JPH0212313Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a variable compression capacity compressor equipped with a loading/unloading switching mechanism, and more specifically, a variable compression capacity compressor equipped with a load/unload switching mechanism, and more specifically, a pair of front and rear discharge chambers provided facing each other on the front side and the rear side. By providing a loading/unloading switching mechanism in one of the discharge chambers and switching this one discharge chamber between loading and unloading, the compression capacity can be changed in response to changes in the cooling load. This relates to improvement of a compressor installed in a compressor, which is provided at a discharge flange that joins discharge passages extending from both discharge chambers, on the side of the discharge passage communicating with a discharge chamber equipped with a load/unload switching mechanism. The purpose is to obtain a stable open state of the check valve.

For example, in a swash plate compressor, one way to vary the compression capacity without continuing the electromagnetic clutch is to create a pair of front and rear discharge chambers facing each other on the front and rear sides with a swash plate chamber in between. There is a method of providing a loading/unloading switching mechanism in one of the discharge chambers.

FIG. 5 is a drawing showing an example of this, in which a discharge valve 14R for opening and closing the discharge hole 12R is provided in the rear side discharge chamber 18R so as to be able to move toward and away from the rear valve plate 10R. When the cooling load is low, the compressor is biased in a direction away from the rear valve plate, and in such conditions, the compressor as a whole operates at 50% because no compression action is obtained on the rear side. is obtained,
In addition, under high cooling load, a compression action is also exerted on the rear side by feeding discharge pressure into the pressure action chamber 25 and pressing the discharge valve 14R against the rear valve plate 10R through the same discharge pressure. It is designed to ensure 100% operation.

However, in the case of a compressor equipped with a load/unload switching mechanism as described above, a discharge passage 20F extending from both the front and rear discharge chambers 18F, 18R,
At the discharge flange 20 where 20R joins, when the rear discharge chamber 18R is in an unloaded state, the rear side A check valve 30 is provided in the discharge passage 20R, and the head portion 30a of the check valve 30 is
is protruding into the discharge passage 20R, when the rear discharge chamber 18R is in a loaded state and the check valve 30 is open, more specific Specifically, a part of the discharge gas that is pressure-fed through the front-side discharge passage 20F momentarily enters the rear-side discharge passage 20R via the discharge pulsation, and the discharge gas flows through the check valve 30. By acting on the head portion 30a and its upper end surface (the portion facing the lower end portion of the sleeve 31), a downward pressing force is applied to the upper end surface of the head portion 30a, and the check valve 30
Coupled with the weight of the sleeve 31, the upper end surface separates from the lower end of the sleeve 31, creating a slight gap between the two, and at the moment such a slight gap is created, the discharged gas from the front side instantly flows into this gap. and acts as a downward pressing force on the upper end surface of the check valve 30. As the discharged gas from the front side enters the gap in this way, the descending speed of the check valve 30 is accelerated, and the gap further widens.
On the other hand, in the state where the check valve 30 is lowered with a gap between its upper end surface and the lower end of the sleeve 31, the discharge gas pumped from the rear discharge passage 20R is transferred to the check valve 30. By acting on the lower end surface of the head portion 30a, the head portion 30a
An upward pressing force is applied to the lower end surface of the
The check valve 30a is lifted up to a position where it contacts the lower end of the sleeve 31 again. That is, the check valve 30 repeatedly moves up and down continuously in response to the discharge pulsation occurring in the rear side discharge passage R, which causes the check valve 30 to oscillate, making it impossible to obtain a stable open state. At the same time, abnormal noise is generated, and problems such as abnormal wear of the sliding portion of the check valve 30 occur.

The present invention is an attempt to improve the above-mentioned conventional problems, and is designed so that the head part of the check valve can be surrounded from the back side.
By providing a recess for storing the head portion and storing the head portion of the check valve in the recess when the check valve is opened, the check valve may dance and make abnormal noises caused by discharge pulsation. The feature is that it is designed to prevent the occurrence of.

The gist of the present invention is to provide a load/unload switching mechanism in either the front or rear discharge chamber, and to provide a discharge passage extending from both discharge chambers so that the distal ends thereof communicate with each other within the discharge flange. In a swash plate compressor, a check valve is provided in a discharge passage extending from a discharge chamber on a side equipped with a load/unload switching mechanism so as to be openable and closable, facing the discharge gas feeding direction. The structure is such that a storage recess is provided that surrounds the head portion of the check valve from the rear back surface when the valve is opened.

Hereinafter, specific embodiments of the present invention will be described with reference to the illustrative drawings.

1 and 2, reference numeral 1 designates a cylinder block. The cylinder block 1 consists of a front cylinder block 1F and a rear cylinder block 1R.A shaft hole 2' is located in the center of both cylinder blocks 1F and 1R, and a bearing is provided in the coaxial hole 2'. Part 1
The drive shaft 2 is rotatably supported via 6 and 16. An electromagnetic clutch (not shown) is provided at one end of the drive shaft 2, and is connected to and driven by an engine (not shown) by connecting and disconnecting the electromagnetic clutch. Further, an appropriate number of bores 3 are provided on the outer periphery of the shaft hole 2' so as to surround the coaxial hole 2'. Each bore 3 exists between the swash plate chamber 4 and is divided into a pair of front and rear parts, and a double-headed piston 5 is fitted into each bore 3. A swash plate 6 is provided in the swash plate chamber 4 so as to be swingable and rotatable via the drive shaft 2. The piston 5 is anchored to the slope of the swash plate 6 via a ball 7 and a shoe 8, and the rocking rotation of the swash plate 6 is transmitted to each piston 5 as a reciprocating motion. Further, suction passages 9, 9 are provided at the peripheral edges of the cylinder blocks 1F, 1R and also serve as through holes for tightening bolts 23, which will be described later. One end of the suction passages 9, 9 communicates with the swash plate chamber 4, and the other end communicates with the suction chamber 1, which will be described later.
Connects to 7F and 17R. 15F is a front housing that covers the open end of the front cylinder block 1F with the front valve plate 10F in between, and 15R is the rear valve plate 10 as well.
This is a rear housing that covers the open end of the rear cylinder block 1R with R in between, and includes both housings 15F, 15R and both cylinder blocks 1.
F and 1R are integrated through the screwing action of the tightening bolt 23 inserted into the suction passages 9 and 9 described above.
Both housings 15F, 15R have suction chambers 17F, 17R and a discharge chamber 18 corresponding to each bore 3.
F and 18R are provided concentrically with an annular partition between them. That is, the discharge chambers 18F, 18R are located at the center, and the suction chambers 17F, 17R are located near the outer periphery so as to surround the discharge chambers 18F, 18R. Same suction room 17F, 17R
is provided so as to be able to communicate with the swash plate chamber 4 via the suction passages 9, 9 as described above. And front valve plate 10F and rear valve plate 10R
Suction ports 11F, 11R are opened in correspondence with the suction chambers 17F, 17R, and discharge ports 12F, 12R are opened in correspondence with the discharge chambers 18F, 18R, respectively. Further, suction valves 13F and 13R are provided at the suction ports 11F and 11R so as to be located on the bore 3 side and can be opened and closed freely through the suction stroke of the piston 5, and discharge chambers 18F and 18R are provided at the discharge ports 12F and 12R. Discharge valves 14F and 14R are provided on the sides so as to be openable and closable through the exhaust stroke of the piston 5.

And the rear valve plate 10R has connection port 2.
1 is provided. The communication port 21 is connected to the rear valve plate 10R so that it can be covered by the discharge valve 14R.
It is located in the center of the city. Further, a recess 22 is provided in the rear cylinder block 1R in correspondence with the communication port 21. The recess 22 is located at the center of the rear cylinder block 1R. A vent hole 22' is opened at the bottom of the recess 22 and is provided to communicate with the swash plate chamber 4 via the bearing portion 16 of the drive shaft 3.

On the other hand, a spool 24 is provided in the discharge chamber 18R at a position facing the communication port 21 and the recess 22 so as to be able to move forward and backward. A pressure acting chamber 2 is provided between the rear surface of the spool 24 and the inner wall surface of the rear housing 15R.
5 is provided, and the pressure action chamber 25 is provided with a solenoid valve 52,
It is provided so that it can be selectively communicated with a discharge flange and a suction flange, which will be described later, through switching 53.

