JPH0127893B2 - - Google Patents

Description

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

A conventionally known air conditioner for an automobile 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.

However, in such a configuration, if the engine start switch is connected while the air conditioner switch is turned on, the electromagnetic clutch will be connected and the compressor will operate together with the engine.
Therefore, a relatively large load is applied to the engine (approximately 30% of the engine output at startup), which has the disadvantage of worsening startability.

Also, when the car is running after the engine has started,
Even when turning on the air conditioner switch, clutch 7
At the moment when the
This has the disadvantage that a shock is felt while driving, which deteriorates the running feel, and furthermore, a large frictional torque is added to the friction surface of the electromagnetic clutch, shortening the life of the electromagnetic clutch.

Therefore, in order to eliminate the above-mentioned drawbacks, the inventors of the present invention first used a compressor 1 equipped with a variable capacity mechanism, and reduced the compressor capacity to a small capacity when the engine start switch was turned on, thereby reducing the load applied to the engine at the time of starting. The engine is made smaller to improve engine starting performance, and the compressor starting torque associated with electromagnetic clutch connection is reduced to improve running feeling.
The idea was to extend the life of the clutch by reducing the large frictional torque when the clutch is engaged.

However, when such a structure is adopted, cooling is always started with the compressor at its minimum capacity, and even when the cooling load is large, such as in the middle of summer, only the minimum cooling capacity can be exerted, and the cooling speed is reduced rapidly. This means that there will be no air conditioning.

The present invention has been devised in view of the above points, and includes improved engine startability, improved running feeling,
It is an object of the present invention to extend the life of the clutch, and at the same time, to improve the feeling of cooling by performing initial rapid cooling.

In order to achieve this object, the present invention uses a compressor equipped with a variable capacity mechanism and a means for controlling the capacity, and when the engine start switch is turned on, the compressor capacity is reduced to a small capacity, and then the electromagnetic The clutch is connected to prevent deterioration of engine startability and shock while driving.Next, when the compressor starts operating, the variable capacity mechanism is activated so that the compressor capacity increases. The air conditioner is configured to hold the capacity for a certain period of time and operate the air conditioner at a large cooling capacity to perform initial rapid cooling and improve the feeling of cooling.

The present invention will be described below with reference to 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. 2 schematically shows the entire control system of the device of the present invention. Reference numeral 11 is a resin ventilation casing of an automobile air conditioner, and inside it there is an 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. Reference numeral 24 denotes a position detection device for detecting the position of the variable capacity member built into the compressor 12, and is composed of a potentiometer that is linked to the movement of the variable capacity member. 15 is a setting resistor that determines the control value of the air temperature immediately after the evaporator, and 16 is a control circuit to which signals from the above-mentioned elements 14, 15, 23, and 24 are input. That is, the above-described 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 the control circuit 1.
6 is set to be input.

18 is a worm gear for transmitting the driving torque of the servo motor 17 to the variable capacity member of the compressor 12.

Reference numeral 19a is a relay contact for turning on and off the operation of the compressor 12, and is used to turn on and off the energization of the electromagnetic clutch 13. 19b is a coil that closes the relay contact 19 when energized. Also, 25
is a time limit circuit that delays the operation of the coil 19b to close the contact 19a for a predetermined period of time, and continues to output a signal to increase the capacity of the compressor 12 for a predetermined period of time when the contact 19a is closed. 21
2 is an operating switch for the air conditioner, and 22 is an on-vehicle power battery. 20 is a switch that is turned on when the engine 30 is started, such as an ignition switch.

FIG. 3 shows a specific example of the circuit 16 and time limit circuit 25 that constitute the controller of the present invention.
The control circuit 16 includes two comparators 16 that receive the potential at the connection point A between the setting resistor 15 and the series circuit.
1,162, and the reference potential V ₁ of the first comparator 161 is 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. Transistors 164a and 164b are turned on and off by the output 161a of the first comparator 161, and the second
The transistor 165 is turned on and off by the output of the comparator 162 162a. 166 to 171 are transistors for driving the servo motor 17.

When the ignition switch 20 is closed,
The capacitor 250 of the time limit circuit 25 is charged.
When the charging voltage of the capacitor 250 becomes higher than the reference potential _V3 after a predetermined time t has elapsed, the output 251a of the comparator 251 reverses from the "Lo" level to the "Hi" level, so the transistor 252 turns on.
Transistor 253 turns off, transistor 25
4 turns on. When the transistor 254 is turned on, current flows through the coil 19b, closing the relay contact 19a and energizing the electromagnetic clutch 13.

Before the predetermined time t has elapsed, the voltage on the capacitor 250 has not yet increased, and the transistor 252
When 255,2 is off, the collector voltage is
56 and diodes 172, 173 to the bases of transistors 165, 164a, and forcibly turns on transistors 165, 164a.

When the relay contact 19a is closed and the electromagnetic clutch 13 is energized, the output 262a of the comparator 262 is at the "Lo" level until a certain time Z due to the time limit circuit set by the resistor 260 and the capacitor 261. . When the output 262a is at the "Lo" level, the transistor 263 is turned off, and voltage is applied to the bases of the transistors 164b and 168 via the resistors 264 and 265, forcing the transistors 164b and 168 to be turned on. When the output 262a of the comparator 262 is reversed to the "Hi" level after a predetermined time Z has elapsed, the transistor 263 is turned on, and voltage is no longer applied to the bases of the transistors 164b and 168 from the resistors 264 and 265. Therefore, the transistors 164b and 168 are no longer forced to be turned on, and the servo motor 17
It comes to operate in response to signals from 23 and 24.

FIG. 4 shows the operating characteristics of the control circuit 16, which controls the thermistor resistance value R ₁₄ of the temperature sensor 14, the thermistor resistance value R ₂₃ of the temperature sensor 23, and the potentiometer of the position detection device 24. The rotation of the servo motor 17 is controlled so that the total series resistance Rs of the resistance value R ₂₄ is balanced with the resistance value R ₁₅ of the setting resistor 15, and the first comparator 161
The total series resistance Rs is the resistance value of the setting resistor 15 R ₁₅
When the resistance value of the variable resistor 163 increases by R ₁₆₃ , that is, when it becomes Rs + R ₁₆₃ , the output 161
When a becomes "Hi" level than "Lo" level, and conversely, Rs becomes smaller than R ₁₅ + R ₁₆₃ by a certain value Rc, that is, when Rs<(R ₁₅ + R ₁₆₃ ) - Rc, the output 161a becomes "Hi". It is starting to return to the “Lo” level.

On the other hand, the output 162a of the second comparator 162 changes from the "Lo" level to the "Hi" level when Rs= _R15 , and conversely, when Rs becomes smaller than _R15 by the constant value Rc, that is, Rs< _R15 . -Rc, the output 162a returns from the "Hi" level to the "Lo" level. Rc is a constant resistance value width due to the hysteresis characteristics of the first and second comparators 161 and 162.

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

In FIGS. 5 to 7, 101 is a shaft, and an electromagnetic clutch 13 and a V-belt 3
1. It is connected via a pulley 32 to an automobile engine 30 serving as a driving source, and is rotated by the driving force of the engine 30. 102 is the shaft 101
This is a swash plate that is fixed by a key to the shaft 101 and rotates together with the shaft 101. The rotation of this swash plate 102 causes a piston 104 to reciprocate via a shoe 103. 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. 6 and 7, the cylinder portion 107 is located at five locations 107a,
107b, 107c, 107d, 107e are formed, and the lowermost cylinder portions 107c and 107
There is a gap of 88 degrees only between the cylinder parts d and 68 degrees between the other cylinder parts.

Further, the suction passage chamber 108 is formed between each cylinder part 107 as shown in FIG. It communicates with the outlet side refrigerant circuit of No. 5.

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 of the side housings 109 and 110 that directly communicate with each other through a suction side communication hole (not shown), and a portion of the side housings 109 and 110 that faces the piston 104 on the inner periphery of the suction chamber 113 is formed. A discharge chamber 114 is formed at the position. This discharge chamber 114 is connected to the housing 10 through the discharge side communication holes (not shown) of the valve plates 111 and 112.
It communicates with the discharge passage chamber 114a (FIG. 7) of No. 5,106.

115, 116 are valve plates 111, 11
2 and the housings 105, 106, the piston 1 of the elastic metal plates 115, 116 is
Although not shown, a U-shaped notch is formed at a position facing 04 to form a suction valve. In addition, housings 105, 106, side housings 109, 11
0 and the 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. ing.

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 reciprocating the 04.

122 is a shaft seal, and the side housing 1 is located on the drive source side (in other words, on the electromagnetic clutch 13 side) among the side housings 109 and 110.
09 and the shaft 101 to maintain airtightness so that the refrigerant gas and lubricating oil inside the compressor do not leak 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 on the front side 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.

