JP7448367B2 - compressor - Google Patents

Description

The present invention relates to a compressor equipped with a tank that stores air compressed by a compressor main body.

The compressor of Patent Document 1 includes a motor, a compressor main body that is driven by the motor and compresses air, a tank that stores the air compressed by the compressor main body, and supplies the compressed air stored in the tank to the outside. The tank is equipped with a compressed air pipe for detecting the pressure inside the tank, a pressure sensor for detecting the pressure inside the tank, and a control device. When the pressure detected by the pressure sensor rises to the operating pressure, the control device enters a standby state (specifically, a stopped state or no-load operating state) that stops the supply of compressed air from the compressor main body to the tank. Then, when the pressure detected by the pressure sensor falls to the return pressure, the system switches to a load operating state in which the supply of compressed air from the compressor main body to the tank is restored.

Japanese Patent Application Publication No. 01-104990

Condensate condenses on the inner surface of the tank and accumulates at the bottom of the tank. This drain becomes a cause of tank corrosion. Therefore, it is conceivable to provide a drain discharge device that is controlled by a control device and discharges the drain in the tank to the outside. In this case, it is conceivable to estimate the amount of drain generated in the tank and fix the drain discharge time and drain interval.

However, the above-mentioned operating pressure can be set and changed based on the user's request, energy saving, etc. As the operating pressure decreases, the amount of condensate generated within the tank also decreases. Therefore, if the drain discharge time and drain interval remain fixed, the drain discharge time will become longer than necessary, or the drain discharge interval will become shorter than necessary. Therefore, more wasteful air is released from the tank as the drain is discharged.

The first invention has been made in view of the above-mentioned problems, and one of its objects is to suppress wasteful release of air from the tank. The second invention prevents drain from remaining and returning to the tank when the electromagnetic on-off valve constituting the drain discharge device is switched from the communication state to the cutoff state, and prevents condensed water from dripping on the electromagnetic on-off valve. The objective is to prevent problems with electromagnetic on-off valves.

In order to solve the above problems, the configurations described in the claims are applied. The first invention includes a plurality of means for solving the above problems, and one example thereof includes a motor, a compressor main body that is driven by the motor and compresses air, and a compressor main body that is driven by the motor and compresses air. a tank for storing compressed air; a compressed air pipe for supplying the compressed air stored in the tank to the outside; a pressure sensor for detecting the pressure in the tank; and a drain in the tank for discharging the drain to the outside. and a drain discharge device that switches to a standby state in which the supply of compressed air from the compressor main body to the tank is stopped when the pressure detected by the pressure sensor rises to an operating pressure, and then the pressure sensor a control device having a function of switching to a load operating state of restoring the supply of compressed air from the compressor main body to the tank when the detected pressure drops to a return pressure, and a function of controlling the drain discharge device; In the compressor, the control device changes at least one of a drain discharge time and a drain discharge interval of the drain discharge device in accordance with a change in the setting of the operating pressure.
A second invention includes a motor, a compressor main body that is driven by the motor and compresses air, a tank that stores the air compressed by the compressor main body, and the compressed air stored in the tank is delivered to the outside. A supply compressed air pipe, a pressure sensor that detects the pressure in the tank, a drain discharge device that discharges drain in the tank to the outside, and when the pressure detected by the pressure sensor rises to an operating pressure. , switching to a standby state in which the supply of compressed air from the compressor main body to the tank is stopped, and then, when the pressure detected by the pressure sensor falls to the return pressure, the supply of compressed air from the compressor main body to the tank is switched to a standby state. In the compressor, the compressor includes a control device having a function of switching to a load operating state to restore the supply of compressed air, and a function of controlling the drain discharge device, wherein the drain discharge device is an electromagnetic controller controlled by the control device. It has an on-off valve, a strainer provided upstream of the electromagnetic on-off valve, and a straight joint or cheese joint connected to the upper side of the strainer, and the strainer and the straight joint or the cheese joint are connected to the tank. The valve is located above the bottom of the valve and extends in the vertical direction, and is arranged so as not to overlap the electromagnetic on-off valve when viewed from the vertical direction.