The solenoid valves 52 and 53 include a sensor mechanism (not shown) that detects changes in the cooling load in the vehicle interior, and a control mechanism 5 that processes signals sent from the sensor mechanism.
The switching effect is obtained via 1. Also, a retainer 26 and a discharge valve 14R are installed on the front side of the spool 24.
is fixed through the screwing of the bolt 27. A spring 28 is interposed between the spool 24 and the recess 22, and the spool 24 is normally biased toward the pressure action chamber 25 by the spring 28. That is, as shown in FIG.
The discharge valve 14R is provided so that it does not come into close contact with the discharge port 12R, in other words, a gap is formed between the discharge port 12R and the discharge valve 14R.

On the other hand, a suction flange connected to a suction pipe (not shown) and a discharge flange 20 connected to a discharge pipe (not shown) are protruded from the outer peripheries of both cylinder blocks 1F and 1R. The suction flange is provided to communicate with the swash plate chamber 4 via the suction passage, while the discharge flange 20 is provided to communicate with the swash plate chamber 4 through the suction passage.
It is provided so as to communicate with both discharge chambers 18F and 18R via.

That is, the discharge flange 20 is provided with a discharge passage 20F communicating with the front discharge chamber 18F, and a discharge passage 20R branching from the discharge passage 20F and communicating with the rear discharge chamber 18R.
A check valve mechanism is provided in R so that it can be opened and closed. The check valve mechanism consists of a valve seat 29, a check valve 30, and a sleeve 31 into which the check valve 30 is inserted.
is provided facing the discharge side (the distal end side of the discharge passage 20R).

The check valve 30 is composed of a head portion 30a and a rod portion 30b, and is provided so as to be movable forward and backward so that the head portion 30a can be brought into contact with the valve seat 29. The sleeve 31 into which the check valve 30 is fitted has an insertion hole 31b for the rod portion 30b, and the sleeve 31 has a housing recess 31a for the head portion 30a at the distal end thereof. It is provided with a storage space that is approximately the same size as the thickness.

In the above embodiment, the storage space of the storage recess 31a is provided with the same dimensions as the thickness of the head portion 30a, but the storage space does not necessarily have to be formed with the same dimensions as the thickness of the head portion 30a. Instead, as shown in FIG. 3, it is also possible to form a storage space that is smaller than the thickness of the head portion 30a. Also, in the above embodiment, the storage recess 31a
is provided on the sleeve 31, but it is also possible to provide it directly on the discharge flange 20 as shown in FIG.

Next, its effect will be explained.

FIG. 1 shows a state in which the compressor is not in operation, and the discharge valve 14R on the rear housing 15R side is in an open state. That is, the spool 24 is urged toward the pressure action chamber 25 by the spring 28, and a gap is formed between the rear valve plate 10R and the discharge valve 14R, in other words, the discharge port 12R
and the communication port 21 are both in an open state,
Between the discharge chamber 18R and the suction chamber 17R are a communication port 21, a recess 22, a through hole 22', a bearing part 16, a swash plate chamber 4,
They are in communication with each other via the suction passage 9. Further, the discharge passage 20R in the discharge flange 20 is closed by a check valve 30.

As described above, the discharge port 12R and the communication port 21 are opened on the rear housing 15R side, the discharge chamber 18R and the suction chamber 17R communicate with each other, and the check valve 30 is operated in a state in which the discharge passage 20R is closed. A state in which the drive shaft 2 is rotated by transmitting the driving force of the engine to the drive shaft 2 through a connecting operation of an electromagnetic clutch (not shown) provided at one end of the shaft 2, and a state where the drive shaft 2 is rotated through the rotation of the drive shaft 2. A state in which the swash plate 6 swings and rotates within the swash plate chamber 4 is obtained. Since each piston 5 is moored to the swash plate 6 via the shoe 8 and the ball 7, the swinging rotation of the swash plate 6 is controlled by the shoe 8 and the ball 7.
A state in which each piston 5 continuously reciprocates within each bore 3 is obtained.

On the other hand, the refrigerant gas sent into the compressor via the evaporator and the suction pipe is sent from the suction flange through the swash plate chamber 4 and the suction passage 9 into the suction chambers 17F and 17R. and front housing 15
The refrigerant gas sent into the F-side suction chamber 17F forcibly pushes open the suction valve 13F through the negative pressure generated in the bore 3 during the suction stroke of each piston 5, and is sucked into the bore 3 through the suction port 11F. while being compressed through the exhaust stroke of each piston 5,
Through this compression action, the discharge valve 14F is forcibly opened and sent into the discharge chamber 18F from the discharge port 12F, that is, a compression action is obtained, but the refrigerant is sent into the suction chamber 17R on the rear housing 15R side. For gas, the discharge port 12R is in an open state, and the discharge chamber 18R is connected to the communication port 2 as described above.
1. Since it is in communication with the suction chamber 17R through the recess 22, the bearing part 16, the swash plate chamber 4, and the suction passage 99, a negative pressure state does not occur in the bore 3 during the suction stroke of the piston 5. . Therefore, no compression effect can be obtained. That is, at the start of operation, compression action is obtained only on the front housing 15F side (50% operating state).

The refrigerant gas thus compressed on the front side is sent into the discharge pipe through the discharge passage 20F, and a portion of the refrigerant gas is sent into the pressure action chamber 25. By feeding the refrigerant gas (discharge pressure) into the pressure action chamber 25 in this manner, the pressure within the pressure action chamber 25 is increased.

When this pressure exceeds the pressure of the spring 28, the spool 24 overcomes the biasing pressure of the spring 28 and moves toward the rear valve plate 10R, as shown in FIG.
is in close contact with the rear valve plate 10R, more specifically, the discharge port 12R is closed by the discharge valve 14R.
A state in which the communication port 21 is closed is obtained. Since the discharge valve 14R closes the discharge port 12R and the communication port 21 in this manner, the refrigerant gas can be compressed on the rear housing 15R side as well. In other words, 100% operating status can be obtained.

Since the compression action is obtained on the rear side in this way, the refrigerant gas pumped through the discharge passage 20R is discharged onto the surface of the head portion 30a of the check valve 30 (the surface facing the valve seat 29) at the discharge flange 20. Pressure is applied, and the head portion 30a is pushed back toward the sleeve 31 by the discharge pressure to open the discharge passage 20R. More specifically, the check valve 30 is pushed back into the sleeve 31 so that its head portion 30a is inserted into the storage recess 31a.

In this manner, when the 100% operating state is obtained and the check valve 30 opens the rear discharge passage 20R, both the front and rear discharge chambers 18
The discharge gases fed under pressure from F and 18R join together at the same discharge flange 20, but discharge pulsation occurs because they are discharged sequentially from a plurality of bores. However, the pressure drop due to this discharge pulsation is instantaneous, and there is a pressure difference of about 10% at most, and this pressure drop is due to the discharge gas being pressure-fed through the front side discharge passage 20F. A part of the pressure enters the discharge passage 20R side due to the differential pressure, and the pressure is supplemented, so that the drop in pressure that the surface of the head portion 30a of the check valve 30 (the surface facing the valve seat 29) receives is almost negligible. do not have. Furthermore, pressure fluctuations due to discharge pulsation also act on the rod portion 30b of the check valve 30 that protrudes into the discharge passage of the discharge flange 20, and the end surface of the rod portion 30b is smaller than the end surface of the head portion 30a. Since the area that receives the pressure is extremely small, only an extremely small pressure is applied to the rod portion 30b side compared to the head portion 30a side.
The pressure is not strong enough to push out the container from the storage recess 31a. In this way, the head portion 30 of the check valve 30
A constant pressure is applied to the surface a, and the head portion 30a of the check valve 30 is inserted into the storage recess 31a, so that the discharge passage 20R is fully opened without being affected by the discharge pulsation. It is possible to maintain the state of

In this state where 100% operation is obtained, the cooling load in the vehicle compartment decreases, and when the sensor mechanism detects the decrease in the cooling load, the solenoid valves 52 and 53 are switched to reduce the pressure. The action chamber 25 contains refrigerant gas (suction pressure) in the suction flange.
In this way, suction pressure is sent to the pressure action chamber 25 and the pressure in the pressure action chamber 25 decreases,
The biasing pressure of the spring 28 is overcome and the rear discharge valve 1
4R is opened and the rear side becomes unloaded. In this way, when the rear side becomes unloaded, the differential pressure generated between the rear side discharge passage 20R and the front side discharge passage 20F increases, and the front side discharge pressure flows into the rear side discharge passage 20R. The state is obtained. In this way, the discharge flow flowing into the rear side discharge passage 20R (discharge passage 20R
(reverse flow occurs) against the surface of the head portion 30a of the check valve 30 (the surface facing the valve seat 29).
It acts as a dynamic pressure toward the valve seat 29 and serves to pull the head portion 30a downward. or,
Since the rear side discharge gas that had been acting to push up the head section 30a until the unloading state is no longer present, this, together with the discharge flow that acts to pull the head section 30a downward as described above,
While the check valve 30 quickly descends due to its own weight, when the head portion 30a descends and protrudes from the storage recess 31a, the back side of the head portion 30a (the contact with the storage recess 31a) By applying the pressure from the discharge flow downward to the opposing surface, the check valve 30 descends at an even faster speed, thereby ensuring that the discharge passage 20R is connected to the check valve 30. It becomes obstructed. (The effect of switching from 100% operation to 50% operation can be obtained.) The present invention is constructed as described above.
As mentioned above, in correspondence with the head part of the check valve,
By providing a storage recess for the head portion and storing the head portion in the recess when the check valve is opened, it is possible to prevent the check valve from swinging due to discharge pulsation. It has become possible to maintain the open state and prevent the occurrence of abnormal noise and abnormal wear. In other words, it has become possible to obtain a highly reliable open state of the check valve. Although the above embodiment describes an example in which the present invention is applied to a swash plate compressor, the present invention can also be applied to a check valve provided in a portion of a crank type reciprocating compressor where two discharge chambers communicate with each other through a discharge passage. .

[Brief explanation of drawings]

Figure 1 is a side sectional view of the compressor according to the present invention, Figure 2 is a side sectional view of the compressor according to the present invention;
The figure is a side sectional view showing the same operating state, Figures 3 and 4.
The figure is a cross-sectional view of a discharge flange portion showing another embodiment, and FIG. 5 is a side cross-sectional view of a compressor showing a conventional structure. 1...Cylinder block, 1F...Front cylinder block, 1R...Rear cylinder block, 2...Drive shaft, 2'...Shaft hole, 3...Bore, 4...Swash plate chamber, 5...Piston, 6 ...Swash plate, 7...Ball, 8...Show, 9...Suction passage, 10F...Front valve plate, 10R
...Rear valve plate, 11F, 11R...Suction port, 12F, 12R...Discharge port, 13F, 13
R...Suction valve, 14F, 14R...Discharge valve, 15
F...Front housing, 15R...Rear housing, 16...Bearing part, 17F, 17R...
Suction chamber, 18F, 18R...Discharge chamber, 20...Discharge flange, 20F, 20R...Discharge passage, 21
...connection port, 22 ... recess, 22' ... ventilation hole,
23...Tightening bolt, 24...Spool, 25
...Pressure action chamber, 26...Retainer, 27...
Bolt, 28... Spring, 29... Valve seat, 30...
Check valve, 30a...Head part, 30b...Rod part, 31...Sleeve, 31a...Storage recess, 3
1b...Insertion hole, 51...Control mechanism, 52, 53
……solenoid valve.

Claims (1)

[Scope of utility model registration request] A load/unload switching mechanism is provided in either the front side or the rear side discharge chamber, and the tips of the discharge passages extending from both discharge chambers are provided so as to communicate within the discharge flange, and the load/unload switching mechanism is provided. A check valve that opens and closes the discharge passage according to the discharge gas pressure is provided in the discharge passage extending from the discharge chamber on the side provided with the discharge gas, so as to be movable in the vertical direction and opposite to the feeding direction of the discharge gas. A compressor comprising: a storage recess that surrounds the head portion of the check valve from the rear back surface when the check valve is opened, and is opened downward in the check valve holding portion of the discharge passage. A discharge passage opening/closing mechanism in a compressor.