JPS63186982A - Vane type compressor - Google Patents

Abstract

PURPOSE:To prevent chattering by communicating a back pressure chamber and a discharge chamber via a blocking face closing the back pressure chamber and communicating the back pressure chamber and an intake chamber via a back pressure communicating groove. CONSTITUTION:A blocking face 24 and a back pressure communicating groove 25 are provided on the rotor 11 side end face of a front side block 9 and a rear side block 10 along the periphery of a bearing 13. When a vane 17 reaches the blocking face 24, a back pressure chamber 16 and a discharge chamber 21 are communicated, the vane back pressure approaches the discharge pressure, and the vane 17 is not separated from the inner periphery of a cam ring 8. When the vane 17 reaches the back pressure communicating groove 25, the back pressure chamber 16 and an intake chamber 19 are communicated, and the tip face of the vane 17 is not brought into contact with the inner periphery of the cam ring 8 with the pressure more than required. Accordingly, chattering of vanes can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vane compressor used as a refrigerant compressor for, for example, an automobile air conditioner.

(Prior art and its problems) A conventional vane type compressor has a cam ring whose both sides are closed with side blocks, a rotor rotatably disposed within the cam ring, and a vane groove of the rotor that is fitted so as to be freely retractable. and a vane that protrudes toward the outer peripheral side of the rotor due to the resultant force of centrifugal force and back pressure in a vane back pressure chamber, and a vane that is provided on the rotor side end surface of the side block and that the vane is located near the discharge hole of the cam ring. a closing surface that closes the back pressure chamber when the cam ring is closed; and a back pressure communication groove that is provided on the rotor side end surface of the side block and that communicates with the back pressure chamber when the vane is not located near the discharge hole of the cam ring. The compressor is configured to compress fluid by varying the volume of the compressor defined by the side block, rotor, and vanes.

The relationship between the vane back pressure Pc of the vane type compressor having the back pressure communication groove, commonly called a groove, and the rotation angle of the rotor is shown by the dotted line B in FIG. 9. As is clear from this dotted line B, the revane back pressure PK occurs when the vane is not near the discharge port on the inner peripheral surface of the cam ring, that is, when the rotor's back pressure chamber and the back pressure communication groove of the side block are in communication with each other. (The rotation angle of the rotor is 0 in Fig. 9)
degree to a degree), the approximately constant value P 1m1d (e.g. 7
~81Cg/a#). However, as the vane approaches the discharge port (discharge hole) on the inner circumferential surface of the cam ring, the pressure at the tip of the vane increases, so a downward force acts on the vane, causing it to move away from the inner circumferential surface of the cam ring. shall be. For this reason, in this type of vane type compressor, the back pressure chamber provided at the inner end of the vane groove is closed, and the vane back pressure Pc is reduced to the discharge pressure Pd (for example, 14 kg/cd).
I am trying to raise it to a value close to . When the rotor rotates further and the vanes are near the discharge port on the inner circumferential surface of the cam ring, that is, the rotation angle at which the back pressure chamber of the rotor and the closed surface of the side block begin to communicate (degree a in Fig. 9). ), the back pressure chamber begins to be blocked, and the vane back pressure PC rises rapidly, reaching the maximum value Pxmax at the rotation angle of the rotor where the vane is located at the discharge port, and when the blockage begins to be released, the vane back pressure PK increases. falls rapidly. After the blockage has been released (as shown in Figure 9), when the vane is no longer near the discharge port on the inner peripheral surface of the cam ring, that is, the rotor is connected to the back pressure chamber of the rotor and the back pressure communication groove of the side block. Since the angle of rotation is continuous (degrees to degrees C in FIG. 9), the vane back pressure PK becomes a substantially constant value Pt+aid.

After that, the same operation is repeated. Therefore, vane back pressure I
The maximum value P xmax of 't is expressed by the following equation.

Pt+aax=Ptm1d+a-(1
) (1) In the table, α indicates the pressure increased by the blockage of the back pressure chamber.

