JPS6355448B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air conditioning system for a vehicle, and more particularly to setting the stop position of an air control door such as an inside/outside air switching door when the system is stopped.

Vehicle air conditioners generally have an inside/outside air switching door that controls the amount of inside and outside air introduced, an air mixer door that adjusts the mixing ratio of cold air from the evaporator and warm air from the heater core, and a mode switch that sets the blowing direction of conditioned air. It is equipped with various air control doors such as doors, and by controlling these control doors based on setting signals from a temperature setting device, or control signals from an inside air sensor, outside air sensor, etc., the temperature inside the vehicle can be adjusted to the set temperature. can be automatically retained.

On the other hand, the opening degree of the various air-controlled doors mentioned above is controlled by an actuator such as a motor, but as the outside temperature gradually drops to extremely low temperatures, the oil deposited on the door bearings may Due to a decrease in viscosity or due to freezing of moisture adhering to the bearing part, the air control door has the characteristic L shown in Figure 1.
As shown in , the torque required for the rotation gradually increases. On the other hand, the torque of the actuator mentioned above gradually decreases as shown in characteristic M due to thermal contraction of various parts and solidification of the glue.For this reason, when the outside temperature drops to near freezing temperature, the actuator torque becomes smaller than the door torque. As a result, a situation arises in which the door is not driven at all. Therefore, if an air conditioner is used in the summer or autumn when the outside temperature is relatively high, and a vehicle is left with the air control door set to cooler mode and the vehicle is used at an extremely cold temperature, the air control door will not be activated at this temperature. The door does not move from the cooler mode to the heater mode at all and remains locked in the cooler mode.
Therefore, when the air conditioner is operated, a large amount of low-temperature outside air is blown out toward the face. Therefore, not only does the feeling deteriorate for the passengers, but also
This has become an important problem in terms of health and driving safety. In addition, in winter, when the vehicle air conditioner operates in heater mode and the cabin temperature rises to the appropriate heating temperature, in a stable state, the air mixer door introduces only a portion of the cold air from the evaporator side. , located in such a way as to allow for air ventilation. However, if the air conditioning door stops in a position that introduces some of the cold air from the evaporator side, and then starts the vehicle air conditioning system the next morning when the outside temperature is low, cold air will start blowing out immediately after the air conditioning system starts. I ended up being
This had the disadvantage of significantly reducing the feeling of occupants.

The object of the present invention is to set air control doors such as air mix doors and mode switching doors to full heater mode when the air conditioner is not operating, so that even if the air control door is locked at extremely cold temperatures, cold air will not be blown out. In this way, the above-mentioned drawbacks are eliminated, and will be explained in detail below using examples.

FIG. 2 is a circuit diagram showing an embodiment of the vehicle air conditioner according to the present invention.
A wiring 3 is connected to the ignition switch 2 via an ignition switch 2, and a contact 4 is controlled by a relay 4.
The wiring 5 is connected through c, the voltage from the wiring 3 is supplied to devices other than the vehicle air conditioner, and the voltage E from the wire 5 is used as a system power source for the vehicle air conditioner. A transistor 6 is connected to the relay 4, the output from an operational amplifier 7 as a comparator is supplied to the base side of the transistor 6, and the connection point between the resistors 8 and 9 is connected to the inverting input side of the operational amplifier 7. A reference voltage E ₂ obtained from the reference voltage E 2 is supplied to the non-inverting input side, and a voltage E ₁ obtained from the connection point between the resistor 10 and the capacitor 11 is supplied to the non-inverting input side. Note that the resistor 8 is connected to the wiring 5 and also to the wiring 3 via the diode 12, and the resistor 10 is connected to the wiring 3.
A series circuit consisting of a diode 13 and a resistor 14 is connected to this resistor 10. Here, if the ignition switch 2 is on, the voltage E ₁ obtained from the connection point between the resistor 10 and the capacitor 11 will be larger than the voltage E ₂ obtained from the connection point between the resistor 8 and the resistor 9. Therefore, the output of operational amplifier 7 becomes H level, transistor 6 is turned on, relay 4 is energized, its contact 4c is turned on, and voltage E is obtained from wiring 5. Furthermore, when the ignition switch 2 is switched from on to off, the condition that E ₁ > E ₂ is established for a predetermined period of time due to the discharge of the capacitor 11 is obtained, so the output of the operational amplifier 7 remains at H level during this period, which causes the relay 4 to is energized for a predetermined time even after the ignition switch 2 is turned off, during which time the contact 4c is turned on and the voltage E is obtained from the wiring 5 for a predetermined time. After a predetermined period of time has elapsed, the relay 6 is deenergized and the voltage of the wiring 5 becomes zero.

