JP2826208B2 - Air conditioner control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an air conditioner applied to an automobile having an automatic transmission.

[0002]

2. Description of the Related Art As a prior art related to this kind of engine for an automobile, for example, one disclosed in Japanese Patent Application Laid-Open No. 58-28569 is known. In this system, a bypass air passage bypassing the throttle valve is provided in the intake system, and a flow control valve is provided in the middle of the bypass air passage, and the opening of the flow control valve is controlled to control the idling time. The engine speed is controlled. When the load on the engine increases due to the shift lever of the automatic transmission being switched from the non-traveling position to the traveling position or the start of operation of the air conditioner, the control position of the flow control valve is changed to air. Correction is made to increase the flow rate to prevent the engine speed from dropping.

[0003]

However, even when such idle speed control is performed, racing is performed by depressing the accelerator pedal strongly while the air conditioner is operating, and immediately thereafter. Shift the shift lever of the automatic transmission to the P (parking) range or N
When the vehicle shifts from a non-traveling position such as a (neutral) range to a traveling position such as an R (rear drive) range or a D (drive) range, the load acting on the engine increases sharply, and the engine speed drops. Bounces on
This can cause a significant drop in rotation, leading to engine stall.

An object of the present invention is to solve such a problem reliably by devising the operation timing of the air conditioner.

[0005]

In order to achieve the above object, the present invention takes the following measures. That is, the control method of the air conditioner according to the present invention is based on a system that drives the air conditioner using a part of the driving force of the engine with the automatic transmission. In such a system, when the automatic transmission is set to the non-traveling position, and the air conditioner cut condition that the engine speed has increased to a predetermined value or more is satisfied, the operation of the air conditioner is stopped, Even if the air conditioner cut condition is canceled, the air conditioner is kept stopped until a predetermined time elapses.

[0006]

According to the present invention, when racing while the air conditioner is operating and the shift lever of the automatic transmission is set to the non-traveling position,
When the engine speed exceeds the set value, the air conditioner cut condition is satisfied, and the operation of the air conditioner is forcibly stopped. When the accelerator pedal is released and the engine speed drops suddenly to finish racing, the engine speed may drop below the set value on the way, or the shift lever of the automatic transmission may shift from the non-running position to the running position. The air conditioner cut condition is canceled when the shift operation is performed. However, in the present invention, the operation of the air conditioner is not restarted at the time of the cancellation, and the stopped state is maintained until a predetermined set time has elapsed from that time. Therefore, it is possible to prevent the load caused by the operation of the air conditioner and the shocking load caused by the shift operation of the automatic transmission from acting on the engine when the engine speed is rapidly falling. Therefore, it is possible to effectively prevent the occurrence of such a problem that the engine speed is excessively lowered and the engine is stalled.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 schematically shows an engine system mounted on a so-called automatic vehicle. In this system, the driving force of an engine 1 is shifted by an automatic transmission 2 and transmitted to driving wheels (not shown). The automatic transmission 2 has a known configuration including a torque converter 2 a, and can change the shift range by operating the shift lever 3. The shift lever 3 has a P (parking) range and an N
(Neutral) range, and an R (rear drive) range, a D (drive) range, and the like as travel positions.

The air conditioner 4 is driven by using a part of the driving force of the engine 1. Specifically, the output of the engine 1 can be transmitted to the compressor 6 of the air conditioner 4 via the electromagnetic clutch 5, and the electromagnetic clutch 5 is connected to the air conditioner amplifier 7.
Is interrupted by a command signal a from the controller. An air conditioner operation command signal b or an air conditioner stop command signal c is transmitted from the electronic control unit 8 to the air conditioner amplifier 7, and based on these signals b and c, the electromagnetic clutch 5 is turned on and off. The command signal a is output from the air conditioner amplifier 7.

The electronic control unit 8 is mainly composed of a microcomputer unit 13 having a CPU 9, a memory 10, an input interface 11, and an output interface 12, and the input interface 11 has at least A signal d from a rotation speed sensor 14 for detecting an engine rotation speed, an air conditioner switch 15 for operating and stopping the air conditioner 4
, And a signal f (referred to as “A / T input signal” in the drawing) from a shift position sensor 16 for detecting the shift position of the shift lever 3. The shift position sensor 16 outputs an OFF signal when the shift lever 3 is set to the non-traveling position, and outputs an ON signal when the shift lever 3 is set to the traveling position. The electronic control unit 8 incorporates a program for implementing the present invention in addition to a normal program for operating and stopping the air conditioner 4 in accordance with the switching operation of the air conditioner switch 15.

