JPS62174585A - Device for controlling drive of compressor - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a failure due to the restarting of a compressor which has been stopped because of abnormality by judging the abnormality of said compressor from its driving condition and the pulsating pressure condition of a discharging medium while stopping the operation of a power transmitting means until a restoring measure has been taken. CONSTITUTION:A signal for indicting the driving condition of a compressor is inputted from a driving condition detecting means (b), which uses the pulse voltage of the igniter of an engine as its output signal, to a judging means (d). And, a signal for indicating the pulsating pressure condition of a discharging medium is inputted from a pulsating pressure condition detecting means (c) consisting of a pulsating pressure sensor provided on a discharge side into the judging means (d). Since the relation between both signals is always constant and only varies when there is abnormality in the compressor, it such a variation has occurred, an abnormality detecting signal is inputted from the judging means (d) to a memory means (e), and stored in it. The abnormality detecting signal is held by a holding means (f) to keep the operation of a power transmitting means (a) stopped until the memory of the abnormality signal is erased by a signal from a restoration means (h).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for controlling the drive of a vane-type rotary compressor to which driving force is transmitted from a rotary drive source via a clutch or the like.

(Prior Art) Generally, a compressor does not have its own rotational power, but receives power from another rotational drive source to rotate and compress a predetermined working medium. In such compressors, it is desirable to detect malfunctions at an early stage and take appropriate measures.

As an example, focusing on a compressor for an automobile air conditioner, this compressor operates a compression mechanism by receiving driving force transmitted from an engine, which is a rotational drive source, via a V-belt using an electromagnetic clutch. In this case, for example, if the rotor of the compression mechanism seizes and locks, the disk on the compressor side of the electromagnetic clutch and the pulley on the engine side may slip, or the V-belt may slip. If this condition continues, the disc and pulley will eventually seize or the belt will break.

Depending on the type of car, the above-mentioned pulley is configured as a double pulley, and the driving force for the generator or the pump for the power steering system is obtained through this. If the disk and pulley seize, it will no longer be possible to drive the generator or pump for the power steering system, and in extreme cases, there is a risk that the vehicle will be unable to drive.

Therefore, in order to eliminate this problem,
A device such as that disclosed in Publication No. 20.0691 has been proposed.

This device compares the engine rotation speed and the compressor rotation speed, and detects when the compressor rotation speed is lower than the engine rotation speed by a predetermined value due to the seizure of the rotor of the compression mechanism described above. , determines that a slip has occurred and turns off the electromagnetic clutch (cutting off the transmission of driving force from the engine to the compressor) to prevent the slip, seizure, and V
- Prevents the belt from slipping or breaking. This results in
This prevents the occurrence of a situation in which the driving force of the generator or power steering device cannot be obtained as described above.

Here, to explain the slip detection in more detail, the engine rotation speed is detected based on the ignition-outside signal, and the compressor rotation speed is determined by detecting the amateur rotation of the electromagnetic clutch using a Hall element or a generator coil. The pulse signal is converted into a pulse signal and detected. Then, it is determined whether a slip has occurred by comparing both signals.

For this reason, for example, in detecting the rotational speed of a compressor, a magnet is attached to the armature, and a bracket for fixing a Hall element or a power generation coil is required on the detection side. Therefore, when replacing the belt, etc., the number of man-hours required for attaching and assembling the same bracket increases, resulting in inefficiency. Also,
The cost increases due to the increase in the number of parts to be installed. Incidentally, the bracket is merely a metal fitting for attaching a detection element such as a Hall element or a power generating coil, and is essentially unnecessary when driving the compressor.

Also, according to this amateur rotation detection method,
It is not possible to detect the pressure inside the compressor, and an abnormality is determined only when slip occurs. Therefore, for example, there is a problem that the compressor continues to be driven unnecessarily even if the air conditioning function is not satisfied due to a drop in the pressure inside the compressor due to a defective vane protrusion, a gas leak from the air conditioning piping, etc.

