JPS5896952A - Method of controlling air conditioner for automobile - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the capacity of an automotive air conditioner.

The refrigeration cycle of a conventionally well-known automobile air conditioner is:

As shown in FIG. 1, compressor Ill and condenser 8. Receiver 8
．． Ill valve4. It consists of an evaporator 6.

Compression Il! ] is driven by an automobile engine (not shown) via an electromagnetic clutch 7, so as the engine speed increases, the compressor speed increases.

Therefore, when the rotational speed of the compressor 1 increases or the cooling load decreases due to a drop in outside temperature, etc., the fin temperature of the evaporator 5, that is, the evaporation temperature of the refrigerant, decreases to below 0°C. If the fins are frosted or frozen, the amount of air blown by the blower 8 decreases, and the cooling capacity decreases. Sonota, in order to prevent this frosting phenomenon and to control the temperature inside the vehicle, the air temperature immediately after the evaporator 5 is detected by a temperature sensor H6 such as a thermistor.

The evaporation temperature of the refrigerant is controlled by opening and closing the contact log of the relay 10 in the control circuit 9C shown in FIG. At the same time, the air temperature immediately after the evaporator is controlled.

By the way, in such a configuration, if the cooling load decreases or the rotational speed of the compressor 1 increases.

As the compression function becomes excessive and the capacity of the refrigeration cycle exceeds the cooling load, the I
The temperature of the air directly in the evaporator decreases.

At point 0, the temperature is below the set temperature To. Although it's funny.

Due to its heat capacity, the temperature sensor 6 has a time delay as shown in IP- in case 8 before the control circuit 9 is activated, and the temperature sensor 6 has a time delay as shown in IP- in case 8, and the temperature sensor 6 has a time delay (i.e., At time I), the air temperature T further decreases and becomes considerably lower than the set temperature To. Then, the control circuit 9 operates at point 8, and when the kuwochi 7 is cut off, the compression 4111 is stopped, the expansion ff4 is closed, and the supply of liquid refrigerant to the evaporator 5 is stopped. Then.

The internal pressure Pl of the evaporator 185 increases and the superheat of the refrigerant increases, so the effective heat transfer area of the evaporator 5 decreases.

As a result, the air temperature T immediately after evaporation 885 rises rapidly, reaching the set temperature To or higher at six points. However, for the same reason as above, there is a time delay (summer time) in the temperature sensor 60, so the air temperature T continues to rise until the time a when the control circuit 9 is activated. At point 5, the control circuit 9 is activated, the clutch 7 is reconnected, the compression III starts moving, and the above operation is repeated thereafter.

However, in the conventional type, regardless of the fluctuations in the cooling load due to changes in the outside temperature, etc., Compression III is always at its maximum capacity and operation is interrupted due to haze, so the drive load of the drive source of Compressor I is always at its maximum capacity. As a result, as power consumption increases,
iI sound also gets louder.

Further, since the rotation speed of the compressor 1 is proportional to the engine rotation speed, the cooling capacity depends on the engine rotation speed.

Konotame, the cooling capacity is insufficient when the engine is operating at low speed,
There is a problem in which the cooling capacity becomes excessive during high-speed operation.

The present invention has been made in view of the above points, and uses a variable capacity type compressor that has a built-in capacity variable member that changes the discharge capacity in stages, and uses a variable capacity compressor that changes the static temperature immediately after the evaporator or It senses the temperature or refrigerant pressure related to the degree of cooling of the evaporator, such as internal refrigerant temperature and refrigerant pressure, and also senses the ambient temperature of the vehicle.

In response to these rain detection signals, the discharge capacity of the compressor is controlled in stages, and the operation of the compressor is controlled to be stopped.

It is an object of the present invention to provide a method for controlling an air conditioner for an automobile, which allows a refrigeration cycle to operate at a capacity corresponding to the load at the time, and which can reduce the power consumption and noise of a pressurized compressor.

Further, the second invention detects the rotational speed of the on-vehicle engine directly connected to the compressor, the ambient temperature of the vehicle or the evaporator intake air temperature, and detects the air temperature e after the evaporator IT in the first invention.
, is the cooling degree of the evaporator such as the refrigerant temperature in the evaporator and the refrigerant pressure #C together with the sensing signal of the related temperature or refrigerant pressure,
Depending on these signals.

It performs stepwise control of the discharge capacity at a pressure of 1its and controls the operation stoppage to prevent the cooling capacity from becoming excessive when the engine is running at high speed, or from being insufficient when the engine is running at low speed. Suppresses fluctuations in cold 7JJ capacity that depend on engine speed.