According to the first invention, wasteful release of air from the tank can be suppressed. According to the second invention, when the electromagnetic on-off valve is switched from the communication state to the cutoff state, the drain is prevented from remaining and returning to the tank, and the condensed water is prevented from dripping on the electromagnetic on-off valve and the electromagnetic on-off valve is closed. This can prevent problems from occurring.

Note that problems, configurations, and effects other than those described above will be made clear by the following description.

FIG. 1 is a front view showing the structure of a compressor in a first embodiment to which the present invention is applied. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a rear view and a left side view showing the peripheral structure of a tank in a first embodiment to which the present invention is applied. FIG. 2 is an enlarged front view of part III in FIG. 1, showing the main structure of the drain discharge device in the first embodiment to which the present invention is applied. 1 is a block diagram showing the functional configuration of a control device in a first embodiment to which the present invention is applied together with related equipment; FIG. It is a time chart for explaining the processing contents of the control device in the first embodiment to which the present invention is applied, and shows a case where the operating pressure and the return pressure are initial values. It is a time chart for explaining the processing contents of the control device in the first embodiment to which the present invention is applied, and shows a case where the operating pressure and the return pressure are changed values lower than the initial values. It is a time chart for explaining the processing content of the control device in the second embodiment to which the present invention is applied, and shows a case where the operating pressure and the return pressure are changed values lower than the initial values. It is a time chart for explaining the processing content of the control device in the first modified example to which the present invention is applied. It is a block diagram showing the functional configuration of a control device in a second modified example to which the present invention is applied together with related equipment. It is a time chart for explaining the processing content of the control device in a third modified example to which the present invention is applied. It is a front view showing main part structure of the drain discharge device in the 4th modification to which the present invention is applied. It is a front view showing the principal part structure of the drain discharge device in the 5th modification to which the present invention is applied. It is a front view showing the principal part structure of the drain discharge device in the 6th modification to which the present invention is applied.

A first embodiment to which the present invention is applied will be described with reference to the drawings.

FIG. 1 is a front view showing the structure of the compressor in this embodiment, with most of the front panel seen through. FIG. 2(a) is a rear view showing the peripheral structure of the tank in this embodiment, and FIG. 2(b) is a left side view seen from the direction of arrow B in FIG. 2(a). FIG. 3 is an enlarged front view of part III in FIG. 1, showing the main structure of the drain discharge device in this embodiment.

The compressor 1 of this embodiment includes a motor 2, a compressor main body 3 that is driven by the motor 2 and compresses air, a tank 4 that stores the air compressed by the compressor main body 3, and a drain in the tank 4. It includes a drain discharge device 5 that discharges water to the outside, and a control device 6 (see FIG. 4 described later) that controls the motor 2 and the drain discharge device 5.

The compressor 1 also includes a housing 7 that houses the above-mentioned equipment. The housing 7 has a base 8 , a front panel 9 , a left side panel 10 , a right side panel 11 , a rear panel 12 , and a top panel 13 . A pedestal 14 is fixed onto the base 8 via anti-vibration rubber. The tank 4 is fixed horizontally on the frame 14 via a bracket 15. A mounting base 16 is welded to the upper side of the tank 4. The motor 2 and the compressor main body 3 are arranged on the mounting base 16. A user interface 17 is provided on the front panel 9. The user interface 17 has a plurality of operation switches and a monitor.

The compressor main body 3 is, for example, a reciprocating type, and includes a cylinder, a piston, a suction valve, and a discharge valve. The rotational motion of the motor 2 is transmitted via a pulley, a belt, etc., and is further converted into a reciprocating motion and transmitted to a piston via a crankshaft, etc. As a result, the piston within the cylinder reciprocates, and the volume of the working chamber within the cylinder changes. The suction valve is open and the discharge valve is closed, increasing the volume of the working chamber, thereby sucking air into the working chamber (suction process). Thereafter, the suction valve is closed, the discharge valve is closed, and the volume of the working chamber is reduced, thereby compressing the air in the working chamber (compression process). Thereafter, the suction valve is closed and the discharge valve is opened, and compressed air is discharged from the working chamber (discharge process).