Reference numerals 129 and 130 are annular variable rings that constitute variable capacity members;
9,130 is housing 105,106,
It is disposed in a cylindrical space provided on the outer periphery of the cylinder portion 107 so as to be concentric with the compressor drive shaft 101 . The rotational force of the operating shaft 126 is applied to the variable rings 129, 130 through the spur gears 127, 128.
The rotation is transmitted through teeth 129a, 130a provided on the inner periphery of the variable rings 129, 130.

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 Figures 8 and 9) Furthermore, the bypass grooves 132a and 132b are connected to the five cylinders 107a, 107b, 107c, and 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 rings 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 (total 20
) is the bypass groove 1 of the variable rings 129, 130.
33, and the bypass groove 133, the bypass groove 134 and the housing 10
It is connected to the suction passage chamber 108 through 5,106 bypass ports 135, and the cylinder volume that performs the net compression work is minimized.

When the rotation angle is 4 degrees, the cylinder 107
Only the bypass hole 131a provided in e is not in communication with the bypass groove 132a, and the remaining bypass holes 131a and 131b are both connected to the suction passage chamber 1.
It is electrically connected to 08. After that, the rotation angle is 8°, 12°...
As the angle increases by 4 degrees, the number of bypass holes that do not communicate with the suction passage chamber 108 increases one by one.
When the rotation angle is 36 degrees, only the bypass hole 131b provided in the cylinder 107a is connected to the bypass groove 13.
2b to the suction passage chamber 108, and the others are not electrically connected. When the rotation angle reaches 40 degrees, all the bypass holes 131a and 131b are closed, and the cylinder volume for compression work is at its maximum. becomes.

The relationship between the rotation angle of the variable rings 129 and 130 and the cylinder volume that does the net compression work is shown in Figure 11, and the maximum volume Vmax and 1/3
The cylinder volume can be finely controlled in 10 steps between Vmax and Vmax.

The rotational positions of the variable rings 129 and 130 can be detected as electrical signals by potentiometers 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 2 of the position detection device 24.
41, and the operating shaft 12
6 (worm gear 125), the resistance value of the potentiometer of the position detection device 24 is varied, and as a result, an electric signal determined according to 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 of 10. Also, although not shown,
Servo motor 17, worm gears 18, 125,
The position detection device 24 and the like are covered with a cover 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.

When the piston 104 moves to the compression stroke, the suction port is closed by the suction valve, and the cylinder portion 107 is closed.
The refrigerant gas inside is compressed by the piston 104,
The side housing 10 passes through the discharge ports of the valve plates 111 and 112 and the discharge valve (not shown).
It is discharged into the discharge chamber 114 in the valve plates 111 and 110, flows again into the discharge passage chamber 114a in the housings 105 and 106 through the discharge side communication holes (not shown) of the valve plates 111 and 112, and then becomes high temperature and high pressure in the compression stroke of the piston 104. The refrigerant gas is sent to the condenser 2 through discharge ports (not shown) of the housings 105 and 106.

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 refrigerant cycle. However, in the compressor 12 of this configuration, 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 capacity control mechanism of the compressor 12 will be explained below. The air temperature immediately after the evaporator 5 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 decreases, and as a result, the aforementioned Rs (=
R ₁₄ +R ₂₃ +R ₂₄ ) decreases from the resistance value R ₁₅ of the setting resistor 15, and when Rs becomes smaller than (R ₁₅ −Rc) in FIG. 4 (Rs<R ₁₅ −Rc), the second comparator 1
The output 162a of 62 is “Lo” than “Hi” level.
Since the level is inverted and transistor 165 is turned off, transistors 168, 169, and 170 are turned on.

At this time, as can be seen from the characteristics in Figure 4, the first
The output 161a of the comparator 161 is at "Lo" level, and the transistor 164a is off and the transistor 164b is on, so the transistors 166, 167, and 171 are off. As a result, the servo motor 17 has a transistor 170.
emitter-collector and transistor 169
Current flows through the collector/emitter of the servo motor 17 to rotate in the forward direction, and the servo motor 17 rotates through the worm gear 18 to the worm gear 125, the operating shaft 126, the spur gears 127, 128, and the variable rings 129, 13.
0 rotates clockwise in FIG. 7, the rotation angle of variable rings 129, 130 defined in FIG. 10 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 _R14 of the sensor 14 gradually increases.