It is an object of the present invention to provide a method for controlling an air conditioner for an automobile, which operates with a cooling capacity corresponding to the cooling load at that time and exhibits the same effects as the first invention.

Embodiments of the first invention shown in the drawings will be described below.

The refrigeration cycle in the method of the present invention may be the same as that shown in FIG. 1, so its explanation will be omitted. Figure 4 (a) schematically shows the entire control system of the method of the present invention. 11 is a resin ventilation casing of an automobile air conditioner, and inside it is @
An evaporator 5 and a motor-driven blower 8 shown in FIG. 1 are provided. The left end side of the ventilation casing 11 is connected to an inside air intake port and an outside air intake port via an outside/outside air switching box (not shown), and the right end side is connected to an air outlet (an upper cooling air outlet) into the vehicle interior via a heater unit (not shown). (lower air outlet for heating, etc.) is connected to V. A compressor 12 is connected to the refrigerant circuit on the outlet side of the evaporator 5.

This compressor 12 is driven by an automobile engine via an electromagnetic clutch 18. Furthermore, this pressure IIA machine 12 is configured as a variable capacity type having a built-in capacity variable member 18 for varying the discharge capacity, as will be described later. 14 is a temperature sensor consisting of a thermistor for sensing the air temperature immediately after the evaporator, and 19 is a thermistor for sensing the representative temperature around the vehicle, for example, the temperature of the cooling air in front of the condenser 8. temperature sensor 16, both temperature sensors 14.1
9 is a control circuit that receives a signal as input; 16 is the compressor 1B;
This is an electromagnetic valve for driving the variable capacity member 18 inside, and is controlled by the output of the control circuit 16.

Reference numeral 21 indicates an operation switch for the air conditioner, a 2g air conditioner switch, and 28 indicates an on-vehicle power supply.

11!4 (b), ta+ is an example of the mounting position of a temperature sensor 51819 consisting of a thermistor for sensing the ambient temperature of the vehicle. 60 is an in-vehicle engine, 61 is an in-vehicle air conditioning unit, and 68 is a fender mirror.

FIG. 5 shows a specific example of the control circuit 16. The output 31m is determined by the potential V determined by the control circuit 16 and the reference potential V determined by the resistance value of the resistor 8L84. 85 is a relay controlled by this comparator output 31m,
The electromagnetic clutch 13 is energized intermittently.

A comparator 86 has a potential v determined by the resistance value of the resistor 87 and the thermistor resistance value R1φ of the temperature sensor 19.
The output Sem is determined by J and the reference potential (2), 4 determined by the resistance value of the resistor 88.89. 40 is a relay controlled by this comparator output 86aK, which turns the electromagnetic valve 16 on and off.

Both temperature sensors 14 and 19 are negative characteristic thermistors whose resistance value decreases as the temperature rises, and the change in the t-i star resistance value R, 4, R1, and the comparator output 31 m
, 36m are set as shown in FIG. 6 (al, (b)).

Comparator output 81m as shown in Figure 6 (a) Ic
For example, if the temperature of the blowing air immediately after the evaporator rises above 4℃ and RI4 decreases from R14A, the temperature of the blowing air immediately after the evaporator becomes zH4z, and conversely, if the temperature of the blowing air immediately after the evaporator falls below, for example, 8℃, the RI decreases.
When 4 increases more than R,,B, it becomes 1'/L o '' level.

@Figure 6 (b) <As shown, the comparator output 36m becomes zH+〃 level when the ambient temperature of the vehicle rises from the set temperature, for example 26℃ and R1 decreases from RH A, and conversely, when the ambient temperature of the vehicle increases When the set temperature drops below, for example, 24° C. and Ru increases more than R1@, it reaches the zL6p level.

Next, an example of a specific configuration of the compressor 12 will be described.

@ In Figure 7, 100 is a cylindrical rotor, and 101 is a vane slidably inserted in the radial direction into a slit 102 provided in the rotor 100Ic.

Although only two sheets are shown in FIG. 9, there are actually four sheets arranged at equal intervals. 108 is a cylindrical V II cylinder that restricts the reciprocating movement of the vane 101 in the radial direction;
, 105 are a front side plate and a rear side plate that sandwich both ends of the cylinder 103 through a small gap with the rotor 100 and vane 101. These rotor 100° vanes 101. Cylinder 108 and front side plate 104. Rear side plate 10
5 forms a working space V. Also, cylinder 108°7
0nt side delay) 10'4. The rear side plate 105 is attached to the bolt 1 along with the housing 106 and 107.
The tightening is fixed at 08. Note that the rotor 100 is the rotating shaft 1
09, and the one-rotation shaft 109 is the bearing 1.
10 by the front side plate 104. It is rotatably supported by a rear side plate 105 and receives driving force from an automobile engine via an electromagnetic clutch 18 and the like.

