JPH0645369Y2 - Control device for vehicle air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a control device for controlling the position of an air conditioning control member such as an air mix door or a mode door (air outlet door) in a vehicle air conditioner. More specifically, it relates to a control device capable of ensuring a minimum function even when the position detecting means of the control member fails.

[Prior Art] Conventionally, as an air-conditioning control device that takes measures against this kind of failure, the one described in JP-A-61-278414 is known. This device is configured to drive an actuator for a certain period of time to forcibly move the air mix door to the hot side when the position detecting device of the air mix door fails.

[Problems to be Solved by the Invention] In the meantime, the above-mentioned conventional apparatus cannot fix the air-conditioning request at all when the position detection device fails because the air-mix door is fixed to the hot side. was there.

In view of such circumstances, the present invention provides a control device that can meet the requirements of minimum, full heat (maximum heating), and full cool (maximum cooling) even if the position detection device fails. To aim.

[Means for Solving the Problems] In order to solve the above problems, the control device of the present invention is configured as shown in FIG.

First, the device of the present invention includes a control member 1 that is movable between the A position and the B position, an actuator 2 that moves the control member 1, and a drive current to the actuator 2 in response to a control signal. Actuator drive circuit 3 to supply
And position detecting means 4 for detecting the position of the control member 1.

The control member 1 corresponds to an air mixing door, a mode door, or the like, which is an adjusting means in the air conditioner. In the case of an air mix door, the A position corresponds to, for example, a full cool position (0% opening position) and the B position corresponds to a full heat position (100% opening position) (or vice versa). The actuator drive circuit 3 supplies either a continuous drive current or a pulsed drive current to the actuator 2, and supplies a continuous drive current when a continuous drive control signal is input. When a pulse drive control signal is supplied, a pulsed drive current, for example, a drive current is supplied once every 1 to several seconds.

Further, the control device of the present invention detects the abnormality of the output of the position detecting means 4, and based on the output of the failure detecting means 5, when the output of the position detecting means 5 is normal, outputs the output. Is output as the detected value θx as it is, and when there is an abnormality, instead of the output of the position detecting means 5, a predetermined C position (C
The position information generating means 6 outputs a value corresponding to ≠ A, B) as a temporary detection value θx.

In the case where the device of the present invention is, for example, a control device for an air mix door, it is desirable to set the C position to a 50% opening position exactly in the middle of the A position and the B position. As a result, the position information generating means 6 outputs the opening degree of 50% as the detected value θx. The failure detection means 5
Is, for example, when the output deviates from the range of normal use,
It has a function to judge it as a failure.

Further, the control device of the present invention locks when the stop target value θx ′ of the control member 1 and the position detection value θx output from the position information generating means 6 do not match during a predetermined time during driving of the actuator 2. Lock detecting means 7 for generating a signal
have. In this case, the control member 1 is
It is set to a value exceeding the time required to move from the position to the B position or vice versa.

Further, the control device of the present invention calculates the stop target value of the control member 1 based on the input information, and when the failure detecting means 5 does not issue the failure detection signal, the calculated stop target value is stopped as it is. Target value θ
When the failure detection means 5 outputs a failure detection signal and the calculated stop target value is the A position or the B position, the calculated stop target value is directly used as the stop target value θ.
When the fault detection means 5 outputs a fault detection signal and the calculated stop target values are not the A position and the B position, the position information generating means instead of the calculated stop target values outputs x '. The stop target value output means 8 for outputting a value equal to the position detection value of the stop target value θx ′ and the position detection value θx output by the position information generating means 6 are the stop target values output by the stop target value output means 8. A continuous drive control signal is supplied to the actuator drive circuit 3 until it coincides with θx ', and when the lock detection means 7 issues a lock signal, the actuator drive circuit 3 receives a pulse instead of the continuous drive control signal. And a drive control means 9 for supplying a drive control signal.

[Operation] The operation will be specifically described by taking as an example the case where the control device of the present invention is applied to a control device for an air mix door.
Now, it is assumed that an abnormality has occurred in the output signal of the position detection means 4 when the air mix door is at the 40% opening position, for example. In that case, the failure detection means 5 first issues a failure detection signal. Then, no matter what the actual detection value of the position detecting means 4, the position information generating means 6 automatically detects the C position (50
The value corresponding to (% opening position) is output as the detected value θx. That is, θx = 50% is output.

