JP4407240B2 - Control unit for variable capacity compressor for air conditioning - Google Patents

Description

  The present invention relates to a control device for a variable capacity compressor for air conditioning suitable for use in a vehicle air conditioner.

  Conventionally, like the swash plate type (swash type) compressor of patent document 1, the electromagnetic clutch which transmits the power from the engine which is a drive source to a compressor so that interruption is possible is provided, and the power transmitted via an electromagnetic clutch Are known which perform suction, compression, and discharge of refrigerant. Further, this conventional compressor is provided with a capacity control means for controlling the refrigerant discharge capacity from the compressor, and the operation of the capacity control means is controlled by an electronic control device.

  Incidentally, the electrical connection relationship between the electronic control unit, the electromagnetic clutch, and the capacity control means is not described in Patent Document 1, but is generally connected as shown in FIG. In the conventional example of FIG. 6, the electromagnetic clutch 17 and the electromagnetic control valve 23 are connected to the electronic control unit 24 so as to be electrically in parallel by lead wires 50a and 50b.

According to this, whether the power from the engine 16 is transmitted to the compressor 51 or disconnected by controlling whether the electromagnetic clutch 17 is energized or interrupted by the control current I from the electronic control unit 24. Can be controlled. The refrigerant discharge capacity from the compressor 51 is controlled by controlling the opening angle of the electromagnetic control valve 23 by the control current I from the electronic control unit 24 and controlling the inclination angle of the swash plate, that is, the stroke of the piston. be able to.
JP 2003-002048 A

  However, in the conventional compressor 51 of FIG. 6, the power to the compressor 51 may be intermittent in a state where the refrigerant discharge capacity is large (the inclination angle of the swash plate is large). At this time, if the connecting member receiving the power from the engine 16 in the electromagnetic clutch 17 mechanically contacts the connecting surface on the compressor 51 side, the power required for driving the compressor 51 is increased. Suddenly a big force is applied to the surface.

  For this reason, the impact when the connecting member of the electromagnetic clutch 17 and the connecting surface on the compressor 51 side that are mechanically contacted is increased or decreased. As a result, there is a problem that the wear of the contact surface between the connecting member of the electromagnetic clutch 17 and the connecting surface on the compressor 51 side becomes severe. Furthermore, there is a problem that the sound generated at the time of interruption is increased.

  In addition, since the electromagnetic clutch 17 and the electromagnetic control valve 23 are electrically connected in parallel to the electronic control device 24 via the lead wires 50a and 50b, there are a plurality of control systems through which the control current I from the electronic control device 24 flows. There is also the problem of complexity.

  In view of the above points, the present invention provides a control apparatus for a variable displacement compressor that can perform intermittent power transmission from a drive source to a compressor by controlling an electromagnetic clutch, and further control a refrigerant discharge capacity by a capacity control means. An object of the present invention is to reduce the impact generated when the power from the drive source to the compressor is interrupted, and to reduce the wear and mechanical noise of mechanically connected parts.

  Another object of the present invention is to simplify a control system in which a control current flows from an electronic control device to a controlled object.

In order to achieve the above object, according to the first aspect of the present invention, the power of the drive source (16) is supplied to the compressor (11) that is driven by the power from the drive source (16) and sucks, compresses, and discharges the refrigerant. Is provided with electromagnetic clutches (17, 30) that can be intermittently transmitted to the compressor (11), and capacity control means (23) that controls the refrigerant discharge capacity of the compressor (11),
After the refrigerant discharge capacity is made substantially zero by the capacity control means (23), the power from the drive source (16) to the compressor (11) is interrupted by the electromagnetic clutch (17, 30). It features a control device for a variable capacity compressor for air conditioning.

  According to this, the refrigerant discharge capacity is substantially zero by the capacity control means (23), that is, after the power for refrigerant discharge in the compressor becomes substantially zero, the compressor (11) by the electromagnetic clutch (17, 30) is supplied. Can be intermittent. Therefore, since the power load applied to the components that mechanically transmit power from the drive source (16) to the compressor (11) can be reduced, the impact generated when the power is interrupted can be reduced. By reducing the impact, it is possible to reduce the noise generated when the contact surfaces of the parts that mechanically transmit power from the drive source (16) to the compressor (11) are worn and intermittent.