15 is a multiplexer, and its input side receives the signal S ₁ from the inside air sensor and the signal from the outside air sensor.
S ₂ and a signal S ₃ from a mode setter are supplied, and a signal S ₄ from a temperature setter 16 is supplied via a two-channel analog multiplexer 17 constituting selection means A. The temperature setting device 16 is made up of, for example, a variable resistor, and by operating it in a direction that sets the temperature inside the vehicle compartment high, that is, in a heater mode direction, the signal S ₄ sets the temperature from a low voltage close to 0V. The power supply voltage V supplied to the device 16
changes in the direction of high voltage. The above voltage V is the wiring 5.
This voltage is obtained by lowering the voltage E through a voltage dividing resistor, and this voltage V sets the air conditioner to full heater mode (maximum heating state). Further, the multiplexer 17 is supplied with the signal S ₄ from the temperature setting device 16 and the full heater mode setting voltage V whose magnitude does not change from the heater mode setting circuit _B. When the control signal S5 is at the L level, it operates to supply the signal _S4 to the multiplexer 15, and when the control signal _S5 is at the L level, the heater mode setting voltage V from the heater mode setting circuit B is supplied to the multiplexer 1.
5. Note that the heater mode setting circuit B consists of voltage dividing resistors 70 and 71. The multiplexer 15 selectively sends the signals S ₁ to S ₃ and the signal from the multiplexer 17 to the A/D converter 19 based on the control signal S ₆ from the central processing unit 18 consisting of a microcomputer or the like.
From this A/D converter 19 to the central processing unit 18
A digital signal is sent to the central processing unit 18, and the central processing unit 18 generates an air mix door control signal based on this signal.
S ₇ , a mode switching door control signal S ₈ , a blower control signal S ₉ , etc., to control the opening of the air mixer door and the mode switching door, or to control the operation of the compressor, and further to the blower drive motor 20 .
The number of rotations of the blower drive motor 20 is controlled by controlling the transistor 22 on the base side of the control transistor 21 connected to the control transistor 21 . Furthermore, this central processing unit 18 sends out control signals N ₁ to _{N 4} for controlling the opening degree of the inside/outside air switching door 23 , and the control signal N ₁ is sent to one input terminal of the exclusive or circuit 24 . The control signals N ₂ and N ₃ are supplied to one input terminal of the inverting circuits 25 and 26, and the control signal N ₄ is supplied to one input terminal of the NAND circuit 27. Incidentally, the exclusive sieve-OR circuit 24 and the NAND circuit 27 constitute a switching means C. The above control signal _N1 is a signal for setting the amount of outside air introduced relative to inside air introduction, that is, the outside air introduction rate to 0%, the control signal _N2 sets the outside air introduction rate to 15%, and the control signal _N3 sets the outside air introduction rate to 30%. , control signal _N4 is a signal for setting the outside air introduction rate to 100%, and is a signal for setting the outside air introduction rate to 100%, and is a signal for setting the outside air introduction rate to 100%.
26. The output from the NAND circuit 27 is a position selection switching transistor 32, 33, whose emitter side is supplied with voltage E and whose collector side is connected to position selection contacts 28, 29, 30, and 31, respectively.
34 and 35, and the transistors 32 to 35 constitute an opening control means D,
For example, it consists of a PNP type transistor. The position selection contacts 28 to 31 constitute a stop position controller 36 for the inside/outside air switching door 23, and this stop position controller 36 is connected to an output gear 38 that is linked to a motor 37.
It has a rotational position setting conductive plate 39 integrated with the
This conductive plate 39 has a disc shape and has a notch 40 in a part of its outer periphery, and the position selection contacts 28 to 31 are positioned on the locus of this notch 40.
For the motor 37, the voltage E is applied to each contact 28-3.
1. It is supplied via the conductive plate 39 and the common contact 41, and when the motor 37 rotates, the output gear 38 rotates and the rotation angle α of the switching door 23 is controlled. For example, exclusive sieve-or circuit 24
When an L level output is supplied from the transistor 32 and only the transistor 32 is turned on, the input to the motor 37 is cut off when the contact 28 faces the notch 40, and the motor 37 stops at that position, so that the inside/outside air switching door is closed. The rotation angle α of 23 reaches the maximum and stops, thereby making the outside air introduction rate 0%. For example, when the transistor 35 is turned on, the voltage E is supplied to the motor 37 via the transistor 35, the contact 31, the conductive plate 39, and the common contact 41, and the motor rotates, thereby causing the rotation of the inside and outside air switching door 23. The moving angle α becomes the minimum, and the contact point 31 reaches the notch 4.
0, the input to the motor 37 is cut off, the inside/outside air switching door 23 stops when the rotation angle α becomes the minimum, and the outside air introduction rate is set to 100%. Therefore, the position selection switching transistor 3
By selecting any one from 2 to 35 and turning it on, the outside air introduction rate can be set to 0%, 15%, 30%, or 100%.