By the way, if the amount of gas leaking into the back pressure chamber is small, (
Since the vane back pressure PIid itself in equation 1) decreases, even if the back pressure chamber is blocked, P r+aax will decrease as a whole. That is, as shown by the dashed line C in FIG. 9, in the conventional example, Pxmax depends on mid, which is determined by the amount of gas leaking into the back pressure chamber.

Vane type compressors can be divided into fixed displacement type and variable displacement type, but what is common to both types is that the rotational power of the rotor is lost, and the reason for this is as shown below. be. As is clear from the dotted line B in Figure 9,
When the vane is near the discharge port on the inner peripheral surface of the cam ring,
That is, when the rotor is at a rotation angle where the back pressure chamber of the rotor and the closed surface of the side block are in communication (a in FIG.
degree to b degree and C degree to d degree), the wax is applied to a predetermined vane back pressure P in order to prevent the vane from separating from the inner peripheral surface of the cam ring.
It is necessary to ensure that This predetermined vane back pressure P tm
When the amount of gas leaking into the back pressure chamber is set to ensure ax, when the vane is not near the discharge port on the inner peripheral surface of the cam ring, in other words, when the rotor is in When the rotation angle is such that it communicates with the groove (O degrees to a degrees, B degrees to C degrees, and 6 degrees to 360 degrees in Figure 9).
In other words, the required vane back pressure P mid is set higher than the actually required pressure. Therefore,
Both fixed displacement and variable displacement vane type compressors have vane back pressure Pxmid set higher than necessary, so when the vane is not near the discharge port on the inner circumferential surface of the cam ring, the vane is placed on the inner circumferential surface of the cam ring. This results in the tip surface being pressed more than necessary, and the rotational power of the rotor is lost accordingly.

In the constant volume type, since the discharge volume is approximately constant, the amount of gas leaking into the back pressure chamber is also approximately constant, and the vane back pressure P 1 m
Since 1d does not drop much, there are relatively few cases in which the required vane back pressure Ptmax cannot be secured. Therefore, since the vane back pressure Ptmax is low, the vane does not move away from the cam ring inner peripheral surface and chattering occurs. Furthermore, the vane is less likely to protrude from the vane groove during startup.

However, in the case of a variable displacement type, when the discharge capacity decreases, the amount of gas leaking into the back pressure chamber also decreases, so the vane back pressure P tmid decreases, and therefore wax does not rise to P even if the back pressure chamber is closed. First, when the vane approaches the discharge port on the inner circumferential surface of the cam ring, the vane is overcome by the tip pressure of the vane and separates from the inner circumferential surface of the cam ring, causing chattering. Also, if the vane back pressure P trap raax is low, it will be difficult for the vane to protrude from the vane groove at startup, so a trigger valve etc. will be provided.

It is necessary to introduce discharge pressure into the back pressure chamber to increase the vane back pressure. For this reason, the structure of the compressor has become complicated.

(Object of the Invention) The present invention has been made in view of the above circumstances, and has a simple structure while preventing the occurrence of chattering.
It is an object of the present invention to provide a vane type compressor whose vanes easily protrude at startup and with little power loss.

(Means for solving the problems) In order to solve the above problems, the vane type compressor of the present invention has the following features:
A cam ring whose top side is closed by a side block, a rotor rotatably disposed within the cam ring, and a rotor fitted into a vane groove of the rotor so as to be able to protrude and retract. a vane protruding toward the outer circumferential side of the rotor; a closing surface provided on the rotor side end surface of the side block and closing the back pressure chamber when the vane is located near the discharge hole of the cam ring; and the side block. a back pressure communication groove provided on the rotor side end surface of the cam ring and communicating with the back pressure chamber when the vane is not located near the discharge hole of the cam ring, the groove being defined by the side block, the rotor, and the vane. In a vane type compressor that compresses fluid by changing the volume of the compressor, the back pressure chamber and the discharge chamber are communicated through the closed surface, and the back pressure chamber and the suction chamber are connected to each other through the back pressure chamber. They are communicated via a pressure communication groove.