Further, in the invention according to claim 1, being adapted to electrostatic magnetic clutch (17, 30) and capacity control means (23) is controlled by the control current (I) from the electronic control unit (24),
An electromagnetic clutch (17, 30) or an electromagnetic clutch circuit (27b, 27c, 28a) for driving the electromagnetic clutch (17, 30) and a capacity control means (23) are electrically connected in series. It features a control device.

  According to this, the electromagnetic clutch (17, 30) or the electromagnetic clutch circuit (27b, 27c, 28a) for driving the electromagnetic clutch (17, 30) and the capacity control means (23) are electrically connected in series, that is, one control. Since it is connected as a system, as compared with the case where the electromagnetic clutches (17, 30) and the capacity control means (23) are connected in parallel as in the conventional example of FIG. The control system can be reduced and simplified.

It is preferable as defined in claim 1, conductive magnetic clutch (17, 30), when the control current (I) is larger than the first predetermined value (Ic), the drive source in connected state ( 16) is transmitted to the compressor (11). On the other hand, when the control current (I) is not more than the first predetermined value (Ic), the power from the drive source (16) is transferred to the compressor (11). To a disconnected state that does not communicate to
The capacity control means (23) reduces the discharge capacity of the compressor (11) to approximately 0 when the control current (I) is equal to or smaller than a second predetermined value (Ia) that is larger than the first predetermined value (Ic). On the other hand, if the control current (I) is larger than the second predetermined value (Ia) and is smaller than the third predetermined value (Imax), which is larger than the second predetermined value (Ia), the compression is performed. The variable capacity compressor for air conditioning may be controlled by controlling the discharge capacity of the machine (11) to a capacity corresponding to the control current (I).

Further, in the invention described in claim 2 is characterized Oite to claim 1, the control device of the air conditioning compressor using pin clutch (30) as an electromagnetic clutch.

  By the way, in the electromagnetic clutch, the power from the drive source (16) is supplied to the compressor by sucking and mechanically connecting the movable member on the power supply side to the compressor (11) receiving the power by the electromagnetic attraction force. (11). In the electromagnetic clutch that transmits the power from the drive source (16) to the compressor (11), the power is transmitted by the frictional force of the contact surface between the connection member on the power supply side and the connection surface on the compressor (11) side. Is common.

  According to this, the connection member on the electromagnetic clutch side must have a contact surface with a certain area. Therefore, the connecting member that is a movable member is large, that is, becomes heavy. Since the electromagnetic attractive force of the electromagnetic clutch changes in proportion to the magnitude of the current flowing through the exciting coil, a large current is required to attract a large and heavy movable member.

However, in claim 2 , power is supplied from the drive source (16) to the compressor (11) by fitting the pin-type movable member on the side to which power is supplied into the recess on the compressor (11) side that receives power. A transmitting pin clutch (30) is used. Therefore, the pin-type movable member that must be moved by the electromagnetic attractive force is smaller and lighter than the size of the connection member that is a movable member of the above-described general electromagnetic clutch. Therefore, the electromagnetic attraction force for attracting the movable member can be reduced. That is, the current required when the power from the drive source (16) is interrupted can be reduced.

Moreover, since usually performing capacity control by capacity control means (23) after the electromagnetic clutch (17, 30) becomes a connected state, in particular an electromagnetic clutch (17, 30) and the displacement control means as claimed in claim 1 ( 23) are connected in series, the current value used when the electromagnetic clutch (17, 30) is engaged is smaller than the drive current value of the capacity control means (23). For this reason, if the current required for power connection / disconnection from the drive source (16) is reduced using the pin clutch (30) as in claim 4, the clutch connection / disconnection, that is, the power from the drive source (16) is more reliably achieved. Can be intermittent.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
In the present embodiment, the variable capacity compressor according to the present invention is applied to a compressor of a vehicle air conditioner. FIG. 1 is a schematic diagram illustrating a vehicle air conditioner according to the present embodiment. A variable capacity compressor 11 sucks, compresses, and discharges a gas phase refrigerant in a refrigeration cycle of the vehicle air conditioner. Here, the refrigeration cycle of the present embodiment will be described. The high-temperature and high-pressure gas-phase refrigerant discharged from the compressor 11 flows into the radiator 12, where it radiates heat to the outside air, that is, is cooled by the outside air.