An OFF detection circuit F is constituted by a resistor 42 whose one end is connected to the wiring 3 and a Zener diode 43, and a voltage signal _S5 obtained from this detection circuit F is supplied to one input terminal of an inverter OR circuit 44. The other input terminal of this OR circuit 44 is supplied with the off setting output signal _S10 from the central processing unit 18, and the output of this OR circuit has its collector side connected to the collector side of the transistor 22, and its emitter side connected to the ground. The output from the OR circuit 44 becomes H level, and when the transistor 45 is turned on, the collector potential of the transistor 22 becomes the ground potential, which turns off the transistor 21 and turns off the blower. The drive motor 20 is set to a stopped state. Further, the voltage signal S ₅ is supplied to the other input terminal of the inverter OR circuit 44 and further supplied as a control signal to the multiplexer 17 . This voltage signal _S5 is applied to the Zener diode 4 when the ignition switch 2 is on.
The voltage becomes H level, which is equal to the Zener voltage of No. 3, and when the ignition switch 2 is turned off, the voltage goes to L.
level voltage (0V).

Therefore, to explain the operation in the above configuration, first, if the ignition switch 2 is turned on, voltage is supplied from the wiring 3 to control devices other than the air conditioner, and the off detection circuit F is configured. The voltage signal _S5 obtained from the connection point between the Zener diode 43 and the resistor 42 becomes H level and is supplied to one input terminal of the inverter OR circuit 44, so the output of this OR circuit 44 is When the signal _S10 supplied to the other input terminal of 44 goes low, it goes high, so the transistor 45 is turned on and the blower drive motor 20 is set to a stopped state. However, if the signal _S10 becomes H level, the OR circuit 44
Since the output of transistor 45 becomes L level,
is turned off, the blower drive motor 20 becomes rotatable, and its rotational speed is determined by the transistor 22.
Control signal for setting the rotation speed supplied to the base side of the
Controlled under S ₉ . Also, H level voltage signal S ₅
is supplied to one input terminal of the exclusive OR circuit 24, a signal obtained by inverting the signal _N1 is obtained on the output side, and the above-mentioned H level voltage signal is obtained.
When _S5 is supplied to one input terminal of the NAND circuit 27, the output of the NAND circuit 27 is obtained as a signal obtained by inverting the signal _N4 . That is, when the ignition switch 2 is on, the exclusive OR circuit 24 and the NAND circuit 27 function as an inverting circuit. Therefore, the control signal N ₁ ,
When any one of N ₂ , N ₃ , and N ₄ becomes H level, the signal is inverted and becomes L level, turning on any of the transistors 32 to 35, and the position selection contact 28 corresponding to that transistor is turned on. -31 is selected, and the outside air introduction rate is set to a predetermined outside air introduction rate. Further, when the voltage signal S ₅ is supplied as a control signal to the multiplexer 17, the multiplexer 17 is set to directly send the signal S ₄ from the temperature setting device 16 to the multiplexer 15 side.

