JP2003121293A - Detection method of air leakage in air passage changeover device and air leakage detection means - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection method and the like capable of easily and rapidly detecting, as compared with a conventional example, air leakage in an air passage changeover device with a plurality of passage selector valves built in a passage forming member. SOLUTION: The passage forming member 10 of the air passage changeover device has an intake passage 12, exhaust passages 13 and 14, and plural couples of output passages 16 and 17 connected to a driving apparatus. In each passage selector valve 30 connected to the passage forming member, an air inlet 32, the exhaust passages 13 and 14 and output passages 16 and 17 are formed and a valve element 40 for making the air inlet communicate with the on-side exit port and the one-side exhaust port is included. An air leakage detection means 45 is inserted into one of the exhaust passages 13 and 14 and thereafter gradually pulled out, so that the air leakage in each passage selector valve 30 is detected by examining the loudness of sound at that time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to detection of air leakage in an air flow path switching device in which a plurality of flow path switching valves for switching the air flow paths are incorporated in a flow path forming member having an air flow path formed therein. The present invention relates to a method and an air leak detection tool used in the detection method.

[0002]

2. Description of the Related Art A pneumatic device is one type of fluid pressure device.
For air pressure, output can be adjusted stepwise by adjusting pressure, speed and rotation speed can be set steplessly by adjusting flow rate, environment does not pollute the environment even if exhaust gas escapes to the atmosphere, It has the advantage of being able to properly control the flow rate and pressure with an air source. These are widely used because of their advantages.

The pneumatic device converts mechanical energy into pressure energy of air by an air compressor, controls the pressure, and then supplies the pressure energy to the actuator to perform mechanical work. The pneumatic device usually includes an air pressure source, various control valves (direction control valve, flow rate control valve, etc.), and an actuator.

A pneumatic cylinder, which is one of the actuators, is composed of a cylinder and a piston that is slid in the cylinder, and drives a predetermined device by the movement of the piston. A flow path switching valve is used to drive the piston in one direction or the other. The air passage is switched by the passage switching valve so that the compressed air is supplied to one chamber of the piston in the cylinder and is discharged from the other chamber.

Usually, in a production line, a plurality of devices are driven simultaneously by a plurality of pneumatic cylinders or with a time difference. Then, since a plurality of pneumatic cylinders are driven by compressed air supplied from the same compressed air source, an air flow path switching device in which a plurality of flow path switching valves are incorporated in a flow path forming member is used.

FIG. 4 shows an example of a conventional air flow path switching device. This air flow path switching device comprises a flow path forming member 80 and a plurality of flow path switching valves 90. The flow path forming member 80 is formed by stacking a plurality of manifolds 81, an air supply flow path 82 is formed in a central portion, and a pair of exhaust flow paths 83a is formed on both left and right sides.
And 83b are formed. The air supply channel 82 extends from the upper end of the channel forming member 80 to near the lower end, and the upper end opening is connected to an air source (not shown). Exhaust channel 83a, 83
b extends from the lower end of the flow path forming member 80 to near the upper end.

Each manifold 81 has a pair of output channels 8
4a and 84a are formed, and the chambers 88a and 88 on one side and the other side of the pneumatic cylinder 87 are formed by the tubes 86a and 86b.
b respectively.

Each flow path switching valve 90 has a supply port facing the supply flow channel 82, a pair of exhaust ports facing the exhaust flow channels 83a and 83b, and a pair of outputs facing the output flow channels 84a and 83b. A mouth is formed and includes a valve body (neither shown) that moves axially. The air flow path is switched by moving the valve body. For example, when the piston 89 is moved in the x direction, the air supply passage 82 is connected to the output passage 84a by the valve body, and the compressed air is supplied to the chamber 88a at one end through the one pipe 86a. At the same time, the air in the chamber 88b at the other end is transferred to the other pipe 86b, the output passage 84b and the exhaust passage 84b.
Exhausted through.

Air leaks between the manifold 81 and the flow path switching valve 90 due to damage to the flow path switching valve 90 or damage to the gasket interposed between each manifold 81 and each flow path switching valve 90. Sometimes. Most of the leaked air flows from the supply flow path 82 to the exhaust flow path 83a and / or 83b.
It is distributed to and exhausted.

[0010]

The air leak can be found by observing the flow rate of air with a meter of an air flow valve attached to the air supply passage 82. However, it is not known which of the six flow path switching valves 90 is leaking.
Therefore, conventionally, the uppermost flow passage switching valve 90 is removed from the manifold 81, and instead, a plate member (not shown) having the same shape as the flow passage switching valve 90 closes the opening of the air passage of the manifold 81. . Then, compressed air is supplied.

As a result of observing the air flow rate, if air leakage (flow rate is smaller than normal when the scale of the flow meter is smaller than normal) is detected,
The plate member is removed, the gasket is repaired or replaced, and the flow path switching valve 90 is attached. If no air leak is found, similar air leak detection is performed for the flow path switching valve 90 at the next stage. Thus, the removal of the flow path switching valve, the mounting of the plate member, the observation of the air circulation amount, the removal of the plate member and the mounting of the flow path switching valve are repeated for each stage.

However, this work is very troublesome, and it takes a lot of time and labor to detect it, and the operator is tired. Further, air continues to leak until the flow path switching valve causing the air leakage is specified, which goes against the demand for energy saving which has been attracting attention in recent years.

The present invention has been made in view of the above circumstances. Air leaks in an air flow path switching device in which a plurality of flow path switching valves are incorporated in a flow path forming member are easier and shorter than conventional examples. The object is to provide a detection method that can detect the

[0014]

The inventor of the present invention has completed the present invention with the idea of identifying a flow path switching valve in which air leakage is occurring by a sound-sensing type leak detection tool. That is, in the flow path switching valve in which air leakage occurs, most of the air in the air supply flow path flows into the exhaust flow path, and a louder sound is generated than the sound of the flow path switching valve in which air does not leak. So
This phenomenon is used.

That is, the present invention is a flow path forming member having an air supply flow path connected to an air source, a pair of exhaust flow paths, and a plurality of pairs of output flow paths connected to a driving device; A plurality of flow passage switching valves attached to the forming member, each of which has an air supply port communicating with the air supply passage, a pair of exhaust ports communicating with a pair of exhaust flow channels, and an output flow channel of each pair. It is premised on an air flow path switching device including a plurality of flow path switching valves each having a corresponding output port formed therein and connecting the air supply port to the one output port and the one exhaust port. In such an air flow path switching device, in order to detect an air leak in each flow path switching valve, an air leak detection tool is inserted into one exhaust flow path and then pulled out in stages, and the loudness at that time is examined. It is characterized by This makes it possible to identify the flow path switching valve in which the air leakage has occurred.

Further, the air leakage detection tool of the present invention has a detector, a sound collector extending from the detector, a thickness connected to the sound collector, and a thickness that can be inserted into the exhaust passage of the passage switching device. And a tubular insertion portion having a length. This air leakage detection tool can be inserted into the exhaust passages of various thicknesses, lengths and shapes by changing the thickness, length and shape of the insertion portion.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION <Air Leak Detection Method> Air flow path switching device The air flow path switching device comprises a flow path forming member and a plurality of flow path switching valves. Of these, the flow path forming member preferably comprises a plurality of manifolds. The plurality of manifolds may be stacked vertically or horizontally.

There are no particular restrictions on the arrangement of the air supply passage, both exhaust passages, and the plurality of output passages of the passage forming member. For example,
It is possible to form the air supply passage in the central portion, form the exhaust passages on both sides thereof, and form the output passages between the air supply passage and the exhaust passages. Further, the output passages may be formed on both sides of the air supply passage formed in the central portion, and the exhaust passage may be formed between the air supply passage and the output passage.

The air supply passage, the exhaust passage and the output passage may extend in the vertical direction or may extend in the horizontal direction. The shape may be linear or may be slightly curved.

When the flow path forming member is formed of a plurality of manifolds, an air supply flow path portion forming a part of the air supply flow path and an exhaust flow forming a part of a pair of exhaust flow paths in each manifold. A channel portion and a pair of output channels can be formed.

Each of the plurality of flow path switching valves may be electromagnetically operated or pilot driven. The valve body connects the air supply port to one of the output ports and the other output port to the other exhaust port. Thereby, the predetermined air flow paths of the flow path forming member are communicated with each other.

The number of flow path switching valves is equal to the number of manifolds. There is no particular restriction on the number, but the number can be about 2 to 10.

In order to detect air leakage, a sound-sensing air leakage detection tool inserted in one exhaust passage is pulled out in stages, and when a loud noise, that is, air leakage is confirmed, air leakage detection is performed at that time. You can attach a ring to the tool and check the scale that was previously engraved on the air leak detection tool.