Compressed air discharged from the compressor main body 3 flows into the tank 4 via the discharge pipe 18. The compressed air stored in the tank 4 is supplied to the outside of the compressor 1 via a compressed air pipe 19. A pressure sensor 20 is provided in the tank 4. Pressure sensor 20 detects the pressure within tank 4 and outputs it to control device 6 .

The drain discharge device 5 includes a suction pipe 21 arranged inside the tank 4, a guide pipe 23 arranged outside the tank 4 and connected to the suction pipe 21 via an elbow joint 22A, and an elbow joint 22B. A straight joint 24 that is connected to the guide pipe 23 and extends in the vertical direction, a strainer 25 that is connected to the lower side of the straight joint 24 and extends in the vertical direction, and a strainer 25 that is fixed to the base 8 and is connected to the elbow joint 22C through the elbow joint 22C. It has an electromagnetic on-off valve 26 connected to the strainer 25 and a discharge pipe 27 connected to the electromagnetic on-off valve 26 and extending in the left-right direction. Note that the guide tube 23 and the discharge tube 27 are preferably made of resin and have flexibility from the viewpoint of maintainability and the like.

The electromagnetic on-off valve 26 is a two-way valve controlled by the control device 6, and can be switched from a blocking state in which the right port and the left port are cut off to a communicating state in which the right port and the left port are communicated. When the electromagnetic on-off valve 26 is switched to the communicating state, the difference between the pressure on the inlet side of the suction pipe 21 (that is, inside the tank 4) and the pressure on the outlet side of the discharge pipe 27 causes the Drain collected at the bottom flows into the suction pipe 21, the guide pipe 23, the straight joint 24, the strainer 25, the electromagnetic on-off valve 26, and the discharge pipe 27 in that order, and is discharged to the outside of the compressor 1. The strainer 25 removes foreign matter from the drain.

If the amount of condensate generated in the tank 4 exceeds expectations for some reason, there is a possibility that the condensate will remain in the drain discharge device 5 when the electromagnetic on-off valve 26 is switched from the communication state to the cutoff state. In the drain discharge device 5 of this embodiment, the capacity of the straight joint 24 supplements the capacity of the strainer 25. This allows the drain to remain in the strainer 25 and the straight joint 24, and prevents the drain from returning to the tank 4.

The strainer 25 and the straight joint 24 provided on the upstream side of the electromagnetic on-off valve 26 are arranged so as not to overlap the electromagnetic on-off valve 26 when viewed from the vertical direction. Here, a case is assumed in which the strainer 25 and the straight joint 24 are arranged so as to overlap the electromagnetic on-off valve 26 when viewed from the vertical direction. In this case, water condensed on the outer surfaces of the strainer 25 and the straight joint 24 may drip onto the electromagnetic on-off valve 26, potentially causing a malfunction of the electromagnetic on-off valve 26. In this embodiment, the above-described arrangement of the strainer 25 and the straight joint 24 prevents malfunctions of the electromagnetic on-off valve 26.

The discharge pipe 27 provided on the downstream side of the electromagnetic on-off valve 26 is arranged such that the inlet side is higher than the outlet side. Here, assume that the inlet side of the discharge pipe 27 is lower than the outlet. In this case, water condensed on the outer surface of the discharge pipe 27 may drip onto the electromagnetic on-off valve 26, potentially causing a malfunction of the electromagnetic on-off valve 26. In this embodiment, the above-described arrangement of the discharge pipe 27 prevents malfunctions of the electromagnetic on-off valve 26.

Next, the control device 6, which is a main part of this embodiment, will be explained using FIGS. 4 to 6. FIG. 4 is a block diagram showing the functional configuration of the control device in this embodiment together with related equipment. 5 and 6 are time charts for explaining the processing contents of the control device in this embodiment. FIG. 5 shows the case where the operating pressure and the return pressure are initial values, and FIG. 6 shows the case where the operating pressure and the return pressure are changed values lower than the initial values.

