JP6944797B2 - Fluid machine - Google Patents

Description

The present invention relates to a fluid machine that compresses or expands.

The compressor of Patent Document 1 diagnoses a failure of the compressor by vibration, and stops the compressor when it is determined to be a failure. At this time, the presence or absence of failure of the failure diagnosis device is also diagnosed, and if the failure diagnosis device fails, the user can release the stop with the operation switch.

Japanese Unexamined Patent Publication No. 2006-97654

The notification regarding the compressor abnormality excluding the failure of the failure diagnosis device of Patent Document 1 is a notification that a failure that is premised on repair has occurred. Therefore, the compressor is stopped for a long period of time because repairs are arranged after the failure occurs. Of course, if you press the operation switch without repairing it, vibration will be detected immediately and it will stop, or a serious failure that requires replacement of the piston or cylinder will occur.

An object of the present invention is to grasp the failure risk at an early stage and enable planned maintenance of a fluid machine.

In order to solve the above problems, the present inventors analyze the vibration data detected by the fluid machine that stops when a large vibration is detected, and there is a high possibility that a failure in which the main body of the fluid machine cannot be driven will occur within a predetermined period. Or, it may take more than the above-mentioned predetermined period until the "precursor vibration immediately before the failure" (for example, the vibration at the level where the piston is damaged and the connecting rod hits the crank chamber) and the failure that the fluid machine cannot be driven occur. It has made it possible to discriminate highly probable "initial precursor vibration" (eg, vibration at a level where damage to internal parts of the compressor body is suspected).

Specifically, the initial precursor vibration can be discriminated by, for example, a vibration of the first threshold value or more and less than the second threshold value, and the precursor vibration immediately before the failure is, for example, a vibration larger than the second threshold value.

However, the user may urgently need to drive a fluid machine. Therefore, until the precursor vibration immediately before the failure is detected, after continuous driving for a predetermined time, the first stop release process (for example, screen operation of the fluid machine or power ON / OFF), which is simpler than the second stop release process described later, is performed. The second stop release process (for example, when the stop can be released by a process that can release the stop) and the precursor vibration immediately before the failure is detected, or when the stop by the initial precursor vibration detection and the first stop release process are performed a predetermined number of times. Stop in a state where the stop can be released with the programmable controller).

According to the present invention, the risk of failure can be grasped at an early stage, and the planned maintenance of the fluid machine becomes possible.

It is a schematic diagram of the product when the abnormality detector in the package type air compressor is mounted. It is a schematic diagram of the product when the abnormality detector in the tank mount type air compressor is mounted. It is an air circuit diagram at the time of the road operation (normal operation) of the air compressor of FIG. 1 and FIG. It is a circuit block diagram of an abnormality detector. It is a flowchart of control of an abnormality detector. This is an example of displaying the board surface of the control board.

Embodiments of the present invention are shown below.

First, the product configuration diagram according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. The air compressor 1 shown in FIGS. 1 and 2 is provided in a part of a compressed fluid supply path arranged in the entire equipment such as a factory.

The air compressor 1 compresses a gas such as air in the compressor main body 2 by driving the electric motor 11. The air compressor 1 is a package type air compressor in which a set of an air compressor or the like is mounted inside the housing in the case of FIG. 1, and a tank mount type air in which a tank 9 and a set of compressors are integrated in the case of FIG. It is a compressor. In this embodiment, both the package type and the tank mount type are applied to a non-lubricated air compressor.

The package-type air compressor 1 of FIG. 1 is a multi-cylinder, reciprocating compressor body 2, a cylinder 3, a storage tank (hereinafter, tank 9), a frame 10, an electric motor 11, an electromagnetic switch 33, and an abnormality detector. It has 44.

The tank mount type air compressor 1 of FIG. 2 includes a multi-cylinder reciprocating compressor main body 2, a cylinder 3, a tank 9, an electric motor 11, an electromagnetic switch 33, and an abnormality detector 44.

