When shifting from the stroke to the low-speed stroke, the load W is not temporarily stopped.

In the deceleration stroke, instead of the case of FIG. 4, as shown in the second embodiment of FIG.
Is closed by a plug or the like, and the solenoid valve 70, the pressure receiving chamber port 28
The compressed air may be supplied to the pressure receiving chamber 22 from the air pressure source 50 via the. The same members as those in the above-described embodiment are designated by the same reference numerals and detailed description thereof will be omitted. The same applies below.

As a result, the pressure adjusting piston 20 is lifted, the second valve body 52 is separated from the second valve seat 42, and the compressed air in the head side working chamber 6 is rapidly exhausted from the exhaust port 56. .. At this time as well, the electromagnetic valve 70 is excited to adjust the time of rapid exhaust according to the kinetic energy of the load W, whereby the speed can be rapidly reduced.

Further, instead of the switching valve 8 described above, a switching valve 74 having a second pressure adjusting piston 72 may be used as shown in the third embodiment of FIG. This switching valve 74 supplies the compressed air from the air pressure source 50 to the switching valve 74 by the electromagnetic switching valve 76 to slide the second pressure adjusting piston 72,
The biasing force of the pressure regulating spring 30 may be automatically changed in two steps. As a result, the pressure in the head-side working chamber 6 can be adjusted to be higher, and the load W can be maintained in the stopped state at the rising end.

Further, instead of the switching valve 8, as shown in the fourth embodiment of FIG. 7, air pressure may be used instead of the pressure adjusting spring 30 to apply the urging force of the pressure adjusting piston 20. .. The switching valve 80 is configured such that the back pressure chamber 24 is connected to the air pressure source 50 via a pressure reducing valve 82, and the pressure inside the back pressure chamber 24 is maintained at a predetermined constant pressure by the pressure reducing valve 82. The pressure regulating piston 20 is biased with a constant biasing force.

In the above-described embodiment, the case where the load W is moved upward against the gravity is taken as an example, but the case where the load W is moved horizontally will be described with reference to FIG. In FIG. 8, instead of the switching valve 8, the use of the handle screw 32 is omitted, and a switching valve 90 using a biasing spring 30 that is pre-set with a predetermined biasing force is provided. The supply / discharge port 58 of the first switching valve 90 is connected to the head side port 4, and the supply / discharge port 58 of the second switching valve 92 is connected to the rod side port 5.

In the high speed stroke, the first switching valve 90 switches the solenoid valve 70 to open the pressure receiving chamber 22 to the atmosphere,
The valve body 44 is pushed down to supply the compressed air from the air pressure source 50 to the head side working chamber 6. The second switching valve is
The solenoid valves 94 and 96 are switched to supply compressed air from the air pressure source 50 to the pressure receiving chamber 22, lift the second valve body 52, and open the rod side working chamber 7 to the atmosphere. As a result, the load W moves forward at high speed.

In the next deceleration stroke, the first switching valve 90
By switching the solenoid valve 70, compressed air is supplied from the air pressure source 50 to the pressure receiving chamber 22, the second valve body 52 is lifted, and the compressed air in the head side working chamber 6 is rapidly opened to the atmosphere. Further, the second switching valve 92 switches between the electromagnetic valves 94 and 96 to open the pressure receiving chamber 22 to the atmosphere, push down the first valve body 44, and rapidly supply the compressed air to the rod side working chamber 7. ..
This deceleration process is executed for a time period corresponding to the kinetic energy of the load W. As a result, the movement of the load W is rapidly decelerated.

Subsequently, in the auxiliary stroke, the first switching valve 90
Switches the solenoid valve 70 to open the pressure receiving chamber 22 to the atmosphere, depresses the first valve body 44, and supplies compressed air from the air pressure source 50 to the head side working chamber 6. Further, the second switching valve 92 switches the solenoid valve 94 to communicate the pressure receiving chamber 22 and the communication hole 36, and adjusts the pressure of the rod side action chamber 7 to a pressure according to the urging force of the pressure adjusting spring 30. Press. This allows
The pressure in the head side working chamber 6 recovers rapidly. This auxiliary process is executed for a time period corresponding to the volume of the head side working chamber 6.

Next, in the low speed stroke, the first switching valve 90
Switches only the sluice valve 60 and supplies compressed air to the head side working chamber 6 via the flow rate control valve 62. At this time, the flow rate of the flow rate control valve 62 is adjusted so that the pressure in the head side working chamber 6 becomes higher than the pressure in the regulated rod side working chamber 7 by an amount corresponding to the low speed of the load W. To be done.
As a result, the load W is quickly decelerated from the high speed, and smoothly shifts to the low speed forward movement.

The present invention is not limited to the embodiments as described above, and can be carried out in various modes without departing from the scope of the present invention.

[0035]

As described above in detail, according to the deceleration control method for a pneumatic cylinder of the present invention, after the deceleration stroke, the pressure in the working chamber is restored in accordance with the volume in the auxiliary stroke, so that the deceleration stroke can be reduced. In addition to being able to quickly decelerate, in the next low speed stroke, when the speed is gradually reduced from the deceleration state to the low speed stroke,
The load W is never stopped.

[Brief description of drawings]

FIG. 1 is an operation explanatory diagram of a high speed stroke of a deceleration control method for a pneumatic cylinder as an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of a deceleration stroke of the present embodiment.

FIG. 3 is an operation explanatory diagram of an auxiliary stroke of the present embodiment.

FIG. 4 is an operation explanatory diagram of a low speed stroke of the present embodiment.

FIG. 5 is an operation explanatory diagram of a deceleration stroke as a second embodiment.

FIG. 6 is an operation explanatory view as a third embodiment.

FIG. 7 is an operation explanatory view as a fourth embodiment.

FIG. 8 is an operation explanatory diagram of an auxiliary stroke of the embodiment when a load is moved horizontally.

[Explanation of symbols]

W ... Load 1 ... Pneumatic cylinder 6
... Head-side working chamber 7 ... Rod-side working chamber 8, 74, 80, 90, 92
... Switching valve 20 ... Pressure adjusting piston 22 ... Pressure receiving chamber 4
4 ... 1st valve body 50 ... Air pressure source 52 ... 2nd valve body 6
0 ... Gate valve 62 ... Flow control valve 66 ... Solenoid valve

Claims (1)

[Claims] 1. A deceleration control method for a pneumatic cylinder, wherein air is supplied to and discharged from a working chamber of a pneumatic cylinder connected to a load, and the moving speed of the load is decelerated from a predetermined high speed to a predetermined low speed. A high-speed stroke for supplying compressed air from the chamber to the working chamber to move the load at a predetermined high speed, and a deceleration stroke for decompressing the working chamber according to the kinetic energy of the load according to the high speed after the high-speed stroke. An auxiliary step of supplying compressed air from the air pressure source to the working chamber according to the volume of the working chamber after the deceleration step, and a compressed air according to the low speed of the load to the working chamber after the auxiliary step A method for controlling deceleration of a pneumatic cylinder, characterized by performing a low speed stroke.