JPH11132165A - Scroll fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll fluid machine which can secure high total adiabatic efficiency and high reliability over wide operation range. SOLUTION: This scroll fluid machine controls fluid pressure in a target control value range, by impressing suction pressure and spring force, or suction pressure, delivery pressure and spring force onto one end of a piston 33 slidingly moving in the axial line direction in a cylinder provided for a fixing scroll 3, and by adding fluid pressure which is impressed onto a part of at least one side of both scroll members and is used to tightly adhere both scroll members to the other end, and by moving the piston 33 by a balance of forces caused by suction pressure and spring force, or suction pressure, delivery pressure and spring force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll fluid machine for handling refrigerant, air and other compressible gas,
In particular, a suction pressure and a spring force, or a suction pressure, a discharge pressure and a spring force are applied to one end of a piston that slides in an axial direction in a cylinder provided in a part of the non-orbiting scroll member, and both ends are applied to the other end. A fluid pressure for bringing the two scroll members applied to at least a part of the scroll member into close contact is applied, and the suction pressure, the spring force, and the force of the fluid pressure are balanced, or the suction pressure, the discharge pressure, and the spring. By moving the piston with the balance of the force due to the force and the fluid pressure, the fluid pressure is made to be within the target control value range, and high total adiabatic efficiency and high reliability over a wide operation range The present invention relates to a scroll fluid machine which is suitable for ensuring the scrollability.

[0002]

2. Description of the Related Art Scroll fluid machines are widely used in various fields as compressors for refrigeration and air conditioning equipment, and are superior to other types of compressors in terms of high efficiency, high reliability, and low noise. Development and research are being actively conducted as fluid machines equipped with.

[0003] One configuration of a scroll fluid machine will be schematically described with reference to FIG. The basic elements of the compression section are three elements of the fixed scroll 29, the orbiting scroll 3, and the frame 46, and the frame 46 is fixed to the closed container 1. The basic components of the fixed scroll 29 include a wrap 29a, an end plate 29b, a lap bottom 29c, a lap tip 29d, and a discharge port 29e. The basic components of the orbiting scroll 3 are a wrap 3a, a head plate 3b, and a lap bottom. 3c and a lap tip 3d.

[0004] The basic elements of a drive unit for orbiting the orbiting scroll 3 are a stator 12, a rotor 13, which is an electric motor,
The crankshaft 11, the Oldham ring 9, which is a main component of the rotation preventing mechanism of the orbiting scroll 3, and the crankshaft support member 1 that rotatably engages the frame 46 with the crankshaft 11.
8 and the support member 1 of the orbiting scroll 3 which movably and rotatably engages the orbiting scroll 3 and the eccentric pin portion 11a of the crankshaft 11 in the thrust direction which is the rotation axis direction.
The Oldham ring 9 is disposed in a space defined by the frame 46 and the fixed scroll 29 together with the orbiting scroll 3.

As a lubrication system, a lubricating oil 10 fixed to the lower portion of the closed vessel 1 is passed through a lubrication pipe 14 fixed to the crankshaft 11 and a lubrication hole provided in the crankshaft 11 to form a compression unit and various supporting parts. To the parts 17, 18.

Here, the operation of the basic elements will be described. The rotor 13 is given a rotational force by a rotating magnetic field generated by the stator 12, and the crankshaft 11 fixed to the rotor 13 performs a rotating operation as the rotor 13 rotates. The orbiting scroll 3 is movably and rotatably engaged with the eccentric pin portion 11a of the crankshaft 11 in the thrust direction.
The rotation of the orbiting scroll 3 is converted into a turning motion by a rotation preventing mechanism. The volume of the compression chamber 4 formed by meshing the fixed scroll 29 and the orbiting scroll 3 decreases as the orbiting scroll 3 orbits.

Next, the compression operation of the scroll fluid machine will be briefly described with reference to FIG. FIG. 13 is a sectional view of the compression chamber 4 formed by meshing the fixed scroll 29 and the orbiting scroll 3. The compression chambers 4a, 4b
FIG. 4 shows a compression chamber in a compression process, and shows a mode of a compression operation in which the volume is reduced by orbiting movement of the orbiting scroll 3. In the compression operation, the working fluid is sucked into the compression chamber 4 via the suction port 5 and the suction space 15 with the turning movement of the orbiting scroll 3. The sucked working fluid is sequentially reduced in volume as in the compression chambers 4a and 4b, and passes through the discharge space 16 and the discharge port 6 when the compression chamber reaches a conductive position with the fixed scroll discharge port 29e. Is discharged.

When the fixed scroll 29 and the orbiting scroll 3 are engaged and orbited, the working fluid leaks between the suction space 15 and the compression chamber 4a, between the compression chambers 4a and 4b, and between the discharge port 29e and the compression chamber 4b. It is necessary to ensure sufficient airtightness that does not occur as much as possible. That is, since a force for separating the fixed scroll 29 and the orbiting scroll 3 is generated by the pressure of the compressed working fluid, in order to execute a proper compression operation, the fixed scroll 29 is overcome by overcoming the aforementioned separation force. Action means for applying a pressing force in a direction in which the orbiting scroll 3 is brought into close contact is required.

There have been proposed many means for applying a pressing force for appropriately pressing both scrolls to execute a compression operation. In the example shown in FIG. 12, since the fixed scroll 29 is fixed to the closed container 1 together with the frame 46, by pressing the orbiting scroll 3 against the fixed scroll 29, the action means of the pressing force can be configured. In the following, the orbiting scroll 3 is moved to the fixed scroll 29 to simplify the description.
The fluid pressure for generating a force for pressing the pressure is called a back pressure, and the pressure space in which the back pressure acts is called a back pressure chamber 8.

The back pressure control valves 170 and 180 shown in FIG.
Is a configuration showing the action means of the pressing force described in JP-A-61-118580, and includes a back pressure chamber 8, a suction space 15,
A passage for separately communicating the back pressure chamber 8 and the discharge space 16 is constituted by a release valve structure, and the back pressure is maintained within a design control range, thereby exerting an effect of appropriately pressing the orbiting scroll 3 against the fixed scroll 29. I do.

The structure of the back pressure control valve 190 shown in FIG. 14 is a structure showing the means for applying the pressing force described in Japanese Patent Laid-Open No. 8-303371, and is used when the back pressure does not reach the design control range. It exerts the effect of increasing the back pressure as far as possible. When the back pressure is insufficient, the control valve is configured to connect the compression chamber side space 19 of the eccentric pin portion 11a and the back pressure chamber 8 with each other.
The orbiting scroll 49 exerts an action of appropriately pressing.

[0012]

The above-mentioned means for exerting the pressing force have several problems in securing high overall adiabatic efficiency and high reliability over a wide operating range.

