TW202042890A - Filter device - Google Patents

Abstract

A filter device is equipped with a filter portion and a particle detector. The particle detector is disposed to a supply flow path for supplying compressed air from an air supply source to a pneumatic machine and removes particles contained in the compressed air flowing in the supply flow path. The particle detector comprises: a detection flow path, an optical sensor, and a flow rate adjustment portion. The detection flow path branches from a portion of the supply flow path closer to the downstream of the flow direction of the compressed air than the filer portion and is connected to the atmosphere. The optical sensor detects the particles contained in the compressed air flowing in the detection flow path. The flow rate adjustment portion, in a manner of independent from the flow rate of the compressed air flowing in the supply flow path, adjusts the flow rate of the compressed air flowing in the detection flow path toward the optical sensor to a predetermined flow rate.

Description

filter

The invention relates to a filtering device.

For example, pneumatic equipment used in factories and the like is driven by compressed air supplied from an air supply source through a supply flow path. Generally, a filter device is provided in the supply flow path. The filter device has a filter portion (filter element) that removes particles contained in the compressed air flowing in the supply flow path before the compressed air is supplied to the pneumatic equipment. . However, as the filter is used continuously, it will gradually become clogged, reducing the ability to remove particles. In this regard, for example, the device described in Japanese Patent Application Laid-Open No. 2010-101702 can detect the difference between the pressure of compressed air before passing through the filter unit and the pressure of compressed air after passing through the filter unit. In addition, the larger the pressure difference, the more it can be determined that the filter part is clogged. In addition, the clogged filter unit is replaced with a new filter unit by the operator.

However, in the device of Japanese Patent Application Laid-Open No. 2010-101702, if the difference between the pressure of the compressed air before passing through the filter and the pressure of the compressed air after passing through the filter is not large enough, it is impossible to determine that the filter is present. The blocked state. Therefore, there is a problem that the optimal replacement timing of the filter part is not known, and the preservation cannot be prevented.

The problem to be solved by the invention An object of the present invention is to provide a filter device capable of continuously and accurately detecting particles contained in compressed air, thereby ensuring preventive maintenance of the filter unit.

Means to solve the problem In order to achieve the above-mentioned object, the filter device has a filter part which is provided in the supply flow path of the compressed air from the air supply source and the compressed air flowing in the supply flow path. The contained particles are removed. The filter device is equipped with a particle detector. The particle detector has: a detection flow path, an optical sensor, and a flow velocity adjustment part. The detection flow path diverges from a part of the supply flow path that is closer to the downstream side of the flow direction of the compressed air than the filter part, and is Connected to the atmosphere, the optical sensor detects particles contained in the compressed air flowing in the above-mentioned detection flow path, and the flow rate adjustment unit is independent of the flow rate of the compressed air flowing in the above-mentioned supply flow path. The flow velocity of the compressed air flowing toward the optical sensor in the detection flow path is adjusted to a predetermined flow velocity.

In the above-mentioned filtering device, it is preferable that the flow rate adjusting part includes: a first fixed orifice, a second fixed orifice, a branch flow path, and a release valve, and the first fixed orifice is provided in the detection flow path. The optical sensor is close to the upstream of the flow direction of the compressed air, and the second fixed orifice is provided between the first fixed orifice and the optical sensor in the detection flow path, and the area of the flow path is larger than that of the first The fixed orifice is small, the branched flow path is branched from the portion between the first fixed orifice and the second fixed orifice in the detection flow path, and is connected to the atmosphere, the release valve is provided in the branched flow path, and When the pressure of the portion between the first fixed orifice and the second fixed orifice in the detection flow path is higher than a predetermined pressure set in advance, the valve will be opened. When the release valve is opened, the first fixed orifice will be opened. The flow path area of the orifice is smaller than the flow path area of the aforementioned release valve.

In the filtering device, it is preferable that the downstream end of the flow direction of the compressed air in the branch flow path is connected to a part of the detection flow path that is closer to the downstream side of the flow direction of the compressed air than the optical sensor, and The detection flow path is connected to the atmosphere. In the detection flow path, an inspection valve is provided between the optical sensor and the downstream end of the branch flow path. The inspection valve blocks the downstream of the branch flow path. The end of the compressed air flowing into the detection flow path flows toward the optical sensor.

In the filter device, it is preferable that the flow rate adjusting part includes: a variable orifice and a variable orifice control part, and the variable orifice is provided in the detection flow path closer to the compressed air than the optical sensor On the upstream side of the flow direction, the variable orifice control unit controls the opening degree of the variable orifice according to the pressure of a portion of the supply flow path that is closer to the downstream side in the flow direction of the compressed air than the filter unit.