(Function) When the rotor rotates and the vanes are located near the discharge hole and reach the closed surface, the back pressure chamber and the discharge chamber communicate with each other, and the discharge pressure is introduced into the back pressure chamber and the vane back The pressure approaches the discharge pressure, the tip surface of the vane does not separate from the inner circumferential surface of the cam ring, and the rotor rotates so that the vane passes the discharge hole and the back pressure chamber passes the closed surface. , when reaching the back pressure communication groove, the back pressure chamber and the suction chamber communicate with each other, and the vane back pressure leaks to the suction chamber side, the vane back pressure approaches the suction pressure, and the tip surface of the vane Do not contact the inner peripheral surface of the cam ring with more pressure than necessary.

(Example) Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

First, one embodiment of the present invention will be described based on FIGS. 1 to 3 and FIG. 9. FIG. 1 is a longitudinal cross-sectional view of a vane compressor according to the present invention, and in the figure, 1 is a housing, which is a cylindrical case 2 with one end open, and one end of the case 2 that closes the opening. It consists of a front head 4 attached with bolts 3. A discharge port 5 for refrigerant gas, which is a heat medium, is provided on the upper surface of the rear side of the case 2, and an inlet port 6 for refrigerant gas is provided on the upper surface of the front head 4. The discharge port 5 and the suction port 6 communicate with a discharge chamber and a suction chamber, respectively, which will be described later.

A compressor main body 7 is housed inside the housing 1 . The compressor main body 7 includes a cam ring 8, a front side block (side block) 9 attached to both open ends of the cam ring 8 so as to close the opening surfaces, a rear side block (side block) 10, and the cam ring 8. The main components are a circular rotor 11 rotatably housed inside the rotor 11, and a rotating shaft 12 of the rotor 11. It is rotatably supported.

The rotor 11 is provided with a plurality (for example, four) of vane grooves 15 at equal intervals in the circumferential direction along the radial direction, and a back pressure chamber 16 is provided at the inner end of each vane groove 15. Vanes 17 are provided in these vane grooves 15.
□ to 174 are fitted so as to be freely retractable along the radial direction.

The front side block 9 is provided with suction ports 18, 18 symmetrically offset by 180 degrees in the circumferential direction (see FIG. 2). The suction chamber 19 between the front head 4 and the front side block 9 and the gap chamber 14 are
are in communication.

Discharge ports (discharge holes) are provided on both side peripheral walls of the cam ring 8.
20, 20 are provided, and the discharge chamber 21 in the case 2 and the void chamber 14 communicate with each other via these discharge ports 2o. These discharge ports 20, 20 are provided with a discharge valve 22 and a discharge valve stop 23, respectively, as shown in FIG.

As shown in FIGS. 1 to 3, on the end surfaces of the front side block 9 and the rear side block 1o on the side of the rotor 11, there are closed holes at 180-degree symmetrical positions along the periphery of the bearings 13, 13 of the rotating shaft 12. A surface 24.24 and a back pressure communication groove 25.25 are provided respectively. Therefore, due to the rotation of the rotor 11, the back pressure chamber 1 provided in the rotor 11 is
The open surfaces at both ends of 6 are closed surfaces 24.24 and back pressure communication m2
Connects to 5°25. That is, when the vane 17 is located near the discharge port 20 on the inner circumferential surface of the cam ring 8, the open surfaces at both ends of the back pressure chamber 16 communicate with the closing surfaces 24, 24, closing the back pressure chamber 16, When the vane 17 is not located near the discharge port 20 on the inner peripheral surface of the cam ring 8, the open surfaces at both ends of the back pressure chamber 16 communicate with the back pressure communication grooves 25 and 25, and the back pressure chamber 16 Back pressure communication groove 25, 2
Connects to 5.

The front side block 9 is provided with a discharge pressure introduction path 26 that opens on one side to a closed surface 24 provided on the front side block 9 and on the other side opens on the discharge chamber 21 . A plurality of these discharge pressure introduction passages 26 may be provided, and a notch 17a is provided at the base end of the vane 17 so that the vane 17 does not close the opening on the closing surface 24 side of the discharge pressure introduction passage 26. is provided. Therefore, the open surface of the front side block 9 side end of the back pressure chamber 16 is the closed surface 2.
4, the discharge pressure Pd of the discharge chamber 21 is introduced into the back pressure chamber 16 via the discharge pressure introduction path 26 and the closing surface 24.

