JPH033996A - Variable-displacement compressor - Google Patents

Abstract

PURPOSE:To easily rotate a control member at the time of a start and improve startability by providing an opening/closing valve opened when the difference between the discharge pressure and the control pressure is small and guiding the discharge pressure into the high- pressure chamber of a pressure operating chamber. CONSTITUTION:The pressure receiving section 26 of a control member is located at the extreme position of the partial operation side of a pressure operating chamber 23 when a compressor is started, the ball valve body 38C of an opening/closing valve 38 is located at the opened position by the exciting force of a spring 38d until the discharge pressure Pd reaches the preset value, the opening/closing valve 38 opens a communicating hole 38a, and the discharge pressure Pd is guided into a high-pressure chamber 23 via the communicating hole 38a. The pressure receiving section 26 is smoothly slid to the full operation position side by the introduction of the discharge pressure Pd, because the fastening margin of a seal member 27 is small and the friction resistance is small. When the discharge pressure Pd reaches the preset value into the stationary operation state after a start, the ball valve body 38c is displaced, and the communicating hole 38a is closed. The discharge pressure with the preset value or above is prevented from being guided into the high-pressure chamber 23, and the normal pressure control by the discharge pressure Pd from only an orifice 28 is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a variable displacement compressor, and more particularly to a variable displacement compressor with improved startability.

(Prior Art) Conventionally, a pressure working chamber is provided in a pair of side blocks forming a cylinder and communicates with a low pressure chamber side and a high pressure chamber side. A first chamber communicating with the chamber side and a second chamber communicating with the high pressure chamber side.
a control member having a pressure-receiving portion slidably fitted so as to be airtightly partitioned into a chamber; A variable displacement compressor in which a pressure receiving part rotates to control the compression start timing and variably control the discharge capacity is disclosed in Japanese Patent Laid-Open No. 6, for example.
2-20688.

(Problems to be Solved by the Invention) In the variable displacement compressor having the above configuration, a sealing member is attached to the periphery of the pressure receiving portion of the control member, and the sealing member is provided with a substantially constant interference with the inner wall of the pressure working chamber. Hold it close, 11?
The pressure receiving part is made to be slidable while maintaining the airtightness of the first and second spaces.

However, when the compressor is started, due to the frictional resistance between the sealing member and the pressure (1' moving chamber), the sliding ability of the control member from the partially operating position to the fully operating position is insufficient, resulting in a decrease in the discharge amount. There was a problem that a rapid increase could not be obtained and the desired starting performance could not be obtained.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a variable displacement compressor in which a control member can be easily rotated when the compressor is started, thereby improving start-up performance. do.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a second suction boat provided in a side block having a suction boat of a pair of side blocks forming a cylinder, and a pressure working chamber provided in a side block having a boat and communicating with the low pressure chamber side and the high pressure chamber side; a first chamber in which the pressure 11' movement chamber within the pressure working chamber communicates with the low pressure side; a second chamber communicating with the high-pressure chamber side; and a control member having a pressure receiving part fitted in a slidable manner so as to be airtightly partitioned into a second chamber communicating with the high-pressure chamber side; In a variable capacity compressor configured to variably control the discharge capacity by rotating the pressure receiving part of the control member in response to the compression start timing, when the difference between the discharge pressure and the suppressing pressure is small. An on-off valve is provided which opens and introduces discharge pressure into the high pressure chamber of the pressure operating chamber.

(Function) When the compressor is started, the on-off valve is opened until the discharge pressure reaches a predetermined value, the discharge pressure is introduced into the high pressure chamber of the pressure working chamber, and the control member quickly rotates to the fully operating position 16 side.

This improves start-up performance.

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

FIG. 1 is a longitudinal cross-sectional view of a variable-field single-generation vane compressor according to an embodiment of the present invention, taken at an angle of 45 degrees passing through the axis.

As shown in FIGS. 1 and 2, the variable displacement vane type compressor includes a cam ring l having a substantially elliptical inner circumferential portion 1a, and a cam ring l having a substantially elliptical inner circumferential portion 1a, and a cam ring l having a substantially elliptical inner circumferential portion 1a, and a cam ring l having a substantially elliptical inner circumferential portion 1a, and a cam ring l having a substantially elliptical inner circumferential portion 1a, and a cam ring l having a cam ring l having a substantially elliptical inner peripheral portion 1a, and a cam ring l having a substantially elliptical inner circumferential portion 1a, and a cam ring l having a substantially elliptical inner peripheral portion 1a, and a cam ring l having a cam ring l having a substantially elliptical inner peripheral portion 1a, and a cam ring l having a substantially elliptical inner circumferential portion 1a. A cylinder consisting of a fixed front side block 3 and a rear side block 4, a cylindrical rotor 2 rotatably housed in the cylinder, and a front cylinder fixed to the outer ends of both side blocks 3 and 4, respectively. head 5
The main components are the rear head 6 and the rotating shaft 7 of the rotor 2, and the rotating shaft 7 is connected to both the side blocks 3 and 4.
It is rotatably supported by 111 receivers 8 and 9 provided respectively.

