JPH05157055A - Controller of air compressor - Google Patents

Abstract

PURPOSE:To continue to use collected data for protection maintenance even when a controller is out of order. CONSTITUTION:A 7 memory 8 in which at least the driving time and the number of unloading of a compressor main body are stored, is mounted on an MCU 6 loaded on a controller in such a way that the memory can be freely removed, and stored data is thus maintained even when the memory is removed from the MCU 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an air compressor, and in particular, even if the control device fails, the preventive maintenance data such as the operating time of the compressor body and the number of times of unloading are continuously used. , An air compressor control device suitable for controlling a compressor.

[0002]

2. Description of the Related Art In a conventional device, preventive maintenance data such as the operating time of an air compressor and the number of times of unloading (a condition in which the capacity regulator is controlled to make the discharge air volume zero while the compressor is operating) are stored. The data is stored in a random access memory (hereinafter referred to as “RAM”) and is backed up by a battery for data storage even in the case of power failure.

One related to this type of device is, for example, the technique described in Japanese Patent Publication No. 1-33676.

[0004]

In the above-mentioned prior art, when the control device fails, all the preventive maintenance data such as the operating time of the compressor body and the number of unloads stored in the RAM cannot be used. In addition, if a power failure occurs when a battery malfunctions and the voltage drops, the data stored in the RAM until then cannot be used. In this case, the driving time must be estimated from the driving diary. That is,
In the prior art, no consideration is given to the failure of the control device, and there is a problem that the preventive maintenance data is lost when the control device fails.

Further, in the prior art, the voltage used for storing the control data of the compressor even in the event of a power failure is measured without applying a load current to the battery. The voltage cannot be measured. Even if the battery is exhausted,
When there is no load, the voltage recovers to the original rated voltage, and when the load is connected, the voltage drops. That is, in the conventional technology,
There is a problem that the change in the battery voltage due to the presence or absence of a load is not taken into consideration, and even if the battery is exhausted, the exhausted state cannot be detected.

It is an object of the present invention to provide a control device even if it fails.
An object of the present invention is to provide a control device for an air compressor that can continuously use preventive maintenance data.

Another object of the present invention is to provide an air compressor control device capable of accurately detecting the exhaustion state of a battery.

[0008]

In order to achieve the above-mentioned object, according to the present invention, at least a memory for storing the operating time of the compressor body and the number of times of unloading is removably attached to and removed from the control device. Is also configured to hold stored data.

To achieve the above object, the present invention uses an electrically erasable read-only memory (hereinafter referred to as "E-EPROM") as the memory, which is different from the control device. It is mounted on a printed circuit board, the printed circuit board and a control device are connected by a connector, and the E / EPROM is mounted on an IC socket.

In order to achieve the above object, the present invention uses a RAM as the memory, mounts the RAM and a battery for holding data at the time of power failure on a printed board different from the control device, and The control device is connected by a connector.

In order to achieve the above-mentioned other objects, the present invention controls each part by a micro control unit (hereinafter referred to as "MCU") mounted on a control device of a compressor, and outputs control data of the compressor. In a controller of an air compressor having a memory protected by a battery so as to store even in the case of a power failure, an MC is used when the voltage of the battery is measured.
The relay excited by U, the resistance corresponding to the load connected to the battery by this relay, and the voltage value of the battery are measured,
And a voltage measuring device for outputting a measured value to the MCU.

Further, in order to achieve the above-mentioned other object,
The present invention is configured such that the above-mentioned MCU excites a relay at regular time intervals so that the battery voltage can be measured periodically.

And in order to achieve the above-mentioned other objects,
According to the present invention, the control device is connected to a host computer, and at least the operating time of the compressor, the number of times of unloading, and the preventive maintenance data of the battery voltage measurement result are managed on the host computer side.

[0014]

According to the first aspect of the present invention, at least a memory for storing the operating time of the compressor body and the number of times of unloading is removably attached to the control device, and the stored data is retained even if the memory is removed from the control device. Is configured as follows. That is, a non-volatile memory is used as the memory,
MC installed in the controller of the compressor in this non-volatile memory
The U stores data for preventive maintenance such as the operating time of the compressor and the number of times of unloading for each operation of the compressor. Then, the data stored in the non-volatile memory is used as a material for knowing the machine inspection time.