On the other hand, in this state, the stop target value output means 8 calculates if the stop target value internally calculated (including in this calculation the case where it is manually set from the outside) is 0%,
The value is output as it is as the target stop value θx ′. Then, the drive control means 9 supplies a continuous drive control signal to the actuator drive circuit 3 according to the output, whereby the actuator 2 continuously moves the air mix door (control member 1) toward the 0% opening position direction. To move.

Then, when the 0% opening position is reached, the air mix door (control member 1) cannot move any more and enters the locked state. If the continuous drive current is continuously supplied to the actuator 2 as it is, the actuator 2 or the drive mechanism will be damaged. Therefore, in the device of the present invention, the lock detection means 7 detects that the lock has occurred. Although the actuator 2 is being driven, the lock is determined even after the predetermined time has passed, the position detection value θx and the stop target value θ
This is done when x'does not match. That is, when the air mix door (control member 1) is locked at the 0% opening position, the stop target value 0% and the position detection value θx = 50% do not match forever. As a result, a lock signal is issued from the lock detecting means 7 after a predetermined time has elapsed.

When a lock signal is issued from the lock detection means 7, the drive control means 9 supplies a pulse drive control signal to the actuator drive circuit 3, whereby a pulsed drive current is supplied to the actuator 2. This prevents the actuator 2 from being damaged even if the air mix door (control member 1) is locked.

Further, the stop target value calculated by the stop target value output means 8 is 10
When it reaches 0%, that value is used as it is as the target stop value θ
Output as x '. Then, the actuator 2 is controlled in the same manner as in the case of 0% described above, and the opening position of the air mix door (control member 1) is moved to the position of 100%.

The stop target value calculated by the stop target value output means 8 is 0.
If it is neither% nor 100%, the stop target value output means 8 sets the stop target value θx to a value equal to the position detection value θx (θx = 50% in this case) output by the position information generating means 6. ’ That is, θx ′ = 50%. Therefore, since the stop target value θx ′ and the position detection value θx match from the beginning, the drive control means 9 does not output the drive control signal and the air mix door (control member 1) is stopped at that position. To be

As described above, even when an abnormality occurs in the output of the position detection unit 4, the air mix door (control member 1) can be stopped at the full cool position and the full heat position at least.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

In this embodiment, the central portion of the control device is composed of the microcomputer 30. First, to describe the mechanical configuration of the air conditioner, this air conditioner is an air-mix type that mixes cool air and warm air at an appropriate ratio and sends the air, from the upstream side to the downstream side of the blower duct 20, An intake damper 21, a blower 22, an evaporator 23, a heater 24, and an air mix door 25 are provided. The opening of the air mix door (control member) 25 is adjusted by the actuator 2, and the air that has passed through the evaporator 23 is divided into the heater 24 side and the bypass side. Finally, the mixing ratio of the cool air and the warm air is adjusted, and the air is blown out. It regulates the temperature.

The microcomputer 30 includes a CPU, a ROM, a RAM, an input / output port, and a timer. The failure detection means 5, the position information generation means 6, the lock detection means 7, and the stop target value output means 8 shown in FIG. , Drive control means 9. Then, an output from a potentiometer (position detecting means) 31 for detecting the position of the air mix door 25 is input to the microcomputer 30 via an A / D converter 32. Signals are also input to the microcomputer 30 from other sensors and temperature setting devices.

Then, the microcomputer performs an operation based on those signals, supplies the result as a control signal to the drive circuit 3, and controls the air mix door 25. Below, the third
The control processing procedure of the air mix door by the microcomputer will be described with reference to the flowchart of the drawing.

When this control program starts, it is first judged whether or not the detection signal (θx) of the potentiometer 31 is abnormal (step 101). The criterion for judgment is whether or not the detected value deviates from the output range during normal use.

If it does not deviate (NO), it is normal,
The failure flag 1 is reset (step 102). When it deviates (in the case of YES), it is judged to be a failure, the failure flag 1 is set (step 103), and the position detection value θx is automatically set to 50% (step 104).

Then, in the next steps 105 and 106, whether or not the request is MAX COOL (maximum cooling) and MAX HEAT (maximum heating)
Or not. If it is MAX COOL (YES), set the stop target value θx ′ to 0% (step
108), if it is MAX HEAT (YES), the stop target value θx ′ is set to 100% (step 109).