A discharge port 5a for refrigerant gas, which is a heat medium, is formed on the upper surface of the front head 5, and an intake port 6a for refrigerant gas is formed on the upper surface of the rear head 6, respectively. The discharge port 5a communicates with a discharge chamber 10 defined by the front head 5 and the front side block 3, and the suction 116a communicates with a suction chamber II defined by the rear head 6 and the rear side block 4.

As shown in FIG. 2, two compression spaces 12 and 12 are symmetrically defined between the inner circumference la of the cam ring l and the outer circumference of the rotor 2 and are offset by 180 degrees in the circumferential direction. There is. The rotor 2 is provided with a plurality (for example, 5) of vane grooves 13 along its radial direction at equal intervals in the circumferential direction, and vanes 14. ~14. are fitted in such a way that they can appear and retract freely along the radial direction.

61, the rear side block 4 is provided with a suction boat 15 at a symmetrical position offset by 180 degrees in the circumferential direction, as shown in FIGS. 1 and 4.
Since this is a longitudinal sectional view taken at an angle of 5 degrees, only one suction boat 15 is visible in FIG. 1). Each suction boat 15 extends through the rear side block 4 in the thickness direction, and the suction chamber 11 and each compression space 12 communicate with each other via each suction boat 15.

As shown in FIGS. 1 and 2, the outer peripheral wall of the cam ring 1 is provided with a plurality of discharge boats 16, for example, two discharge boats 16, which are symmetrically bored by 180 degrees in the circumferential direction. . A discharge valve cover 17.17 having a valve stop portion 17a is attached to a bolt 18 on the outer peripheral wall of the cam ring l where the discharge boat 16 is located.
are fixed respectively. Discharge valves 19 held on the discharge valve cover 17 side are interposed between the outer circumferential wall of the cam ring l and the valve 11-meeting portion 17a, and each discharge valve 1 receives discharge pressure. UN frt, each discharge boat 1
G is opened respectively. Further, the cam ring l has communication passages 20 that communicate with each discharge boat 16 when the discharge valves 19 are opened, and the front side block 3 has communication passages 21 that communicate with the communication passages 20 in the circumferential direction.
They are formed at approximately symmetrical positions offset by 80 degrees. Then, when each discharge boat I6 is ill D, the compressed refrigerant gas in the compression space 12 is discharged from the discharge boat! 6,
It is configured to be discharged sequentially through the communication path 20.2+, the discharge chamber IO, and the discharge II 5 a.

As shown in FIGS. 1 and 4, the rear side block 4
is provided with an annular recess 22 at its end on the rotor 2 side, and within the annular recess 22 two pressure working chambers 23 are provided at symmetrical positions offset by 180 degrees in the circumferential direction.

A ring-shaped control member 24 is fitted within the annular portion 22 so as to be rotatable in forward and reverse directions.

The 117191 member 24 is for controlling the compression start timing of each compression space 12, and is provided with arc-shaped notches 25 on its outer periphery at symmetrical positions offset by 18 of in the circumferential direction. 1 in the circumferential direction on one side of the control member 24.
A projecting piece-shaped pressure receiving part 26 is integrally provided at a symmetrical position controlled by 80 degrees, and the pressure receiving part 2G increases the pressure 11' in the moving chamber 23.
There are 23 low pressure chambers inside! and a high pressure chamber 232. As shown in FIG. 1, a seal member 27 is attached to the periphery of the pressure receiving part 26. A portion of the inner wall of the pressure working chamber 23 that corresponds to a partial operating position (36.36 in Fig. 5), which will be described later.
The gas in the low pressure chamber 231 and the gas in the high pressure chamber 232 do not leak from each other, and as shown in FIG. The pressure receiving portions 26 are provided so as to be able to slide into the electrodynamic 23 for each force f1. ) front end (fi+251) is provided at a symmetrical position offset by 180 degrees in the circumferential direction. Each low pressure chamber 231
communicates with the suction chamber 11 via the suction boat 15, and a low suction pressure I's is introduced into each paper pressure chamber 23+.

On the other hand, one of the high pressure chambers 232, 232 is connected to an orifice 28 and a communication passage 29 provided in the rear side block 4, respectively.
and the communication passage 20 provided in the cam ring 1 via a control pressure supply boat 30 provided in the cam ring 1. Further, the high pressure chambers 232 communicate with each other via a communication passage 31 provided in the rear head 6. Therefore, when each discharge boat 16 opens (1), the high pressure refrigerant gas discharged from the compression space 12 also flows into the discharge boat 1 (1).
5. Communication path 20, control pressure U (supply boat 30, communication path 2≦
) and is introduced into one of the high pressure chambers 23° through the orifice 28, and is introduced into the high pressure chamber 23° through the communication passage 31.
．． Also introduced into each hyperbaric chamber 23. A control pressure Pc is formed within.

In addition, the high pressure chamber 23. , 23. As shown in FIG. 1, one side can communicate with the second suction chamber through a communication passage 32 and an opening/closing mechanism 33 provided inside the rear side block 4. The opening/closing valve machine 33 opens and closes in response to the suction pressure Ps in the suction chamber 11, and when the valve is opened, the high pressure chamber 23. It leaks the control pressure Pc inside to the suction chamber 11 side, and includes a bellows 33a, which is a pressure responsive part, a case 33b, a ball valve body 33c, and a spring that biases the ball valve body 33c in the direction of the closing valve. 33d.The bellows 33a is disposed in the suction chamber 11 so as to be expandable and retractable, and the case 33b is attached to the mounting hole 34 provided in the rear side block 4 and communicating with the communication passage 32. 3
3a is reduced when the suction pressure Ps is equal to or higher than a predetermined value WL (for example, 2 kg/ant) set by the adjustment member 33e, and at this time the ball valve body 33c closes the central hole 33f of the case 33b. On the other hand, when the suction pressure Ps is below a predetermined value, the bellows 33a expands and the ball valve body 33c opens the central hole 33f. At this time, the high pressure chamber 23. The -ka is
It communicates with the suction chamber 11 through the communication passage 32, the mounting hole 34, the hole 33g in the case 33b, the chamber 33t1 in the case 33I), and the central hole 33r in the case 33b. A plunger 37 is fitted into the n-through hole 39 formed in the rear side block 4, and the discharge pressure I) d introduced from the high pressure chamber 232 through the high pressure introduction hole 40 moves the ball valve body 33c in the valve closing direction. The bulb is in contact with the body 33c so as to be biased.

As shown in FIG. 1, a torsion coil spring 35 is provided within the suction chamber II. This torsion coil spring 3
5 is disposed around the boss portion 4a of the rear side block 4, and one end 35a thereof is connected to the control member 2 as shown in FIG.
4, and its pond end 35b is locked to the boss portion 4a as shown in FIG.

As shown in Fig. 5, the range of angle O (e.g. 20°) extending from one end of the partially operating side of both pressure working chambers 23 and 23 (only one shown) to a2 is enlarged by increasing the width of the inner wall. The inner width part is 36.36. The enlarged inner width part 36.36
is to reduce the interference between the pressure receiving part 26 and the sealing member 27 (
For example, set it to 0.2 points for 0.5 mm of the enlarged inner width portions 36, 36) jI! This is to reduce frictional resistance, and is provided so that the pressure receiving part 26 can smoothly move from the partially operating position to the fully operating position when the compressor is started. Furthermore, due to the reduction in frictional resistance, the possible partial operation position of the pressure receiving part 26 at low load shifts to the right side in FIG. The I ratio (rotation range of the control member 24) increases, and the controllability improves. Also, ff/f:
Since the J9 member can be easily rotated from the fully operating position side to the partially operating position side, it is possible to set the set load of the screw recoil spring that forces the pressure receiving part to a small value, and therefore the Responsiveness can be further improved.

As shown in detail in FIG. 5, a communication hole 38a that communicates with the high pressure chamber 2:32 is formed in the rear side block, and an opening/closing knob p38 for opening and closing the communication hole 38a is connected to the rear body housing cylinder portion 38.
A ball 11 body 38c that deviates between the valve open position and the valve closed position shown in the figure in b, a spring 3Rd that biases the ball valve body 38c and the open valve toward the position r, and the ball valve body 38c It consists of a latch 11 and a pin 38e that lock the valve in the open position. Spring 3
8d, the difference ΔP between the discharge pressure Pd and the control pressure Pc is a predetermined value (3
kg/c++I) or less, the ball valve body 38c opens the communication hole 38a, and when ΔP is greater than a predetermined value, the ball valve body 3
The set load is set so that 8c closes the communication hole 38a.