A program for carrying out the present invention is as schematically shown in FIG. First, step 5
In step 1, it is determined whether the air conditioner 4 is ON (whether the air conditioner 4 is operating). If the air conditioner 4 is ON, the process proceeds to step 52. If the air conditioner 4 is not ON, the routine ends. I do. In step 52, it is determined whether or not the engine speed is higher than a set value (for example, 3500 rpm). If it is higher, the process proceeds to step 53, but if it is not higher, this routine ends. In step 53, the shift lever 3 of the automatic transmission 2
Is set to the non-traveling position (the position at which the shift position sensor 16 outputs the OFF signal), and if it is set to the non-traveling position, the process proceeds to step 54. If not set, the routine ends. In step 54, the air conditioner 4 is switched to the OFF state (the air conditioner 4 is stopped). Thereafter, the process proceeds to step 55. In step 55, it is determined whether or not the engine speed is higher than the set value. If the engine speed is higher, the process proceeds to step 56, but if not, the process proceeds to step 57. In step 56, it is determined whether or not the shift lever 3 of the automatic transmission 2 is set to the non-travel position. If the shift lever 3 is set to the non-travel position, the process returns to step 54, and the routine from step 55 is repeated. If it is not set to the non-traveling position, the process proceeds to step 57. In step 57, it is determined whether or not a predetermined time has elapsed, and if the predetermined time has elapsed,
The process proceeds to step 58. If the predetermined time has not elapsed, the air conditioner 4 is kept in the OFF state until the predetermined time has elapsed. Step 58
Then, the air conditioner operation command signal b
Is output to the air conditioner amplifier 7 to output the command signal a from the air conditioner amplifier 7 to the electromagnetic clutch 5 and switch the electromagnetic clutch 5 to the connected state. By this switching, a part of the driving force of the engine 1 is transmitted to the compressor 6, the driving of the air conditioner 4 is started, and the current routine is ended.

With such a configuration, when the air conditioner 4 is in the ON state and the shift lever 3 of the automatic transmission 2 is set to the non-traveling position, the accelerator pedal is depressed to perform racing. When the engine speed exceeds the set value, the air conditioner cut-off condition is satisfied, the air conditioner 4 is forcibly turned off, and the accelerator pedal is released to release the engine. When the engine speed drops below the set value or the engine speed is higher than the set value, the automatic transmission 2 shift lever 3 is in the traveling position (shift position sensor 16 is O
At the stage when the air conditioner is switched to the position for outputting the N signal), the above-described air conditioner cut condition is released. However, in the control according to the present invention, the air conditioner 4 is kept in the OFF state until the predetermined time has elapsed even after the air conditioner cut condition is canceled, and after the predetermined time has elapsed, The air conditioner 4 is switched to the ON state. With this control, even if the shift lever 3 of the automatic transmission 2 is shifted from the non-traveling position to the traveling position in the latter half of the racing operation, the engine speed suddenly decreases due to the shock. This prevents the engine from stalling due to a large drop in rotation. The set value to be compared with the engine speed does not necessarily have to match the conventional set value, and can be modified without departing from the spirit of the present invention.

[0013]

As described above in detail, according to the present invention, in an automatic vehicle, when the automatic transmission is set to the non-traveling position, the air conditioner cut-off condition is increased when the engine speed exceeds a predetermined value. In this case, the operation of the air conditioner is forcibly stopped, and the stopped state of the air conditioner is maintained until a predetermined set time has elapsed even after the air conditioner cut condition is released. Therefore, even in a case where the shift lever of the automatic transmission is shifted from the non-travel position to the travel position in the latter half of the racing operation and the above-described air conditioner cut condition is released, the engine speed may drop excessively. Problems such as engine stall can be effectively prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration explanatory view showing one embodiment of the present invention.

FIG. 2 is a flowchart showing a control procedure of the embodiment.

[Explanation of symbols]

 1. Engine 2. Automatic transmission 4. Air conditioner

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60H 1/32 623 F02D 29 / 00,29 / 04

Claims (1)

(57) [Claims] An air conditioner is driven by using a part of the driving force of an engine with an automatic transmission, wherein the automatic transmission is set to a non-traveling position, and the engine speed is reduced. When the air conditioner cut condition that the number has risen to a predetermined value or more is satisfied, the operation of the air conditioner is stopped, and the air conditioner is stopped until a certain time elapses even if the air conditioner cut condition is released. A method for controlling an air conditioner, comprising: