JP2009236000A - Air compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air compressor enabling cleaning of an inlet filter while restraining decline of the energy efficiency. <P>SOLUTION: Provided is a bypass path 39 for connecting an intake path 28 for guiding the external air to an intake port 12 of a compressor main body 14 via an inlet filter 29 and an outlet path 31 for guiding compressed air from an ejection port 13 of the compressor main body 14 to the outside. A channel switching valve 40 is provided at a connecting position of the outlet path 31 and the bypass path 39 so that the compressed air remaining in the outlet path 31 is supplied to the bypass path 39 by the channel switching valve 40 at the time of stoppage of the compressor main body 14. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an air compressor.

The air compressor has a compressor body that compresses air sucked from the suction port and discharges it from the discharge port, a suction passage that guides outside air to the suction port through a suction filter, and compressed air from the discharge port to the air tank Some have a leading passage. In such an air compressor, in order to prevent clogging of the suction filter, there is a type in which the compressed air in the air tank is caused to flow backward through the suction filter by switching the flow path switching valve (see, for example, Patent Document 1). .
Japanese Patent Laid-Open No. 7-139477

  In the above air compressor, there is a problem in that energy efficiency is poor because the compressed air generated by the operation of the compressor body and stored in the air tank flows into the suction filter to clean the suction filter.

  Therefore, an object of this invention is to provide the air compressor which can wash | clean a suction filter, suppressing the fall of energy efficiency.

  In order to achieve the above object, the present invention connects a suction passage that guides outside air to a suction port of a compressor body through a suction filter and a lead-out passage that guides compressed air from a discharge port of the compressor body to the outside. A flow path switching valve is provided at a connection position between the bypass passage and the outlet passage and the bypass passage, and the flow path switching valve guides compressed air from the discharge port to the outside through the outlet passage when the compressor body is in operation. When the compressor main body is stopped, the compressed air in the outlet passage is switched to flow through the bypass passage.

  According to the present invention, when the compressed air in the outlet passage is caused to flow through the bypass passage by the flow path switching valve when the compressor body is stopped, the suction filter can be washed with the compressed air remaining in the outlet passage. Therefore, it is possible to clean the suction filter while suppressing a decrease in energy efficiency.

“First Embodiment”
An air compressor according to a first embodiment of the present invention will be described below with reference to FIGS.
The air compressor 11 according to the first embodiment includes a compressor body 14 that compresses air sucked from the suction port 12 and discharges it from the discharge port 13.

  The compressor body 14 is of a scroll type, and has a covered cylindrical casing 18 having a bearing portion 17, a drive shaft 20 that is rotatably provided on the bearing portion 17 of the casing 18 with a tip 19 serving as a crank 19, The orbiting scroll 22 rotatably supported by the crank 19 of the drive shaft 20 and the orbiting scroll 22 provided integrally with the opening end side of the casing 18 are arranged opposite to the orbiting scroll 22. 23 and a fixed scroll 24 that defines 23.

  The fixed scroll 24 is provided with the suction port 12 described above so as to open to the compression chamber 23 on the outer peripheral side, and the discharge port 13 described above so as to open to the compression chamber 23 on the center side.

  The compressor body 14 is driven by a motor (not shown) to rotate, and the orbiting scroll 22 makes an orbiting motion. As a result, the air sucked from the suction port 12 is absorbed by the fixed scroll 24 and the compressor body 14. Compressed in each compression chamber 23 formed between the orbiting scrolls 22 and discharged from the discharge port 13.

  The air compressor 11 includes a suction passage 28 connected to the suction port 12 of the compressor body 14, and a suction filter 29 that is provided at an end of the suction passage 28 opposite to the compressor body 14 and captures dust from outside air. The suction passage 28 guides the outside air taken in via the suction filter 29 to the suction port 12.

  In addition, the air compressor 11 is provided in a lead-out passage 31 connected to the discharge port 13 of the compressor main body 14 and an external air that is provided at the end of the lead-out passage 31 opposite to the compressor main body 14 and stores air. A check valve 33 which is disposed in the vicinity of the discharge port 13 in the outlet passage 31 to prevent the backflow of air to the compressor body 14 side, the check valve 33 in the outlet passage 31 and the air tank 32; And an aftercooler 34 that cools the high-temperature air in the outlet passage 31, and the outlet passage 31 sends compressed air from the discharge port 13 to the air tank via the check valve 33 and the aftercooler 34. Lead to 32. A fan 36 that blows cooling air to the aftercooler 34 is connected to the drive shaft 20 via a belt 37.