111 is a shaft sealing device that maintains a seal with the outside air.

And front side derate 104 and housing 1
Inhalation chamber 112 by 06! is formed.

The refrigerant sucked into this suction chamber 112 from the evaporator 6 of the refrigeration cycle is sucked into the working space V through a suction port 118 (FIG. 9) opened in the front side relay 104. That is, the zero working space V is filled with refrigerant at suction pressure (as shown in FIG. 9, ta). Then, the refrigerant sucked into the working space V is compressed as the volume of the working space V decreases, and in the most compressed state is discharged from the discharge port 114 of the cylinder 103 through a discharge valve (not shown) etc. to the housing. 10? It is discharged to the discharge M1107 m inside.

It is then discharged to the condenser 2 of the freezing tube.

P is an unloading port according to the present invention, which opens in the front side plate 104 and communicates the working space V with the suction chamber 11g. Therefore, when the unloading boat P is open, the refrigerant is not compressed until the working space V is separated from the communication with the unloading boat P. Road boat P
The space volume vl at the start of compression in the open state of
The space volume v11 at the start of compression with the unloading boat P closed is shown in Figure 9(a).
tC is shown. In exceptional cases, the unloading boat P is opened at a position where vl is about 80% to 60% of V.

116 is an on-off valve that opens and closes the unloading boat P. To specifically explain the structure of this on-off valve 115, the eighth
As shown in the figure, there is a valve body 115m that is attached and detached from the bow) P, a spring 115b that biases this valve body 115m in the opening direction with a predetermined load, and a bellows 7 ram 115 that drives the valve body 115m, which also serves as a spring seat. Plate 1 for guiding Perofram 115e
16f. The valve body 115m is made of a material with high folds such as stainless steel. A pilot pressure introduction passage 117 communicates with the chamber 116d on the back side of the perofram 1156, and pilot pressure, that is, suction pressure or discharge pressure, is applied by controlling the electromagnetic valve 16.

Is 117a a pyro? ) A restriction formed in the pressure introduction passage 117 prevents pyropressure pressure from being suddenly applied to the chamber 115d. On the other hand, Perofurafu 1156
The pressure of the suction chamber ltg is applied to the chamber 115 on the surface side.

The variable capacity member 18 is constituted by the combination of the above-mentioned port P and the on-off valve 1115.

The driving of the on-off valve 115 of the port P is controlled by the solenoid valve 16.

As shown in FIG. 10, the upper rudder solenoid 5'P16 has eight pressure ports, namely a suction pressure introduction port 16m and a discharge pressure introduction port 16b.
and a pilot pressure outlet 16a, the suction pressure inlet 16m introduces the pressure of the suction chamber 11g, and the discharge pressure inlet 16b introduces the pressure of the discharge chamber 107a. Exit 16c
is the chamber on the valve body closing side of the on-off valve 115, that is, the pilot chamber 11
It leads to 5d. The position of the valve body 16s made of a magnetic material is controlled by turning on and off the energization to the coil 16d, and suction pressure or discharge pressure is selectively applied to the viroft pressure outlet 16sIC of the solenoid valve 16. ing.

Therefore, when the pilot pressure outlet 16aK suction pressure is introduced, the pyroma chamber 115d becomes suction pressure.
Therefore, the valve body 115m moves in the opening direction by the setting force of the spring 115b, and the on-off valve 115 opens the port (P). vice versa,
When the discharge pressure is introduced into the pilot pressure outlet lee, the pilot chamber 115d similarly becomes the discharge pressure, so the valve body 115m moves in the closing direction against the setting force of the spring 115b; opening/closing 51?116 blocks boat P.

In addition, the solenoid valve 16 is over III! In order to prevent malfunctions caused by this, the compressor 12 is disposed in contact with a relatively low-temperature portion 1 of the compressor 12, such as a service pulp (not shown) through which the suction refrigerant passes, and the front housing 106.

Next, the operation of the control method of the present invention will be explained. If the ambient temperature of the vehicle is higher than 26°C and the thermistor resistance value R1s of the temperature sensor 19 is smaller than R7°, the comparator output 86a becomes the 1H1J level, and the relay 40 normally closed contacts 40m are opened.

The solenoid valve 16 is not energized. Therefore, the solenoid valve 16 is
The valve body 16 is as shown in Figure 0, and the valve body 16 is connected to the discharge pressure inlet 1.
6b is open, the valve body 116a of the on-off valve 116
is pressed by the discharge pressure and closes the boat-P. As a result, the discharge capacity of the compressor 12 is increased to a large capacity (1
00% capacity) lc is set.