Therefore, in order to solve this problem, the applicant of the present invention has previously proposed a "compressor drive control device" (see the patent issued on December 10, 1985).

This device uses a pulsation pressure sensor to detect the pulsation pressure of the working medium discharged from the working chamber of the compressor, and compares this with the engine rotation speed to determine if the pulsation pressure is irregular with respect to the engine rotation speed. When this occurs (specifically, when the ratio of both is less than a predetermined value), it is determined that the compressor is abnormal and the electromagnetic clutch is disengaged.

(Problems to be Solved by the Invention) However, even with the device according to the prior application, there is room for improvement in the following points from the perspective of simple OFF control of the electromagnetic clutch. Conceivable.

(1) Since the configuration simply performs OFF control of the electromagnetic clutch when the above ratio is below a predetermined value, for example, after slipping once, it becomes normal drive and then immediately twice.
If the phenomenon of slipping occurs three times, the electromagnetic clutch will repeat 0N-OFF each time, and it is assumed that it may not be possible to catch the compressor abnormality at an early stage and take appropriate measures. This may result in a major failure. In addition, when the device is powered off, this OFF control command is cleared, and the next time it is restarted, it will start up in an abnormal state, and then the above
An FF control command is issued. Therefore, there is a risk that a secondary failure or an initial failure due to re-driving in an abnormal state may develop into a serious failure.

(II) In the event of an abnormality, the electromagnetic clutch is turned OFF and the operation of the compressor is simply stopped, so the driver may not notice this as soon as possible and may not be able to take prompt action against the abnormality.

(Purpose of the Invention) Therefore, the present invention determines an abnormality based on the driving state and the pulsating pressure state of the compressor, and turns the electromagnetic clutch into the
While setting it to FF and maintaining its OFF state,
Furthermore, when an abnormality is determined, this is memorized and an alarm is issued, and this abnormality record is cleared when a prescribed recovery action is taken, thereby accurately detecting a compressor abnormality at an early stage and controlling its drive. It is an object of the present invention to provide a compressor drive control device that can appropriately control the compressor and avoid development of secondary failure due to re-driving.

(Means for Solving the Problems) In order to achieve the above object, the compressor drive control device according to the present invention transmits the driving force of a rotary drive source to the compressor, as shown in FIG. a driving state detecting means for detecting the driving state of the rotary driving source; a pulsating pressure state detecting means C for detecting the state of the pulsating pressure of the working medium discharged from the compressor; A determination means d determines whether there is an abnormality in the compressor based on the state and the pulsation pressure state of the discharged working medium in the compressor, and a determination means d stores the abnormal state of the compressor based on the output of the determination means d, and determines whether the compressor is abnormal or not. a storage means e that clears the memory of this abnormal state when a predetermined recovery action is taken; holding means f for holding the compressor until a predetermined time, alarm means g for issuing an alarm based on the output of the storage means e as necessary, and detecting that a predetermined recovery action has been taken for an abnormality in the compressor. It is equipped with recovery detection means.

(Operation) In the present invention, the driving state of the engine and the pulsating pressure state of the compressor are compared to determine an abnormality.

When an abnormality is determined, this is memorized and an alarm is issued, and the electromagnetic clutch is turned OFF.
State is preserved. Moreover, the above-mentioned abnormality memory is cleared when recovery measures are taken for the compressor.

Therefore, an abnormality in the compressor can be accurately detected at an early stage, its drive can be appropriately controlled, and development of secondary failure due to re-driving can be avoided.

(Example) Hereinafter, the present invention will be explained based on the drawings.

2 to 8 are diagrams showing one embodiment of the present invention.

First, the configuration will be explained. In Fig. 2, ■ is a vane-type rotary compressor (hereinafter simply referred to as a compressor) for an automobile air conditioner, and compression JR, 1 is an engine (rotary drive source) 2.
The pulley 4 receives the rotational driving force transmitted from the V-belt 3 and rotates through the electromagnetic clutch (power transmission means) 5. Furthermore, this driving force is transmitted to the alternator 7 (or power (It may be a vane pump for steering).

