JP2545586B2 - Compressor control method for vehicle cooling system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a compressor control method for a vehicle air conditioner,
In particular, the present invention relates to a compressor control method for a vehicle cooling device that drives a compressor via an electromagnetic clutch by a vehicle running engine.

(Prior Art) In a vehicle cooling device in which a vehicle traveling engine drives a compressor of a cooling device via an electromagnetic clutch, when the compressor is coupled to the engine by the electromagnetic clutch when the engine speed is high, In order to prevent the electromagnetic clutch and the like from being subjected to a large impact and lowering their durability, a compressor control method has been conventionally used in which the drive of the compressor is stopped when the engine speed is equal to or higher than a predetermined speed. It is more known (for example, JP-A-56-128219).

(Problems to be Solved by the Invention) When the above-described conventional control method is applied to an automatic vehicle, the predetermined number of revolutions is constant irrespective of the gear shift range of the transmission, and there is the following problem.

For example, when traveling on an uphill road, the gear shift range (shift range) of the transmission is not set to the normal drive range (for example, the range in which the shift gear position is automatically changed in the range of 1st speed to 4th speed) and is set to the low speed range. (For example, the transmission gear position is 1st speed ~
Often, the vehicle is set to a range in which automatic gear shifting is performed in the third speed range or a range fixed to the second speed), and the vehicle speed is relatively slow, but the engine speed is high for a long time. . On the other hand, the predetermined rotation speed is set to a high rotation speed value of 6,000 rpm, for example, for the purpose of stopping the driving of the compressor of the cooling device when the engine rotation speed is very high, and therefore, as described above. Even in the running state, the engine speed rarely exceeds the predetermined speed, and therefore the compressor continues to be driven and the vehicle drive torque of the engine becomes insufficient, resulting in a decrease in vehicle speed and There was a problem that it caused the engine cooling water temperature to rise excessively. Further, in the case of an automatic vehicle, the engine speed is set to a high value in consideration of the loss in the torque converter and the like, which is also a cause of the above-mentioned problem.

The present invention has been made to solve such a problem, and is intended for a cooling device using an electromagnetic clutch by an engine even when the vehicle runs while setting a shift range to a low speed range on an uphill road or the like. An object of the present invention is to provide a compressor control method for a vehicle air conditioner that can appropriately control the drive of the compressor to improve the durability of the electromagnetic clutch and prevent overheating of the engine.

(Means for Solving the Problems) In order to achieve the above object, the present invention drives a compressor via an electromagnetic clutch by a vehicle traveling engine and drives the compressor when the engine speed is equal to or higher than a predetermined value. In the compressor control method for a vehicle cooling device that is stopped, the predetermined value is changed according to the shift range of the transmission.

Further, it is desirable that the smaller the shift range of the transmission, the smaller the predetermined value.

Further, instead of the engine speed, it may be applied to a method of stopping the driving of the compressor when the vehicle speed is a predetermined value or more.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of a compressor drive control unit of a vehicle cooling device to which a control method of the present invention is applied. Reference numeral 1 denotes, for example, a 4-cylinder internal combustion engine, the engine 1 being a pulley 2 and a belt. 3 and the electromagnetic clutch 4, the compressor 5 of the cooling device is connected, and the compressor 5 is driven by the engine 1 when the electromagnetic clutch 4 is connected.

The engine 1 is provided with an engine cooling water temperature sensor (hereinafter referred to as “Tw sensor”) 7. The Tw sensor is composed of a thermistor or the like, and is inserted into the engine cylinder peripheral wall filled with cooling water to detect its detected water temperature signal. It is supplied to an electronic control unit (hereinafter referred to as "ECU") 6.

Engine speed sensor (hereinafter referred to as "Ne sensor") 8
Is mounted around a cam shaft or a crank shaft (not shown) of the engine 1, and a TDC signal, that is, at a predetermined crank angle position every 180 ° rotation of the crank shaft of the engine 1.
This pulse (hereinafter referred to as “TDC signal pulse”)
Is supplied to ECU6.

Further, the ECU 6 is connected with a shift range sensor 9 for detecting a set shift range of the transmission and a switch (hereinafter referred to as “AC switch”) 10 for turning on / off the operation of the cooling device, and these detection signals Is supplied to ECU6.
In this embodiment, the transmission is an automatic transmission, and a 3-range of D _4, D _3, 2-speed as shift range for forward. These ranges D _4, D _3, 2-speed variable range of the speed change gear position in each range (hereinafter referred to as "shift range"), respectively first speed (lower speed) 4th speed (high speed side), 1-speed to 3 The speed range and the second speed are fixed. ECU6
Controls the connection and disengagement of the electromagnetic clutch 4 based on the input signals from the sensors 7 to 9 and the AC switch 10.

FIG. 2 shows a flowchart of a program for controlling the electromagnetic clutch 4 in the ECU 6. This program is
It is executed every time a TDC signal pulse is generated.

First, the engine speed Ne is the first predetermined speed N
_It is determined whether or not it is higher than _HAC1 (for example, 6,000 rpm) (step 201), and when the answer is affirmative (Yes), the first timer t _HACON comprising a down counter is _set to the predetermined time t _HACON.
After setting (for example, 0.5 seconds) and starting this (step 216), the electromagnetic clutch 4 is disengaged, or the disengaged state is continued and this program ends. That is, when the engine speed eNe> N _HAC1 is high, the compressor 5 is not driven by the engine 1 to improve the durability of the electromagnetic clutch 4. Here, the first timer t _HACON is set in step 213 described later.
A predetermined time t _HACOFF (for example, 0.5 seconds) is set at and the second timer t _HACOFF is started, and the connection and _{disconnection of the} electromagnetic clutch 4 is prevented from being repeated due to a temporary fluctuation of the engine speed Ne. It is used to

When the answer to step 201 is negative (No), that is, when the engine speed Ne ≦ N _HAC1 is satisfied, it is determined whether or not the AC switch 10 is turned on (step 202). When this answer is negative (No), it is judged whether or not the count value of the second timer t _HACOFF is equal to 0 (step 21).
5) If the answer is negative (No), the connection of the electromagnetic clutch 4 is continued (step 214), while if the answer to step 215 is affirmative (Yes), the steps 216 and 217 are executed to execute the electromagnetic The clutch 4 is released. That is, AC switch
From the state where 10 is turned on and the electromagnetic clutch 4 is connected by executing the step 213, the AC switch 10
When is turned off, the electromagnetic clutch 4 is _kept connected for a predetermined time t _{HACOFF and then released} .

If the answer to step 202 is affirmative (Yes), that is, the AC switch
When 10 is turned on, it is determined whether or not cranking is being performed (step 203). This determination is performed by determining whether or not the engine speed Ne is lower than 400 rpm, for example. When the answer to step 203 is affirmative (Yes), that is, during cranking, the third timer t _HACCR is set to a predetermined time t _HACCR (for example, 5 seconds) and started (step 204), and the steps 216 and 217 are executed. Go forward and do not connect the electromagnetic clutch 4.

When the answer to step 203 is negative (No), that is, when cranking is not in progress, it is determined whether or not the count value of the third timer t _HACCR started at step 204 is equal to 0 (step 205). When the answer is negative (No), that is, when the predetermined time t _HACCR has not elapsed after the end of the cranking, the above-mentioned step is performed as during the cranking.
Continue to 216,217. When the answer to step 205 is affirmative (Yes), it is determined whether the vehicle is an automatic vehicle (step 206). If the answer is no (No), or if the vehicle is a manual mission vehicle, immediately proceed to step 212.
On the other hand, when the vehicle is an automatic vehicle, it is determined whether the engine cooling water temperature Tw is higher than a predetermined temperature T _WHAC (for example, 105 ° C.) (step 207).

When the answer to step 207 is negative (No), that is, Tw ≦ T _WHAC is satisfied, the engine does not overheat and the process proceeds to step 212, and the answer to step 207 is affirmative (Yes), that is, Tw> T _WHAC is satisfied. In step 211, which will be described later, the determination rotation speed N _HACCT used to determine whether or not to connect the electromagnetic clutch 4 is _set to the second predetermined rotation speed N _HACCT0 (for example, 5,000 rpm) (step 20).
8), the shift range of the transmission is determined whether or not the D ₄ range (step 209). When the answer is negative (No), the process immediately proceeds to step 211, while when the answer is affirmative (Yes), the determination rotation speed N _HACCT is _set to the second predetermined rotation speed N.
_Third predetermined speed N _HACCT1 higher than _HACCT0 (eg 5,500
rpm) (step 210), and it is determined whether the engine speed Ne is higher than the determination speed N _HACCT (step 211). The answer to step 211 is affirmative (Yes), that is, Ne> N.
_{When HACCT} is established, the electromagnetic clutch 4 is disengaged, or the disengaged state is continued by the above step 215.
And the answer to step 211 is negative (No), that is, Ne ≦ N.
_{When HACCT} is established, the process proceeds to step 212 to connect the electromagnetic clutch 4 or to keep the connected state.