At this time, the position detection device 24 also
It operates at the same time as 29,130 rotations, and its resistance value
R ₂₄ increases so that Rs becomes the resistance of the setting resistor 15
When it becomes larger than R ₁₅ (Rs>R ₁₅ ), the output 162a of the second comparator 162 becomes "Hi" level,
Since transistor 165 is turned on, transistors 168, 169, and 170 are turned off. At this time, since the output 161a of the first comparator 161 is still at "Lo" level, the transistor 16
Nos. 6, 167, and 171 continue to be in the off state.
Therefore, the power to the servo motor 17 is cut off, the servo motor 17 stops, and the variable rings 129, 13
The 0 position is maintained, and the compressor capacity is set according to the cooling load.

On the other hand, due to a decrease in the cooling load (a decrease in the evaporator suction air temperature, etc.), the air temperature immediately after the evaporator 5 decreases, and the thermistor resistance value R ₁₄ of the sensor 14 increases.
Rs is the resistance value of setting resistor 15 R ₁₅ and variable resistor 163
When the resistance value R becomes larger than the sum of ₁₆₃ , that is,
When Rs>R ₁₅ +R ₁₆₃ , the output 161a of the first comparator 161 goes from a "Lo" level to a "Hi" level, turning on the transistor 164a and turning off the transistor 164b.
66, 167, 171 are turned on.

As a result, the servo motor 17 has the emitter and collector of the transistor 171, and the transistor 1.
A current flows in the opposite direction to the above through the collector emitter 67, causing the servo motor 17 to rotate in the opposite direction, and through the worm gear 18 to the worm gear 1.
25. The operating shaft 126, the spur gears 127, 128, and the variable rings 129, 130 rotate counterclockwise in FIG. 7, and the rotation angle of the variable ring in FIG. 10 decreases, so the compressor capacity decreases. As a result, the air temperature immediately after the evaporator 5 rises and the resistance value of the sensor 14 increases.
_R14 decreases.

At this time, the position detection device 24 is also activated and its resistance value R ₂₄ decreases, and as a result, Rs becomes (R ₁₅
+R ₁₆₃ ) - Rc, that is, Rs < (R ₁₅
+R ₁₆₃ ) -Rc, the output 161a of the first comparator 161 becomes "Lo" level and the transistor 164a turns off, so the transistor 164
b turns on, transistors 166, 167, 17
1 is turned off, the servo motor 17 stops again, and the positions of the 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,
Prevents 130 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, the driving conditions of the automobile become a disturbance factor for evaporator temperature control.

However, since there is a correlation between the refrigerant temperature in the evaporator and the fluctuation in the refrigerant flow rate due to the fluctuation in the compressor rotation speed, the fluctuation in the condenser capacity, etc., this example focuses on this point and calculates the refrigerant temperature in the evaporator. By sensing with the sensor 23 and inputting 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. , 130 need not be moved frequently, and the temperature of the evaporator can be smoothly controlled.

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 (in the characteristic diagram of FIG. 4, the resistance value range of R ₁₆₃ ), the power to the servo motor 17 is cut off and the variable ring 12
9,130 is maintained, and the compressor 12 continues to operate at a predetermined capacity.

Further, when controlling the air temperature immediately after the evaporator to prevent frosting of the evaporator 5, the compressor capacity may be controlled 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 avoid severe 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.
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 the deterioration of durability and the deterioration of running feeling as described in No. 2. Moreover, 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 power savings as a whole.

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.

Further, the present invention includes a timer circuit 25,
When connecting the electromagnetic clutch 13, the compressor 12
The discharge capacity is always minimized, and after the electromagnetic clutch 13 is engaged, the discharge capacity is always maximized. This point will be explained below.

(1) When turning on the start switch 20 with the air conditioning switch 21 open to start the engine 30, in this case, with the air conditioning switch 21 open, no current flows through the coil 19b, and therefore the contact 19a
is open and the electromagnetic clutch 13 is disengaged.
Therefore, the compressor 12 is not applied as a load when starting the engine, and the startability of the engine 30 is not impaired in any way.