  The refrigerant radiated by the radiator 12 is decompressed to a low pressure by the expansion valve 13 (decompression unit), enters a gas-liquid two-phase state, and then flows into the evaporator 14 where it absorbs heat from the conditioned air into the passenger compartment. Evaporate. The evaporated refrigerant flows into the accumulator 15, where it is separated into a gas phase refrigerant and a liquid phase refrigerant. The liquid phase refrigerant is stored in the accumulator 15 as a surplus refrigerant, and the gas phase refrigerant is supplied to the suction side of the compressor 11.

  With such a refrigeration cycle, the refrigerant absorbs heat (cools the conditioned air) from the conditioned air into the passenger compartment by the evaporator 14. A heater (not shown) for heating the conditioned air is disposed downstream of the conditioned air flow of the evaporator 14, and the temperature of the conditioned air is adjusted together with the evaporator 14.

  By the way, as is well known, the compressor 11 is driven by the power of the vehicle running engine 16 being transmitted through the electromagnetic clutch 17, the belt 18 and the like. For example, the compression described in JP-A-2003-002048 is disclosed. This is a swash plate type (swash type) variable capacity compressor 11 that changes the refrigerant discharge capacity by changing the inclination angle of the swash plate.

  As is well known, the electromagnetic clutch 17 of the present embodiment is provided with a rotor 17a that receives power from the engine 16. The rotor 17a is always rotating when the engine 16 is driven. An excitation coil 17b is arranged on the rotor 17a. On the other hand, a rotary shaft 20 is arranged in the compressor 11, a hub 21 is arranged on the rotary shaft 20 so as to rotate integrally with the rotary shaft 20, and a connection member 22 is further arranged on the hub 21. Yes.

  The compressor 11 sucks and compresses refrigerant by reciprocating a piston connected to the swash plate through a shoe by rotating a swash plate inclined with respect to the rotation shaft 20 integrally with the rotation shaft 20. Discharging. The electromagnetic control valve 23 that controls the refrigerant discharge capacity of the compressor 11 by adjusting the inclination angle of the swash plate will be described later.

  Next, drive circuits for the electromagnetic clutch 17 and the electromagnetic control valve 23 shown in FIG. 2 will be described. The electromagnetic control unit (ECU) 24 includes a well-known microcomputer composed of a CPU, ROM, RAM, etc. (not shown) and its peripheral circuits. And the A / C switch 25a which turns ON / OFF the air conditioner (A / C) which is the sensor group 25, the vehicle interior temperature sensor 25b which detects the temperature in the vehicle interior, and the temperature setting means 25c by the user (occupant) Based on the value, arithmetic processing according to a preset program is performed, and the control current I is output to the electromagnetic clutch 17 and the electromagnetic control valve 23. The ECU 24 is driven by power supplied from the storage battery 26.

  The operation of the electromagnetic clutch 17, more specifically, the electromagnetic clutch circuits 27 b, 27 c, 28 a that control the driving of the electromagnetic clutch 17 and the electromagnetic control valve 23 are controlled by a control current I from the ECU 24. The electromagnetic clutch 17, the electromagnetic clutch circuits 27b, 27c, 28a and the electromagnetic control valve 23 are electrically connected in series by lead wires 27a, 27b, 27c through which a control current I from the ECU 24 flows. The electromagnetic clutch circuit includes lead wires 27b and 27c and an exciting coil 28a of the relay 28.

  The relay 28 is switching means that switches between when the current from the storage battery 26 is energized to the exciting coil 17 b of the electromagnetic clutch 17 and when it is interrupted. When the ECU 24 supplies a control current I> Ic to the exciting coil 28a of the relay 28, the relay 28 is turned on. Specifically, when the movable iron piece 28 b is attracted to the exciting coil 28 a, the contact point connected to the movable iron piece 28 b is closed, and the current from the storage battery 26 flows to the electromagnetic clutch 17 via the relay wire 29.

