JPH055269Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a scroll compressor with a capacity control mechanism that is widely used for compressing refrigerant in air conditioners and the like.

(Prior art) Conventionally, this type of compressor has been developed, for example, in JP-A-61-
291792, and as shown in FIG. 7, fixed and movable scrolls X,
Y are combined and installed in a facing manner, and each spiral body a, b
A pair of bypass holes M, M are opened in the middle part of the compression stroke in the two systems of compression chambers A, B formed between them, and by opening the bypass valves V, V installed individually on the upper surface of the fixed scroll X, The fluid in the middle of compression is bypassed to the suction port L side via the bypass passages R, R defined on the outer circumference of the upper surface of the fixed scroll X and inside the casing K. In addition to operation at full capacity, low capacity Partial capacity operation is possible.

In addition, in the case where the capacity can be controlled in this way,
In order to improve efficiency during partial capacity operation, a discharge valve HV is provided on the outlet side of the discharge hole H, which opens when the internal pressure of the innermost compression chamber AB rises to a predetermined level.

(Problem to be solved by the invention) However, if the discharge valve HV is provided, the discharge valve HV will repeatedly open and close following changes in the internal pressure of the innermost compression chamber AB. There was a problem in that the opening and closing caused operational noise, which caused unpleasant noises.

Moreover, due to the intervention of the discharge valve HV, the flow velocity of the fluid discharged from the discharge hole H is increased, and the discharge valve
The jetting noise when passing through the HV also becomes louder, further raising the noise level.Also, since the compressed fluid is intermittently discharged by opening and closing the discharge valve HV, the discharge pulsation is also large. It turned out to be so.

Furthermore, as a bypass mechanism, bypass valves V, V are individually installed on the upper surface of the fixed scroll X, and bypass passages R, R are also defined between the outer periphery of the upper surface of the fixed scroll Because of this, there are problems with poor airtightness and a complicated configuration.

Furthermore, in Japanese Patent Application Laid-Open No. 58-101287, it appears that the structure between the fixed scroll and the casing has been slightly devised, and the support of the bypass valve and the structure of the bypass passage have been somewhat relaxed. However, since it is necessary to define a passage or a chamber between the fixed scroll and the casing, which is an outer frame member, there are still problems in that the airtightness is poor, the structure is complicated, and the workability and assemblage are poor.

Furthermore, it is known that a noise-reducing muffler is provided in the discharge part, as disclosed in Japanese Utility Model Application Publication No. 61-48991, but it is large enough to cover the entire fixed scroll, and there is a problem that it cannot be immediately applied to a device with a bypass mechanism. There is.

The purpose of the present invention is to reduce valve noise, discharge jet noise, and discharge pulsation in a device having a bypass mechanism, and to configure the noise reduction mechanism and bypass mechanism to be compact and easy to process and assemble. The object of the present invention is to provide a scroll compressor that can simplify the structure as a whole, reduce leakage, and improve reliability.

(Means for Solving the Problems) Therefore, in the present invention, a fixed scroll 2 and a movable scroll 3 are housed in a casing 1 in a facing combination, and on the upper surface of the fixed scroll 2,
A discharge chamber 16 is defined for releasing the fluid taken into the compression chamber from the spiral outer region of each of the scrolls 2 and 3 to be compressed, and a discharge valve 13 is provided in the discharge hole 12 opening in the spiral center of the fixed scroll 2. while the fixed scroll 2
In a scroll compressor provided with a pair of bypass holes 6A and 6B that open into a compression chamber in the middle of a compression stroke, each of the bypass holes 6A and 6B is provided in a portion outside the spiral of the fixed scroll 2, and a suction communication hole 7A is provided. , 7B, a pair of internal valve holes 62A, 62B of the unloader pistons 9A, 9B that open and close the bypass passages 8A, 8B, and a small room that covers the discharge valve 13. An unloader valve block 60 is formed which is integrally provided with a muffler 61 whose interior is communicated with the discharge chamber 16 through a communication hole 64 provided in a partition wall.
was attached to the upper surface of the fixed scroll 2.

(Function) The muffler 61 integrated into the unloader valve block 60 can reduce valve noise, discharge jet noise, and discharge pulsation. Moreover, in addition to such a silencing effect, the valve block 60
In addition, since the bypass passages 8A, 8B, the piston internal valve holes 62A, 62B, and the muffler 61 are integrated, the structure can be made smaller, and only the valve block 60 needs to be processed. In addition, during processing, the valve block 60
It is sufficient to consider the airtightness of each part of the fixed scroll 2 and the airtightness of the part attached to the top surface of the fixed scroll 2, so the processability can be improved.Moreover, the valve block 60 can be attached to the top surface of the fixed scroll 2 with just one touch. The bypass mechanism and the muffling mechanism can be configured with
This makes it possible to reduce leakage and improve reliability.