The control device 6 includes an arithmetic control unit (eg, CPU) that executes arithmetic processing and control processing based on a program, and a storage unit (eg, ROM, RAM) that stores the program and the results of the arithmetic processing. The control device 6 has an operation control section 28 and a drain control section 29 as a functional configuration.

The motor 2 is connected to a commercial power source 31 via an electromagnetic contactor 30. The operation control unit 28 of the control device 6 controls the electromagnetic contactor 30 to switch between driving and stopping the motor 2 in accordance with the operation of the switch on the user interface 17. Further, the operation control unit 28 of the control device 6 executes an intermittent operation control mode in which the electromagnetic contactor 30 is controlled to switch between driving and stopping the motor 2 according to the pressure detected by the pressure sensor 20. The intermittent operation control mode will be explained in detail.

The operation control unit 28 of the control device 6 stores a preset initial value P _A1 of the operating pressure and an initial value P _B1 of the return pressure. If the operating pressure and return pressure are set at their initial values, as shown in _FIG . 5, when the pressure detected by the pressure sensor 20 rises to the operating pressure P is opened to stop the motor 2 and switch to a standby state in which the supply of compressed air from the compressor main body 3 to the tank 4 is stopped. After that, when the pressure detected by the pressure sensor 20 drops to the return pressure P _B1 , the contacts of the electromagnetic contactor 30 are closed and the motor 2 is driven to supply compressed air from the compressor main body 3 to the tank 4. Switch to the load operating state that restores the load.

The operation control unit 28 of the control device 6 sets the operating pressure P _A2 (however, P _A2 < P _A1 ) and the return pressure P _B2 (however, P _B2 < P _B1 ), for example, in accordance with the input from the user interface 17. change. In this case, as shown in FIG. 6, when the pressure detected by the pressure sensor 20 rises to the operating pressure _PA2 , the contacts of the electromagnetic contactor 30 are opened to stop the motor 2 and switch to a standby state. Thereafter, when the pressure detected by the pressure sensor 20 drops to the return pressure P _B2 , the contacts of the electromagnetic contactor 30 are closed to drive the motor 2 and switch to a load operating state.

The drain control unit 29 of the control device 6 stores a set value D ₁ of the drain discharge time and a set value I ₁ of the drain discharge interval, which correspond to the initial value _PA1 of the operating pressure and the initial value P _B1 of the return pressure. Then, the drain control unit 29 of the control device 6 calculates the cumulative time of the load operation state using a timer. If the operating pressure and return pressure are set at their initial values, as shown in _FIG . Switch to communication state and start draining. When the set value _D1 of the drain discharge time has elapsed since the start of drain discharge, the electromagnetic on-off valve 26 is switched to the cut-off state and the drain discharge is ended. Then, the cumulative time of the load operation state is reset and the calculation is performed again.

The drain control unit 29 of the control device 6 changes the set value of the drain discharge time in accordance with the above-mentioned changes in the operating pressure and return pressure settings. In detail _, for example, the amount of drain generated in the tank 4 decreases due to a decrease in the operating pressure P _A1 to P _A2 and a decrease in the return pressure P _B1 to P _B2 . D Decrease to ₂ . In this case, as shown in FIG. 6, when the set value _D2 of the drain discharge time has elapsed after the start of drain discharge, the electromagnetic on-off valve 26 is switched to the cut-off state and the drain discharge is ended.

As described above, in this embodiment, the control device 6 changes the setting of the drain discharge time in accordance with the setting change of the operating pressure and the return pressure. Thereby, wasteful release of air from the tank 4 can be suppressed.

In the first embodiment, the control device 6 changes the setting of the operating pressure and the return pressure in accordance with the input from the user interface 17, and changes the setting of the drain discharge time in accordance with the setting change. Although explained, it is not limited to this. For example, the control device 6 may change the setting of only the operating pressure in response to an input from the user interface 17, and may change the setting of the drain discharge time in accordance with the setting change. Furthermore, the control device 6 uses the detection results of the pressure sensor 20 to calculate the load factor of the compressor (specifically, the duration of the load operation state/(the duration of the load operation state + the duration of the standby state)). However, based on this, the setting of only the operating pressure or both the operating pressure and the return pressure may be changed, and the drain discharge time may be changed in accordance with the setting change.

A second embodiment of the present invention will be described using FIG. 7. FIG. 7 is a time chart for explaining the processing contents of the control device in this embodiment, and shows a case where the operating pressure and the return pressure are changed values lower than the initial values. In addition, in this embodiment, parts equivalent to those in the first embodiment are given the same reference numerals, and description thereof will be omitted as appropriate.

The drain control unit 29 of the control device 6 of this embodiment changes the setting value of the drain discharge interval in accordance with the setting change of the operating pressure and the return pressure described above. In detail, for example, since the amount of drain generated in the tank 4 decreases due to a decrease in the operating pressure from P _A1 to P _A2 and a decrease from return pressure P _B1 to P _B2 , the drain discharge interval setting value I1 _decreases . I increases to ₂ . In this case, as shown in FIG. 7, when the cumulative time of the load operation state after drain discharge ends reaches the set value _I2 of the drain discharge interval, the electromagnetic on-off valve 26 is switched to the communication state and drain discharge is started. do.

As described above, in this embodiment, the control device 6 changes the setting of the drain discharge interval in accordance with the setting change of the operating pressure and the return pressure. Thereby, wasteful release of air from the tank 4 can be suppressed.

In addition, in the second embodiment, the control device 6 changes the setting of the operating pressure and the return pressure in accordance with the input from the user interface 17, and changes the setting of the drain discharge interval in accordance with the setting change. Although explained, it is not limited to this. For example, the control device 6 may change the setting of only the operating pressure in response to an input from the user interface 17, and may change the setting of the drain discharge interval in accordance with the setting change. Further, the control device 6 calculates the load factor of the compressor using the detection result of the pressure sensor 20, changes the setting of only the operating pressure or both the operating pressure and the return pressure based on this, and changes the setting. The drain discharge interval may be changed accordingly.

In the first embodiment or a modification thereof, the control device 6 may change the setting of the drain discharge time in accordance with the setting change of the operating pressure and the return pressure or the setting change of only the operating pressure. In the embodiment or its modification, the control device 6 has been described using an example in which the setting of the drain discharge interval is changed in response to a setting change of the operating pressure and return pressure or a setting change of only the operating pressure. Not limited to. The control device 6 may change the setting of both the drain discharge time and drain interval in accordance with the setting change of the operating pressure and the return pressure or the setting change of only the operating pressure.

Further, in the first and second embodiments, although not particularly described, the control device 6 may adjust the timing to start drain discharge according to the pressure detected by the pressure sensor 20. Such a modification will be explained using FIG. 8. FIG. 8 is a time chart for explaining the processing content of the control device in the first modification. The control device 6 controls the pressure detected by the pressure sensor 20 to reach a predetermined pressure (specifically, the difference between the operating pressure and the return pressure) when the cumulative time of the load operation state reaches the set value of the drain discharge interval (time t1). It is determined whether or not the pressure is higher than the return pressure (for example, the pressure is set to be higher than the return pressure by the drop width ΔP of the pressure in the tank 4 due to drain discharge). If the pressure detected by the pressure sensor 20 is lower than the predetermined pressure, the electromagnetic on-off valve 26 is not switched to the communicating state, and the drain in the tank 4 is not discharged. Thereafter, after the pressure detected by the pressure sensor 20 becomes equal to or higher than a predetermined pressure (time t2), the electromagnetic on-off valve 26 is switched to a communicating state, and the drain in the tank 4 is discharged. In this modification, it is possible to prevent the pressure inside the tank 4 from becoming lower than the return pressure during drain discharge.