By the way, the nonvolatile memory is detachably attached to the control device. Therefore, when the control device fails, the nonvolatile memory is removed from the failed control device. Then, the non-volatile memory is attached to another normal control device. Thereby, the control can be continued without losing the preventive maintenance data, and the machine inspection time can be displayed.

Then, in order to know the machine inspection time, the following data is written in the non-volatile memory at a frequency of, for example, every hour.

(1) Operating time of the main motor of the compressor (2) Number of unloads (3) Elapsed time after delivery of the compressor Next, the following contents are displayed using the above data.

(1) Main body inspection: every preset operating time or every elapsed time after delivery (for example, 160
"Main body inspection" every 00 hours or every 2 years, whichever is shorter)
Is displayed.

(2) Auxiliary equipment inspection: every preset operating time or every years after delivery (eg 800
"Auxiliary machine inspection" is displayed every 0 hours or every year (shorter one).

(3) Grease replenishment: "Grease replenishment" is displayed every preset time (for example, every 8000 hours).

(4) Four-way solenoid valve inspection: "four-way solenoid valve inspection" is displayed for each preset unloading frequency.

As described above, the preventive maintenance data collected up to that point can be used by the control device after the replacement, and it is possible to accurately know the inspection timing of the compressor body.

Further, in the invention according to claim 2 of the present invention,
The E / EPROM is used as the memory.
The ROM is mounted on a printed circuit board different from the control device, the printed circuit board and the control device are connected by a connector, and in the claim 3, the E / EPROM is mounted on an IC socket. In claim 4, a RAM is used as the memory, and the RAM and a battery for holding data at the time of power failure are mounted on a printed circuit board different from the control device,
The printed circuit board and the controller are connected by a connector,
In either case, the memory storing the preventive maintenance data collected up to that point can be easily removed from the failed control unit,
It can be easily installed and used in a new control device that has not failed.

Further, in the invention according to claim 5 of the present invention, in order to control each part by the MCU mounted in the control device of the compressor and to store the control data of the compressor even in the case of a power failure, a battery is used. In a controller of an air compressor having a protected memory, an MC when measuring the voltage of the battery.
The relay excited by U, the resistance corresponding to the load connected to the battery by this relay, and the voltage value of the battery are measured,
And a voltage measuring device for outputting a measured value to the MCU. And the MCU installed in the control device of the compressor
Stores the compressor control data in a battery-protected memory even in the event of a power failure. The MCU also periodically measures the voltage of the battery. At the time of this voltage measurement, the MCU excites the relay and connects a resistor corresponding to the load to the battery. Then,
The voltage measuring device measures the voltage value of the battery and outputs it to the MCU. Therefore, the MCU determines whether or not the battery needs to be replaced based on the measured voltage value and outputs it.

As described above, according to the fifth aspect of the present invention, the resistance corresponding to the load is connected to the battery and measured only when the voltage is measured. Therefore, the battery replacement timing can be accurately determined. it can.

According to the invention of claim 6 of the present invention,
Since the relay is excited by the MCU at regular time intervals so that the battery voltage can be measured periodically, it is possible to prevent the battery replacement timing from being lost due to a mistaken inspection.

Further, in the invention according to claim 7 of the present invention, the control device is connected to a host computer, and at least the operation time and the unloading frequency of the compressor and the preventive maintenance data of the voltage measurement result of the battery are stored in the host computer. Since it is configured to be managed on the side, it is possible to simplify the management system.

[0028]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention and is a block diagram of a control device.

The control device shown in FIG. 1 has a temperature sensor 1
An interface circuit 3 to which the pressure sensor 2 and the temperature sensor 1 are connected, an interface circuit 4 to which the pressure sensor 2 is connected, and both interface circuits 3 and 4
Analog-to-digital converter (hereinafter referred to as “A
/ D converter ") 5, an MCU 6 mounted in the control device and connected to various devices including the A / D converter 5, a driver 7 and a memory 8 connected to the MCU 6, and a display. Device 9 and the driver 7
Is provided in an electric circuit having a relay 11, 12, 13, 14 connected to the AC power supply 15 and the relay 1
Relay contacts 1 controlled by 1, 12, 13, 14
6, 17, 18, 49. The relay contact 16 has a main motor operation command relay 19 for the compressor.
Is connected to the relay contact 17, and the suction valve 2 of the compressor is connected to the relay contact 17.
1, a blower valve 22 of the compressor is connected to the relay contact 18, and a battery voltage detection circuit 10 is connected to the relay contact 49.

