JPH0438219A - Air conditioner for car - Google Patents

Abstract

PURPOSE:To improve quick responsiveness of a car room inside blowoff temperature under the condition that clouding of a window glass or a white smoke of car room inside blowoff air is not generated by heightening the upper limit of a target temperature rise speed as a heating amount of a heating unit of evaporator downstream air comes to be larger. CONSTITUTION:An electronic controller 2 for air conditioning controls a heat exchanger 1 so that a car room is to be at a target temperature given by a volume 21. And an electronic controller 4 for a compressor controls a magnet clutch 31 and a control valve coil 32 of the compressor 3 in accordance with an information received from the electronic controller 2 for air conditioning, a detected value of an inlet temperature sensor 28 of an evaporator 12, a detected value of an outlet air temperature sensor 29 and a detected value of a rotation speed sensor 30. In this case, the above controller 2 heightens the upper limit of target temperature rise speed as the heating amount of a heater 16 to heat air in the downstream of the evaporator 12 becomes larger.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a capacity reduction control device for a variable capacity compressor in an air conditioner for an automobile.

[Conventional technology]

As described in Japanese Unexamined Patent Publication No. 1-254418, the conventional device increases the evaporator target suction temperature T' INT (referred to as the target temperature Tea of the downstream air of the evaporator in the examples described later) by 1 degree/second. Then it became.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into consideration the fact that even when the passenger raises the set value of the vehicle interior temperature, the temperature of the outlet air gradually increases due to the additional limit of T' INT (Tea in this embodiment). However, the reaction is slow, making it difficult for passengers to adjust to a comfortable temperature.

An object of the present invention is to provide an air conditioner for an automobile that improves the responsiveness of the temperature of the air blown into the vehicle interior and allows the occupants to easily adjust the temperature to a comfortable temperature under conditions where the window glass is fogged and the air blown into the vehicle interior does not produce white smoke. It is about providing.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an evaporator.

Means for calculating the target temperature of the air downstream of the evaporator, which sets an upper limit on the target temperature and the rate of increase; a variable capacity compressor connected to the evaporator; and a temperature difference between the target temperature and the detected temperature. In the air conditioner for an automobile, which is provided with means for controlling the discharge a volume of the compressor, the calculation means includes a method for increasing the upper limit of the temperature increase rate as the amount of heating by the heating means for the downstream air of the evaporator increases. The means were set up.

[Effect]

In the present invention, the larger the heating amount of the heating means for the air downstream of the evaporator, the higher the duct temperature at the air outlet in the vehicle interior. Even if the temperature rises, it will be cooled by the duct,
It becomes supercooled, becomes white smoke, and does not blow out into the passenger compartment. Furthermore, the larger the heating amount of the heating means, the warmer the window glass becomes, so even if the target temperature rises and the absolute humidity of the air blown into the vehicle interior becomes high, the window glass is less likely to fog.

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 to 10.

FIG. 1 shows a configuration diagram of this embodiment. In other words, it consists of the following five devices. Heat exchange device 1. Air conditioning electronic control device 2 that controls the heat exchange device 1. Compressor for cooling 3. Compressor 3
It consists of a compressor electronic control device 4 for controlling the compressor, an engine control electronic control device 5, and the like.

The heat exchange device 1 and the air conditioning electronic control device 2 are
This is a known device as shown in FIG. 1 of Japanese Patent No. 205504.

An overview of this embodiment will be explained. The heat exchange device 1 consists of the following three units. An intake blower unit 11 consisting of an intake door 8 that controls the intake ratio of inside air 6 or outside air 7 in the vehicle compartment, and a blower 10 driven by a motor 9.
A cooling unit 13 with a built-in evaporator 12 that cools the air, two air mink stores 14 and 15 that control the rate at which the cooled air is reheated, and a heater that uses engine cooling water (temperature, approximately 80°C) 16, and a heater unit 20 incorporating a mode door 19 that controls the ratio of the vent air 17 blowing out to the upper body and the floor air blowing 18 blowing out to the feet.

The air conditioning electronic control device 2 is configured to set a target temperature Ts given by a volume 21 linked to a temperature setting lever provided on the operation panel.
The heat exchange device 1 is controlled so that the interior of the vehicle becomes as follows.

The temperature Tr inside the vehicle is determined by an upper vehicle interior temperature sensor 22 installed on the ceiling and a lower vehicle interior temperature sensor 23 located at the foot of the vehicle.
Furthermore, the detected value Ta of the outside air temperature sensor 24,
And, from the detection value Z of the solar radiation amount sensor 25, the vent blowout 1
7 and the target temperatures Tduo and Tato of the floor air outlet 18 are determined.

