JPS64325Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an air conditioning control device for an automobile, and particularly to an air conditioning control device for an automobile that makes full use of a microcomputer to control the air blown by a blowing fan during heating.

BACKGROUND ART Conventionally, air conditioning control devices for automobiles have been fully automated by the introduction of microcomputers, and the air blown into the passenger compartment during heating is also controlled by arithmetic processing according to a control program. In this case, the air blown into the vehicle interior is sent by a fan through a heater core disposed in a ventilation duct that constitutes the vehicle interior air conditioning system. Since the heater core is configured to guide heated water that forms a heating heat source by transmitting heat generated by engine operation, the temperature of the heated water controls the temperature of the blowing air. . For this reason, conventional blower fan control uses a water temperature sensor to detect the temperature of the heated water being guided to the heater core provided on the leeward side of the cold/hot air mixing door, and when the output of this sensor reaches a predetermined value, In other words, in anticipation of the end of so-called warm-up, the cold/hot air mixing door is fully opened and the blower fan is driven.

However, with a configuration that performs control focusing only on the temperature of the heated water, the temperature of the blowing air does not necessarily follow the temperature of the heated water due to engine conditions, heat capacity of the heater core, etc. For example, if the fan motor of the ventilation fan is immediately driven at high speed in response to the output of the water temperature sensor at the start of heating, the temperature of the blown air will not reach the appropriate temperature, which may cause discomfort to the occupants. In particular, during the severe cold of winter, if the blower fan blows strong wind at a temperature below the optimum temperature, there is a risk that the discomfort will be further exacerbated and the heating effect will be diminished.

In addition, when the engine is turned off in cold weather, if the temperature of the coolant has not dropped sufficiently but the temperature around the heater core has dropped sufficiently, if you start the engine again and switch to heater mode, the coolant will cool down. Because the temperature was not low enough, the air conditioning control system, which detects the temperature of the cooling water and blows air, had a problem in that the blower fan rotated at high speed, blowing cold air strongly against the occupants.

This idea was created by focusing on these conventional problems, and the drive speed of the blower fan is controlled according to the warm-up stage of the heater core, so that a comfortable heating effect can be obtained at all times. The purpose is to provide an air conditioning control device for automobiles. In order to achieve this purpose, this invention includes a heater core that is installed in a vehicle interior air conditioning system and that guides warm water heated by the operating heat of the engine to form a heat source for heating, and a heater core that is installed near the heater core. a blowout temperature sensor that detects the temperature of the blowout air sent to the passenger compartment by the blower fan via the blower fan; and the blowout temperature sensor is capable of detecting the temperature of the blowout air and does not make the occupants feel the blowing air. an ultra-low-speed drive means for rotating the blower fan at an ultra-low speed lower than the low-speed rotation; and an ultra-low-speed drive means for rotating the blower fan at an ultra-low speed when heating is started in the heater mode to rotate the blower fan at an ultra-low speed; holding means for maintaining low speed rotation;
temperature setting means for setting the temperature inside the vehicle; target temperature calculation means for calculating the target temperature of the outlet air based on the temperature set by the temperature setting means; When the temperature detected by the outlet temperature sensor is lower than the target temperature calculated by the target temperature calculation means, the holding means is left in operation, and when the detected temperature reaches the target temperature, the holding means is operated. furthermore, when the temperature detected by the blowout temperature sensor is lower than a predetermined temperature, the blower fan is held at low speed rotation, and when the detected temperature reaches the predetermined temperature, the blower fan is set to the rotation speed under normal control. The structure is such that a comparison means is provided.

This invention will be explained below based on the drawings.

1 to 6 illustrate one embodiment of this invention, and in the figures, reference numeral 1 indicates the cabin of an automobile, and in this cabin 1 there is a ventilation duct 2 constituting the cabin air conditioning system. An internal/external air switching door 3 is provided at an internal/external air intake port 2A, which is attached in communication with one another and which is one end of the ventilation duct 2, for switching between intake of air from the outside Q of the vehicle interior or the inside R of the vehicle interior. The interior side R of the vehicle interior and the communication hole S provided in the vehicle interior 1 are communicated with each other through a pipe or the like. Further, in the ventilation duct 2, ventilation fans 4 are provided at predetermined intervals on the vehicle interior side of the inside/outside air switching door 3, and furthermore, ventilation fans 4 are provided at predetermined intervals on the vehicle interior side through an evaporator 5 for cooling and heating. A gas mixing door 6 is provided. A heater core 7 is provided at the other end of the ventilation duct 2 at a portion facing the vehicle interior 1 on the vehicle interior side of the cool/hot air mixing door 6. Hot water that is heated by transmitting the operating heat of the engine is guided to the heater core 7, and thus the heater core 7 forms a heat source for heating. In addition, the inside/outside air switching door 3
can be opened and closed by, for example, a negative pressure drive type actuator 8 for switching between inside and outside air, and the blower fan 4 can be freely controlled in terms of the amount of air blown, that is, the rotational speed of the fan, by a blower fan control actuator 9 composed of an electric circuit. It is becoming. Further, the cold/hot air mixing door 6 can be opened and closed by, for example, a negative pressure drive type actuator 10 for adjusting the door opening degree.

Further, a room temperature sensor 11 for detecting the temperature Ti inside the vehicle interior is attached to the vehicle interior 1 at an appropriate position, an outside temperature sensor 12 for detecting the temperature To of the outside air is attached to the outside of the vehicle body, and For example, in the cowl top grille part there is a solar radiation sensor 13 for obtaining an output Z according to the amount of solar radiation entering the vehicle interior.
is installed. A blowout temperature sensor 15 is attached to a portion of the heater core 7 facing the passenger compartment 1 to detect the temperature Tt of the blowing air sent to the passenger compartment 1. Each of these sensors 11, 12, 13,
14 and 15 are connected to an analog-to-digital (A-D) converter 16, which facilitates signal processing by the microcomputer 17. In addition, the microcomputer 17
A temperature setting unit 18 generates a digital signal for setting the room temperature inside the vehicle to a desired temperature Ts.
(temperature setting means) is connected, and the analog output of this temperature setting section 18 is supplied to the aforementioned A-D converter 16, digitized, and processed by the microcomputer 17.

The aforementioned actuator 8 for switching between inside and outside air, the actuator 9 for controlling the blower fan, and the actuator 10 for adjusting the door opening degree are controlled by the microcomputer 17 according to a predetermined air conditioning control program for arithmetic processing.

Next, to explain the microcomputer 17 in detail, the room temperature sensor 1 that has passed through the A-D converter 16
1 and the outputs of the outside temperature sensor 12 are supplied to a determination calculation circuit 19, which determines whether or not heating is required. The output of this arithmetic circuit 19 is supplied to a mixture door opening degree arithmetic circuit 20, so that the cold/hot air mixture door 6 can be fully opened when heating is required (in heater mode).

Further, the output of the judgment calculation circuit 19 is supplied to a drive circuit 22 connected to the blower fan control actuator 9, and the output of a comparison circuit 23 (comparison means) is supplied to this drive circuit 22 (ultra-low speed drive means). .

In addition, the determination calculation circuit 19 operates the drive circuit 22 to rotate the blower fan 4 at a very low speed when in the heater mode, and has a function as a holding means for keeping the blower fan 4 at a very low speed. ing.

By the way, here, ultra-low speed rotation means sending a breeze from the heater core into the atmosphere around the blowout temperature sensor 15, so that the blowout temperature sensor 15 can detect the temperature of the blowout air, and the passenger can feel the blowing air. This is the rotational speed of the blower fan 4 that never occurs.

The comparator circuit 23 is supplied with the outputs of the outlet temperature sensor 15 and the target room temperature calculation circuit 24 . The target room temperature calculation circuit 24 calculates the target temperature of the blowing air based on the temperature set by the temperature setting section 18 and the temperature of each sensor 12, 13 inputted via the A/D converter. The comparison circuit 23 compares the detected temperature detected by the outlet temperature sensor 15 with the target temperature calculated by the target room temperature calculation circuit 24, and stops the operation of the drive circuit 22, which will be described later, when the detected temperature reaches the target temperature. The drive circuit 26 is activated. The drive circuit 22 controls the actuator 9 for controlling the blower fan so that the blower fan is rotated at a very low speed lower than the low speed rotation as shown in FIG. 3 at the start of heating. Therefore, the drive circuit 22 controls the blower fan control actuator 9 to first maintain the blower fan 4 in a very low speed driving state lower than the normal minimum rotational speed in the heater mode. This ultra-low speed driving state continues until the output of the outlet temperature sensor 15 in the comparison circuit 23 exceeds the output of the target room temperature calculation circuit 24 (corresponding to the temperature θ ₁ of the outlet air). Furthermore, the output of the comparison circuit 23 is
When the output of the blowout temperature sensor 15 exceeds a predetermined blowout air temperature θ ₂ and reaches the corresponding output, the blower fan 4 is rotated to the normal minimum rotation speed. The blower fan control actuator 9 is controlled to maintain the speed drive state.

Note that the target room temperature calculation circuit 24 is connected to the outside temperature sensor 1.
2. In response to the outputs of the solar radiation sensor 13 and the temperature setting unit 18, a target temperature in the vehicle interior, in particular, a target value _TSL of the temperature at the feet of the passenger is determined. Further, after the temperature of the blowing air exceeds the predetermined value θ ₂ , normal air conditioning control is performed, and for this reason, the blower fan control actuator 9 is controlled according to the target foot temperature T SL and the blower fan is controlled in accordance with the target foot temperature T _SL. 4 is driven between a low speed drive state and a high speed drive state. Furthermore, the output of the target room temperature calculation circuit 24 is supplied to the actuator 8 for the inside/outside air switching door via the drive circuit 25, so that the opening/closing of the inside/outside air switching door 3 is controlled.

Next, the operation of the air conditioning control device will be explained according to a flowchart.

When an air conditioning control switch (not shown) is turned on and the microcomputer 17 is powered on while driving a car, the air conditioning control program starts arithmetic processing from the start step 100. Next, the process moves to an initial setting routine 101, where the register circuit, counter circuit, latch circuit, etc. of the microcomputer 17 are set to the initial setting state necessary for execution of arithmetic processing, and preparations are made to read input data from the outlet temperature sensor 15, etc. Complete. Once this initial setting has been made, the routine moves to a blower fan start calculation routine 102, where rotation control calculations for the blower fan 4 are performed. Then, based on the result of this calculation routine 102, the routine proceeds to various air conditioning control calculation routines 103 for performing normal air conditioning control. In addition, calculation routine 1
03 is repeated at a predetermined cycle.

To explain the details of the ventilation fan start calculation routine 102, in the process 104 following the initial setting routine 101, the target foot temperature T _SL is K ₁ T _S +
Calculated according to the formula K ₂ Ta + K ₃ Z. Here T _S
is the set temperature, Ta is the outside temperature, Z is the amount of solar radiation,
K ₁ , K ₂ , and K ₃ are each constants. Then, in judgment 105 following process 104, a judgment is made as to whether or not to set the heater mode, and this judgment result is affirmative.
If YES, the process proceeds to step 106 and a command to maintain the blower fan 4 at a very low rotation speed is obtained.
As a result, the drive circuit 22 is operated to rotate the blower fan 4 at a very low speed, and the blower fan 4 is maintained in a state of rotation at a very low speed. Because the air blower fan 4 rotates at an extremely low speed, the occupants do not feel the air being blown, so when starting the engine in cold weather, or when the cooling water temperature has not yet dropped sufficiently, the temperature around the heater core has dropped sufficiently. This prevents cold air from blowing strongly against the occupants when the engine is restarted.

Next, the process proceeds to decision 107, where it is determined whether the blown temperature θ of the vehicle interior 1 exceeds the target foot temperature _TSL . If the result of this determination is negative (NO), that is, if the blown temperature θ has not reached the target foot temperature _TSL , the process returns to step 106 to maintain the rotation of the blower fan 4 in the ultra-low speed drive state.
If the result of decision 105 is affirmative YES, the process proceeds to decision 108 where it is determined whether or not the blowing temperature θ exceeds a predetermined value θ ₂ °C. If the result of this decision is negative NO, i.e., the blowing temperature θ has not reached the predetermined value θ ₂ , the process proceeds to step 109 where a command is issued to maintain the blower fan 4 in a low speed operation state. On the other hand, if the result of decision 108 is affirmative YES, the process proceeds to various air conditioning control calculation routines 103 where normal air conditioning control is performed. Furthermore, if the result of decision 105 is negative NO, i.e., the heater mode is not selected, the process immediately proceeds to various air conditioning control calculation routines 103.
transition to.

In addition, in this example, the temperature θ of the blowing air
When the fan 4 does not reach a predetermined temperature θ ₂ , that is, in a warm-up state, the fan 4 is not operated normally, but is driven at two low speeds (low speed or ultra-low speed) to reduce the burden on the occupants when starting the fan 4. Although the aim is to eliminate discomfort as much as possible, it goes without saying that it is also possible to drive at three or more low speeds in order to further enhance the effect.

As explained above, according to this invention, for example, if the heater core is not sufficiently warmed up during heater mode in winter,
In other words, when heating starts, the temperature of the blowing air does not change in response to changes in the temperature of the cooling water, or when the temperature of the blowing air is still low and the temperature of the cooling water rises rapidly when the engine starts. Even if
Regardless of the temperature of the cooling water, the holding means operates the ultra-low speed drive means to rotate the blower fan at an ultra-low speed,
Since the blower fan is kept rotating at an extremely low speed, there is no chance of cold air blowing strongly against the occupants.

In addition, when the engine is turned off in cold weather, the temperature of the cooling water has not decreased sufficiently, but if the temperature around the heater core has decreased sufficiently, when the engine is started again and switched to heater mode, the cooling water Regardless of the temperature of Since the air blowing is controlled, the occupants will always receive the low-speed wind first, and the occupants will not be hit with strong cold air, achieving a comfortable heating effect not only in the initial stage but also in general. be able to.

In addition, if the cabin temperature is set using the temperature setting means, the rotation speed of the blower fan will be automatically controlled according to the temperature of the blowing air. This eliminates the trouble of changing the rotational speed one by one, and therefore has the advantage of allowing safe driving without interfering with driving operations.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an air conditioning control device illustrating an embodiment of this invention, Fig. 2 is a block diagram illustrating an electric circuit in the air conditioning control device of Fig. FIG. 4 is a flowchart explaining the overall flow of the microcomputer control program that operates the air conditioning control device; FIG.
It is a main part flowchart explaining the more detailed control program of the figure. 1... Vehicle interior, 2... Ventilation duct, 4... Ventilation fan,
7... Heater core, 9... Actuator for blower fan control, 15... Outlet temperature sensor, 19... Judgment calculation circuit, 22, 26... Drive circuit, 23... Comparison circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] A heater core installed in a vehicle interior air conditioning system that guides heated water heated by the operating heat of the engine to form a heat source for heating; a blowout temperature sensor that detects the temperature of the blowing air sent into the passenger compartment by the blower fan; and a low-speed rotation sensor that allows the blowout temperature sensor to detect the temperature of the blowout air and that does not make the occupants feel the blowing air. ultra-low-speed drive means for rotating the blower fan at an ultra-low speed lower than the above; and when in heater mode, the ultra-low-speed drive means is actuated to rotate the blower fan at an ultra-low speed when heating starts, and the blower fan is rotated at an ultra-low speed. temperature setting means for setting the temperature inside the vehicle; and target temperature calculation means for calculating the target temperature of the outlet air based on the temperature set by the temperature setting means. The temperature detected by the outlet temperature sensor is compared with the target temperature calculated by the target temperature calculation means, and if the temperature detected by the outlet temperature sensor is lower, the holding means is left in operation, and the detected temperature is lowered. When the target temperature is reached, the holding means is released; furthermore, when the temperature detected by the blowout temperature sensor is lower than a predetermined temperature, the blowing fan is held at low speed; and when the detected temperature reaches the predetermined temperature, the blowing fan is released. An air conditioning control device for an automobile, characterized in that it is provided with comparison means for setting the fan to a rotational speed under normal control.