JPS6313846B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air volume control device for a car air conditioner (automobile air conditioner), and in particular uses a digital computer for automatic air volume adjustment, and separately enables manual air volume adjustment. Regarding control systems.

In order to automatically control various adjustment mechanisms of a car air conditioner, a control device has been developed that uses a digital computer called a microcomputer and sequentially executes various adjustment mechanisms according to a preset control program.

When manufacturing a car air conditioner capable of such automatic control, it is desirable to have a manual adjustment function that allows the occupant to set various adjustment mechanisms to desired states.

The purpose of the present invention is to (a) have both an automatic adjustment function and a manual adjustment function in conjunction with the digital computer control of air volume adjustment, and (b) enable the selection to be easily operated using a manual adjustment lever. (c) It is an object of the present invention to provide an air volume adjustment device for a car air conditioner that can reliably guarantee manual adjustment function even when a digital computer stops functioning.

In order to achieve the above-mentioned object, the present invention provides a manual signal generating means, in addition to a first signal generating means including a digital computer, which acts on a direct current blowing motor disposed in a ventilation duct of a car air conditioner to change its blowing capacity. a second signal generating means for varying the blowing capacity of the blower motor in accordance with the adjustment lever, and further comprising first and second signals to be applied to the blower motor by the selection means responsive to the adjustment position of the manual adjustment lever; and when an abnormality in the first signal generation means is detected while the selection means is selecting the first command signal, the selection means selects the first command signal. The present invention is characterized in that a third signal is passed through which the selection of the DC motor is stopped and the blowing capacity of the DC motor is brought to a predetermined value.

In FIG. 1, numeral 10 indicates a direct current motor for blowing air, which is installed in a ventilation duct of a known car air conditioner. 11 is a digital computer, generally called a microcomputer, which includes a CPU, ROM,
It is composed of an integrated circuit including RAM, data and address buses, timing circuits, I/O ports, etc. This computer 11 is connected to known input and output elements for controlling various adjustment mechanisms of the car air conditioner.

The register 12 is one of the output elements connected to the computer 11, and receives a binary code signal calculated by the computer 11 to indicate the air blowing capacity of the car air conditioner, that is, to command the rotational speed of the DC motor 10. Memorize temporarily. The stored binary code signal is converted into an analog signal voltage by a digital-to-analog (D/A) conversion circuit 13, and then sent to an amplifier circuit 15 consisting of Darlington-connected transistors via a selection circuit 14 using an analog switch.
The driving torque of the DC motor 10 directly connected to the amplifier circuit 15 is made to correspond to the command value of the computer 11.

The selection circuit 14 includes, as another input element, a potentiometer 1 in conjunction with a manual adjustment lever 20.
6 and an OR gate 17 which is a control element.
When the output is at the "1" level, the signal voltage from the potentiometer 16 is selected, and when the output is at the "0" level, the signal voltage from the D/A conversion circuit 13 is selected and passed.

An opening/closing switch 18 interlocked with the manual adjustment lever 20 is provided as one input element of the OR gate 17, and as the switch 18 opens and closes, signals of "1" and "0" levels are applied to the OR gate 17.

As shown in FIG. 2, the manual adjustment lever 20 can be moved by sliding it on the operation panel.
OFF position, AUTO position and continuously changing
It has the positions LO-ME-HI. The OFF position is the ventilation stop position, and in this position, the ventilation switch contact 19 disposed in the power supply path is opened.
The AUTO position is an automatic adjustment position, in which the blower switch contact 19 is closed and the switch 18 is also closed. Therefore, the selection circuit 14
A signal voltage determined by the computer 11 from the A conversion circuit 13 is applied. LO-ME-
The HI position is the manual adjustment position, where the blower switch contact 19 is closed and the switch 18 is open.
Therefore, a signal voltage generated from the potentiometer 16 corresponding to the position of the adjustment lever is passed through the selection circuit 14.

The potentiometer 16 includes a contact 16A that closes when the adjustment lever 20 is in the AUTO position.
A fixed resistor 1 that generates a constant DC voltage at that time
6B, which generates a signal voltage to rotate the DC motor 10 at a low speed (corresponding to an intermediate position between LO and ME) via the selection circuit 14 when the digital computer 11 stops functioning, as will be described later.

Reference numeral 24 denotes an abnormality detection circuit of the digital computer 11, which uses a known method, for example, when a computer control program is executed, it periodically outputs a signal at "1" level.
It is connected to an output port that is set to generate a pulse signal that is at the “0” level, and the output pulse is frequency-voltage converted, and if the output voltage is above a certain level, it is considered normal, and the output is at the “0” level. If the value is lower than that, it is determined that the program is not being executed normally, and a "1" level output is generated. This output signal is connected to the reset circuit 25 and applied to the computer 11 through the NOR gate 27 together with the output of the normal power-on reset circuit 26, so that the digital computer 11 restarts the execution of the program from the initial setting. There is.

Furthermore, the output signal of the abnormality detection circuit 24 is
It is also input to the OR gate 17, and at its "1" level, the selection circuit 14 operates to pass the signal voltage from the potentiometer 16.

Further, the output signal of the abnormality detection circuit 24 is input to an oscillation circuit 28, and when the signal is at the "1" level, a pulse signal of a constant period (for example, about 1 second) is generated from the oscillation circuit 28.

23A, 23B, and 23C are indicators made of, for example, light emitting diodes, which blink at predetermined points on the operation panel 23 as shown in FIG. The AUTO indicator 23A is connected to the open/close switch 1 via the inverter 29.
8 and lights up when the manual adjustment lever 20 is in the AUTO position. LO-ME-HI indicator 2
3B is provided with three pieces, and the adjustment lever 20 is
Lights up when in any of the LO-ME-HI positions. The alarm indicator 23C is connected to the oscillation circuit 28 and blinks when the digital computer 11 stops functioning.

Power is supplied to the device from the vehicle battery 22 through the engine key switch 21 and the blower switch contact 19.
constant voltage circuit 3 except for the power amplification stage.
A voltage constant at 0 is given.

As is clear from the above description, the operation of the device of the present invention can be summarized as follows.

(1) When the adjustment lever 20 is in the OFF position, the switch contact 19 is open and the device is stopped.

(2) When the adjustment lever 20 is set to the AUTO position,
Switch contact 19 is closed and the device is operating. The digital computer 11 determines the amount of air blowing according to its control program, and stores the information in the register.
A signal voltage is generated via the D/A conversion circuit 13. The switch 18 is closed, the selection circuit 14 passes the signal voltage from the D/A conversion circuit 13, and the amplifier circuit 15 causes the DC motor 10 to change the amount of air blown according to the command from the digital computer 11. In addition, the display 23A lights up.

(3) When the digital computer 11 stops functioning, the output of the abnormality detection circuit 24 forces the selection circuit 14 to pass the signal from the potentiometer 16. If the adjustment lever 20
In the AUTO position, potentiometer 16
Since the contact 16A attached to the DC motor 10 is closed, the DC motor 10 is rotated at a medium to low speed and a constant amount of air is blown. In addition, the display 23C blinks.

(4) When the adjustment lever 23 is in the LO-ME-HI position,
Switch contact 19 closes, but switch 18
is open, and the selection circuit 14 can adjust the amount of air blown by the DC motor 10 in response to the signal voltage generated by the potentiometer 16.
At this time, there is no problem even if the computer 11 stops functioning. Further, the indicator 23 lights up.

In the embodiments described above, two signal voltages are selected by the selection circuit 14.
A mechanical contact type switch linked with the switch may also be used. In this case, OR gate 17 and switch 18 are unnecessary.

Further, the present invention can also be applied to a system in which the computer 11 issues an on/off signal whose frequency or duty ratio changes as a command signal to drive the DC motor 10. That is, instead of the registers 12 and 13, a frequency-voltage (F/V) conversion circuit or an integration circuit that converts the on-off signal into a DC voltage corresponding to its frequency or duty ratio may be provided. Alternatively, the F/V conversion circuit or the integration circuit is connected to the selection circuit 14 and the amplifier circuit 1.
5, while potentiometer 16
A voltage controlled oscillation circuit that generates an on/off signal with a frequency or duty ratio corresponding to the signal voltage generated by the potentiometer 16 may be provided between the selection circuit 14 and the selection circuit 14 .

Furthermore, it is of course possible to use a rotary knob as the manual adjustment lever.

As described above, the present invention has the advantage that selection between the automatic adjustment function and the manual adjustment function can be easily realized using the manual adjustment lever.

Furthermore, according to the present invention, if an abnormality occurs in the automatic adjustment function, the air blowing capacity is automatically adjusted to a predetermined capacity to reliably prevent air blowing that would cause discomfort to occupants in the vehicle interior. can do.

[Brief explanation of the drawing]

FIG. 1 is an electrical wiring diagram showing an embodiment of the present invention;
FIG. 2 is a front view showing the main parts of the operation panel used to implement the present invention. 10... DC motor for blowing air, 11, 12, 13
...Digital computer, register, digital-analog (D/A) forming the first signal generation means
Conversion circuit, 14... Selection circuit, 15... Amplifying circuit, 16... Potentiometer serving as second signal generating means, 17... OR gate, 18... Opening/closing switch, 19... Air blowing switch contact, 20 ...Manual adjustment lever, 21...Engine key switch,
22...Car battery.

Claims (1)

[Scope of Claims] 1. A direct current motor for blowing air installed in a ventilation duct of a car air conditioner, a first signal that generates a first command signal that changes the blowing ability of the direct current motor according to a preset control program. generating means; second signal generating means for generating a second command signal for changing the air blowing capacity by the DC motor in response to an adjustment position of the manual adjustment lever; the first signal from the first and second signal generating means;
a selection means for selectively passing the command signal or a second command signal; an amplification means for amplifying the signal passed through the selection means and applying it to the DC motor; and a selection means for selectively passing the first command signal. If an abnormality in the first signal generation means is detected during selection, the selection of the first command signal by the selection means is stopped, and the blowing capacity of the DC motor is adjusted to a predetermined value. An air volume adjustment device for a car air conditioner, comprising: a selection correction means for passing a third signal that causes