JPH037583Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is an oscillating compressor used in refrigerators, etc.
In particular, it relates to a variable capacity compressor.

(Prior Art) A rocking compressor is conventionally known in which the rotational motion of an inclined cam rotor is changed into rocking motion of a rocking plate, and this rocking motion causes a piston to reciprocate. . Furthermore, there is a compressor that changes the inclination angle of the above-mentioned inclined cam rotor to change the stroke amount of the piston connected to the rocking plate, thereby changing the compression capacity (compression ratio). .

By the way, in conventional variable capacity compressors, for example, the pressure difference between the crank chamber where the inclined cam rotor is installed and the suction chamber is adjusted, and this differential pressure is used to change the inclination angle of the inclined cam rotor. By changing the stroke amount of the piston, the compression capacity is changed.

(Problem to be solved by the invention) By the way, when using the above-mentioned differential pressure between the crank chamber and the suction chamber, the moment applied to the inclined cam rotor is adjusted by the urging force on the piston due to this differential pressure. The tilt angle of the tilt cam rotor is changed. In this case, there is a problem in the durability of the joint between the piston and the rod for connecting the piston to the rocking plate due to force being applied to the rear side (crank chamber side) of the piston.

On the other hand, in conventional variable displacement compressors, since the pressure in the crank chamber is controlled, the volume of the crank chamber is generally larger than that of the suction chamber, so the problem is that the response of the tilt angle of the tilt cam rotor is not sufficient. There is.

Furthermore, there is another problem in that when the differential pressure between the crank chamber and the suction chamber changes, oil flows out from the suction chamber.

(Means for Solving the Problem) According to the present invention, a swash plate disposed in the crank chamber is rotated by the rotation of the main shaft, and a oscillating plate that follows the inclined surface of the swash plate is oscillated. , a compressor that causes a plurality of pistons to reciprocate,
The main components include a rotor, a hinge mechanism that supports the swash plate on the rotor and transmits the rotation of the rotor to the swash plate, and a hinge mechanism connected to the swash plate so that the angle of inclination of the swash plate with respect to the main axis can be changed. , a slider disposed so as to be slidable on the main shaft, an actuator section linked to the slider via a thrust bearing, and a valve mechanism for controlling opening/closing of communication between the actuator section and the discharge chamber. By controlling the opening and closing of this valve mechanism, the high-pressure gas on the discharge side generates a force that acts on the actuator section in the axial direction of the main shaft, slides the slider in the axial direction of the main shaft, and changes the inclination angle of the swash plate. As a result, a variable capacity compressor is obtained, which is characterized in that the compression capacity is changed.

(Example) Hereinafter, the present invention will be explained by referring to an example shown in the drawings.

First, the structure of a variable capacity compressor according to the present invention will be explained with reference to FIG. 1 which is a first embodiment.

A cylinder block 2 in which a cylinder bore 2a is formed is formed at one end of the cylinder casing 1, and a through hole 3a for inserting a shaft shaft (main shaft) 4 is bored in the opening at the other end. A front housing 3 in which a radial bearing 5 for rotatably tilting the shaft shaft 4 is press-fitted is arranged and fixed in the through hole 3a.

A shaft shaft lead-out cylinder 3b is provided at the outer end of the through-hole 3a of the front housing 3 and protrudes to enclose the shaft shaft 4, and a space is formed by the shaft shaft 4 and the inner wall of the shaft shaft lead-out cylinder 3b. A mechanical seal 7 is arranged with the seal chamber 6 as the seal chamber 6. A crank chamber 1a is formed between the inner wall of the front housing 3 and one end surface of the cylinder block 2, and a cam rotor 8 is fitted into the side end of the shaft shaft 4 within the crank chamber 1a. One end of the cam rotor 8 is bent in the direction of the shaft shaft 4 and has an ear portion 8a formed in an ear shape. A long hole 8b is provided in this ear portion 8a.