Since the functions of each part are general except those described below, the description thereof will be omitted.

FIG. 3 shows an air circuit diagram of the compressors of FIGS. 1 and 2 during load operation (normal operation).

The compressor main body 2 reciprocates the piston 13 in the cylinder 3 by the rotational movement of the crankshaft directly connected to the electric motor 11 which is rotationally driven as a drive unit. Air is sucked from the intake chamber 4 via the suction silencer 7 by the reciprocating movement of the piston 13. The sucked air is compressed in the cylinder 3 (compression chamber), and this is discharged from the discharge chamber 5 as a compressed fluid. In the case of this embodiment, the discharged compressed fluid is stored in the tank 9 provided integrally with the compressor main body 2, but may be directly supplied to a pneumatic device or other storage tank. The stored compressed fluid is supplied to a pneumatic device or the like from a stop valve 8 provided in the tank 9.

The electric motor 11 is connected to an electromagnetic switch 33 and an abnormality detector 44 as control units for controlling the operation of the compressor main body 2 (details of the connection will be described in the circuit configuration diagram of FIG. 4).

The abnormality detector 44 notifies the control board 67 of the abnormal vibration when an abnormality occurs in the compressor main body 2. The control board 67 notifies the user of the notified abnormal vibration alarm or abnormality. When the abnormality detector 44 detects abnormal vibration, the electromagnetic switch 33 is shut off to stop the motor 11 and the compressor main body 2 (details of the abnormality detection flow will be described later using the control flowchart of FIG. 5). The electric motor 11 is connected to the power supply 55 via the electromagnetic switch 33.

FIG. 4 shows a specific circuit configuration example of the abnormality detector 44. The abnormality detector 44 of this embodiment is connected to a piezoelectric element 60 that detects acceleration, an amplification factor adjusting circuit 61, a signal amplifier 62, a filter 63, an envelope detection circuit 64, a switch 66, and a control board 67. The microcomputer 68 and the memory 69 are provided.

The abnormality detector 44 is fixed to the frame and measures the acceleration generated from the compressor main body 2 and passed through the frame 10. The abnormality detector 44 causes abnormal vibration (precursor vibration immediately before failure or initial precursor vibration) when the acceleration of the compressor body 2 itself and the acceleration of the compressor body 2 itself rise abnormally due to an abnormality occurring inside the compressor body 2. ) Is generated, the control board 67 is notified. As shown in FIG. 6, a plurality of notification units of the control board 67 may be displayed depending on the situation, or may be a device that notifies by a sound such as a buzzer.

Since the signal of the piezoelectric element 60 as an acceleration sensor for detecting acceleration is generally a weak signal, the amplification factor is adjusted by the amplification factor adjusting circuit 61 and vibration is performed by using the signal amplifier 62 in order to convert it into a signal that can be handled by a microcomputer or the like. The signal is amplified and transmitted through the filter 63. The signal after passing through the filter 63 is connected to the A / D converter 65 built in the microcomputer 68 via the envelope detection circuit 64 that holds the amplitude signal. The amplification factor may be adjusted at the time of product shipment or by the customer or worker. When the power supply 55 and the electromagnetic switch 33 are energized, the electric motor 11 operates and the compressor main body 2 starts. At that time, the acceleration due to the vibration propagates from the piezoelectric element 60 to the microcomputer 68, and the abnormality detector 44 operates. At this time, the storage circuit 69 updates the abnormality history (occurrence time, acceleration indicating the magnitude of vibration, etc.) assuming that an abnormality has occurred.

FIG. 5 shows a control flowchart of the abnormality detector 44.

After operating the compressor main body 2, when the acceleration measured by the abnormality detector 44 exceeds the first threshold value (in this embodiment, when the internal parts of the compressor main body 2 are suspected to be damaged, the acceleration is 4 g. The level is set to the first threshold value), and the control board 67 outputs an alarm (abnormal output from the second time onward). At this time, if the measured acceleration is less than the second threshold value, the operation of the compressor main body 2 is continued, and the first alarm output is output for a certain period of time (in this embodiment, the duration is set to 30 hours). After the continuation, the electromagnetic switch 33 is shut off, and the operation of the compressor main body 2 is stopped.