Then, in steps 108 and 109, the actuator drive circuit 3 is supplied with a continuous drive control signal for moving the air mix door 25 to the opening positions of 0% and 100%, respectively. When the potentiometer 31 functions normally, when the position detection value θx reaches 0% and 100%,
The supply of the drive control signal is stopped and the actuator 2 is stopped.

On the other hand, if the request is neither MAX COOL nor MAX HEAT (in the case of NO), the presence or absence of the failure flag 1 is confirmed in step 107, and if the failure flag 1 is not set (in the case of NO), the normal auto operation is performed. Control is performed (step 110). That is, the actuator 2 is driven until the calculated stop target position reaches the air mix door 25, and when it reaches, the drive is stopped.

If it is confirmed in step 107 that the failure flag 1 is set (YES), the stop target value θx ′ is set to a value equal to θx. In this case, since θx = 50% in step 104, θx ′ = 50%
(Step 111). By doing so, the stop target value θx and the position detection value θx ′ match, so that the output of the control signal to the drive circuit 3 is stopped, and the air mix door 25
Can be stopped in its original position.

Next, the stop target value θ
When x ′ does not match the position detection value θx, it is determined that the lock is made (step 112), the pulse drive control signal is supplied to the drive circuit 3, and the pulsed drive current is supplied to the actuator 2.

This protects the actuator 2 even when the air mix door 25 is in the locked state. Also,
Due to this lock protection function, even if the potentiometer 31 fails, the air mix door 25
Can be stopped in the full cool position or the full heat position. Further, the above-mentioned protection function works even when the air mix door 25 is locked at the intermediate position.

In the above embodiment, the present invention is applied to the position control device of the air mix door, but the present invention may be applied to the position control device of the mode door or other air conditioning control members. Applicable.

[Advantages of the Invention] As described above, according to the control device of the present invention, even if the function of detecting the position of the control member is impaired, at least the A position, which is the movement limit of both ends, and It can be stopped in the B position. Therefore, when the present invention is applied to the control device of the air mix door, even if the position detecting means is broken, the air mix door can be stopped at least at the full cool position and the full heat position, and the cooling and heating can be performed. Can be flexibly deal with.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention, FIG. 2 is a configuration diagram of an embodiment of the present invention, and FIG. 3 is a flow chart shown for explaining a control processing procedure in the same embodiment. 1 ... Control member, 2 ... Actuator, 3 ... Actuator drive circuit, 4 ... Position detecting means, 5 ... Failure detecting means, 6 ... Position information generating means, 7 ... Lock detecting means, 8 ... Stop target value output means, 9 ... Drive control means,
25: Air mix door (control member), 31: Potentiometer (position detection means).

Claims (1)

[Scope of utility model registration request] 1. A control device for an air conditioner for a vehicle, comprising the following elements (a) to (v). (A) A control member that is movable between the A position and the B position. (A) An actuator that moves the control member. (C) An actuator drive circuit that supplies either a continuous drive current or a pulsed drive current to the actuator in response to a control signal. (D) Position detecting means for detecting the position of the control member. (E) Failure detection means for detecting an abnormality in the output of the position detection means. (F) Based on the output of the failure detection means, when the output of the position detection means is normal, the output is directly output as the detection value, and when there is an abnormality, it is set separately instead of the output of the position detection means. Position information generating means for outputting a value corresponding to a predetermined C position (C ≠ A, B) between the A position and the B position as a temporary detection value. (G) Lock detecting means for generating a lock signal when the stop target value of the control member and the position detection value output by the position information generating means do not match during the driving of the actuator even after a predetermined time. (H) The stop target value of the control member is calculated based on the input information, and when the failure detection means does not issue a failure detection signal,
When the calculated stop target value is output as it is, the failure detection means issues a failure detection signal, and the calculated stop target value is the A position or the B position,
When the calculated stop target value is output as it is, the failure detection means issues a failure detection signal, and the calculated stop target values are not the A position and the B position, the calculated stop target value is replaced by the above Stop target value output means for outputting a value equal to the position detection value from the position information generation means as a stop target value; and (c) stop output by the stop target value output means for the position detection value output by the position information generation means. A continuous drive control signal is supplied to the actuator drive circuit until it matches the target value, and when the lock detection means issues a lock signal, the actuator drive circuit is replaced with the continuous drive control signal by pulse drive control. Drive control means for supplying a signal.