  The air compressor 11 of the first embodiment is provided with a bypass passage 39 that connects a position between the aftercooler 34 of the outlet passage 31 and the air tank 32 and the suction passage 28. A flow path switching valve 40 is provided at a connection position with the passage 39.

  The flow path switching valve 40 is a two-position three-way valve, and is energized to close the bypass passage 39 and communicate the compressor body 14 and the air tank 32 with the outlet passage 31 as shown in FIG. 1, the air tank 32 side of the outlet passage 31 is closed and the compressor body 14 side of the outlet passage 31 is connected to the bypass passage 39 as shown in FIG. That is, the flow path switching valve 40 switches between the A position for guiding the compressed air from the discharge port 13 to the air tank 32 via the outlet passage 31 and the B position for allowing the compressed air in the outlet passage 31 to flow to the bypass passage 39. It is done.

  Then, the control device (not shown) of the air compressor 11 drives the motor and operates the compressor main body 14 to excite the flow path switching valve 40 to the A position, as shown in FIG. 39 is closed, and the compressor main body 14 and the air tank 32 are brought into communication with each other through the outlet passage 31. Then, the compressor main body 14 sucks air from the suction port 12 through the suction filter 29 and the suction passage 28, compresses it in the compression chamber 23, and guides it from the discharge port 13 to the air tank 32 through the lead-out passage 31.

  Further, when the control device stops the compressor main body 14 by stopping the motor, the flow switching valve 40 is demagnetized at the same time as the B position, and the air tank 32 side of the outlet passage 31 is set to the B position as shown in FIG. The compressor body 14 side of the outlet passage 31 and the bypass passage 39 are connected. Then, the compressed air remaining between the compressor body 14 and the flow path switching valve 40 in the outlet passage 31 and in the aftercooler 34 flows to the suction filter 29 via the bypass passage 39 and is discharged from the suction filter 29. At this time, the exhaust removes the dust trapped in the suction filter 29 and releases it to the outside air (so-called backwashing).

  For example, as shown in FIG. 3, the control device turns on the flow path switching valve 40 at the timing t <b> 1 at which the operation of the compressor main body 14 is started to set the A position, and the compressed air from the discharge port 13 of the compressor main body 14. Is led to the air tank 32 through the lead-out passage 31, and at the timing t2 when the compressor body 14 is continuously operated for a preset time TT, the compressor body 14 is stopped and the flow path switching valve 40 is turned on. Turn OFF and switch to B position. As a result, the compressed air remaining in the outlet passage 31 and the aftercooler 34 is discharged from the suction filter 29 to clean the suction filter 29.

  Then, at a timing t3 when a preset time TB has elapsed from the timing t2, the flow path switching valve 40 is turned on again to switch to the A position, and then compressed from the timing t2 to a timing t4 when the preset time TA has elapsed. The machine main body 14 is stopped, and the operation of the compressor main body 14 is started again at this timing t4. At time t5 when the compressor main body 14 is continuously operated for a preset time TT, the compressor main body 14 is stopped, the flow path switching valve 40 is turned off, and the position is switched to the B position. Repeat above.

According to the air compressor 11 of the first embodiment described above, the compressed air in the outlet passage 31 is circulated to the bypass passage 39 by the flow path switching valve 40 when the compressor body 14 is stopped. The suction filter 29 can be self-cleaned with the compressed air remaining in the passage 31 and the aftercooler 34. Therefore, the suction filter 29 can be cleaned while suppressing a decrease in energy efficiency. Therefore, since the clogging of the suction filter 29 can be prevented, it is possible to prevent the performance of the compressor from being reduced due to a reduction in the amount of intake air from the suction port 12 that occurs when the suction filter 29 is clogged.
Further, it is possible to prevent galling and damage of the orbiting scroll 22 and the fixed scroll 24 due to the compression chamber 23 being in a negative pressure state during operation, which occurs when the suction filter 29 is completely clogged. Furthermore, in this case, since the outside air containing dust from a face seal (not shown) of the compressor body 14 other than the suction filter 29 is not sucked, abnormal wear or the like of a chip seal (not shown) of the compressor body 14 is prevented. can do. As a result, it can be used without causing a performance degradation at an early stage even in an environment with much dust.

