JPH05164045A - Variable capacity type compressor - Google Patents

Abstract

PURPOSE:To prevent engine stop and excessive energy consumption of an engine by precisely detecting actual rotational torque working on a compressor and precisely adjusting output of the engine to the necessary minimum. CONSTITUTION:Magnetic films 32, 33 are wound around a rotation axis 12 of a compressor, and primary coils 35, 36 on which voltage is applied by a voltage application circuit 37 facing these magnetic films 32, 33 are provided on the fixed side of the compressor. Additionally, on a position apart from the primary coils 35, 36, secondary coils 38, 39 to detect output voltage changing by magnetic distorsion generated on the magnetic films 32, 33 by torque variation of the rotation axis 12 at the time of compression motion are arranged. An oscillator 40 is connected to these secondary coils 38, 39, and a frequency signal from this oscillator is output to an engine output control circuit 43.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement compressor.

[0002]

2. Description of the Related Art As a conventional variable displacement compressor, an oscillating swash plate type variable displacement compressor disclosed in Japanese Utility Model Laid-Open No. 2-240815 has been proposed. This compressor has a crank chamber,
A suction chamber, a discharge chamber, and a cylinder bore that connects these chambers are defined, and a lug plate is supported on the rotary shaft in a housing that accommodates a piston in the cylinder bore so that the piston can reciprocate linearly, and the lug plate can be synchronously rotated. A swing swash plate, which is connected to the lug plate via a hinge mechanism so as to be tiltable in the front-rear direction, slidably supported on a rotation shaft, and is interposed between the swing swash plate and a piston. Through the piston rod, the rotational movement of the swash plate that accompanies the rotation of the lug plate is converted into the reciprocating linear movement of the piston, and oscillates based on the differential pressure between the pressure in the crank chamber and the suction pressure through the piston. The discharge volume is variably controlled by controlling the tilt angle of the swash plate.

Further, as a stroke detecting means for detecting a stroke of a piston proportional to a discharge capacity, an intermediate portion is supported by a casing via a support shaft having an axis line orthogonal to an axis line of a rotary shaft, and one end is for control. An interlocking member connected to the piston and a position detector provided in the casing for detecting the other end position of the interlocking member are provided.
Then, the output signal from the position detector is input to the output control circuit of the engine, and the output of the engine is adjusted according to the capacity of the compressor.

[0004]

In the above conventional variable displacement compressor, since the inclination angle of the swash plate can be detected by the stroke detecting means, the discharge capacity of the compressor can be accurately detected. it can. However, in reality, the power consumed by the compressor is more than doubled depending on the suction pressure and the discharge pressure conditions at the same capacity, especially at 100% capacity, and the original purpose, that is, the output on the engine side is compressed. There was a problem that the output on the engine side could not be improved by the amount of actual power consumed by the machine.

When the actual required torque is large due to the usage conditions of the compressor, an engine stop occurs, and in order to prevent the engine stop from occurring, the engine is always compressed at a high output (rotation speed) higher than a predetermined value. Since the machine is driven, there is a problem that energy consumption increases.

An object of the present invention is to detect the actual torque acting on the compressor by directly detecting the torque acting on the rotary shaft of the compressor, and therefore to optimize the output of the engine. Can be adjusted to the output,
An object of the present invention is to provide a variable displacement compressor that can eliminate engine stop and save energy consumption.

[0007]

In order to achieve the above object, the present invention supports a rotary shaft in a housing, and when the rotary shaft is rotated by an engine, gas suction and compression operations are performed and discharge is performed. In the variable displacement compressor having a variable capacity, a means is provided between the rotary shaft and the housing to provide a torque detector for detecting a rotary torque generated on the rotary shaft.

[0008]

According to the present invention, by taking the above means, when the compressor is rotated by the engine, at that time, a rotating torque is generated on the rotating shaft according to the working conditions such as suction pressure or discharge pressure of the compressor. Since the torque that acts on this rotary shaft is detected by the torque detector, the torque required for the compressor can be accurately detected, and as a result, the output control of the engine can be performed appropriately according to this fluctuation. The engine can be stopped and energy consumption can be saved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. A front housing 3 that forms a crank chamber 2 on the front end surface of the cylinder block 1.
Is fixed to the rear end of the cylinder block through a valve plate 4, and a rear housing 7 constituting a suction chamber 5 and a discharge chamber 6 is fixed to the rear end. A plurality of cylinder bores 8 are provided in the cylinder block 1 in parallel with each other, and pistons 9 are reciprocally housed therein. When the piston 9 is reciprocated, the refrigerant gas is sucked into the cylinder bore 8 from the suction chamber 5 through the suction valve mechanism 10 provided in the valve plate 4, and the refrigerant gas compressed by the piston 9 is valve plate. The gas is discharged into the discharge chamber 6 from the discharge valve mechanism 11 provided on the No. 4 unit.

A rotary shaft 12 is inserted into and supported by the cylinder block 1 and the front housing 3 in parallel with the cylinder bore 8, and is rotatably supported by a bearing 13 on the crank chamber 2 side of the rotary shaft 12. The rotary drive body 14 is fitted and fixed, and a thrust bearing 15 is interposed between the rotary drive body 14 and the inner wall surface of the front housing 3.