In the above condition, if the evaporator discharge air temperature is higher than 4°C, the thermistor resistance value R of the temperature sensor 14 is Rl 4
becomes smaller than A, and the comparator output 81m becomes z)
Since the level is l i /l, the normally open contact 85m of the relay 86 is closed and the electromagnetic clutch 18 is connected. Therefore, the compressor 12 operates at full capacity with a large discharge capacity.

When the evaporator outlet air temperature drops below 8°C, R
34 becomes larger than R,,B, and the comparator output 31
Since a reaches the "L" level, the normally open contact 815m of the relay 85 is opened, the electromagnetic clutch 18 is disconnected, and the operation of the compressor 1g is stopped.

This prevents 70 strokes of the evaporator 6.

Next, the ambient temperature of the vehicle becomes lower than 24°C.

When the thermistor resistance value RII of the temperature sensor 19 becomes larger than RBB, the comparator output 86a becomes z l, 6
level, and the normally closed contact 40 of the relay 40 becomes closed, so the solenoid valve 16 is energized. Therefore, the valve body 16 of the solenoid valve 16 is attracted by the coil p16dK, and closes the discharge pressure inlet 11b and opens the suction pressure inlet 16m.
15m is pressed by the spring 115b to open the port P.

Thereby, the discharge capacity of the compressor 12 is set to a small capacity.

In the above state, if the evaporator outlet air temperature is higher than 4°C, the thermistor resistance value Rxh"Rra of the temperature sensor 14
*It becomes smaller and the comparator output is 81 HLz
level, the normally open contact 85m of the V-85 closes and the electromagnetic clutch 18 is connected. Therefore, the compression
1g is operated with a discharge capacity of Honkyosha or a small capacity.

When the evaporator outlet air temperature drops below 8°C, R
04 becomes larger than RI 4 B, and the comparator output 81a becomes zLolRep. Therefore, the normally open contact 85m of the relay 86 becomes open, the electromagnetic clutch 18 is disconnected, and the operation of the compressor 12 is stopped.

This prevents the evaporator 5 from frosting.

As described above, in this embodiment, when the ambient temperature of the vehicle is high and cooling capacity is required, the compressor 12 is alternately switched between high-capacity operation and operation stop to control the evaporator 6 to prevent frosting. On the other hand, when the ambient temperature of the vehicle is low and the cooling capacity is not so necessary, the compressor 612 is alternately switched between small capacity operation and operation stop to control the evaporator 6 to prevent frosting. Note that it is also possible to replace the switching from high-capacity operation to operation stop when the ambient temperature of the vehicle is high with switching from high-capacity operation to small-capacity operation.

FIG. 11 shows another embodiment, in which a comparator 41 is added whose input signal is a potential V determined by the thermistor resistance value R84 of the sensor 14.

The output 411 of the comparator 41 turns on and off the relay 42 and controls the operation of the solenoid valve 16. Base of comparator 41 Ik t position V @ + @ : 27 /
< y-lower than the reference potential of 81 (Vi<Vi
) Since it is a membrane chamber, the output 81m and 41m of the single comparator 81.41 is the thermistor resistance value R of the temperature sensor 14.
14 as shown in FIG.

On the other hand, the total force of Compan-Yu 86 was 86 m, as mentioned above.
This is the same as the characteristic shown in Figure 6(b), and this output 36
The transistor 48 is turned on and off by m, thereby controlling the operation of the relay 4g.

Next, the operation of this embodiment will be explained. The ambient temperature of the vehicle is now higher than 26°C, and the resistance value R1 of the temperature sensor 19 is R.
If it is smaller than 8.A, the output of comparator 86 is 861A.
becomes the HLN level, and the transistor 48 is turned off. At this time, if the evaporator outlet air temperature is higher than 6℃, 2
The outputs 81m and 41m of the two fan parators 81°41 are both at /H1I level ~, the relay 35 is energized and its normally open contact 85m is closed, and the electromagnetic club 4-18 is connected, so the compression is 1112! is activated. At the same time, the relay 42 is also energized and its normally closed contact 4B& is opened, so that the solenoid valve 16Ic is not energized and the compressor 12 operates at full capacity at a large capacity (100% capacity). Next, when the evaporator outlet air temperature gradually decreases to below 6°C and the value of +R,, becomes higher than RI4D,
Comparator output 41 is 1Loj, relay 4
2 is turned on, and the solenoid valve 16 operates.

The compressor discharge capacity is a small capacity (80% to 60%) K-.

Here, if the evaporator outlet air temperature becomes lower than 3℃
When the value of +R14 becomes higher than RI43, the comparator output 81a becomes 1LoI, the relay 86 is turned off, and the electromagnetic clutch 13 is disengaged, so that the operation of the compressor 12 is stopped.

As a result, the temperature of the evaporator blowing air gradually increases, and the above operation is performed in reverse, and the switching between operation stop ← → small capacity operation and large capacity operation is repeated.

On the other hand, the ambient temperature of the vehicle becomes lower than 84°C.

When RB becomes larger than R1@B, comparator output 8
6 becomes NLol and the transistor 48 turns on, so the comparator output 41m becomes 1' L o /
/, so the relay 42 is turned on and the solenoid valve 1 is turned on.
6 is activated, and the capacity of the compressor 11 becomes small. This small capacity operation is then interrupted by the comparator output 81m. In other words, when the ambient temperature of the vehicle is low, switching from stop to low-capacity operation is repeated.

Next, an embodiment of the eighth invention shown in the drawings will be described. The refrigeration cycle in the method of the present invention is the same as in the 1g1 invention. FIG. 18 schematically shows the entire control system of the method of the present invention.

In the embodiment of the present invention, a rotation speed sensor 61'' detects the rotation speed of an on-vehicle engine 60 that is directly connected to the compressor 12 and drives the compressor 12.
’c ! 62 converts it into a voltage signal, obtains a voltage corresponding to one rotation speed, and inputs it to the control circuit 15.
A signal according to the outside temperature detected by the temperature sensor 19, the evaporator 5
These signals are input to the control circuit 15 along with the signals detected by the temperature sensor 14 for sensing the air immediately after the air flow, and these signals control the solenoid valve 16 to change the refrigeration capacity of the compressor 12 in stages. At the same time, the electromagnetic crane v+18 is controlled to stop the operation of the compressor 12.

The rest of the configuration is the same as the embodiment of the first invention shown in FIG. 4(a) Ic, so the explanation will be omitted.

FIG. 14 shows an example of the control circuit 15 of the present invention. For the embodiment of the first invention shown in FIG. 5, a rotation speed sensor 61. A frequency-voltage converter 62. thereby converting the sensed frequency sensing signal into a voltage. The difference is that a comparator 66 and a transistor 66 are added to input the signal. The comparator 65 has a signal voltage V corresponding to the engine rotation speed.
, and the reference potential v1 determined by the resistance value of the resistor 68.69 is input, and the output 65m of the comparator 66 is determined by the value of l V7 and vl.

And, by this output 65 island, transistor 66°67
is turned on and off to intermittently energize the relay 40 and control the operation of the solenoid valve 16.

As an example, the rotation speed sensor 61 receives an intermittent signal 1 of the ignition coil.
A generator, a photoelectric diagonal meter, etc. can be used.

The operation of the comparators 81 and 86 is the same as in the first invention, and the relationship between the change in the thermistor resistance value R141RII and the comparator output 81m+86m is shown in FIG.
(b) Ic is set as shown.

The input/output characteristics of the frequency-voltage converter are set as shown in FIG. 16 (61), and the relationship between the change in engine speed and the comparator output 65m is set as shown in FIG. 15 (dl).

As shown in FIG. 15(e), when the engine speed increases from, for example, 1200 rpm, the comparator input signal V
, becomes lower than the reference potential Va, the comparator output 6
5m is at the H+ level as shown in Figure 15 (dl), and conversely, the engine speed is, for example, 11000 rpm.
The comparator input signal v1 becomes lower than the reference potential Vm.
From 44, the output 65 is +'
It becomes L o ” level.

Next, the operation of the control method of the present invention will be explained.

The ambient temperature of the vehicle is now higher than 26℃, and the temperature sensor 19
When the thermistor resistance tI Rt is smaller than R,・mu, the comparator output 86a becomes the IHifi level, turning on the TofunS)\Taro7 and energizing the sari relay 40.
The normally closed contact 40m of the relay 40 is opened, and the solenoid valve 16 is not energized. Therefore, the discharge capacity of compressor 1B is large (
1004 capacity). At this time, if the engine speed is less than 1100 Orp, the comparator 6
Since the output 66a of the transistor 5 is at the 1LoN level and turns off the transistor 66, the control of the solenoid valve 16 is not affected. That is, the discharge capacity of the compressor 12 is set to a large capacity.

Conversely, when the engine speed increases by 1200 rpmJ:'), the output 65m of the comparator 66 becomes zH+!
level, the transistor 66 turns on and the output 36 & of the comparator 86 is forced Ic # L 6 l
Becomes Rubel. Therefore, the transistor 67 is turned off, the operating current of the relay 40 is interrupted, the normally closed contact 401 is closed, the solenoid valve 161C is energized, and the compressor 12 is set to a small capacity (80% to 60%).

On the other hand, the shoulder temperature of the vehicle is lower than g+℃, and temperature sensor 1
When the thermistor resistance 1[R1· of 9 is larger than R1·A, the comparator output 86a becomes eLoa level,
The transistor 67 is turned off, the operating current of the relay 40 is cut off, the normally closed contact 40a is closed, the solenoid valve 16 is energized, and the discharge capacity of the compressor 12 is set to a small capacity.

At this time, the engine speed, that is, the level of the comparator output 65m, and therefore the transistor 66 is turned on.
Off status I! ! However, since the conhalator output 86m is always at the #L@' level, the discharge capacity of the compressor 12 is set to a small capacity regardless of the engine speed.

As described above, the discharge capacity of the compressor 12 is set to a large capacity only when the ambient temperature of the vehicle is higher than 26° C. and the engine speed is lower than 1100 Orp, and the discharge capacity of the compressor 12 is set to a large capacity. is other than the above conditions, the discharge capacity of the compressor 12 is set to a small capacity.

When the air temperature immediately after the evaporator is higher than 4°C, the comparator output 81i is /Hi'? level, the normally open contact 85m of the relay 85 becomes closed, the electromagnetic clutch 18 is connected, and the compressor 1g enters the operating state at the above-mentioned set capacity. on the other hand.

When the air temperature immediately after the evaporator drops below 8℃, the comparator output 81m becomes /L6z level, and relay 8
5's normally open contact 86m is open! l, electromagnetic clutch 1
8 is cut and the operation of the compressor 12 is stopped. This results in
Frosting of the evaporator 5 is prevented.

As described above (0) In this embodiment, when the ambient temperature of the vehicle is high, the cooling load is large, and the engine speed is low (the compression capacity of compression 1II12 is small).

The evaporator 6 is controlled to prevent 70 strokes by alternately switching between high-capacity operation and shutdown of the evaporator 6, and also compensates for the lack of cooling capacity and operates with an appropriate cooling capacity according to the cooling load. On the other hand, when the ambient temperature of the vehicle is low and the cooling load is small, or when the engine speed is high and the compression capacity is large, the compressor 12 is alternately switched between small capacity operation and operation stop to prevent the evaporator 5 from frosting. control, suppress excessive cooling capacity, and operate with an appropriate cooling capacity according to the cooling load.

Note that it is also possible to replace the switching between high-capacity operation and operation stop when the ambient temperature of the vehicle is high and the engine speed is low with switching between high-capacity operation and small-capacity operation.

FIG. 16 shows another embodiment, in which an engine 600 rotation speed sensor 61. A frequency voltage converter 6g that converts the frequency sensing signal into a DC voltage, and a comparator 65 that inputs the signal. The difference is that Tofun S/Nug 66 is added.

What is the function and purpose of comparator 41.31.36?

It is the same as that of the first invention, and the characteristics are shown in FIG. 17 (&).

(b) 1 is set as shown.

Further, the function and purpose of the comparator 66 are the same as in the above embodiment of the second invention, and the characteristics are shown in FIG. 17 (Cl
C The settings are as shown.

Next, the operation of the ninth embodiment will be explained.

The ambient temperature of the vehicle is now higher than 26℃, and the temperature sensor 19
When the resistance MR,- is smaller than R1sm, the output 36m of the comparator 86 becomes #Hi4' level ~, and the power supply p4+3 is turned off. At this time, if the engine speed is lower than looorpm, the output 65m of the comparator 66 becomes the zLo level, and the 1st rotor 6 is turned off.

In this case, the first
The same operating mechanism as in the embodiment described in FIG. 2 is performed.

That is, if the evaporator outlet air temperature is higher than 6°C, the compression Ia1g
performs full operation at large capacity (100% capacity).

When the evaporator outlet air temperature gradually decreases to below 5°C and above 8°C, the compressor discharge capacity decreases to a small capacity (
80% to 50%), and the compressor 18 operates in this state.

Further, when the temperature of the air blown from the evaporator falls below 8° C., the operation of the compressor is stopped by the action of the comparator 81. Conversely, when the evaporator outlet air temperature rises, the above operation is performed in reverse, thereby repeating the switching from high capacity operation to small capacity operation to operation stop.

Further, when the engine speed is higher than 120 rpm, the output 66m of the comparator 66 becomes the #H4N level, and the transistor 66 is turned on. Therefore, the output 41m of the comparator 41 is forced to the zLoN level, the operating current of the relay 42 is interrupted, and its normally closed contact 42m is closed. When lIc, the solenoid valve 16 is energized and the discharge capacity of the compression 111g is set to a small capacity. In this case, if the evaporator outlet air temperature is higher than 4℃, the comparator output 31m is z
When the Hl k level is reached and the electromagnetic clutch 18 is connected, the compressor operates in a small capacity state, and when the reverse IC evaporator outlet air temperature is lower than 8°C, the comparator output 811 becomes #LoN.
level, the electromagnetic Kuramachi 18 is cut off and the compressor stops.

On the other hand, when the ambient temperature of the vehicle becomes lower than 24°C and +R1e becomes larger than R1@B, the comparator output 86m goes to Lo# level and the transistor 48 turns on, so the comparator output 41m is forced to lLo.
Becomes Rubel. Therefore, the pressure lllll11g is set to a small capacity a. Is this Togi 411 forced? Since it is a LoN level, the level of 66a does not contribute to the selection of the discharge capacity of the compressor 1B, that is, the discharge capacity of the compressor 12 is set to a small capacity regardless of the engine speed, and the evaporation The compressor 41111 is operated intermittently depending on the level of the output 811A of the comparator 81 which senses the temperature of the air blown out from the compressor and operates based on the signal.

As mentioned above, when the ambient temperature of the vehicle is higher than 26°C and the engine speed is lower than 11000 rpm,
The compressor is controlled to be switched between high-capacity operation, low-capacity operation, and operation stop depending on the temperature of the air blown from the evaporator. On the other hand, when the ambient temperature of the vehicle falls below 24°C or when the engine speed rises above 120 rpm, the compressor operates at a small capacity or stops operating depending on the temperature of the evaporator air discharged. will be controlled by switching.

In the above-mentioned embodiments according to the first and second inventions, the air temperature immediately after the evaporator is sensed and controlled, but the refrigerant pressure inside the evaporator, the refrigerant temperature, or the evaporator fin relative The surface temperature of the refrigerant pipe, etc. may be sensed, and this may be used as the control signal 2 for capacity control.

In addition, if the resistor 87 etc. is made into a variable resistor that can be manually adjusted from the outside so that the user can freely adjust the set ambient temperature of the vehicle, the purpose of controlling the room temperature in addition to preventing frosting of the evaporator 6 can be The present invention can also be applied to

The present invention can also be carried out in the same manner even if the temperature sensor 19 is installed in the air suction part of the ventilation casing 11 (the left end in FIG. 4) to sense the suction air temperature instead of the ambient temperature of the vehicle. can.

Further, the compressor 12 is not limited to the vane type, but other types such as a swash plate type can also be used.

As described above, according to the present invention, in addition to sensing the air temperature immediately after the evaporator, the ambient temperature or intake air temperature of the vehicle is also sensed, or the engine rotation speed is also sensed, and these sensing signals are used. Since the compressor capacity is controlled in stages according to the load and the stoppage of the compressor is controlled, the refrigeration cycle can be operated at the optimal capacity according to the load or engine speed at that time. This has the great effect of significantly reducing the power consumption and noise of the compressor. In the special IC of the present invention, the shoulder temperature or intake air temperature of the vehicle is sensed, and when these sensed temperatures are low, the compressor capacity is reduced to prevent excessive cooling and realize power saving effectively.

Furthermore, if the engine speed is detected, the compressor capacity is reduced during high-speed driving to prevent cooling capacity from becoming excessive, and conversely, when the ambient temperature of the vehicle is high during low-speed driving, the compressor capacity is reduced. By increasing the machine capacity - preventing insufficient cooling capacity, it is possible to effectively save power.

[Brief explanation of the drawing]