Further, the front side block 9 is provided with a back pressure leak path 27, one side of which opens into the back pressure communication groove 25 provided in the front side block 9, and the other side of which opens into the suction chamber 19. There is. Therefore, the back pressure chamber 16
When the open side end surface of the front side block 9 communicates with the back pressure communication groove 25, the vane back pressure in the back pressure chamber 16 flows into the suction chamber via the back pressure communication groove 25 and the back pressure leak path 27. 19, and the pressure inside the back pressure chamber 16 approaches the suction pressure Ps. Note that the passage cross-sectional area of this back pressure leak passage 27 is such that the vane back pressure Pg is equal to the suction pressure Ps.
It is set to always maintain a high value. However, this back pressure leak path 27 may not be provided when the vane back pressure is not very high.

Next, the operation of the vane compressor of the present invention having the above structure will be explained.

When the rotating shaft 12 is rotated in relation to the engine of the vehicle and the rotor 11 rotates clockwise in FIG. 2, each vane 171
~17. vane groove 1 due to centrifugal force and vane back pressure PK.
5 protrudes in the radial direction from the cam ring 5 and rotates together with the rotor 11 while its tip surface slides into contact with the inner circumferential surface of the cam ring 8;
In the suction stroke to expand the volume of the void chamber 14 divided by each vane 17□ to 17, refrigerant gas, which is a heat medium, is sucked into the void chamber 14 from the suction port 18, and the volume of the void chamber 14 is increased. The refrigerant gas is compressed in the compression stroke, and the discharge valve 22 is opened by the pressure of the compressed refrigerant gas in the discharge stroke at the end of the compression stroke, and the compressed refrigerant gas is delivered to the discharge port 2o.
, the discharge chamber 21 and the discharge port 5 successively to a heat exchange circuit of an air conditioner (not shown).

During operation of such a compressor, the relationship between the vane back pressure Pg and the rotation angle of the rotor 11 is shown by the solid line A in FIG. As is clear from this solid line A, the return back pressure Pχ is the vane 17. is not near the discharge port 20 on the inner peripheral surface of the cam ring 8, that is, when the rotor 11
The rotation angle (
When the rotation angle of the rotor 11 is from 0 degrees to a degree in FIG.

It becomes a substantially constant value Pcm1d (for example, Ps+2 to 3 kg).

As the tip surface of the vane 17 □ approaches the discharge port 20 on the inner circumferential surface of the cam ring 8 , the tip pressure of the vane 171 increases and tends to push the vane 171 down into the inner end of the vane groove 15 . However, when the vane 171 is near the discharge port 20 on the inner peripheral surface of the cam ring 8, that is, when the rotor 11 is in contact with the open surface of the back pressure chamber 16 on the side of the front side block 9 and the closed surface 24 of the front side block 9. When the rotation angle reaches the starting rotation angle (the rotation angle of the rotor 11 is a degree in FIG. 9), the back pressure chamber 16 and the discharge chamber 21 begin to communicate through the closed surface 24 and the discharge pressure introduction path 26, and the discharge pressure Pd increases. It is introduced into the back pressure chamber 16 from the discharge chamber 21 .

Therefore, the vane back pressure P in the back pressure chamber 16 rapidly increases and approaches the discharge pressure Pd, causing the vane 171 to move toward the discharge port 20.
The maximum value P tw at the rotation angle of the rotor 11 located at
+ax. Therefore, since the vane 171 has a high vane back pressure PK, the vane 17□ does not separate from the inner circumferential surface of the cam ring 8 even if it is located at the discharge port 20 on the inner circumferential surface of the cam ring 8.

Next, when the tip surface of the vane 17□ passes the discharge port 2o on the inner peripheral surface of the cam ring 8 and the vane 17□ is not near the discharge port 20 on the inner peripheral surface of the cam ring 8, that is, when the rotor 11 When the rotation angle (degrees to degrees C in Fig. 9) is reached where the open side end surface of the front side block 9 and the back pressure communication @25 of the front side block 9 begin to communicate, the back pressure chamber 16 and the suction chamber 19 are connected. The vane back pressure PK begins to communicate through the back pressure communication groove 25 and the back pressure leak path 27, and the vane back pressure PK leaks from the back pressure chamber 16 into the suction chamber 19. For this reason, the vane back pressure Pi rapidly decreases and vane back pressure P ID (for example, P s +
2 to 3 kg/aIF) and then kept approximately constant, and the same operation is repeated thereafter. .

Therefore, the maximum value P cmax of the vane back pressure Pi is calculated using the following formula %
Formula % In formula (2), β represents the pressure loss of the discharge pressure Pd due to passage resistance of the discharge pressure introduction passage 26.

In other words, equation (2) expresses the vane back pressure P t whose pressure is influenced by fluctuations in the amount of gas leaking into the back pressure chamber 16.
This shows that it is possible to obtain the vane back pressure Pi required by the position of the vane 17 by introducing the discharge pressure Pd, without depending on mid. Therefore, when the vane 17 is located at the discharge port 2o, which is a position that requires a high vane back pressure Px, the discharge pressure Pd is introduced into the back pressure chamber 16, and the vane back pressure PK is increased. Since the vane 17 does not separate from the inner circumferential surface of the cam ring 8, it does not cause chattering or the like.Furthermore, when the vane 17 passes the discharge port 20 and tries to protrude from the vane groove 15, for example, the trigger valve etc. There is no need to introduce the discharge pressure Pd into the back pressure chamber 16 to increase the vane back pressure Pi. By adjusting the vane back pressure PK as necessary in this way, the tip surface of the vane 17 and the inner circumferential surface of the cam ring 8 do not come into sliding contact with excessive pressure, thereby preventing power loss. becomes possible.

Next, other embodiments of the present invention will be described based on FIGS. 4 to 9.

FIG. 4 is a longitudinal sectional view of the vane type compressor of the present invention. In the figure, parts common to the embodiments of FIGS. 1 to 3 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

This embodiment differs from the embodiments shown in FIGS. 1 to 3 described above in that it is a variable capacity vane type compressor.

In Fig. 4, reference numeral 1 denotes a housing, which is a cylindrical case 2 with one end open, and a carrier head 4' which is attached to one end of the case 2 with a bolt (not shown) so as to close the opening.
It consists of A discharge port 5 for refrigerant gas, which is a heat medium, is provided on the upper surface of the front side of the case 2.
A refrigerant gas inlet 6 is provided on the upper surface of each of the refrigerant gases.

The rotor 11 is provided with a plurality (for example, five) of vane grooves 15 (see No. 5rJ!i) along the radial direction of the rotor 11 at equal intervals in the circumferential direction. ~17s are respectively fitted so as to be freely retractable along the radial direction.

As shown in FIGS. 4 and 5, a plurality of (for example, five) discharge ports 20' are provided on both side peripheral walls of the cam ring 8, and the case 2 is supplied through these discharge ports 20'. The discharge chamber 21 between the inner circumferential surface and the outer circumferential surface of the cam ring 8 and the compression chamber 14 are communicated with each other. These discharge ports 20' are provided with a discharge valve 22' and a discharge valve stop 23', respectively.

The closing surface 24 and the back pressure communication groove 25 are as shown in FIGS.
Unlike the embodiment shown in the figure, as shown in FIGS. 4 and 6, only the end face of the front side block 9 on the rotor 11 side is provided at 180-degree symmetrical positions along the periphery of the bearing 13 of the rotating shaft 12. It is a provision. For this reason, the rotor 11
As the rotor 11 rotates, it communicates with the open surfaces 24.24 at both ends of the back pressure chamber 16 provided in the rotor 11 and the back pressure communication grooves 25.25, which is similar to the embodiment described above.

The front side block 9 includes a discharge pressure introduction passage 26', one side of which opens to the closing surface 24 provided on the front side block 9, and the other side of which opens to the discharge chamber 21.
is provided. Also.

