JPS6210166Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle air conditioner, and more particularly to an improved vehicle air conditioner that can comfortably heat a passenger compartment.

Vehicle air conditioners, especially in winter, are heated by using engine cooling water as a heat source and forcibly feeding air heated by the engine cooling water into the interior of the vehicle using a fan. Therefore, with this type of air conditioner, when the cooling water temperature is low, such as when starting the engine, cold air is instead sent into the vehicle interior.To solve this problem, conventional automatically controlled vehicle In commercial air conditioners, the rotation of the fan is stopped until the cooling water temperature rises to a predetermined value to prevent the above-mentioned cold air from blowing out.

However, this conventional device detects only the engine cooling water temperature and controls the fan based on this, so it is not possible to perform control that follows changes in outside temperature, and in practice it is not possible to control the room temperature comfortably. However, it has the disadvantage that it has little energy saving effect.

In other words, when the outside temperature is relatively high, even if the engine cooling water temperature is lower than the temperature set by the conventional device, warm air suitable for heating the passenger compartment can be blown sufficiently; When the outside temperature is low, the occupants may feel cold air even when the cooling water temperature is at the conventional setting value, and it has been impossible to perform such detailed control in the past.

The present invention was developed in view of the above-mentioned conventional problems, and its purpose is to control the warm air blown into the passenger compartment when starting the engine in relation to the outside temperature,
An object of the present invention is to provide an improved vehicle air conditioner that can achieve a comfortable heating effect and an energy saving effect.

In order to achieve the above object, the present invention provides a vehicle air conditioner that uses a fan to forcefully feed air heated using engine cooling water as a heat source into a vehicle interior. A sensor, an outside air sensor that detects outside air temperature, and a microcontroller that predicts the temperature of warm air that will be blown into the cabin based on the engine cooling water temperature and outside air temperature, and controls the rotation of the fan when this predicted temperature is above a predetermined value. including the computer, and even if the engine coolant temperature is high to some extent, if the outside temperature is low and the hot air temperature is not high,
The system stops and controls the rotation of the fan to prevent cold air from hitting the occupants, and even when the cooling water temperature is relatively low, if the outside temperature is high enough to blow out hot air, the fan is driven to rotate. It is characterized by quickly providing a feeling of heating to the occupants.

Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a schematic configuration of an air conditioner according to the present invention, in which an inside air intake 12 and an outside air intake 14 are provided on the inlet side of a ventilation duct 10. 14 is selectively switched and controlled by a damper 16, and the damper 16 is automatically switched and driven by a servo motor or other actuator.

On the outlet side of the ventilation duct 10, there are a heater outlet 18, a vent outlet 20, and a defroster outlet 2.
The heater outlet 18 and the vent outlet 20 are selectively switched and controlled by a switching damper 24, and the defroster outlet 22 is controlled to open and close by an opening/closing damper 26. In the embodiment, dampers 24 and 26 are driven and operated by a vehicle occupant via a lever or the like, but of course each of these dampers can also be automatically driven by a motor or solenoid.

A fan 30 rotatably driven by a motor 28 is provided on the inlet side of the ventilation duct 10, and a fan speed controller 32 controls the desired air volume to circulate the air inside the vehicle. Fresh air taken in from the outside flows through each outlet 18, 2.
It is fed into the passenger compartment from 0 and 22.

Further, an evaporator 34 forming a heat exchanger for cooling is provided in the ventilation duct 10, and constitutes a refrigeration cycle together with a compressor, a condenser, etc. (not shown), and cools the air sent by the fan 30. A cooler is formed.

Furthermore, an air mix type temperature control mechanism is provided in the ventilation duct 10 downstream of the evaporator 34, and this temperature control mechanism includes a heater core 36 and an air mix damper 36. is introduced to perform the desired heating action, and the air mix damper 38
By controlling the opening degree using the actuator 40, a mixture of cold air and hot air is achieved, and a desired blowing temperature into the vehicle interior can be controlled.

The aforementioned damper 16 and air mix damper 38
Each actuator that drives the fan 30 is driven and controlled by a microcomputer 42, and the microcomputer 42 controls the rotation of the fan 30 and the operation of the compressor of the cooler based on control signals from various sensors.

In the embodiment, the various sensors include a water temperature sensor 44 that detects the engine cooling water temperature and an inside air sensor 46 that detects the vehicle interior temperature.
The present invention is characterized by being provided with an outside air sensor 48 that detects the outside temperature, and in the embodiment, a solar radiation sensor 50 that detects the amount of solar radiation is also provided. Outside air sensor 4 in Figure 1
8 is provided at any location outside the vehicle, but as shown in FIG. 1, it is also preferable to provide an outside air sensor 48a on the exit side of the evaporator 34 in the ventilation duct 10 as an outside air sensor. The outputs of the various sensors are supplied to the microcomputer 42, and the computer 42 is also supplied with a desired vehicle interior temperature signal from a temperature setting device 52.

Fig. 2 shows the control action of the vehicle air conditioner shown in Fig. 1, including the hot air blowing operation at the time of starting the engine according to the present invention. Explain the action.

When the apparatus starts, the computer 42 reads input data from each sensor and calculates a target air outlet temperature T _AO for controlling the vehicle interior temperature to a desired set temperature T _set . This target outlet temperature T _AO is the set temperature T _set , the outside air temperature To measured by the outside air sensor 48, and the vehicle interior temperature measured by the inside air sensor 46.
Tr and the amount of solar radiation St from the solar radiation sensor 50, and is calculated within the computer 42 _.
=K ₁ T _set −K ₂ To−K ₃ Tr−K ₄ St＋C(K ₁ , K ₂ ,
K ₃ , K ₄ , and C are constants).