  Further, when the compressor main body 14 is continuously operated for a preset time TT (for example, 10 minutes or 1 hour, etc.), the compressor body 14 is forcibly stopped and the flow path switching valve 40 is switched. The suction filter 29 can be periodically cleaned, and the suction filter 29 can be reliably prevented from being clogged.

  In addition, since the flow path switching valve 40 is provided not immediately after the discharge port 13 of the compressor body 14 but after the aftercooler 34 and immediately before the air tank 32, the amount of air flowing through the suction filter 29 can be secured. Therefore, the suction filter 29 can be sufficiently cleaned.

  Further, since the flow path switching valve 40 is turned off at the same time when the motor for driving the compressor main body 14 is turned off, it can be controlled by a common OFF signal.

  The time TA for turning off the compressor main body 14 and the time TB for turning off the flow path switching valve 40 may be made equal. In addition, since the air tank 32 side can be closed by the flow path switching valve 40 when it is OFF, there is a problem of reverse rotation and blowback sound when the compressor main body 14 is stopped without providing the check valve 33. There is no.

“Second Embodiment”
Next, the air compressor of 2nd Embodiment of this invention is demonstrated based on FIGS. In addition, about the site | part which is common in 1st Embodiment, it represents with the same name and the same code | symbol.

  In the second embodiment, a second flow path switching valve 42 is provided at a connection position between the bypass passage 39 and the suction passage 28. The second flow path switching valve 42 is a two-position three-way valve that is energized to close the bypass passage 39 and communicate the compressor body 14 and the suction filter 29 with the suction passage 28 as shown in FIG. As shown in FIG. 4, the position a is switched to the position b that is demagnetized and closes the compressor main body 14 side of the suction passage 28 and connects the suction filter 29 side of the suction passage 28 and the bypass passage 39. That is, the second flow path switching valve 42 has a position where the suction filter 29 and the suction port 12 communicate with each other, and a position b where the suction port 12 is closed and the compressed air from the bypass passage 39 is circulated to the suction filter 29. And can be switched.

  The control device (not shown) of the air compressor 11 excites the flow path switching valve 40 to the A position when driving the compressor body 14 by driving the motor, and the second flow path switching valve. As shown in FIG. 5, the bypass passage 39 is closed at the outlet passage 31 side, and the compressor body 14 and the air tank 32 are communicated with each other by the outlet passage 31, and the bypass passage 39 is excited. The suction passage 28 is closed, and the compressor body 14 and the suction filter 29 are communicated with each other through the suction passage 28. Then, the compressor main body 14 sucks air from the suction port 12 through the suction filter 29 and the suction passage 28, compresses it in the compression chamber 23, and guides it from the discharge port 13 to the air tank 32 through the lead-out passage 31.

  When the controller stops the compressor main body 14 at the same time, the flow path switching valve 40 is demagnetized to the B position at the same time, and the second flow path switching valve 42 is demagnetized to the b position. 4, the air tank 32 side of the outlet passage 31 is closed, the compressor body 14 side of the outlet passage 31 is connected to the bypass passage 39, and the compressor body 14 side of the suction passage 28 is connected. Is closed, and the suction filter 29 side of the suction passage 28 and the bypass passage 39 are connected. Then, the compressed air remaining between the check valve 33 and the flow path switching valve 40 in the outlet passage 31 and in the aftercooler 34 flows to the suction filter 29 through the bypass passage 39 and is discharged from the suction filter 29. At this time, the exhaust gas removes the dust trapped by the suction filter 29 and releases it to the outside air.

  For example, as shown in FIG. 6, the control device turns on the flow path switching valve 40 to switch to the A position at the timing t <b> 11 when the operation of the compressor main body 14 starts, and turns on the second flow path switching valve 42. And switch to position a. As a result, the outside air is sucked into the compressor main body 14 through the suction passage 28 and compressed through the suction passage 28, and is guided to the air tank 32 from the discharge port 13 through the lead-out passage 31. Only at the timing t12 when the compressor main body 14 is continuously operated, the compressor main body 14 is stopped, the flow path switching valve 40 is turned OFF to switch to the B position, and the second flow path switching valve 42 is turned OFF. Switch to position b. As a result, the compressed air remaining in the outlet passage 31 and the aftercooler 34 is discharged from the suction filter 29 to clean the suction filter 29.