Thus, in the control device shown in FIG. 1, M
The CU 6 connects the relays 11, 12 and 1 via the driver 7.
3 is excited, and the main motor operation command relay 19 of the compressor, the suction valve 21 and the blow valve 22 of the compressor are operated via the relay contacts 16, 17 and 18. As control data for operating these, the temperature sensor 1 detects the oil supply temperature, the discharge temperature, etc., and the detection result is taken into the MCU 6 via the interface circuit 3 and the A / D converter 5. Further, the discharge pressure and the like are detected by the pressure sensor 2,
It is taken into the MCU 6 via the interface circuit 4 and the A / D converter 5. Then, the MCU 6 stores the operating time of the main motor and the number of operations (unloading number) of the blowoff valve 22 in the memory 8, and further subtracts from the preset maintenance time and maintenance frequency, and displays the remaining time until inspection. It is displayed on the container 9. Further, the MCU 6 outputs a warning when the remaining time until inspection becomes zero.

When the MCU 6 measures the voltage of the memory 8 memory battery during a power failure in the memory 8, the relay 14 is excited via the driver 7 and, after a certain period of time, the voltage detection circuit 10 is operated by the relay contact 49. , This voltage detection circuit 10
The voltage of the battery is measured by, the measurement result is stored in the memory 8, and is further taken into the MCU 6 via the A / D converter 5. If the measured voltage is smaller than the specified value, the MCU 6 causes the display 9 to indicate that the battery needs to be replaced.

Next, FIG. 2 is a system diagram of an air system and a capacity control device of a screw compressor when the present invention is applied to the screw compressor.

The screw compressor shown in FIG. 2 has a compressor body 20, an air suction line having a suction port 33, a suction filter 28, and a suction valve 21 and connected to the suction side of the compressor body 20. An air consumption line 35 having a check valve 32, an aftercooler 31, and an air storage tank 30 and connected to the discharge side of the compressor body 20, and a check valve 3 of the air consumption line 35.
2, an effusion line branched from the upstream side of 2, and having an effusion valve 22, an effusion siren 29, and an effluent port 34;
Hydraulic pump 26, four-way solenoid valve 25, hydraulic cylinder 23
A servo mechanism having a piston rod 24 inserted therein and driving the intake valve 21 and the blowoff valve 22, and an MCU 6 mounted on the control device. Temperature sensors 1 are provided on the compressed air inlet side of the oil storage tank 27 and the aftercooler 31, respectively, and each temperature sensor 1 includes an interface circuit 3 and an A / D converter 5 shown in FIG.
It is connected to the MCU 6 via (not shown in FIG. 2). A pressure sensor 2 is provided on the compressed air inlet side of the air storage tank 30, and the pressure sensor 2 passes through an interface circuit 4 and an A / D converter 5 (not shown in FIG. 2) shown in FIG. And is connected to the MCU 6. Also, MC
Data is sent to U6 from various devices, and MC
Commands are issued from U6 to various devices.

In the screw compressor shown in FIG. 2, in the full load operation state, the air sucked from the suction port 33 passes through the suction filter 28 and the suction valve 21 in the fully opened state and enters the compressor body 20. Next, the high-temperature and high-pressure compressed air compressed by the compressor body 20 is sent to the aftercooler 31 through the check valve 32, cooled by the aftercooler 31, and then sent to the air storage tank 30. The compressed air stored in the air storage tank 30 is supplied to the plants through the air consumption line 35 and consumed. In this state, the blowoff valve 22 is closed. In addition, the four-way solenoid valve 25 is switched to the b position by a command from the MCU 6. Therefore, the piston rod 24 that drives the intake valve 21 and the blow-off valve 22 uses the pressure oil supplied from the oil storage tank 27 to the head chamber side of the hydraulic cylinder 24 through the four-way solenoid valve 25 by the hydraulic pump 26 to cause the intake valve to move. It is pushed in the direction of opening 21 and closing the blowoff valve 22.