Moreover, when the start switch 20 is turned on, the predetermined time t until the charging voltage of the capacitor 250 becomes equal to or higher than the reference voltage _V3 is the output 2 of the comparator 251.
51a is at the "Lo" level, and the transistor 252 is turned off, but since the air conditioning switch 21 is in an open state, no power is supplied to the collector side of the transistor 52, and the transistors 165, 164a, and 164b are turned off. Remains off. Therefore, transistor 16
Since transistors 8, 169, and 170 also remain off, transistors 166, 167, and 171 are turned on. During the predetermined time t until the comparator 251 reverses, the servo motor 17 rotates the variable ring 1.
The time is set to be equal to or slightly longer than the time required to rotate 32a. Therefore, the emitter of the transistor 171 is connected to the servo motor 17.
Since current flows through the collector and the collector-emitter of the transistor 167, the servo motor 17 rotates in the opposite direction, and the variable ring rotation angle of FIG. 10 is sufficiently reduced to ensure that the compressor capacity is at its minimum capacity. In this case, the comparator 161,
Since the servo motor 17 rotates in reverse regardless of the output of the compressor 162, the compressor capacity is always set to the minimum capacity (1/3Vmax). Therefore, even if the air conditioning switch 21 is subsequently turned on, the starting load on the compressor 12 is small, and the running feeling of the vehicle will not be significantly deteriorated.

(2) When the start switch 20 is turned on with the air conditioning switch 21 closed to start the engine 30, in this case, due to the action of the time limit circuit 25, the coil 19b is not energized for the predetermined time t, and the electromagnetic clutch 13 is closed. Since the compressor 12 is turned off, as in the case described above, the compressor 12 is not applied as a load when starting the engine, and the startability of the engine 30 is not impaired.

When the predetermined time t has elapsed, the electromagnetic clutch 13 is engaged, but in this state, the compressor capacity is at the minimum capacity (1/3 Vmax), and a large load is applied to the engine 30 due to the start-up of the compressor 12. Never.

(3) After the electromagnetic clutch 13 is connected As is clear from the above explanation, the electromagnetic clutch 1
3 is connected and the compressor 12 is started, the compressor capacity is always at the minimum. However, if the relay contact 19a closes, current also flows to the comparator 262, and the comparator 26
The output 262a of No. 2 is at "Lo" level. Therefore, transistor 263 is turned off and transistors 164b and 168 are turned on. As a result, the transistor 1 is connected to the servo motor 17.
70 emitter-collector and transistor 1
A current flows through the collector/emitter of 69, and the servo motor 17 rotates in the forward direction to drive the compressor 12.
The net cylinder volume of increases.

Since the rotation of the servo motor 17 in this case is based on the signal from the time limit circuit 25, the compressor 12 will always operate at the maximum capacity for the predetermined time Z until the output 262a of the comparator 262 reverses. . Therefore, in the present invention, the compressor 12 has a minimum capacity at startup, but once it starts operating, the capacity increases to the maximum value, and the cooling sensation at the start of cooling can be greatly improved.

In other words, if the cooling operation is started with the compressor 12 capacity at its minimum, it will take a long time to cool the room to a predetermined temperature, but in the present invention, the cooling operation starts with the compressor 12 capacity at its maximum. This means that the room will be cooled in a relatively short time. In particular, when air conditioning starts, the interior of the vehicle is often extremely hot, such as after parking in the scorching sun, so being able to obtain powerful cold air at the start of air conditioning gives the occupants a comfortable feeling of air conditioning.

and a predetermined time Z (for example, about 5 minutes to 15 minutes)
After the initial cooling of the room is completed, the output 262a of the comparator 262 is reversed to "Hi" level, and as a result, the transistor 263 is turned on.
Transistors 164b and 168 are no longer forced to be turned on. Therefore, at the end of initial cooling, each element 15, 24, 2 according to the cooling state
The compressor capacity will be set according to the signals from 3 and 14.

In the above embodiment, the bypass holes 131a and 131b of the cylinder 107 are connected to the bypass groove 13.
2a, 132b, 133, 134, etc., but this communication 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, the communication destination may be the suction chamber 113, the crank chamber (rotation space 5 of the swash plate 2, or another cylinder 107 in the suction stroke).

Further, in the above embodiment, a swash plate compressor with 10 cylinders is used, but it goes without saying that a swash plate compressor with a plurality of cylinders other than 10 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.

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

The variable capacity member also has a variable ring 129,
The present invention is not limited to 130, and may be modified into various forms depending on the type of compressor, etc. That is, the bypass passage may be opened and closed using a solenoid valve or the like, or when a rotary compressor is used as the compressor 12, the opening position of the bypass hole may be moved. .

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 example, the air temperature immediately after the evaporator was detected as the air side temperature of the evaporator 5, but the evaporator surface temperature may also be detected. Furthermore, the evaporator refrigerant pressure may be detected instead of the evaporator refrigerant temperature.