When the abnormality detector 44 reaches an acceleration exceeding the second threshold value (in this embodiment, the acceleration is set to 7 g level when the connecting rod of the compressor main body 2 reaches the level of hitting the crank chamber). Even during the notification time of the first abnormal output, the electromagnetic switch 33 is shut off and the operation of the compressor main body 2 is forcibly stopped.

If the detected acceleration value is less than the second threshold value, the stop control can be canceled by turning off the power, but if it is more than the second threshold value, the stop state is stopped by the dedicated programmable controller (hereinafter referred to as "Procon") after maintenance. It was set to be released.

If the detected acceleration value is less than the second threshold value, after restarting the operation of the compressor main body 2, the abnormal (initial alarm) output is continued for a certain period of time (in this embodiment, it is set to 10 hours). After that, the compressor body 2 is stopped again. In this embodiment, the number of times is 3 (alarm: 30 hours, abnormality: 10 hours), but the number of repetitions may be any number of times. The acceleration threshold value shown in FIG. 5 is a tentative value, and may be the same or different for each model. Further, the abnormality detection cycle is a tentative value, and the time may be long or short. The release method using the power switch or the processor computer is an example of the release method, and other methods may be used.

FIG. 6 shows an example of displaying the board surface when the abnormality detector 44 detects an abnormality. The phases are classified into (1) to (4) and "emergency" according to the acceleration value and the operation time after the abnormality is detected, and the abnormality (alarm at the first time) is displayed by AL71, Er72 to 73, Er7E, etc., respectively. .. Further, when the abnormality detector 44 fails or the wiring connecting the abnormality detector 44 and the control board 67 is broken, AL7U is displayed. This board display is a temporary display method, and may have completely different contents or may be the same or different for each model. Further, the described abnormality detection cycle is a tentative value and may be longer or shorter than the time shown in the figure, and the release method using the power switch or the process controller is an example of the release method. Other methods may be used. Further, since it is possible to send a signal to the outside when detecting an abnormality, it is possible to monitor the abnormality of the air compressor 1 even if the person is far away, for example. In addition to the board display, by turning on the maintenance lamp, it is possible to reliably confirm the abnormality.

The acceleration generated by the air compressor 1 is usually a minute acceleration due to a minute vibration according to the rotation speed of the motor 11 or the compressor main body 2. On the other hand, when the drive means is started, the tank pressure and temperature, the load such as the operation mode (normal operation (load operation) / unload operation) fluctuates, the sliding resistance of the air compressor increases, and the air compressor When a mechanical abnormality such as a lock of the driving means occurs due to a loss of function or an abnormality of the connecting mechanism, a larger acceleration than usual occurs. In this case, accelerations having an amplitude and a period different from the above-mentioned normal accelerations are superimposed. In particular, in the case of serious damage such as a mechanical abnormality or a breakage of the connecting rod connecting the piston 13 or the piston 13 and the crankshaft of the motor 11, an acceleration having a particularly large amplitude is periodically observed.

Therefore, in this embodiment, when an abnormality occurs inside the compressor main body 2, when the abnormality detector 44 detects an acceleration equal to or higher than the first threshold value, the control board 67 displays an abnormality (alarm at the first time). When the electric motor 11 (electromagnetic switch 33) of the compressor main body 2 is stopped after a lapse of a predetermined time and an acceleration of a second threshold value or more larger than the first threshold value is detected, the stop control is also performed in the same manner. The abnormality detector 44 starts operation when the compressor main body 2 starts the load operation, and first performs the initial setting of the microcomputer 68. Next, the abnormal history up to now is read from the storage circuit 69, and the abnormal state when the compressor main body 2 operates last time is determined.