The intake door 8 is controlled so that the smaller the temperature difference (Tduo-To) between the vent outlet temperature TdU detected by the vent outlet temperature sensor 26 and its target value TdlIo, the greater the internal air intake ratio.

The motor 9 of the blower 10 operates at a voltage V such that the larger the absolute value ITS-T, l of the temperature difference between Tr and Ts, the greater the air volume.
Increase by 1.

The air mix door 114 has a temperature difference (Tduo-Tdu
) is smaller, the proportion of airflow that bypasses the heater 16 is increased.

The air mix door l115 increases the proportion of airflow that bypasses the heater 16 as the temperature difference (Tdto T,) between the floor blowout temperature Tdffi detected by a floor blowout air speed sensor 27 to be described later and its target value Td1o is smaller.

Mode door 19 is determined by T and Z, vent blowout 1
7 and floor outlet 18 so that the air distribution ratio is
Control is performed using a floor blowout air volume sensor 27 provided at 8.

The wind speed sensor 27 is based on the service bulletin No. 491 (BL-14) issued by Nissan Motor Co., Ltd., issued in October 1988.
The principle is the same as that of the known air flow meter, as described on pages 1-64 to 6-65. In other words, it consists of two thermistor sensors, one of which measures the temperature of the blown air, Tax.
The other is a sensor that generates heat to maintain a constant temperature.

The wind speed G is determined by correcting the current applied to the latter sensor at the temperature Td.

The compressor electronic control device 4 receives information from the air conditioning electronic control device 2, the detected value Tt of the inlet temperature sensor 28 of the evaporator 12, the detected value Te of the outlet air temperature sensor 29, and the engine rotation speed sensor. With the detection value Ne of 30,
Magnetic clutch 31 of compressor 3. and controls the control valve coil 32. The details will be explained with reference to the flows shown in FIGS. 2 to 10.

The engine control device 5 is based on service bulletin No. 578 (YAI-1, YBI-1) published by Nichiwa Jidosha Co., Ltd.
It has the same function as the device described on pages B-62 to B-65 published in June 2016. That is, the air flow meter 33
The basic injection amount (T
p), a correction value Co determined by the detected value of the engine rotation speed sensor 30, etc. is added to determine the fuel injection amount and control the fuel injection time of the injector 34 that supplies fuel to the engine.

Next, the operation of the compressor electronic control device 4 will be explained using a processing flow of a microcomputer that performs calculations and judgments for controlling.

The microcomputer of this embodiment includes a central control unit W (hereinafter referred to as CPU), a read-only memory (hereinafter referred to as ROM) that stores processing procedures (programs, constants),
Random access memory (hereinafter referred to as RA) that stores data
M), input/output terminal (hereinafter referred to as Ilo), analog-digital conversion input terminal (hereinafter referred to as A/D)
, an arbitrary width pulse output terminal (hereinafter referred to as PWM), and a serial communication input/output terminal (hereinafter referred to as SCI). For example, the microcomputer HD6305Z manufactured by Hitachi, Ltd. is used.

A crystal oscillator with an I MHz frequency is connected to the microcomputer, which constitutes an oscillator that determines the basic cycle. The microcomputer program is
The background job (hereinafter referred to as BGJ) shown in FIG. 2 is repeatedly executed.

The execution cycle of this embodiment is approximately 0.1 seconds), and the time interrupt function is used to execute at fixed time intervals (5 milliseconds in this embodiment). It consists of the timer job (hereinafter referred to as TIMER) shown in FIG.

After starting the BGJ in FIG. 2 with the engine switch, in step 100, the BGJ initializes ■/○ and RAM, etc.
Thereafter, the processes from step 101 to step 109 are repeated.

In step 101, between the air conditioning electronic control device 2,
Data communication is performed using SCI. The following information is received from the air conditioning electronic control device 2.

These are the position of the intake door 8, the air distribution ratio Rd of the floor blowout, the voltage v of the motor 9, the outside air temperature Ta, the target temperature Tauo of the vent blowout 17, and the detected temperature T a +□.

In step 102, the detected temperature Tt of the inlet air temperature sensor 28, the detected temperature Te of the t% air temperature sensor 29, and the detected rotational speed Ne of the engine rotational speed sensor 30 are inputted via the A/D.

In step 103, calculations shown in FIG. 4 are performed.

In step 300, the amount of heating by the heater 16, which is located downstream of the evaporator 12 and is a heating means, is captured by the air temperature difference (Tdu-Te) before and after the heater 16.

As shown in the figure, in this example, the lower limit is 2°C, and the value proportional to the air temperature difference (T au - T e ) is the allowable value of Tduo increase per unit time T dt + *
decide.

In other words, the larger the air temperature difference ('rd, -'re) and the larger the amount of heating, the less problems such as white smoke from the air blown into the vehicle interior and fogging of the window glass occur, so that the allowable value Tattm can be increased.

In step 301, for the current control of the control valve coil 32 by TeO, a permissible value for the rise in the target temperature Tea of the evaporator outlet air per unit time is determined according to the characteristics shown in the figure, similar to the limit for the control by Tdu in step 300. Ta
Determine t t m. In this embodiment, step 300
It has the same characteristics as , but depending on the air conditioner system in question,
Characteristics may differ.

In step 302, Ta received in step 101,
Then, from the information on the position of the intake door 8, Teo is determined based on the characteristics shown in the figure. In this example, when Ta<2°C, the characteristics depend on the position of the intake door 8, and when T&≧2°C.
Now, with the characteristics independent of the position of the intake door 8, Te
Decide on a.

Returning to FIG. 2, in step 1.04, it is determined according to the flowchart of FIG. 5 whether to use fixed control on the maximum capacity side for rapid cooling or normal control that is controlled according to the load. In step 400, it is determined whether a flag Fc defined in the RAM indicating that rapid cooling is in progress is set, that is, 1. If true, in step 401, Tau is the target value T++u.

Determine whether it has become colder.

If false, the process proceeds to step 402, where it is determined whether Tauo is lower than the level Tauc that requires rapid cooling control. If it is false, in step 403, the flag Fc
is cleared, that is, set to 0, and the flag Fs indicating the end of rapid cooling control is set to 1.

In that case, the flag Fc is set to 1 in step 404.

If the result in step 400 is false, proceed to step 405;
Determine whether flag Fs is 1, and if false, step 4
The process proceeds to step 02, where it is determined whether or not rapid cooling control is necessary.

Returning to FIG. 2, in step 105, it is determined whether the flag Fc is 1. If true, in step 106, the target energization current of the control valve coil 32 is set. , 0 is set to OA and the maximum capacity side is fixed. On the other hand, in step 107, control shown in FIG. 6 is performed.

In step 500, the possibility of freezing of the evaporator 12 is determined based on the temperature difference (Teo Te), and in step 501, the process branches.

In step 502, the need for cooling is determined by the temperature difference (Tau
o TaU), and if T'du is low temperature, in step 503, Ta control is determined, and in step 504
Then, the flag F indicating Te control is set to O.

In step 501, if the determination is true, step 505
Then, set the flag Fi to 1.

In step 506, it is determined whether the flag Fi is 1, and if it is 1, in step 507 Te control is changed to
In this case, Td control is performed in step 508. Details of each control are shown in FIGS. 7 and 8.

The flow shown in FIG. 7 will be explained. In step 600, it is determined whether the flag Ft was 1 last time. Step 6
At step 01, it is determined whether Tea has risen above the current outlet air target temperature Teot and needs to be restricted in order to prevent white smoke and window fogging due to drain water. If true, in step 602 it is determined whether a flag Fe indicating the time interval for limiting the rise of Tea is 1 or not. The flag Fe is
In the flowchart of FIG. 3, which will be described later, TIMER is set at fixed time intervals to create and compare the unit time of the rise limit.

In step 603, the flag Fe is set to 0, and in step 6
04, it is determined whether the temperature rise (Tea Teai) exceeds the upper limit value "r" determined in step 301 of FIG. 4. In step 605, the temperature rise exceeds the upper limit value T e a t m In step 606, since the temperature rise is below the upper limit Tet+m, Tea is set to a new Teoi.
Let it be x.

If the result in step 601 is false, the temperature is decreasing and the amount of dehumidification in the evaporator 12 is increasing, so it is determined that there is no problem and the flag Fe is set to 0 in step 607.
061\Proceed.

If the result in step 600 is false, Teox has not been determined previously, so the increase in Te is determined by comparing it with the detected temperature Te. At step 608, the flag Fe is set to O.
Then, in step 609, it is determined whether Tea has risen above the current outlet air temperature Te. If true, that is, if the temperature increases, step 604
Similarly, the temperature difference (T e o T e ) is the upper limit T
Determine whether it is higher than e□. In step 611, the temperature rise is limited to the upper limit Teapm, and a new T
Let it be eoi.

As described above, through the processes from step 600 to step 611, the temperature rise of the outlet air target temperature T elf of the evaporator 12 is limited so as not to exceed Tet+m determined in step 301 of FIG. Prevents malfunctions due to temperature rise.

In step 612, it is determined whether a flag F indicating the execution time of the integral process is 1. If true, step 61
3, the flag F1 is set to 0. In step 614, the temperature difference (Teoz Te) is multiplied by a coefficient /T and added to the integral term Ii.

In step 615, it is determined whether the integral term 1 exceeds the upper limit value 11m&X, and if true, in step 616, 1 is changed to I1. &X. In step 617, the integral term (■) and the lower limit value (1. ．． It is determined whether or not the difference is less than , and if true, in step 618, .

Replace with

In step 619, the temperature difference (Teoz Te) is multiplied by a coefficient K, and an integral term 1 is added to determine the energizing current I sat of the control valve coil 32.

Details of Td control will be explained with reference to FIG. Step 7
00, it is determined whether the flag Ft was 1 last time. In step 701, it is determined whether T dUo has risen above the current vent outlet target temperature Tduoz and a restriction is required to prevent white smoke and window fogging due to drain water. If true, in step 702 it is determined whether a flag Fd indicating the time interval for limiting the increase in Tauo is 1 or not. Flag F- indicates the flow of FIG. 3, which will be described later, and TIME.
R is set at fixed time intervals to create a unit time for limit rise.

In step 703, the flag Fd is set to O, and in step 7
At 04, the rising temperature (T duo T duoi) is
Since it is less than the upper limit T 11m determined in step 300 of FIG. 4, T+uo is set as a new T-E OJ.

If step 701 is false, the temperature is decreasing and the amount of dehumidification in the evaporator 12 is increasing, so it is assumed that there is no problem.
At step 707, flag F6 is set to O, and at step 70
Proceed to step 6.

If the result in step 700 is false, Tauoz was not determined last time, so the increase in TdU is determined by the detected temperature T.
Judgment is made by comparing with du. At step 708, the flag F
4 is set to O, and in step 709 it is determined whether Tduo has risen above the current outlet air temperature Tdu. If true, that is, if the temperature increases, the temperature difference (Tduo-Tdu) is the upper limit Td1. ．． Determine if it is higher. In step 711, the temperature rise is limited to the upper limit value T dt r m, which is set as a new Tduoz.

As described above, through the processing from step 700 to step 711, the temperature rise of the blown air temperature Tauoz into the vehicle interior is increased per unit time by Ta5 determined in step 300 of FIG.
ks to prevent problems caused by rapid temperature rises.

In step 712, it is determined whether the flag F, which indicates the execution time of the integral process, is l. If true, step 71
3, the flag F1 is set to 0. In step 714, the temperature difference (TduoiT, +11) is multiplied by the coefficient /T and added to the integral term Ii.

In step 715, it is determined whether the integral term Ii exceeds the upper limit value, □8, and if true, step 716
Then, replace ■fish with Itmax.

In step 717, the integral term is the lower limit I 1llI
Determine whether it is less than n, and if true, step 7
18, replace 1 with I 1m1n.

In step 719, the temperature difference (Tduoz Tdu)
is multiplied by the coefficient K, and the integral term I is added to the control valve coil 3.
Determine the conduction current I sat of No. 2.

Returning to FIG. 2, the process proceeds to step 108. FIG. 9 shows the details.

In step 800, the necessity of idle stabilization processing is determined based on the detected value Ne of the engine speed sensor 30 based on the characteristics shown. If necessary, flag F is set to 1, and the process proceeds to step 802 after the determination in step 801.

In step 802, the heat load of the evaporator 12 is calculated.

It is determined by the product of the inlet air temperature Te and the voltage (1) of the motor 9, and IsatU is determined depending on whether the compressor 3 is turned on or off.

In step 803, it is determined whether I sow determined in step 106 or step 107 is greater than I 5 oil. If true, step 804
Then, turn off the magnetic clutch 31 and proceed to step 80.
5, set Iso□ to the maximum current I 5+) 1 maX.

In step 806, depending on the heat load of the evaporator 12, I
Find somL. In step 807, I sat
It is determined whether or not is greater than or equal to I somL. If true,
In step 808, a flag that allows the magnetic clutch 31 to be turned on is stored in the RAM.

In step 809, I sowυ is set to ISO, and in step 810, it is determined whether it is possible to turn on the magnetic clutch 31 according to I son.

Returning to FIG. 2, the process proceeds to step 109. FIG. 10 shows the details.

In step 900, it is determined whether the determination in step 108 is on or not using a flag stored in the RAM. Step 9
In step 901, the possibility of freezing is determined based on the temperature difference (Teoz Te), and in step 902, the process branches depending on the result.

In step 903, the wind speed GJ to be detected by the wind speed sensor 27 is calculated based on the voltage (1) of the air outlet and the motor 9. In step 904, the presence or absence of freezing is determined based on the wind speed difference (G-GJ), and in step 905, the process branches depending on the result.

In step 906, the magnetic clutch 31 is turned on so that the current in the control valve coil 32 becomes I son.
Controlled by RWM power.

In step 907, the magnetic clutch 31 is turned off, and in step 908, the current of the control valve coil 32 reaches the maximum I.
Control with PWM output so that so mouth □.

Next, the TIMER processing will be explained with reference to FIG. In step 150, the execution period of the integral process (in this embodiment,
500 milliseconds) Counter C installed in RAM
Count up 1. In step 151, it is determined whether the counter Cs has reached a number C1o corresponding to the execution cycle (100=50015 in this embodiment).

If true, the flag F+ is set to 1 and the counter C8 is returned to O in step 152.

In step 153, a counter Ca for counting the execution period of the temperature rise limiting process of T++uoi in steps 700 to 711 in FIG. 8, that is, the unit time of temperature rise limiting, is counted up. Step 154
Then, it is determined whether the counter Cd has reached the number Cao corresponding to the execution cycle.

If true, in step 155, the flag Fa indicating the passage of unit time is set to 1, and the counter C6 is returned to O.

In step 156, a counter Ce that counts the execution cycle of Teoi's temperature rise limiting process in steps 600 to 611 in FIG. 7, that is, the unit time of temperature rise limiting, is counted up. In step 157, it is determined whether the counter Ce has reached a number Ceo corresponding to the execution cycle.

If true, in step 158 the flag Fe is set to 1,
Return the counter Ce to O.

When the above processing is completed, the process returns to the flow shown in FIG. 2 and restarts the process from the next step where the timer interrupt occurred.

According to this embodiment, the amount of heating is determined by the difference in air temperature between the front and rear of the heater 16, which is a heating means, and the amount of heating is determined by the temperature difference between the
Determine the allowable temperature rise value Te□1 or T d* + m for Te or Tdu, which is the downstream air temperature in step 2, and
It limits the temperature rise and prevents white smoke and fogging of the window glass due to drain water, so it can be used under conditions where the amount of heating is large, the temperature of the duct inside the car outlet and the window glass is high, and no problems will occur due to the temperature rise. , the temperature rises faster, responsiveness improves, and it becomes easier for the occupants to set the temperature.

Further, the temperature of the evaporator 12 is controlled by changing the capacity of the compressor 3 and the current flowing through the control valve coil 32. T
e and T. Limiting the temperature rise is equivalent to limiting the rate of capacity reduction of the compressor 3, and step 6 in FIG.
00 step 611 and step 70 in FIG.
Step 711 serves as a means to limit the speed at which the capacity of the compressor 3 decreases.

Furthermore, the horizontal axis of the characteristics of step 300 and step 301 in FIG. 4 is the temperature difference (T d
uT e ), which captures the amount of heating. However, the air mix door may be opened at an opening angle of 14° to 15°. That is, the opening degree of the air mix doors 14 and 15 determines the ratio of air passing through the heater 16 to air bypassing the heater 16, and the amount of heating is determined by that ratio.

〔Effect of the invention〕

According to the present invention, the amount of heating downstream of the evaporator 12 is large, the temperature of the duct and window glass of the air outlet in the vehicle interior is high, and white smoke of drain water and fogging of the window glass occur as the temperature of the evaporator 12 increases. Under conditions where this is unlikely to occur, the allowable upper limit temperature of the evaporator temperature will be set earlier, and the occupant will be able to respond more quickly when changing the temperature setting, making it easier to adjust to a comfortable temperature.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention and a flowchart of the second ram. 3... Compressor, 4... Electronic control device for compressor control,
DESCRIPTION OF SYMBOLS 12... Evaporator, 16... Heater, 26... Vent blow-off temperature sensor, 29... Evaporator outlet air temperature sensor, 32... Control valve coil. No. 2 $3 v40 No. 1

Claims (1)

[Claims] 1. The evaporator has an upper limit on the rate of increase in target temperature.
Means for calculating the target temperature of the air downstream of the evaporator, means for detecting the temperature of the air downstream of the evaporator, a variable capacity compressor connected to the evaporator, and a temperature difference between the target temperature and the detected temperature, In the automotive air conditioner including means for controlling the discharge capacity of the compressor, the calculation means includes means for increasing the upper limit of the temperature increase rate as the amount of heating by the heating means for the downstream air of the evaporator increases. An air conditioner for an automobile characterized by being provided with.