In addition, if the setting resistor 15 is provided on the control panel of the air conditioner so that the user can manually operate it, and if the user can freely set the resistance value R ₁₅ of the setting resistor 15, it is possible to control the capacity of the compressor to control the room temperature. can be controlled.

Further, in the above example, the control circuit 16 and the time limit circuit 25 were configured using transistors, comparators, etc., and the controller was formed by these two circuits 16 and 25, but a microcomputer was used as the controller. In this case, the control circuit 16
The functions of the time limit circuit 25 and the time limit circuit 25 can be achieved by an integrated circuit configuration.

Further, in the above example, an ignition switch was used as the starting switch 20, but a starter switch may also be used as the switch that is turned on when starting the engine 30, and in the case of a diesel engine, a preheating switch may also be used. May be used.

As described above, in the present invention, when the engine start switch is turned on, the capacity of the compressor is temporarily reduced to a small capacity, and the electromagnetic clutch is not connected until the capacity reaches this small capacity. Therefore, the load on the engine that is applied when starting the engine is reduced, and the starting characteristics of the engine are not impaired in any way. In addition, since the compressor has a small capacity even when the air conditioning switch is turned on while driving after the engine has started, the compressor starting torque applied to the engine is reduced, reducing the deterioration of driving feeling due to shock during driving. It can be prevented. In either case, the frictional torque applied to the electromagnetic clutch is significantly reduced, which has the excellent effect of improving the durability of the electromagnetic clutch.

Furthermore, in the present invention, when the electromagnetic clutch is connected in the small capacity state as described above and the compressor starts operating, the compressor capacity increases to the maximum value immediately. It has the excellent effect of providing a sufficient amount of capacity and providing a comfortable feeling of air conditioning to the passengers.

[Brief explanation of drawings]

Fig. 1 is a refrigeration cycle diagram of a conventionally known automobile air conditioner, Fig. 2 is a block diagram showing the overall control system of the device of the present invention, and Fig. 3 is an electrical diagram illustrating the specific configuration of the controller of the device of the present invention. The circuit diagram, FIG. 4 is an operating characteristic diagram of the comparators 161 and 162 shown in FIG. 3, and FIG. 5 is a sectional view showing one embodiment of the compressor used in the present invention. Indicates the shape along. FIG. 6 is a side view of the compressor. Figure 7 is A of Figure 5.
-A cross-sectional view showing the relationship between the bypass hole and the bypass groove of the variable link. FIG. 8 is a diagram showing the positional relationship of each bypass groove provided in the variable link, and is a sectional view taken along the line B--B in FIG. 9. Figure 9 is a sectional view taken along the line C-C in Figure 8, Figure 10 is a sectional view showing the shape of the bypass groove corresponding to each cylinder, and Figure 11 is the rotation angle of the variable ring and the net cylinder that performs compression work. It is an explanatory view showing the relationship with volume. 5...Evaporator, 8...Blower, 11...Ventilation casing, 12...Compressor, 14, 23...Temperature sensor, 16...Control circuit constituting the controller, 1
7... Servo motor forming a drive device, 20... Start switch, 24... Position detection device, 25... Time limit circuit forming a controller, 30... Automobile engine, 129, 130... Variable capacity member Eggplant variable ring.

Claims (1)

[Scope of Claims] 1. A compressor that receives the driving force of an automobile engine via an electromagnetic clutch, and a variable capacity member built into the compressor that changes the discharge capacity of the compressor from a large capacity to a small capacity. , a drive device for driving the variable capacity member; a first detection means for detecting the turning operation of the starting switch of the automobile engine; and upon receiving a turning detection signal from the first detection means, the drive device a first control means that operates to control the discharge capacity of the compressor to a small capacity and prevents engagement of the electromagnetic clutch for a predetermined time; and a second control means that detects engagement of the electromagnetic clutch.
and a second control means for operating the drive device for a predetermined period of time to control the discharge capacity of the compressor to a large capacity when receiving a connection detection signal from the second detection means. An automotive refrigeration cycle control device featuring: 2. The first control means receives a sensing signal from a sensor that senses the temperature or refrigerant pressure related to the degree of cooling of the evaporator, and the discharge capacity of the compressor is also controlled by this sensing signal. The refrigeration cycle control device for an automobile according to claim 1, characterized in that the device is configured to 3. The first detection means includes a timer that is activated by detecting the turning operation of the engine starting switch, and is configured to generate the turning detection signal only for a certain period of time from the time when the starting switch is turned on. A refrigeration cycle control device for an automobile according to claim 1, characterized in that: