JPH032683B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to capacity control of a refrigeration cycle used in automobile air conditioners and the like.

[Prior Art] A conventionally well-known automobile air conditioner has a vapor compression refrigeration cycle consisting of a compressor 1, a condenser 2, a receiver 3, an expansion valve 4, and an evaporator 5 as shown in FIG. The compressor 1 is driven by an automobile engine 30 via an electromagnetic clutch 7, a belt 31, and a pulley 32. And in such a configuration,
As the engine speed increases, the compressor speed increases. Therefore, when the compressor rotational speed 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 frost adheres to the fins or freezes, the amount of air blown by the blower 8 decreases, and the cooling capacity decreases. Therefore, in order to prevent this frosting phenomenon and to control the temperature inside the vehicle interior, the air temperature immediately after the evaporator 5 is detected by a temperature sensor 6 such as a thermistor, and the control circuit 9 shown in FIG. By opening and closing the contacts 10a, the electromagnetic clutch 7 of the compressor 1 is turned on and off, and the operating time of the compressor 1 is adjusted to control the evaporation temperature of the refrigerant, and also to control the air temperature immediately after the evaporator. I'm trying to control it. Furthermore, since the engine 30 and the compressor 1 are directly connected, if the electromagnetic clutch 7 is connected when the car accelerates, the acceleration performance of the car will deteriorate. Cutting is also done.

[Problem to be solved by the invention]

However, in the conventional configuration, in order to prevent frost formation on the evaporator 5 and improve acceleration performance, the clutch 7
is intermittent. Therefore, there was a problem that the air temperature immediately after the evaporator 5 fluctuated drastically.

That is, when the compressor 1 is stopped, the expansion valve 4 is closed and the supply of liquid refrigerant to the evaporator 5 is stopped, but the load from the outside of the evaporator 5 is always applied to the refrigerant inside the evaporator 5. Therefore, the pressure inside the evaporator 5 increases, the refrigerant superheat area inside increases, and the effective heat transfer area of the evaporator 5 decreases. As a result, the cooling capacity decreases and the air temperature immediately after the evaporator 5 increases. For this reason, stopping the compressor 1 during acceleration will significantly worsen the cooling sensation.

In addition, in the above configuration, if the cooling load decreases or the rotation speed of the compressor 1 increases while the compressor 1 is in operation, the compression function will be in a state of excess, and the cooling capacity will exceed the cooling load. It will be higher than that,
The air temperature immediately after the evaporator will drop. As a result, while the compressor 1 is under intermittent control, the air temperature immediately after the evaporator varies significantly between when the compressor 1 is stopped and when it is in operation, resulting in poor cooling feeling.

The present invention has been made in view of the above-mentioned problems, and uses a variable capacity type compressor that has a built-in capacity variable member that changes the discharge capacity, and uses a variable capacity compressor that changes the temperature or refrigerant pressure that indicates the degree of cooling of the evaporator. In addition to controlling the compressor capacity accordingly, when the acceleration of the vehicle is detected, the compressor capacity is forcibly reduced to a small capacity for a set time to prevent refrigerant pressure and temperature rise in the evaporator. The set time immediately after the start of acceleration, which prevents a sudden rise in air temperature immediately after the evaporator due to the compressor stopping, and which requires the most engine driving force to accelerate the car, is
It is an object of the present invention to provide a refrigeration cycle control device for an automobile that can reduce the compressor load on the engine, improve the acceleration performance of the automobile, and achieve a cooling feeling during acceleration.

[Means to solve the problem]

In order to achieve the above object, the present invention includes: a variable capacity compressor driven by an automobile engine and incorporating a variable capacity member that changes the discharge capacity; and a variable capacity compressor that senses the temperature or refrigerant pressure that indicates the degree of cooling of the evaporator. a sensor; a detection means for detecting acceleration of the vehicle; a drive device for driving the variable capacity member of the compressor; The drive device is actuated to control the discharge capacity of the compressor so as to bring the pressure to a predetermined target value, and when the acceleration of the automobile is detected in response to a signal from the detection means, the drive device is forcibly operated for a set time. The compressor operates the drive device to reduce the discharge capacity of the compressor and, after the set time, returns to the discharge capacity according to the sensing signal from the sensor.