In the means for applying a pressing force using two independent control valves 170 and 180 described in Japanese Patent Application Laid-Open No. 61-118580 shown in FIG. 12, in the back pressure control, the back pressure is the suction pressure and the constant pressure. When the pressure becomes larger than the sum of the pressures, the pressure reduction control valve 170 reduces the back pressure by conducting the back pressure chamber 8 with the suction space 15
When the back pressure becomes smaller than a value obtained by subtracting a certain pressure from the discharge pressure, a pressure control valve 180 is formed to make the back pressure chamber 8 and the discharge space 16 conductive to increase the back pressure, and Operate to maintain pressure.

The pressure reduction control valve 170 and the pressure increase control valve 180 are
This is a relief valve composed of balls 171 and 181 and springs 172 and 182. These control valves 170 and 180 operate independently, the back pressure is Pb, the suction pressure is Ps, the discharge pressure is Pd, the pressure conversion value of the force acting by the spring 172 used for the pressure reduction control valve 170 is k1, and the pressure is increased. If the pressure conversion value of the force acting by the spring 182 used for the control valve 180 is represented by k2, the pressure reducing control valve 170 operates when the relationship of Pb> Ps + k1 (1) is satisfied, and the pressure increasing control valve 180 operates as Pb <Pd. -K2, Pd> k2 (2) It operates when there is a relationship. In this configuration, if there is no relationship of Ps + k1> Pd-k2 (3), the pressure reduction control valve 170 and the pressure increase control valve 180 operate at the same time, and a blow-by state in which the suction space 15 and the discharge space 16 are conducted occurs. Ventilation prevents proper control of back pressure, and also impedes refueling, which lowers overall adiabatic efficiency and reliability. For example, as operating conditions, suction pressure Ps = 0.331 MPa, discharge pressure Pd = 2.14
1 MPa, design back pressure Pb = 0.886 MPa, back pressure control valve 170 with design back pressure Pb ± 0.098 MPa as control range, 1
80, k1 = 0.353 MPa, k2 = 1.353
MPa. At this time, the discharge pressure Pd needs to be 1.353 MPa or more and 2.337 MPa or less because of the restrictions of Pd <Ps + k1 + k2, Pd> k2 (4). If the discharge pressure is equal to or higher than 2.337 MPa, blow-by occurs, and if the discharge pressure is equal to or lower than 1.353 MPa, the pressure increasing control valve 180 does not function.

With the control valves 170 and 180 of the above design, if the suction pressure Ps = 0.101 MPa, the controllable discharge pressure range is 1.353 MPa to 1.808 MPa, and Ps = 0.788 Mpa.
If it is Pa, the controllable discharge pressure range is 1.353 MPa ~
It can be seen that the control range of the suction pressure and the discharge pressure is limited as a whole. Therefore, the back pressure control valves 170 and 180 cannot control the back pressure over a wide range. Further, when the control valves 170 and 180 are opened and closed, the balls 171 and 181 and the frame 46 repeatedly collide with each other, thereby generating noise from the control valves 170 and 180 and reducing the reliability of the valves due to the collision.

The pressing force acting means described in Japanese Patent Application Laid-Open No. 8-303371 shown in FIG. 14 uses a control valve 190 comprising a plunger 191 and a spring 192. In the back pressure control, a force obtained by subtracting the force acting by the spring 192 from the sum of the force due to the suction pressure acting on the plunger 191 and the force due to the pressure in the compression chamber side space 19 of the eccentric pin portion 11a is applied to the plunger 191 by the back pressure. When the force is larger than the acting force, the back pressure chamber 8 and the compression chamber side space 1 of the eccentric pin portion 11a
Pressure control valve 1 for increasing back pressure by conducting pressure space 9
90 is configured to operate to maintain proper back pressure. The control valve 190 shown in FIG. 14 only exerts the pressure increasing effect, and when the back pressure becomes excessive,
Since the control valve 190 cannot exert the pressure reducing effect, the orbiting scroll 49 is excessively pressed against the fixed scroll 48, which causes a reduction in the total adiabatic efficiency due to an increase in sliding loss and a decrease in reliability due to excessive pressing. Also, the control valve 19
Numeral 0 is affected by the centrifugal force accompanying the orbiting movement of the orbiting scroll 49 because it is provided inside the orbiting scroll end plate 49b. Therefore, the control valve characteristic depends on the motor speed, which is not preferable for control.

The present invention has been made in view of the above-mentioned problems in the scroll fluid machine according to the prior art, and has an object to reduce a fluid pressure called a back pressure for bringing both scroll members into close contact with each other by a target control value. It is an object of the present invention to provide a scroll fluid machine suitable for achieving high total adiabatic efficiency and high reliability over a wide operation range by controlling within a range.

[0018]

In order to achieve the above object, a scroll fluid machine according to the present invention is characterized by what is stated in each claim. In particular, claims 1 and 2 are independent claims. The scroll fluid machine according to the fifth aspect of the present invention has a head plate and a spiral scroll wrap standing on the head plate, and turns without rotating on a plane perpendicular to the axial direction in which the scroll wrap stands. A moving orbiting scroll member, a non-orbiting scroll member having a head plate and a spiral scroll wrap standing upright on the head plate, and movement of at least an in-plane direction perpendicular to the axial direction is substantially restricted, and the orbiting scroll member And a non-orbiting scroll member, and a compression chamber whose volume is reduced by substantially closing between the two scroll members; and both scroll portions by the pressure of fluid in the compression chamber. Means for applying a pressing force in a direction of bringing both scroll members into close contact with each other in opposition to a separating force in a direction of separating the end plate of the two scroll members, a suction path for introducing fluid into the compression chamber, and a suction path for introducing the fluid into the compression chamber. The invention according to claim 1, wherein the scroll fluid machine is provided with a discharge path for leading the fluid pressurized at the outside to the outside, and a driving means for orbiting the orbiting scroll member. Both scroll members that apply suction pressure and spring force to one end of a piston that slides in an axial direction in a cylinder disposed in a part of the scroll member, and that act on at least one part of both scroll members at the other end. By applying a fluid pressure for bringing the fluid into close contact with each other, and moving the piston with the balance of the suction pressure and the spring force and the force of the fluid pressure. The pressure is set within a target control value range. In the invention according to claim 5, suction pressure, discharge pressure and spring force are applied to one end of a piston that slides in the cylinder in the axial direction. To the other end, and apply a fluid pressure for bringing the two scroll members, which have been applied to at least a part of at least one of the two scroll members, into close contact with each other, so that the suction pressure, the discharge pressure, the spring force, and the fluid pressure are used. The fluid pressure is set within a target control value range by moving the piston with a balance of forces.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. Hereinafter, for the sake of simplicity, a fluid pressure for generating a force for pressing the orbiting scroll 3 against the fixed scroll 2 is referred to as a back pressure, and a space in which the back pressure acts is referred to as a back pressure chamber. FIG. 1 shows a scroll fluid machine of a high-pressure closed vessel type, in which a discharge space 16 in which a space constituted by a fixed scroll 2 and a frame 7 is removed from a closed vessel 1.
The high pressure discharge working fluid is discharged from the compression chamber 4.

