JPH0732172Y2 - Blower motor controller for automobile air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a blower motor controller for an automobile air conditioner, and more particularly to a controller having a failure determination function.

(Prior Art) Generally, a motor failure determination device is disclosed in
As shown in Japanese Patent Laid-Open No. 58-108990, a detector for detecting the number of rotations of the motor is provided, and when the output signal from this detector exceeds a predetermined value, the application of the power supply voltage to the motor is cut off and the motor is forcibly forced. Those that are stopped, or JP-A-58-154
As disclosed in Japanese Patent No. 387, it is known that lock detecting means for detecting a locked state of a motor is provided and the energization of the motor is cut off when the lock of the motor is detected.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional example, the assumed failure state is uniform like a blower motor in a state in which it is excessively rotated or does not rotate at all, and particularly in an air conditioner for an automobile. In a device such as a blower motor in which the rotation speed originally changes centering on the set rotation speed due to changes in the ventilation resistance of the air conditioning duct or the so-called ram pressure, it is possible to make an erroneous failure determination. There is a problem in that it is not possible to make a fine failure determination such as an initial failure determination by detecting a relatively small deviation of the rotation speed.

Therefore, an object of the present invention is to provide a blower motor control device for an automobile air conditioner, which solves the problems of the above-mentioned conventional example and can perform a reliable failure determination according to the usage state of the motor.

(Means for Solving the Problem) Therefore, the blower motor control device for an automobile air conditioner according to the invention of claim 1 has a rotation speed setting means 100 for setting the rotation speed of the blower motor 20 as shown in FIG. And the blower motor 20 according to the output signal of the rotation speed setting means 100.
A blower motor controller for an air conditioner for an automobile, comprising:
Rotation speed detection means 120 for detecting the rotation speed of the rotation speed, the rotation speed set by the rotation speed setting means 100 and the rotation speed detection means 120
The blower motor 20 depends on whether the difference from the actual rotation speed of the blower motor 20 detected by
The failure determination means 130 for determining the presence or absence of the failure and the display means 140 for displaying the determination result of the failure determination means 130 are provided.

Further, in the above-mentioned configuration, as shown in FIG. 2, a fluctuation factor detecting means 150 for detecting a fluctuation factor that causes fluctuations in the rotation speed of the blower motor 20, and the failure according to the detection result of the fluctuation factor detecting means 150. A judgment level changing means 160 for changing the predetermined deviation range of the judging means 130 may be provided.

(Operation) Therefore, the failure determination unit determines the failure state by whether or not the deviation between the set rotation speed and the actual rotation speed falls within a predetermined deviation amount. Even a fluctuating blower motor can be adequately supported. Further, since the fluctuation amount of the rotation speed of the blower motor differs depending on the use condition of the air conditioner, a fluctuation factor detecting means that causes the fluctuation of the rotation speed is provided, and the judgment level changing means is used according to the output signal of the fluctuation factor detecting means. By changing the predetermined deviation range of the failure determination means, the failure can be determined at an appropriate determination level according to the usage status of the blower motor, and therefore the above-mentioned problem can be achieved.

(Embodiment) An embodiment of a blower motor control device for an automobile air conditioner according to the present invention will be described below with reference to the drawings.

This device is provided with a microcomputer 17 as shown in FIG.
Blower motor based on input signals from various sensors
It is configured to control the drive of 20.

First, 1 to 4 are mode detection switches for detecting a vent mode, a bi-level mode, a foot mode and a defrost mode, respectively, which are provided in the vicinity of a mode door arranged in an air conditioning duct (not shown) and open / close the corresponding mode doors. According to the above, it is configured to be opened / closed. In the present embodiment, the one that is closed when the corresponding mode is detected is used. In FIG. 3, the vent mode is detected.

Reference numeral 5 denotes an inside / outside air setting detection switch (not shown) for detecting the set position of the inside / outside air switching door, which is closed as shown in FIG. 3 when the inside / outside air switching door is at the inside air introducing position, for example.

Further, reference numeral 6 denotes a vehicle window detection switch (not shown) for detecting opening / closing of the vehicle window, which has a structure in which the vehicle window is closed when all the vehicle windows are closed.

The detection switches 1 to 6 described above are connected to the input terminals of the microcomputer 17 via resistors 7 to 12.

13 is a vehicle speed detector that detects the vehicle speed, 14 is a rotation speed setting device that sets the rotation speed of the blower motor 20, and A / D converters 15 and 16 respectively
Is input to the microcomputer 17 as a digital signal via.

The microcomputer 17 is a known one having a central processing unit CPU, a read only memory ROM, a random access memory RAM, an input / output port I / O and the like. A D / A converter 18 and a drive circuit 19 are sequentially connected between the microcomputer 17 and the blower 20, and the rotation of the blower motor 20 according to a control signal output from the microcomputer 17 is performed according to a program described later. Are controlled. The rotation speed of the blower motor 20 is detected by the rotation sensor 21 and fed back to the microcomputer 17 via the A / D converter 22.