Therefore, for example, when the temperature setting device 16 is operated in a direction that increases the vehicle interior temperature to the maximum, that is, in the direction of full heater mode, the voltage of the output signal _S4 supplied from the temperature setting device gradually increases, and the voltage increases. V is reached, which is multiplexer 15, A/
Since the voltage is supplied to the central processing unit 18 via the D converter 19, the central processing unit 18 operates the air mix door, mode switching door, etc. in the full heater mode (the air mix door minimizes the cold air from the evaporator and sets the mode in the mode) based on this voltage V. The switching door controls control signals S 7 and S 8 to set the mode in which the conditioned air is blown out toward the feet, and also controls the control signals S ₇ and S ₈ to set the rotation speed of the blower drive motor 20 to high speed.
Adjust the size of S ₉ . Furthermore, the central processing unit 18 sets the voltage level of the control signal _N4 to H level,
This brings the outside air introduction rate to 100%. Also, when the temperature setting device 16 is operated in a direction that lowers the vehicle interior temperature, that is, in the cooler mode direction, the control signal S ₄ is activated.
Since the size of the central processing unit 18 becomes smaller,
Based on this, the magnitude of the control signals S ₇ , S ₈ , S ₉ is adjusted to control the air mix door, mode switching door,
Control the blower to cooler mode. Also, the outside air introduction rate is reduced by controlling the inside/outside air switching door. The central processing unit 18 is supplied with signals S ₁ and S ₂ from the inside/outside air sensors, signal S ₃ from the mode setting device, etc., and also controls the air mix door, mode switching door, and blower based on these signals. Control.

Therefore, when the ignition switch 2 is on, the temperature in the vehicle interior is automatically controlled based on the operating amount of the temperature setting device 16.

Next, when the ignition switch 2 is switched from the on state to the off state, the relay 4 continues to be excited for a predetermined period of time from the time when the ignition switch 2 is turned off, so that the voltage E continues to be supplied from the wiring 5 for a predetermined period of time. On the other hand, when the ignition switch 2 is turned off, the voltage signal _S5 supplied from the Zener diode 43 becomes L level, so the multiplexer 17 is switched, and the multiplexer 17 is set to the voltage V, that is, the full heater mode. Since the voltage V to be used is supplied, the central processing unit 18 uses this voltage V to set the air mix door and the mode switching door to the full heater mode. Furthermore, the control signal S ₉ is set to a magnitude that increases the rotation speed of the blower drive motor 20, and at this time, an L-level voltage signal S ₅ is applied to one input terminal of the inverter OR circuit 44. This OR circuit 44 is independent of the magnitude of the control signal _S10 that is supplied to the other input terminal of the OR circuit 44.
Since the output of becomes H level and the transistor 45 is turned on, the collector voltage of the transistor 22 becomes the ground voltage, and therefore the blower drive motor 20 remains in a stopped state even if the control signal _S9 changes to the high speed rotation level. Become. Also, since the central processing unit 18 operates to set the air conditioner to the heater mode, the control signal N ₄ becomes H level, but the L level voltage S ₅ is supplied to one input terminal of the NAND circuit 27. Therefore, the output of the NAND circuit 27 becomes H level, and the transistor 35 does not turn on.
Since the rotation angle α of the inside/outside air switching door 23 is not the minimum, the outside air introduction rate cannot be set to 100%. On the other hand, since the control signal _N1 is at L level at this time, the exclusive or circuit 24
Since only the output of the transistor 32 is turned on, the outside air introduction rate of the inside/outside air switching door 23 is 0%, that is, the inside/outside air switching door 23 is set to a mode in which outside air is not introduced. . Here, when a predetermined period of time has elapsed after the ignition switch 2 is turned off, the contact 4c is turned off, so the voltage E is immediately cut off, and the air mixer door and mode setting door are stopped while maintaining the heater mode.

Therefore, according to the present invention, when the various air control doors of the vehicle air conditioner are set to the cooler mode in summer or autumn, when the ignition switch is turned from on to off, the air mixer door , the mode setting door automatically switches from cooler mode to full heater mode and stops in this state, so even if you leave it as it is after using it in summer or autumn, and use it in extremely cold weather such as winter, the air mixer door and mode switching will not work. Since the door is already set to heater mode, the heat from the heater core can be reliably blown out from the footwell outlet even under conditions where the air mixer door and mode switching door become locked due to insufficient torque, and the heat from the heater core can be reliably blown out from the footwell outlet. It can enhance the feeling. Immediately after ignition switch 2 is turned off, the outside air intake rate of the inside/outside air switching door is set to 0% and the full heater mode is not set, so cold outside air is introduced in extremely cold weather. It is possible to solve problems related to the feeling and health of passengers and driving safety without causing problems. Further, even if the central processing unit 18 operates to set the rotation speed of the blower to the high-speed heater mode immediately after the ignition switch 2 is turned off, the power input to the blower drive motor 20 is not activated by the ignition switch. Since the system is stopped at the same time as the ignition switch 2 is turned off, there is no risk of warm air being blown out immediately after the ignition switch 2 is turned off in the summer, and unnecessary operation of the blower drive motor can be omitted, resulting in power savings. .

