JPS6215366B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an air conditioner for an automobile, depending on the engine condition such as the load applied to the engine.
The present invention relates to a device for controlling the rotation of a compressor for compressing refrigerant.

Conventionally, in air conditioners for automobiles, the compressor is connected to the driving engine, and its rotation speed is changed in accordance with changes in engine rotation speed, such as acceleration, deceleration, rotation speed, etc. There is no compressor drive control.

Therefore, during acceleration, the engine load is large and the compressor load is further added, so there is a drawback that the increase in vehicle speed is slowed down.

In addition, increases and decreases in the number of revolutions have a large effect on the performance of the compressor, and at high revolutions it becomes over-operated, and at low revolutions it has the defect of rapidly decreasing its cooling capacity. However, when decelerating using engine braking, there is no defect as mentioned above, and it is better to use the surplus capacity, and it will not increase fuel consumption.
It also has the advantage of enhancing the effect of engine braking.

Therefore, this invention detects acceleration from the negative pressure in the intake pipe of the engine, stops the drive of the compressor during acceleration, and switches the drive of the compressor to high rotation speed during engine braking.
The capacity of the compressor is increased using the surplus power, and the compressor is switched between multiple stages depending on the engine speed.
The aim is to reduce the effect of applying no load to the compressor during acceleration, and to reduce the influence of changes in compressor speed by switching to multiple stages depending on the engine speed except during acceleration, thereby reducing changes in compressor capacity. It is something to do.

An embodiment of the present invention shown in the drawings will be described below.

In FIG. 1, two pulleys 3 and 4 are provided on an output shaft 2 of a driving engine 1, and one pulley 3 is fixed to the output shaft 2. The other pulley 4 is rotatably provided on the output shaft 2 and is connected to the output shaft 2 by an electromagnetic clutch 5.

The compressor 6 is provided with two pulleys 8 and 9 on its drive shaft 7, and one pulley 8 is attached to the drive shaft 7.
The drive shaft 7 is connected to the drive shaft 7 by an electromagnetic clutch 10. The other pulley 9 is fixed to the drive shaft 7.

Endless belts 11 and 12 are stretched between the above-mentioned pulleys 4 and 9 and between pulleys 3 and 8, and the power is transmitted from the pulleys 3 and 4 to the pulleys 8 and 9 via the belts 11 and 12. . Since the pulley ratio of pulleys 3 and 8 is larger than that of pulleys 4 and 9,
When the electromagnetic clutch 5 is energized, the compressor 6
rotates at a low speed, and when the electromagnetic clutch 10 is energized, the rotation changes to a high speed.

In FIG. 2, an embodiment of the invention is shown.

The load detector 13 detects the negative pressure (pressure) in the intake pipe of the engine, and a known device is used.
It is detected as a voltage value proportional to the engine intake pipe negative pressure.

The rotation speed detector 14 detects the rotation speed of the engine, and detects the voltage value proportional to the rotation speed. The intake pipe negative pressure detected by the load detector 13 is compared with a reference value determined by resistors 16 and 17 by a comparator 15. In this comparator 15, when the intake pipe negative pressure is in a low state, that is, when the intake pipe negative pressure is considerably low (close to positive pressure) PB ₁ such as during acceleration, as shown in FIG. The output from the device 15 is inverted from its previous state (high level) and becomes low level. Therefore, since a low level 0 is applied to one input of the AND circuits 18 and 19, both electromagnetic clutches 5 and 10 are de-energized and the compressor 6 stops driving.

When normal driving returns from acceleration driving, the engine intake pipe negative pressure becomes greater than PB ₁ , and therefore the output from the comparator 15 becomes a high level, and one input of the AND circuits 18 and 19 receives a high level 1. is now applied.

In this case, the rotation of the compressor 6 is controlled based on the engine rotation speed detected by a rotation speed detector 14, which will be described below.

The rotation speed detected by the rotation speed detector 14 is determined by the resistance 2.
Set rotation speed determined from 0, 21 and comparator 22
are compared. In this comparator 22, the engine speed is compared with, for example, a set rotation speed (2000rpn).
Below 2000 rotations, the output of the comparator 22 is at a low level, and the input of the AND circuit 18 is at a low level of 0.
is applied, and at the same time, an inverted high level 1 is applied to the other input of the AND circuit 19 via the inverter 23.

