JPH112203A - Air cylinder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air cylinder of simple structure, being high in universality, and capable of stopping in an intermediate position. SOLUTION: A pressure is respectively fed to air chamber 5 and 6 on both sides of a piston 3 slid in an air cylinder 2, a force exerted on the front and the rear of the piston 3 is uniformized, and a piston rod 4 is stopped in an arbitrary intermediate position by a pressure control. Since an air cylinder device is formed in a manner described above, a lock mechanism is not arranged for a stop of the piston 3, whereby structure is simple and a cost is low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air cylinder device having a piston which slides in an air cylinder, and a cylinder rod having a base fixed to one side of the piston and projecting outside the cylinder.

[0002]

2. Description of the Related Art A general air cylinder normally supplies high-pressure air to one of a first air chamber on the piston rod side and a second air chamber on the opposite side, and the piston comes into contact with the inner wall of the cylinder. To a desired linear motion by selectively converting the rod between the extended position and the retracted position.

[0003]

In the conventional structure having the above-mentioned simple structure, since the rod is allowed to move only at two positions, the operation form is simple and the control mechanism is complicated. However, there is a problem that it is not possible to sufficiently cope with the problem.

[0004] In order to solve this problem, there is a configuration in which a lock mechanism is operated to forcibly stop the piston at an intermediate position, as a method that enables the rod to be stopped at an intermediate position. By the way, in this configuration, in order to enhance the positioning accuracy at a predetermined intermediate position, the piston is suddenly locked and stopped against the pressure by a mechanical means, and there is a problem that the structure becomes complicated and expensive. Was. On the other hand, a linear movement type actuator that can be stopped at an appropriate position without using an air cylinder is a servomotor. Although there is a mechanism that links a motor such as a stepping motor and a motor with a brake with a linear motion mechanism, such a means has a problem that the structure is further complicated and the size is increased.

An object of the present invention is to provide an air cylinder device having a simple structure and high versatility.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an air cylinder device having a piston sliding in an air cylinder, and a cylinder rod having a base fixed to one side of the piston and projecting out of the cylinder. A first air chamber on the piston rod side located before and after the piston, and an air control mechanism for performing pressure control of the second air chamber on the opposite side, and the air control mechanism controls the pressure only in one of the air chambers. And a stop mode in which the piston is stopped at an intermediate position by supplying pressure to both air chambers to equalize the forces applied to the front and rear of the piston, and selectively performing the stop mode. Air cylinder device.

In such a configuration, the operation mode is selected and executed by the air control mechanism, pressure is supplied to only one of the air chambers, and after the piston is moved to a predetermined position, the piston reaches the intermediate position, or Immediately before that, the stop mode is executed and high-pressure air is supplied to the other low-pressure side air chamber. This allows
The force applied before and after the piston becomes equal, and the piston stops. Thus, the piston and the piston rod can be stopped at a required intermediate position.

If the same pressure is applied to both air chambers to equalize the forces applied to the front and rear of the piston, the pressure receiving area differs between the surface with the rod and the surface without the rod,
The force on the second air chamber side is increased, and the piston cannot be stopped properly. Therefore, the first air chamber and the second air chamber are connected to the same air source, and a pressure adjusting device is inserted into the air supply path, and the first air chamber is set at the intermediate stop position by the pressure adjustment by the pressure adjusting device. Is proposed to make the pressure applied slightly before and after the piston slightly higher than the pressure of the second air chamber.

The stop control at this intermediate position is performed by means such as providing a sensor outside the cylinder, detecting a permanent magnet or the like provided on the piston with the sensor, and converting the solenoid valve of the air control device based on the detection signal. Can be performed. By doing so, the piston can be stopped at an arbitrary position by appropriately moving the sensor along the cylinder, and adjustment is facilitated.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. The air cylinder device 1 has a basic configuration that is widely used, and has a piston 3 that slides in the front-rear direction inside the air cylinder 2, a base end fixed to one side of the piston 3, and protrudes outside the air cylinder 2. The piston rod 4 is provided. The inside of the air cylinder 2 is divided into a first air chamber 5 on the piston rod 4 side and a second air chamber 6 on the opposite side before and after the piston 3, and air ports formed at both ends of the air cylinder 2. The internal air pressure is controlled by the switches 7 and 8.