[Action and effect]

According to the above configuration of the present invention, the control means controls the compressor capacity so that the temperature or refrigerant pressure, which usually indicates the degree of cooling of the evaporator, reaches a predetermined target value. As a result, the evaporator can be maintained in a proper operating state, and it is possible to suppress rapid fluctuations in the air temperature immediately after the evaporator due to the intermittent operation of the compressor as in the prior art.

On the other hand, the control means forcibly reduces the compressor capacity to a small capacity for a preset time when acceleration of the vehicle is detected, and after the set time, controls the capacity according to the sensing signal from the sensor. The discharge capacity is restored to the original capacity. This makes it possible to reduce the load placed on the car's engine to drive the compressor during the set time period immediately after the start of acceleration, when the engine's driving force is most needed for car acceleration, thereby improving the car's acceleration performance. can be improved. In addition, it responds to acceleration by reducing the capacity without intermittent operation of the compressor, and also limits the time for reducing the capacity to a preset time, and after the set time, the capacity increases according to the sensing signal from the sensor. By returning to control, for example, deterioration of the cooling feeling during a large cooling load can be minimized, and it is possible to achieve both acceleration performance and cooling feeling.

〔Example〕

The present invention will be described below with reference to embodiments shown in the drawings. Since the refrigeration cycle in the apparatus of the present invention may be the same as that shown in FIG. 1, the explanation will be omitted. FIG. 3 schematically shows the entire control system of the device of the present invention. Reference numeral 11 is a resin ventilation casing of an automotive air conditioner, inside which is installed the evaporator 5 shown in FIG. 1 and a motor-driven blower. 8 is provided. The left end side of the ventilation casing 11 communicates with 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 communicates with an air outlet (upper air outlet for cooling) into the vehicle interior via a heater unit (not shown). (lower air outlet for heating, etc.).

A compressor 12 is provided in the refrigerant circuit on the outlet side of the evaporator 5.
The compressor 12 is driven by an automobile engine 30 via an electromagnetic clutch 13, a belt 31, and a pulley 32. Further, the compressor 12 is configured as a variable capacity type having a built-in capacity variable member 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 5; 23 is a temperature sensor consisting of a thermistor for sensing the temperature of the refrigerant flowing in the piping of the evaporator 5; Installed inside the entrance/exit piping. 24 is the compressor 12
This is a position detection device that detects the position of the variable capacitance member built into the device, and consists of a potentiometer that is linked to the movement of the variable capacitance member. 15 is a setting resistor that determines the control value (target value) of the air temperature immediately after the evaporator. 16 is a control circuit, and each of the above-mentioned elements 14, 15,
Signals 23 and 24 are input. That is, the above-mentioned elements 14, 23, and 24 are connected in series, and the potential at the connection point A between this series circuit and the setting resistor 15 is input to the control circuit 16.

Reference numeral 25 denotes an acceleration detection circuit of the automobile, and in this example, an on/off signal of an accelerator pedal switch 25a is inputted thereto. This switch 25a is configured to be turned on when the accelerator pedal is depressed by more than a set amount. In this example, the acceleration detection circuit 25 is configured to have a timer function, and its details will be explained in the fourth section.
As shown in the figure, when the switch 25a is turned on, the transistor 25c of the monostable multivibrator 25b is turned off for a certain period of time, and the transistor 25c is turned off for a certain period of time.
d is turned on. Then, when the transistor 25c is turned off, the transistor 25e is turned on, the transistor 25f is turned off, and the output terminal 2
It is designed to output “Hi” level output to 5g. And monostable multivibrator 25b
After a certain period of time determined by
The states of 5c, 25d, 25e, and 25f are inverted so that a "Lo" level output is output to the output terminal 25g. This enables temporary acceleration by pressing the accelerator pedal, such as accelerating the car by depressing the accelerator pedal beyond the set value, and then returning the accelerator pedal to below the set value, and when accelerating the car by depressing the accelerator pedal beyond the set value. It is possible to distinguish between continuous high-speed driving (high-speed driving) when the vehicle accelerates and then continues to operate the accelerator pedal at high speed while keeping the accelerator pedal depressed above a set value.

The operating characteristics of the acceleration detection circuit 25 configured in this way are as shown in FIG. 14, and the output is kept at the "Hi" level for a predetermined period of time after the switch 25a is turned on both during acceleration and at high speeds, and especially at high speeds. Even if the switch 25a remains on, the output can be set to the "Lo" level after a predetermined period of time. The output of this acceleration detection circuit 25 is also applied to the control circuit 16.