The basic elements of the compression section are the three elements of the fixed scroll 2, the orbiting scroll 3, and the frame 7, and the frame 7 is fixed to the closed container 1. Fixed scroll 2
Is composed of a lap 2a, a head plate 2b, a lap bottom 2c, a lap tip 2d, and a discharge port 2e.
The basic components of the orbiting scroll 3 include a wrap 3a, a head plate 3b, a lap bottom 3c, and a lap tip 3d.

The basic elements of a driving unit for orbiting the orbiting scroll 3 include a stator 12 as an electric motor, a rotor 13,
The crankshaft 11, the Oldham ring 9, which is a main component of the rotation preventing mechanism of the orbiting scroll 2, the crankshaft support member 18 for rotatably engaging the frame 7 and the crankshaft 11, and the orbiting scroll 3 and the crankshaft 11 A support member 17 of the orbiting scroll 3 is movably and rotatably engaged with the eccentric pin portion 11a in a thrust direction which is a rotation axis direction. The Oldham ring 9 includes the frame 7 and the orbiting scroll 3 together. The fixed scroll 2 is provided in the space defined by the fixed scroll 2.

As a lubrication system, the lubricating oil 10 fixed to the lower part of the closed vessel 1 is passed through an oil supply pipe 14 fixed to the crankshaft 11 and an oil supply hole provided in the crankshaft 11.
It supplies to a compression part and each support part 17,18. The lubrication method shown in FIG. 1 utilizes the pressure difference between the discharge space 16 and the pressure in the compression chamber side space 19 of the eccentric pin portion 11a or the pressure in the back pressure chamber 8, but even if another lubrication means is used. I do not care.

Here, the operation of the basic elements will be described. The rotor 13 is given a rotational force by a rotating magnetic field generated by the stator 12, and the crankshaft 11 fixed to the rotor 13 performs a rotating operation as the rotor 13 rotates. The orbiting scroll 3 is movably and rotatably engaged with the eccentric pin portion 11a of the crankshaft 11 in the thrust direction,
The rotational movement of the crankshaft 11 is converted into a rotational movement of the orbiting scroll 3 by a rotation preventing mechanism of the orbiting scroll such as the Oldham ring 9.

In the compression operation, the working fluid is sucked into the compression chamber 4 via the suction port 5 and the suction space 15 as the orbiting scroll 3 orbits. Since the volume of the compression chamber 4 is reduced by the orbiting movement of the orbiting scroll 3, the sucked working fluid is compressed and fixed to the fixed scroll discharge port 2e.
When the compression chamber reaches the conduction position with the discharge port, the liquid is discharged through the discharge space 16 and the discharge port 6. At this time, the fixed scroll 2 and the orbiting scroll 3 are driven by the pressure of the compressed working fluid.
A force is generated to separate the fixed scroll 2 from the above-mentioned force in order to perform an appropriate compression operation.
And a means for applying a pressing force in the direction of bringing the orbiting scroll 3 into close contact with the orbiting scroll 3 are required.

In the first embodiment, the fixed scroll 2
A control valve shown in FIG. 2 as means for controlling a back pressure which is a fluid pressure for generating a pressing force in a direction in which both scrolls are brought into close contact with each other in order to realize a pressing force acting means for appropriately pressing the orbiting scroll 3. 30 is used.

As shown in FIG. 2, a basic element of the control valve 30 is a cylinder 31 provided in a part of the fixed scroll 2.
, A spring 32, a piston 33, a cap 34, two main communication holes 35 and 36 respectively connecting the suction space 15, the back pressure chamber 8 and the cylinder 31, the discharge space 16, the suction space 15 and the back pressure. Three sub-communication holes 37, 38 and 39 respectively connecting the chamber 8 and the cylinder 31. The piston 33 has a shape in which a part of the contact surface with the cylinder 31 is dug into the center of the piston, and the dug part is called a piston dug portion 40. A piston 33 is disposed in the cylinder 31, one end of the piston in the movable direction is provided with a suction space-cylinder main communication hole 35 and a spring 32, and the other end is also provided with a back pressure chamber-cylinder main communication hole 36. Arrange. Both main communication holes 3
5 and 36 are always in communication with each space, and the cap 34 is disposed so as to close the discharge space 16 side of the cylinder 31.

In FIG. 2, the sub-communication hole 37 between the discharge space and the cylinder and the sub-communication hole 38 between the suction space and the cylinder are closed by the piston 33 at the opening on the cylinder 31 side. Therefore, the back pressure chamber-cylinder sub-communication hole 39 is separately conducted through the piston dug portion 40. The back pressure chamber-cylinder sub-communication hole 39 communicates with a cylinder portion corresponding to the piston dug portion 40, and is always in communication with the piston dug portion 40 even when the piston 33 moves. For this purpose, a back pressure side stopper 41 and a suction pressure side stopper 42 shown in FIG. 2 may be used. The back pressure side stopper 41 also exerts the effect of always applying the back pressure via the back pressure chamber-cylinder main communication hole 36 to the back pressure side end face of the piston 33.

The operation of the control valve 30 will be described with reference to FIG. FIG. 3A shows a case where the back pressure is within the target control value range. The suction pressure Ps and the back pressure Pb are introduced into the cylinder 31 via the main communication holes 35 and 36, and the suction pressure is set. This shows that the balance between the sum of the forces exerted by Ps and the spring 32 and the force exerted by the back pressure Pb is maintained.

FIG. 3B shows that the back pressure Pb has not reached the target control value range and the back pressure is insufficient. This is a state that occurs when the suction pressure Ps is increased, when the heating operation is switched from the defrosting operation to the defrosting operation, or immediately after the motor rotation speed is decreased. At this time, the suction pressure Ps and the spring 3
Since the sum of the forces due to 2 becomes greater than the force due to the back pressure Pb, the piston 33 moves to the main communication hole 36 between the back pressure chamber and the cylinder. Due to the movement of the piston 33, the discharge space-cylinder sub-communication hole 37 is electrically connected to the piston dug portion 40, and further, the back pressure chamber-cylinder sub-communication hole 39 is always electrically connected to the piston dug portion 40. Therefore, the discharge space 16 and the back pressure chamber 8 are conducted through the piston dug portion 40. Accordingly, the high discharge pressure flows into the back pressure chamber 8 and increases the back pressure Pb lower than the target control value range. Eventually, when the back pressure Pb is increased to the target control value range, the piston 33 moves to the suction space-cylinder main communication hole 35 side to close the cylinder side opening of the discharge space-cylinder sub communication hole 37, The control is completed by terminating the flow of the high-pressure working fluid into the back pressure chamber 8, and returns to the balanced state as shown in FIG.