When the amount of compressed air discharged from the compressor body 20 is larger than the amount of consumed air, the discharge side pressure rises. The pressure on the discharge side is detected by the pressure sensor 2 and sent to the MCU 6 via the interface circuit and the A / D converter. When the discharge side pressure reaches the preset upper limit value, the MCU 6 issues a command to the four-way solenoid valve 25 to switch the four-way solenoid valve 25 to the a position. As a result, the pressure oil sent from the hydraulic pump 26 is supplied to the rod chamber side of the hydraulic cylinder 23 through the four-way solenoid valve 25, and the pressure oil pushes up the piston rod 24 in FIG.
The piston rod 24 closes the intake valve 21 and opens the blowoff valve 22, so that the compressor body 20 is put into an unloaded state.
In this unloaded condition, the air leaking from the intake valve 21
Blow-off valve 23 and blow-off siren 29 and blow-off port 34
More released to the atmosphere.

In the unloaded state, the compressed air is not supplied from the compressor body 20 to the air storage tank 30, and the compressed air is consumed on the plant side, so that the discharge side pressure is reduced.
The discharge side pressure at that time is also detected by the pressure sensor 2, and the detection result is sent to the MCU 6 through the interface circuit and the A / D converter. In this MCU 6, when the discharge side pressure falls to a preset lower limit value, a command is issued to the four-way solenoid valve 25 to switch the four-way solenoid valve 25 from the a position to the b position. When the four-way solenoid valve 25 is switched to the low position, the intake rod 21 is opened and the blowoff valve 22 is closed by the piston rod 24, and the full load state is restored again.

Next, FIG. 3 is a perspective view showing an embodiment of a mechanism for attaching and detaching the memory and the control device.

In the embodiment shown in FIG. 3, the E / EPROM 81 is used as a memory.

The E / EPROM 81 is mounted on the printed circuit board 82. In addition, this printed circuit board 82
A connector 83 is fixed on the top. On the other hand, a connector 87 and a plurality of spacers 88 are fixed on a printed circuit board 80 of the control device. Each spacer 88 is
It is attached by a set screw 89. In the connector 87 fixed on the printed circuit board 80 of the control device,
The connector 86 is attached. A connector 84 is connected to the connector 86 via a cable 85. The connector 84 is adapted to be attached to the connector 83 fixed on the printed circuit board 82 of the E / EPROM 81.

In order to attach the E / EPROM 81 to the control device, the printed circuit board 82 on which the E / EPROM 81 and the connector 83 are mounted is mounted on a plurality of spacers 88 fixed on the printed circuit board 80 of the control device. Place
The printed circuit board 82 is fixed to the spacer 88 with a set screw 90. In addition, the printed circuit board 80 of the control device
The connector 86 is mounted on the connector 87 fixed on the upper side, and the connector 83 fixed on the printed circuit board 82 of the E / EPROM 81 is mounted on the connector 84 connected to the connector 86 via the cable 85. , Set it in use.

When the control device fails, E / EPR
The set screw 90 of the printed circuit board 82 of the OM 81 is removed, the connector 86 is removed from the connector 87, the connector 84 is removed from the connector 83 if necessary, and the printed circuit board 82 of the E / EPROM 81 is removed from the printed circuit board 80 of the defective control device. Then, EE removed
The printed circuit board 82 of the PROM 81 is placed on the printed circuit board 80 of the new control device which has not failed, and is attached in the same manner as described above, and the set of connectors 83 and 84 and the set of connectors 86 and 87 are mounted again. Set it in use.

E used as a memory in this embodiment
Since the EPROM 81 is a non-volatile memory, the preventive maintenance data such as the operating time of the compressor main motor and the number of unloads can be continuously used even if the control device fails. Also, in this embodiment, E / EPR
The OM 81 can be easily removed from the control device and easily attached to a new control device for use.

