JPH07186701A - Air conditioner vehicle - Google Patents

Abstract

PURPOSE:To dissolve nonconformity of blowdown temperature becoming a little higher than a target under the condition in which the target value is always varied, in a full reheat type air conditioner for vehicle. CONSTITUTION:When a target blowdown temperature computed by a computing part 21a based on various sorts of sensor signals is varied in the increasing direction, the effect is judged by an increase/decrease judging part 21b, and the target blowdown temperature obtained by computation is given to a correcting part 21c. In the correcting part 21c, because the rising variation speed of the target blowdown temperature is given to a water valve control part 21d in the delayed state by passing the target blowdown temperature through a primary delay filter, the opening speed of the water valve becomes slower than the closing speed for raising the blowdown temperature. Under the condition in which the target blowdown temperature is always varied, because the rising variation speed can be delayed, the rising curve of the blowdown temperature becomes gentle not to rise so much, and the blowdown temperature can be quickly conformed to the target blowdown temperature, even if response is poor at lowering of the target blowdown temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner equipped with an evaporator and a heater core.

[0002]

2. Description of the Related Art As this type of vehicle air conditioner,
An air mix door that adjusts the mixing ratio of the cool air from the evaporator and the warm air from the heater core is provided between the evaporator and the heater core, and the temperature of the blown air is controlled by adjusting the opening of this air mix door. What you have done is well known.

However, this type of device (reheat air mix type) requires an air mix chamber for mixing cold and warm air, and there is a limit to meet the demand for miniaturization. In addition, the left and right outlet temperatures are made uniform,
Requests for equalizing the left and right blown air volume, reducing wind noise, and the like interfere with each other, and therefore a large number of man-hours are required to adjust them. In addition, providing a large number of guides complicates the shape and increases the manufacturing cost.

As a device that can meet the demands for such miniaturization, uniform blowout temperature and blown air volume, and reduction of wind noise, it is possible to use an evaporator without an air mix door. Pass all cold air through the heater core,
There is a method (full reheat type) in which the heating capacity is adjusted with the water valve of the heater core.

As an example of this full reheat type,
For example, there is one disclosed in Japanese Patent Laid-Open No. 34420/1990. That is, as shown in FIG. 4, the air conditioning duct 1
An evaporator 101 is provided on the upstream side in 00, and heater cores 102, 102 are provided on the downstream side so as to block the duct 100. By driving the blower 103, the inside air or the outside air is taken into the duct 100, and the evaporator 100 is introduced. 10
By passing through 1 and each heater core 102, heat exchange for cooling and heating is performed, and temperature-controlled air is blown into the vehicle compartment through the air outlet. Each of the heater cores 102 is provided with a large number of tubes held by fins in a corrugated plate shape with a fine pitch.
5, 105 and the water valves 107, 108 are used to take in the heated engine cooling water, and the piping 10
It is discharged via 6, 106. The air from the evaporator 101 absorbs heat in the process of passing through the corrugated fins, and the heat of the engine cooling water in the tube is taken away to perform heat exchange.
The blowing temperature can be raised by opening 7, 108 and lowered by closing it. Currently, due to factors such as the rise of various control theories and cost reduction of microcomputers, the outlet temperature detected by the outlet temperature sensor is fed back to control the water valve, thereby controlling the outlet temperature to a desired temperature. It is becoming possible.

[0006]

The conventional air conditioner for a vehicle of this type is constructed as described above, but the response in the direction of lowering the blowout temperature is poor due to the heat capacity of the heater core, and the target is always desired. In the situation where the value fluctuates, there is a problem that the outlet temperature is always higher than the target outlet temperature as shown in FIG. This has been a problem when adopting an air conditioner.

The present invention has been made to solve the above problems, and in a full reheat type air conditioner for a vehicle, the blowout temperature is the target when the target value is constantly fluctuating. The purpose is to solve the problem of becoming higher than.

[0008]

According to the present invention, a full reheat type air conditioner is provided with control means for controlling the opening speed of the water valve of the heater core to be slower than the closing speed.