FIG. 3C shows that the back pressure Pb is in an excessive back pressure state exceeding the target control value range.
This is a state that occurs not only when the suction pressure Ps is reduced but also immediately after the motor rotation speed is increased. At this time, since the force due to the back pressure Pb is larger than the force due to the suction pressure Ps and the spring 32, the piston 33 moves toward the main communication hole 35 between the suction space and the cylinder. Due to the movement of the piston 33, the suction space-cylinder sub-communication hole 38 is electrically connected to the piston dug portion 40, and further, the back pressure chamber-cylinder sub-communication hole 3 is formed.
9 and the piston dug portion 40 are always in conduction, so that the suction space 15 and the back pressure chamber 8 are conducted through the piston dug portion. Therefore, the back pressure higher than the target control value range is released to the suction space 15 so that the back pressure Pb
Reduce the pressure. Eventually, when the back pressure Pb is reduced to the target control value range, the piston 33 moves to the back pressure chamber-cylinder main communication hole 36 side, and the suction space-cylinder sub communication hole 38.
And the control is completed by stopping the back pressure Pb from flowing into the suction space 15 to return to the equilibrium state as shown in FIG.

By the above operation, the back pressure is Pb, the suction pressure is Ps, the pressure converted value of the force applied by the spring 32 is k, and in particular, the pressure is applied by the spring 32 when the discharge space-cylinder sub-communication hole 37 starts to open. Assuming that the pressure conversion value of the force to be applied is k1 and the pressure conversion value of the force applied by the spring 32 when the suction space-cylinder sub-communication hole 38 starts to open is k2, the control valve 30 calculates Pb = Ps + k (5) ) Can reliably control the back pressure Pb within the target control value range of k1 ≦ k ≦ k2 (6). Further, since the control valve 30 is disposed on the fixed scroll 2, there is no influence of the motor rotation speed. Although FIG. 1 shows only one control valve 30, a configuration in which a plurality of control valves 30 are provided may be used. As described above, the control valve 30 adapts to a wide operating range without being affected by the motor speed, and enables reliable back pressure control.

FIG. 4 shows a second embodiment of the present invention.
This will be described with reference to FIG. FIG. 4 shows a configuration of a control valve 50 which is a means for controlling a back pressure which is a fluid pressure for generating a pressing force in a direction of bringing both scrolls into close contact with each other. Control valve 50
Is the same as the control valve 30 in the first embodiment in that the function of pressing the orbiting scroll 3 against the fixed scroll 63 is exerted.

The basic elements of the control valve 50 shown in FIG. 4 include a cylinder 51 and a spring 5
2, the piston 53, the cap 54, the suction space 15
And two main communication holes 55 and 56 connecting the back pressure chamber 8 and the cylinder 51, respectively, and two sub communication holes 58 and 59.
And The piston 53 has a shape in which a part of the contact surface with the cylinder 51 is dug into the center of the piston, and the dug part is called a piston dug portion 60. A piston 53 is provided in the cylinder 51, a suction space-cylinder main communication hole 55 and a spring 52 are provided at one end in the piston movable direction, and a back pressure chamber-cylinder main communication hole 56 is provided at the other end. The main communication holes 55 and 56 are always connected to the respective spaces, and the cap 54 is disposed so as to close the discharge space 16 side of the cylinder 51.

In FIG. 4, the suction space-cylinder sub-communication hole 58 is closed at the opening on the cylinder 51 side by the piston 53. It is electrically connected to the back pressure chamber-cylinder sub communication hole 59. The back pressure chamber-cylinder sub-communication hole 59 is
It communicates with the cylinder portion corresponding to the piston digging portion 60, so that the piston digging portion 60
This is a configuration that conducts with. For this purpose, a back pressure side stopper 61 and a suction pressure side stopper 62 shown in FIG. 4 may be used.
The back pressure side stopper 61 is provided in the main communication hole 5 between the back pressure chamber and the cylinder.
The effect that the back pressure passing through 6 always acts on the back pressure side end face of the piston 53 is also exerted.

The operation of the control valve 50 will be described. Back pressure is P
b, the suction pressure is Ps, the pressure converted value of the force applied by the spring 52 is k, and the pressure converted value of the force applied by the spring 52 when the suction space-cylinder sub-communication hole 58 starts opening is k2. . Except for having no function of increasing the back pressure Pb, the detailed operation of the control valve 50 is the same as that of the control valve 30 in FIG.
This is the same as Expression (5), which is the control law in the first embodiment, and the target control value range is k ≦ k2 (7). Therefore, the control valve 50 can reliably control the back pressure Pb to be within the target control value range shown in Expression (7).
Further, since the control valve 50 is disposed on a part of the fixed scroll 63, it is not affected by the motor speed.

The arrangement of the control valve 50 on the scroll fluid machine is not limited to one, and a plurality of control valves may be provided. Note that, unlike the control valve 30 according to the first embodiment, the control valve 50 does not have a function of increasing the pressure using the discharge pressure Pd when the back pressure Pb is insufficient. But,
As shown in FIG. 1, when the back pressure chamber 8 also serves as a path for the lubricating oil 10 to be supplied via the support member 17 of the orbiting scroll, the back pressure increases with the supply of the lubricating oil 10 during most of the operation. Receive. Therefore, even with a control valve structure having only a pressure reducing function like the control valve 50, the back pressure can be sufficiently controlled. As described above, the control valve 50 can be applied to a wide operating range without being affected by the motor speed, and can reliably control the back pressure.

However, depending on the operation specifications at the time of startup and the operation specifications accompanied by a sudden increase in suction pressure and discharge pressure, etc.,
There is a possibility that the back pressure is insufficient and the control valve 50 alone cannot cope. Therefore, the fixed scroll 63
Even if the orbiting scroll 3 is disengaged, the compression operation can be executed to some extent by reducing the gap between the fixed scroll 63 and the orbiting scroll 3 at the time of non-driving. According to this, it is possible to reliably increase the back pressure by generating a refueling differential pressure. Second
In this embodiment, the gap between the fixed scroll tooth tip 63c and the orbiting scroll tooth bottom 3c and the gap between the fixed scroll tooth tip 63d and the orbiting scroll tooth bottom 3c are controlled to 15 μm or less. As described above, the use of the scroll fluid machine in which the gap between the tooth roots of the two scrolls is reduced makes it possible to adapt to a wide operating range without being affected by the motor speed and to more reliably control the back pressure. Becomes possible.

FIG. 5 shows a third embodiment of the present invention.
This will be described with reference to FIG. FIG. 5 shows a configuration of a control valve 70 which is a means for controlling a back pressure which is a fluid pressure for generating a pressing force in a direction of bringing both scrolls into close contact with each other. Control valve 70
Is the same as the control valves 30 and 50 in the first and second embodiments in that the function of pressing the orbiting scroll 3 against the fixed scroll 86 is exhibited.