On the other hand, the peripheral surface of the piston 3 has
A permanent magnet 9 is provided. Further, on the peripheral surface of the air cylinder 2, the sensor S _H , which is opposed to the piston 3 at the position of the most extended state, the intermediate state, and the most retracted state of the piston rod 4, is provided. S ₀ and S _L are attached, and sensors S _H and S
The _0, S _L, so that detecting the permanent magnet 9.

In the present invention, the pressure of the first air chamber 5 and the second air chamber 6 is adjusted by the air control mechanism, so that the pistons 3 are provided with the sensors S _H , S ₀ , S S.
_The stop control is performed at the position detected by each of _L.

The air control mechanism will be described. The air control mechanism includes solenoid valves V ₁ and V ₂ , a pressure reducing valve 10 (pressure adjusting device), an air source P, a central control device CPU (or a sequencer), and the like, and the solenoid valves V ₁ and V ₂ are air ports. The position is converted into a position where the air source P is connected to the air source P, and a position where the air in the air chambers 5 and 6 is discharged to the atmosphere side. Also,
A pressure reducing valve 10 capable of adjusting the air pressure is interposed between the solenoid valve V ₂ and the air source P, so that the air pressure communicated with the second air chamber 6 becomes lower than the pressure of the air source P. So that it can be adjusted.

[0014] That is, in the pneumatic control system of the present invention, an intermediate stop position the permanent magnets 9 of the piston 3 is sensed by the sensor S _0, although the piston rod 4 is intended to stop control, this means As described later, high-pressure air is supplied to each of the air chambers 5 and 6 to equalize the force before and after the piston 3 to stop the piston rod 4.

However, in order to equalize the forces applied to the front and rear of the piston 3, if the same pressure source is communicated with both the air chambers 5, 6, the piston with the rod and the piston without the rod have the same pressure source. Since the pressure receiving area differs between the front and back surfaces of the piston 3, the force on the second air chamber 6 side is inevitably increased, and the forces applied to the front and back surfaces of the piston cannot be equalized, and the piston moves. Therefore, the pressure reducing valve 10 serving as a pressure adjusting device is adjusted in advance to reduce the pressure on the second air chamber 6 so that the force applied to the front and back of the piston can be set to be equal.

In the above configuration, various internal pressure states are generated by separately controlling the air chambers 5 and 6 by the solenoid valves V ₁ and V ₂ , respectively. Although the solenoid valve V ₁ and the solenoid valve V ₂ use a 5-port 4-way solenoid valve, any solenoid valve that can be selectively converted into a pressurized state and an exhaust state may be used in practice.

In such a configuration, the operation control command of the piston rod 4 is issued by the central control unit CPU (or sequencer), and its mode will be described. The above-described air control mechanism includes an operation mode in which pressure is supplied to only one of the air chambers 5 and 6,
And stopping the piston 3 at an intermediate position by equalizing the force applied to the front and rear of the piston 3 by supplying pressure to the air chamber. This selective switching is performed by a manual switching switch, or when the air cylinder device 1 is used for selecting defective workpieces on the transport path, the operation is switched in cooperation with other determination means. . In this way, in addition to manual switching, operation switching can be performed in cooperation with various mechanisms.

In the above operation mode, the piston rod 4
To advance the switches the solenoid valve V _1, a first air chamber 5 communicates with the atmosphere, and to switch the solenoid valve V _2, the second air chamber 6, the air source through a pressure reducing valve 10 Communicate with P.
Thereby, the piston 3 slides forward due to the pressure in the second air chamber 6. When the sensor S ₀ is turned on operates, as will be described later, instead only the solenoid valve V ₁ is off, the first air chamber 5 communicates with the air source P, and a middle operating configuration, the front and rear of the piston 3 The applied force becomes equal, and the piston rod 4 stops moving. Further, after this, to be advanced switches the solenoid valve V _1, so that the first air chamber 5 communicates with the atmosphere. When the sensor S _H is turned on, the piston rod 4 is determined that the maximum protraction position by such ON operation, for example if necessary, working like peripheral mechanism of the transport path moves on to the next operation. That is, the sensor S _H is used for setting the maximum extension position of the piston rod 4 and controlling the timing of another mechanism.