Reference numeral 17 denotes a servo motor for driving the variable capacity member within the compressor 12, which is controlled by the output of the control circuit 16.

18 is a worm gear for transmitting the driving torque of the servo motor 15 to the variable capacity member of the compressor 12.

Reference numeral 19 denotes a relay contact for on/off operation of the compressor 12, which is used to turn off/on energization of the electromagnetic clutch 13. 20 is a control circuit, which controls the engine speed,
It senses the outside temperature, etc., and opens the relay contact 19 when this temperature drops. 21 is an operating switch for the air conditioner, and 22 is an on-vehicle power battery.

FIG. 5 shows a specific example of the control circuit 16, which has two comparators 161 and 162 that receive as input the potential at the connection point A between the setting resistor 15 and the series circuit. Reference potential V ₁ of comparator 161
is set higher than the reference potential V ₂ of the second comparator 162. The difference between the reference potentials V ₁ and V ₂ can be freely adjusted using the variable resistor 163. The output 161a of the first comparator 161 causes the transistor 16
4a and 164b are turned on and off, and the second comparator 1
Transistor 165 by output 162a of 62
is turned on and off. 166 to 171 are transistors for driving the servo motor 17.

The output terminal 25g of the acceleration detection circuit 25 is connected to the resistor 17.
2 and 173, and are connected to the bases of transistors 164a and 165 via diodes 174 and 175.

FIG. 6 illustrates the operating characteristics of the control circuit 16 in relation to the voltage at the connection point A. The control circuit 16 controls the thermistor resistance value R 14 of the temperature sensor _14.
The potential at the connection point A changes depending on the total series resistance R _S of the thermistor resistance value R ₂₃ of the temperature sensor 23 and the potentiometer resistance value R ₂₄ of the position detection device 24 and the resistance value R ₁₅ of the setting resistor 15. The servo motor 17 is operated so that V _A is between the reference potentials V ₁ and V ₂ .
It controls the rotation of.

When the potential V _A of the first comparator 161 exceeds the reference potential V ₁ , its output 161a changes from the "Lo" level to the "Hi" level, and conversely, the potential V _A becomes the reference potential V1.
When V ₁ becomes smaller than V 1 by a certain value V _C , the output 1
61a returns from the "Hi" level to the "Lo" level. Here, the hysteresis characteristic indicated by the constant value V _C is set by the resistance value of the feedback resistor connected to the first comparator 161.

When the potential V _A of the second comparator 162 exceeds the reference potential V ₂ , its output 162a changes from the "Lo" level to the "Hi" level, and conversely, the potential V _A becomes the reference potential V2.
When the output a becomes smaller than V ₂ by a certain value V _C
returns to the “Lo” level from the “Hi” level.
Here, the hysteresis characteristic indicated by the constant value V _C is set by the resistance value of the feedback resistor connected to the second comparator 162. Also, the reference potential V ₂ is
It is set equal to the potential V _A when R _S and R ₁₅ become equal at a predetermined resistance value (R _S =R ₁₅ =predetermined resistance value).

Next, the configuration and operation of the variable displacement compressor 12 according to the present invention will be described in detail.

7 to 9, 101 is a shaft, and the electromagnetic clutch 13 shown in FIG.
The engine 30 is connected to an automobile engine 30 serving as a driving source via a belt 31 and a pulley 32.
It is rotated by the driving force of. Reference numeral 102 denotes a swash plate that is fixed to the shaft 101 with a key and rotates together with the shaft 101.
04 is reciprocated. Housings 105 and 106 have a cylinder portion 107 that supports the reciprocating motion of the piston 104, and are divided into two parts, front and rear, and die-cast from aluminum or the like. 108 is a suction passage chamber formed within the housings 105 and 106. As shown in FIGS. 8 and 9, the cylinder portion 107 is located at five locations 107a, 107b, 107c, 107d,
07e is formed, and the lowermost cylinder part 10
There is a gap of 88° only between 7c and 107d, and the spacing between other cylinder parts is
It is designed to be 68°. Further, the suction passage chamber 108 is arranged in each cylinder portion 107 as shown in FIG.
All of the suction passage chambers 108 are connected to one refrigerant inlet (not shown), and communicate with the refrigerant circuit on the outlet side of the evaporator 5 via this inlet. Reference numerals 109 and 110 denote side housings, which are disposed outside the housings 105 and 106 with valve plates 111 and 112 in between.
A suction chamber 113 is formed in a portion that directly communicates with the side housings 109 and 112 through suction side communication holes (not shown), and the side housings 109 and 11
0, the piston 10 on the inner periphery of the suction chamber 113
A discharge chamber 114 is formed at a position facing 4. This discharge chamber 114 is connected to the valve plate 11
It communicates with the discharge passage chamber 114a (FIG. 9) of the housing 105, 106 through a discharge side communication hole (not shown) numbered 1,112. 115, 116 are valve plates 111, 112 and housings 105, 10
A disc-shaped elastic metal plate made of an elastic metal, for example, spring steel, interposed between the elastic metals 115 and 116.
A U-shaped notch (not shown) is provided at a position facing the piston 104 to form a suction valve.
In addition, housings 105, 106, side housings 109, 110, and valve plates 111,
112 are integrally connected by a through bolt 117, and the through bolt 117 passes through the suction passage chamber 108 within the housings 105, 106 to facilitate assembly.