Fig. 1 is a refrigeration cycle diagram of a conventionally well-known automobile air conditioner, Fig. 2 is an electric field diagram showing the capacity control circuit of the device shown in Fig. 1, and Fig. 3 is an evaporator using a conventionally well-known capacity control method. Characteristic diagram showing changes in internal refrigerant pressure and air temperature immediately after the evaporator, Fig. 4 +1+ is a configuration diagram showing the overall control system of the device of the present invention, Fig. 4 (b), tel senses the ambient temperature of the vehicle Fig. 5 is an electric circuit diagram showing a specific configuration of the control circuit 16 of the device of the present invention, Fig. 6(a), (bl is vg6 diagram) Fig. 7 is a sectional view showing an embodiment of the pressure Ml! used in the present invention, Fig. 8 is a sectional view showing the configuration of the compressor internal capacity variable member, Fig. 9 (
1) and (b) are explanatory diagrams showing the capacity adjustment mechanism of the compressor used in the present invention, FIG. 10 is a sectional view of a solenoid valve used in one embodiment of the present invention, and FIG. The electrical circuit diagram of the embodiment, Fig. 12 is the combination shown in Fig. 11.
FIG. 18 is a block diagram showing the overall control system of the second invention device, FIG. 14 is an electrical circuit diagram showing the specific configuration of the control circuit 15 of the second invention device, and FIG. Figure 15(a)
, OL (d) is the comparator 81. shown in FIG.
86.65, and FIG. 15(e) is a characteristic diagram of the frequency-voltage converter. FIG. 16 is an electric circuit diagram of another embodiment of the second invention. Figure 17(m) shows the comparator 81°4 shown in Figure 16.
Fig. 17 (b), (s))! @16
FIG. 6 is an operational characteristic diagram of the illustrated comparator 86.66; 6...Evaporator, 12...Fist compressor, 18...
...Electromagnetic clutch, 14.19...Temperature sensor. l6...Fist control circuit, 16...Solenoid valve. 18... Capacity variable member. Patent applicant Nippondenso Co., Ltd. Representative Patent Attorney Hiroshi Okawa Figure 4 (b) (C) Figure 9 Figure 10 Figure 15 (a) 1 (C) (b) 1 (d) i

Claims (1)

[Scope of Claims] (1) A method for controlling an automobile air conditioner having a compression mode configured to be able to change discharge capacity in stages, comprising:
It is characterized by sensing the temperature or refrigerant pressure related to the degree of cooling of the evaporator, as well as sensing the ambient temperature of the vehicle, and controlling the stepwise switching of the discharge capacity of the compressor and the operation stop in response to these rain detection signals. A method for controlling an air conditioner for an automobile. (8) When the ambient temperature of the vehicle is above the set temperature, the discharge capacity of the pressure S machine is set to a large capacity, and when the rnn humidity temperature is set, the high capacity operation and operation stop of the compressor are switched by the refrigerant pressure sensing signal.
- On the other hand, when the ambient temperature of the vehicle is below the set temperature, the discharge capacity of the compressor is set to a small capacity, and the compressor is switched between small capacity operation and operation stop according to the temperature or refrigerant pressure sensing signal. 2. A method for controlling an air conditioner for an automobile according to claim 1, wherein: (8) When the ambient temperature of the vehicle is higher than the set temperature, the temperature or refrigerant pressure sensing signal is used to control switching between high-capacity operation, small-capacity operation, and operation stop of compression. 2. The method of controlling an air conditioner for an automobile according to claim 1, wherein when the temperature is lower than a set temperature, the compressor is switched between small capacity operation and operation stop based on a sensing signal of the temperature or refrigerant pressure. (4) A method for controlling an automobile air conditioner having a compressor configured to be directly connected to an on-vehicle engine, driven by receiving power, and capable of changing discharge capacity in stages, the method comprising: In addition to sensing the temperature or refrigerant pressure related to the degree of cooling, it also senses the vehicle's ambient temperature or evaporator intake air temperature, and engine speed, and changes the compressor discharge capacity in stages according to these sensing signals. A method for controlling an air conditioner for an automobile, characterized by controlling operation stoppage. (5) When the ambient temperature of the vehicle or the temperature of the evaporator intake air is above the set concentration and when the engine speed is below the set speed, the discharge capacity of the compressor is set to a large capacity to maintain the cooling degree of the evaporator. The compressor is switched between high-capacity operation and operation stop based on the relevant temperature or refrigerant pressure sensing signal, while the compressor is switched off when the ambient temperature of the vehicle, the evaporator intake air temperature, or the engine speed is other than the above conditions. 1111 before setting the discharge capacity of the machine to a small capacity! Is the compressor activated by the sensing signal of temperature or cold pressure? 5. The method of controlling an air conditioner for an automobile according to claim 4, wherein control is performed to switch between small-capacity operation and operation stop. (6) When the ambient temperature of the vehicle or the evaporator intake air temperature is above the set temperature and when the engine rotation speed is below the general constant rotation speed, the compressor is operated at high capacity by the temperature or refrigerant pressure sensing signal. Controls switching between small capacity operation and operation stop,
On the other hand, when the ambient temperature or the evaporator suction air temperature or the engine speed of the above-mentioned devices is outside the above-mentioned conditions, the compressor is switched between small-capacity operation and operation stop based on the temperature or refrigerant pressure sensing signal. A method for controlling an air conditioner for an automobile according to claim 4.