The air leakage detection tool can be inserted directly into the exhaust passage, or a thin tubular insertion portion attached to the tip can be inserted. The loudness of the sound is detected by the meter of the detector.

The air leak detection tool is inserted into the exhaust passage on the side where compressed air is not originally discharged. A muffler can be attached to the exhaust passage on the exhaust side to prevent exhaust noise. The air pressure of the compressed air during detection can be lower than the air pressure during operation. <Air Leakage Detector> A general-purpose detector and sound collector can be used as the air leak detector. One end of the tubular insertion portion is airtightly connected to the sound collecting portion, and the other end is open. The insertion portion may be composed of a single member, but may also be composed of a large diameter member on the sound collector side and a small diameter member on the insertion side. The insertion part may be made of metal or resin, and in the latter case, it can have flexibility.

It is possible to prepare a plurality of insertion portions having different thicknesses, lengths and shapes, and use the optimum insertion portion according to the thickness, length and shape of the exhaust passage.

[0027]

EXAMPLES The present invention will be described in more detail based on the following examples. Air Flow Path Switching Device The air flow path switching device shown in FIGS. 1 and 2 includes a flow path forming member 10 and a plurality of (here, six) flow path switching valves 30. Among these, the flow path forming member 10 includes a plurality of manifolds 11 that are vertically stacked.

An air supply passage 1 is provided at the center of the passage forming member 10.
2 is formed, and the first exhaust flow path 13 and the second exhaust flow path 14 are formed on the left side and the right side, respectively. The air supply passage 12, the first exhaust passage 13 and the second exhaust passage 14 are provided with an air supply passage portion 12a formed in each manifold 11 and a first exhaust passage 13.
It is composed of the exhaust flow passage portion 13a and the second exhaust flow passage portion 14a.
The air supply passage 12 extends from the upper end of the passage forming member 10 to near the lower end, and the upper end opening is connected to a compressed air source (not shown). The first and second exhaust flow paths 13 and 14 extend from the lower end of the flow path forming member 10 to near the upper end.

In each manifold 11, the first output flow passage 16 is provided between the air supply flow passage 12a and the first exhaust flow passage 13.
Are formed, and the air supply flow passage portion 12a and the second exhaust flow passage portion 14a are formed.
The second output flow path 17 is formed between and. The first output flow passage 16 is connected to the chamber 22 on one side of the piston 21 of the pneumatic cylinder 20 by the first pipe 18, and the second output flow passage 17 is provided.
Is connected to the chamber 23 at the other end by the second pipe 19.

As shown in FIG. 2, each of the six flow path switching valves 30 corresponding to each of the plurality of manifolds 11 has a valve case 31 and a valve body 40 movably housed in its hollow portion. It consists of and. An air supply port 32 is opened in the center of the hollow portion of the valve case 31, and a first exhaust port 33 and a second exhaust port 34 are opened on the left and right sides thereof, respectively. Further, the first gap is provided between the air supply port 32 and the first exhaust port 33.
The output port 36 is open, and the second output port 37 is open between the air supply port 32 and the second exhaust port 34.

The air supply port 32 is in the air supply flow passage portion 12a, and the first exhaust port 33 and the second exhaust port 34 are in the first exhaust flow passage portion 13.
a and the second exhaust flow path portion 14a, the first output port 36 and the second output port 37 have the first output flow path 16 and the second output flow path 17 respectively.
Are facing each other. Further, between the air supply port 32 and the first output port 36 and the second output port 37, and between the first output port 36 and the second output port 37 and the first exhaust port 33 and the second exhaust port 34. A valve seat portion 39 is formed in each.

The valve body 40 has four large diameter portions 41 and is moved to any of the left position, the intermediate position and the right position by the electromagnetic coil. The air flow path is switched depending on whether the large diameter portion 41 of the valve body 40 is seated on the valve seat portion 39 or the air supply port 32 or the like is closed. That is, each flow path switching valve 30 is of a 5-port 3-position type.

When the pneumatic cylinder 20 is operated, for example, when the piston 21 is moved in the x direction (leftward), the valve body 4
Move 0 to the right. As a result, the air supply port 32 communicates with the air supply flow passage 12a of the manifold 11, and the first exhaust port 33 and the second exhaust port 34 are respectively connected to the first exhaust flow passage 13.
a and the second exhaust flow path portion 14a, and the first output port 36
The second output port 37 communicates with the first output flow channel 16 and the second output flow channel 17, respectively. As a result, the compressed air supplied from the air supply passage 12 is supplied to the air supply port 32 and the second output port 3
7 to the second output flow path 17, and is supplied to the right chamber 23 of the pneumatic cylinder 20 via the second pipe 19. At the same time, the air in the left chamber 22 returns to the first output flow path 16 through the first pipe 18, and the first output port 36 and the first exhaust port 33.
And then exhausted from the first exhaust flow path 13.

When the piston 21 of the pneumatic cylinder 20 is moved in the direction opposite to the x direction, the valve body 40 moves to the left and the compressed air flows in the direction opposite to that described above. Further, when the valve body 40 is at the intermediate position, air is not supplied to any of the chambers 22 and 23. Air Leak Detection Tool As shown in FIG. 3, an air leak detection tool 45 used for detecting an air leak is a detector 46, a sound collector 48 connected to the detector 46, and an insertion portion 50 attached to the tip thereof. It consists of and. The detector 46 displays the sound level on a meter and allows an operator to listen with earphones. Detector 4
6 and the sound collector 48 are general-purpose products.

The insertion portion 50 includes a large diameter tube 51, a reducer 52, and a small diameter tube 53. The large-diameter tube 51 is made of resin and has an inner diameter into which the sound collector 48 can be inserted in an airtight state.

The small-diameter tube 53 is made of resin or metal, and has a length and an outer diameter such that it can be inserted up to the upper ends of the exhaust passages 13 and 14 of the passage forming member 10. In addition, small diameter tube 5
A plurality of O-rings 54 are fitted to the unit 3, and can be moved and positioned at a predetermined position. The reducer 52 connects the large diameter tube 46 and the small diameter tube 48 in an airtight state. Air Leak Detection Method Next, a method of detecting an air leak by the air leak detection tool 45 in the air flow path switching device will be described.

An air flow meter is attached on the air supply flow path 12 of the flow path forming member 10, and the presence or absence of air leakage is confirmed by observing the meter. If an air leak is confirmed (the meter reading is lower than during operation), the air leak is detected according to the present invention.

At the time of detection, the valve body 40 is moved to the left so that the compressed air flows into the first output passage 16 and the second output passage 17
And return compressed air.

In this state, the compressed air should originally be discharged from the second exhaust passage 14 and not from the first exhaust passage 13. However, if the air supply passage 12 and the second exhaust passage 13 are communicated with each other due to damage to the gasket, the first
Compressed air leaks from the exhaust passage 13. Therefore, as shown by the chain double-dashed line in FIG. Leak detection tool 45
And then supply compressed air. The pressure of the compressed air may be the same as the air pressure when the air cylinder 20 is operating, but here, compressed air having a lower air pressure is used.

More specifically, the detector 46 is turned on, the earphone is attached to the ear, the small-diameter tube 53 is inserted deepest into the first exhaust flow path 13, and the meter of the detector 46 is viewed while listening to the earphone. Air leakage is detected from the uppermost flow passage switching valve 30. Then, the small diameter tube 53 is gradually pulled out from the first exhaust passage 13. When a loud sound is confirmed by the meter and earphone, the small-diameter tube 5
The O-ring 54 is positioned at a position corresponding to the lower end surface 10a of the flow path forming member 10 on the upper part 3. Thereafter, the same procedure is performed to detect the air leakage up to the lowermost flow passage switching valve 30.

After detection of air leakage in all the flow path switching valves 30, the small-diameter tubes 53 are completely drawn out from the first exhaust flow path 13, arranged side by side with the flow path forming member 10, and fitted thereon. Based on the position of the O-ring 54 thus determined, the flow path switching valve 30 in which the air leakage has occurred is estimated. Then, the gasket of one or two abnormal flow path switching valves 30 in which an abnormality has occurred may be repaired and replaced.

Incidentally, the valve body 40 is moved in the direction opposite to the above-mentioned direction to exhaust the gas from the first exhaust flow path 13, and the second exhaust flow path 1
The air leak can also be detected by inserting the air leak detection tool 45 into 4.

According to this embodiment described in detail above, the small-diameter tube 53 of the leak detection tool 45 is inserted into the first exhaust flow path 13, and the flow path is simply drawn out while observing the meter of the detector 46 and the like. The air leakage can be easily detected without removing the switching valve 30. The sound-sensing air leak detection tool can reliably detect even a small amount of air leak.

