JPS62178788A - Compressor drive control device - Google Patents

Abstract

PURPOSE:To permit an abnormal condition of a compressor to be detected at its early stage and proper control of the drive thereof, by deciding the abnormal condition by detecting and comparing a driving condition and a pulsating pressure condition of the compressor and turning off an electromagnetic clutch after the condition decided as abnormal has continued for a prescribed time and keeping the condition. CONSTITUTION:When a slip is caused and a pulsating pressure output from a compressor 1 is suspended in a moment, an adding value S8 is delayed for a prescribed period of time by a delay unit 41 and it is issued as a delay signal S9. Then, the delay signal S9 is compared (42) with a reference voltage 43. When it exceeds a prescribed slip ratio, a decision signal S10 for deciding an abnormal condition of the compressor 1 is issued. When the decision signal S10 becomes a level to decide the abnormal condition even once, the condition is kept (44) thereafter until an air conditioning switch 48 is tuned off and a relay signal S12 is output to an air conditioning relay 47 so that the relay 47 is deenergized to turn off an electromagnetic clutch 5. As a result, the compressor 1 is stopped and the abnormal condition of the compressor 1 is checked at its early stage to be properly treated.

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) -i. 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 early 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. This state is II! If ME is used, the disc and pulley may burn out, or the belt may 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 as described above, it becomes impossible to drive the generator or the 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 as disclosed in Japanese Patent No. 200691 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 ■
- Prevents the heald 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 in detail the above-mentioned slip detection, the engine rotation speed is detected based on the ignition-outside signal, and the compressor rotation speed is determined by pulsed armature rotation of the electromagnetic clutch using a Hall element or a generator coil. It is converted into a 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 only when slip occurs is it determined to be abnormal. Therefore, even if the pressure inside the compressor drops and the air conditioning function is no longer satisfied due to, for example, a vane failure or a gas leak from an air conditioning pipe, there is a problem in that the compressor continues to be driven unnecessarily.

Therefore, in order to solve this problem, the applicant of the present invention has previously proposed a "compressor drive control device" (see the patent filed 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 detect disturbances in the regularity of the pulsation pressure relative 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 pressure is abnormal in 'Fr1a' and the electromagnetic clutch is disengaged.

(Problems to be Solved by the Invention) However, even with the device according to the prior application, there are problems with slippage and simple disconnection (OFF) of the electromagnetic clutch.
From the perspective of control, there seems to be room for improvement in the following points.

(1) There is a risk that an abnormality determination may be made in response to normal sudden acceleration, sudden deceleration, and slippage. In addition, when the compressor starts up, the vane protrudes and becomes unstable (chattering).
, there is a risk that the pulse pressure rate will be insufficient and an abnormality determination will be made even though there is no slip.

(II) Since the electromagnetic clutch is simply turned off when the ratio is below a predetermined value, for example, if a phenomenon occurs in which, after slipping once, the drive becomes normal and then slipping occurs two or three times immediately, As the electromagnetic clutch repeats 0N-OFF each time, it is assumed that it may not be possible to catch the compressor abnormality at an early stage and take appropriate measures, which may result in a major failure. be.

(I The electromagnetic clutch may not be able to be turned off even if a slip occurs because it is likely to be affected by disturbances (noise) from other sources such as noise, etc., and it is expected that the detection of the pulse pressure number may lack accuracy.

(Objective of the Invention) Therefore, the present invention determines an abnormality by comparing the driving state and the pulse pressure state of the compressor, turns off the electromagnetic clutch after the abnormality judgment state continues for a certain period of time, and turns off the electromagnetic clutch.
It is an object of the present invention to provide a drive control device for a compressor that can accurately detect an abnormality in a compressor at an early stage and appropriately control its drive by maintaining the state.

(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; Irregularities in the operation of the compressor are detected based on the state and the pulse pressure state of the discharged working medium in the compressor, and when the irregularity is detected, an output is sent when the irregularity continues for a predetermined time or more. Discrimination means d
The output of the determining means d is compared with a predetermined determination reference value to determine whether there is an abnormality in the compressor, and when an abnormality is determined, the operation of the power transmission means a is stopped, and this stopped state is maintained until a predetermined time. and holding means e for holding.

(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.

Then, when the abnormality determination state continues for a certain period of time, the electromagnetic clutch is turned OFF and the OFF state is maintained. Therefore, abnormalities in the compressor can be accurately detected at an early stage, and its drive can be appropriately controlled to avoid development into a major failure.

(Example) Embodiments of the present invention will be described below based on the drawings.

2 to 8 are diagrams showing embodiments of the present invention.

First, the configuration will be explained. In FIG. 2, reference numeral 1 denotes a vane-type rotary compressor (hereinafter simply referred to as a compressor) of an automobile air conditioner. The driving force is received by a pulley 4 and rotated via an electromagnetic clutch (power transmission means) 5, and this driving force is further transferred to an alternator 7 (or a vane pump for power steering) via a V-belt 6. communicated.