Reference numerals 23 and 24 respectively indicate a failure indicator light and a caution indicator light, which are connected to the collector side of the transistors 25 and 26 which are turned on / off by a control signal from the microcomputer 17, and are turned on when the transistors 25 and 26 are turned on. , To inform the passenger that the blower motor 20 is out of order or is in a caution state.

In addition, 27 is a DC power supply, and once the power supply is stabilized to the microcomputer 17 etc. (the part where "REG" is abbreviated in FIG. 3) 2
Voltage is supplied via 8.

FIG. 4 is a flowchart showing an example of drive control of the blower motor 20 by the microcomputer 17 described above, and the control contents will be described below with reference to the same figure.

First, the microcomputer 17 starts execution from step 200, proceeds to step 202, inputs the set rotation speed Ns of the blower motor 20 by the rotation speed setting device 14, and inputs step 204.
Go to.

In step 204, the state variable used for the calculation of the center rotational speed X described later is input. Table 1 shows the types of state variables and their values in this embodiment.

Explaining the examples of 2-3, for example, when the inside / outside air switching is set to the outside air introduction, the value of the variable F ₁ is a predetermined value α _{1 and} the value of the variable F ₂ for the inside air introduction state is zero. Becomes On the contrary, F ₁ =
0, F ₂ = α ₂ . The same applies to the treatment of each variable with respect to the blowing mode and the vehicle speed.

For inputting each state variable, a variable whose value has been converted into a table according to various control states is stored in, for example, a ROM, and is output according to the output signals of the detection switches 1 to 6 and the vehicle speed detector 13 described above. This can be done by reading from ROM.

Next, the routine proceeds to step 205, where the current rotational speed Nn of the blower motor 20 is input, and the routine proceeds to step 216.

In step 216, the central rotation speed X of the blower motor 20 is calculated based on the equation (1).

X = Ns + F ₁ ＋ F ₂ ＋ F ₃ ＋ F ₄ ＋ F ₅ ＋ F ₆ ＋ F ₇ …… (1) The blower motor 20 uses a sirocco fan, so its rotation speed fluctuates due to changes in ventilation resistance in the air conditioning duct. However, the above-described center rotation speed X has an average meaning of the changing blower motor rotation speed.

After the calculation of step 216 ends, the process proceeds to step 218, and the upper limit value Nup and the lower limit value N _LO of the failure determination value are calculated. That is, the value obtained by multiplying the above-described central rotation speed X by the calculation coefficient K ₁ is Nup, X
Is multiplied by the calculation coefficient K ₂ to obtain N _LO , and the next step 220
Go to.

In step 220, it is determined whether or not the previously input current rotation speed Nn (see step 205) is between Nup and N _LO. If it is within this range (YES), the rotation state of the blower motor 20 is Assuming normal, the process returns to the main routine (not shown) via step 228.

On the other hand, if it is determined that Nup>Nn> N _LO is not satisfied (NO), the process proceeds to step 222, and it is further determined whether Nn satisfies N ₁ >Nn> N ₂ . Here, N ₁ and N ₂ are predetermined values smaller than Nup and N _LO , and are values determined from the viewpoint of the number of rotations that requires inspection, etc., although it does not cause a motor failure state. Specifically, N ₁ = K ₃ · Nup, N ₂ = K ₄ · N _LO (K ₃ , K ₄
Is a coefficient).

Here, when it is determined that N ₁ >Nn> N ₂ is satisfied (YE
S) proceeds to step 224 and continues to drive the blower motor 20 as it is, and lights the caution indicator lamp 24 to inform the user that the motor rotation speed is in an unfavorable state.

Also, when it is determined that Nn is not in the region of N _{1 to} N ₂ (NO)
Goes to step 226 and turns off the power to the blower motor 20 (OF
F) and at the same time, the failure indicator light 23 is turned on to inform the user that the blower motor 20 is in a failure state.

Then, after the processing of the above step 224 or 226, the step
After returning to a main routine (not shown) via 228 and performing a predetermined process in the main routine, step 20 is performed again.
It will return to this routine through 0.

In summary, the operation of the present device having the above-mentioned configuration is described below. The DC power supply 27 is applied to the blower motor 20, and the blower motor 20 is driven by the drive circuit 19 that operates according to the control signal from the microcomputer 17. It is driven so that the rotation speed is preset to 14.

Here, if the control state of the air conditioner is, for example, inside air introduction and vent mode, and the vehicle speed is 50 km / h, the central rotation speed X that is the central value of the motor failure determination is X = Ns + α.
It is calculated as ₂ + α ₃ + α ₈ (see step 216 and Table 1). Then, based on the value of X, as described above, Nup, N
_{LO and} N ₁ and N ₂ are calculated from Nup and N _LO , respectively, and it is determined whether or not there is a failure state. Depending on the determination result, the motor is stopped, the failure indicator lamp is turned on, etc. (step 21
See 8 to 226). Further, when the control state such as the blowout mode changes, the value of X also changes accordingly, and Nup, N _LO , N ₁ , N
_{For 2 as} well, the newly calculated value is used to make a failure determination.