Further, the air leakage detecting tool 45 is obtained by adding a large-diameter tube 51, a reducer 52 and a small-diameter tube 53 as an inserting portion 50 to a general-purpose detector 46 and a sound collector 48. Therefore, the structure is simple and the price is low. <Modification> Instead of mounting the ring 54 on the small diameter tube 53, a scale (not shown) may be formed on the outer peripheral surface. Each scale corresponds to the distance (depth) from the lower end surface 10a of the flow path forming member 10 to the position of each flow path switching valve 30. The small-diameter tube 54 with a scale inserted in the first exhaust passage 13 is pulled out until the first scale corresponds to the lower end surface 10a. Then, the tip of the small diameter tube 54 faces the first flow path switching valve 30. Therefore, the detector 4
The presence or absence of air leak in the uppermost flow passage switching valve 30 is confirmed by a meter of 6 or the like.

When there is an air leak, the flow path switching valve 30 may be immediately removed to repair the gasket, but in this case, the second flow path switching valve 30 is detected. For this purpose, the small-diameter tube 54 is pulled out until the second scale from the bottom faces the lower end surface 10a. Hereinafter, similarly, the presence or absence of air leakage in the flow path switching valve 30 is detected.

[0046]

As described above, the air leak detection method of the present invention is simple in detection work, and does not require much time and labor for detection. Further, it is possible to reduce the amount of air leakage until the air leakage is detected. On the other hand, the air leak detection tool has a simple structure and is inexpensive,
It is possible to detect air leakage in exhaust passages of various shapes.

[Brief description of drawings]

FIG. 1 is a front view of an air flow path switching device showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a front view of a sound sensing type air leak detection tool.

FIG. 4 is an explanatory diagram for explaining air leakage in a conventional air flow path switching device.

[Explanation of symbols]

10: Flow path forming member 11: Manifold 12: Air supply flow paths 13, 14: Exhaust flow path 16, 17: Output flow path 20: Pneumatic cylinder 30: Flow path switching valve 32: Air supply port 33, 34: Exhaust port 36 , 37: output port 40: valve body 45: air leak detection tool 46: detector 48: sound collector 50: insertion part 53: small diameter tube 54: ring

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Midori Yamazaki             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO F-term (reference) 2G067 AA37 BB11 BB40 CC01 DD13                       EE08                 3H066 AA04 BA38

Claims (9)

[Claims] 1. A flow path forming member having an air supply flow path connected to a compressed air source, a pair of exhaust flow paths, and a plurality of pairs of output flow paths connected to a driving device, and the flow path formation. A plurality of flow path switching valves attached to a member, each of which has an air supply port that communicates with the air supply passage, a pair of exhaust ports that communicate with a pair of the exhaust flow paths, and the output of each pair. A plurality of flow path switching devices each having a pair of output ports corresponding to the flow paths, and having a valve body for communicating the air supply port with the one output port and the other output port with the other exhaust port. A method for detecting an air leak in each of the flow path switching valves in an air flow path switching device including a valve, comprising: inserting an air leak detection tool into one of the exhaust flow paths while circulating compressed air, and then pulling it out. , Sound leakage by checking the loudness with a sound-sensing air leak detector Air leakage detection method characterized by but identifying the channel switching valve that is occurring. 2. The flow passage forming member is composed of the same number of manifolds as the flow passage switching valves, and one of the air supply passage portion forming a part of the air supply passage in each manifold and one of the exhaust passages. The detection method according to claim 1, wherein an exhaust flow passage portion that forms a portion and the output flow passage are formed. 3. The detection method according to claim 1, wherein one of the exhaust passages, into which the air leak tool is inserted, is a side from which compressed air is not discharged. 4. The detection method according to claim 1, wherein a silencer is attached to the other exhaust passage through which the compressed air is exhausted. 5. The detection method according to claim 1, wherein the air pressure of the compressed air at the time of detecting the air leak is lower than the air pressure of the compressed air at the time of operating the drive device. 6. The detection method according to claim 1, wherein a ring is attached to the air leak detection tool when air leak is confirmed when the leak detection tool is pulled out. 7. A detector, a sound collector extending from the detector, and a tubular insertion portion connected to the sound collector and having a thickness and a length that can be inserted into an exhaust passage. An air leak detection tool characterized by the above. 8. The air leakage detection tool according to claim 7, wherein the insertion portion is flexible. 9. The air leakage detection tool according to claim 7, wherein the insertion portion includes a large diameter member on the sound collector side and a small diameter member on the insertion side.