The basic elements of the control valve 70 shown in FIG. 5 are a cylinder 71, a spring 72, a piston 73, a cap 74, a suction space 1
5, three main communication holes 75, 76 and 77 connecting the back pressure chamber 8 and the discharge space 16 to the cylinder 71, and three sub communication holes 79, 80 and 78, respectively. Piston 73
Has a shape in which a part of the contact surface with the cylinder 71 is dug into the center of the piston, and the dug part is formed by the piston dug portion 81
Call. At one end of the cylinder 71 and the piston 73 in the movable direction of the piston, a suction pressure action space 82 and a discharge pressure action space 83 are formed, and when the piston 73 moves, the suction pressure action space 82 and the discharge space act. The pressure working space 83 is not electrically connected.

A piston 73 is provided in the cylinder 71, and a discharge hole-cylinder main communication hole 77 is provided at one end in the piston moving direction.
And a main communication hole 75 between the suction space and the cylinder and a spring 72, and a main communication hole 76 between the back pressure chamber and the cylinder at the other end. In FIG. 5, the spring 72 is provided in the suction pressure working space 82, but may be provided in one or both of the suction pressure working space 82 and the discharge pressure working space 83. . The main communication holes 75, 76, and 77 are always in conduction with the respective spaces, and the cap 74 is disposed so as to close the discharge space 16 side of the cylinder 71.

In FIG. 5, the discharge space-cylinder sub-communication hole 78 and the suction space-cylinder sub-communication hole 79 are closed by the piston 73 on the cylinder 71 side. Accordingly, the back pressure chamber-cylinder sub-communication hole 80 is separately conducted through the piston dug portion 81. The back pressure chamber-cylinder sub-communication hole 80 communicates with a cylinder portion corresponding to the piston dug portion 81, and is always in communication with the piston dug portion 81 even when the piston 73 moves. For this purpose, a back pressure side stopper 84 and a suction pressure side stopper 85 shown in FIG. 5 may be used. The back pressure side stopper 84 also exerts an effect that the back pressure via the back pressure chamber-cylinder main communication hole 76 always acts on the back pressure side end face of the piston 73.

The operation of the control valve 70 shown in FIG. 5 will be described.
The detailed operation of the control valve 70 is the same as that shown in FIG.
This is the same as the control valve 30 of the first embodiment shown in FIG. Therefore, assuming that the back pressure is Pb, the suction pressure is Ps, the discharge pressure is Pd, and the pressure conversion value of the force acting by the spring 72 is k, the control valve 70 calculates Pb = x × Ps + (1-x) × Pd + k. According to the control law of (8), the back pressure Pb can be reliably controlled within the target control value range shown in Expression (6). Where x
Is the ratio of the pressure receiving area of the piston 73 corresponding to the working space 82 of the suction pressure to the sum of the pressure receiving area of the piston 73 corresponding to the working space 82 of the suction pressure and the pressure receiving area of the piston 73 corresponding to the working space 83 of the discharge pressure. And is a positive number from 0 to 1. Further, since the control valve 70 is provided in a part of the fixed scroll 86, it is not affected by the motor speed.

The arrangement of the control valve 70 in the scroll fluid machine is not limited to one, and a plurality of control valves may be provided. As described above, the control valve 70 is adaptable to a wide operating range without being affected by the motor speed, and enables reliable back pressure control. In particular, when the back pressure control value related to only the suction pressure shown in Expression 5 in the first embodiment is not sufficient, the equation (8) is used in the third embodiment.
The back pressure control value related to the suction pressure and the discharge pressure shown in (1) enables more appropriate and reliable back pressure control.

FIG. 6 shows a fourth embodiment of the present invention.
This will be described with reference to FIG. FIG. 6 shows a configuration of a control valve 90 which is a means for controlling a back pressure which is a fluid pressure for generating a pressing force in a direction of bringing both scrolls into close contact with each other. Control valve 90
Has the same operation as the control valve 70 in the third embodiment, except that the pressure receiving positions of the suction pressure working space 102 and the discharge pressure working space 103 on the end face of the piston 93 are reversed. It is easier to manufacture than the third embodiment and can be manufactured at low cost.

FIG. 7 shows a fifth embodiment of the present invention.
This will be described with reference to FIG. FIG. 7 shows a configuration of a control valve 110 which is a means for controlling a back pressure which is a fluid pressure for generating a pressing force in a direction of bringing both scrolls into close contact with each other. Control valve 1
Reference numeral 10 is the same as the control valves 30, 50, 70, and 90 in the first to fourth embodiments in that an effect of pressing the orbiting scroll 3 against the fixed scroll 125 is exhibited.

The basic elements of the control valve 110 shown in FIG.
, Spring 112, piston 113, cap 114
And three main communication holes 115, 11 respectively connecting the suction space 15, the back pressure chamber 8, the discharge space 16 and the cylinder 111.
6 and 117, and two auxiliary communication holes 118 and 11 connecting the suction space 15 and the back pressure chamber 8 to the cylinder 111, respectively.
Nine. The piston 113 has a shape in which a part of the contact surface with the cylinder 111 is dug into the center of the piston, and the dug part is called a piston dug part 120. At one end of the cylinder 111 and the piston 113 in the movable direction of the piston, a suction pressure action space 121 and a discharge pressure action space 122 are formed, and when the piston 113 moves, the suction pressure action space 121 and the discharge space act. The configuration is such that the pressure action space 122 does not conduct.

A piston 113 is provided in the cylinder 111, and a discharge space-cylinder main communication hole 117, a suction space-cylinder main communication hole 115, and a spring 1 are provided at one end in the piston movable direction.
12 and a main communication hole 116 between the back pressure chamber and the cylinder at the other end. In FIG. 7, the spring 112 is disposed in the suction pressure working space 121.
Alternatively, it may be arranged in one or both of the working spaces 122 of the discharge pressure. Each main communication hole 115,
116 and 117 are always in communication with the respective spaces, and the cap 114 is disposed so as to close the discharge space 16 side of the cylinder 111. In FIG. 7, the suction space-cylinder sub-communication hole 118 is closed at the opening on the cylinder 111 side by the piston 113. -Conduction with the inter-cylinder auxiliary communication hole 119. The back pressure chamber-cylinder sub-communication hole 119 communicates with the cylinder portion corresponding to the piston digging portion 120, and is always in communication with the piston digging portion 120 even when the piston 113 moves. For this purpose, a back pressure side stopper 123 and a suction pressure side stopper 124 shown in FIG. 7 may be used. The back pressure side stopper 123 also exerts the effect of always applying the back pressure via the back pressure chamber-cylinder main communication hole 116 to the back pressure side end face of the piston 113.

