JPH0227162Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a protection device for an air conditioning compressor, and more particularly to a device for protecting a bearing portion of the compressor by driving the compressor for a short time when the compressor is in use.

The compressor that makes up the air conditioner for vehicles is hardly driven during low temperature periods such as winter, so the balls that make up the bearing are in a stationary state.
In this state, due to the vibration of the car, the balls and the races that hold the balls wear out and become dented or chipped, or abrasion particles are interposed between the balls, which increases the load when the bearing rotates, causing a large load on the compressor. In the past, there was a risk that the compressor would seize up or make abnormal noises.

Therefore, conventional methods have been proposed in which the compressor is driven for a short time when the ignition switch is turned on when the compressor is not in use, or the compressor is driven every certain distance traveled by the vehicle. Since the compressor is always driven when the ignition switch is turned on or before the vehicle has traveled a certain distance, the compressor has to be driven many times, which is disadvantageous in terms of power saving. Furthermore, in the case of a vehicle in which the compressor is driven before a certain period of travel, the compressor is driven inadvertently, which increases the load on the engine and makes it difficult to accelerate, for example.

The purpose of this invention is to make the compressor ready to drive when lubricating oil such as grease or fuel is injected into the engine, and after this injection is completed, the compressor is driven for a short time when the engine starts, thereby eliminating the above drawbacks. This will be explained in detail below using examples.

FIG. 1 is a circuit diagram showing an embodiment of the protection device for an air conditioning compressor according to the present invention. and resistance 2
The connection point with is connected to the non-inverting input side of the comparator 3. A connection point between resistors 4 and 5 is connected to the inverting input side of comparator 3. The output of comparator 3 is the output voltage of sensor 1 when the outside temperature is below the set level.
When Vr becomes larger than the reference value Vo, it is inverted from L level to H level. This output is supplied to one input side of the AND circuit 6. 7 is a detector that detects the injection of grease o-mat, and this is turned on in conjunction with, for example, when the grease o-mat injection operation stick installed on the driver's seat side is operated to inject grease o-mat; is grounded, and the other end is connected via a resistor 8 to a connection point between a resistor 9 and a capacitor 10, which are connected in series with each other.
This connection point is supplied to the other input terminal of the AND circuit 6 via a waveform shaping circuit 11, a timer circuit 12 consisting of a monostable circuit, etc. The output of the AND circuit 6 is supplied to the base side of a transistor 15 via a resistor 14. Contact 16 on the transistor 15 side
A is connected to the relay 16 that controls the contact 1.
6a is connected in series to an electromagnetic clutch 19 which transmits the torque of a pulley 17 rotated by the engine to a compressor 18. The transistor 15 is controlled by a compressor control device 20, which is cooled by the compressor 18. The compressor is controlled by turning on and off the transistor 15 based on output signals from a sensor that detects the temperature on the evaporator side, a temperature sensor inside the vehicle, a temperature setting device, and the like. Specifically, when the temperature on the surface side of the evaporator falls to a set level, the compressor 18 is turned off, and the set level at which the compressor is turned off is controlled to gradually increase as the set temperature of the temperature setting device increases, for example. However, the operation rate of the compressor 18 is reduced in a region where the set temperature is high, thereby saving power.

The operation of the air conditioning compressor protection device having the above configuration will be explained. First, when the outside temperature is low, such as in winter, Vr>Vo, so the output of the comparator 3 becomes H level as shown in FIG. 2a. When grease is injected here, the detector 7 that detects this injection turns on and off, and the capacitor 10 discharges and charges the charge, so a pulse is generated from the output side of the capacitor 10, and this pulse is shown in Fig. 2b. The timer circuit 12 is operated by this pulse _P1 , and the timer circuit 12 outputs a pulse _P2 shown in FIG. 2c, which corresponds to the time width T of this pulse _P2 . During this time, the output of the AND circuit 6 becomes H level. For this reason, transistor 15 turns on and relay 1
6 is energized, the contact 16a is turned on, the electromagnetic clutch 19 is energized, and the compressor 18 is set to be drivable for a set time T. For example, the drivable state is set for a relatively long time T, on the order of several tens of minutes. Next, when the grease o-mat is injected and the injection work is completed and the engine is started before the set time T elapses, the compressor 18 is driven until the set time T elapses, so the bearing of the compressor is This allows the bearings to rotate, and prevents wear and tear on the balls and races due to the bearing balls not moving. According to the present invention, the grease o-mat is injected about once every few weeks under normal operating conditions, so the compressor can be driven an appropriate number of times, reducing the power loss caused by frequently driving the compressor 18 as in the past. In addition to preventing the compressor from being operated carelessly, the compressor does not become difficult to operate.

In this embodiment, the compressor is driven by detecting the injection of grease or lubricating oil, but the present invention is not limited to this.
For example, when fuel is injected into the fuel tank, this may be detected and the compressor may be set in a state where it can be driven for a short period of time, for example, for several minutes, so that when the engine is started after fuel is injected, the compressor is activated. Can be driven. in this case,
As the fuel injection detector, a switch may be provided which is linked to the attachment/detachment of a cap that opens and closes the fuel injection port, and fuel injection may be detected based on a signal from this switch.

As explained above, the air conditioning compressor protection device according to the present invention includes a detection means for detecting the injection of lubricating oil or fuel, and a drive means for energizing the electromagnetic clutch of the compressor based on the output signal from the detection means. and a timer means for keeping the energization time at the set time, so that the compressor can be driven when lubricating oil or fuel is injected, and when the engine is started after lubricating oil or fuel has been injected. Since the compressor can be driven for a short period of time, it is possible to protect the bearings that make up the compressor's bearing, and since the number of times the compressor is driven can be set to an appropriate value, it is possible to protect the bearings while saving power. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of an air conditioning compressor protection device according to the present invention, and FIGS. 2 a to 2 c are waveform diagrams for explaining the operation of the device. DESCRIPTION OF SYMBOLS 1...Outside temperature sensor, 7...Grease o-mat injection detector, 15...Transistor, 18...Compressor, 19...Electromagnetic clutch.

Claims (1)

[Scope of utility model registration request] The compressor comprises a detection means for detecting lubricating oil injection or fuel injection into the vehicle, a drive means for energizing the electromagnetic clutch of the compressor based on a signal from the detection means, and a timer means for maintaining the energization time for a set time. A protection device for an air conditioning compressor, characterized in that the drive means is configured to keep the compressor in a driveable state for a time set by the timer means when lubricating oil or fuel is injected.