(Embodiment) The one shown in FIG. 1 includes a fixed scroll 2 in which a spiral body 22 that conforms to an involute shape is protruded from an end plate 21 through a frame 10 in a closed casing 1, and an end plate 31 An eccentric rotating part is provided with a counterweight 51 and a swing link 52 driven by a drive shaft 40 of a motor 4. 5 and
The movable scroll 3 is driven to revolve around the fixed scroll 2 via the Oldham ring 53 constituting an anti-rotation mechanism, and the suction fluid taken in from the suction ports 11 and 11 is transferred to the two formed between the spiral bodies 22 and 32. Compressed fluid is compressed in compression chambers A and B of the system, and the compressed fluid is discharged from a discharge hole 12 via a discharge valve 13.

As clearly shown in FIG. 3, the end plate 21 of the fixed scroll 2 is provided with a pair of bypass holes 6 each opening into the compression chambers A and B during the compression stroke.
A, 6B, and a pair of suction communication holes 7A, 7B communicating with the suction ports 11, 11 are formed.

The bypass holes 6A and 6B are connected to the spiral bodies 22 and 3.
A pair of sliding contacts PA and PB along the tangential direction of 2 simultaneously pass through the holes 6A and 6B, and the pressure is balanced between the two compression chambers A and B secured on the inner circumferential side from the passing point. establish. In this case, since the center of the base circle 22a forming the involute of the spiral body 22 is generally placed at the center O of the fixed scroll 2, the two bypass holes 6A and 6B are opened at asymmetric positions with respect to the center O. That will happen. In FIG. 3, the white arrows indicate the directions in which the sliding contacts PA and PB move as the movable scroll 2 rotates.

A pair of bypass passages 8A, 8B which communicate the bypass holes 6A, 6B with the suction communication holes 7A, 7B, respectively, and the bypass passages 8A, 8B.
A pair of unloader pistons 9A, 9A that open and close the
An unloader valve block 60 is formed.

As clearly shown in FIGS. 4 and 5, this valve block 60 is connected to the bypass passages 8A, 8B,
It is composed of a port cover 63 in which valve holes 62A and 62B are formed in which the pistons 9A and 9B are slidably inserted, a thin plate-shaped gasket 66 interposed on the upper surface of the cover 63, and an upper lid 67. The discharge valve 13 is located in the center of the port cover 63 constituting the valve block 60.
A muffler 61 for silencing fluid discharged from the discharge hole 12 is integrally formed.

The discharge valve 13 is connected to the seating seat 1 having a planar annular shape.
3a, a disc spring 19 that constantly applies a biasing force to the seated side of the seat 13a, and a pair of upper and lower valve retainers 1.
It constitutes a discharge valve module 15 that is integrated with the valve 4 and the like. The entire integrated discharge valve module 15 is housed in the muffler 61.

The muffler 61 communicates with a discharge chamber 16 defined on the upper surface side of the fixed scroll 2 via a communication hole 64, and the discharge chamber 16 is connected to an external discharge pipe 17.

Further, the pair of bypass passages 8A, 8B and the valve holes 62A, 62B provided in the port cover 63 are arranged symmetrically with respect to the center of the muffler 61 and, in turn, the center O of the valve block 60.

As shown in FIG. 6, the gasket 66 interposed on the upper surface of the port cover 63 has an elongated hole 65 in the center in the longitudinal direction, and is formed by compressing a material such as asbestos into a thin plate shape. , port cover 6
3 and the upper lid 67 in the shape of a sandwich.

Further, in the center of the upper lid 67, there is a control pressure introduction pipe 68 that can be selectively switched between the high pressure side and the low pressure side.
and connect the valve hole 6 through the gap of the extraction hole 65.
The control pressure is guided to the back pressure chambers 69A, 69B of the pistons 9A, 9B in the pistons 2A, 62B.

The unloader pistons 9A, 9B have a valve main body 90 having a large diameter portion 91 and a small diameter portion 92.
It is of a so-called poppet type in which a valve seat 93 made of resin or the like is integrated with a caulking pin 94. Each back pressure chamber 69A,
69B side and the bypass passages 8A, 8B side, and each piston 9A, 9B is connected to the bypass hole 6A, 6B at the stepped portion 96 between the large diameter portion 91 and the small diameter portion 92. Coil springs 18 that urge the opening direction are brought into contact with each other.

As shown in FIG.
It is bolted to the upper surface of the end plate 21 in accordance with the figure.

On the other hand, the bypass hole 6 in the fixed scroll 2
Around A, 6B, seat holes 2A, 2B having a larger diameter than the bypass holes 6A, 6B are provided symmetrically with respect to the center O, and each valve of the pistons 9A, 9B is provided in the seat holes 2A, 2B. Valve seat 4 on which seat 93 is seated
A, 4B are formed to absorb the axial misalignment between the pistons 9A, 9B, which are arranged symmetrically about the center O, and the bypass holes 6A, 6B, which are arranged asymmetrically about the same center O. .

