JPH06200908A - Air leak check valve - Google Patents

Abstract

PURPOSE:To detect in an early stage whether air of an air supplying control valve is leaked or not. CONSTITUTION:An air leak check device consists of a housing 12 which can be seen through, and having a cylindrical space 16 extending vertically in the inside of the housing 12 and a float member 15 vertically movable inserted and arranged in the cylindrical space 16. The cylindrical space 16 is separated into an upper side space 16a and bottom side space 16b by the float member 15. A communicating passage 11a communicated with air discharging port of an air supplying control valve 20 is opened to the bottom end part of the cylindrical space 16, and an exhaust port 12a opened to outside air is formed on the upper part of the cylindrical space 16. When air exceeding a prescribed flow amount is supplied from the air supplying control valve 20 into a bottom side space 16b, a float member 15 is moved upward in the cylindrical space 16 by air pressure. When the supplied air amount is a prescribed flow amount or less, the float member 15 is moved downward in the cylindrical space 16 by its own weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device capable of detecting the presence or absence of air leakage (air leakage) from an air supply control valve used for controlling the operation of an air-actuated actuator (hereinafter simply referred to as actuator). Regarding

[0002]

2. Description of the Related Art Such an air supply control valve is used for controlling the operation of actuators such as air cylinders for driving various equipments and devices in factory production lines and the like. In factories and the like, a compressor or the like that creates a predetermined pressure of air is used as an air supply source, and the air from this air supply source is centrally supplied to the drive actuators of a plurality of devices and apparatuses. Many. Each actuator is provided with an air supply control valve for controlling the air supply, and the air supply control valve is driven by a solenoid or the like to control the operation of the actuator.

[0003]

In such an air supply control valve, when the spool and the diaphragm are worn or damaged and an air leak occurs, there is a problem that the operation control of the actuator by the valve cannot be performed. When such a malfunction occurs in the production line of the factory as described above, there is a problem that not only the production is stopped at the portion where the operation by the actuator is performed, but also the entire production line is stopped.

In view of the above problems of the present invention, the air leak in the air supply control valve does not suddenly occur from the normal state, but the air leak amount gradually increases as the spool and the diaphragm are worn and damaged. In view of the fact that when the air leak becomes large enough that the actuator operation cannot be controlled, it will lead to malfunction, and an air leak check with a configuration that allows early detection of the presence or absence of an air leak in the air supply control valve. The purpose is to provide a device.

[0005]

In order to achieve such an object, in the present invention, a see-through (that is, transparent or semi-transparent) housing having a vertically extending cylindrical space therein is provided. An air leak check device is composed of a float member vertically movably inserted in a cylindrical space, and the float member divides the cylindrical space into a space above and below the float member. ing. Then, a communication passage communicating with the air discharge port of the air supply control valve opens at the lower end of the cylindrical space,
An exhaust port that opens to the outside air is formed in the upper part of the cylindrical space, and the float member is movable above this exhaust port. When air exceeding a predetermined flow rate is supplied to the lower space from the air supply control valve via the communication passage, the float member is moved upward in the cylindrical space by this air pressure. However, when the supplied air amount is less than or equal to a predetermined flow rate, the float member is configured to move downward in the cylindrical space due to its own weight.

[0006]

In the air leak check device having such a structure, when the air supply control valve is in a steady state (when the actuator is inactive), the air discharge port leaks (leaks) from a gap between the spool and the housing. Only the air is exhausted. Here, the above-mentioned predetermined flow rate (flow rate at which the float member moves upward in the cylindrical space to generate air pressure) is set to a value in the vicinity of the upper limit value of the leak flow rate allowed by the air supply control valve in a steady state. Therefore, when the air supply control valve is normal, the float member is not moved upward by the air leaking from this valve in a steady state, and the float member remains in the downward moving state in the cylindrical space. is there.

On the other hand, when the amount of air leak gradually increases due to progress of wear and damage of the spool and diaphragm, and when the amount exceeds a predetermined flow rate (allowable flow rate), the air pressure generated in the lower space by this air leak. In response to this, the float member moves upward in the cylindrical space. The housing with a cylindrical space is transparent or translucent and can be seen through.
The position of the float can be visually confirmed. Therefore, when the air supply control valve is in a steady state, the presence or absence of air leak (air leak exceeding a predetermined flow rate) can be easily confirmed only by visually checking the position of the float member. And when the float member is moving upward, the air leak amount is above the allowable limit,
The air supply control valve is replaced and repaired, whereby malfunction of the air cylinder can be prevented.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an operation control device in which an air supply control valve 20 controls the operation of an air cylinder 25 as an actuator, and the air leak check device 10 according to the present invention is attached to the air supply valve 20. . The air cylinder 25 is configured such that a piston 27a is slidably inserted in the cylinder tube 26 to the left and right, and a piston rod 27b is projected outward from the cylinder tube 26. The space inside the cylinder tube 26 is divided into a right air chamber 28a and a left air chamber 28b by the piston 27a. When air is supplied to the right air chamber 28a, the piston 27a
When the rod 27b is moved to the left and air is supplied to the left air chamber 28b, the piston 27a and the rod 27b are
Is moved to the right.

This air supply is performed by switching and controlling the air of a predetermined pressure supplied from an air supply source (for example, a compressor) 30 through a line 31 by an air supply control valve 20. The valve 20 is provided with a slidable spool 22 in a valve housing 21. The spool 22 is constantly urged to the right by a spring 24 and can be pressed to the left by a solenoid 23. .

When the solenoid 23 is deenergized and there is no pressing force from the solenoid 23, the spool 22 is moved to the right by the urging of the spring 24 (state of FIG. 1).
Therefore, the air from the air supply source 30 is supplied to the left air chamber 28b of the air cylinder 25 through the line 32b. As a result, the piston 27a and the rod 27b are moved to the right and stopped when they are moved to the stroke end to the right. On the other hand, when the solenoid 23 is turned on, the pressing force from the solenoid 23 overcomes the urging force of the spring 24, the spool 22 is moved to the left, and the air from the air supply source 30 is discharged through the line 32a. The air is supplied to the right air chamber 28b of the cylinder 25. This allows the piston 2
7a and the rod 27b are moved to the left and stopped when they are moved to the end of the stroke.

As shown in FIG. 2, the valve housing 2
1 has an air discharge port, which is connected to the air leak check device 10 via a discharge hose (communication passage) 33. When the piston 27a and the rod 27b of the air cylinder 25 are slid by the on / off control of the solenoid 23 as described above, the air discharged from the air chamber on the side opposite to the air supply side is guided to the air discharge port. The discharged air is discharged to the air leak check device 10.

Incidentally, the piston 27a and the rod 27b
In the state where it is stopped when it is moved to the stroke end (this is called a steady state), the left and right air chambers 28
Since there is no air discharge from a and 28b, theoretically the amount of air discharged from the air discharge port to the air leak check device 10 via the discharge hose 33 becomes zero. However, some air leak occurs from the gap between the housing 21 and the spool 22, and this air leak is guided to the air leak check device 10 from the discharge port through the discharge hose 33.

As shown in FIG. 2, the air leak check device 10 includes a bottom member 11 and a hollow cylindrical pipe housing 12 mounted on the bottom member 11.
A cover member 13 that covers the upper end of the pipe housing 12, and a float ball 15 that is inserted and arranged in a cylindrical space 16 that extends vertically inside the pipe housing 12. A discharge hose 33 is connected to the bottom member 11, and an opening passage 11a connected to the discharge hose 33 is formed with an opening on the upper surface. Therefore, the air discharge port of the air supply control valve 20 communicates with the bottom of the cylindrical space 16 via the discharge hose 33.

The pipe housing 12 is a transparent or translucent member made of acrylic resin or the like, and has a 4
The individual exhaust ports 12a are formed so as to penetrate therethrough. Therefore, the cylindrical space 16 communicates with the outside air through the exhaust port 12a at the upper part. The float ball 15 is made of, for example, a lightweight hollow ball such as a ping-pong ball, and is loosely inserted in the cylindrical space 16 of the pipe housing 12. This float ball 15 allows a cylindrical space 16
Of the float ball 15 is divided into an upper space 16a and a lower space 16b. As shown in FIG. 3, the inner diameter D of the cylindrical space 16 is slightly larger than the outer diameter d of the float ball 15, and the float ball 15 can freely move up and down in the cylindrical space 16. ing. Therefore, the float ball 15 is normally moved downward by its own weight and placed on the bottom member 11 (the state shown in FIG. 2).

From this state, the exhaust air from the air supply control valve 20 is discharged through the discharge hose 33 to the lower space 16b.
When the air flows in, the float member 15 is pushed up by this air pressure and moves upward in the cylindrical space 16. Then, when the attached funnel member 15 is moved upward beyond the exhaust port 12a, the air in the lower space 16b is discharged to the outside.
Therefore, every time the air cylinder 25 is operated by the air supply control valve 20, the air discharged from the air cylinder 25 is discharged through the air leak check device 10, and the float member 15 moves up and down each time.

However, in the state where the air cylinder 25 moves to the stroke end and stops, and is in a steady state, the air discharge is stopped and the float member 15 moves downward. However, when the spool and diaphragm of the air supply control valve 20 are worn or damaged and the amount of air leak increases, the leak air flows into the lower space 16b, and therefore the float member 15 is moved upward by the leak air even in a steady state. It Since the pipe housing 12 is transparent or semi-transparent and the inside can be seen through, the fact that the float member 15 is moving upward in a steady state shows that the amount of air leakage from the air supply control valve 20 has increased. You can easily know. Then, at this time, the air supply control valve 20 can be repaired or replaced to prevent the occurrence of a trouble that makes the air cylinder 25 inoperable.