  Then, at time t13 when a preset time TB has elapsed from timing t12, the flow path switching valve 40 is turned on again to switch to the A position, and then compressed from timing t12 to timing t14 when the preset time TA has elapsed. The machine body 14 is stopped, and at the same time t14, the operation of the compressor body 14 is started again. At the same time, the second flow path switching valve 42 is turned on to switch to the position a. Then, at the timing t15 when the compressor main body 14 is continuously operated for a preset time TT, the compressor main body 14 is stopped, the flow path switching valve 40 is turned OFF to switch to the B position, and the second flow The path switching valve 42 is turned off to switch to the b position. Repeat above.

  According to the second embodiment described above, when the compressor main body 14 is stopped, the compressed air in the outlet passage 31 is circulated to the bypass passage 39 by the flow path switching valve 40 and the second flow path switching valve 42 is used. Since the suction port 12 side of the suction passage 28 is closed and the compressed air from the bypass passage 39 is circulated to the suction filter 29, the compressed air remaining in the lead-out passage 31 and the aftercooler 34 is passed through the suction filter 29 without waste. The suction filter 29 can be reliably cleaned. Further, the check valve 33 may not be provided as in the first embodiment.

  In the first and second embodiments, a scroll type air compressor is taken as an example. However, the present invention is not limited to this, and a reciprocating type, a screw type or the like may be used as long as the compressor has a suction filter.

BRIEF DESCRIPTION OF THE DRAWINGS It is the block diagram which made the cross section the part which shows the air compressor of 1st Embodiment of this invention, Comprising: The stop state of a compressor main body is shown. BRIEF DESCRIPTION OF THE DRAWINGS It is the block diagram which made the cross section partially showing the air compressor of 1st Embodiment of this invention, Comprising: The driving | running state of a compressor main body is shown. It is a timing chart which shows the operation timing of the compressor main part and the channel change valve in the air compressor of a 1st embodiment of the present invention. It is the block diagram which made the cross section the part which shows the air compressor of 2nd Embodiment of this invention, Comprising: The stop state of a compressor main body is shown. It is the block diagram which made the cross section the part which shows the air compressor of 2nd Embodiment of this invention, Comprising: The driving | running state of a compressor main body is shown. It is a timing chart which shows the operation timing of the main part of a compressor in the air compressor of a 2nd embodiment of the present invention, a channel change valve, and the 2nd channel change valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Air compressor 12 Suction port 13 Discharge port 14 Compressor main body 22 Orbiting scroll 23 Compression chamber 24 Fixed scroll 28 Suction passage 29 Suction filter 31 Derivation passage 39 Bypass passage 40 Flow path switching valve 42 2nd flow path switching valve

Claims (4)

A compressor body that compresses the air sucked from the suction port and discharges it from the discharge port;
A suction passage for guiding outside air to the suction port via a suction filter;
A lead-out passage for guiding compressed air to the outside from the discharge port;
In an air compressor having
A bypass passage connecting the outlet passage and the suction passage;
A flow path switching valve is provided at a connection position between the outlet passage and the bypass passage,
The flow path switching valve guides compressed air from the discharge port to the outside through the outlet passage when the compressor body is in operation, and passes the compressed air from the outlet passage to the bypass passage when the compressor body is stopped. An air compressor characterized by switching so as to be distributed. The air compressor according to claim 1.
A second flow path switching valve is provided at a connection position between the bypass passage and the suction passage,
The second flow path switching valve causes the suction filter and the suction port to communicate with each other when the compressor body is in operation, and closes the suction port side when the compressor body is stopped, and compressed air from the bypass passage. Is switched so as to circulate through the suction filter. The air compressor according to claim 1 or 2,
An air compressor, wherein the compressor body is stopped when the compressor body is continuously operated for a preset time. The air compressor according to any one of claims 1 to 3,
The compressor main body has a fixed scroll and a turning scroll disposed rotatably to face the fixed scroll, and is a compression chamber formed between the fixed scroll and the turning scroll from the suction port. An air compressor characterized by being of a scroll type that compresses sucked air and discharges it from the discharge port.

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