A cylindrical member 9 having a flange portion 9a is inserted into the shaft shaft 4, and on one end surface of the flange portion 9a of this cylindrical member 9, an ear-shaped ear is formed toward the ear portion 8a of the rotor 8. A portion 9b is provided and has a hole 9c corresponding to the elongated hole 8b.
A pin-shaped member 91 is slidably inserted into the elongated hole 8b through the elongated hole 8b and the hole 9c, thereby forming a so-called hinge mechanism (pivot mechanism). Note that in this case, the cylindrical member 9 forms a swash plate. A ring-shaped rocking plate 1 is connected to the outer periphery of the cylindrical member 9 via a radial needle bearing 10.
1 is attached. At this time, the flange portion 9a
A slight gap is formed between and the swing plate 11,
A thrust race 12 is arranged on the flange portion 9a and the rocking plate 11, and a thrust needle bearing 13 is sandwiched between the thrust races 12.

Inner wall surface of front housing 3 and cam rotor 8
A thrust race 14 is arranged between them, and a thrust needle bearing 15 is sandwiched between the thrust races 14. On the other hand, the other end of the shaft shaft 4 is rotatably supported by a radial bearing 16 in the cylinder block 2.

A slide shaft 11a protruding toward the cylinder casing 1 is provided at the end of the rocking plate 11, and a slider groove 1b is provided in the cylinder casing 1 in correspondence with the slide shaft 11a. slider groove 1b
located within.

Further, one end of a piston rod 17 is rotatably supported on the swing plate 11.
is connected at its other end to a piston 18 located within the cylinder bore 2a. Note that a plurality of pistons having the above-described structure are provided along the circumference on the swing plate 11.

A suction hole 19 for sucking in fluid and a discharge hole 20 for discharging fluid are bored in one end surface of the cylinder bore 2a. A valve plate 21 to which a discharge valve and a discharge valve are connected is connected to the cylinder block 2 via a gasket 21a, and a suction chamber 23 is connected by a cylinder head 22 having a partition wall 22a.
The cylinder head 22 is inserted through a gasket (not shown) so that a discharge chamber 24 is formed.
It is placed on one end surface of the valve plate 21, the valve plate 21 and the cylinder head 22 are fixed on the cylinder block 2, and the cylinder casing 1 is closed.

A slider 25 is inserted into the shaft shaft 4 so as to be slidable on the shaft shaft 4.
The slider 25 is connected to the cylindrical member 9 of the slider 25 so as to be rotatable about the shaft axis and movable in the shaft axis direction, that is, to be freely movable. A coil spring 26 is attached between the left end surface of the slider 25 and the cam rotor 8.

As shown in the figure, a space (hereinafter referred to as a communication chamber) 27 is formed at the right end of the shaft shaft 4, and a disk-shaped plunger 28 is disposed so as to close this communication chamber 27. (In this case, the communication chamber 27 serves as a cylinder.) The plunger 28 is connected to the cylinder block 2 by a coil spring 29. in this case,
The communication chamber 27, the plunger 28, and the coil spring 29 constitute an actuator section. The right end surface of the slider 25 is connected to the plunger 28 via a thrust needle bearing 30, and the rotational force from the slider 25 is transferred to the plunger 28.
Pragya 28 while being careful not to convey it to 8.
The structure is such that the axial force from the slider 25 can be transmitted to the slider 25.

The communication chamber 27 is connected to the discharge chamber 24 through a communication hole 31, and a valve seat 32 is provided at the right end of the communication hole 31.
is provided. As shown in the figure, a solenoid valve 33 is disposed in the discharge chamber 24, and a valve portion 33a of the solenoid valve 33 is brought into contact with the valve seat 32.

Next, the operation of the compressor described above will be explained with reference to FIGS. 1 and 2.

First, referring to FIG. 1, when rotational motion is applied to the main shaft 4 by an engine or the like, the rotational motion is transmitted to the cam rotor 8 fitted to the main shaft 4, and this rotational motion is further transmitted to the cylindrical member 9. The signal is transmitted to the attached rocking plate 11. However, since the slide shaft 11a attached to the swing plate 11 slides within the slider groove 1b, the movement of the swing plate 11 in the rotational direction of the cam rotor 8 is prevented. Therefore, the cam rotor 8 causes the rocking plate 1 to
The rotational motion transmitted to the cylindrical member 1 is converted into a swinging motion by the rotation of the cylindrical member 9.