In the filtering device, it is preferable that the particle detector further includes a solenoid valve and a solenoid valve control unit, and the solenoid valve is provided at an end of the detection flow path adjacent to the supply flow path, and the solenoid valve control unit controls For opening and closing of the solenoid valve, the solenoid valve control unit opens the solenoid valve with a predetermined frequency set in advance.

In the filtering device, it is preferable that the solenoid valve control unit closes the solenoid valve when the amount of particles detected by the optical sensor exceeds a predetermined amount set in advance.

In the filter device, it is preferable that the detection flow path is provided with a diffusion member that diffuses the compressed air flowing in the detection flow path.

In the above-mentioned filtering device, it is preferable that the particle detector is attached to the main body in a state of being arranged outside the main body that houses the filtering unit.

Invention effect According to this invention, the particles contained in the compressed air can be continuously and accurately detected, and the filter unit can be reliably prevented and maintained.

Hereinafter, the first embodiment of the actualized filter device will be described based on FIG. 1.

As shown in FIG. 1, the filter device 10 is provided in a supply flow path 13 that supplies compressed air from an air supply source 11 to the air compressor 12. The air compressor 12 is driven by compressed air supplied from the air supply source 11 through the supply flow path 13. The supply flow path 13 is constituted by, for example, a pipe or the like.

The filter device 10 has a main body 14. The main body 14 has a supply hole 14a and a discharge hole 14b. The supply flow path 13 has a first flow path 13a, a second flow path 13b, and a third flow path 13c. The first flow path 13 a connects the air supply source 11 and the supply hole 14 a outside the main body 14. The second flow path 13 b connects the supply hole 14 a and the discharge hole 14 b inside the main body 14. The third flow path 13c connects the discharge hole 14b and the pneumatic device 12 outside the main body 14.

The filter device 10 has a filter unit 15. The filter 15 is housed in the main body 14. The filter unit 15 is provided in the second flow path 13 b of the supply flow path 13. The filter portion 15 is, for example, a cylindrical filter element. Before the compressed air is supplied to the air compressor 12, the filter unit 15 removes particles contained in the compressed air flowing in the second flow path 13b in the supply flow path 13. The filter unit 15 captures particles contained in the compressed air passing through the filter unit 15.

The filter device 10 includes a particle detector 20. In this embodiment, the particle detector 20 is built in the main body 14 of the filter device 10. The particle detector 20 has a detection flow path 21. The detection flow path 21 is constituted by a pipe or the like, for example. The detection flow path 21 is branched from a portion of the second flow path 13b of the supply flow path 13 that is closer to the downstream side in the flow direction of the compressed air than the filter section 15 and is connected to the atmosphere. Therefore, one end of the detection flow path 21 is connected to the second flow path 13b of the supply flow path 13, and the other end of the detection flow path 21 is opened to the atmosphere.

The particle detector 20 has an optical sensor 22. The optical sensor 22 detects particles contained in the compressed air flowing in the detection flow path 21. The optical sensor 22 has a light emitting and receiving portion 22a. The light emitting and receiving unit 22a is provided in the detection flow path 21. The light projecting and receiving unit 22a has a light projecting unit and a light receiving unit not shown. In addition, the light projecting and receiving unit 22a is configured such that the light emitted from the light projecting unit irradiates the compressed air flowing in the detection flow path 21, and at the same time irradiates the light reflected by the particles contained in the compressed air, that is, scattered The light is received by the light receiving part.

The optical sensor 22 detects the particles contained in the compressed air flowing in the detection flow path 21 based on the light intensity level of the light received by the light receiving unit in the light projecting and receiving unit 22a. For example, the optical sensor 22 has a controller 23, and an electronic signal according to the light intensity level of the light received by the light receiving unit is transmitted from the light receiving unit to the controller 23. The controller 23 detects the particle size and number of particles based on the signal intensity of the electronic signal transmitted from the light receiving unit.

The controller 23 is electrically connected to an external control device 24 such as a programmable logic controller (PLC). In addition, when the particle size detected by the controller 23 is larger than the preset particle size, or when the amount of the particles detected by the controller 23 exceeds the preset amount, the controller 23 will notify the operation Signals related to the need for replacement of the filter unit 15 are sent to the external control device 24.

The external control device 24 is configured to, when receiving a signal for notifying the operator of the need to replace the filter unit 15 with related information, it will notify the operator that the filter unit 15 needs to be replaced. The external control device 24 has, for example, a display to indicate that it is necessary to replace the filter unit 15 to the operator.