As shown in detail in FIG. 3.4, the compressor 1 has a drive shaft 8 connected to a pulley 4, and a rotor 9 is fixed to the other end of the drive shaft 8. The rotor 9 is rotatably housed in a housing 10, and includes a plurality of vanes 11.
is slidably fitted in the radial direction. As the rotor 9 rotates, each vane 11 sucks a working medium (hereinafter referred to as refrigerant) from a suction boat 13 into a working chamber 12 defined by the housing 10 and each vane 11 as shown by the arrow in the figure. After being compressed to a predetermined pressure, it is discharged to the outside via the discharge valve 14.

A pulse pressure sensor (pulse pressure state detection means) 15 is attached to the housing 10 near the discharge valve I4, and the pulse pressure sensor 15 has a ceramic piezoelectric element that is sensitive to pressure. The pulsation pressure sensor 15 detects pressure fluctuations (pulsation pressure) acting on the piezoelectric element when refrigerant is discharged from the discharge valve 14 by the heater 11, converts this into a voltage pulse, and generates a pulsation pressure signal Sp. Output. The pulses of the pulse pressure signal Sp represent the number of pulse pressures of the refrigerant in the compressor 1.

Again in FIG. 2, reference numeral 20 denotes a control unit. The control unit 20 receives the pulse pressure signal Sp from the pulse pressure sensor 15 manually, and also receives ignition from the igniter (driving state detection means) 21 of the engine 2. A signal Si is input as data corresponding to the engine speed. The primary current of the ignition coil in the igniter 21 is switched on and off in synchronization with the engine rotation, and is supplied to the engine 2 via the distributor 22, so the number of pulses of the ignition signal Si represents the engine rotation speed.

The control unit 20 has functions as a determination means, a storage means, and a holding means, and determines whether or not there is an abnormality regarding the compressor 1 based on the input information, controls the drive of the compressor 1, and outputs an alarm signal. do.

That is, the control unit 20 has an impedance i
conversion section 31, low-pass filter 32, AC amplification section 33, waveform shaping section 34, DC offset section 35, differentiation section 36, level conversion section 37, waveform shaping section 38, integration section 39, calculation section 40, delay section 41, comparison section part 42, reference part 43, holding part 4
4, relay drive output section 45, storage section 46, recovery section 47,
It is composed of an alarm output section 48 and a stabilized power supply section 49.

The impedance conversion unit 31 performs impedance matching between the pulse pressure signal Sp and the control unit 20.
The low-pass filter 32 removes unnecessary noise components and extracts the fundamental component S of the pulse pressure signal Sp. The AC amplifying section 33 AC amplifies this fundamental component Sl, and the waveform shaping section 34 shapes the AC amplified signal S2 into a rectangular wave S.
Further, the differentiator 36 converts the rectangular wave S into a negative direction pulse waveform S,
/ and then differentiated and outputs a differential wave S4 corresponding to the pulse pressure cycle to the calculation unit 40. Note that the DC offset section 35 supplies a predetermined DC offset voltage VOf to each of the sections 32 to 34, and this offset voltage V.

f is for improving filter characteristics, AC amplification characteristics, and waveform shaping characteristics.

On the other hand, the level conversion section 37 converts the ignition signal Si into a signal S5 having a usable level, and the waveform shaping section 38 shapes the converted signal S into a rectangular wave S.

The integrating section 39 integrates the rectangular wave S6 and outputs an integrated wave S corresponding to the period of the ignition pulse to the calculating section 40.

The calculation unit 40 calculates the average voltage of each of the differential wave S4 from the differentiating unit 36 and the integral wave S from the integrating unit 39, and calculates the sum S8 by adding these average voltages together.
Output. This added value S8 appears as a level change due to disturbance in the regularity of the pulse pressure number, and becomes judgment data for determining an abnormality of the compressor I. When the above-mentioned disturbance of regularity occurs, the delay section 41 delays the addition value S8 by a certain period of time after the occurrence, and outputs the delayed addition value S8 to the comparison section 42 as a delayed signal S.