Once this target outlet temperature _TAO is determined, in this embodiment, depending on the size of the heating load at this time, the fan control is performed as in the conventional method, or the control at the time of engine starting, which is a feature of the present invention, is performed. For this purpose, the target blowout temperature T _AO
is compared with a predetermined heating load value a. In other words, the target outlet temperature _TAO is equal to the predetermined heating load value a.
If it is smaller, it means that the heating load is small, that is, the temperature inside the vehicle is relatively large and there is no need for a very high temperature blowing action. In such a case, only conventional fan speed control can be used without the need for detailed control of the blowout temperature according to the present invention, which will be described later. It is done.

That is, the computer 42 controls the actuator 40 to drive the air mix damper 36 so that the temperature of the air blown inside the vehicle becomes the target air temperature _TAO . At the same time, the computer 42 executes fan speed control based on the _TAO shown in FIG. 2, and operates the fan speed controller 32. The fan speed controller 32 includes a variable resistor or a pulse speed controller as in the conventional case, and controls the fan 30 based on a control signal from the computer 42.
The fan motor 38 is controlled so that the fan motor 38 is rotated at the optimum air blowing speed.

On the other hand, if the target outlet temperature T _AO is the predetermined heating load value a
If it is larger, it indicates that the heating load is large, ie, during air control in winter, and the engine is normally starting, so the air conditioner of the present invention works effectively.

The present invention is characterized by controlling the heating effect at the time of starting the engine in winter in conjunction with not only the engine cooling water temperature but also the outside air temperature. Even if it is high to a certain extent, the actual blowing temperature will be lower, reliably preventing cold air from hitting the occupants.
Furthermore, when the outside temperature is high to a certain extent, the actual blowout temperature will be high even when the cooling water temperature is relatively low, so air is blown, making it possible to quickly provide a feeling of heating to the occupants.

In order to carry out the control according to the present invention, when the heating load is large, the computer 42 controls the water temperature sensor 4.
The above-mentioned blowout temperature T _AW is determined from the cooling water temperature from 4 and the outside air sensor 48 using the following formula: T _AW =K ₁ T ₀ +K ₂ T _w .

(K ₁ and K ₂ are constants, generally K ₂ =1-K ₁ ) Then, the blowing temperature T _AW is compared with a predetermined comparison value to perform on/off control of the fan 30. Since this comparison value has hysteresis in the on-off control of the fan 30, the on-comparison value b ₁ and the off-comparison value differ by a predetermined hysteresis width.
_b2 , and these comparison values are set, for example, to about 30 to 40°C for the on comparison value _b1 and about 25 to 35°C for the off comparison value _b2 .

As _is clear from _FIG .
0 is turned on and the desired speed control is performed.

Therefore, when starting the engine, the blowing action is not performed until the actual predicted blowing temperature T _AW reaches a predetermined value, and it is possible to prevent cold air from being applied to the occupant.

When the engine water temperature etc. decreases, the air outlet temperature T _AW becomes smaller than the previous on comparison value b ₁ , but in this case, in order to provide hysteresis, the air outlet temperature T _AW is further reduced to the off comparison value b ₂ . The fan 30 is turned off and the blowing action is stopped only when the blowing temperature _TAW becomes lower than the off comparison value _b2 .

By implementing the above-mentioned control action, even when the heating load is large when the engine is started, it is possible to quickly give a feeling of heating to the occupants and to efficiently utilize the engine cooling water.

In the embodiment described above, the on-off comparison value b
is a fixed value, but it is also possible to change this in conjunction with the outside temperature.

Further, in this embodiment, when the target air outlet temperature T _AO is larger than the predetermined value a, the predicted value T _AW of the actual air outlet temperature is
However, instead of the target outlet temperature _TAO , it may be determined whether the outlet is in the heater mode, and in the case of the heater mode, the predicted value _TAW of the actual outlet temperature may be calculated.

As explained above, according to the present invention, by controlling the temperature jetting effect at the time of engine startup by linking not only the conventional cooling water temperature but also the outside air temperature, the engine cooling water temperature can be controlled even when the outside air temperature is low and the engine cooling water temperature is high to some extent. It is also possible to reliably prevent cold air from hitting the occupants even when the actual blowout temperature is low.
Furthermore, even when the cooling water temperature is relatively low, if the outside temperature is high enough to increase the actual blowout temperature, air blowing can be started quickly to quickly provide a feeling of heating to the occupants.

That is, according to the present invention, it is possible to perform control to provide a feeling of heating as quickly as possible without blowing cold air to the occupant, and it is also possible to contribute to energy saving.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a preferred embodiment of a vehicle air conditioner according to the present invention, and FIG. 2 is a flowchart showing the control operation of FIG. 1. 10... Ventilation duct, 30... Fan, 36...
...Heater core, 42...Microcomputer,
44...Water temperature sensor, 48, 48a...Outside air sensor, 52...Temperature setting device.

Claims (1)

[Scope of Claim for Utility Model Registration] In a vehicle air conditioner that uses a fan to forcefully feed air heated using engine cooling water as a heat source into a vehicle interior, a water temperature sensor that detects the temperature of the engine cooling water and an external an outside air sensor that detects the air temperature; a microcomputer that predicts the temperature of warm air blown into the vehicle interior based on the engine cooling water temperature and the outside air temperature, and controls the rotation of the fan when the predicted temperature is above a predetermined value; Even if the engine coolant temperature is high to some extent, if the outside temperature is low and the hot air temperature is not high,
The system stops and controls the rotation of the fan to prevent cold air from hitting the occupants, and even when the cooling water temperature is relatively low, if the outside temperature is high enough to blow out hot air, the fan is driven to rotate. A vehicle air conditioning system that is characterized by quickly providing a feeling of heating to the occupants.