The particle detector 20 has a first fixed orifice 25, a second fixed orifice 26, a branch flow path 27, and a release valve 28. The first fixed flow hole 25 is provided in the detection flow path 21 on the upstream side in the flow direction of the compressed air from the light projecting and receiving portion 22 a of the optical sensor 22. The second fixed orifice 26 is provided between the first fixed orifice 25 in the detection flow path 21 and the light projecting and receiving portion 22 a of the optical sensor 22. The flow path area of the second fixed orifice 26 is smaller than the flow path area of the first fixed orifice 25.

The branch flow path 27 is branched from a portion between the first fixed orifice 25 and the second fixed orifice 26 in the detection flow path 21. The branch flow path 27 is constituted by, for example, piping. The downstream end in the flow direction of the compressed air in the branch flow path 27 is connected to a part of the detection flow path 21 that is closer to the downstream side in the flow direction of the compressed air than the light projecting and receiving portion 22 a of the optical sensor 22. Therefore, the branch flow path 27 is connected to the atmosphere via the detection flow path 21.

The release valve 28 is provided in the branch flow path 27. The relief valve 28 is configured to open when the pressure of the portion between the first fixed orifice 25 and the second fixed orifice 26 in the detection flow path 21 is higher than a predetermined pressure set in advance. The relief valve 28 is configured such that the flow path area when the valve is opened is larger than the flow path area of the first fixed orifice 25. Therefore, the flow path area of the first fixed orifice 25 is smaller than the flow path area of the release valve 28 when the release valve 28 is opened.

In the detection flow path 21, an inspection valve 29 is provided between the light projecting and receiving portion 22 a of the optical sensor 22 and the connection portion connected to the downstream end of the branch flow path 27. The inspection valve 29 blocks the flow of compressed air flowing into the detection flow path 21 from the downstream end of the branch flow path 27 toward the light projecting and receiving portion 22 a of the optical sensor 22.

The particle detector 20 further has a solenoid valve 30. The solenoid valve 30 is provided at the end of the detection flow path 21 adjacent to the supply flow path 13. The solenoid valve 30 is provided between the first fixed orifice 25 and the connecting portion of the detection flow path 21 and the supply flow path 13. The solenoid valve 30 is electrically connected to the controller 23. The controller 23 has previously memorized a program that commands the solenoid valve 30 to open when receiving a command signal from the external control device 24 to command the solenoid valve 30 to open.

The controller 23 receives a command signal from the external control device 24 instructing the solenoid valve 30 to open, for example, by the operator pressing an execution button provided in the external control device 24. The timing at which the operator presses the execution button of the external control device 24 is predetermined in the operator's work procedure. Therefore, in this embodiment, the controller 23 opens the solenoid valve 30 at a predetermined frequency set in advance.

The controller 23 has a timer function. The controller 23 has previously memorized a program that starts time measurement while opening the solenoid valve 30, and orders the solenoid valve 30 to close after a predetermined time has elapsed. Therefore, the controller 23 opens the solenoid valve 30 only during a predetermined period set in advance. In addition, the controller 23 has a program stored in advance: when the amount of particles detected by the controller 23 exceeds a predetermined amount set in advance, the solenoid valve 30 is commanded to close. Therefore, the controller 23 has a function of a solenoid valve control unit that controls the opening and closing of the solenoid valve 30.

The detection flow path 21 is provided with a diffusion member 31. The diffusion member 31 is provided between the second fixed orifice 26 in the detection flow path 21 and the light projecting and receiving portion 22 a of the optical sensor 22. The diffusion member 31 is, for example, a thin-plate porous metal plate in which a plurality of holes are formed. Inside the pipe constituting the detection flow path 21, the diffusion member 31 is arranged such that the plate thickness direction of the diffusion member 31 coincides with the axial direction of the pipe. In addition, the compressed air flowing in the detection flow path 21 is diffused by passing through the plurality of holes of the diffusion member 31. Therefore, the diffusion member 31 diffuses the compressed air flowing in the detection flow path 21.

The end of the detection channel 21 on the opposite side of the supply channel 13 protrudes from the main body 14. A muffler 32 is provided in a portion of the detection flow path 21 protruding from the main body 14. Therefore, the silencer 32 is provided at the end of the detection flow path 21 on the opposite side of the supply flow path 13. The silencer 32 can suppress the exhaust sound of compressed air when the compressed air is discharged from the detection flow path 21 to the atmosphere. In addition, a filter 33 is provided at the end of the detection flow path 21 on the opposite side of the supply flow path 13. The filter 33 removes particles contained in the compressed air passing through the detection flow path 21. The filter 33 captures particles contained in the compressed air passing through the filter 33.

Next, the effect of this embodiment will be described.