Next, FIG. 4 is a perspective view showing another embodiment of the mechanism for attaching and detaching the memory and the control device.

In the embodiment shown in FIG. 4, the IC socket 91 is mounted on the printed circuit board 80 of the control device. An E / EPROM 81 is detachably attached to the IC socket 91.

As a result, according to the embodiment shown in FIG. 4, the E-EPROM 81 can be attached to and removed from the control device more easily.

FIG. 5 is a diagram showing an embodiment of the voltage detection circuit of the data holding battery at the time of power failure.

In the embodiment shown in FIG. 5, when the power supply is normal, the voltage of 5V is divided by the resistors 43 and 44, the transistor 42 is turned on, and the base current of the transistor 41 flows through the resistor 45. The transistor 41 also turns on. Therefore, a voltage of 5V is supplied to the memory 8 via the transistor 41. At the time of a power failure, the voltage of 5V drops to 0V, so that the transistors 41 and 42 are turned off. At this time, the voltage of the battery 48 changes to the diode 4
6 and the resistor 47 to the memory 8.

When measuring the voltage of the battery 48, as described above, the relay 14 is excited by the MCU 6 and the driver 7, the relay contact 49 is turned on, and the resistor 50 corresponding to the load is connected to the battery 48. Further, the battery 48 is connected via a resistor 51 to a voltage follower which is a voltage measuring device composed of an operational amplifier 53 and a resistor 52. The relay contact 49 turns on, and the battery 48 has a resistance 50.
After a certain period of time has passed after the connection of (1), the output of the voltage follower is input to the MCU 6 via the A / D converter 5. When the voltage value measured by the voltage follower is smaller than the specified value, the MCU 6 causes the display 9 to indicate that the battery needs to be replaced.

The voltage of the battery 48 is periodically measured according to a command from the MCU 6. It should be noted that the battery 48 is different from the printed circuit board 80 of the control device shown in FIG.
It is mounted on the printed circuit board 82 of the OM 81. Also,
In the embodiment shown in FIG. 5, a RAM is used as the memory 8.

The voltage measuring circuit 10 of the embodiment shown in FIG.
According to the report, when measuring the voltage of the battery 48, the resistance 5
Since 0 is connected and measured, the consumption of the voltage of the battery 48 can be accurately detected. Furthermore, M
Since the voltage of the battery 48 is periodically measured according to the command from the CU 6, it is possible to prevent the battery replacement time from being lost due to a mistaken inspection.

Next, FIG. 6 is a flowchart of the entire management of the compressor by the management program.

In the management program shown in FIG. 6, voltage measurement of the data holding battery, failure determination of each part of the compressor, operation control, and preventive maintenance of various data are carried out.

FIG. 7 is a flow chart showing the voltage measurement of the data holding battery by the management program.

In the embodiment shown in FIG. 7, the voltage of the battery 48 is measured by the voltage measuring circuit 10 shown in FIG. The process energizes the relay 14 periodically (eg, every 12 hours) by the MCU 6 and the driver 7. As a result, the relay contact 49 is turned on and the battery 4 to be measured
A resistor 50 corresponding to a load is connected to 8. Then, after a lapse of a certain time (for example, 10 seconds), the voltage of the battery 48 becomes constant. When the voltage of the battery 48 becomes constant, the data is stored in the RAM, which is the memory 8, and at the same time,
The voltage follower including the resistor 52 and the operational amplifier 53 measures the voltage, and the measured value is output to the MCU 6 via the A / D converter 5. In the MCU 6, the measured value of the voltage of the battery 48 is compared with the specified value, and if the measured value is, for example, 2 V or more, it is determined to be normal, and the voltage measurement ends. If the measured value is, for example, less than 2V, the MCU 6 determines that there is an abnormality, issues a command to display "battery replacement" on the display 9 shown in FIG. 1, and ends the voltage measurement.

FIG. 8 is a flow chart showing the failure judgment of each part of the compressor by the management program.

In the embodiment shown in FIG. 8, the point where the temperature changes when a failure occurs is targeted.

The failure determination process is performed, for example, in the suction port 33 of the screw compressor shown in FIG. 2, between the discharge port side of the compressor body 20 and the compressed air inlet side of the aftercooler 31, and in the oil storage tank 27. , The temperature sensor 1 is provided respectively, the oil supply temperature, the compressed air discharge temperature, and the air suction temperature are measured, and the measured values are sent to the MCU 6 via the interface circuit 3 and the A / D converter 5 shown in FIG. Output to. The MCU 6 stores them in the memory 8 and at the same time compares them with the oil supply temperature, the discharge temperature and the suction temperature which are respectively set in advance. Then, when the measured value of the oil supply temperature is higher than the set value, the MCU 6 judges that a failure has occurred, displays “Oil temperature high” on the display 9, and causes the compressor body 2
Stop 0. Further, even when the measured value of the discharge temperature of the compressor body 20 is higher than the set value, the MCU 6 determines that a failure has occurred, displays "high discharge temperature" on the display 9, and stops the compressor body 20. Furthermore, even when the temperature on the suction port 33 side, that is, the measured value of the suction temperature is higher than the set value, the MC
U6 determines that a failure has occurred, displays "high suction temperature" on the display 9, and stops the compressor body 20. When the measured values of the oil supply temperature, the discharge temperature, and the suction temperature are lower than the set values, the MCU 6 determines that it is normal, and ends the failure determination operation. This failure determination is performed periodically (for example, 0.5
Every second).

In this embodiment, the failure determination based on the temperature measurement value is not limited to the order of the oil supply temperature, the discharge temperature and the suction temperature, and any of them may be preceded. Further, not limited to the oil supply temperature, the discharge temperature and the suction temperature,
If necessary, the temperature of other places may be measured to monitor the occurrence of failure. Furthermore, as a barometer for failure occurrence, as shown in FIGS. 1 and 2, a pressure measurement value by the pressure sensor 2 may be used, or both temperature and pressure may be used.

Next, FIG. 9 is a flow chart showing the operation control of the compressor by the management program.

The operation control shown in FIG. 9 is, for example, the operation control of the compressor body 20 shown in FIG. In the process of controlling the operation of the compressor body 20, the pressure sensor 2 measures the pressure (tank pressure) in the air storage tank 30, and the measured value is measured by the interface circuit 4 and A / D as shown in FIG.
Output to the MCU 6 via the converter 5. The MCU 6 inputs the tank pressure, compares it with the preset value 1 and, if the measured value of the tank pressure is lower than the preset value 1, performs on-load processing and then sets the preset value 2 (however , Set value 1 <set value 2). When the measured value of the tank pressure is higher than the set value 1, the on-road processing is passed and the tank pressure is compared with the set value 2. The measured value of the tank pressure is compared with the set value 2, and when the tank pressure is higher than the set value 2, the unload process is performed and the unload count stored in the E / EPROM, which is a non-volatile memory, is updated. Further, the main motor operating time stored in the E / EPROM is also updated. When the measured value of the tank pressure is lower than the set value 2, a step of passing the unloading process and the updating process of the unloading frequency in the E / EPROM to update the main motor operating time stored in the E / EPROM. Move to. Then, E ・ EPRO
After updating the operation time of the main motor stored in M, the operation control operation is terminated. Then, this operation control is performed periodically (for example, every hour).

The unloading process is performed as follows in the screw compressor shown in FIG. 2, for example. That is, when the compressor discharge amount becomes larger than the consumed air amount, the air storage tank 30
The pressure inside rises. When this pressure is detected by the pressure sensor 2 and the pressure in the air storage tank 30 becomes higher than the set value 2, the MCU 6 issues a command to the four-way solenoid valve 25 to move the four-way solenoid valve 25 from the a position to the b position. Switch to. As a result, pressure oil is supplied to the rod chamber side of the hydraulic cylinder 23,
The piston rod 24 is moved up in FIG. 2, and the intake valve 21 is closed and the blowoff valve 22 is opened by the piston rod 24. As a result, the compressor body 20 is put into an unloaded state.

When compressed air is consumed in the unloaded state, the pressure in the air storage tank 30 drops. When the pressure drops to the set value, the MCU 6 reactivates the four-way solenoid valve 25.
Is issued to switch the four-way solenoid valve 25 from the position b to the position a. As a result, pressure oil is supplied to the head chamber side of the hydraulic cylinder 23, the piston rod 24 is lowered in FIG. 2, the suction valve 21 is opened, the blowoff valve 22 is closed, and the compressor main body 20 is completely restored. Shift to load operation.

The unload speed and the main motor operating time stored in the E / EPROM are used as data for preventive maintenance of the compressor.

Further, FIG. 10 is a flow chart showing preventive maintenance of the compressor by the management program.

The process of preventive maintenance of the compressor shown in FIG. 10 is based on the compressor delivery date stored in the E-EPROM, the current date and time, and the elapsed time after delivery. Is calculated. Then, it is determined whether the elapsed time after delivery is, for example, two years or more. If the elapsed time after delivery is less than 2 years, the operating time of the main motor is read from the E / EPROM. Then, it is determined whether the operation time of the main motor is, for example, 16000 hours or more. As a result of the judgment, when the operation time of the main motor is 16000 hours or more, the MCU 6 displays “Main body inspection” on the display 9 at the shorter time of 2 years after the delivery of the compressor or 16000 hours of the operation of the main motor. Is displayed. When the operation time of the main motor is less than 16000 hours, it is determined whether the elapsed time after delivery of the compressor is one year or more. As a result of the determination, when the elapsed time after delivery is less than one year, it is determined whether the operation time of the main motor is, for example, 8000 hours or more. As a result of the judgment, when the operation time of the main electric motor is 8000 hours or more, the MCU 6 is used for one year after the delivery of the compressor or 8000 hours operation of the main electric motor, whichever is shorter.
Causes the display 9 to display "Auxiliary equipment inspection". Also, when the operation time of the main motor is 8000 hours or more, the MCU
6 causes the display 9 to display "grease supply". Next, when the operation time of the main motor is less than 8000 hours, E
-Read the unload count from EPROM. Then,
The number of unloads is a preset number, for example, 30
It is judged whether or not it is 00 times or more. If the result of the determination is that the number of unloads is 3000 or more, the MCU 6 causes the display 9 to display “Inspection of four-way solenoid valve”. If the number of times of unloading is less than 3000, the preventive maintenance operation is ended.

The above-described management for preventive maintenance is executed periodically (for example, every 12 hours). This makes it possible to thoroughly manage the compressor.

Further, in the present invention, the control device is connected to the host computer, the operating time of the compressor and the unloading frequency,
The host computer manages preventive maintenance data such as battery voltage measurement results. This makes it possible to simplify the management system.

[0069]

According to the invention described in claim 1 of the present invention described above, at least a memory for storing the operating time of the compressor body and the number of times of unloading is removably attached to and detached from the control device. Even if the control unit fails, the preventive maintenance data collected up to that time is used by the control unit after replacement, so that the inspection time of the compressor body can be accurately determined. The effect is that you can know.

According to the second aspect of the present invention, an E / EPROM is used as the memory, and the E / EPR is used.
The OM is mounted on a printed circuit board different from the control device, and the printed circuit board and the control device are connected by a connector. Further, in the invention according to claim 3, the E / EPROM is an IC.
In the invention according to claim 4, the RAM is used as the memory, and the RAM is mounted in the socket.
And the battery for data retention at the time of power failure is mounted on a printed circuit board different from the control device, and the printed circuit board and the control device are connected by a connector. There is an effect that the stored memory can be easily removed from the failed control device and easily attached to a new non-failed control device for use.

According to the invention of claim 5 of the present invention, when measuring the voltage of the data holding battery at the time of power failure, a relay excited by the MCU and a resistance corresponding to a load connected to the battery by the relay, It is configured to include a voltage measuring device that measures the voltage value of the battery and outputs the measured value to the MCU, and only when measuring the voltage, connect a resistance corresponding to the load to the battery and measure. Therefore, there is an effect that the battery replacement timing can be accurately determined.

According to the invention of claim 6 of the present invention, since the relay is excited by the MCU at regular time intervals and the voltage of the battery can be measured periodically, it is possible to overlook the inspection. This has the effect of preventing the battery replacement period from being lost.

According to a seventh aspect of the present invention, the control device is connected to a host computer, and at least the operating time and the unloading frequency of the compressor and the preventive maintenance data of the battery voltage measurement result. Since it is configured to be managed by the host computer side, there is an effect that the management system can be simplified.

[Brief description of drawings]

FIG. 1 is a block diagram of a control device according to an embodiment of the present invention.

FIG. 2 is a system diagram of an air system and a capacity control device of a screw compressor as an example of an air compressor to which the present invention is applied.

FIG. 3 is a perspective view showing an embodiment of a memory used in the present invention and a mechanism for attaching and detaching the memory and the control device.

FIG. 4 is a perspective view showing another embodiment of a mechanism for attaching and detaching a memory and a control device.

FIG. 5 is a diagram showing an embodiment of a voltage detection circuit for a data holding battery at the time of power failure.

FIG. 6 is a flowchart of the entire management of the compressor by the management program.

FIG. 7 is a flowchart showing voltage measurement of a data holding battery by a management program.

FIG. 8 is a flowchart showing a failure determination of each part of the compressor by a management program.

FIG. 9 is a flowchart showing operation control of a compressor by a management program.

FIG. 10 is a flowchart showing preventive maintenance of a compressor by a management program.

[Explanation of symbols]

1 ... Temperature sensor, 2 ... Pressure sensor, 3, 4 ... Interface circuit, 5 ... A / D converter, 6 ... MCU, 7 ... Driver, 8 ... Memory (RAM), 9 ... Indicator, 10 ... Battery Voltage detection circuits, 11-14 ... Relays, 16-18 ... Relay contacts, 19 ... Compressor main motor operation command relays, 2
0 ... Compressor body, 21 ... Suction valve, 22 ... Blow-off valve, 23 ...
Hydraulic cylinder, 24 ... Piston rod, 25 ... Four-way solenoid valve, 26 ... Hydraulic pump, 27 ... Oil tank, 30 ... Air tank,
31 ... Aftercooler, 33 ... Suction port, 34 ... Blow-off port, 3
5 ... Air consumption line, 41, 42 ... Transistors of voltage detection circuit, 43-45 ... Resistor, 46 ... Diode, 47
... resistance, 48 ... battery for data retention, 49 ... relay contact,
50 to 52 ... Resistor, 53 ... Operational amplifier, 80 ... Printed circuit board of control device, 81 ... E / EPROM as memory,
82 ... Printed circuit board for memory, 83, 84, 86, 8
7 ... Connector, 88 ... Spacer, 91 ... E / EPROM
IC socket for use.

Claims (7)

[Claims] 1. A control device for storing at least the operating time and the number of times of unloading of the compressor in a memory and displaying an inspection time, the memory being removably attached to the control device, and the stored data even if removed from the control device. A control device for an air compressor, characterized in that it is configured to hold the. 2. An electrically erasable read-only memory is used as the memory, the memory is mounted on a printed circuit board different from the control device, and the printed circuit board and the control device are connected by a connector. The control device for the air compressor according to claim 1. 3. The control device for an air compressor according to claim 2, wherein the electrically erasable read-only memory is mounted in an IC socket. 4. A random access memory is used as the memory, the memory and a battery for holding data at the time of power failure are mounted on a printed circuit board different from the control device, and the printed circuit board and the control device are connected by a connector. The control device for an air compressor according to any one of claims 1 to 3, characterized in that: 5. An air compressor having a memory protected by a battery for controlling each part by a micro control unit mounted on a compressor control device and storing the control data of the compressor even in the case of a power failure. In the control device of the machine, at the time of measuring the voltage of the battery, the relay excited by the micro control unit, the resistance corresponding to the load connected to the battery by this relay, and the voltage value of the battery are measured, and the measured value is measured by the micro controller. An air compressor control device comprising: a voltage measuring device for outputting to a control unit. 6. The control device for an air compressor according to claim 5, wherein the micro-control unit excites the relay at regular time intervals to periodically measure the battery voltage. 7. The control device is connected to a host computer,
The host computer manages at least the operating time of the compressor, the number of times of unloading, and the preventive maintenance data of the battery voltage measurement result.
6. The control device for the air compressor according to any one of 6.