The compressor l is a boot IJ4 as shown in detail in Figure 3.4.
A rotor 9 is fixed to the other end of the drive shaft 8. Rotor 9 is housing 10
The rotor 9 includes a plurality of vanes 1.
1 is slidably fitted in the radial direction. As the rotor 9 rotates, each vane 11 sucks a working medium (hereinafter referred to as refrigerant) into the working chamber I2 defined by the housing 10 and each vane 11 from the suction port 13 as shown by the arrow in the figure. , after being compressed to a predetermined pressure, the discharge valve 14
It is discharged to the outside via.

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

Referring again to FIG. 2, 20 is a control unit, to which the pulse pressure signal Sp from the pulse pressure sensor 15 is input, and furthermore, the ignition from the igniter (driving state detection means) 21 of the engine 2 is input. A signal Si is input as data corresponding to the engine speed. Since 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, the number of pulses of the ignition signal Si represents the engine rotation speed.

The control unit 20 has the functions of a determining means and a holding means, and determines whether or not there is an abnormality regarding the compression m1 based on the above-mentioned human power information, and controls the drive of the compressor 1.

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

The impedance conversion unit 31 performs impedance matching between the pulse pressure signal Sp and the control unit 20, and the low-pass filter 32 removes unnecessary noise components and converts the fundamental component S of the pulse pressure signal Sp. Extract. A
The C amplifying section 33 uses this basic component S.

The waveform shaping section 34 AC amplifies the AC amplified signal S.
2 into a rectangular wave S, and the differentiator 36 shapes the rectangular wave S.
3 is shaped into a negative direction pulse waveform 33' and then differentiated, and a differential wave S4 corresponding to the pulse pressure cycle is output to the calculation section 40. The DC offset section 35 supplies a predetermined DC offset voltage of to each of the sections 32 to 34,
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 S having a usable level, and the waveform shaping section 38 shapes the converted signal S into a rectangular wave S6.

The integrating section 39 integrates the rectangular wave S6 and outputs an integrated wave S7 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 S7 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 a disturbance in the regularity of the pulse pressure number, and becomes judgment data for determining an abnormality of the compressor 1. When the above-mentioned disturbance of regularity occurs, the delay section 41 delays the addition value Sll by a certain period of time after the occurrence, and outputs the delayed addition value Sll to the comparison section 42 as a delayed signal S9.

The comparator 42 compares the delay signal S, with the reference voltage 4 from the reference unit 43, and determines whether the slip ratio is less than or equal to a predetermined slip ratio (pulse pressure number/engine rotation speed), and outputs a determination signal S,. Output. When the determination signal S10 exceeds the predetermined slip ratio even once and reaches a level at which it is determined that the compressor I is abnormal, the holding section 44 holds that state until the power of the drive control device is turned off, and maintains the holding signal S10. Output.

When the holding signal S11 is input, the relay drive output section 45 outputs a relay signal S+Z having a predetermined voltage level to the air conditioner relay 47. When the relay signal S+Z is not input, the air conditioner relay 47 closes its normally open contact 47a by the voltage applied between the electromagnetic coil 47a, allowing the electromagnetic clutch 5 to be energized, and the relay signal SI□ is input. When the voltage difference between and the electromagnetic coil 47a disappears, the excitation is released and the normally open contact 47a is opened, and the electromagnetic coil 5a of the electromagnetic clutch 5 is closed.
The electromagnetic clutch 5 is turned off. The stabilized power supply section 46 supplies the operating voltage Vcc to each section of the circuit after performing delay processing to prevent malfunction due to mechanical chattering of the air conditioner switch 48.

The air conditioner switch 48 is a switch that controls the operation of an air conditioner (air conditioner). Specifically, it is expressed in a general form including an air conditioner thermo switch, a low pressure switch, and a high pressure switch, and controls the operation of the control unit 20 by the operation of 0N10FF.

Next, the operation will be explained with reference to the timing charts shown in FIGS. 5 to 7.

When the air conditioner switch 48 is turned on, power is supplied to each part of the circuit of the control unit 20, and the air conditioner relay 4 is turned on.
7 is energized, the electromagnetic clutch 5 is turned on, and the compressor 1 receives the driving force from the engine 2 and rotates.

When the compressor 1 is normal, the five vanes 11 generate pressure changes in the refrigerant gas (ie, pulsation pressure) five times per rotation. This pulse pressure is detected by the pulse pressure sensor 15 and input to the control unit 20 as a pulse pressure signal sp. Then, as shown in FIG. It corresponds to the pressure period.

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 (1). This integral wave S7 corresponds to the period of the ignition pulse. The average voltage of each of the signals S 4 and S 7 is calculated by the calculation unit 40, and both are added and outputted as an added value S.

Here, if we pay attention to the characteristics of the above-mentioned average voltage, the signal S4 is determined by the number of revolutions (pulsation pressure number) of the compressor 1 as shown in FIG. 6 (al).
The average voltage increases as . On the other hand, as shown in the same figure (C1), the average voltage of the signal S decreases as the rotation speed of the engine 2 increases.In other words, each signal s, , S? They have a mutually contradictory relationship, and normally maintain a value of 1/2 of the circuit operating voltage Vcc.

In this case, if 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 Sll also decreases accordingly. Further, in a case where the pulse pressure output is lost, 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 S also decreases rapidly. Therefore, as shown in FIG. 6(b), the presence or absence of slip or pulsation pressure output, that is, an abnormality in the early stage of the compressor 1, can be determined based on how much the level of the addition value S8 has decreased from %Vcc. I can do it. Although the judgment of such early abnormalities is different in the apparatus related to the earlier application mentioned above,
This embodiment is similar to the present embodiment in that it is based on pulse pressure output. 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 belt 3 or the electromagnetic clutch 5, but instantaneous slips often occur due to sudden acceleration or deceleration even during normal compressor operation. In addition, even immediately after the compressor 1 is driven, there is a risk that a momentary no-output state of the pulse pressure output may occur due to the occurrence of slip, the unstable state of the internal pressure of the air conditioning piping, or the transient response characteristics of the vane 11 in the compressor 1. .

In such a case, if an abnormality determination is made every time a slip occurs, problem (1) of the prior application will occur, which is not preferable.

Therefore, in this embodiment, when a slip occurs, the delay section 41
From that point on, the added value S is delayed for a certain period of time and output as a delayed signal S9 (see FIG. 6 +dl). Thereafter, as shown in FIG. 7(a), the delay signal S, is compared with the reference voltage VR, and if it exceeds a predetermined slip ratio, the compressor l
A determination signal S1° for determining an abnormality is output. Once the determination signal S1° reaches a level at which it is determined that an abnormality has occurred, this state will be maintained until the air conditioner switch 48 is turned off, and a relay signal S1□ will be output to the air conditioner relay 47 to relay 4
7 is de-energized, the electromagnetic clutch 5 is turned off, and the driving of the compressor 1 is stopped, thereby avoiding development of a major failure (see FIGS. 7(b) to 7(e)). In addition, Fig. 7 m, (
gl is the characteristic and operating voltage Vc of the air conditioner switch 48
c. Further, V in each figure indicates the battery voltage.

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

Regarding (1), since abnormality determination is not performed immediately every time there is a slip, abnormality is appropriately determined and only true slips are accurately detected.

Regarding (II), when a true slip is detected even once, the electromagnetic clutch 5 is immediately turned OFF, and this OFF state continues until the air conditioner switch 48 is turned OFF and the operation of the drive control device itself is stopped.

Therefore, it is possible to prevent the electromagnetic clutch 5 from being repeatedly turned on and off (and to take appropriate measures by keeping the compression a1 at its initial stage).

Regarding (III), since the pulse pressure signal Sp and ignition signal Si are appropriately waveform-processed and the levels of both are adjusted, it is difficult to be affected by noise, and the pulse pressure number can be detected with high precision. It can be carried out.

FIG. 8 is a circuit example in which the control unit 20 shown in FIG. 2 is realized using specific circuit elements.

In the figure, R1-R26 are resistance elements, 01-C13 are capacitors, ICI-IC4 are IC circuit elements, D1-D7 are diodes, zD1-ZD5 are Zener diodes, TRI
~TR4 indicates a transistor.

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.

It should be noted that the functions of the control unit 20 can also be performed by a microcomputer and realized using specific rough hardware. 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.
It is possible to avoid major breakdowns in IT equipment, improve performance, stability, and maintainability, and also make the equipment more compact and reduce costs.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a basic conceptual diagram of the present invention, FIGS. 2 to 8 are diagrams showing an embodiment of a compressor drive control device according to the present invention, and FIG. 2 is a diagram showing the entire structure. Fig. 3 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, and Fig. 6 is a diagram showing signal waveforms of each part. FIG. 7 is a diagram showing the signal waveforms of each part, and FIG. 8 is a specific circuit diagram of the control unit. ■... Compressor, 2... Engine, 5... Electromagnetic clutch (power transmission means), 15.
...Pulse pressure sensor (pulse pressure state detection means), 20...
...Control unit (discrimination means, holding means)
, 21...Igniter (driving state detection 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) detecting irregularities in the operation of 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; , a determining means that sends an output when the irregularity is detected and continues for a predetermined period of time; and e) determining an abnormality of the compressor by comparing the output of the determining means with a predetermined criterion value. A drive control device for a compressor, comprising: holding means that stops the operation of the power transmission means when an abnormality is determined and maintains this stopped state until a predetermined time.