The compressed air supplied from the air supply source 11 to the supply flow path 13 passes through the filter 15 while flowing in the supply flow path 13. The filter unit 15 removes particles contained in the compressed air passing through the filter unit 15. In addition, the compressed air from which particles have been removed by the filter portion 15 is supplied to the air compressor 12 through the supply flow path 13.

When the operator presses the execution button of the external control device 24, a command signal for opening the solenoid valve 30 is transmitted from the external control device 24 to the controller 23, and the controller 23 receives the command signal from the external control device 24. The solenoid valve 30 is opened. In addition, the controller 23 starts time measurement while opening the solenoid valve 30.

The detection flow path 21 is branched from a portion of the second flow path 13b of the supply flow path 13 that is closer to the downstream side in the flow direction of the compressed air than the filter section 15 and is connected to the atmosphere. Therefore, when the solenoid valve 30 is opened, a part of the compressed air flowing in the supply flow path 13 continues to flow into the detection flow path 21. Therefore, the detection flow path 21 continuously generates a flow of compressed air from the supply flow path 13.

The compressed air flowing from the supply channel 13 into the detection channel 21 passes through the solenoid valve 30 and the first fixed orifice 25, and then flows into the detection channel 21 between the first fixed orifice 25 and the second fixed orifice 26. At this time, the flow path area of the second fixed orifice 26 is smaller than the flow path area of the first fixed orifice 25. When the pressure of the portion between the first fixed orifice 25 and the second fixed orifice 26 in the detection flow path 21 is higher than a predetermined pressure set in advance, the release valve 28 opens.

Therefore, for example, when the pressure of the portion between the first fixed orifice 25 and the second fixed orifice 26 in the detection flow path 21 is higher than a predetermined pressure set in advance, the first fixed orifice 25 and the second fixed flow Part of the compressed air flowing into the branch flow path 27 between the holes 26 passes through the release valve 28. Then, the compressed air passing through the release valve 28 passes through the branch flow path 27, passes through the downstream end of the branch flow path 27, and flows into the detection flow path 21 which is closer to the flow direction of the compressed air than the light emitting and receiving portion 22a of the optical sensor 22. The downstream part is then discharged to the atmosphere through the detection flow path 21. Among them, the flow of compressed air flowing from the downstream end of the branch flow path 27 into the detection flow path 21 toward the light projecting and receiving portion 22 a of the optical sensor 22 is blocked by the inspection valve 29.

In addition, by setting the flow path area of the first fixed orifice 25 to be smaller than the flow path area of the release valve 28 when the release valve 28 is opened, the detection of the first fixed orifice 25 and the second fixed orifice in the flow path 21 The pressure of the portion between 26 is maintained at a predetermined pressure lower than the pressure of the supply flow path 13. Thereby, the flow velocity of the compressed air flowing into the light projecting and receiving portion 22a of the optical sensor 22 through the second fixed orifice 26 is adjusted to a predetermined flow velocity regardless of the flow velocity of the compressed air flowing in the supply flow path 13.

Therefore, the first fixed orifice 25, the second fixed orifice 26, the branch flow path 27, and the release valve 28 constitute a flow rate adjustment unit 35 that is independent of the flow rate of the compressed air flowing in the supply flow path 13. In the method, the flow rate of the compressed air flowing toward the optical sensor 22 in the detection flow path 21 is adjusted to a predetermined flow rate. Therefore, the flow velocity adjusting unit 35 of the present embodiment includes a first fixed orifice 25, a second fixed orifice 26, a branch flow path 27, and a relief valve 28.

The compressed air passing through the second fixed flow hole 26 passes through the diffusion member 31 and is diffused before flowing into the light projecting and receiving portion 22 a of the optical sensor 22. In this way, the flow velocity of the compressed air flowing between the diffusing member 31 and the light emitting and receiving portion 22a of the optical sensor 22 in the pipe constituting the detection flow path 21 is uniformized.

The optical sensor 22 detects particles contained in the compressed air passing through the diffusion member 31 in the detection flow path 21. Specifically, the light emitted from the light projecting section of the light projecting and receiving section 22a is irradiated on the compressed air flowing in the detection flow path 21, and at the same time, the compressed air is irradiated with light reflected by the particles contained in the compressed air, that is, scattered The light is received by the light receiving part. At this time, the flow rate of the compressed air flowing in the detection flow path 21 is adjusted to a predetermined flow rate regardless of the flow rate of the compressed air flowing in the supply flow path 13, and the flow rate of the compressed air is adjusted by the diffuser 31 Homogenize in the piping. Therefore, the light emitted from the light projecting part is accurately reflected by the particles, and the scattered light reflected by the particles is accurately received by the light receiving part.

Then, an electronic signal according to the light intensity level of the light received by the light receiving unit is transmitted from the light receiving unit to the controller 23. The controller 23 detects the particle size and number of particles based on the signal intensity of the electronic signal transmitted from the light receiving unit.

