JPS6047718A - Controller for air conditioner for car - Google Patents

Abstract

PURPOSE:To improve comfortableness by judging the transition state in heating from the heating capacity of a heater and decreasing the heating effect during transition state, in an air conditioner equipped with the heater which utilizes engine cooling water. CONSTITUTION:The information of a car-interior temp. setting resistance 16, room temp. sensor 17, and an outside air temp. sensor 18 is input into a temp. controlling circuit 15 to control an air mix damper AM. The heating capacity signal of a heater which is outputted by a cooling-water temp. sensor 22 is compared with the standard values which are determined by partial voltage resistances 23-26 by comparators 27-29, and the heating capacity is judged stepwise, and each high level signal is output according to water temp., for example, at 80 deg.C or more, 50 deg.C or more, and 30 deg.C or more. Therefore, when the water temp. is 80 deg.C or less, the output of the comparator 27 turns ON a transistor 31, and a correction resistance 32 is connected to a room temp. sensor 17, and the detection temp. 17 is increased apparently. Therefore, the air mix damper AM is set in the direction of decrease of heating effect, and comfortableness can be improved.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a heater using engine cooling water as a heat source and a control applied to a car air conditioner having a temperature control member for adjusting the heating effect in the heater. Regarding equipment.

〔background〕

Car air conditioners with this type of temperature control mechanism are well known.For example, a type that uses a temperature control member to change the mixing ratio of heated air passing through a heater and unheated air;
In other words, a configuration having a so-called air mix damper is generally known.

In such a car air conditioner, a control device that automatically controls the temperature of the blown air controls the operation of a temperature adjustment member (e.g., an air mix damper) based on at least a detection signal detected by a room temperature sensor, thereby controlling the temperature of the heater. Temperature control means are provided for adjusting the heating effect at the temperature.

In general, a room temperature sensor should accurately sense the room temperature.
Furthermore, the installation position is determined in consideration of ease of installation. The number of room temperature sensors is generally one, and may be more than one if necessary.

In the automatic temperature control device configured as above,
There is a problem in that the room temperature sensor does not always produce a detection signal that matches the temperature sensation of the occupant. In other words, the room temperature sensor does not directly detect only the temperature of the air blown from the car air conditioner, nor does it only detect the temperature of the air close to the occupants, but is installed to detect the representative temperature inside the vehicle. When performing rapid heating, there is a considerable delay before the heating effect is actually detected, and this results in the temperature control member being held at a higher temperature than necessary, which is harmful to the occupants. There are problems that cause discomfort such as flushing.

(Objective of the Invention) It is an object of the present invention to solve the above-mentioned problems.

For this reason, the present invention determines whether or not the rapid heating is in a transient state as described above, and when the result of this determination indicates that the temperature control system is in a steady state, control is The problem to be solved is to make the response speed of the system appear as described above.

[Structure of the invention]

Therefore, the present invention determines whether or not a transient state is occurring based on the heating capacity of the heater, and when this heating capacity falls within a range that gives an excessive thermal sensation to the occupant, the temperature control means is activated. The above-mentioned problem is solved by providing a means for reducing the heating effect of the heater regulated by the temperature regulating member.

In the embodiment described below, in order to reduce the heating effect of the heater, a correction resistor is connected to the room temperature sensor so that the room temperature sensor produces a detection signal corresponding to an apparently higher temperature. There is. Since the correction may be any correction that does not affect the operation of the temperature regulating member, the means for realizing the correction is not limited to the configuration of the embodiment.

In addition, in the following example, the determination of a transient state based on the heating capacity is based on whether the engine cooling water temperature is below the set value. This is when the cooling water temperature is considerably high. Therefore, when determining a transient state, a predetermined temperature range may be determined by adding a lower limit set value.

The detection signal of the heating capacity is advantageous in that it can be used not only for reducing the heating effect of the heater described above but also as a signal for reducing the flow rate of air blown into the passenger compartment.

〔Example〕

The illustrated embodiment represents an electrical circuit to which the present invention is applied. Among the components of the car air conditioner to which the present invention is applied, the heater and the air mix damper, which is a temperature control member, may be well-known components, so their explanation will be omitted. Also,
Among the components in the accompanying drawings, those that are publicly known and have only a weak relation to the present invention will only be given their names.

The battery 1 is connected to a blower motor 4 through the contacts of a circuit breaker 2 and a heater relay 3, and is further connected to a compressor drive crank (not shown) via a manually operated air conditioner switch 5 and an evaporator low pressure switch 6 (not shown). - Connected to the notch 7 and the engine speed increase device 8.