118 and 119 are radial bearings using normal needle bearings, and housing 1
An outer race is fixed to 05 and 106 to rotatably hold the shaft 101. 1
Thrust bearings 20 and 121 are located between the center portions of the housings 105 and 106 and the swash plate 102, so that the force applied to the swash plate 102 in the thrust direction (axial direction), that is, the swash plate 102
This supports the reaction force received when the 04 is reciprocated.

A shaft seal 122 is located between the shaft 101 and the side housing 109, which is located on the driving source side (in other words, on the electromagnetic clutch 103 side) of the side housings 109, 110, and seals the refrigerant gas and lubrication inside the compressor. It maintains airtightness to prevent oil from leaking to the outside.

Reference numeral 123 denotes a holder for the servo motor 17, which is fixed to the rear side housing 110 with screws 124. Worm gear 18 of servo motor 17
is connected to an operating shaft 126 by a worm gear 125, as shown in FIG. This operating shaft 1
26 utilizes the space between the lowermost cylinder parts 107c and 107d to attach the rear valve plate 11.
Spur gears 127 and 128 are disposed between the valve plate 111 and the valve plate 111 on the front side, and are attached to portions of the operating shaft 126 adjacent to the valve plates 111 and 112, respectively. 1
Reference numerals 29 and 130 are annular variable rings that constitute variable capacity members;
130 is disposed in a cylindrical space provided on the outer periphery of the cylinder portion 107 in the housings 105 and 106 so as to be concentric with the compressor drive shaft 101. The rotational force of the operating shaft 126 is transmitted to the variable rings 129, 130 via spur gears 127, 128 and teeth 129a, 130a provided on the inner circumference of the variable rings 129, 130, so that the rings 129, 130 rotate. ing.

Two bypass holes 131a and 131b are provided in the wall surface of each cylinder portion 107 at positions closest to the variable rings 129 and 130, and these bypass holes 131a and 131b are located on the inner periphery of the variable rings 129 and 130. Bypass grooves 132a and 132b provided in the circumferential direction on the surface, bypass grooves 133 arranged in parallel to the shaft 101 in the variable rings 129 and 130, and the variable ring 12
The inner peripheral surfaces of the compressors 9 and 130 communicate with a bypass port 135 formed in the housings 105 and 106 through a bypass groove 134 provided all around the center side of the compressor.
Furthermore, this bypass port 135 is connected to the housing 10.
5, 106 is formed so as to be electrically connected to the suction passage chamber 108 provided in the suction passage chamber 106.

In this embodiment, the bypass holes 131a and 131b drilled in the wall surface of the cylinder 107 are arranged at positions that divide the cylinder volume into three equal parts, and either only the port 131b on the center side of the compressor, or both the ports 131a , 131b are arranged to face the bypass grooves 132a, 132b in accordance with the rotation angle of the variable rings 129, 130 (see FIGS. 10 and 11).

Further, the bypass grooves 132a, 132b are connected to the five cylinders 107a, 107b, 107c, 107.
d and 107e, respectively, as shown in FIG.
The cylinders 10 are provided with different lengths in the circumferential direction of the cylinders 30 and communicate with the suction passage chamber 108 according to the rotation angle of the variable links 129 and 130.
It has been devised so that the number of 7s is different. That is,
In the case of this embodiment, when the rotation angle is 0°, all the bypass holes 131a and 131b (20 holes in total) are located so as to directly oppose the bypass grooves 133 of the variable rings 129 and 130, and the bypass grooves 133, It is connected to the suction passage chamber 108 via the bypass groove 134 and the bypass ports 135 of the housings 105 and 106, and the cylinder volume that performs the net compression work is minimized. When the rotation angle is 4 degrees, only the bypass hole 131a provided in the cylinder portion 107e is not in communication with the bypass groove 132a, and the remaining bypass holes 131a, 131b are not in communication with the bypass groove 132a.
Both are in communication with the suction passage chamber 108.

Thereafter, as the rotation angle increases by 4 degrees such as 8 degrees, 12 degrees, etc., the number of bypass holes that do not communicate with the suction passage chamber 108 increases one by one, and when the rotation angle is 36 degrees,
Bypass hole 131 provided in cylinder 107a
Only the hole a is in communication with the suction passage chamber 108 via the bypass groove 132b, and the others are not in communication. When the rotation angle reaches 40 degrees, all the bypass holes 131a and 131b are closed, and due to compression work. The cylinder volume of is maximum. This variable ring 1
The relationship between the rotation angle of 29,130 degrees and the cylinder volume that does the net compression work is shown in Figure 13, and the cylinder volume is finely reduced in 10 steps between the maximum volume Vmax and 1/3Vmax. Can be controlled.

The rotational positions of the variable rings 129 and 130 can be detected as electrical signals by the potentiometer of the position detection device 24.
That is, the worm gear 125 formed on the end surface of the operating shaft 126 is connected to the operating gear 241 of the position detection device 24.
The operating shaft 126
The potentiometer resistance value of the position detection device 24 is varied according to the rotation of the worm gear 125,
As a result, an electric signal determined depending on the position of the variable rings 129, 130 is output. The position detection device 24 is fixed to the side housing 110 with screws 243 via a stay 242 formed on the side surface thereof. Note that storage grooves are formed in the side housing 110 at the portion where the position detection device 24 is held and the portion where the servo motor 17 described above is held, so that the servo motor 17, the position detection device 24, etc. In addition to ensuring more secure retention, side housing 1
The servo motor 17 and the like are made not to protrude too much from the surface 10. Although not shown, a servo motor 17, worm gears 18, 12
5. The position detection device 24 and the like are covered with a cover (not shown) to prevent dust.

Next, to explain the operation of only the swash plate compressor 12, when the electromagnetic clutch 13 is connected and the shaft 1 and swash plate 2 begin to rotate, the refrigerant gas vaporized in the evaporator 5 is transferred to the housings 105 and 106.
Suction passage chamber 1 is introduced from an inlet (not shown) provided in
08, valve plates 111, 112
It flows into the suction chamber 113 of the front and rear side housings 109, 110 through the suction side communication hole (not shown). When the piston 104, which reciprocates within the cylinder portion 107 as the swash plate 102 rotates, enters the suction stroke, the refrigerant gas is introduced into the elastic metal plate 11 from the suction ports in the valve plates 111 and 112.
5, 116 into the cylinder portion 107. Next, the piston 104
When the engine moves to the compression stroke, the suction port is closed by the suction valve, the refrigerant gas in the cylinder portion 107 is compressed by the piston 104, and the valve plate 1
11, 112 discharge ports and discharge valves (not shown)
is discharged to the discharge chamber 114 inside the side housings 109, 110, and then to the valve plate 11 again.
It flows into the discharge passage chamber 114a in the housings 105, 106 through the discharge side communication holes (not shown) at 1,112, and then is heated to high temperature during the compression stroke of the piston 104.
The high-pressure refrigerant gas is transferred to the housings 105 and 10.
It is sent to the condenser 2 from a discharge port 6 (not shown).

During the above operation, the rotational speed of the shaft 101 is varied according to the engine rotational speed, so the discharge capacity of the compressor 12 also increases or decreases depending on the engine rotational speed, and when the engine is at high rotational speed, etc. In this case, a situation may occur in which the discharge capacity of the compressor 12 becomes abnormally larger than the capacity required by the operating state of the refrigeration cycle. However, in the compressor 12 of the present invention, in such a state where the discharge capacity becomes excessive, the discharge capacity of the cylinder 107 is reduced to reduce the discharge capacity.

Therefore, the operation of the control circuit that controls the capacity (net cylinder volume) of the compressor 12 will be explained below. The air temperature immediately after the evaporator is sensed by the sensor 14, and when the sensed temperature increases due to an increase in the cooling load, the thermistor resistance value _R14 of the sensor 14 increases.
decreases, resulting in total series resistance R _S (=R ₁₄ + R ₂₃ +
R ₂₄ ) decreases, and the potential V _A decreases. In FIG. 6, when V _A becomes smaller than (V ₂ - V _C ), the output 162a of the second comparator 162 is inverted from the "Hi" level to the "Lo" level, and the transistor 165
is turned off, so transistors 168, 169,
170 is turned on. At this time, as can be seen from the characteristics in FIG. 6, the output 161a of the first comparator 161
is at “Lo” level, and the transistor 164a
is off and transistor 164b is on, so transistors 166, 167, and 171 are off. As a result, current flows to the servo motor 17 through the emitter-collector of the transistor 170 and the collector-emitter of the transistor 169, and the servo motor 17 rotates in the forward direction. 128, and variable rings 129 and 130 rotate clockwise in FIG. 9, the variable ring 12 defined in FIG.
9,130 rotation angle increases and the net cylinder volume increases. Therefore, the compression power increases and the air temperature immediately after the evaporator gradually decreases. As a result, the resistance value R ₁₄ of the sensor 14 gradually increases, and at this time, the position detection device 24 also operates simultaneously with the rotation of the variable rings 129 and 130, and its resistance value R ₂₄ increases. As a result, R _S increases and the potential V _A
to rise. Eventually, when the potential V _A becomes higher than V ₂ , the output 162a of the second comparator 162 becomes "Hi" level, and the transistor 165 turns on, so that the transistors 168, 169,
170 is turned off. At this time, the first comparator 16
Since the output 161a of the transistor 1 is still at the "Lo" level, the transistors 166, 167, and 171 continue to be off. Therefore, the servo motor 17
The power to the servo motor 17 is stopped, and the servo motor 17 is stopped.
The positions of the variable rings 129, 130 are maintained, and the compressor capacity is determined according to the set value.

On the other hand, when the air temperature immediately after the evaporator decreases due to a decrease in the cooling load (a decrease in the evaporator suction air temperature, etc.), the thermistor resistance value _R14 of the sensor 14 increases, and as a result, R _S increases and the potential V _A rises. V _A
When becomes larger than V ₁ , the output 161a of the first comparator 161 changes from the "Lo" level to the "Hi" level, turning on the transistor 164a and turning off the transistor 164b.
66, 167, 171 are turned on. This results in
A current in the opposite direction flows through the servo motor 17 through the emitter and collector of the transistor 171 and the collector and emitter of the transistor 167, causing the servo motor 17 to rotate in the opposite direction, and through the worm gear 18 to the worm gear 125 and the operating shaft 1.
26, spur gears 127, 128, variable ring 12
9,130 rotates counterclockwise in FIG.
Since the variable ring rotation angle in Figure 2 is reduced, the compressor capacity is reduced. As a result, the air temperature immediately after the evaporator rises, and the resistance value _R14 of the sensor 14 decreases.
Further, at this time, the position detection device 24 is also activated and its resistance value R ₂₄ decreases, and as a result, R _S decreases. When V _A decreases due to this decrease in R _S and becomes smaller than V ₁ - V _C , the output 16 of the first comparator 161
1a becomes “Lo” level, and transistor 16
4a turns off, transistor 164b turns on, transistors 166, 167, and 171 turn off, servo motor 17 stops again, and the positions of variable rings 129 and 130 are maintained.

In the above operation, the position detection device 24 constantly detects the rotational position of the variable rings 129, 130 and provides negative feedback to the input side of the control circuit 16, thereby preventing excessive rotation of the variable rings 129, 130, Servo motor 17, variable ring 129,1
Prevent 30 hunting. Moreover, this also makes it possible to minimize overshoot and undershoot in evaporator temperature control.