The comparator 42 compares the delay signal S, with the reference voltage (A) from the reference unit 43, and determines whether or not the delay signal S is equal to or less than a predetermined slip ratio (pulse pressure number/engine rotation speed). Output. When the determination signal S1° exceeds the predetermined slip ratio even once and reaches a level at which it is determined that the compressor l is abnormal, the holding unit 44 holds this state until the power of the drive control device is turned off, and outputs the holding signal Sl+. Output.

On the other hand, the determination signal S1° is input to the storage unit 46,
A recovery signal S1□ is further input to the storage unit 46 from the recovery unit 47. The recovery unit 47 detects this signal S based on the recovery detection signal Sll from the recovery switch (recovery detection means) 50.
When I3 changes from ON level to OFF level, it is outputted as the recovery signal S1□. The recovery switch 50 is provided at a predetermined position in the vehicle, and when an abnormality in the compression a1 is stored in the storage unit 46, the driver takes a predetermined recovery action for the abnormality (for example, repairing the abnormal part) and the driver When the switch body is operated by , the recovery detection signal 5Iff is output from the ON level to the OFF level.

The storage unit 46 stores the determination signal S. is at a level at which it is determined that the compressor 1 is abnormal, the abnormality determination level (i.e., abnormal state) is not recorded until the recovery signal S1□ is input,
The alarm signal S14 is outputted to the alarm output section 48, and the abnormality signal S15 is outputted to the relay drive output section 45. Note that this processing is performed when the air conditioner switch 53 is turned ON (described later).
10FF (i.e. 0N10 of the power supply in this device)
FF), and depends solely on the operation of changing the recovery switch 50 from ON to OFF at least once.

When the holding signal S I 1 is input, the relay drive output unit 45 outputs a relay signal SI6 having a predetermined voltage level to the air conditioner relay 51, and also outputs an abnormal signal from the storage unit 46 even when the holding signal S11 is not input. While S15 is being input, the output of the relay signal SI6 is continued m times. When the relay signal SI6 is not input, the air conditioner relay 51 closes the normally open contact 51a by the voltage applied between the electromagnetic coils and allows the electromagnetic clutch 5 to be energized, and when the relay signal SI6 is input, the electromagnetic When the voltage difference between the coils disappears, the excitation is released and the normally open contact 51a is opened, and the energization to the electromagnetic coil 5a of the electromagnetic clutch 5 is stopped and the electromagnetic clutch 5 is turned off.
shall be.

On the other hand, when the alarm output unit 48 receives the alarm signal S14, it outputs an alarm activation signal S17 to the alarm device (alarm means) 52. The alarm device 52 is composed of an alarm lamp or an LED indicator, and when the alarm activation signal SI7 is input, it issues an alarm indicating that the compression ml is in an abnormal state. In addition, the stabilized power supply section 49
After performing delay processing to prevent malfunction due to mechanical chattering of the air conditioner switch 53, the operating voltage Vcc is supplied to each part of the circuit.

The air conditioner switch 53 is a switch that controls the operation of an air conditioner (air conditioner). Specifically, it is expressed in a general form including air conditioner thermo switch, low pressure switch, and high pressure switch, and ON10 F
The operation of the control unit 20 is controlled by the F operation.

Next, the operation will be explained with reference to the timing charts shown in FIGS. 5 to 8.

When the air conditioner switch 53 is turned on, power is supplied to each part of the circuit of the control unit 20, and the air conditioner relay 5
1 is energized, the electromagnetic clutch 5 is turned on, and the compressor 1 receives the driving force from the engine 2 and rotates.

Compression ia1 is 1 by five vanes 11 when it is normal.
The refrigerant gas pressure changes (i.e., pulsating pressure) five times per rotation. This pulse pressure is detected by the pulse pressure sensor 15,
It is input to the control unit 20 as a pulse pressure signal Sp. Then, as shown in FIGS. 5(a) to 5(e), after unnecessary noise components are removed inside the control unit 20, AC amplification, waveform shaping, and further differentiation processing are performed. This differential wave S4 corresponds to the pulse pressure cycle.