When the rocking plate 11 swings, the piston 1 is moved through the piston rod 17 connected to the rocking plate 11.
8 performs reciprocating motion. As a result, the suction port 34
The refrigerant gas sucked in from the cylinder passes through the suction chamber 23, is compressed in the cylinder bore 2a, and is discharged into the discharge chamber 24. This high-pressure compressed gas is then sent out to a refrigerant circuit (not shown) from a discharge port (not shown).

Here, referring to FIG. 2, if the gas force applied to each piston 18 in the compression stroke is F _pi , then all the pistons 18 (in the figure, only two pistons are shown, the solid line piston and the broken line piston, and the other pistons are shown) ) is omitted) is ΣF _pi , and this ΣF _pi acts to the left as shown. Further, the force with which the coil spring 26 presses the slider 25 to the right is F _SP , the force with which the plunger 28 presses the slider 25 to the left is F _c , the drag force of the pivot support part is F _L , and the force between the shaft shaft 4 and the slider 25 is F C . Let μ be the friction coefficient of
The relationship shown in equation (1) holds true.

ΣF _pi =F _L cosβ−F _c +μF _R +F _sp +F _p ...(1) However, β is the angle between the drag force F _L and the Y axis, F _P is the gas force applied to the back of the piston, and F _P =
n·πD ₂ /4·P _c (n: number of pistons, D: piston diameter, P _c : pressure in the crank chamber). Further, F _R indicates a component of the drag force F _L perpendicular to the shaft axis 4, and F _R =F _L sinβ (2).

By the way, the distance between the point of force P of the pivot support and the lower end of the shaft shaft 4 is _L1 , the distance between the point of force P and the total gas force ΣF _pi is _L2 , and the distance between the point of force P and the shaft axis is L2. is L ₃ , and the distance between the point of action P and component force F _R is
If L ₄ , then using the relationship shown in equation (1), the relationship shown in equation (3) holds regarding the moment with respect to the point of action P.

(ΣF _pi ×L ₂ = (F _sp −F _c )×L ₃ +μF _R ×L ₁ −F _R ×L ₄ +F _p ×L ₃ ...(3) The cylindrical member 9, that is, the swash plate is The slope slopes so that the moments are balanced as shown in equation (3).

Referring to FIGS. 1 and 2, when increasing the refrigerating capacity, the solenoid valve 33 is operated to connect the communication chamber 27 and the discharge chamber 24. Then, high-pressure compressed gas flows from the discharge chamber 24 to the communication chamber 27, and the pressure in the communication chamber 27 increases. As a result, the plunger 28 moves to the left in the communication chamber 27 due to the tension force of the coil spring 29 and the tension force of the coil spring 26.
The slider 25 also moves to the left. Since the slider 25 and the cylindrical member 9 are freely connected, the movement of the slider 25 causes a clockwise moment to be applied to the (3)
The cylindrical member 9 is tilted until the relationship shown by the formula is achieved.
That is, in this case, the inclination angle of the cylindrical member 9, that is, the swash plate increases (the inclination of the swash plate increases as the pin-shaped member 91 of the pivot mechanism moves toward the upper end of the elongated hole 8b). As a result, the stroke amount of the piston 18 attached to the rocking plate 11 increases, the compression capacity increases, and the refrigerating capacity increases.

On the other hand, when the solenoid valve 33 is operated to shut off the communication chamber 27 and the discharge chamber 24, the pressure in the communication chamber decreases, and the plunger 28 moves to the right by the pulling force of the coil spring 29. As a result, the slider 25 moves to the right, a counterclockwise moment is generated in the cylindrical member 9, and the inclination becomes shallow until the relationship shown in equation (3) is reached (the inclination angle of the swash plate is determined by the pivot mechanism). The inclination is reduced by moving the pin-shaped member 91 toward the lower end of the long hole 8b.) Therefore, the stroke amount of the piston 18 becomes smaller,
The compression capacity becomes smaller and the refrigeration capacity decreases.
Note that in order to maintain the swash plate at a constant inclination angle, it is necessary to maintain the pressure in the communication chamber 27 at a constant value, but this can be done by controlling the on/off duty ratio of the solenoid valve 33. Become.

FIG. 3 shows a second embodiment of the present invention.

In the compressor shown in FIG. 3, a bellows 35 is used as an actuator section, and this bellows 35 is connected to the discharge chamber 24 via a solenoid valve 33. In the compressor having this configuration, the slider 25 is moved by the expansion and contraction of the bellows 35, and the inclination angle of the cylindrical member 9 is changed.

(Effect of the invention) As explained above, in the variable capacity compressor according to the invention, the inclination angle of the swash plate is changed without using the differential pressure between the discharge chamber and the crank chamber, so that no force is applied to the back surface of the piston. without acting, therefore,
The durability of the compressor, especially the connection between the piston and the piston rod, is improved. There is also no problem with oil circulation. Furthermore, since the volume of the actuator section is extremely small, there is an advantage that responsiveness is extremely good when changing the compression capacity.

[Brief explanation of the drawing]

Figure 1 shows the first variable capacity compressor according to the present invention.
FIG. 2 is a cross-sectional view showing the embodiment of the variable capacity compressor according to the present invention, FIG. FIG. DESCRIPTION OF SYMBOLS 1... Cylinder casing, 1a... Crank chamber, 2... Cylinder block, 2a... Cylinder bore, 3... Front housing, 4... Main shaft (shaft shaft), 8... Cam rotor, 9... Cylindrical member, 10...Radial needle bearing,
11... Rocking plate, 17... Piston rod, 18
... Piston, 19 ... Suction hole, 20 ... Discharge hole, 22 ... Cylinder head, 23 ... Suction chamber, 24 ... Discharge hole, 25 ... Slider, 2
6, 29...Coil spring, 27...Communication chamber, 28
... Plunger, 31 ... Communication hole, 32 ... Valve seat, 33 ... Solenoid valve, 34 ... Suction port, 35
...Bellows.

Claims (1)

[Claims for Utility Model Registration] 1. A swash plate disposed in the crank chamber is rotated by the rotation of the main shaft, and a oscillating plate that follows the inclined surface of the swash plate is oscillated to cause a plurality of pistons to reciprocate. The compressor is configured such that a rotor provided on the main shaft and the swash plate are supported by the rotor so that an inclination angle of the swash plate with respect to the main axis can be changed, and the rotation of the rotor is controlled by the rotor. a hinge mechanism for transmitting the signal to the swash plate; a slider connected to the swash plate and disposed so as to be slidable on the main shaft; an actuator section linked to the slider via a thrust bearing; and the actuator section. and a valve mechanism for controlling opening and closing of communication with the discharge chamber, and controlling the opening and closing of the valve mechanism to generate a force acting on the actuator section in the axial direction of the main shaft by high pressure gas on the discharge side. A variable capacity compressor, characterized in that the slider is slid in the axial direction to change the inclination angle of the swash plate, thereby changing the compression capacity. 2 Utility Model Registration Claims Claim 1 provides that the actuator section includes a communication chamber communicating with the discharge chamber, and a plunger mechanism disposed in the communication chamber and linked to the slider via a thrust bearing. A variable displacement compressor, characterized in that the plunger mechanism is reciprocated, thereby causing the slider to slide and changing the inclination angle of the swash plate. 3 Utility Model Registration In the statement of Claim 1, the actuator section includes a bellows mechanism linked to the slider via a thrust bearing, and expands or contracts the bellows mechanism, thereby causing the slider to expand or contract. A variable capacity compressor, characterized in that the inclination angle of the swash plate is changed by sliding.