If there was an abnormality last time, or if an acceleration exceeding the first threshold value is detected at the present time even if there is no such abnormality, a compressor abnormality display (alarm at the first time) is displayed and stop control is performed after a certain period of time has elapsed. After that, when the acceleration above the second threshold value is detected, or when the detection of the acceleration above the first threshold value and below the second threshold value exceeds a predetermined number of times, a signal is sent from the abnormality detector 44 to the control board 67 to operate the motor. The compressor main body 2 is stopped by setting so that Abnormal display is continued. When it is determined that there is no abnormality, the abnormality history is saved in the storage circuit 69, and this loop is repeated every time the operation is performed.

From the above, according to the present embodiment, since the operation of the compressor main body 2 can be continued from the abnormality display to the operation stop, the customer who has stopped the air supply can grasp the abnormality of the compressor main body 2 at an early stage and compress. It is possible to take measures before the damaged state of the machine body 2 worsens.

The examples described so far are merely examples of embodiment of the present invention, and the technical scope of the present invention is not limitedly interpreted by them. That is, the present invention can be implemented in various forms without departing from the technical idea or its main features. Further, the present invention may be carried out by combining a plurality of examples.

Although the reciprocating motion has been described so far, the present invention is not limited to the reciprocating compressor as long as it is driven by an electric motor and can be operated without load, but other fluids such as a scroll type fluid machine and a screw compressor. It can also be applied to machines.

1 Air compressor 2 Compressor body 3 Cylinder 4 Intake chamber 5 Discharge chamber 7 Suction silencer 8 Stop valve 9 Tank 10 Frame 11 Electric motor 13 Piston 33 Electromagnetic switch 44 Abnormality detector 55 Power supply 60 Piezoelectric element 61 Amplification rate adjustment circuit 62 Signal Amplifier 63 Filter 64 Surrounding line detection circuit 65 A / D converter 66 Switch 67 Control board 68 Microcomputer 69 Storage circuit

Claims (7)

A fluid machine body that compresses or expands fluid,
The drive unit that drives the fluid machine body and
It is equipped with an acceleration sensor that detects the acceleration of vibration of the fluid machine body.
When the acceleration sensor detects acceleration of the first threshold value or more and less than the second threshold value, the drive unit is stopped in the first stop state which can be released by turning off the power after a predetermined time has elapsed.
A fluid machine characterized in that when the acceleration sensor detects an acceleration equal to or higher than the second threshold value, the drive unit is stopped in a second stopped state in which the stop cannot be released even when the power is turned off. In claim 1,
The initial precursor vibration is detected at the first threshold value or more and less than the second threshold value.
A fluid machine characterized in that a precursory vibration immediately before a failure is detected at the second threshold value or higher. In claim 1,
The fluid machine is a reciprocating compressor.
Vibration at a level suspected of damaging internal parts of the compressor body is detected at the first threshold value or more and less than the second threshold value.
A fluid machine characterized in that vibration at a level at which the connecting rod hits the crank chamber is detected at the second threshold value or higher. In claim 1,
When the acceleration of the first threshold value or more and less than the second threshold value is detected, an alarm is notified for the first time, and an abnormality is notified for the second and subsequent times.
A fluid machine characterized in that when an acceleration equal to or higher than the second threshold value is detected, an abnormality is notified . In any of claims 1 to 3,
After the acceleration sensor detects acceleration of the first threshold value or more and less than the second threshold value, and after a predetermined time elapses, the process of stopping the drive unit in the first stop state is repeated a predetermined number of times, and then in the second stop state. A fluid machine characterized by stopping the drive unit. In any of claims 1 to 3,
When the acceleration of the first threshold value or more and less than the second threshold value is detected and then the acceleration of the second threshold value or more is detected, the driving unit is forcibly stopped even before the elapse of a predetermined time. machine. In claim 1,
A fluid machine characterized in that the second stopped state can be released from a stop by a signal from a dedicated controller.

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