On the other hand, the ignition signal Si from the engine 2 is similarly input to the control unit 20, and is subjected to level conversion, waveform shaping, and integration processing as shown in FIGS. 5(f) to 5(i). This integral wave S corresponds to the period of the ignition pulse. Each of the above signals S4 and S7 is supplied to the calculation unit 4.
0, the respective average voltages are calculated, and both are added and output as an added value S8.

Here, focusing on the characteristics of the average voltage, the signal S4 is the rotation speed (pulsation pressure number) of the compressor 1 as shown in FIG. 6(a).
The average voltage increases as . On the other hand, the average voltage of the signal S decreases as the rotational speed of the engine 2 increases, as shown in FIG. That is, the signals S4 and S7 have a mutually contradictory relationship with respect to increases and decreases in the number of rotations, and normally maintain a value of 1/2 of the circuit operating voltage Vcc.

In this case, when the pulse pressure rate decreases due to an abnormality in the compressor 1, only the average voltage of the signal S4 decreases, and the added value S8 also decreases. In addition, when the pulse pressure output becomes zero, the pulse pressure number is detected as zero, and the average voltage of the signal S4 rapidly decreases to OV. Therefore, the voltage of the added value S8 also decreases rapidly. (Accordingly, as shown in Fig. 6 fbl, depending on how much the level of the added value S has fallen from '/zVc (), the presence or absence of slip or pulsation pressure output, that is, abnormality in the early stage of the compressor l, can be determined. Judgment can be made.

It should be noted that although the manner of determination of such early abnormality is different in the apparatus according to the earlier application described above, it is similar in that it is based on the pulse pressure output as in the present embodiment. However, this embodiment differs from the previous application in the manner of determination, and is different in that consideration is given to facilitating subsequent drive control.

Incidentally, the actual slip state is caused by the slip of the V-belt 3 or the electromagnetic clutch 5, but instantaneous slips often occur due to sudden acceleration or deceleration even during normal compressor operation. Further, immediately after the compressor 1 is driven, there is a possibility that slip occurs, the internal pressure of the air conditioning pipe becomes unstable, or the pulse pressure output becomes momentarily ineffective due to the transient response characteristics of the vanes 11 in the compressor 1.

In such a case, if an abnormality determination is made every time a slip occurs, the following situation may occur, which is undesirable.

That is, there is a possibility that an abnormality determination may be made in response to slippage during normal sudden acceleration or sudden deceleration. In addition, in an unstable state (chattering) of vane protrusion when the compressor is started, there is a risk that the pulse pressure number will be insufficient and an abnormality determination will be made even though there is no slippage.

Therefore, in this embodiment, when a slip occurs, the delay section 41
From that point on, the added value s[l is delayed for a certain period of time and output as a delayed signal S9 (see FIG. 6(d)). Thereafter, as shown in FIG. 7(a), the delay signal S is compared with the reference voltage VR, and when it exceeds a predetermined slip ratio, a determination signal SIO for determining whether the compressor 1 is abnormal is output. Once the determination signal SIO reaches a level that determines an abnormality, the air conditioner switch 53 will be turned off from then on.
The relay signal SI6 is output to the air conditioner relay 51, the air conditioner relay 51 is deenergized, and the electromagnetic clutch 5 is turned off.
The driving of the compressor 1 is stopped and development of a major failure is avoided (see FIGS. 7 fb to 7 e)). In addition, Fig. 7 (f
) and (g) show the characteristics and operating voltage Vcc of the air conditioner switch 53. Further, in each figure, ``8'' indicates the battery voltage.

Furthermore, when the comparison section 42 determines that the compressor 1 is abnormal and the determination signal SIO reaches the abnormality determination level, this is stored in the storage section 46 . The memory of this abnormal state is retained until the recovery switch 50 is operated regardless of whether the device power is turned off, and a warning is issued to the driver through a visual display.