Therefore, the AND circuits 18 and 19 have a high level 1.
Under the condition that the pressure is high (the negative pressure is greater than _PB1 ), the output from the AND circuit 19 becomes high level 1, the electromagnetic clutch 10 is excited, and the compressor 6 rotates at high speed.

When the engine speed is higher than 2000 rpn, the output of the comparator 22 becomes a high level, and the AND circuit 19
The output of the AND circuit 18 becomes a low level and the output of the AND circuit 18 becomes a high level. Therefore, the electromagnetic clutch 5 is energized and the compressor 6 rotates at a low speed. Deceleration due to engine braking is detected by the intake pipe negative pressure, and when the intake pipe negative pressure reaches a fairly high value (PB ₂ shown in Figure 4), engine braking is detected, and at that time, the rotation of the compressor The engine rotates at high speed without being affected by engine speed.

That is, the negative pressure value detected by the negative pressure detector 13 is compared with the reference value determined by the resistors 24 and 25 by the comparator 26, and when the negative pressure reaches a state PB ₂ where the negative pressure is considerably high, such as during engine braking, The output from comparator 26 is inverted from its previous state (high level) and becomes low level. Therefore, the AND circuit 27 becomes a low level 0, which is inverted by the inverter 23 and becomes a high level 1, which is input to the AND circuit 19. Since a high level 1 is input to this AND circuit 19 except during acceleration, the output of the AND circuit 19 becomes high level, the electromagnetic clutch 10 is excited, and the compressor 6 is switched to high speed rotation. It is something.

A flowchart of this embodiment is shown in FIG. 3. According to this flowchart,
An example of the operation of this invention will be briefly described.

When the air conditioner is activated, the negative pressure in the engine intake pipe and the engine speed are detected.
Whether the engine is accelerating or not is judged from the negative pressure, if it is accelerating, that is, PB is greater than ₁ ;
If the compressor is turned off and it is determined that it is not present during acceleration, the _next step is to determine whether or not the negative pressure is quite high. The compressor is operated at high speed. In cases other than during engine braking, in the next step, the engine speed is set to, for example, 2000 rpm.
It is determined whether the rotation speed is higher or lower, and if the rotation speed is higher than that, the compressor rotates at a low speed, and if it is lower than that, the compressor is rotated at a high speed.

In this way, since the compressor rotates at high speed during engine braking, the surplus capacity during engine braking can be used to increase air conditioning capacity, and it also contributes to improving the effectiveness of engine braking. be.

The control of high speed or low speed of the compressor based on the above-mentioned negative pressure (pressure) and rotational speed (RPN) appears as a characteristic line as shown in FIG.

In this embodiment, the rotation of the compressor is switched to two stages, but the rotation is not limited to this and may be switched to a plurality of three stages.

As mentioned above, this invention eliminates the load on the compressor when accelerating, and when decelerating due to engine braking, the compressor rotates at high speed to increase air conditioning capacity with surplus power. Since the system switches between low speed and high speed stages depending on the engine speed, it is possible to maintain the compressor speed at an appropriate speed and reduce fluctuations.
It is possible to save power and improve the durability of the compressor.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of the connected state of the engine and compressor, FIG. 2 is a circuit diagram of an embodiment of the present invention,
FIG. 3 is a flow chart similar to the above, and FIG. 4 is a characteristic diagram of the present invention. 1...Engine, 6...Compressor, 5, 10...
Electromagnetic clutch, 13... Negative pressure detector, 14... Engine speed detector.

Claims (1)

[Claims] 1. In an automotive air conditioning system that is driven by a driving engine and capable of controlling the rotation speed of a multi-stage compressor, the negative pressure in the engine intake pipe is detected by a negative pressure detector, and the engine rotation speed is detected by a negative pressure detector. is detected by a rotation speed detector, and when the engine intake pipe negative pressure during acceleration is on the considerably low side, the compressor drive is stopped, and when the engine intake pipe negative pressure is on the considerably high side during engine braking, the compressor drive is stopped. is switched to a high rotation side, and when the negative pressure in the engine intake pipe does not meet both of the above conditions, the rotation speed of the compressor is switched in multiple stages depending on the engine rotation speed. A method for controlling the rotation speed of a compressor in an automotive air conditioner.