Thus, the engine cooling water temperature Tw is equal to the predetermined temperature T
_{In a} state higher than _WHAC , when the engine speed Ne exceeds the discrimination speed N _HACCT set in steps 208 to ₂₁₀ , the electromagnetic clutch 4 is not connected to prevent engine overheat. There is. Moreover, the determination rotational speed N _HACCT, set when the shift range of the transmission is other than the D ₄ range is lower than in the D ₄ range (N _HACCT0 <N _HACCT1), the electromagnetic clutch 4 at a lower rotation side I try to prohibit the connection. Thus, for example, a shift range at the time of uphill traveling when set to D ₃ range, even if such a high state of the engine rotational speed Ne continues long, the connection of the electromagnetic clutch 4, the separable properly It is possible to control and prevent overheating of the engine.

In step 212, it is judged whether or not the count value of the first timer t _HACON started in step 216 is equal to 0, and while the answer is negative (No), the disengaged state of the electromagnetic clutch 4 is continued. (Step 217) and the answer is affirmative (Ye
s), the second timer t _HACOFF is set to the predetermined time t
Set _HACOFF and start it (step 21
3) The step 214 is executed to end the program.

Although the engine speed is used as a parameter for determining connection / disconnection of the electromagnetic clutch 4 in the above-described embodiment, the vehicle speed may be used instead of the engine speed. That is, the electromagnetic clutch 4 is disengaged when the vehicle speed is equal to or higher than a predetermined speed, and this predetermined speed is set to D ₄
When a range other than the range is selected, the value may be smaller than that when the D ₄ range is selected.

(Effects of the Invention) As described in detail above, according to the present invention, as described in claim 1, when the compressor is driven by the vehicle traveling engine through the electromagnetic clutch and the engine speed is equal to or higher than a predetermined value, In the compressor control method for the vehicle air-conditioning system for stopping the drive of the compressor, since the predetermined value is changed according to the shift range of the transmission, the drive of the compressor via the electromagnetic clutch by the engine is changed. It can be controlled appropriately according to the gear shift range of the machine, and prevents overheating of the engine and improves the durability of the electromagnetic clutch even when the vehicle is traveling on a downhill range such as a low gear range. The effect that it can be achieved is produced.

Further, as described in claim 3, substantially the same effect can be obtained by using the vehicle speed instead of the engine speed.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a compressor drive control unit of a vehicle cooling device to which a control method of the present invention is applied, and FIG. 2 is a flow chart of a program for controlling connection / disconnection of an electromagnetic clutch. 1 ... Engine, 4 ... Electromagnetic clutch, 5 ... Compressor,
6 ... Electronic control unit (ECU), 8 ... Engine speed sensor, 9 ... Shift range sensor.

Claims (4)

(57) [Claims] 1. A compressor control method for a vehicle air-conditioning system, wherein a compressor for driving a vehicle is driven through an electromagnetic clutch, and the compressor is stopped when the engine speed is equal to or higher than a predetermined value. A method for controlling a compressor of a vehicle air-conditioning device, characterized in that the predetermined value is changed according to a shift range of the machine. 2. The compressor control method for a vehicle air conditioner according to claim 1, wherein the transmission is an automatic transmission, and the predetermined value is reduced as the shift range is smaller. 3. A compressor control method for a vehicle cooling system, wherein a compressor for driving a vehicle is driven through an electromagnetic clutch and the compressor is stopped when the vehicle speed is a predetermined value or more. The method of controlling a compressor of a vehicle air-conditioning system, characterized in that the predetermined value is changed according to the gear shift range. 4. The compressor control method for a vehicle air-conditioning system according to claim 3, wherein the transmission is an automatic transmission, and the smaller the shift range is, the smaller the predetermined value is.