When the particle size detected by the controller 23 is less than the preset particle size, and the amount of the particles detected by the controller 23 is less than the preset predetermined amount, if the timer has measured After a predetermined time, the controller 23 closes the solenoid valve 30.

On the other hand, when the particle size detected by the controller 23 is larger than the preset particle size, or the amount of the particles detected by the controller 23 exceeds the preset amount, the controller 23 will report the relevant information The signal of is sent to the external control machine 24 to inform the operator that the filter unit 15 needs to be replaced. Then, the controller 23 closes the solenoid valve 30.

When receiving a signal from the controller 23 to inform the operator that the filter 15 needs to be replaced, the external control device 24 will display it on the display to inform the operator that the filter 15 needs to be replaced.

The above-mentioned embodiment can obtain the following effects.

(1) As mentioned in the background art, in the device of Japanese Patent Application Laid-Open No. 2010-101702, there is a problem that the optimal replacement time of the filter part is not known, and the maintenance cannot be prevented.

In this regard, the particles contained in the compressed air flowing in the supply flow path through the filter section are detected using, for example, an optical sensor. In this way, with a device like Japanese Patent Application Publication No. 2010-101702, the difference between the pressure of the compressed air before passing through the filter and the pressure of the compressed air after passing through the filter is detected to determine the clogging state of the filter Compared with the situation, it is possible to accurately determine the clogging state of the filter unit, and perform preventive maintenance of the filter unit.

However, even if the optical sensor is used, if the flow of compressed air is not generated in the supply flow path, the particles contained in the compressed air cannot be detected. Therefore, it is not possible to continuously detect the particles contained in the compressed air without an optical sensor. Furthermore, the flow rate of the compressed air flowing in the supply flow path depends on the use state of the pneumatic equipment. Therefore, when the flow rate of the compressed air flowing in the supply flow path is too fast, it will be difficult to accurately detect the particles contained in the compressed air by the optical sensor, so it is impossible to accurately determine the clogging state of the filter. There is a possibility that preventive maintenance of the filter part cannot be reliably performed.

According to this embodiment, the detection flow path 21 is branched from the portion of the supply flow path 13 on the downstream side of the filter portion 15 in the flow direction of the compressed air, and is connected to the atmosphere. The particle detector 20 has an optical sensor 22 that detects particles contained in the compressed air flowing in the detection flow path 21 and a flow velocity adjustment unit 35, and the flow velocity adjustment unit 35 does not The method of supplying the flow rate of the compressed air flowing in the flow path 13 adjusts the flow rate of the compressed air flowing toward the optical sensor 22 in the detection flow path 21 to a predetermined flow rate.

According to this configuration, since the detection flow path 21 is connected to the atmosphere, the flow of compressed air from the supply flow path 13 is continuously generated in the detection flow path 21, so the optical sensor 22 can continuously detect the flow in the detection flow path 21 Particles contained in flowing compressed air. In addition, since the flow velocity adjusting unit 35 adjusts the flow velocity of the compressed air flowing toward the optical sensor 22 in the detection flow path 21 to a predetermined flow velocity irrespective of the flow velocity of the compressed air flowing in the supply flow path 13 Therefore, the particles contained in the compressed air flowing in the detection flow path 21 can be accurately detected. Therefore, the clogging state of the filter unit 15 can be accurately determined. As described above, the particles contained in the compressed air can be continuously and accurately detected, and the preventive maintenance of the filter unit 15 can be performed reliably.

(2) The flow velocity adjusting unit 35 includes the first fixed orifice 25, the second fixed orifice 26, the branch flow path 27, and the relief valve 28. In this way, when the pressure of the portion between the first fixed orifice 25 and the second fixed orifice 26 in the detection flow path 21 is higher than a predetermined pressure set in advance, the release valve 28 opens. In addition, part of the compressed air flowing into the branch flow path 27 from the portion between the first fixed flow hole 25 and the second fixed flow hole 26 is discharged to the atmosphere through the release valve 28. When the release valve 28 is opened, the flow path area of the first fixed orifice 25 is smaller than the flow path area of the release valve 28.

In this way, the pressure of the portion between the first fixed orifice 25 and the second fixed orifice 26 in the detection flow path 21 can be maintained below a predetermined pressure lower than the pressure of the supply flow path 13, regardless of The method of supplying the flow velocity of the compressed air flowing in the flow path 13 adjusts the flow velocity of the compressed air flowing toward the optical sensor 22 through the second fixed orifice 26 to a predetermined flow velocity. Therefore, since the flow rate of the compressed air flowing in the detection flow path 21 toward the optical sensor 22 is adjusted to a predetermined flow rate regardless of the flow rate of the compressed air flowing in the supply flow path 13, it can be mechanically changed. It is not controlled electronically.

(3) The downstream end of the compressed air flow direction in the branch flow path 27 is connected to the downstream side of the detection flow path 21 closer to the optical sensor 22 in the flow direction of the compressed air, and is connected to the atmosphere through the detection flow path 21 . Furthermore, in the detection flow path 21, a check valve 29 is provided between the optical sensor 22 and the connection part connected to the downstream end of the branch flow path 27. The check valve 29 blocks the flow into the detection flow path from the downstream end of the branch flow path 27. The compressed air 21 flows toward the optical sensor 22. In this way, since the compressed air flowing into the branch flow path 27 can be concentrated in the detection flow path 21 and discharged to the atmosphere, the flow path structure of the particle detector 20 can be simplified.

(4) The particle detector 20 further includes the solenoid valve 30 provided at the end of the detection flow path 21 adjacent to the supply flow path 13. The controller 23 controls the opening and closing of the solenoid valve 30. In addition, the controller 23 opens the solenoid valve 30 using a predetermined frequency set in advance. In this way, only when the solenoid valve 30 is opened, the flow of compressed air from the supply flow path 13 can be continuously generated in the detection flow path 21. Therefore, even when there is no need to detect the particles contained in the compressed air, since part of the compressed air flowing in the supply flow path 13 does not flow into the detection flow path 21, the compressed air can be efficiently supplied to the air pressure. Machine 12.

(5) When the amount of particles detected by the optical sensor 22 exceeds a predetermined amount, the controller 23 closes the solenoid valve 30. In this way, it is possible to prevent a part of the compressed air flowing in the supply flow path 13 from passing through the detection flow path 21 and being discharged to the atmosphere. Therefore, it is possible to prevent the compressed air from passing through the detection flow path 21 and being discharged to the atmosphere when the compressed air contains too many particles.

(6) The detection flow path 21 is provided with the diffusion member 31 which diffuses the compressed air flowing in the detection flow path 21. In this way, the compressed air is diffused by the diffusion member 31, and the flow velocity of the compressed air flowing in the detection flow path 21 is uniformized. Therefore, the optical sensor 22 can further accurately detect the particles contained in the compressed air flowing in the detection flow path 21.

(7) A silencer 32 is provided at the end of the detection flow path 21 on the opposite side of the supply flow path 13. In this way, it is possible to suppress the exhaust noise of the compressed air when the compressed air is discharged from the detection flow path 21 to the atmosphere.

(8) The filter 33 is provided at the end of the detection flow path 21 on the opposite side of the supply flow path 13. In this way, since the filter 33 captures particles contained in the compressed air passing through the filter 33, it is possible to suppress the problem of particles scattering into the atmosphere when the compressed air is discharged from the detection flow path 21 to the atmosphere.

(9) The pressure of the portion between the first fixed orifice 25 and the second fixed orifice 26 in the detection flow path 21 is maintained at a predetermined pressure lower than the pressure of the supply flow path 13. In this way, since the pressure of the compressed air flowing toward the optical sensor 22 in the detection flow path 21 is suppressed and does not exceed the bearing pressure of the optical sensor 22, the durability of the optical sensor 22 can be improved.

However, the above-mentioned embodiment can also be modified and implemented as follows. The above-mentioned embodiment and the following modified examples can be implemented in combination with each other as long as they are not technically contradictory.

・As shown in FIG. 2, the particle detector 20 may not have the first fixed orifice 25, the second fixed orifice 26, the branch flow path 27, and the release valve 28, but a variable orifice 41. The variable flow hole 41 is arranged on the upstream side of the detection flow path 21 closer to the flow direction of the compressed air than the light projecting and receiving portion 22 a of the optical sensor 22.

The variable orifice 41 is electrically connected to the controller 23. In addition, the particle detector 20 has a pressure sensor 42 that detects the pressure of a portion of the supply flow path 13 that is closer to the downstream side than the filter portion 15 in the flow direction of the compressed air. The pressure sensor 42 is electrically connected to the controller 23. The pressure information detected by the pressure sensor 42 is sent to the controller 23. The controller 23 has previously memorized a program for controlling the opening degree of the variable orifice 41 according to the pressure information transmitted from the pressure sensor 42. Therefore, the controller 23 has the function of a variable orifice control unit, and controls the opening degree of the variable orifice 41 in accordance with the pressure of the portion of the supply flow path 13 on the downstream side of the filter unit 15 in the flow direction of the compressed air.

Thereby, regardless of the flow rate of the compressed air flowing in the supply flow path 13, the flow rate of the compressed air flowing in the detection flow path 21 through the variable orifice 41 and flowing toward the optical sensor 22 is adjusted to a predetermined value. The flow rate. Therefore, the variable orifice 41, the pressure sensor 42, and the controller 23 constitute a flow rate adjustment unit 45 that detects the flow rate regardless of the flow rate of the compressed air flowing in the supply flow path 13 The flow rate of the compressed air flowing toward the optical sensor 22 in the path 21 is adjusted to a predetermined flow rate. Therefore, the flow rate adjusting unit 45 of the embodiment shown in FIG. 2 includes the variable orifice 41 and the controller 23.

The controller 23 controls the opening degree of the variable orifice 41 according to the pressure of the portion of the supply flow path 13 on the downstream side of the filter portion 15 in the flow direction of the compressed air, thereby making the detection flow path 21 face the optical sensing The flow rate of the compressed air flowing through the device 22 is adjusted. In this way, the flow rate of the compressed air flowing in the detection flow channel 21 toward the optical sensor 22 can be accurately adjusted to a predetermined flow rate regardless of the flow rate of the compressed air flowing in the supply flow channel 13. Among them, in the case of the embodiment shown in FIG. 2, the optical sensor 22 must be configured to be able to withstand the pressure of the compressed air flowing toward the optical sensor 22 in the detection flow path 21. For example, the light projecting and receiving unit 22a of the optical sensor 22 can also be arranged outside the pipe that constitutes the detection flow path 21.

・In the embodiment, the downstream end in the flow direction of the compressed air in the branch flow path 27 can also be connected to the detection flow path 21 separately from the atmosphere, instead of being connected to the detection flow path 21 closer to the compressed air than the optical sensor 22 The parts on the downstream side in the flow direction are connected. At this time, the silencer 32 and the filter 33 can also be provided at the downstream end of the branch flow path 27 in the same manner as the detection flow path 21.

・In the embodiment, the following configuration is also possible: the inspection valve 29 is not provided between the optical sensor 22 in the detection flow path 21 and the connection part connected to the downstream end of the branch flow path 27, and the check valve 29 blocks the branch from the The downstream end of the flow path 27 detects the flow of compressed air in the flow path 21 toward the optical sensor 22.

・In the embodiment, the controller 23 receives the command signal from the external control device 24 instructing the solenoid valve 30 to open, for example, by the operator pressing the execution button provided in the external control device 24, but it is not limited to this . For example, a command signal for instructing the solenoid valve 30 to open can also be automatically transmitted from the external control device 24 to the controller 23 at a predetermined timing.

-In the embodiment, even when the amount of particles detected by the optical sensor 22 exceeds a predetermined amount set in advance, the controller 23 can not close the solenoid valve 30.

-In the embodiment, for example, a part of the gap of the solenoid valve 30 can function as the first fixed orifice 25. In this way, it is not necessary to additionally add the first fixed orifice 25 to the detection flow path 21 in addition to the solenoid valve 30, and the structure can be simplified.

・In the embodiment, the particle detector 20 can also be configured without the solenoid valve 30.

・In the embodiment, the diffusion member 31 may be a thin-plate-shaped metal mesh, for example.

-In the embodiment, the detection flow path 21 may not be provided with the diffusion member 31 that diffuses the compressed air flowing in the detection flow path 21.

-In the embodiment, the silencer 32 may not be provided at the end of the detection flow path 21 on the opposite side of the supply flow path 13.

・In the embodiment, the filter 33 may not be provided at the end of the detection flow path 21 on the opposite side of the supply flow path 13.

・As shown in FIG. 3, the particle detector 20 may not be built in the inside of the main body 14 of the filter device 10, but may be arranged side by side with the main body 14 of the filter device 10, for example. At this time, the particle detector 20 is arranged between the main body 14 of the filter device 10 and the air compressor 12, and a part of the supply flow path 13 on the downstream side of the filter portion 15 in the flow direction of the compressed air penetrates the particle detector 20. internal. The particle detector 20 is attached to the main body 14 in a state of being arranged outside the main body 14. In this way, the particle detector 20 can be easily modified relative to the main body 14. In addition, since the particle detector 20 can also be easily detached from the main body 14, maintenance can be easily performed.

・In the embodiment, the optical sensor 22 can also be configured as follows: For example, the light emitted by the light projecting unit is received by the light receiving unit, and the light emitted by the light projecting unit is shielded by particles contained in the compressed air. As a result, the light intensity level of the light received by the light receiving unit changes.

・In the embodiment, the external control device 24 can also be configured as follows: when a signal is received from the controller 23 to inform the operator that there is a need to replace the filter unit 15 with information, for example, it can be flashed or buzzed The sound informs the operator that the filter unit 15 needs to be replaced.