Further, according to the present invention, even when the air conditioner is operated in the summer, since the air mixer door and the mode switching door are set in advance to the heater mode direction, warm air that has not yet been cooled by the evaporator is generated at the beginning of the operation of the air conditioner. Since warm air is blown out from the feet, warm air is not blown onto the face, preventing a decrease in feeling. Furthermore, when used in the winter, the air mixer door is set to a mode that allows some outside air to enter, and even if the ignition switch is turned off and the vehicle air conditioning system is stopped, the air mixer door is also set to full heater mode. Therefore, there is no risk of cold air being introduced when starting the vehicle air conditioner.

Although the present invention has been described as controlling the air mixer door and mode switching door to the full heater mode when the ignition switch is turned off, the present invention is not limited to this, and may include means for fully opening the water tank of the heater core. By adding this, the problem caused by the water tank not opening in extremely cold weather can be solved.

[Brief explanation of drawings]

FIG. 1 is a characteristic diagram for explaining problems in a conventional vehicle air conditioner, and FIG. 2 is a circuit diagram showing an embodiment of the vehicle air conditioner according to the present invention. 1...Power supply, 2...Ignition switch,
3, 5... Wiring, 4... Relay, 15, 17...
Multiplexer, 16... Temperature setting device, 19...
A/D converter, 18...Central processing unit, 20...
Blower drive motor, 23...Inside/outside air switching door,
36...stop position controller.

Claims (1)

[Claims] 1. The opening degree of the air mixer door that adjusts the mixing ratio of cold air and warm air based on the setting signal from the temperature setting device, the opening degree of the mode switching door that controls the air blowing direction, and the internal/external air switching. In a vehicle air conditioner equipped with a control circuit that controls the opening degree of a door and the rotation speed of a blower for introducing inside and outside air, there is provided a heater mode setting circuit that sends out a heater mode setting signal, a setting signal from the temperature setting device, and a setting signal from the temperature setting device. selection means for selecting one of the heater mode setting signals from the heater mode setting circuit and sending it to the input side of the control circuit; and a selection means for detecting that the power switch of the control circuit is turned off; and detection means for controlling the selection means so that the selection means selects the heater mode setting signal, so that the heater mode setting signal is sent to the control circuit immediately after the power switch is turned off. An air conditioner for a vehicle, wherein the control circuit operates to set the air mixer door to warm air blowing mode and the mode switching door to footwell blowing mode. 2 The opening degree of the air mixer door that adjusts the mixing ratio of cold air and warm air based on the setting signal from the temperature setting device, the opening degree of the mode switching door that controls the blowing direction of air, the opening degree of the inside/outside air switching door, and the opening degree of the inside/outside air switching door. In a vehicle air conditioner equipped with a control circuit that controls the rotation speed of an air introduction blower, a heater mode setting circuit that sends out a heater mode setting signal, a setting signal from the temperature setting device, and a setting signal from the heater mode setting circuit. selecting means for selecting one of the heater mode setting signals and sending it to the input side of the control circuit; detecting that a power switch of the control circuit is turned off and controlling the selection means; and detecting means for controlling the selection means to select the heater mode setting signal, so that the heater mode setting signal is sent to the control circuit immediately after the power switch is turned off, so that the air mixer door is in the warm air blowing mode, and the mode switching door is set in the foot blowing mode, and the opening degree control is configured to determine the output of the control circuit and send a control signal to control the opening degree of the inside/outside air switching door. and determining the output of the detection circuit, and changing the opening degree control signal of the inside/outside air switching door sent from the opening degree control means to a control signal that causes the outside air introduction rate to be 0% or a value close to this. An air conditioner for a vehicle, comprising a switching means for switching, and immediately after the power switch is turned off, the outside air introduction rate is set to 0% or a value close to this. 3. The vehicle air conditioner according to claim 2, wherein the selection means comprises a multiplexer that selects either the signal from the temperature setting device or the heater mode setting signal based on the output of the detection circuit. Device. 4. The opening degree control means includes a first switching transistor that cuts off input to the inside/outside air switching door driving motor when the outside/outside air switching door is rotated to a position where the outside air introduction rate is set to 0%. and a second switching transistor that cuts off the input to the motor when the inside/outside air switching door is rotated to a position where the outside air introduction rate is set to 100%. harmonization device. 5. The vehicle air conditioner according to claim 4, wherein the switching means comprises a switching circuit that reverses the operation of the first transistor and the operation of the second transistor based on the output signal from the detection circuit. Device.