JPH04257718A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To perform the warm-up control decreasing the blowout air quantity when the temperature of a heater is low by using the signal of a blowout temperature sensor without directly measuring the temperature of the heater. CONSTITUTION:A blower motor is intermittently driven for several seconds each when the blowout temperature is low during the warm-up control, and a blowout temperature sensor monitors the temperature of a heater without giving the cold air feeling to the crew.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is a so-called vehicle air conditioner that controls the blowout air volume using a blowout temperature signal when warm air is required at startup and the heat source is not sufficiently heated. The present invention relates to a vehicle air conditioner having a warm-up function.

0002

2. Description of the Related Art Conventionally, in a vehicle air conditioner, Japanese Patent Laid-Open No. 60-33121 discloses a control method when the outlet temperature is below a set value in the heater mode. This method determines the blower air volume according to the engine water temperature. When the water temperature is low during warm-up, the air volume is set to low or OFF, and the air volume is increased as the water temperature rises. If this is done with a system using an outlet temperature sensor, the air volume will be turned off.
If left as is, even if the water temperature rises, the outlet temperature sensor will not be able to detect the fact that the water temperature has risen. Therefore, if the air volume is set to a certain level (weak) when the water temperature is low so that the air outlet temperature sensor can detect a rise in water temperature, cold air will come out from the heater outlet, which will cause a problem in terms of feeling.

0003

[Problem to be Solved by the Invention] In a vehicle air conditioner using an outlet temperature sensor, when warm air is required at startup and the heat source is not sufficiently heated, the outlet temperature sensor is used to control the outlet air volume. do it like this. At this time, the water temperature sensor is not used. It is an object of the present invention to provide an air conditioner for a vehicle that does not generate cold air even with this configuration and can provide a satisfying feeling.

0004

[Means for Solving the Problems] As shown in FIG. 1, the present invention blows air blown out from a blower motor (11) through at least an evaporator (12) and a heater (13) from a predetermined outlet. A control unit (7) that controls the rotational state of the blower motor (11) according to signals from various sensors, and a control unit (7) that controls the rotational state of the blower motor (11) according to signals from various sensors. means for calculating a target outlet air temperature (TAO) accordingly;
Means for calculating the blowout air temperature from a signal from a blowout temperature sensor provided at the predetermined outlet; means for determining whether to perform warm-up control based on the target blow-off air temperature (TAO); and means for performing the warm-up control. At the time, the blower air volume to be blown is determined at least according to the blowout temperature detected by the blowout temperature sensor, and in this case, when the blowout temperature is below a predetermined blowout temperature, a predetermined voltage is applied to the blower motor (11) for several seconds. It has a blower motor control means that applies power intermittently in units.

[0005]

[Operation] When performing warm-up control, the present invention
Rather than simply applying a low voltage to the blower motor continuously as in the past to blow out weak wind, we decided to apply a predetermined voltage to the blower motor intermittently every few seconds, preferably 0.5 seconds in 4 seconds. Since the application of a predetermined voltage is repeated continuously for only seconds, there is no need to give cold air to the occupants and make them feel uncomfortable.
) can be virtually grasped. Therefore, the normal warm-up control in which the blowout temperature sensor detects that the heating state of the heater (13) has become sufficient and shifts to the air volume increase state directly detects the heating state of the heater (13). Can be configured without a sensor. In other words, the present invention allows intermittent air blowing in units of several seconds at a predetermined duty ratio (for example, 0.5/4), so that while the sensor functions sufficiently, the air volume is substantially small and does not give a feeling of cold air. It was invented based on a discovery.

[0006]

According to the present invention, there is no need to provide a sensor that directly determines the heating state of the heater, and warm-up control can be performed using a blowout temperature sensor, so that costs can be reduced. Furthermore, since the blower motor is driven intermittently every few seconds, the intermittent applied voltage can be set to a relatively large voltage considering the substantial air volume, making it easy to start the blower motor.

[0007]

[Embodiment] First, an outline of this embodiment will be described. The air blown from the blower motor (11) is passed through at least the evaporator (12), air mix damper (20) and heater (
13) and a servo motor (14) that drives the air mix damper through a predetermined outlet, and a servo motor (14) that controls the rotation of the blower motor and the drive opening of the servo motor according to signals from various sensors. The control unit (7) has the following means.

The target outlet air temperature (TAO) is determined using the inside temperature sensor signal (TR), the outside temperature sensor signal (TAM), the solar radiation sensor signal (TS), and the set temperature signal (TSET) from the temperature setting device (10). When in a predetermined blowout mode, the means for calculating the blowout air temperature (TAO
'); means for periodically determining the deviation (En) between the target outlet air temperature (TAO) and the calculated outlet air temperature; and the deviation (En).
The target opening degree (SW) of the air mix damper (20)
n), means for determining whether or not to perform warm-up control based on the target outlet air temperature (TAO), and when performing the warm-up control, at least the predetermined outlet temperature sensor signal. Means for determining the blower air volume to be blown according to the
Here, when the blowing temperature is below the first predetermined blowing temperature, the blower air volume is set to a predetermined low level (Lo), and when the blowing temperature is below the second predetermined blowing temperature, which is lower than the first predetermined blowing temperature,
A predetermined voltage is intermittently applied to the blower motor (11) to substantially reduce the blower air volume to below the low level (Lo). ] Means for determining the blower air volume based on the target outlet air temperature (TAO) when the warm-up control is not performed.

[0009] When performing warm-up control, in one embodiment, the first blower air volume (V1) to be blown is determined according to a predetermined blowout temperature sensor signal, and the air is blown from the target blowout air temperature (TAO). The final blower air volume is determined as the smaller of the first and second blower air volumes. Examples will be specifically described below.

FIG. 2 shows a schematic diagram of an air conditioner for an automobile using an air outlet temperature sensor. Reference numeral 1 indicates an inside air sensor for measuring the temperature inside the vehicle, 2 an outside air sensor, and 3 a solar radiation sensor. A control unit 7 that receives the signal from the temperature setting device 10
drives the servo motor 14 of the air mix damper (A/M) and controls the A/M damper 20 so that the signals of the blowout temperature sensors 8 and 9 match the target value TAO.

Further, the air conditioner unit is composed of a blower motor 11, an evaporator 12, and a heater 13. Among these, the blower motor 11 is controlled by the control unit 7 via the blower controller 4, and sends out the air inside or outside the vehicle selected by the servo motor 5 for switching between inside and outside air. Reference numeral 6 denotes a damper for switching between inside and outside air, and its opening degree is controlled via a servo motor 5 as shown in FIG. Note that during the warm-up described below, the damper 6 may be considered to be substantially used to introduce outside air.

The air whose temperature has been controlled and dehumidified by the air conditioner unit is switched to the upper outlet duct 15 side or the lower outlet duct 16 side by the outlet mode switching damper 17 driven by the outlet mode servo motor 18, and is distributed into the passenger compartment. be done. In addition, TR is the inside temperature, TAM is the outside temperature, and TS
is the amount of solar radiation, TAH is the outlet temperature on the upper outlet duct 15 side, TAV is the outlet temperature on the lower outlet duct 16 side, S
Wn indicates the opening command signal of the A/M damper.

In the control unit 7 of the automotive air conditioning system shown in FIG. By using the temperature setting gain KSet, inside air temperature gain KR, outside air temperature gain KAM, solar radiation gain KS, and correction constant C that are initialized in advance, the following (1) is obtained.
The target outlet air temperature TAO is calculated according to the formula.

[0014]

[Math. 1] TAO=KSet ・TSET-KR ・TR-K
AM・TAM-KS・TS+C


...(1) On the other hand, for example, when in upper blow mode,
The signal TAV from the upper blowout temperature sensor 8 is taken as the blowout air temperature TAO'. Then, these target outlet air temperatures T
The deviation En is determined from the AO and the blown air temperature TAO', the opening degree SWn of the A/M damper 20 is determined from the PID control equation (2) described later, and the servo motor 14 for the A/M damper is drive-controlled.

Similarly, in the lower blowing mode, the signal TAH from the lower blowing excess sensor 9 is taken as the blowing air temperature TAO', the deviation En is found in the same way, and the PID control formula (2
), the opening degree SWn of the A/M damper 20 is determined, and the servo motor 14 is driven and controlled. In addition, in the top and bottom blowing mode where air is blown from both the top and bottom, the blowing air temperature TAO' is set to (T
AV+TAH)÷2.

The above calculation formula is shown below. (i) Top blow mode: TAO'=TAV
(ii) Bottom blowout mode: TAO′=TAH(
iii) Vertical blow mode: TAO′=(TAV+T
AH)÷2 Deviation En =TAO-TAO'SWn-1; Previous control value SWn; Current control value Kp; Proportional gain, Ti; Integral time, θ; Sampling time T0; Differential time En-2; Previous Deviation, En-1; Previous deviation,
En: current deviation PID control formula Next, as shown in FIG. 3, it is determined (0 or 1) whether to perform warm-up control based on the target outlet air temperature TAO. When performing warm-up control (time 1), the signal TAH from the lower blowout temperature sensor 9 is used instead of the conventional water temperature sensor signal, and the blower air volume to be blown is determined according to FIG.

Here, 0.5/4 in FIG. 4 means that the control unit 7 outputs a signal to the blower controller 4 for 0.5 seconds for a control period of 4 seconds, and the blower motor 11 is weakly driven at a level equivalent to low air volume (Lo). Therefore, as for the blowout air volume, the LO shown in FIG.
There will be a lot of wind, and this will be repeated intermittently. Note that the reason for setting the cycle to 0.5 seconds/4 seconds will be described later.

In other words, the blower motor has an air volume (Lo)
Although a considerably higher voltage than a certain predetermined voltage is applied, the air volume is lower than when this voltage is continuously applied. Generally, the target air temperature TAO during warm-up control is high in the winter season, when the interior of the vehicle is cold. In order to detect the temperature of the heat-exchanged air, the blower motor 14 must be driven to blow air at a predetermined amount or more.

However, since the hot water flowing in the heater 13 is not sufficiently warmed at the initial stage after the engine is driven, the air temperature blown out from the lower air outlet 16 is not heated and is sent into the vehicle interior as cold air. will be done. If this cold air hits the occupants, the feeling will be impaired. Therefore, it is necessary to suppress the amount of air blown out as much as possible.

FIG. 6 shows the tendency of the feeling test results.
Shown below. In FIG. 6, the horizontal axis represents a ratio indicating how many seconds the ON time for applying voltage to the blower motor should be within a 4-second period, and the vertical axis represents the cold air feeling. On the other hand, when the volume of air blown is reduced, the temperature detected by the blowing temperature sensor 16 becomes a lower value than the temperature TW of the hot water actually flowing in the heater 13. In other words, even if the hot water temperature rises, the sensor cannot detect it if the air volume is low. When this happens, hot air does not come out even though the temperature of the hot water in the heater 13 has risen sufficiently. In other words, appropriate warm-up control becomes difficult. Here, when the hot water temperature TW of the heater 13 is kept constant, FIG. 7 shows a change in the temperature detected by the blowout temperature sensor 16 with respect to the blower motor 11 drive (ON) time during a control cycle of 4 seconds. As is clear from FIG. 7, when the air volume is increased, the outlet temperature sensor 16 can detect a value closer to the hot water temperature TW in the heater 13.

In this embodiment, as shown in FIGS. 6 and 7, the blower motor 11 drive (ON) time is set such that the influence of cold air on the occupants is small and the hot water temperature detection ability of the outlet temperature sensor 16 can be maintained to some extent. Select this and set it to 0.
The cycle was set to 5 seconds/4 seconds. FIG. 8 shows a drive circuit diagram of the blower motor 11. The control unit 7 is
In order to control the blower air volume to the determined blower air volume, the blower motor 1
The voltage VM applied to the blower controller 1 is detected from one end of the resistor 40, and the control output voltage BLW from the blower controller 7 is controlled. This voltage BLW is then applied to the thermal fuse 41.
is applied to the base of transistor 42 via. Also, terminal No. in the controller 7. 2 is an EX for driving the blower motor 11 with battery voltage (+B)
-Hi This is a terminal that drives the relay 43, and the terminal No.
．． 1 is a terminal that drives a main relay 44 for supplying power to the blower motor 11 .

A control flowchart according to the above embodiment will be explained below with reference to FIG. The process starts in step 100, and in step 101, signals from the inside air sensor 1, outside air sensor 2, solar radiation sensor 3, temperature setter, and signals from the air outlet temperature sensors 8 and 9 are taken in, and in step 102, the target air outlet temperature TAO is determined. In step 103, it is determined whether or not to perform warm-up control based on the obtained TAO value according to FIG. When the value is 1, that is,
If you want to warm up, proceed to step 104,
According to FIG. 4 and FIG. 10, blower air volume V1, V2
seek. Here, in FIG. 10, the horizontal axis represents the target outlet air temperature T.
AO is taken and the vertical axis is the blower air volume V2. In step 105, the blower air volume V is determined according to equation (3), and the smaller value of the blower air volumes V1 and V2 is taken.

[0023]

[Math. 2] V=min(V1,V2)...(3)
In step 103, when the determination value becomes 0, that is, when no warm-up is necessary, the process advances to step 112, and FIG.
Find the blower air volume V2 according to 0, and calculate this value as V=V2
shall be.

In step 106, the blowout mode is determined according to FIG. 11 based on the target blowout temperature TAO obtained in step 102. Note that FIG. 11 shows TAO on the horizontal axis and four blowing modes on the vertical axis. In step 107, the target A/M damper opening SWn is similarly determined from the above-mentioned equation (2). In step 108, a signal is output from the controller 7 to the blower controller 4 so that the determined blower air volume V is achieved. Steps 109, 110
Then, the controller 7 drives and controls the A/M servo motor 14 and the servo motor 18 for the blowout mode so that the determined target A/M damper opening SWn is set to the blowout mode.

[0025] As described above, during warm-up control, a system using an air outlet temperature sensor without requiring a water temperature sensor can operate in the same manner as conventional air volume control while maintaining a good feeling for the occupants. Become. In the above embodiment, the power transistor 42 is provided in the blower controller 45 shown in FIG. 8 in order to control the air volume intermittently during warm-up.
If the main relay shown in Fig. 8 is turned on intermittently without installing
The same effect can be obtained even if an intermittent air volume is created by turning it off.

Further, in the above embodiment, when the air volume is intermittently operated during warm-up control, the air flow mode is set to the lower air flow mode, and the air volume is controlled by the lower air flow temperature sensor 9. ), and it is also possible to provide a blowout temperature sensor in the defroster blowout passage and perform similar control. In this case, TAH in FIG. 4 increases, and the blower air volume V1 = L
It is also possible to switch to the lower blowing mode when the temperature reaches O (approximately 37° C.).

In FIGS. 4 and 5, a predetermined voltage is applied intermittently in a pulsed manner for 0.5 seconds during a 4-second cycle, but the application time and cycle may vary depending on the vehicle type, blower motor type, etc. It is sufficient to perform the adjustment based on the characteristics shown in FIGS. 6 and 7, and to determine the characteristics as shown in FIGS. That is, in FIG. 6, the cold air feeling suddenly deteriorates at a certain predetermined ratio, and in FIG. 7, the detected temperature also shows a tendency to saturate at a certain predetermined ratio. Therefore, such a predetermined ratio may be determined by a characteristic test, and the cycle may be selected within a range of approximately 2 seconds to 10 seconds, and the intermittent application time may be selected within a range of approximately 0.2 seconds to 1 second.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the present invention.

FIG. 2 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 3 is a characteristic diagram showing the start of warm-up control in the above embodiment.

FIG. 4 is a characteristic diagram showing the relationship between blowout temperature and blower air volume in the above embodiment.

FIG. 5 is a characteristic diagram when the blower motor is driven intermittently in the above embodiment.

FIG. 6 is a characteristic diagram showing the relationship between the intermittent blowing of the blower motor and the cold air feeling in the above embodiment.

FIG. 7 is a characteristic diagram showing the relationship between intermittent blowing and temperature detected by a blowing temperature sensor in the above embodiment.

FIG. 8 is a partial electrical circuit diagram showing a specific connection state between the control unit and the blower motor in the above embodiment.

FIG. 9 is a flowchart showing processing within the control unit in the above embodiment.

FIG. 10 is a characteristic diagram showing the relationship between target blowout air temperature and blower air volume in the above embodiment.

FIG. 11 is a graph showing the relationship between target blowout air temperature and blowout mode in the above embodiment.

FIG. 12 is a graph showing the relationship between the target blowout air temperature and the opening degree of the damper for switching between inside and outside air in the above embodiment.

[Explanation of symbols]

11 Blower motor 12 Evaporator 13 Heater 7 Control unit (1, 2, 3) Various sensors (8,9) Outlet temperature sensor

Claims (3)

[Claims] 1. An air conditioner unit that blows air blown from a blower motor (11) through at least an evaporator (12) and a heater (13) from a predetermined outlet, and according to signals from various sensors. A control unit (7) for controlling the rotational state of the blower motor (11) is provided, and within the control unit (7) there is a means for calculating a target blowing air temperature (TAO) according to signals from the various sensors. , means for calculating the temperature of the blown air from a signal from a temperature sensor provided at the predetermined outlet, means for determining whether or not to perform warm-up control based on the target blown air temperature (TAO), At the time of performing this, the blower air volume to be blown is determined at least according to the blowing temperature detected by the blowing temperature sensor, and in this case, when the blowing temperature is equal to or lower than a predetermined blowing temperature, a predetermined voltage is applied to the blower motor (11). A vehicle air conditioner characterized by comprising a blower motor control means that applies power intermittently in units of several seconds. 2. When the blowing temperature is below the first predetermined blowing temperature, a voltage is continuously applied to the blower motor to set the blower air volume to a predetermined low level, and the blowing temperature is set to the first predetermined blowing temperature. 2. For a vehicle according to claim 1, wherein when the blowing temperature is below a second lower predetermined blowing temperature, a predetermined voltage is intermittently applied to the blower motor in units of several seconds to make the substantial blower air volume below the low level. Air conditioner. 3. The predetermined voltage is intermittently applied to the blower motor at a voltage of substantially 0.2 to 10% during a period of 2 to 10 seconds.
2. The vehicle air conditioner according to claim 1, wherein the application is performed in a pulsed manner for only one second.