8(a) to (bl) show a series of timing charts of the above-mentioned operations from the operation of the air conditioner switch 53 to the operation of the electromagnetic clutch 5. As is clear from the figure, there is an abnormality in the compressor 1. At times, the electromagnetic clutch 5 is maintained in the OFF state regardless of whether the air conditioner switch 53 is turned OFF.

Based on the above, a comparison with the device related to the prior application will be considered.

Regarding (1), when a true slip is detected even once, the electromagnetic clutch 5 is immediately turned OFF, and from then on, this OFF state is maintained by the air conditioner switch 53. 'mVc is applied by the FF until the operation of the drive control device stops. Further, the abnormal state of the compressor 1 due to a true slip is recorded tα, and this recorded tI\ state is maintained until the recovery switch 50 is operated.

Therefore, the QN of the electromagnetic clutch 5 is
- OFF is not repeated (and abnormalities in the compressor 1 can be suppressed to the initial stage and appropriate measures can be taken.

Regarding (II), the driver can immediately take appropriate recovery measures by displaying a warning in the event of an abnormality, and the development of a serious malfunction can be suppressed.

Note that the warning is not limited to visual display; for example, auditory recognition using audio (buzzer, etc.) may be used, or both may be used in combination.

FIG. 9 is a circuit example in which the control unit 20 shown in FIG. 2 is realized using specific circuit elements.

In the figure, R1-R29 are resistive elements, C1-C13 are capacitors, ICI-IC4 are rc circuit elements, Di-D9 are diodes, ZDI-ZD6 are Zener diodes, and TRI
~TR5 indicates a transistor SSR is a keep type relay. A prototype of this device has already been completed using such a circuit example, and the size is extremely compact. Its performance and effectiveness have also been confirmed through in-house testing.

Note that the functions of the control unit 20 can also be performed by a microcomputer and realized by specific software. Rather, it would be convenient if the same control was performed in conjunction with the electronic control of the engine.

(Effects) According to the present invention, it is possible to accurately detect an abnormality in a compressor at an early stage and to appropriately control its drive. Recovery measures can be taken. As a result, it is possible to prevent the compressor from developing into a major failure.

[Brief explanation of drawings]

FIG. 1 is a basic conceptual diagram of the present invention, FIGS. 2 to 9 are diagrams showing an embodiment of a compressor drive control device according to the present invention, FIG. 2 is an overall configuration diagram thereof, and FIG. FIG. 4 is a schematic sectional view of the compressor, FIG. 4 is a schematic side view of the compressor, FIG. 5 is a diagram showing signal waveforms of each part, FIG. 6 is a diagram showing signal waveforms of each part, and FIG. FIG. 8 is a diagram showing the signal waveforms of each part, and FIG. 9 is a specific circuit diagram of the control unit. 1...Compressor, 2...Engine, 5...Electromagnetic clutch (power transmission means), 15.
...Pulse pressure sensor (pulse pressure state detection means), 20...
...Control unit (judgment means, storage means,
holding means), 21...igniter (driving state detection means), 5
0...Recovery switch (recovery detection means), 52.
...Alarm device (alarm means).

Claims (1)

[Claims] a) power transmission means for transmitting the driving force of the rotary drive source to the compressor; b) drive state detection means for detecting the drive state of the rotary drive source; c) discharge working medium of the compressor. d) determining means for determining an abnormality in the compressor based on the driving state of the rotary drive source and the pulsating pressure state of the working medium discharged in the compressor; e) ) storing an abnormal state of the compressor based on the output of the determining means, and clearing the memory of the abnormal state when a predetermined recovery action is taken for the abnormality of the compressor; a holding means that stops the operation of the power transmission means when an abnormality of the machine is stored and maintains this stopped state until a predetermined time; and g) an alarm means that issues an alarm based on the output of the storage means as necessary. A drive control device for a compressor, comprising: (h) recovery detection means for detecting that a predetermined recovery action has been taken in response to an abnormality in the compressor.