In order to move the float member 15 upward when the amount of air leak increases, the difference Δd (= the outer diameter d of the float member 15 with respect to the inner diameter D of the cylindrical space 16).
D-d), that is, the radial clearance needs to be managed. If this difference Δd is made small, the float member 15 moves upward due to a slight increase in the amount of air leak, so that it is easy to find a slight air leak. However, as shown in FIG. 3, the oil film 12b is attached to the inner surface of the cylindrical space 16, and if the difference Δd is too small, the resistance of the oil film 12b causes
There is a problem that the float member 15 once moved up does not move down even when there is no air leak, and it becomes impossible to accurately check the air leak.

From the above, the float member 15 moves upward only when an air leak exceeding the allowable air leak amount of the air supply control valve 20 occurs, and when there is no air leak, the float member 15 moves downward by its own weight. The magnitude of the difference Δd is set so that the difference can be achieved. In the case of this example, this difference Δd is 0.2 to 0.4 mm.
It is set to a degree. However, the difference Δd is not limited to this, and may be appropriately set in accordance with various conditions, for example, the size of the inner diameter D of the cylindrical space 16, the weight of the float member 15, and the like.

The air leak check device of the present invention may be constructed as shown in FIG. This air leak check device 5
0, the bottom member 51, the pipe housing 51, and the cover member 53 have the same configuration as the air leak check device 10 described above, but is different from the above device in that the float member 55 is formed in a piston shape. The piston-like float member 55 is provided in the cylindrical space 5 of the pipe housing 15.
6 is slidably inserted in the vertical direction, and has a small hole 55a penetrating vertically in the center thereof.

This small hole 55a plays a role corresponding to the gap of the difference Δd in the above-mentioned device 10, and when the air leak amount is less than a predetermined amount (the upper limit of the allowable air leak amount of the air supply control valve 20), this small hole 55a. Since the leak air flows through the float member 55, the float member 55 does not move upward. Then, when the air leak amount exceeds a predetermined amount, the float member 55 is moved upward by the air pressure generated in the lower space, so that it is possible to easily check the increase of the air leak amount by looking at this.

[0021]

As described above, according to the present invention,
An air leak check device is configured by inserting and arranging a float member in a cylindrical space of a see-through housing so that the float member can move up and down, and exhaust air from an air supply control valve flows into the lower end of the cylindrical space. It is like this. Then, when air exceeding a predetermined flow rate is supplied to the lower space from the air supply control valve through the communication passage, the float member is moved upward in the cylindrical space by this air pressure, and the supplied air amount is set to a predetermined value. When the flow rate is lower than the flow rate, the float member is configured to move downward in the cylindrical space by its own weight.

When the spool of the air supply control valve and the diaphragm are worn and damaged, the amount of air leak gradually increases, and when the amount exceeds a predetermined flow rate (allowable flow rate), the air leak occurs in the lower space. Since the float member moves up in the cylindrical space under the air pressure,
When the air supply control valve is in a steady state, the presence or absence of an air leak (air leak exceeding a predetermined flow rate) can be easily confirmed only by visually checking the position of the float member. In the steady state, when the float member is moving upward, the air leak amount is over the allowable limit.Therefore, the air supply control valve is replaced and repaired. It is possible to prevent problems such as the production line used from stopping.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an air cylinder operation control device equipped with an air leak check device according to the present invention.

FIG. 2 is a partial cross-sectional view showing the air leak check device and the air supply control valve.

FIG. 3 is an enlarged cross-sectional view showing this air leak check device.

FIG. 4 is a cross-sectional view showing another example of the air leak check device according to the present invention.

[Explanation of symbols]

 10 Air Leak Check Device 12 Pipe Housing 15 Float Member 16 Cylindrical Space 20 Air Supply Control Valve 23 Solenoid 25 Air Cylinder 30 Air Supply Source

Claims (2)

[Claims] 1. An apparatus for checking the presence or absence of an air leak in an air supply control valve for controlling the air supply from an air supply source to an actuator, the housing having a vertically extending cylindrical space therein and having a see-through internal space. And a float member inserted in the cylindrical space so as to be vertically movable, and the float member divides the cylindrical space into a space above and below the float member. A communication passage that communicates with an air discharge port of the air supply control valve is opened at a lower end of the cylindrical space, and an exhaust port that opens to the outside air is formed at an upper portion of the cylindrical space. Is movable to the upper side of this exhaust port, and air exceeding a predetermined flow rate is supplied to the lower space from the air supply control valve via the communication passage. And the float member is moved upward in the cylindrical space by the air pressure generated in the lower space, and the air flow rate supplied from the air supply control valve to the lower space via the communication passage is The air leak check device, wherein the float member is configured to move downward in the cylindrical space due to its own weight when the flow rate is equal to or lower than the predetermined flow rate. 2. The air leak check device according to claim 1, wherein the predetermined flow rate is set to a value near an upper limit value of the leak flow rate allowed in the steady state of the air supply control valve.