When the contacts of the ignition switch 9, blower switch 10, and starter cut relay 11 are closed, the heater relay 3 closes its contacts to supply power to the blower motor 4 and others. The contacts of the starter cut relay 11 open only when the starter switch 12 is turned on.

The blower motor 4 is connected in series with the blower resistor 13,
The rotation speed is determined according to the resistance value of the plow register selected by the plow switch 10. Further, in the blower motor 4, only when the follower switch 10 selects the automatic motor contact point AUTO, the resistance value of the blower register 13 is selected by the program switch 14, and the blowing air flow rate is automatically determined.

15 is a temperature control circuit. This circuit 15 has as input a setting resistor 16 for setting the desired temperature inside the vehicle, a room temperature sensor 17, and an outside temperature sensor 18, and outputs an output signal that increases or decreases the position of the air mix damper/'AM according to the combined resistance of these. is generated and applied to the electromagnetic control valve pair 19 and 20. Note that the opening degree of the air mix damper is fed to the input of the control circuit 150 by the potentiometer 21.

The program switch 14 is adapted to move in conjunction with the opening degree of the air conditioner.

Reference numeral 22 denotes an engine cooling water temperature sensor, which generates an electric signal corresponding to the temperature of the heater, that is, the heating capacity of the heater. This sensor consists of a thermistor, the terminal voltage of which decreases with increasing heating capacity of the heater. This terminal voltage is compared by comparators 27, 28, 29 with three reference values defined by voltage dividing resistors 23-26, producing an output signal at the output terminal of the comparator group which determines the heating capacity step by step. In this embodiment, the output signal of the comparator 29 becomes a high level when the water temperature exceeds 30°C, the output signal of the comparator 28 becomes a high level when the water temperature exceeds 50°C, and the output signal of the comparator 27 becomes a high level when the water temperature exceeds 80°C. It is set so that it becomes high level when it exceeds ℃.

The output of the comparator 27 is connected to a switching transistor 31 via an inverter 30, and while the water temperature is below 80° C., the transistor 31 is turned on and a correction resistor 32 is connected to the room temperature sensor 17.

Connecting the correction resistor 32 corresponds to an apparent increase in the detected temperature of the room temperature sensor (thermistor having a negative temperature coefficient) 17.

According to this embodiment, the air mix damper AM is moved in the direction of reducing the heating effect by an amount corresponding to the resistance value of the correction resistor during a period when the water temperature is low. As a result, when the engine water temperature gradually rises after the engine starts,
Even if the room temperature sensor 17 responds slowly to a rise in the temperature of the blown air, the air mix damper AM can be pulled back due to the effect of the correction resistance, so that excessively heated air is not directed to the vicinity of the occupant. There is no.

The output of comparator 28 is connected to warm-up relay 33. This relay 33 is a normally closed type, and the water temperature is 50°C.
The contact is opened when the temperature is below ℃.

Therefore, the follower register 10 is set to automatic mode AUTo.
When the water temperature is 50° C. or lower, all of the plow registers 13 are connected to the plow motor 10, and the rotation speed of the plow motor 10 is forcibly set to the lowest value.

The output of comparator 29 is connected to warm-up cut relay 34. This relay 34 is a normally closed type, and its contacts are also connected in series with a manually operated heater mode switch 35.
When the automatic mode AUTO is selected, the heater relay 3 is not energized and the air blowing is stopped.

Note that the heater mode switch 34 may be operated in conjunction with a manually operated blowout mode controller, or may stop or reduce the air volume and correct the air mix damper opening depending on the cooling water temperature only in the heater mode. This is to ensure that this is carried out.

Although one embodiment of the present invention has been described above, the above-mentioned modifications can be made according to practical needs. Further, in the above configuration, by adding an AND circuit so that the transistor 31 is driven by the AND logic of the output of the comparator 28 and the output of the inverter 30, the temperature adjustment can be corrected from 50° C. The heating may be carried out within a range of 80°C.

[Brief explanation of the drawing]

The accompanying drawings are electrical wiring diagrams showing one embodiment of the present invention. 15... Temperature control circuit, 17... Room temperature sensor, 22
...Cooling water temperature sensor that responds to heating capacity, 27...
Comparator, 31...transistor, 32...correction resistor. Agent Patent Attorney Takashi Okabe

Claims (1)

[Claims] In a control device applied to a car air conditioner that has a heater using engine cooling water as a heat source and a temperature adjustment member for adjusting the heating effect in this heater, the temperature adjustment member is operated based on at least a detection signal from a room temperature sensor. temperature control means for controlling the heating capacity of the heater, and heating in the heater that is adjusted by the temperature adjustment member by acting on the temperature control means when the heating capacity of the heater is within a predetermined range; A car air conditioner control device comprising: means for reducing the effect.