In general, the amount of discharge pressure refrigerant gas supplied from the compression space 12 to the high pressure chamber 232 is determined by the amount of refrigerant gas inside the high pressure chamber 232) I: Force 1) Here, in the conventional configuration shown in FIG. 7 in which the on-off valve 38 of the present invention is not provided, the high pressure chamber 23 is
S is the cross-sectional area of the communication passage that supplies the discharge pressure 1) d to 2, and the cross-sectional area of the communication passage (central hole 33f) that discharges the internal pressure Pc of the high pressure chamber 232 to the suction chamber 11 via the on-off valve mechanism 33 is S. S'
Then, the following equation holds true.

If the predetermined value of the suction pressure Ps controlled by the opening/closing intermediary device tf't 33 is, for example, 2 kg/cut, then 11
;For force control to be positive zπ, P c −P s≦0
．． 2kg/d, so always l)c
must be reduced to less than 2.2 kg/cnf (1) c≦2.2 kg/C+d). In order to control the pressure within this range, it is necessary to determine the ratio S'/S of the communication passage cross-sectional area S' to the communication passage cross-section 1+IS according to the discharge pressure 1) (1. For example, the discharge pressure I ) (When 1 is relatively high kg/a+t, ', S' /S #7.7 according to item 1 (2).

Also, when the discharge pressure Pd is relatively low at 6 kg/ct+l.

,’, S’ / S #4,4 becomes.

Normally, in order to ensure the responsiveness of the change from the full operating position side to the partially operating operating position side, it is set to S'/S#9 (here, ρ is a predetermined constant).

When the on-off valve 38 is provided as in the present embodiment shown in FIG. 5, and the cross-sectional area of the communication hole 38a is S'',
1) and (2), the following equation holds true.

When the compressor is started or when the load is low, that is, when the discharge pressure is low, the on-off valve 38 is set such that, for example, Pd-Pc=ΔP≦3kg/ct.
Since the valve opens when d, 1, . S'= (2,32-1)S=1.32S...
(5) becomes.

Therefore, the cross-sectional area S" of the communication hole 38a is expressed by the -1-formula (5
), pressure control can be performed reliably by setting the communication passage cross-sectional area S to approximately 1.3 fff.

Next, the operation of the variable capacity vane type j1 compressor having the configuration described above will be explained.

In each compression chamber 12, refrigerant gas is sucked into each compression chamber 12 between the following two vanes in phase 1):) during the suction stroke from the suction chamber II via each suction boat 15 and the notch 25, respectively; The rear vanes in the rotor rotational direction of the two vanes pass through the 1); I side end 25+ of each notch 25, thereby 1); The compression stroke begins when communication with the engine is interrupted. At this compression start time, the control member 24
As the rotation speed increases from the full operating position in Figure 2 to the partially operating position in Figure 3, the discharge capacity decreases continuously. That is, when the control member 24 is in the partially activated position, the front end 25 of each notch 25 of the control member 24
+ is the body of refrigerant gas trapped between the two vanes located at the most 11; +'l is the minimum, the discharge capacity is the minimum, and the control member 24 is in the fully operating position, the 0;j side end 2 of each notch 25
5+ is at the rearmost position in the rotor rotational direction, the compression start time is the earliest, the volume of refrigerant gas trapped between two successive vanes becomes maximum, and the discharge capacity becomes maximum. The control member 24 converts the difference between the resultant force of the suction pressure Ps introduced into the low pressure chamber 231 and the biasing force of the torsion coil spring 35 and the control pressure Pc inside the high pressure chamber 232 into the pressure receiving section 2 .
6, it rotates forward and backward between the full operating position and the partially operating position. That is, when the suction pressure Ps is equal to or higher than a predetermined value, the bellows 3:3px of the on-off valve mechanism 33 contracts and the ball valve body 33c closes the central hole 33, so the on-off valve fitf1t33 is closed. However, the control pressure Pc in the high pressure chamber 232 rises by 2, and the control member 24 rotates toward the full operating position, thereby increasing the discharge volume lit. When the discharge pressure Pd is high, the force with which the plunger 37 pushes the ball valve body 33c becomes large, and the suction pressure Ps (V) is controlled to be low. When the suction pressure Ps becomes below a predetermined value, the bellows 3
3a expands and the ball valve body 33c opens the center hole 33f, so the on-off valve device tI\33 opens, and the control pressure Pc in the high pressure chamber 232 leaks to the suction chamber II side and decreases, causing the control The member 24 partially rotates toward the operating position, thereby reducing the discharge volume. When the discharge pressure Pd is low, the plunger 37
The force that presses the ball valve body 33c becomes smaller, and the suction pressure Ps
The value of is controlled to be high.