The operation of the control valve 110 shown in FIG. 7 will be described. Except for having no function of increasing the back pressure Pb, the detailed operation of the control valve 110 is the same as that of the control valve 70 in FIG. 5. The back pressure can be reliably controlled according to the target control value range shown in the second embodiment, which is based on the control rule shown in FIG. Here, the definition of x is the same as in the third and fourth embodiments, the back pressure is Pb, the suction pressure is Ps, the discharge pressure is Pd, the pressure conversion value of the force acting by the spring 112 is k, and particularly the suction pressure is k. The pressure converted value of the force applied by the spring 112 when the space-cylinder sub-communication hole 118 starts to open is represented as k2. Further, since the control valve 110 is provided in a part of the fixed scroll 125, it is not affected by the motor speed.

The arrangement of the control valve 110 in the scroll fluid machine is not limited to one, and a plurality of control valves may be provided. The control valve 110 is different from the control valves 30, 70, and 90 according to the first, third, and fourth embodiments, and is similar to the control valve 50 according to the second embodiment when the back pressure Pb is insufficient. It does not have the function of increasing the pressure using the discharge pressure Pd. Therefore, the effect of not having the boosting function is the same as in the second embodiment.

As described above, the control valve 110 can adapt to a wide operating range without being affected by the motor rotation speed, and can surely control the back pressure. If a scroll fluid machine having a bottom-to-bottom gap is used, the back pressure can be more reliably controlled.

FIG. 8 shows the sixth embodiment of the present invention.
This will be described with reference to FIG. FIG. 8 shows a configuration of a control valve 130 which is a means for controlling a back pressure which is a fluid pressure for generating a pressing force in a direction of bringing both scrolls into close contact with each other. Control valve 1
30 is the same as the control valves 30, 50, 70, 90, 110 in the first to fifth embodiments in that the function of pressing the orbiting scroll 3 against the fixed scroll 140 is exerted.

The basic elements of the control valve 130 shown in FIG.
, Spring 132, piston 133, cap 134
Main communication holes 135 and 136 respectively connecting the suction space 15 and the back pressure chamber 8 to the cylinder 131;
And a main communication hole 137 that communicates with the end face of the piston 133 on the discharge space side. Cylinder 131 and piston 133
The working space 1 of the suction pressure is
38 and the working space 139 of the discharge pressure, and the structure is such that even if the piston 133 moves, the working space 138 of the suction pressure and the working space 139 of the discharge pressure do not conduct.

A piston 133 is provided in the cylinder 131, a discharge space main communication hole 137, a suction space-cylinder main communication hole 135 and a spring 132 are provided at one end in the piston movable direction, and a back pressure chamber-cylinder is provided at the other end. The main communication hole 136 is provided. In FIG. 8, the spring 132 is connected to the working space 13 of the suction pressure.
8, it may be arranged in one or both of the suction pressure working space 138 and the discharge pressure working space 139. In addition, when disposing in the working space 139 of the discharge pressure, a stopper is separately provided.
The cap 134 constitutes the working space 139 of the discharge pressure inside, but the piston 133 moves the working space 139 of the discharge pressure.
Is always closed off and is separated from the suction pressure working space 138.

The operation of the control valve 130 shown in FIG. 8 is not the control structure using the contact surface between the piston 133 and the cylinder 131, but is the same as that of the fifth embodiment.
The sixth embodiment is easier to manufacture than the fifth embodiment and can be manufactured at low cost.

FIG. 9 shows a seventh embodiment of the present invention.
This will be described with reference to FIG. FIG. 9 shows a configuration of a control valve 200 which is a means for controlling a back pressure which is a fluid pressure for generating a pressing force in a direction of bringing both scrolls into close contact with each other. Control valve 2
00 is the control valve 30, 50, 70, 90, 110, 13 in the first to sixth embodiments in that the effect of pressing the orbiting scroll 3 against the fixed scroll 213 is exhibited.
Same as 0.

The configuration of the control valve 200 shown in FIG. 9 is the same as that of the first embodiment except that a sub-communication hole 208 between the compression chamber and the cylinder is used instead of the sub-communication hole between the suction space and the cylinder. The basic configuration is the same. The basic element of the control valve 200 is a cylinder 2 provided in a part of the fixed scroll 213.
01, spring 202, piston 203, cap 2
04, two main communication holes 205 and 206 respectively connecting the suction space 15 and the back pressure chamber 8 to the cylinder 201, the discharge space 16, the compression chamber 214, the back pressure chamber 8 and the cylinder 20
1 and three sub-communication holes 207, 208 and 209, respectively.

The piston 203 has a shape in which a part of the contact surface with the cylinder 201 is dug into the center of the piston, and the dug part is called a piston dug portion 210. Cylinder 20
1, a suction space-cylinder main communication hole 205 and a spring 202 at one end in the piston movable direction,
At the other end, a main communication hole 206 between the back pressure chamber and the cylinder is provided. The main communication holes 205 and 206 are always connected to the respective spaces, and the cap 204 is disposed so as to close the discharge space 16 side of the cylinder 201. In FIG. 9, the discharge space-cylinder sub-communication hole 207 and the compression chamber-cylinder sub-communication hole 20 are shown.
8, the opening on the cylinder 201 side is closed by the piston 203, but the piston 203 moves to be separately connected to the back pressure chamber-cylinder auxiliary communication hole 209 via the piston digging portion 210. .

The back pressure chamber-cylinder sub-communication hole 209 communicates with the cylinder portion corresponding to the piston digging portion 210, so that the piston digging portion 2 is always provided even if the piston 203 moves.
This is a configuration that is electrically connected to 10. For this purpose, a back pressure side stopper 211 and a suction pressure side stopper 212 shown in FIG. 9 may be used. The back pressure side stopper 211 also exerts the effect of always applying the back pressure via the back pressure chamber-cylinder main communication hole 216 to the back pressure side end face of the piston 203.

The auxiliary communication hole 208 between the compression chamber and the cylinder is configured to communicate with the compression chamber via the communication pipe 215.
A check valve 216 that does not conduct from the compression chamber to the sub-communication hole 208 between the compression chamber and the cylinder is provided on the conduction path. Although the communication pipe 215 is used in the seventh embodiment,
A conductive path may be formed in the fixed scroll 213 as a communication hole.

The operation of the control valve 200 shown in FIG. 9 will be described. The back pressure is Pb, the suction pressure is Ps, the pressure conversion value of the force acting by the spring 202 is k, and in particular, the pressure conversion value of the force acting by the spring 202 when the discharge space-cylinder sub-communication hole 207 starts to open. k1, the pressure conversion value of the force applied by the spring 202 when the compression chamber-cylinder sub-communication hole 208 starts to open is k2. Since the detailed operation of the control valve 200 is the same as that of the control valve 30, the control valve 200
The control law and the target control value range are the same as the control laws shown in the first embodiment, ie, Equations 5 and 6, and the back pressure Pb can be reliably controlled.

Further, since the back pressure is directly discharged to the compression chamber when the back pressure is reduced, unlike the first embodiment in which the relatively high pressure and high temperature back pressure is discharged to the suction space 15, the inside of the suction space 15 In this case, unnecessary increase of the working fluid and heating of the sucked working fluid can be eliminated, and the volume efficiency and the total heat insulation efficiency can be further improved. The compression chamber 21
The pressure in the pressure chamber 4 fluctuates with the turning motion, and if the pressure in the compression chamber is high at the back pressure value to be reduced, a backflow from the compression chamber to the back pressure chamber may occur. Therefore, it is necessary to provide the check valve 216 depending on the operation specifications. As described above, the control valve 200 shown in FIG. 9 adapts to a wide operating range without being affected by the motor speed.
Reliable back pressure control becomes possible.

FIG. 1 shows an eighth embodiment of the present invention.
Description will be made using 0 and 11. The scroll fluid machine of the low-pressure closed container type shown in FIG. 10 has a closed container 27 except for the compression chamber 4 and the like, except that the high-pressure discharge space 16 composed of the closed container 27 and the fixed scroll support member 22 is partially provided.
Most of the inside is configured as a low-pressure suction space 15.
In the eighth embodiment, the high-pressure sealed container type scroll fluid machine described in the first to seventh embodiments is:
The means for applying the pressing force in the direction in which the fixed scroll 25 and the orbiting scroll 3 are hermetically sealed, the oil supply system, and the like are greatly different.

In the eighth embodiment, as the means for applying the pressing force, since the pressure in the closed container 27 is almost low,
Contrary to the first to seventh embodiments, means for pressing the fixed scroll 25 against the orbiting scroll 3 is used. Since the lubricating oil 10 is retained in the low-pressure suction space 15, the oil supply system requires means 24 such as a liquid pump for forcibly circulating the lubricating oil 10.

As the configuration of the eighth embodiment, only points different from the first to seventh embodiments will be described. To simplify the description, the fixed scroll 25 is turned to the orbiting scroll 3
The pressure for generating the pressing force is called a back pressure, and the space where the back pressure acts is called a back pressure chamber. As basic elements, a suction pressure-back pressure seal member 20 and a back pressure-discharge pressure seal member 21
, A fixed scroll support member 22, a forced circulation means 24 for lubricating oil, and its support member 23 are separately required. The fixed scroll 25 is disposed so as to be movable in a direction substantially perpendicular to the orbiting plane of the orbiting scroll 3, and is restrained by the fixed scroll support member 22 on the side opposite to the discharge space.

The fixed scroll support member 22 completely isolates the discharge space 16 from the inside of another sealed container 27. A back pressure chamber 28, a suction pressure-back pressure seal member 20, and a back pressure-discharge pressure seal member 21 are disposed on the side opposite to the discharge space of the fixed scroll support member 22, and the suction space 15- The configuration is such that leakage between the back pressure chamber 28 and the back pressure chamber 28 and the discharge space 16 is minimized.

In the compression operation, the point that a force for separating the fixed scroll 25 and the orbiting scroll 3 is generated by the pressure of the compressed working fluid is the same as in the first to seventh embodiments. In order to execute the operation, it is necessary to provide a pressing force acting in a direction in which the fixed scroll 25 and the orbiting scroll 3 are brought into close contact with each other by overcoming the above-mentioned separation force. In the eighth embodiment, in order to realize a pressing force acting means for appropriately pressing the fixed scroll 25 against the orbiting scroll 3, a back pressure which is a fluid pressure for generating a pressing force in a direction of bringing both scrolls into close contact with each other. The control valve 150 is used as a means for controlling the pressure. The configuration of the control valve 150 will be described with reference to FIG. The basic configuration is the same as in the first embodiment. The basic elements of the control valve 150 are a cylinder 151, a spring 152, a piston 153, a cap 154, a suction space 15, and a back pressure chamber 28 and a cylinder 151 which are respectively connected to a part of the fixed scroll 25. Main communication holes 155 and 156; and three sub communication holes 157, 158 and 159 connecting the discharge space 16, the suction space 15, the back pressure chamber 28, and the cylinder 151, respectively. The piston 153 has a shape in which a part of the contact surface with the cylinder 151 is dug into the center of the piston, and the dug part is called a piston dug portion 160. Piston 153 in cylinder 151
The main communication hole 155 between the suction space and the cylinder and the spring 152 are provided at one end in the piston movable direction, and the main communication hole 156 between the back pressure chamber and the cylinder is provided at the other end.

In FIG. 11, both main communication holes 155, 15
6 is always in communication with each space, and in the eighth embodiment, the cap 154 is connected to the back pressure chamber 28 of the cylinder 151.
The main communication hole 156 between the back pressure chamber and the cylinder
Is configured. In FIG. 11, the discharge space-cylinder sub-communication hole 157 and the suction space-cylinder sub-communication hole 158 are closed by the piston 153 on the cylinder 151 side. It communicates with the back pressure chamber-cylinder sub-communication hole 159 via the piston dug portion 160.

The back pressure chamber-cylinder sub-communication hole 159 communicates with the cylinder portion corresponding to the piston digging portion 160, so that the piston digging portion 1 is always maintained even when the piston 153 moves.
It is configured to conduct with 60. In the configuration according to the eighth embodiment, the closing plug 161 is used to seal the opening of the punched hole formed in the process of forming the back pressure chamber-cylinder sub-communication hole 159.

Since the basic configuration of the control valve 150 shown in FIG. 11 is the same as that of the first embodiment, the operation is also the same.
Therefore, the control valve 150 can reliably control the back pressure Pb within the target control value range according to Equation 6 according to the control law according to Equation 5. Although only one control valve 150 is shown in FIG. 11, a plurality of control valves may be provided. As described above, the control valve 150 is adaptable to a wide operating range without being affected by the motor speed, and enables reliable back pressure control.

The control valve 30 according to the first embodiment
Show the same operation as the control valve 150 according to the eighth embodiment, so that the control valves 50, 70, 90, 110, 130, and 130 shown in the second to seventh embodiments can be understood.
200 can be applied not only to a high-pressure closed-container scroll fluid machine but also to a low-pressure closed-container scroll fluid machine. Further, the conventional low-pressure closed-container scroll fluid machine requires a back-pressure increasing means. However, since the control valve 150 has an increasing function, it is not necessary to separately provide a back-pressure increasing means. This is a special effect when a control valve having a pressure increasing function is applied to a low-pressure closed-container scroll fluid machine.

[0071]

According to the present invention, it is possible to provide a scroll fluid machine which can secure high total heat insulation efficiency and high reliability over a wide operating range.

[Brief description of the drawings]

FIG. 1 is an overall view of a scroll fluid machine according to a first embodiment.

FIG. 2 is a configuration diagram of a control valve according to the first embodiment.

FIG. 3 is an explanatory diagram of an operation of the control valve according to the first embodiment.

FIG. 4 is a configuration diagram of a control valve according to a second embodiment.

FIG. 5 is a configuration diagram of a control valve according to a third embodiment.

FIG. 6 is a configuration diagram of a control valve according to a fourth embodiment.

FIG. 7 is a configuration diagram of a control valve according to a fifth embodiment.

FIG. 8 is a configuration diagram of a control valve according to a sixth embodiment.

FIG. 9 is a configuration diagram of a control valve according to a seventh embodiment.

FIG. 10 is an overall view of a scroll fluid machine according to an eighth embodiment.

FIG. 11 is a configuration diagram of a control valve according to an eighth embodiment.

FIG. 12 is an overall view of a scroll fluid machine according to a conventional technique.

FIG. 13 is a schematic sectional view of a compression chamber.

FIG. 14 is a configuration diagram of a control valve according to a conventional technique.

[Explanation of symbols]

2,49 ... orbiting scroll 3,25,29,48,63,86,106,125,
140, 213 fixed scroll 4 compression chamber 7, 26, 46, 47 frame 8, 28 back pressure chamber 9 Oldham ring 15 suction space 16 discharge space 22 fixed scroll support member 30, 50, 70, 90, 110, 130, 150, 1
70, 180, 190, 200 ... back pressure control valve

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kenji Tojo 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Inside the Air Conditioning Systems Division, Hitachi, Ltd. (72) Inventor Kazuo Sakurai 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Air Conditioning Systems Business, Hitachi, Ltd. Inside

Claims (12)

[Claims] An orbiting scroll member having a head plate and a spiral scroll wrap standing upright on the head plate, and rotating without rotating on a plane perpendicular to the axial direction in which the scroll wrap stands up; A non-orbiting scroll member having a head plate and a spiral scroll wrap erected on the head plate, and at least movement in an in-plane direction perpendicular to the axial direction is substantially restricted, the orbiting scroll member and the non-orbiting scroll member, A compression chamber whose volume is reduced by being substantially closed between the two scroll members, and the two scroll members being opposed to each other by a separating force in a direction of separating the end plates of the two scroll members due to the pressure of the fluid in the compression chamber. Means for applying a pressing force in a direction to bring the fluid into close contact with both scroll members, a suction path for introducing a fluid into the compression chamber, and a fluid pressurized in the compression chamber to the outside. And a driving means for orbiting the orbiting scroll member, wherein one end of a piston sliding in an axial direction in a cylinder disposed in a part of the non-orbiting scroll member is sucked. Pressure and spring force are applied, and the other end is subjected to a fluid pressure for bringing both scroll members applied to at least one part of the both scroll members into close contact with each other, and the suction pressure and the spring force and the fluid pressure are applied. Wherein the fluid pressure falls within a target control value range by moving the piston with the balance of the force of the scroll fluid machine. 2. The scroll fluid machine according to claim 1, wherein when the piston moves toward the end of the piston on which the suction pressure and the spring force act, the working space of the fluid pressure and the working space of the suction pressure are different from each other. A scroll fluid machine having a structure for conducting electric current. 3. The scroll fluid machine according to claim 1, wherein when the piston moves toward the end of the piston where the suction pressure and the spring force act, the structure communicates the working space of the fluid pressure with the compression chamber. A scroll fluid machine characterized by the following. 4. The scroll fluid machine according to claim 1, wherein when the piston moves toward the end of the piston on which the fluid pressure acts, the working space of the fluid pressure and the discharge pressure vary. A scroll fluid machine having a structure for conducting a working space. 5. A revolving scroll member having a head plate and a spiral scroll wrap standing upright on the head plate, and revolving without rotating on a plane perpendicular to an axial direction in which the scroll wrap stands upright. A non-orbiting scroll member having a head plate and a spiral scroll wrap erected on the head plate, and at least movement in an in-plane direction perpendicular to the axial direction is substantially restricted, the orbiting scroll member and the non-orbiting scroll member, A compression chamber whose volume is reduced by being substantially closed between the two scroll members, and the two scroll members being opposed to each other by a separating force in a direction of separating the end plates of the two scroll members due to the pressure of the fluid in the compression chamber. Means for applying a pressing force in a direction to bring the fluid into close contact with both scroll members, a suction path for introducing a fluid into the compression chamber, and a fluid pressurized in the compression chamber to the outside. Discharge path, and a scroll fluid machine provided with a driving means for orbiting the orbiting scroll member, wherein a suction pressure is applied to one end of a piston which slides in an axial direction in a cylinder provided in a part of the non-orbiting scroll member, A discharge pressure and a spring force are applied, and a fluid pressure is applied to the other end so that the two scroll members applied to at least a part of the two scroll members are brought into close contact with each other. A scroll fluid machine, wherein the fluid pressure is within a target control value range by moving the piston with a balance of a force due to the fluid pressure. 6. The scroll fluid machine according to claim 5, wherein when the piston moves toward the end of the piston where the suction pressure, the discharge pressure, and the spring force act, the working space of the fluid pressure and the suction pressure. A scroll fluid machine having a structure that communicates with a working space. 7. The scroll fluid machine according to claim 5, wherein when the piston moves toward the end of the piston where the suction pressure, the discharge pressure and the spring force act, the working space of the fluid pressure and the compression chamber are connected. A scroll fluid machine having a conductive structure. 8. The scroll fluid machine according to claim 5, wherein when the piston moves toward the end of the piston on which the fluid pressure acts, the working space of the fluid pressure and the discharge pressure vary. A scroll fluid machine having a structure for conducting a working space. 9. The scroll fluid machine according to claim 2, wherein the fluid pressure working space and the suction pressure working space are electrically connected to each other, and the fluid pressure working space is connected to the fluid pressure working space. A scroll fluid machine, wherein a structure for conducting the working space of the discharge pressure and a structure for conducting the working space of the fluid pressure and the compression chamber are formed by using a contact surface between the piston and the cylinder. 10. The scroll fluid machine according to claim 1, wherein a gap between the roots of the wrap tips of the scroll members when the orbiting scroll member is not turned is reduced to a target value of 15 μm or less. Features scroll fluid machinery. 11. The scroll fluid machine according to claim 1, wherein a fluid pressure applied to at least a part of at least one of the two scroll members for bringing the two scroll members into close contact with each other. Is controlled in the vicinity of a pressure larger than the suction pressure by a certain amount. 12. The scroll fluid machine according to claim 5, wherein a fluid pressure applied to at least one of the scroll members for bringing the two scroll members into close contact with each other and x is set to 0. As a positive number in the range of ~ 1, the sum of the pressure x times the suction pressure and the pressure 1-x times the discharge pressure, or the pressure x times the suction pressure and 1 times the discharge pressure
A scroll fluid machine wherein the control is performed in the vicinity of the sum of -x times pressure and a pressure having a fixed amount.