On the other hand, in an automobile air conditioner, the compressor 12
Because it is driven by a car engine,
The rotational speed of the compressor 12 will vary significantly as the driving conditions of the vehicle change. Furthermore, since the condenser 2 is generally installed to receive cooling air generated by the ram pressure of the automobile, the condenser capacity will also vary depending on changes in the driving conditions of the automobile. Therefore, although the driving conditions of the automobile become a disturbance factor for evaporator temperature control, there is a correlation between fluctuations in refrigerant flow rate due to fluctuations in compressor rotation speed, fluctuations in condenser capacity, etc., and refrigerant temperature in the evaporator section. Therefore, in the present invention, focusing on this point, the sensor 2 detects the refrigerant temperature in the evaporator section.
3 and input it to the control circuit 16, it is possible to set the compressor capacity corresponding to the refrigerant temperature in the evaporator section, thereby stabilizing the control of the compressor capacity. There is no need to frequently move the rotational position of the evaporator, and the temperature of the evaporator can be controlled smoothly.

On the other hand, the output of the acceleration detection circuit 25 is also added to the control circuit 16, and when the accelerator pedal is currently depressed to accelerate the car and the amount of depression exceeds a set amount, the accelerator pedal switch 25a is activated. As a result, the output of the acceleration detection circuit 25 becomes "Hi" level for a certain period of time T as shown in FIG. 14, and the transistors 164a and 165 of the control circuit 16 are forcibly turned on. As a result, transistor 164
a turns off, transistors 166, 167, 17
1 is turned on, while transistors 168, 169,
170 is turned off, current flows to the servo motor 17 through the emitter-collector of the transistor 171 and the collector-emitter of the transistor 167, the servo motor 17 rotates in the opposite direction, and the variable ring rotation angle shown in FIG. 12 decreases. Compressor capacity is reduced. In this case, comparators 161 and 162
Since the servo motor 17 rotates in reverse regardless of the output of the compressor, the compressor capacity is set to the minimum capacity (1/3 Vmax), the engine load is reduced, and the automobile is smoothly accelerated. Moreover, since the compressor 12 continues to operate even during acceleration, there is little variation in the air temperature immediately after the evaporator, and the cooling sensation does not deteriorate.

Further, during high-speed driving, the switch 25a is always on, but after the above-mentioned fixed time T has elapsed, the output of the acceleration detection circuit 25 changes as shown in FIG. 14 due to the action of the monostable multivibrator 25b.
Since the level becomes "Lo" and the capacity of the compressor 12 is appropriately controlled by the outputs 161a and 162a of the comparators 161 and 162, there will be no shortage of cooling during high-speed driving.

As described above, the compressor capacity is automatically controlled according to the operating status of the air conditioner, and is set to the optimal compressor capacity at that time. And sensor 1
4 is within the set temperature range (between potential V ₁ and potential V ₂ in the characteristic diagram of FIG. 6), the servo motor 17 is de-energized and the variable rings 129, 130 This position is maintained, and the compressor 12 continues to operate at a predetermined capacity.

When controlling the air temperature immediately after the evaporator to prevent frost in the evaporator 5, it is preferable to control the compressor capacity so that the air temperature falls within a range of, for example, 3°C to 5°C.

As mentioned above, by setting a range in the set temperature and stopping the servo motor 17 while the air temperature immediately after the evaporator is within the set temperature range, it is possible to prevent large fluctuations in cooling load and engine speed. However, since the operating time of the servo motor 17 can be reduced and its durability improved, and the set temperature range can be arbitrarily selected using the variable resistor 163, stable control can be achieved by changing the set range according to the degree of load fluctuation, etc. can be done.

In addition, as mentioned above, temperature control is performed by finely variable control of the compressor capacity, so
The compressor 12 can be kept rotating without disconnecting the electromagnetic clutch 13 in a wide range of operating conditions of the air conditioner, and as a result, the clutch 13 and the compressor 1 can be kept rotating without disconnecting the electromagnetic clutch 13.
It is possible to prevent deterioration of durability and deterioration of running feeling as described in No. 2. Moreover, the electromagnetic clutch 1
It is possible to prevent the deterioration of the feeling of cooling caused by the delay in the intermittent operation of the compressor 12, and at the same time, there is no need to rotate the compressor 12 unnecessarily while maintaining its high capacity, resulting in overall power savings. Furthermore, in conventional cooling capacity control that intermittents the compressor, when the compressor is stopped, the inside of the evaporator 5 immediately becomes overheated, and even when the compressor is started again, the evaporator 5 remains in the overheated region until the overheated region is removed. During this time, the power to operate the compressor was essentially wasted, but with a system that controls the cooling capacity without stopping the compressor, as in the conventional method, the evaporation Since the compressor is not overheated, the compressor is not operated unnecessarily as described above.

In addition, in the above-mentioned embodiment, the bypass holes 131a and 131b of the cylinder 107 are connected to the bypass groove 132.
a, 132b, 133, 134, etc., but the communication destination may be any space as long as the pressure is lower than the internal pressure of the cylinder 107, in other words, the space where the internal pressure is the suction pressure. ,
Depending on the shape of the compressor, this communication destination may be connected to the suction chamber 1.
13, the crank chamber (rotation space of the swash plate 2), or another cylinder 107 in the suction stroke.

Further, in the above embodiment, a 10-cylinder swash plate compressor is used, but it goes without saying that any swash plate compressor having a plurality of cylinders may be used. Further, in the above embodiment, the variable ring 129,
130 is disposed in the cylindrical space on the outer periphery of the housings 105 and 106, but it goes without saying that it may also be disposed between the compressor drive shaft 101 and each cylinder 107.

Further, as long as the compressor 12 is of a variable displacement type, it is not limited to the swash plate type, and other types such as a vane type can be used.

In addition, the variable capacity members are variable rings 129, 13.
The configuration is not limited to 0, and can be changed to various configurations depending on the type of compressor, etc.

In addition to the servo motor 17, a combination of a negative pressure diaphragm mechanism and a link mechanism may be used as the drive device.

Further, in the above-described example, the air temperature immediately after the evaporator was detected as the temperature on the air side of the evaporator 5, but the surface temperature of the evaporator may also be detected. Also,
The evaporator part refrigerant pressure may be detected instead of the evaporator part refrigerant temperature.

In addition, a setting resistor 15 is provided on the control panel of the air conditioner so that the user can manually operate the setting resistor 15.
If the user is allowed to freely set the resistance value _R15 of 5, the room temperature can be controlled by controlling the capacity of the compressor.

Further, the acceleration state of the automobile can also be detected by electrically detecting the vehicle speed and differentiating the vehicle speed signal, and various means can be used to detect the acceleration.

[Brief explanation of drawings]

FIG. 1 is a refrigeration cycle diagram of a conventionally known automotive air conditioner, FIG. 2 is a schematic diagram of the ventilation system of the device shown in FIG. FIG. 4 is an electric circuit diagram illustrating a specific configuration of the acceleration detection circuit 25 in the present invention.
FIG. 6 is an electric circuit diagram illustrating the specific configuration of the control circuit 16 of the device of the present invention, FIG. 6 is an operating characteristic diagram of the comparators 161 and 162 shown in FIG. 5, and FIG. 7 is a diagram of the compressor used in the present invention. 9 is a side view of the same compressor, and FIG. 9 is a sectional view taken along line A-A in FIG. 7. , FIG. 10 shows the relationship between the bypass hole and the bypass groove of the variable ring, and FIG. 10 is a diagram showing the positional relationship of each bypass groove provided in the variable ring. Figure 11 shows C- in Figure 10.
12 is a cross-sectional view showing the shape of the bypass groove corresponding to each cylinder; FIG. 13 is an explanatory view showing the relationship between the rotation angle of the variable ring and the net cylinder volume that performs compression work; FIG. 14 is an operational characteristic diagram of the acceleration detection circuit 25 shown in FIG. 4. 5... Evaporator, 8... Air blower, 11... Ventilation casing, 12... Compressor, 14, 23... Temperature sensor, 1
5... Setting resistor, 16... Control circuit, 17... Servo motor forming a drive device, 24... Position detection device, 25
... Acceleration detection circuit, 30 ... Automobile engine, 12
9,130...Variable ring forming a variable capacity member.

Claims (1)

[Scope of Claims] 1. A variable capacity compressor driven by an automobile engine and incorporating a variable capacity member that changes the discharge capacity; A sensor that detects temperature or refrigerant pressure indicating the degree of cooling of the evaporator; a detection means for detecting acceleration of the automobile; a drive device for driving the variable capacity member of the compressor; and a drive device for driving the variable capacity member of the compressor; The drive device is operated to control the discharge capacity of the compressor so as to achieve a target value, and when the acceleration of the automobile is detected in response to a signal from the detection means, the drive device is forcibly operated for a set time. A refrigeration cycle for an automobile, comprising: control means for operating the compressor to reduce the discharge capacity of the compressor and, after the set time, returning the discharge capacity to the discharge capacity according to a sensing signal from the sensor. Control device.