JP3102509B2 - Vehicle air conditioning controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioning control system for a vehicle, and more particularly to an air conditioning control system for a vehicle applied to an air conditioning system for energy saving.

[0002]

2. Description of the Related Art The problem of energy saving is a socially important problem nowadays, and many air conditioners for vehicles (car air conditioners) that take energy saving into consideration have come to be seen.
On the other hand, maintaining the vehicle interior immediately or stably in a comfortable state is one of the important factors for safe driving.

FIGS. 5 and 6 show a conventional car air conditioner system for energy saving. 5 is a diagram showing a configuration of an air conditioner (air conditioner), and FIG. 6 is a diagram showing a configuration of an air conditioner control device for controlling the air conditioner. The air conditioner shown in FIG. 5 includes a blower fan (blower fan) 31, an evaporator 32 which is a kind of heat exchanger disposed downstream (to the right in the drawing) of the blower fan 31, and an evaporator 32. A heater core 33 disposed on the downstream side, an inside / outside air damper 34 for switching inside / outside air taken into the air conditioner, an air mix damper 35 for adjusting the blowing temperature, and a defroster damper 36 for switching the outlet. , A ventilator damper 37, and a foot damper 38. The evaporator 32 is connected to a compressor 39 which forms a part of a cooling cycle together with the evaporator 32. When the compressor 39 is driven, a refrigerant is sent into the evaporator 32, and the refrigerant is mixed with air in the air passage. The heat is exchanged between the two to cool the air. Engine cooling water is fed into the heater core 33 through a cooling water passage, and the heat in the cooling water heats the air in the air passage. In this air conditioner, the opening and closing of various dampers and the adjustment of the strength of the blower fan are manually performed by an external operation. Here, on the upstream side and the downstream side of the evaporator 32, an evaporator introduction air temperature sensor 40 for detecting the temperature of the evaporator 32 introduction wind and an evaporator temperature sensor 41 for detecting the temperature of the evaporator 32 are provided, respectively. A water temperature sensor 42 for detecting the temperature of the engine cooling water is provided.

The air conditioning control device shown in FIG. 6 includes an air conditioner switch 43 for stopping the operation of the air conditioner, an evaporator introduction wind temperature sensor 40, and an evaporator temperature sensor 41.
, A water temperature sensor 42, and a microcomputer (hereinafter, referred to as
And a magnet clutch relay drive circuit 45. Here, the output of the air conditioner switch 43 is directly, the output of the evaporator introduction wind temperature sensor 40 and the output of the evaporator temperature sensor 41 are through an interface circuit 46, and the output of the water temperature sensor 42 is through another interface circuit 47, Each is transmitted to the microcomputer 44. The magnet clutch relay drive circuit 45 includes a compressor 39
(Not shown) of the magnet clutch (not shown)
N) A circuit for driving a magnet clutch relay (not shown) for controlling off (OFF). When the magnet clutch is on, the rotation of the engine is transmitted to the compressor 39 to drive the compressor 39, and when the magnet clutch is off. The rotation of the engine is the compressor 39
, The compressor 39 stops.

[0005] In the internal memory of the microcomputer 44, a relay switching map as shown in FIG.
4 sets the compressor on / off evaporator temperature which is the temperature of the evaporator 32 for turning on / off the magnet clutch relay and turning on / off the compressor 39 in accordance with the evaporator introduction wind temperature according to this map. The on / off control of the compressor 39 has been performed by turning on / off the magnet relay based on the evaporator temperature for turning on / off the compressor.

[0006]

However, in the above-mentioned conventional car air conditioner system for energy saving, as is apparent from FIG. 6, a temperature sensor 40 for detecting the temperature of the air introduced into the evaporator and a temperature sensor for detecting the temperature of the evaporator. In addition to the temperature sensor 41, a total of two temperature sensors are required, and the input interface circuit 46 of the temperature sensor needs to use a special one or change a normal one, and is not used for energy saving measures. There was an inconvenience that the cost was higher than that of a normal car air-conditioning system.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle air-conditioning control apparatus which can solve the disadvantages of the prior art and can realize a low-cost car air-conditioning system for energy saving.

[0008]

An air conditioner control device for a vehicle according to the present invention comprises an air conditioner switch for stopping driving of the air conditioner,
An evaporator temperature sensor for detecting the temperature of the evaporator in the air conditioner, a water temperature sensor for detecting the engine cooling water temperature, and a compressor connected to the evaporator according to a predetermined compressor on / off evaporator temperature. Control means for performing on / off control via the control unit. When the air conditioner switch is turned on, the control means estimates a state of the evaporator at that time by a predetermined method, and determines whether or not the initial value of the evaporator temperature sensor can be estimated as the ambient temperature of the air conditioner. A second function of setting the compressor on / off evaporator temperature to a value that is optimal with respect to the initial value of the evaporator temperature sensor when it is determined that the ambient temperature can be estimated; And a third function of setting the compressor on / off evaporator temperature to a predetermined constant value when it is determined that the estimation cannot be performed.

Here, the estimation of the state of the evaporator when the air conditioner switch is turned on is specifically made by judging whether or not the water temperature exceeds a predetermined reference value based on the output of the water temperature sensor. The evaporator state estimating function of the control means for estimating the state of the evaporator when the air conditioner switch is turned on, and whether the time from when the air conditioner switch is turned off to when it is turned on exceeds a predetermined reference time, The control unit for estimating the state of the evaporator when the air conditioner switch is turned on is configured to be operated by an evaporator state estimation function.

[0010]

When the air conditioner switch is turned on, the control means takes in the outputs of the evaporator temperature sensor and the water temperature sensor. Next, the control means determines the state of the evaporator when the air conditioner switch is turned on, that is, by determining whether the water temperature exceeds a predetermined reference value based on a predetermined method, for example, based on the output of the water temperature sensor, that is, It is estimated whether or not the evaporator has returned to the normal temperature, and it is determined whether or not the initial value of the evaporator temperature sensor can be estimated as the ambient temperature of the air conditioner. If it is determined that the ambient temperature can be estimated, the compressor on / off evaporator temperature is set to a value that is optimal with respect to the initial value of the evaporator temperature sensor, and it is determined that the ambient temperature cannot be estimated. , The compressor on / off evaporator temperature is set to a predetermined constant value. The control means controls the compressor on / off based on the set compressor on / off evaporator temperature.

[0011]

First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. Here, the same reference numerals are used for the same or equivalent components as those of the above-described conventional example, and the description thereof is simplified or omitted.

The embodiment shown in FIG. 1 relates to an air-conditioning control device for controlling an air conditioner (air-conditioning device) configured in the same manner as in FIG. This embodiment is an air conditioner switch 43 for stopping the operation of the air conditioner, an evaporator temperature sensor 41 for detecting the temperature of the evaporator 32 (see FIG. 5) in the air conditioner, and a heat source for the heater core 33 in the air conditioner (see FIG. 5). A water temperature sensor 42 for detecting an engine cooling water temperature and a compressor 39 connected to the evaporator 32 according to a predetermined compressor on / off evaporator temperature are connected to a magnet clutch relay drive circuit 45.
And a microcomputer 1 as a control means for performing on / off control through the microcomputer.

Here, the output of the air conditioner switch 43 is directly transmitted to the microcomputer 1 via the interface circuits 46 and 47, and the outputs of the evaporator temperature sensor 41 and the water temperature sensor 42 are transmitted to the microcomputer 1 respectively.

In the internal memory of the microcomputer 1, a relay switching map as shown in FIG.
According to this map, the compressor ON which is the temperature of the evaporator 32 that controls the ON / OFF of the compressor 39 by turning on / off the magnet relay (not shown) according to the initial temperature of the evaporator 32, that is, the initial value of the evaporator temperature sensor 41.・ OFF evaporator temperature TON ・
TOFF is set as described later, and the set T
On / off of the compressor 39 is controlled by turning on / off a magnetic clutch relay (not shown) based on ON / TOFF. Referring to the map of FIG. 2, when the evaporator initial temperature is high as in summer, the compressor on / off evaporator temperature TON / TOFF is lowered. When the evaporator initial temperature is low as in winter, the compressor is turned on.・ The evaporator temperature for turning off TON / TOFF is set high.

Next, the control operation of the microcomputer 1 in this embodiment will be described with reference to the flowchart showing the control program of FIG. When the passenger of the vehicle turns on the air conditioner switch 43, the control program starts, and the microcomputer 1 performs predetermined initialization (step S101). Next, the microcomputer 1 reads the evaporator temperature and the water temperature from the evaporator temperature sensor 41 and the water temperature sensor 42 (step S102).