A sleeve 16 is fitted on the rotary shaft 12 so as to be reciprocally movable in the axial direction, and a boss portion 18 of a rotary rocking swash plate 18 is fitted to the sleeve 16 via a pair of left and right pins 17.
a is connected. Further, a pin 19 is supported on the back side of the swing swash plate 18, and the pin 19 serves as the rotary drive body 1.
4 is engaged with the elongated hole 20a of the supporting body 20 projecting from a part of the supporting member 4 so as to be capable of reciprocating. A swing swash plate 21 is mounted on the outer periphery of the rotary swing swash plate 18 so as to be swingable in the front-rear direction and non-rotatably via a thrust bearing 22. Further, the swing swash plate 21 and the piston 9 are connected via a rod 23. The swing swash plate 21 is a guide rod 24 inserted in the swash plate so as to be slidable in the radial direction.
The rotation preventing member 25 that guides the lower spherical body of the guide rod 24 in the front-rear direction swings back and forth while the rotation is restricted.

The discharge chamber 6 and the crank chamber 2 have a communication passage 26.
The first control valve 27 is interposed in the middle of the communication passage. Further, the crank chamber 2 and the suction chamber 5 are communicated with each other by a communication passage 28, and a second control valve 29 is provided in the middle of the communication passage 28. Then, the control valves 27, 2
The differential pressure between the pressure acting on the front end face of each piston 9 and the pressure inside the crank 2 acting on the piston rear face is adjusted by 9 and the rotary swing swash plate 18 and the swing swash plate 2 are adjusted according to the pressure difference.
The inclination angle of No. 1 is changed so that the discharge capacity can be adjusted.

As shown in FIG. 1, a seal member 30 is fitted between the rotary shaft 12 and the inner peripheral surface of the boss portion 3a formed in the front housing 3. A non-contact type torque detector 31 is attached to the outer side of the seal member 30. Magnetic films 32 and 33 are wound around the outer peripheral surface of the rotating shaft 12, and grooves 34 are formed in these magnetic films at a plurality of positions obliquely and in parallel with each other.

On the other hand, on the inner peripheral surface of the boss portion 3a, a pair of primary coils 35 and 36 are formed facing the magnetic films 32 and 33.
Is attached, and a predetermined voltage is applied to both primary coils 35 and 36 from a voltage application circuit 37.
Further, a pair of secondary coils 38, 39 is attached so as to be located on the opposite side of both the primary coils 35, 36, and an oscillator 40 is connected to both the secondary coils 38, 39.
0 is connected to the engine output control circuit 42 via the amplifier 41. An output control signal is transmitted from the control circuit 42 to the engine 43.

Next, the operation of the variable displacement compressor constructed as described above will be described. Now, when the compressor is rotationally driven by the rotation of the engine 43 via an electromagnetic clutch (not shown), the rotary shaft 12 rotates the rotary drive unit 1.
4, the piston 9 is reciprocated in the bore 8 via the rotary swash plate 18, the swash plate 21, and the rod 23, and the refrigerant sucked from the suction chamber 5 is compressed in the cylinder bore 8 to be discharged into the discharge chamber 6. Is discharged to.

During this compression operation, for example, the temperature in the passenger compartment rises and the swash plate 2 is swung by the control valves 27 and 29.
Increasing the tilt angle of 1 increases the capacity of the compressor.
In addition, depending on the suction pressure and the discharge pressure, the rotary shaft 1 of the compressor
When the torque acting on 2 is increased, magnetostriction is generated in the magnetic films 32 and 33 provided on the rotating shaft 12 in proportion to the torque, and the output changes ΔV1 + ΔV2 of the applied voltages V1 and V2 of the primary coils 35 and 36 are increased by two. Frequency data, which is detected by the next coils 38 and 39 and is proportional to the rotational torque, is output from the oscillator 40 to the engine output control circuit 42. Then, the output of the engine 43 is adjusted by the control circuit 42 according to the actual rotational torque of the compressor, the engine stop is prevented, and the power consumption is saved.

The present invention is not limited to the above embodiment, and for example, as a structure for detecting the torque acting on the rotary shaft 12, a contact type strain gauge (not shown) is provided on the rotary shaft 12. It is also possible to arbitrarily embody the configuration of each part without departing from the gist of the present invention, such as detecting rotational torque or embodying a variable displacement compressor other than the swash plate compressor. it can.

[0018]

As described above in detail, the present invention can accurately detect the actual rotational torque acting on the compressor, and as a result, the output of the engine can be accurately adjusted to the necessary minimum, and the engine output can be accurately adjusted. There is an effect that it is possible to prevent excessive energy consumption of the stop and the engine.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing an essential part of the present invention.

FIG. 2 is an enlarged cross-sectional view showing the vicinity of a torque detector, which is a main part of the present invention.

FIG. 3 is a longitudinal sectional view showing an embodiment in which the present invention is embodied in a swing swash plate type variable displacement compressor.

[Explanation of symbols]

1 cylinder block, 2 crank chambers, 3 front housing, 3a boss portion, 5 suction chambers, 6 discharge chambers,
7 rear housing, 8 cylinder bore, 9 piston,
12 rotary shafts, 14 rotary drive bodies, 18 rotary swing swash plates, 21 swing swash plates, 31 torque detectors, 32, 33
Magnetic film, 34 groove, 35, 36 primary coil, 37
Voltage application circuit, 38, 39 secondary coil, 40 oscillator, 42 engine output control circuit, 43 engine.

Claims (1)

[Claims] 1. A variable displacement compressor configured to support a rotary shaft on a housing, and when the rotary shaft is rotated by an engine, a gas suction and compression operations are performed and a discharge capacity is changeable. A variable displacement compressor having a torque detector for detecting a rotational torque generated on the rotary shaft between the rotary shaft and the housing.