When the compressor is started, the pressure receiving part 2 (5) of the control member 24 is at the extreme position on the partially operating side of the pressure working chamber 23, until the discharge pressure Pd reaches a predetermined value, that is, Δ1) (= Pd - Pc ) is less than the predetermined K [(3 kg/cut), the on-off valve 38
The ball valve body 38c is in the open position due to the biasing force of the spring 38d, the on-off valve 38 opens the communication hole 38a, and the discharge pressure 1)d reaches the communication hole 38J! is introduced into the high pressure chamber 232 via. By introducing this discharge pressure lad, especially in the case of this embodiment, the pressure receiving portion 26 smoothly slides toward the fully operating position because the sealing member 27 has a small interference margin and low frictional resistance.

After the compressor is started, when the discharge pressure Pd reaches a predetermined value and enters a steady operating state, the discharge pressure Pd causes the ball valve body 38c to move against the spring 3.
8d to close the communicating hole 38a. As a result, the high discharge pressure that has become equal to or higher than the predetermined value is
is prevented from being introduced into the high pressure chamber 232 and the orifice 2
Normal pressure control is performed using the discharge pressure Pd from only the discharge pressure Pd.

Therefore, at startup, which requires a quick response from the partial plow position to the full plow position, the discharge pressure Pd is introduced from both the orifice 28 and the on-off valve 38, so that the control member can operate smoothly. As the rotation becomes iil function, 0;
When the tightening margin of the seal member 27 is reduced as described above, there is no problem that the control pressure PC in the high pressure chamber 232 does not rise by 11 due to the decrease in sealing performance due to such reduction, and the tl control member is reliably set at all plow positions. It can be moved to the side.

In the above embodiment, the on-off valve 38 was provided in direct communication with the high pressure chamber 232 as shown in FIG. 5, but as shown in FIG.
Communication passage 32 that communicates high pressure chamber 232 and on-off valve mechanism 33
Even if it is provided in , the same effect as described above can be obtained.

(Effects of the Invention) As detailed above, the variable displacement compressor of the present invention opens and closes the valve when the difference between the discharge pressure and the control pressure is small and introduces the discharge pressure into the high pressure chamber of the pressure working chamber. Since the valve is provided, when the compressor is started, the I111 member can be easily rotated from the partially operating position to the fully operating position. J: What about the nails? '7I variable controllability is improved.

[Brief explanation of the drawing]

Figures 1 to 6 show one embodiment of the present invention; Figure 1 is a vertical cross-sectional view of a variable displacement vane compressor taken at an angle of 15 degrees through the axis; is a sectional view taken along the line ■-■ in Fig. 1, showing the state in which the rllJ control member is in the fully operating position, and Fig. 3 is a sectional view similar to Fig. 2, with the control member in the partially operating position. FIG. 4 is a sectional view taken along line IV-IV in FIG. 1, FIG. 6
Figures are similar to Figure 5 and Figure 7 showing an embodiment of the pond of the present invention.
The figure is a schematic diagram of a conventional discharge volume control device. 23...Pressure working chamber, 231...Low pressure chamber, 2:32
...High pressure chamber, 24...Control member, 26...Pressure receiving part, 38...Opening/closing valve, Pd...Discharge pressure, Pc...Control pressure. Fig. 2 25 No. 40 Chi 3 5 Ne 5n 55↑ 5 6 6 C2 Me 7- / 7 □ Pa 33h \ 33f \ 33b 33a

Claims (1)

[Claims] 1. A pressure working chamber provided in a pair of side blocks forming a cylinder and communicating with the low pressure chamber side and the high pressure chamber side, a first chamber communicating the inside of the pressure working chamber with the low pressure chamber side, and the high pressure a second chamber communicating with the chamber side; and a control member having a pressure receiving part slidably fitted in the pressure operating chamber so as to airtightly partition the first chamber and the second chamber. In a variable capacity compressor configured to variably control the discharge capacity by rotating the pressure receiving part of the control member according to the differential pressure to control the compression start timing, the difference between the discharge pressure and the control pressure is A variable displacement compressor, characterized in that it is provided with an on-off valve that opens when the discharge pressure is low and introduces the discharge pressure into the high pressure chamber of the pressure working chamber.