Further, in order to retract the piston rod 4, by switching the solenoid valve V _1, air source P to the first air chamber 5
It communicates with, and to switch the solenoid valve V _2, the second air chamber 6 communicates with the atmosphere. As a result, the piston 3 slides rearward due to the pressure in the first air chamber 5. And the sensor S
_{When L} is turned on, it is determined that the piston rod 4 has reached the maximum retracted position by the on operation, and the sensor S
_{The process proceeds} to the next operation as necessary similarly to _L. Incidentally, the way may cause the intermediate operating configuration by the on operation of the sensor S _0. That is, in the above-described forward or backward movement of the piston rod 4, an intermediate operation mode can be appropriately interposed depending on the operation.

When the sensor S ₀ is turned on during the forward or backward movement of the piston rod 4, the intermediate operation mode drives the solenoid valve V ₁ or the solenoid valve V ₂ , and the air on the side communicating with the atmosphere is actuated. This is performed by connecting the chambers 5 and 6 to the air source P. At this time, the pressure of the second air chamber 6 is made slightly lower than the source pressure of the air source P by adjusting the pressure reducing valve 10 described above, so that an equal force is applied inside and outside the piston rod 4. . As described above, the piston rod 4 stops at the intermediate position due to the pressure balance between the first air chamber 5 and the second air chamber 6. Therefore, since it is an air cushion type stopping method, the shock at the time of stopping can be absorbed.

Since the above-mentioned intermediate position stop is based on the pressure balance, a slight delay may occur. Therefore, the sensor S ₀ a little than a predetermined stop position, the rearward (to or forward) to move, may be the switching of pressure in early. Although this stop control has a slight error, the stop control has a control operation that can tolerate such an error and can be used for a wide range of applications.

Further, in the embodiment described above, the sensor S _0, was to produce a single intermediate stop position, the sensors S ₀ in plurality, as to produce a plurality of intermediate stop positions You may do it. Further, with the movable sensor S _0, and thus capable of adjusting the intermediate stop position at will.

In the piston rod 4 which operates as described above, various jigs 11 can be disposed at the tip thereof, whereby the work can be sorted by changing the stroke of the piston rod 4, Or, attach the air cylinder device 1 vertically and distribute it to various heights.
It can be used for various applications.

[0024]

As described above, according to the present invention, the pressure is supplied to the air chambers 5 and 6 on both sides of the piston which slides in the air cylinder, and the forces applied to the front and rear of the piston 3 are equalized. Is stopped at an optional intermediate position. 1) The pressure is controlled, and a lock mechanism is not provided to stop the piston 3. Therefore, the structure is simple and inexpensive. 2) Since it is an air cushion type stop method, it can absorb the shock at the time of stop. 3) By setting the sensor S ₀ etc. at appropriate positions,
The position can be adjusted at will and a plurality of intermediate stop positions can be set. 4) As described above, the structure is simple and inexpensive, positioning is easy, and any number of stop positions can be set, so that versatility is high.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an air cylinder device 1 and its air control mechanism.

[Explanation of symbols]

1 air cylinder device 2 cylinder 3 piston 4 the piston rod 5 first air chamber 6 second air chamber 9 the permanent magnet 10 pressure reducing valve S _H, S _0, S _L sensors V _1, V ₂ solenoid valve P air source

Claims (2)

[Claims] A piston sliding in an air cylinder;
An air cylinder device having a cylinder rod having a base end fixed to one side of the piston and protruding outside the cylinder,
A first air chamber on the piston rod side located before and after the piston, and an air control mechanism for performing pressure control of the second air chamber on the opposite side, wherein the air control mechanism applies pressure to only one of the air chambers. It is characterized by selectively executing a supply mode and a stop mode in which pressure is supplied to both air chambers to stop the piston at an intermediate position by equalizing the force applied before and after the piston. Air cylinder device. 2. The first air chamber and the second air chamber are communicated with the same air source, and a pressure adjusting device is inserted into the air supply passage. 3. The air cylinder device according to claim 1, wherein the pressure in the one air chamber is slightly higher than the pressure in the second air chamber so as to equalize the force applied to the front and rear of the piston.