Therefore, if various control states are represented as A ₁ , A ₂ , A ₃ ..., X, Nup, N _LO in each state change according to each control state as shown in FIG. An appropriate failure determination according to the above will be performed.

Next, a second embodiment will be described with reference to FIG. The same steps as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Hereinafter, different portions will be mainly described.

In the second embodiment, when the motor rotation speed is changing toward the newly set rotation speed Ns, the motor rotation speed may largely deviate from the range of Nup to N _LO , and thus it is determined that a failure occurs. Therefore, the processing for avoiding such a state is configured as an addition to the first embodiment.

First, in step 206, the detected value of the rotation sensor 21 is input as the first current rotational speed N _n1 , and the process proceeds to step 208 to activate the timer for a predetermined time, and after a predetermined time has elapsed, that is, after stabilizing the rotation state. Go to step 210.

In step 210, the current rotation speed is input as the second current rotation speed N _n2 , and the process proceeds to step 212, where the first current rotation speed N _n1 and the second current rotation speed N input in step 206 described above are input. _It is determined whether or not the absolute value of the difference from _n2 is larger than a predetermined value. If the result of the determination is | N _n1 −N _n2 |> x (YES), it is determined that the motor rotational speed gradually changes from the lower rotational speed toward the set rotational speed, and the step is regarded as an unstable state. Proceeding to 214, the drive circuit 19 applies the maximum voltage to the blower motor 20. The application of this maximum voltage is to accelerate the arrival at the set rotation speed.

On the other hand, when it is determined in step 212 that the absolute value of the difference between N _n1 and N _n2 is smaller than the predetermined value x (NO), it is determined that the change in the motor rotation speed has reached the stable range, and the process proceeds to step 216. The same processing as that described in the first embodiment will be performed below.

The rotation speed N _n2 input in step 210 is used as the value of Nn in step 220.

(Effects of the Invention) Since the present invention is configured as described above, an erroneous determination may occur with respect to a change in the number of revolutions due to a change in the usage state of a motor that occurs in a conventional device with a fixed reference value for failure determination. There is no problem, and reliable failure determination can be performed. In addition, by using the failure determination criterion according to the usage state of the blower motor, it is possible to make a finer failure determination than ever before.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a blower motor control device for an automobile air conditioner according to the invention of claim 1, and FIG.
FIG. 3 is a functional block diagram of a blower motor control device for an automobile air conditioner according to the invention, FIG. 3 is a circuit diagram showing an embodiment of this device, and FIG. 4 is a first drive control of a blower motor by a microcomputer used in this device. Fig. 5 is a flowchart showing an example, Fig. 5 is a flowchart showing a second drive control example of the blower motor, and Fig. 6 is a central rotation speed X and an upper limit value Nu in various usage states of the blower motor in this device.
FIG. 6 is a characteristic diagram showing changes in p and lower limit value N _LO . 17 …… Microcomputer, 20 …… Blower motor, 23
...... Fault display light, 24 ...... Caution display light, 100 ...... Rotation speed setting means, 110 ...... Driving means, 120 ...... Rotation speed detecting means, 13
0: failure determination means, 140: display means, 150: fluctuation factor detection means, 160: determination level change means.

Claims (2)

[Scope of utility model registration request] 1. A blower motor control device for an automobile air conditioner, comprising: a rotation speed setting means for setting a rotation speed of the blower motor; and a driving means for driving the blower motor according to an output signal of the rotation speed setting means. Rotation speed detection means for detecting the rotation speed of the blower motor, and whether the difference between the rotation speed set by the rotation speed setting means and the actual rotation speed of the blower motor detected by the rotation speed detection means is within a predetermined deviation range. A blower motor control device for an air conditioner for an automobile, comprising: failure determination means for determining whether or not there is a failure in the blower motor, and display means for displaying a determination result of the failure determination means. 2. A blower motor control device for an air conditioner for an automobile, comprising: a rotation speed setting means for setting a rotation speed of the blower motor; and a driving means for driving the blower motor in accordance with an output signal of the rotation speed setting means. Rotation speed detection means for detecting the rotation speed of the blower motor, and whether the difference between the rotation speed set by the rotation speed setting means and the actual rotation speed of the blower motor detected by the rotation speed detection means is within a predetermined deviation range. Failure determination means for determining whether or not there is a failure in the blower motor, variation factor detection means for detecting a variation factor that causes variation in the rotation speed of the blower motor, and the failure determination means according to the detection result of the variation factor detection means. A judgment level changing means for changing the predetermined deviation range of the above, and a display means for displaying the judgment result of the failure judging means. Blower motor controller for a motor-vehicle air-conditioning apparatus according to symptoms.