The vane 17 is connected to the closed surface 24 of the discharge pressure introduction path 26'.
Similar to the above embodiment, a notch 17a is provided at the base end of the vane 17 so as not to block the side opening.

Furthermore, one side of the front side block 9 is open to the back pressure communication groove 25 provided in the front side block 9, and the other side is between the inner peripheral surface of the cam ring 8 and the outer peripheral surface of the rotor. A suction introduction passage 27' is provided which opens into the space 19'. This space 19' communicates with the suction chamber 19 via the carrier side block 10.

As shown in FIG. 7, the rear side block 10 is provided with an annular recess 30 on its one side (rotor 11 side) surface, and an arc-shaped bypass port 31.31 is provided in the recess 30 in the circumferential direction. The suction chamber 19 and the void chamber 14 communicate with each other via these bypass ports 31, which are arranged symmetrically and offset by 180 degrees.

Furthermore, the bypass port 31°3 is located within this recess 3o.
A ring-shaped control member 32 for controlling the opening angle of 1 is fitted so as to be rotatable in forward and reverse directions. The outer peripheral edge of the control member 32 is provided with a symmetrical arc-shaped notch 33.33 offset by 180 degrees in the circumferential direction. Further, pressure receiving members 34, 34 in the shape of protrusions are integrally provided on one side of the control member 32 and symmetrically offset by 180 degrees in the circumferential direction. These pressure receiving members 34,34 are connected to the bypass port 3.
1゜31 and an arc-shaped pressure working chamber 35゜3
5 (see FIG. 8).

The inside of these pressure working chambers 35 is controlled by the pressure receiving member 34.
It is divided into two chambers 351 and 35□, and the first chamber 3
51 communicates with the suction chamber 19 through the suction port 18 and the bypass port 31, and the second chamber 35□ communicates with the suction chamber 19 and the discharge chamber 21 through the communication path 36 and the orifice 37, respectively. The one second chamber 35□ and the other second chamber 35□ communicate with each other via a communication path 38. As shown in FIGS. 4 and 5, the communication passage 38 includes a pair of communication holes 38a, 38a provided symmetrically across the center of the boss portion 10a projecting from the center of the side surface opposite to the rotor of the rear side block 10. and an annular cavity 38b defined between the protruding end surface of the boss portion 10a and the inner surface of the rear head 4'. The communication holes 38a, 38a
One end of each opens into the second chambers 35□, 35□, and each other end opens into the annular cavity chamber 38b.

Note that the communication passage 36 is provided inside the rear side block 10.

A specially shaped seal member 39 is attached to the center of one side of the control member 32 and to both end faces of the pressure receiving member 34 . As shown in FIG. 8, the sealing member 39 closes the first
The space between the chamber 351 and the second chamber 35□ is also the seventh chamber.
As shown in the figure, the inner and outer circumferential surfaces of the control member 32 and the inner and outer circumferential surfaces of the annular recess 30 of the rear side block 10 are airtightly sealed.

The control member 32 uses a coil spring 40, which is a biasing member, in a direction (
(clockwise in FIG. 7). This coil spring 40 is fitted onto the outer peripheral side of the boss portion 10a of the rear side block 10 that extends toward the suction chamber 19 side. This coil spring 40 has one end connected to the boss portion 10a and the other end connected to the control member 32, respectively.

A valve mechanism 41 is provided in the communication path 36. The valve mechanism 41 switches in response to the pressure on the suction chamber 19 side (low pressure chamber side), and includes a bellows 42, a valve body 43,
It consists of a ball valve body 44 and a spring 45 that biases the ball valve body 44 in the valve closing direction. The bellows 42 is connected to the suction chamber 1.
9 and is arranged to be extendable and retractable with its axis parallel to that of the rotating shaft 12. The bellows 42 contracts when the pressure on the side of the suction chamber 19 is above a predetermined value, and expands when the pressure is below a predetermined value. The valve body 43 is airtightly fitted into a fitting hole 46 provided in the rear side block 10 so as to communicate orthogonally with the communication passage 36 . The valve body 43 has an internal space inside the valve body 43 and the suction chamber 1.
Communication holes 43a and 43b are bored to communicate with the fitting hole 9 and the fitting hole 46, respectively. The ball valve body 44 is the valve body 4
3, one end of which is biased by the spring 45 in the direction of closing the communication hole 43a, and the other end of which is biased by the bellows 4
The shaft 42a protrudes from the shaft 42a. When the pressure on the suction chamber 19 side is above a predetermined value and the bellows 42 is in a contracted state, the ball valve body 44 is moved by the spring 45.
The communication hole 43a is closed to connect the suction chamber 19 and the communication path 3.
6 is occluded. Further, when the pressure on the suction chamber 19 side is below a predetermined value and the bellows 42 is in an expanded state, the ball valve body 44 is moved by the shaft 4.2a of the bellows 42 against the spring force of the spring 45 to close the communication hole. By opening 43a, the suction chamber 19 and the communication passage 36 communicate with each other.

Next, we will explain the operation of the vane type compressor of the present invention having the above configuration. When the zero rotation shaft 12 is rotated in relation to the vehicle engine etc. and the rotor 11 is rotated clockwise in FIG. 5, each vane 171 175 protrudes radially from the vane groove 15 due to centrifugal force and vane back pressure P, and rotates integrally with the rotor 11 while its tip surface slides on the inner circumferential surface of the cam ring 8.

Each vane 17□~17. In the suction stroke to expand the volume of the gap chamber 14 divided by The gas is compressed, and in the discharge stroke at the end of the compression stroke, the pressure of the compressed refrigerant gas opens the discharge valve 22', and the compressed refrigerant gas is delivered to the discharge port 2.
0', the discharge chamber 21, and the discharge port 5 are sequentially valved and supplied to a heat exchange circuit of an air conditioner (not shown).

During operation of such a compressor, the pressure in the suction chamber 19, which is on the low pressure side, is introduced into the first chamber 351 of both pressure working chambers 35, 35 through the suction port 18,
Also, the pressure inside the discharge chamber 21, which is the high pressure side, flows through the orifice 37.
through both pressure working chambers 35.35 and the second chamber 35□
, 35□. Therefore, the force (control member 3
2 bypass port 31. pressure in the second chamber 352 (force to press the control member 32 in the direction that increases the opening angle of the bypass port 31, that is, force to rotate it clockwise in FIG. The control member 32 rotates in response to the pressure difference between the pressing force (that is, the force for rotating counterclockwise in FIG. 7), and controls the opening angle of the bypass port 31 to determine the compression start time. This is to control the discharge volume. That is, the opening angle of the bypass port 31 is determined by the pressure inside the first chamber 351 and the spring 40.
The control member 32 is rotated in response to changes in the pressure (suction pressure) in the suction chamber 19, which is the low pressure side. Since the position changes continuously, continuous variable capacity control of the compressor is possible.

Therefore, such a vane type compressor that can continuously control the capacity of the compressor automatically enters a low capacity operation depending on the operating condition of the compressor.

For example, when the compressor is in a high-speed operating state, the suction pressure in the suction chamber 19 decreases, so the bellows 42 of the valve mechanism 41 expands and presses the ball valve body 44 against the biasing force of the spring 45. Passage 36 opens. As a result, the pressure in the second chamber 352 leaks into the suction chamber 19, which is the low pressure side, through the communication path 36, so the pressure in the second chamber 35□ rapidly decreases, and as a result, the control The member 32 immediately rotates clockwise in FIG. 7, and the notch 33 of the control member 32 matches the bypass port 31, so that the bypass port 31 opens as shown by the two-dot chain line in FIG. do. Therefore, since the refrigerant gas sent from the suction port 18 into the cavity chamber 14 passes through the bypass port 31 and leaks into the suction chamber 19, the compression start time is delayed by the amount that the bypass port 31 opens, and the inside of the cavity chamber 14 is delayed. Since the amount of compressed refrigerant gas in the compressor decreases, the discharge capacity of the compressor decreases and the compressor becomes partially operational.

If the partially operating state continues in this manner, the amount of refrigerant gas flowing into the back pressure chamber 16 decreases because the discharge capacity is small. As the tip end surface of the vane 17 approaches the discharge port 20 on the inner circumferential surface of the cam ring 8, the tip pressure of the vane 17 increases. Chattering or the like occurs near the inner peripheral surface of the cam ring 8 away from the inner peripheral surface.

For this reason, vane compressors capable of variable capacity control also have major drawbacks. However, since the other functions of this embodiment are the same as those of the embodiment shown in FIGS. , is obtained by introducing the discharge pressure Pd and the suction pressure Ps to the pressure required depending on the position of the vane 17 in the cam ring 8. Therefore,
Chattering may occur, a trigger valve or the like may be provided to make it easier for the vane 17 to protrude from the vane groove 15, and the tip surface of the vane 17 and the inner circumferential surface of the cam ring 8 may not come into sliding contact with each other due to excessive pressure, thereby reducing power loss. It is possible to prevent this.

(Effects of the Invention) As detailed above, the vane compressor of the present invention communicates a back pressure chamber and a discharge chamber through a closed surface, and maintains a back pressure between the back pressure chamber and the suction chamber. Since the communication is established through the communication groove, the rotor rotates and the vane is located near the discharge hole on the inner peripheral surface of the cam ring, so that the back pressure chamber provided in the rotor communicates with the back pressure chamber. When reaching the closed surface that does not communicate with the groove, the back pressure chamber and the discharge chamber communicate with each other, discharge pressure is introduced into the back pressure chamber, the vane back pressure approaches the discharge pressure, and the vane The rotor rotates and the vane moves away from the vicinity of the discharge hole on the inner circumferential surface of the cam ring, and the back pressure chamber passes past the closed surface, reducing the back pressure. When reaching the communication groove, the back pressure chamber and the suction chamber communicate with each other, and the vane back pressure leaks and approaches the suction pressure. Therefore, the tip surface of the vane is under more pressure than necessary, and the inner periphery of the cam ring is Do not touch the surface.

Therefore, chattering does not occur, and there is no need to provide a trigger valve or the like to introduce discharge pressure into the back pressure chamber to increase the vane back pressure and make the vane easier to protrude.

Furthermore, there is less power loss.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention. FIG. 1 is a vertical sectional view of a vane type compressor, and FIG.
3 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIGS. 4 to 8 show other embodiments of the present invention. Figure 1 is a longitudinal cross-sectional view of the circular shape, Figure 5 is a cross-sectional view along the line ■-■ in Figure 4, and Figure 6 is a vertical cross-sectional view of the circular shape in Figure 4.
7 is a cross-sectional view taken along line VI in FIG. 4, FIG. 8 is a cross-sectional view taken along line ■-■ in FIG. 4, and FIG.
The figure is a characteristic diagram showing the relationship between vane back pressure and rotor rotation angle. 8...Cam ring, 9...Front side block (side block), 10...Rear side block (
side block), 11... rotor, 15... vane groove, 16... back pressure chamber, 171-17. ... Vane, 19... Suction chamber, 20.20'... Discharge port (
discharge hole). 21...Discharge chamber, 24...Closing surface, 25...Back pressure communication groove.

Claims (1)

[Claims] 1. A cam ring whose both sides are closed by side blocks, a rotor rotatably disposed within the cam ring, and a rotor fitted into a vane groove of the rotor so as to be able to protrude and retract. a vane protruding toward the outer circumferential side of the rotor; a closing surface provided on the rotor side end surface of the side block and closing the back pressure chamber when the vane is located near the discharge hole of the cam ring; and the side block. a back pressure communication groove provided on the rotor side end surface of the cam ring and communicating with the back pressure chamber when the vane is not located near the discharge hole of the cam ring, the groove being defined by the side block, the rotor, and the vane. In a vane type compressor that compresses fluid by changing the volume of the compressor, the back pressure chamber and the discharge chamber are communicated through the closed surface, and the back pressure chamber and the suction chamber are connected to each other through the back pressure chamber. A vane type compressor characterized by communication via a pressure communication groove.