  In addition, when the on / off state of the electromagnetic clutch 17 can be switched only by the control current I from the electronic control unit 24, the electromagnetic clutch circuits 27b, 27c and 28a are eliminated and the electromagnetic control valve 23 and the exciting coil 17b of the electromagnetic clutch 17 are removed. May be electrically connected in series.

  Next, the operation of the electromagnetic clutch 17 and the electromagnetic control valve 23 in the present embodiment will be described based on the control flowchart of the ECU 24 in FIG. 3 and the operation of the electromagnetic clutch 17 and the electromagnetic control valve 23 by the control current I in FIG. To do.

  First, in S110, the ECU 24 determines whether or not the A / C switch 25a is ON. If the A / C switch 25a is ON, the process proceeds to S120. The case where the A / C switch 25a is OFF will be described later.

  In S120, the ECU 24 determines whether or not the in-vehicle temperature is lower than the temperature obtained by subtracting α from the set temperature based on the input values from the vehicle interior temperature sensor 25b and the temperature setting means 25c. Here, α is a correction value that is uniquely determined at the time of shipment of the ECU 24 or is determined each time in consideration of the outside air temperature, the amount of solar radiation, and the like. If the vehicle interior temperature is equal to or higher than the temperature obtained by subtracting α from the set temperature, the process proceeds to S130. The case where the in-vehicle temperature is lower than the set temperature minus α will be described later.

  In S130, the ECU 24 turns on the electromagnetic clutch 17. Specifically, when the electronic control device 24 passes a current of control current I> Ic, the relay 28 described above is turned on, and the current from the storage battery 26 flows to the electromagnetic clutch 17. The electromagnetic clutch 17 is a well-known one, and when it is energized (ON), an electromagnetic attractive force is generated between the connection member 22 and the connection surface 17c of the rotor 17a by the magnetic field induced by the excitation coil 17b to cause the connection member 22 to move. Adsorbed to the connection surface 17c. The connecting member 22 is formed of a ferromagnetic material (S10C in this embodiment) such as an iron-based material having a low carbon content.

  As a result, the power of the engine 16, that is, the power of the rotor 17 a is transmitted to the rotary shaft 20 via the connection member 22 and the hub 21. Note that when the energization of the electromagnetic clutch 17 is cut off (OFF), the connecting member 22 is not in contact with the connecting surface 17c of the rotor 17a so that power is not transmitted. When the electromagnetic clutch 17 is turned on, the control of the ECU 24 proceeds to S140.

  In S <b> 140, the ECU 24 supplies a control current I of Ia <I ≦ Imax to the electromagnetic clutch 17 and the electromagnetic control valve 23. At this time, as shown in FIG. 4, the electromagnetic clutch 17 is turned on (that is, the compressor 11 is turned on), and the electromagnetic control valve 23 has the refrigerant discharge capacity of the compressor 11 corresponding to the control current I. To control the opening degree. Specifically, the refrigerant discharge pressure of the compressor 11 is adjusted by the opening degree of the electromagnetic control valve 23, and this refrigerant is introduced into the swash plate chamber of the compressor 11. At this time, if the refrigerant lowers the pressure in the swash plate chamber, the inclination angle of the swash plate increases and the piston stroke increases, so that the refrigerant discharge capacity of the compressor 11 increases, and conversely when the pressure in the swash plate chamber increases. Since the inclination angle of the swash plate is reduced and the stroke of the piston is reduced, the refrigerant discharge capacity is reduced.

  At this time, when the refrigerant discharge capacity of the compressor 11 is reduced, the amount of heat absorbed by the refrigerant from the conditioned air into the vehicle interior is reduced by the evaporator 14, and when the discharge capacity is increased, the refrigerant is conditioned air into the vehicle interior by the evaporator 14. The amount of heat absorbed from the heat increases. Thus, after ECU24 controls the electromagnetic control valve 23 by the control current I, it returns to S110.

  If the ECU 24 determines in S120 that the in-vehicle temperature is lower than the temperature obtained by subtracting α from the set temperature, the ECU 24 performs S210. In S210, the ECU 24 supplies a control current I of I ≦ Ia (where Ic <I). At this time, as shown in FIG. 4, the electromagnetic clutch 17 is turned on (that is, the compressor is turned on), and the electromagnetic control valve 23 makes the refrigerant discharge capacity of the compressor 11 substantially zero. Thereafter, the control of the ECU 24 proceeds to S220, and the ECU 24 turns off the electromagnetic clutch 17 by supplying a control current I satisfying I ≦ Ic, that is, the compressor in which the power from the engine 16 is not transmitted to the compressor 11 as described above. Turn off (see FIG. 4). Control of ECU24 returns to S110 after the process of S220.

  In S110, when the ECU 24 determines that the A / C switch 25a is OFF, the ECU 24 performs the control of S310 and then S320. In S310 and S320, the ECU 24 controls the electromagnetic control valve 23 by flowing a control current I of I ≦ Ia (where Ic <I) so that the refrigerant discharge capacity of the compressor 11 is substantially zero, as in S210 and S220. . Thereafter, a control current I satisfying I ≦ Ic is supplied to turn off the electromagnetic clutch 17. In S330, the control of the electromagnetic clutch 17 and the electromagnetic control valve 23 by the ECU 24 ends.

  Next, the operation and effect of this embodiment will be described. After the electromagnetic control valve 23 sets the refrigerant discharge capacity of the compressor 11 to be substantially 0 (S210, S310), the power to the compressor 11 by the electromagnetic clutch 17 is interrupted. (S220, S320) Therefore, it is possible to reduce the impact generated when the connection member 22 that mechanically contacts and transmits power and the connection surface 17c of the rotor 17a are intermittent.

  In this embodiment, when the electromagnetic control valve 23 stops the compressor 11 (S220, S320), the refrigerant discharge capacity is substantially zero (S210, S310), and the compressor 11 is driven, that is, the rotating shaft 20 rotates. The necessary power is reduced. That is, since the compressor 11 is controlled so that the electromagnetic clutch 17 is in a disconnected state in which the power is not transmitted after the refrigerant discharge capacity is almost zero (S210, S310), the electromagnetic clutch 17 naturally has power. When the connection state for transmission is reached, the refrigerant discharge capacity is substantially zero.

Therefore, when the electromagnetic clutch 17 is connected, the force applied to the contact surface at the moment when the connection member 22 of the electromagnetic clutch 17 and the connection surface 17c of the rotor 17a come into contact with each other is small, so the connection surface 17c of the connection member 22 and the rotor 17a is intermittently connected. The impact generated sometimes can be reduced.
Thereby, abrasion of the contact surface of the connection member 22 and the connection surface 17c can be prevented. Furthermore, it is possible to reduce the sound generated during the intermittent operation.

  Further, the electromagnetic clutch 17, the electronic clutch circuits 27b, 27c, 28a for driving the electromagnetic clutch 17 and the electromagnetic control valve 23 are electrically connected in series by the lead wires 27a, 27b, 27c, so that the control system is 1 As a result, the control system can be simplified.

  In this embodiment, the electromagnetic clutch 17, the electromagnetic clutch circuits 27b, 27c, 28a and the electromagnetic control valve 23 are connected in series by the lead wires 27a, 27b, 27c, so that there is one control system. Therefore, as in the conventional example of FIG. 6, the electromagnetic clutch 17 and the electromagnetic control valve 23 are connected in parallel to the electronic control device 24 by the lead wires 50a and 50b, and the control system is simplified compared to the case where two control systems are required. Can be.

  In this embodiment, as shown in FIG. 4, when the control current I from the ECU 24 is Ia <I ≦ Imax, the electromagnetic clutch 17 is in the connected state, and the power from the engine 16 is transmitted to the compressor 11. While driving the compressor 11, the electromagnetic control valve 23 controls the discharge capacity of the compressor 11 to a capacity corresponding to the control current I. Further, when the control current I is I ≦ Ia and Ic <I (where Ic <Ia), the electromagnetic clutch 17 is engaged and the compressor 11 is driven, and the electromagnetic control valve 23 is discharged from the compressor 11. The capacity is controlled to approximately zero. Further, when the magnitude of the control current I is I ≦ Ic (where Ic <Ia), the electromagnetic clutch 17 is controlled to be disconnected so that the power from the engine 16 is not transmitted to the compressor 11.