[0009]

In the present invention, the speed at which the water valve is opened when increasing the blowout temperature is controlled to be slower than the speed at which the water valve is closed when decreasing the blowout temperature, resulting in an increase in the blowout temperature. The time constant at time and the time constant at the time of lowering are controlled to be almost the same.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of a vehicle air conditioner according to the present invention. In the figure, reference numeral 1 denotes a duct, which guides the air introduced by the blower 5 from the inside air port 3 or the outside air port 4 selected by the inside / outside air switching door 2 toward the vent outlet 6, the foot outlet 7, and the defrost outlet 8. .
The duct 1 is provided with an evaporator 9, a heater core portion 10, and blowing mode switching doors 11, 12, and 13 in this order in the directions of the outlets 6, 7, and 8.

The evaporator 9 constitutes a cooling cycle together with a compressor, a condenser, a liquid receiver, etc., which are not shown, and is cooled by the operation of this cooling cycle to cool the air from the blower 5 side toward the heater core portion 10. Will be sent. The heater core unit 10 includes the first heater core 1
0a and a second heater core 10b, and the heater cores 10a and 10b are positioned so as to close the duct 1 in parallel with one side close to each other with the partition plate 14 interposed therebetween.
All the air from the evaporator 9 is the heater core 10
Pass a and 10b. The partition plate 14 guides air from the first heater core 10a side toward the vent outlet 6 and air from the second heater core 10b side toward the foot outlet 7 and the defrost outlet 8. Further, the vent outlet 6 is opened by the outlet mode switching door 12 corresponding to the partition plate 14.
The amount of air supplied to the side and the foot outlet 7 and the defrost outlet 8 side is adjusted.

Intake pipes 16 and 1 branched from a pipe 15 extending from a radiator side (not shown) to the cooling water intake ports 10c and 10c of the heater cores 10a and 10b, respectively.
7 are connected to the respective cooling water discharge ports 10d and 10d.
The discharge pipes 18 and 19 are connected to the. Discharge pipe 18, 19
Is connected to a pipe 20 connected to the radiator side (not shown).

A water valve 1 is attached to each of the intake pipes 16 and 17.
6a and 17a are inserted. The water valve 16
The openings of a and 17a are adjusted by actuators 22 and 23 controlled by a microcomputer 21. The microcomputer 21 is input with detection values from a setting device such as room temperature and a blowout mode and various sensors such as an inside air sensor and an outside air sensor, and the vent outlet 6,
The outlet temperature sensors 24 provided at the foot outlets 7,
The detected value of 25 is input, and the water valve 16a,
17a is controlled via the actuators 22 and 23, each of the blowout mode switching doors 11, 12 and 13 is controlled via the actuator 27, and the motor 28 for driving the blower 5 is controlled.

FIG. 2 is a block diagram showing a portion related to the water valve control realized by the microcomputer 21. Reference numeral 21a denotes various sensor signals such as room temperature and set temperature, which are input according to a predetermined arithmetic expression. A target outlet temperature calculation unit for calculating the temperature, 21b is the calculation unit 21a.
Is a target outlet temperature increase / decrease determination unit that determines whether the target outlet temperature output from the target outlet temperature changes in an increasing direction or a decreasing direction. When the target outlet temperature increases, the target outlet temperature is output to the target outlet temperature correcting unit 21c. However, if it decreases, it outputs to the water valve control unit 21d. The target outlet temperature correction unit 21c corrects the target outlet temperature by the first-order lag filter when the target outlet temperature rises and corrects the water valve control unit 21.
It is output to d and acts so as to delay the rate of increase in the target blowout temperature, resulting in a slower speed of opening the water valve. In addition, the water valve control unit 21
In d, the corrected target outlet temperature or the target outlet temperature as obtained by the calculation is input, and the outlet temperature sensor 2
Controlling the opening and closing of the water valves 16a, 17a via the actuators 23, 24 so that the deviation from the blowout temperature fed back from the motors 4, 25 becomes zero, that is, the blowout temperature matches the target blowout temperature. Is. Here, the target outlet temperature calculation unit 21a and the water valve control unit 21d are conventional ones, and a target outlet temperature increase / decrease determination unit 21b and a target outlet temperature correction unit 21c are newly added. The control means 50 of the invention is constructed.

Since how much the opening speed of the water valve is made slower than the closing speed depends on the heat capacity of the heater core and the like, the target outlet temperature correction unit 21c is constructed according to the test results using various sensor signals. By adjusting the time constant of the first-order lag filter to be used, a value suitable for the device can be determined. That is, the time constant for increasing the blowout temperature and the time constant for decreasing the blowout temperature may be the same.

In the above configuration, the detected values of the outlet temperature sensors 24 and 25 provided at the vent outlet 6 and the foot outlet 7 are fed back to the microcomputer 21.
By individually controlling the opening and closing of the water valves 16a and 17a via the actuators 22 and 23, the outlet temperatures of the vent outlet 6 and the foot outlet 7 can be controlled to desired temperatures. In addition, the first heater core 10
a, the air blown out from the second heater core 10b is mainly blown out from the respective vent outlets 6 and foot outlets 7, but the blowout mode switching doors 11, 12, 13 are controlled via the actuator 27. By doing so, the vent outlet 6, the foot outlet 7, and the defrost outlet 8
The amount of air blown from can be controlled.

Here, based on various sensor signals such as room temperature and set temperature input to the microcomputer 21, the target outlet temperature calculated by the target outlet temperature calculator 21a is in the direction of decreasing from the previous calculated value. If it changes,
The target outlet temperature increase / decrease determination unit 21b determines that fact,
The target outlet temperature obtained by calculation is the target outlet temperature correction unit 2
Since it is given to the water valve control section 21d without passing through 1c, the speed at which the water valve is closed in order to lower the blowout temperature has no delay as in the conventional case. On the other hand, when the target outlet temperature calculated by the target outlet temperature calculator 21a changes in a direction to increase with respect to the previous calculated value, the target outlet temperature increase / decrease determiner 21b determines that fact and calculates it. The target outlet temperature obtained by the above is the target outlet temperature correction unit 21.
given to c. In this target outlet temperature correction unit 21c,
By passing the input target outlet temperature through the first-order lag filter, the rate of increase in the target outlet temperature is delayed, and the corrected target outlet temperature is given to the water valve control unit 21d. The speed at which the water valve is opened to raise it is slower than the closing speed. As a result, in a situation where the target outlet temperature constantly fluctuates, as shown in FIG. 3, even if the target outlet temperature (dotted line) obtained by calculation changes as in the conventional example (FIG. 5). Since the rate of change when the target blowout temperature rises is delayed, the rise temperature rise curve becomes gradual and does not rise so much. Therefore, even if the response when the target outlet temperature is lowered due to the heat capacity of the heater core is poor, the outlet temperature can be quickly adjusted to the target outlet temperature.

[0018]

As described above, according to the present invention, the full reheat type vehicle air conditioner is provided with the control means for controlling the opening speed of the water valve of the heater core to be slower than the closing speed. Therefore, it is possible to control so that the time constant when increasing the blow-out temperature and the time constant when decreasing the blow-out temperature are almost the same.
The problem that the outlet temperature becomes higher than the target in the situation where the target value fluctuates is eliminated. As a result, the problem in adopting the full reheat type air conditioner is solved, and the full reheat type can be easily realized, so that advantages such as downsizing of the device and reduction of adjustment man-hours can be enjoyed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a vehicle air conditioner according to the present invention.

FIG. 2 is a block diagram showing a water valve control-related portion of the embodiment.

FIG. 3 is a diagram showing a relationship between a target outlet temperature and an outlet temperature in the embodiment.

FIG. 4 is a configuration diagram showing an example of a conventional device.

FIG. 5 is a diagram showing a relationship between a target outlet temperature and an outlet temperature in a conventional device.

[Explanation of symbols]

 1 duct 5 blower 6 vent outlet 7 foot outlet 8 defrost outlet 9 evaporator 10 heater core portion 10a first heater core 10b second heater core 11 to 13 outlet mode switching doors 16a, 17a water valve 21 microcomputer 21a target outlet temperature calculation portion 21b Target blowout temperature increase / decrease determination unit 21c Target blowout temperature correction unit 21d Water valve control unit 24, 25 Blowout temperature sensor 50 Control means

Claims (1)

[Claims] 1. A blowout temperature of air from the heater core portion is provided on the downstream side of the evaporator by providing a heater core portion through which all the air from the evaporator passes, and adjusting the amount of hot water supplied to the heater core portion with a water valve. In the vehicle air conditioner for controlling the above, the vehicle air conditioner is provided with control means for controlling the opening speed of the water valve of the heater core to be slower than the closing speed.