JPS62113883A - Vane type compressor - Google Patents

Abstract

PURPOSE:To enable the discharge capacity to be varied by providing a plurality of pistons engaging a notch of the vane side end face to chuck the vane in a pump housing without raising the temperature of discharged gas. CONSTITUTION:When intake pressure is reduced to extend a bellows 40 and open a valve 38, then pressure in a chamber 37 is reduced to move downward a control piston 28 so that a communicating hole 33 is opened to a discharging chamber 16 and discharging pressure is supplied to a chamber 20 through the communicating hole 33, an annular groove 22 and a communicating hole 21. Also, a piston 17 is slided toward a vane 6 by the discharging pressure and the rod 17a engages a notch 6a formed on the side end face of the vane 6 to chuck the vane 6. Thus, the spring-out of the vane 6 can be regulated to reduce discharge capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a vane compressor in which the number of vanes can be changed by chucking the vanes, thereby changing the discharge flow rate.

(Prior Art) This type of vane compressor has a simple structure and is suitable for high-speed rotation, so it is often used as a refrigerant compressor for vehicle air conditioners. As the rotor rotates, the vanes are brought into contact with the inner circumferential surface of the pump housing and rotated, thereby changing the volume of the pump chamber and sucking, compressing, and discharging fluid such as refrigerant.

By the way, when using this vane type compressor, it is economical to change the discharge flow rate according to the conditions of use, and various methods of varying the flow rate have been proposed in the past. For example, Japanese Patent Publication No. 58-57638 proposes a method of restraining the position of a vane using a control device equipped with an electromagnet.

(Problems to be Solved by the Invention) However, according to the conventional method, the variable mechanism is complicated and expensive, power loss is large, and if the flow rate is restricted, the discharge temperature of the fluid increases. there were.

The present invention has been made in view of the above problems, and its purpose is to provide a variable flow rate mechanism with a simple and compact structure, ensure reliable operation, and reduce power loss. To provide a vane type compressor that does not cause a rise in discharge temperature even when the flow rate is reduced.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a vane type compressor in which a plurality of vanes are inserted into a rotor so as to be movable back and forth.
Notches are formed in the side end surfaces of the vanes, and pistons that engage with the notches and chuck the vanes are provided in the number of vanes, and a control mechanism is provided to control the operation of the pistons.

(Function) If the control mechanism operates the piston to chuck the vanes, the discharge flow rate of the compressor decreases as the number of vanes chucked increases.

(Example) An example of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a longitudinal sectional side view of a vane type compressor according to the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG.
4 is an enlarged detailed view of section A in FIG. 1, FIG. 5 is a broken cross-sectional view explaining the action of the piston, and FIG. 6 (a).
(b), (c), and (d) are diagrams showing the chucking state of the vanes, and FIG. 7 is a diagram showing the relationship between the number of vanes chucking and the discharge flow rate.

The vane compressor 1 shown in FIGS. 1 and 2 is.

The compressor case 2 has a front head 2b tightly fitted to the front surface of a cylindrical case 2a with a bottom, and inside the compressor case 2 are a front side block 3a and a rear side block having a circular hollow part. 3b, tail block 3c
and a cam ring 3d having an elliptical hollow portion. A cylindrical rotor 5 fitted onto a rotating shaft 4 is fitted into the pump housing 3, and each of a plurality of (five in the illustrated example) slits 5a provided radially in the rotor 5. A plate-shaped vane 6 is inserted into the holder so that it can move forward and backward. A space surrounded by the inner surface of the pump housing 3, the outer peripheral surface of the rotor 5, and the vanes 6 constitutes a pump chamber 7. Note that a vane back pressure chamber 5b is formed at the bottom of each slit 5a provided in the rotor 5.

By the way, the rotating shaft 4 integrally has a large-diameter sub-rotor 4a at its rear part, and the front sight block 3a
, is rotatably supported by front and rear roller bearings 8.9 provided on the rear sight block 3b, respectively, and its front end is connected to the output shaft of a prime mover (not shown) that rotationally drives it. Further, the front shaft penetrating portion of the rotating shaft 4 is sealed by an oil seal 10, and a chamber 11 is formed inside the oil seal 10. This chamber 11 is connected to the rotor through a gap between the roller bearings 8. 5 and communicates with each vane back pressure chamber 5b.

On the other hand, a suction chamber 12 partitioned by a front side block 3a is formed inside the compressor case 2, and this suction chamber 12 is connected to a pump chamber through a suction port 13. It communicates with the intake part of No.7. Further, in the discharge portion of the pump chamber 7, a discharge boat 14.14 is provided on the cam ring 3d, as shown in FIG. A discharge pressure chamber 16 is defined between the inner peripheral surface and the inner circumferential surface of the vane.By the way, a rectangular notch 6a is formed in the side end surface of each vane 6, and corresponds to each vane 6 of the sub-rotor 4a. In the position, the vane 6 is engaged with the notch 6a of the vane 6.
A piston 17 for chucking is slidably fitted. The piston 17 includes a rod 17a that is somewhat eccentric with respect to the axis, and the tip of the rod 17a forms an inclined surface. The piston 17 is biased in one direction by a spring 18, and normally remains stationary apart from the vane 6 as shown in the figure. Further, chambers 19 and 20 are formed on the left and right sides of the piston 17, and one chamber 19 communicates with the vane back pressure chamber 5b.

The other chamber 20 communicates via a communication hole 21 with annular grooves 22 formed concentrically on the end surface of the sub-rotor 4a. The annular groove 22... is the dill block 3.
A seal ring 23 provided on the c side prevents communication between adjacent parts.

Each seal ring 23 is pressed toward the sub-rotor 4a by an elastic ring 24 provided on the tail block 3C, and each elastic ring 24 is formed on the tail block 3c as shown in FIG. It receives a discharge pressure Pd through a passage 25 that opens to the sub-rotor 4a, and a force acts on this in the direction of suppressing the seal ring 23 against the end surface of the sub-rotor 4a.

In this way, if the discharge pressure Pd is used as a means for suppressing the seal ring 23, a spring becomes unnecessary, and the structure becomes more compact and the number of parts is reduced compared to using a commonly used mechanical seal.

In addition, the tail block 3C has circular holes 26 and 27 with different diameters.
A control piston 28 is installed in the large diameter circular hole 26 through elastic rings 29 and 29' in an airtight manner.
The spring 30 is also fitted in a slidable manner.
In FIG. 1, it is elastically biased upward. The control piston 28 is prevented from coming off upward by a stopper pin 31. Note that a cylindrical piston chamber 32 is provided on the outer peripheral side of the control piston 28.
When the control piston 28 is at the upper limit position shown in the figure, this piston chamber 32 communicates with each annular groove 22 through a communication hole 33 bored in the tail block 3C, and also communicates with the tail block 3C. Communication hole 34 drilled in the center of block 3c and rear side block 3b
It communicates with each vane back pressure chamber 5b via a passage 35 bored in the vane. Incidentally, the circumferential wall of the circular hole 26 is provided with an annular groove 26a.
... is formed, and when the control piston 28 moves downward, the elastic ring 29 provided thereon opens into the annular groove 26a.
. . , the control piston 28 remains semi-fixed at that position.

Further, an orifice 36 is fitted in the small diameter circular hole 27, and a chamber 37 below the control piston 28 communicates with the discharge pressure chamber 16 via the orifice 36. Furthermore,
A port 27a is open on the side of the circular hole, and a valve 38 faces this port 27a. The valve 38 is attached to a bellows 40 housed in a cylindrical holder 39.

The bellows 40 is in contact with an adjusting screw 41 having passages 41a formed therein. Further, the bellows 40 is biased toward the adjusting screw 41 by a spring 42, thereby biasing the valve 38 toward the closing side. Furthermore, the holder 39
The inside communicates with the suction side of the pump chamber 7 via passages 41a provided in the adjustment screws 41. Further, the holder 39 functions as a positioning member for the rear sight block 3b and the tail block 3C.

Next, the operation of the vane type compressor 1 will be explained. During normal operation or startup, the valve 38 is closed, and therefore the discharge pressure Pd acts on both the upper and lower surfaces of the control piston 28.
is stopped at the upper limit position shown in the figure by the elastic force of the spring 30. In this state, the pressure Pk of the vane back pressure chamber 5b is the same as that of the passage 35, the communication hole 34, the piston chamber 32, all the communication holes 33..., the annular groove 22... and all the communication holes 21...
It is transmitted to all rooms 20... through..., and all rooms 20...
- is maintained at vane back pressure Pk.

On the other hand, the other chamber 19... is also the vane back pressure chamber 5 as described above.
b..., so the left and right sides of the piston 17 are kept at the same pressure, and due to the elastic force of each spring 18, all the pistons 17 are retracted as shown in the figure. Vane 6... is not chucked and is in a movable state. At this time, that is, when the number of vane chucking=0 in FIG. 7, the maximum discharge flow rate is obtained.

Next, when the compressor suction pressure Ps decreases and the bellows 40 exposed to this pressure Ps extends in the axial direction and the valve 38 opens, the pressure in the chamber 37 where the discharge pressure Pd has been acting until now decreases. The control piston 28 receives the discharge pressure Pd on its upper surface and moves downward. The amount of movement of the control piston 28 is determined by the absolute value of the suction pressure Ps, and the movement of the control piston 28 causes the communication holes 33...
* gradually opens into the discharge pressure chamber 16. First, when one communication hole 33 opens into the discharge pressure chamber 16, the discharge pressure Pd is increased by the communication hole 33. It is supplied to the chamber 20 through the annular groove 22 and the communication hole 21, and the piston 17 receives this discharge pressure Pd and slides in the direction of the vane 6, so that its rod 17a engages with the notch 6a provided in the vane 6. chucking the vane 6. This state is shown in FIG. 6(a), and in this state, that is, when the number of vane chucking=1, the discharge flow rate decreases as shown in FIG. 7.

If the control piston 28 moves abnormally downward, the number of communication holes 33 opening into the discharge pressure chamber 16 will gradually increase, and the number of vanes 6 to be chucked will increase in the same manner as described above. FIGS. 6(b), (c), and (d) respectively show the state where the number of vane chucking=2.3.4, and FIG. 7 shows the corresponding change in the discharge flow rate.

In the above, since the variable discharge flow rate mechanism has a simple structure, it is compactly housed within the compressor case 2, and since the working fluid pressure is used as a control medium, its operation is reliable. In addition, the flow rate is changed by chucking the vanes 6, and since the tips of the chucking vanes 6 do not come into sliding contact with the inner circumference of the pump housing 3,
Power loss can be reduced, and even if the flow rate is reduced, the discharge temperature will not rise.

However, in one or more embodiments, the vane 6 cannot be chucked unless it comes to the short diameter portion of the pump housing 3. Therefore, if the piston 17 operates while the vane 6 is at the long diameter portion, not only will chucking fail;
The protrusion of the rod 17a of the piston 17 prevents the vane 6 from entering the slit 5a. Therefore, the tip of the rod 17 of the piston 17 is made sloped as described above, and the vane 6 is
゛When the vane 6 comes into contact with this slope as shown in the figure, the piston 17 is retracted by a component force f2□ of the reaction force f2 caused by the force f□ that causes the vane 6 to enter the slit 5a, and the vane 6 is prevented from entering the slit 5a. can. After that, the rod 17a of the piston 17 is inserted into the notch 6a formed in the vane 6.
The tips of the vanes 6 are engaged and the vanes 6 are chucked. Further, the rod 17a of the piston 17 has an angle of δ as shown in FIG.
Since the piston 17 is eccentric, rotation of the piston 17 is prevented, and the slope of the rod 17a always faces upward.

Note that the bellows 40 for controlling the valve 38 actually varies in its elastic force.

This variation is eliminated by the adjusting screw 41.

(Effects of the Invention) As is clear from the above description, according to the present invention, a notch is provided in the vane, and a piston operated by a control mechanism is engaged with the notch to chuck the vane, thereby varying the flow rate. Therefore, the structure of the variable flow rate mechanism is simplified, power loss is reduced, and the discharge temperature does not increase even when the flow rate is reduced.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of a vane type compressor according to the present invention, Fig.
The figure is a cross-sectional view taken along the ■-■ line in Figure 1, and Figure 3 is the m-m line in Figure 2.
4 is an enlarged detailed view of section A in FIG. 1, FIG. 5 is a broken sectional view explaining the action of the piston, and FIGS.
b), (c), and (d) are diagrams showing the chucking state of the vanes, and FIG. 7 is a diagram showing the relationship between the number of vanes chucking and the discharge flow rate. 1... Vane type compressor, 2... Compressor case, 3...
・Pump housing, 4... Rotating shaft, 5... Rotor, 6... Vane, 6a... Notch, 7... Pump chamber, 16... Discharge pressure chamber, 17... Piston , 28・
...Control piston, 38...Valve, 40.
...Bellows.

Claims (4)

[Claims] 1. In a vane type compressor in which a plurality of vanes are inserted into a rotor so as to be movable back and forth, a notch is formed in the side end surface of the vane, and a piston that engages with the notch and chucks the vane is determined by the number of vanes. A vane type compressor characterized in that a vane type compressor is provided with a control mechanism for controlling the operation of the piston. 2. 2. The vane type compressor according to claim 1, wherein the piston has a rod that is eccentric with respect to the axis, and a tip of the piston that forms an inclined surface. 3. Claim 1, wherein the control mechanism is comprised of independent communication holes that supply pressure to the end faces of each piston, and a control piston that opens and closes each communication hole by sliding. vane type compressor. 4. The position of the control piston is regulated by an elastic ring fitted thereon engaging with a plurality of annular grooves formed on the inner periphery of the sliding surface of the control piston. The vane compressor according to item 3.