  By such control of the control current I, the ECU 24 realizes the operation control of the electromagnetic clutch 17 and the electromagnetic control valve 23 electrically connected in series by the lead wires 27a, 27b, and 27c, that is, by one control system. .

(Second Embodiment)
In the first embodiment, as the electromagnetic clutch 17 that transmits power from the engine 16, an electromagnetic attractive force is generated between the connection member 22 and the connection surface 17c of the rotor 17a by the magnetic field induced by the excitation coil 17b, and the connection is made. The member 22 used was in contact with the connection surface 17c of the rotor 17a.

  However, in this embodiment, the power from the engine 16 is transmitted to the rotating shaft 20 of the compressor 11 using a pin clutch 30 as shown in FIG. In this pin clutch 30, the pin-shaped pin-type connecting member 31 is attracted (displaced) toward the rotor 17a by a magnetic field excited by energization of the exciting coil 17b. The rotor 17a is provided with a fitting recess 17d in a shape in which the sucked pin-type connecting member 31 is fitted, and the pin-type connecting member 31 is fitted into the fitting recess 17d by electromagnetic attraction force.

  In the first embodiment, the power from the engine 16 is generated by the electromagnetic attraction between the connection member 22 and the connection surface 17c due to the magnetic field and the frictional force between the connection member 22 and the connection surface 17c. It is transmitted from the receiving rotor 17a side (that is, the connecting surface 17c) to the rotating shaft 20 side that rotates together with the hub 21 (that is, the connecting member 22).

  However, in the pin clutch 30, the pin-type connecting member 31 is fitted into the fitting concave portion 17d, whereby the fitting concave portion 17d of the rotor 17a and the hub 21 on which the pin-type connecting member 31 is disposed are connected. Thus, the power is transmitted from the rotor 17a receiving the power of the engine 16 (that is, the fitting recess 17d) to the rotating shaft 20 that rotates integrally with the hub 21 (that is, the pin-type connecting member 31). The configuration is the same as that of the first embodiment except that the pin-type clutch 30 is used.

  Next, the operation and effect of this embodiment will be described. Since the pin-type clutch 30 is used, the current from the storage battery 26 required for intermittent power transmission from the engine 16 can be reduced.

  By the way, in order to transmit power by the frictional force between the connection member 22 and the connection surface 17c of the rotor 17a as in the first embodiment, the connection member 22 must have a certain contact surface area. That is, it has a certain size (= weight). At this time, if the connection member 22 having a large weight is moved by the electromagnetic attractive force, it is necessary to increase the electromagnetic attractive force by increasing the magnetic field to be excited by flowing a larger current through the exciting coil 17b.

  On the other hand, in the pin clutch 30, the pin type connection member 31 and the fitting recess 17d of the rotor 17a are mechanically connected to transmit power, so that the pin type connection member 31 can be made small (light). Therefore, the current flowing through the exciting coil 17b can be reduced.

  Further, when power is transmitted by the pin clutch 30, force is applied to the pin-type connecting member 31 and the fitting recess 17 d in the circumferential direction around the rotation shaft 20. Also in the present embodiment, when the electromagnetic control valve 23 stops the compressor 11 (S220, S320), the refrigerant discharge capacity is substantially zero (S210, S310), and the compressor 11 is driven, that is, the rotating shaft 20 rotates. The necessary power is reduced.

  Accordingly, since the circumferential force applied to the pin-type connecting member 31 and the fitting recess 17d is small, the pin-type connecting member 31 is easily detached from the fitting recess 17d when the power transmission of the pin clutch 30 is interrupted. be able to. As a result, the pin type connection member 31 continues to be fitted into the fitting recess 17d even though the ECU 24 performs control to intermittently transmit power to the pin clutch 30, and the compressor 11 is driven. Can be prevented. Needless to say, in the second embodiment, it is possible to achieve an effect that can simplify the control system of the electronic control unit 24 described in the first embodiment.

