JPS5970895A - Device for detecting abnormalities in vane rotary compressor - Google Patents

Abstract

PURPOSE:To enable abnormalities such as seizure in a compressor to be securely detected by providing an electrode in a position close to a rotor of a side plate on the same plane as the side plate to detect a period of time in which the side plate keeps contacting the rotor or vane. CONSTITUTION:When a compressor starts to be run, a rotor 3 and a vane 2 always rotate in a cylinder 1 without contacting the front side plate 4 since a proper gap 6 is formed between them and said plate 4. When the gap 6 between the front side plate 4 and the rotor 3 cannot be maintained by any causes, the rotor 3 is urged against one or both of the front and rear side plates 4, 5 to be rotated. In this case, the rotor 3 produces seizure on both side plates to bring about the locked condition eventually. Then ON signals showing complete contact are taken out continuously from an electrode 7 for a long time to stop current supply to an electromagnetic clutch for relaying drive of the compressor by a control circuit and thereby the running of the compressor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a vane rotary compressor, which detects abnormalities in a safety device that stops compressor operation when an abnormality occurs in the compressor and the compressor is no longer able to operate normally. This invention relates to a detection device.

Conventional structure and its problems In the past, rotary vane compressors used in vehicle air conditioning systems generally obtained driving force solely from the engine via a V-belt, etc., but recently In response to demands for lighter vehicles, lower costs, and smaller engine compartments, a belt-driven structure has been adopted that is combined with other auxiliary equipment such as an alternator and power steering hydraulic pump.

Therefore, in the case of a compressor abnormality, especially a locking phenomenon, a function is required to turn off not only the refrigeration cycle but also the electromagnetic clutch of the compression wheel for the safety of the vehicle, and various structures have been adopted.

For example, in a practical example, a pickup sensor consisting of a permanent magnet and a coil is placed opposite the rotating shaft of a compressor or the armature part of an electromagnetic clutch, and a metal piece provided on the rotating side or a notch is used to Therefore, there is a method of extracting the compressor rotation speed as a pulse by utilizing the change in the magnetic field of the pickup sensor.

This is due to the high cost of 1. the pip sensor and the machining of the rotating shaft, for example. 2. Sensor life and reliability are limited under high temperature and high vibration conditions. 3. It has drawbacks such as the need for a circuit for comparing and calculating the rotational speed of the compressor and the engine.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and aims to ensure that abnormalities such as burning in the compressor can be detected.

Structure of the Invention In order to achieve this object, the present invention provides an electrode on the side plate of a vane rotary compressor at a position close to the rotor and on the same plane as the side plate, and detects the time period during which the vane remains in contact with the rotor. The rotor and ■[This is to judge the firing rate of one plate.

With this configuration, it is possible to detect seizure of the compressor section or eccentric wear of the shaft section.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to accompanying drawings.

In the figure, the vane rotary compressor includes a cylindrical cylinder 1, a plurality of retractable vanes 2, and a rotor 3 that is eccentrically arranged so that a part thereof is close to the cylinder 1. a front side plate 4 that closes 1 from both sides;
The front side plate 4 is equipped with a compression section consisting of a rear side plate 6.
An electrode 6 is installed so that its tip is flush with the front plate 4 at a location close to the rotor 3, and this electrode 6 is electrically insulated from its surroundings.

In the above configuration, when the compressor starts operating, there is a certain appropriate gap between the rotor 3 and the front plate 4! 6, the rotor 3 rotates within the cylinder 1 without constant contact. The vane 2, which is still retractable in the rotor 3, slides while being pressed against the inner wall of the cylinder 1, but the rotor 3
Similarly, there is a gap 6 between the side plate 4°5 and there is no constant contact.

However, the rotor 3 and the vane 2 do not maintain the clearance 6 all the time, but move instantaneously so that the clearance 6 disappears.

That is, the rotor 3 or the base 72 may come into metal contact with the front plate 4. At this time, the electrode 6 provided on the front plate 4
From this, an irregular pulse-like waveform as shown in A in FIG. 2 is extracted as a signal.

Next, if for some reason the gap 6 between the front plate 4 and the rotor 3 cannot be maintained, the rotor 3 is pressed against one or both of the front plate 4 and the rear plate 5 and rotates. In this case, the rotor 3 causes seizure on both side plates, and finally becomes locked. At this time, the signal of the electrode 5 becomes the state shown in B in FIG. 2, and the ON signal indicating complete contact continues for a long time.

FIG. 3 shows a flowchart from detecting burnout to stopping the compressor.

The signal from the electrode 6 is input and integrated to form an average voltage. Then, this voltage is compared with the voltage obtained in advance when the rotor 3 is in complete contact.

The difference is then set as the operating voltage of the relay, and when the difference is zero, the relay is activated to stop energizing the electromagnetic clutch that mediates the drive of the compressor.

Thus, when the rotor 3 and the electrodes 6 are in continuous contact for a certain period of time or more, the compressor stops operating.

This control circuit can be easily constructed using a control circuit including a well-known microcomputer, so illustration and description thereof will be omitted.

Effects of the Invention As is clear from the above embodiments, the abnormality detection device for a vane rotary compressor of the present invention detects the time when the vane continuously contacts the electrode provided on the same plane as the side plate. This eliminates the need for a pick-up sensor consisting of a permanent magnet and electromagnetic coil and a computation circuit for comparison with the engine rotation speed to determine seizure on the side plate of the rotor, resulting in low-cost, simple, and highly reliable abnormality detection. It can also detect abnormal conditions such as eccentric wear on the rotor shaft.

[Brief explanation of drawings]

Fig. 1 is a sectional view of main parts of a vane rotary compressor equipped with an abnormality detection unit of the present invention, Fig. 2 is a diagram of output waveforms from electrodes in the abnormality detection unit, and Fig. 3 is a compression diagram in the abnormality detection device. FIG. 3 is a flow diagram showing the operation of an electric circuit for machine protection. 2... Vane, 3... Rotor, 4...
...Front side plate, 6...Electrode, 6...Gap. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (1)

[Claims] A vane rotary compressor includes a cylinder having a cylindrical inner wall, a rotor having a plurality of movable vanes, and a compression chamber formed by side plates that close the cylinder from both sides, and further includes a portion of the side plate adjacent to the rotor. An abnormality detection device for a vane rotary compressor, which is insulated from the outside and provided with an electrode so that its tip is on the same plane as the side plate.