Further, in the first and second embodiments, the compressor 1 is a constant speed machine in which the rotation speed of the motor 2 is fixed, but the invention is not limited to this, and the rotation speed of the motor 2 is fixed. It may be a variable speed machine. Such a modification will be explained using FIG. 9. FIG. 9 is a block diagram showing the functional configuration of the control device in the second modification together with related equipment. The control device 6 of this modification is configured so that the pressure detected by the pressure sensor 20 becomes a control pressure (specifically, a pressure set to be lower than the operating pressure and higher than or equal to the return pressure). , variably controls the rotation speed of the motor 2 via the inverter 32. Then, when the rotation speed of the motor 2 reaches the lower limit value and the pressure detected by the pressure sensor 20 rises to the operating pressure, the motor 2 is stopped via the inverter 32 and switched to a standby state. Thereafter, when the pressure detected by the pressure sensor 20 drops to the return pressure, the motor 2 is driven via the inverter 32 and switched to a load operating state.

Furthermore, the control device 6 controls the pressure detected by the pressure sensor 20 to reach a predetermined pressure (specifically, between the operating pressure and the return pressure) when the cumulative time of the load operation state reaches the set value of the drain discharge interval. For example, it is determined whether or not the pressure is higher than the return pressure by the drop width ΔP of the pressure in the tank 4 due to drain discharge. If the pressure detected by the pressure sensor 20 is lower than the predetermined pressure, the electromagnetic on-off valve 26 is not switched to the communicating state, and the drain in the tank 4 is not discharged. Thereafter, the rotation speed of the motor 2 is increased via the inverter 32, and after the pressure detected by the pressure sensor 20 reaches a predetermined pressure or more, the electromagnetic on-off valve 26 is switched to the communication state, and the drain in the tank 4 is discharged. . In this case, it is possible to prevent the pressure inside the tank 4 from becoming lower than the return pressure.

Further, in the first and second embodiments, the control device 6 calculates the cumulative time of the load operation state, and when the cumulative time of the load operation state reaches the set value of the drain discharge interval, the control device 6 controls the electromagnetic on-off valve. 26 is switched to the communicating state and the drain in the tank 4 is discharged, but the present invention is not limited to this. The control device 6 calculates the load factor of the compressor using the detection result of the pressure sensor 20, and switches the electromagnetic on-off valve 26 to the communication state when the cumulative value of the load factor reaches the set value of the drain discharge interval. , the drain in the tank 4 may be discharged.

Another modification will be explained using FIG. 10. FIG. 10 is a time chart for explaining the processing content of the control device in the third modification. The control device 6 of this modification switches the electromagnetic on-off valve 26 to the communication state and discharges the drain in the tank 4 when the duration of the standby state reaches the set value _I3 of the drain discharge interval (time t3). do. In addition, even if the duration of the standby state does not reach the set value _I3 of the drain discharge interval, a preset predetermined time T of the duration of the standby state (in detail, for example, if the duration of the standby state is switched to When the cumulative time accumulated after the elapse of half of the time required for the internal temperature of tank 4 to drop to the outside temperature (time t4) reaches the set value _I3 of the drain discharge interval, the electromagnetic The on-off valve 26 is switched to a communicating state, and the drain in the tank 4 is discharged. At the end of drain discharge, the cumulative time mentioned above is reset and calculated again. In this modification, the amount of drain stored in the tank 4 can be suppressed.

Furthermore, in the first and second embodiments, the control device 6 has been described by taking as an example a case where the control device 6 executes an intermittent operation control mode in which the motor 2 is stopped and driven, thereby switching between a standby state and a load operation state. , but not limited to this. For example, the control device 6 may execute a continuous operation control mode that switches between a standby state and a load operation state while driving the motor 2. In this continuous operation control mode, the control device 6 switches to a standby state by driving the unloader mechanism and fixing the suction valve in the open state, and stops the unloading mechanism to enable the suction valve to open and close. By doing so, it switches to the load operation state. The control device 6 may calculate the load factor of the compressor using the detection result of the pressure sensor 20, and select and execute one of the intermittent operation control mode and the continuous operation control mode based on this.

By the way, in the above-mentioned drain discharge device 5, when a malfunction occurs in the electromagnetic on-off valve 26, it becomes difficult to discharge the drain. Therefore, the drain discharge device 5 may further include a manual on-off valve. Such a modification will be explained in detail using FIGS. 11 to 13. Note that in each modification, parts equivalent to those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

FIG. 11 is a front view showing the main structure of the drain discharge device in the fourth modification. The drain discharge device 5 of this modification has a cheese joint 33 that is connected to the upstream side of the strainer 25 and extends in the vertical direction together with the strainer 25 instead of the straight joint 24. , to supplement the capacity of the strainer 25. The elbow joint 22B and the strainer 25 are connected to the upper and lower ports of the cheese joint 33, respectively, and the manual on-off valve 34 is connected to the right port of the cheese joint 33. If a malfunction occurs in the electromagnetic on-off valve 26, the user or a service person can discharge the drain by operating the manual on-off valve 34.

FIG. 12 is a front view showing the main structure of the drain discharge device in the fifth modification. In the drain discharge device 5 of this modification, the elbow joint 22B and the strainer 25 are connected to each other without using the straight joint 24. Moreover, the drain discharge device 5 has a cheese joint 35 provided between the strainer 25 and the electromagnetic on-off valve 26 instead of the elbow joint 22C. The strainer 25 and the electromagnetic on-off valve 26 are connected to the upper and left ports of the cheese joint 35, respectively, and the manual on-off valve 34 is connected to the right port of the cheese joint 33. If a malfunction occurs in the electromagnetic on-off valve 26, the user or a service person can discharge the drain by operating the manual on-off valve 34. Moreover, since the manual on-off valve 34 is arranged downstream of the strainer 25, it is possible to suppress the occurrence of malfunctions of the manual on-off valve 34 due to foreign matter in the drain.

FIG. 13 is a front view showing the main structure of the drain discharge device in the sixth modification. In the drain discharge device 5 of this modification, the elbow joint 22B and the strainer 25 are connected to each other without using the straight joint 24. Moreover, the drain discharge device 5 has an electromagnetic on-off valve 26A that is a three-way valve instead of the electromagnetic on-off valve 26 that is a two-way valve. The electromagnetic on-off valve 26A selects one of the left port and the lower port to communicate with the right port. An elbow joint 22C and a discharge pipe 27 are connected to the right and left ports of the electromagnetic on-off valve 26A, respectively, and a manual on-off valve 34 is connected to the lower port of the electromagnetic on-off valve 26A. If a malfunction occurs in the electromagnetic on-off valve 26A, the user or a service person can discharge the drain by operating the manual on-off valve 34. Moreover, since the manual on-off valve 34 is arranged downstream of the strainer 25, it is possible to suppress the occurrence of malfunctions of the manual on-off valve 34 due to foreign matter in the drain. Although not shown, the drain discharge device 5 may have an electromagnetic on-off valve that is a four-way valve instead of the electromagnetic on-off valve 26 that is a two-way valve, and a plug plug is inserted into the empty port of this electromagnetic on-off valve. Just install it.

In the first and second embodiments, the compressor main body 3 is of a reciprocating type (in detail, compression is performed by reciprocating movement of a piston), but the compressor main body 3 is not limited to this. For example, it may be of a scroll type (specifically, compression is performed by the rotational movement of a scroll) or a screw type (specifically, compression is performed by the rotational movement of a screw). Furthermore, in the first and second embodiments, the compressor 1 has been described as an example of a case in which the compressor 1 is a package type that includes a casing 7 that houses the equipment, but the compressor 1 is not limited to this and may be in a package type. Good too.

DESCRIPTION OF SYMBOLS 1... Compressor, 2... Motor, 3... Compressor main body, 4... Tank, 5... Drain discharge device, 6... Control device, 19... Compressed air piping, 20... Pressure sensor, 24... Straight joint, 25... Strainer, 26, 26A...Solenoid on-off valve, 32...Inverter, 33...Cheese joint, 34...Manual on-off valve

Claims (11)

motor and
a compressor main body that is driven by the motor and compresses air;
a tank for storing air compressed by the compressor main body;
compressed air piping that supplies compressed air stored in the tank to the outside;
a pressure sensor that detects the pressure within the tank;
a drain discharge device for discharging the drain in the tank to the outside;
When the pressure detected by the pressure sensor rises to an operating pressure, the compressor body switches to a standby state in which the supply of compressed air to the tank is stopped, and then the pressure detected by the pressure sensor returns. A compressor comprising: a control device having a function of switching to a load operating state of restoring the supply of compressed air from the compressor main body to the tank when the pressure has decreased to a certain level, and a control device having a function of controlling the drain discharge device. In,
The compressor is characterized in that the control device changes at least one of a drain discharge time and a drain discharge interval of the drain discharge device in accordance with a change in the setting of the operating pressure. The compressor according to claim 1,
The compressor, wherein the control device reduces the drain discharge time in accordance with a decrease in the operating pressure. The compressor according to claim 1,
The compressor, wherein the control device increases the drain discharge interval as the operating pressure decreases. The compressor according to claim 1,
The control device controls the pressure detected by the pressure sensor to be between the working pressure and the return pressure when the cumulative time of the loaded operation state or the cumulative value of the load rate reaches a set value of a drain discharge interval. If the pressure is lower than a predetermined pressure, the drain discharge device is controlled so as not to discharge the drain in the tank, and after the pressure detected by the pressure sensor becomes equal to or higher than the predetermined pressure, the drain discharge device is controlled so as not to discharge the drain in the tank. A compressor, characterized in that the drain discharge device is controlled to discharge drain therein. The compressor according to claim 1,
an inverter that variably controls the rotation speed of the motor;
The control device controls the pressure detected by the pressure sensor to be between the working pressure and the return pressure when the cumulative time of the loaded operation state or the cumulative value of the load rate reaches a set value of the drain discharge interval. If the pressure is lower than a preset predetermined pressure, the drain discharge device is controlled so as not to discharge the drain in the tank, and then the rotation speed of the motor is increased via the inverter, and the rotation speed is increased to detect the pressure detected by the pressure sensor. The compressor is characterized in that the drain discharge device is controlled so that the drain in the tank is discharged after the pressure exceeds the predetermined pressure. The compressor according to claim 1,
The control device controls the drain discharge device to discharge drain from the tank when the duration of the standby state reaches a set value of a drain discharge interval, and Even if the set value of the drain discharge interval is not reached, the cumulative time remaining after the elapse of a preset predetermined time of the duration of the standby state has reached the set value of the drain discharge interval. The compressor is characterized in that the drain discharge device is controlled to discharge the drain in the tank. The compressor according to claim 1,
The drain discharge device includes an electromagnetic on-off valve controlled by the control device, and a strainer provided upstream of the electromagnetic on-off valve,
The compressor is characterized in that the strainer is arranged so as not to overlap the electromagnetic on-off valve when viewed from the vertical direction. The compressor according to claim 7,
The compressor is characterized in that the drain discharge device has a straight joint connected to the upstream side of the strainer and extending vertically together with the strainer. The compressor according to claim 7,
A compressor characterized in that the drain discharge device includes a cheese joint connected upstream of the strainer and extending vertically together with the strainer, and a manual on-off valve connected to the cheese joint. The compressor according to claim 7,
A compressor, wherein the drain discharge device has a manual on-off valve provided downstream of the strainer. motor and
a compressor main body that is driven by the motor and compresses air;
a tank for storing air compressed by the compressor main body;
compressed air piping that supplies compressed air stored in the tank to the outside;
a pressure sensor that detects the pressure within the tank;
a drain discharge device for discharging the drain in the tank to the outside;
When the pressure detected by the pressure sensor rises to an operating pressure, the compressor body switches to a standby state in which the supply of compressed air to the tank is stopped, and then the pressure detected by the pressure sensor returns. A compressor comprising: a control device having a function of switching to a load operating state of restoring the supply of compressed air from the compressor main body to the tank when the pressure has decreased to a certain level, and a control device having a function of controlling the drain discharge device. In,
The drain discharge device includes an electromagnetic on-off valve controlled by the control device, a strainer provided upstream of the electromagnetic on-off valve , and a straight joint or cheese joint connected above the strainer ,
The strainer and the straight joint or the cheese joint are located above the bottom of the tank and extend in the vertical direction, and are arranged so as not to overlap the electromagnetic on-off valve when viewed from the vertical direction. Compressor features.

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