(Other embodiments)
In the above-described embodiment, an example of a swash plate type variable displacement compressor has been shown, but the present invention is not limited to this, and the communication state between the discharge side and the suction side is adjusted by the operation by the control current. Any variable capacity system that changes the refrigerant discharge capacity may be used.

  Further, in the above-described embodiment, the present invention is applied to a cooling device that cools the air into the room, but the present invention is not limited to this, and even a heating device that heats the air into the room in a radiator. Good. Moreover, the path | route of a refrigerant | coolant may be switched and a heat radiator and an evaporator may be switched.

  In the above-described embodiment, the present invention is applied to the vehicle air conditioner. However, the present invention is not limited to this, and is also applied to a stationary air conditioner that drives a compressor using a drive source. can do.

  In the above-described embodiment, an example of a contact relay that uses a movable iron piece as a relay to connect and disconnect contacts is shown. However, the present invention is not limited to this, and a storage battery is controlled by a control current from an ECU. As long as the current from can be turned on and off. For example, a non-contact relay using a semiconductor element such as a transistor can be used.

It is a schematic diagram which shows the refrigerating cycle of the vehicle air conditioner which concerns on 1st Embodiment. It is a circuit diagram which shows the drive circuit of the electromagnetic clutch and electromagnetic control valve which concern on 1st Embodiment. It is a control flow chart of the electronic control unit concerning a 1st embodiment. It is the characteristic view which represented the action | operation of the electromagnetic clutch and electromagnetic control valve which concern on 1st Embodiment with the magnitude | size of control current. It is sectional drawing which showed the pin clutch which concerns on 2nd Embodiment, (a) The power disconnection state from a drive source, (b) The power transmission state from a drive source is shown. It is a schematic diagram which shows the general electric control circuit in the compressor of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Compressor, 16 ... Vehicle engine (drive source), 17 ... Electromagnetic clutch,
23 ... Electromagnetic control valve (capacity control means), 24 ... ECU (electronic control unit),
27b, 27c ... lead wire (electromagnetic clutch circuit),
28a ... excitation coil (electromagnetic clutch circuit), 30 ... pin clutch (electromagnetic clutch).

Claims (2)

An electromagnetic clutch (11) that is driven by the power from the drive source (16) and transmits the power of the drive source (16) to the compressor (11) in an intermittent manner to the compressor (11) that sucks, compresses and discharges the refrigerant. 17 and 30) and capacity control means (23) for controlling the refrigerant discharge capacity of the compressor (11),
After the discharge capacity of the refrigerant is made substantially zero by the capacity control means (23), the power from the drive source (16) to the compressor (11) is interrupted by the electromagnetic clutch (17, 30). has become way,
The electromagnetic clutch (17, 30) and the capacity control means (23) are controlled by a control current (I) from an electronic control unit (24),
The electromagnetic clutch (17, 30) or the electromagnetic clutch circuit (27b, 27c, 28a) for driving the electromagnetic clutch (17, 30) and the capacity control means (23) are electrically connected in series,
The electromagnetic clutch (17, 30) is a connection for transmitting power from the drive source (16) to the compressor (11) when the control current (I) is larger than a first predetermined value (Ic). State
On the other hand, when the control current (I) is less than or equal to the first predetermined value (Ic), the electromagnetic clutch (17, 30) sends power from the drive source (16) to the compressor (11). It becomes a disconnected state that does not transmit,
The capacity control means (23) is configured to discharge the compressor (11) when the control current (I) is equal to or less than a second predetermined value (Ia) that is larger than the first predetermined value (Ic). The capacity is controlled to approximately zero,
On the other hand, when the control current (I) is larger than the second predetermined value (Ia) and not larger than a third predetermined value (Imax) that is larger than the second predetermined value (Ia), the capacitance The control means (23) controls the discharge capacity of the compressor (11) to a capacity corresponding to the control current (I) . The control device for a variable capacity compressor for air conditioning according to claim 1 , wherein the electromagnetic clutch is a pin clutch (30).

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