Next, the microcomputer 1 determines whether or not the water temperature is higher than a predetermined reference temperature (this temperature is defined as the temperature of the cooling water when the engine is completely cooled). It is determined whether it is low (step S1).
03). Thus, the state of the evaporator 32 when the air conditioner switch 43 is turned on is estimated. In other words, when the water temperature is high, when the air conditioner switch 43 is turned on, it is determined that the engine has not yet cooled down since not much time has elapsed since the engine was stopped, and the evaporator temperature sensor 41 detects that the evaporator 32 has been cooled. It is determined that a temperature that has not returned to room temperature has been detected.
On the other hand, when the water temperature is low, when the air conditioner switch 43 is turned on, the engine is judged to be completely cold since a considerable time has elapsed since the engine was stopped, and the evaporator temperature sensor 41 detects the evaporator temperature. At the same time, it is determined that the ambient temperature of the air conditioner is also detected.

When the water temperature is low, the microcomputer 1
Then, the evaporator initial temperature read in step S102 is estimated as the ambient temperature of the air conditioner, and the compressor on / off evaporator temperature TON / TOFF which is optimal with respect to the evaporator initial temperature according to the map shown in FIG.
Is set (step S104), and when the water temperature is high,
The microcomputer 1 cannot estimate the ambient temperature of the air conditioner.
TOFF is set to a fixed value TLON * TLOFF (see the dotted line in FIG. 2) (step S105). The method of setting the evaporator temperature for turning on / off the compressor is the same as in a normal air conditioner. For example, TLON = 2.5 ° C., TL
OFF = 1 ℃.

Next, in the microcomputer 1, in step S104
Alternatively, the compressor 39 is turned on / off via the magnetic clutch relay drive circuit 45 based on the TON and TOFF set in step S105 (step S1).
06). This on / off control of the compressor 39 is continued until the air conditioner switch 43 is turned off (steps S106 and S107).

According to the first embodiment described above, the ambient temperature of the air conditioner can be estimated from the cooling water temperature. As a result, the evaporator introduction air temperature sensor becomes unnecessary, and only the evaporator temperature sensor 41 is required as the temperature sensor. Since an ordinary circuit can be used as the interface circuit 46 of the temperature sensor, a low-cost car air-conditioning system for energy saving can be realized.

[0020]

Second Embodiment Next, a second embodiment of the present invention will be described.
This embodiment is composed of the same components as those of the first embodiment described above. Therefore, the description of each component is omitted, but the control program of the microcomputer 1 is different from that of the first embodiment. Therefore, this point will be described.
In the description, the reference numerals of the first embodiment are used as they are. FIG. 4 is a flowchart showing a control program of the microcomputer 1 in this embodiment.

Here, the control operation of the microcomputer 1 in this embodiment will be described with reference to FIG. When the passenger of the vehicle turns on the air conditioner switch 43, the control program starts, and the microcomputer 1 performs predetermined initialization (step S201). Next, the microcomputer 1 reads the evaporator temperature from the evaporator temperature sensor 41 (step S202).

Next, in the microcomputer 1, the time from when the air conditioner switch 43 is turned off to when the air conditioner switch 43 is turned on is a predetermined reference time. It is determined.)
Is determined (step S20).
3). Thus, the state of the evaporator 32 when the air conditioner switch 43 is turned on is estimated. That is, if the time from when the air conditioner switch 43 is turned off to when it is turned on does not exceed the reference time, as in the first embodiment, when the air conditioner switch 43 is turned on, the engine has not yet cooled down. It is determined that the evaporator temperature sensor 41 detects a temperature at which the evaporator 32 has cooled and has not yet returned to room temperature. Conversely, if the reference time is exceeded, the air conditioner switch 4
When the engine 3 is turned on, it is determined that the engine is completely cold, and it is determined that the evaporator temperature sensor 41 is detecting the evaporator temperature and the ambient temperature of the air conditioner at the same time.

If the time exceeds a predetermined reference time,
The microcomputer 1 estimates the initial temperature of the evaporator read in step S202 as the ambient temperature of the air conditioner, and optimizes the evaporator temperature T for turning on / off the compressor based on the map shown in FIG.
If ON / TOFF is set (step S204) and the reference time is not exceeded, the microcomputer 1 cannot estimate the ambient temperature of the air conditioner, so that the compressor ON / OFF evaporator temperature TON / TOFF is set to a certain value TLON / TLOFF.
(Refer to the dotted line in FIG. 2) (step S205).

Next, in the microcomputer 1, in step S204
Alternatively, on / off of the compressor 39 is controlled via the magnet clutch relay drive circuit 45 based on TON / TOFF set in step S205 (step S2).
06). This on / off control of the compressor 39 is continued until the air conditioner switch 43 is turned off (steps S206, S207).

According to this embodiment, as in the first embodiment, a low-cost car air conditioner system for energy saving can be realized.

In the first and second embodiments, the manual air conditioner is described in which the switching of the inside and outside air, the adjustment of the outlet temperature, the switching of the outlet, and the adjustment of the air volume are performed by the occupant. It can also be applied to automatic air conditioners. Further, in these embodiments, the case where the setting of the evaporator temperatures TON and TOFF for turning the compressor on and off in accordance with the evaporator initial temperature is performed based on the map of FIG. 2 is exemplified. It is also conceivable to adopt a configuration in which the formula is stored in a memory in advance, and the microcomputer 1 calculates by calculation based on the formula.

[0027]

As described above, according to the present invention,
The control means estimates the state of the evaporator when the air conditioner switch is turned on, that is, whether or not the evaporator has returned to room temperature, and whether or not the initial value of the evaporator temperature sensor can be estimated as the ambient temperature of the air conditioner. The evaporator temperature for compressor on / off is set to a value that is optimal for the initial value of the evaporator temperature sensor when it is determined that it can be estimated as the ambient temperature, so there is no evaporator introduction wind temperature sensor However, compressor on / off control is performed according to the situation, and energy saving measures can be taken while maintaining a certain degree of comfort in the cabin, thus realizing a low-cost car air conditioning system for energy saving measures. It is possible to provide an excellent air-conditioning control device for a vehicle, which has never existed before.

The method of estimating the state of the evaporator when the air conditioner switch is turned on can be considered in addition to the methods described in the first and second embodiments. Many things are possible, such as using a temperature sensor.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a relay switching map stored in an internal memory of the microcomputer of FIG. 1;

FIG. 3 is a flowchart showing a control program of the microcomputer of FIG. 1;

FIG. 4 is a flowchart illustrating a control program of a microcomputer according to a second embodiment of the present invention.

5 to 7 are diagrams for explaining a conventional car air conditioner system for energy saving measures.

[Explanation of symbols]

 1 Microcomputer as control means 39 Compressor 41 Evaporator temperature sensor 42 Water temperature sensor 43 Air conditioner switch 45 Magnet clutch relay drive circuit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60H 1/32

Claims (3)

(57) [Claims] An air conditioner switch for stopping driving of an air conditioner, an evaporator temperature sensor for detecting a temperature of an evaporator in the air conditioner, a water temperature sensor for detecting a temperature of an engine cooling water, and a predetermined compressor on / off evaporator. Control means for controlling on / off of the compressor connected to the evaporator in accordance with the temperature via a magnetic clutch relay drive circuit, wherein the control means performs a predetermined method when the air conditioner switch is turned on. A first function of estimating the state of the evaporator and determining whether or not the initial value of the evaporator temperature sensor can be estimated as the ambient temperature of the air conditioner; The evaporator for turning the compressor on / off to a value that is optimal for the value A second function for setting the data temperature,
A third function of setting the compressor on / off evaporator temperature to a predetermined constant value when it is determined that the temperature cannot be estimated as the ambient temperature. 2. The method according to claim 1, wherein the control unit determines whether the water temperature exceeds a predetermined reference temperature based on an output of the water temperature sensor.
The vehicle air conditioning control device according to claim 1, further comprising an evaporator state estimating function for estimating a state of the evaporator when the air conditioner switch is turned on. 3. The control unit estimates the state of the evaporator when the air conditioner switch is turned on based on whether or not the time from when the air conditioner switch is turned off to when it is turned on exceeds a predetermined reference time. 2. The vehicle air conditioning control device according to claim 1, further comprising an evaporator state estimation function.