10: Filter device 11: Air supply source 12: Air pressure machine 13: Supply flow path 14: main body 15: Filter section 20: particle detector 21: Detection flow 22: Optical sensor 22a: Light emitting and receiving part 23: Controller, which functions as a solenoid valve control unit or a variable orifice control unit 24: External control machine 25: 1st fixed orifice 26: 2nd fixed orifice 27: Bifurcation 28: release valve 29: check valve 30: Solenoid valve 31: Diffusion member 32: silencer 33: filter 35: Flow rate adjustment part 41: Variable orifice 45: Flow rate adjustment part

Fig. 1 is a diagram for explaining the filtration device of the first embodiment. Fig. 2 is a diagram for explaining the filtration device of the second embodiment. Fig. 3 is a diagram for explaining the filtering device of the third embodiment.

10: Filter device

11: Air supply source

12: Air pressure machine

13: Supply flow path

14: main body

15: Filter section

20: particle detector

21: Detection flow

22: Optical sensor

22a: Light emitting and receiving part

23: Controller

24: External control machine

25: 1st fixed orifice

26: 2nd fixed orifice

27: Bifurcation

28: release valve

29: check valve

30: Solenoid valve

31: Diffusion member

32: silencer

33: filter

35: Flow rate adjustment part

Claims (8)

A filter device having a filter portion provided in a supply flow path that supplies compressed air from an air supply source to an air compressor, and removes particles contained in the compressed air flowing in the supply flow path , The filtering device is equipped with a particle detector, The particle detector has: a detection flow path, an optical sensor, and a flow rate adjustment part, The detection flow path is branched from a part of the supply flow path that is closer to the downstream side in the flow direction of the compressed air than the filter part, and is connected to the atmosphere, The optical sensor detects particles contained in the compressed air flowing in the detection flow path, The flow velocity adjustment unit adjusts the flow velocity of the compressed air flowing toward the optical sensor in the detection flow path to a predetermined flow velocity regardless of the flow velocity of the compressed air flowing in the supply flow path. The filtering device according to claim 1, wherein: The above-mentioned flow rate adjusting part includes: a first fixed orifice, a second fixed orifice, a branch flow path, and a release valve, The first fixed orifice is provided in the detection flow path, which is closer to the upstream of the flow direction of the compressed air than the optical sensor, and The second fixed orifice is provided between the first fixed orifice and the optical sensor in the detection flow path, and the area of the flow path is smaller than that of the first fixed orifice, The branch flow path is branched from the part between the first fixed orifice and the second fixed orifice in the detection flow path, and is connected to the atmosphere, The relief valve is provided in the branch flow path and opens when the pressure in the portion between the first fixed orifice and the second fixed orifice in the detection flow path is higher than a predetermined pressure set in advance, The flow path area of the first fixed orifice is smaller than the flow path area of the release valve when the release valve is opened. The filtering device according to claim 2, wherein: The downstream end in the flow direction of the compressed air in the branch flow path is connected to a part of the detection flow path that is closer to the downstream side in the flow direction of the compressed air than the optical sensor, and is connected to the atmosphere through the detection flow path, In the detection flow path, a check valve is provided between the optical sensor and the connection portion connected to the downstream end of the branch flow path, and the check valve blocks the flow of water from the downstream end of the branch flow path into the detection flow path. The flow of compressed air toward the optical sensor. The filtering device according to claim 1, wherein: The above-mentioned flow rate adjustment unit includes: a variable orifice and a variable orifice control unit, The variable orifice is arranged on the upstream side of the detection flow path closer to the flow direction of the compressed air than the optical sensor, The variable orifice control unit controls the opening degree of the variable orifice in accordance with the pressure of a part of the supply flow path that is closer to the downstream side in the flow direction of the compressed air than the filter unit. The filtering device according to any one of claims 1 to 4, wherein: The above-mentioned particle detector further has: a solenoid valve and a solenoid valve control unit, The solenoid valve is provided at an end of the detection flow path adjacent to the supply flow path, The solenoid valve control unit controls the opening and closing of the solenoid valve, The solenoid valve control unit opens the solenoid valve using a predetermined frequency set in advance. The filtering device according to claim 5, wherein: When the amount of particles detected by the optical sensor exceeds a predetermined amount set in advance, the solenoid valve control unit closes the solenoid valve. The filtering device according to any one of claims 1 to 4, wherein: The detection flow path is provided with a diffusion member that diffuses the compressed air flowing in the detection flow path. The filtering device according to any one of claims 1 to 4, wherein: The said particle detector is attached to the said main body in the state arrange|positioned outside the main body which accommodates the said filter part.

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