With the above configuration, when high pressure is introduced into each back pressure chamber 69A, 69B from the introduction pipe 68, each piston 9A, 9B moves against the spring 18, and its seat portion 93 is placed on the valve seat 4A, 4B. When seated, the bypass holes 6A and 6B are closed, communication from the bypass holes 6A and 6B to the suction side is cut off, and compression is performed in the entire range from the suction port 11 to the discharge hole 12, so that compression is performed at the full capacity. The driver is responsible for driving the vehicle.

On the other hand, when each back pressure chamber 69A, 69B is opened to the low pressure side, each piston 9A, 9B is moved by a spring 18.
By returning the bypass holes 6A and 6B to the suction port 11 side and bypassing the intermediate pressure fluid in the middle of the compression stroke to the suction side,
It performs low-capacity, partial-capacity operation.

During this partial capacity operation, the bypass holes 6A, 6
The area from B to the discharge hole 12 is the area where a substantial compression stroke takes place, and the pressure in the innermost compressor chamber AB is lower than that during full capacity operation, but the discharge valve 13 intervenes, Since the discharge is performed after the internal pressure of the innermost compression chamber AB has increased to a predetermined level or higher, the compression efficiency can be increased.

The noise muffler 61 integrated with the unloader valve block 60 can reduce the operating noise of the discharge valve 13 and also reduce the jetting noise of the discharge fluid discharged from the discharge hole 12, thereby suppressing the noise level.

Further, the discharge fluid that is intermittently discharged by opening and closing the discharge valve 13 is temporarily stored in the space inside the muffler 61 and then flows through the communication hole 64 to the discharge chamber 1.
6 and is discharged from the external discharge chamber 17, and due to the cushioning effect of the two stages of the muffler 61 and the discharge chamber 17, the discharge pulsation can be further reduced.

Moreover, in addition to such a silencing effect, the valve block 60 has bypass passages 8A, 8B,
Since the piston internal valve holes 62A, 62B and the muffler 61 are integrated, the structure can be made smaller, and only the valve block 60 needs to be processed.
Since it is sufficient to consider the airtightness of each part of the valve block 60 and the airtightness of the part attached to the upper surface of the fixed scroll 2, its workability can be improved, and the valve block 60 can be attached to the upper surface of the fixed scroll 2 with one touch. The bypass mechanism and the muffling mechanism can be configured by simply attaching the casing, and the overall configuration can be simplified, while leakage can be reduced and reliability can be improved.

Further, as a structure for introducing the control pressure of the unloader pistons 9A and 9B, a gasket 66 having a vent hole 65 is interposed in the shape of a sanderch between the upper surface of the port cover 63 constituting the valve block 60 and the upper lid 67. The control pressure introduced from one introduction pipe 68 is released into the gap of this vent hole 65, and is led from the gap of the vent hole 65 to each back pressure chamber 62A, 62B, so that the control pressure can be introduced as a structure. It is strong and simple, and its reliability and ease of assembly can be improved.

Moreover, at this time, since the connection position of the introduction pipe 68 is made to coincide with the center of the upper lid 67, that is, the center of the casing 1, and the rotation center of the drive shaft 4, etc., the introduction pipe 68 is Stress concentration can also be alleviated, and damage to the introduction tube 68 can be reliably prevented.

(Effect of the invention) As described above, in the present invention, the unloader valve block 60
The muffler 61 integrated into the valve block 60 not only reduces valve noise, discharge jet noise, and discharge pulsation, but also includes bypass passages 8A and 8 in the valve block 60.
B. Since the piston interior valve holes 62A, 62B, and the muffler 61 are integrated, the structure can be made smaller, and only the valve block 60 needs to be processed. , it is sufficient to consider the airtightness of each part of the valve block 60 and the airtightness of the attachment part to the upper surface of the fixed scroll 2, so that its workability can be improved.
By simply attaching the valve block 60 to the upper surface of the fixed scroll 2 with a single touch, a bypass mechanism and a silencing mechanism can be configured, and the overall configuration can be simplified while reducing leakage and improving reliability. It is possible.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a scroll compressor according to the present invention, Fig. 2 is a plan view thereof in the direction of arrows, Fig. 3 is an enlarged sectional view of the main part from the same, and Fig. 4 is a view of the area around the unloader valve block. 5 is a bottom view of the valve block, FIG. 6 is a plan view of a gasket which is a part of the valve block, and FIG. 7 is a longitudinal sectional view of a conventional example. 1...Casing, 2...Fixed scroll, 3
...Movable scroll, 12...Discharge hole, 13...
Discharge valve, 6A, 6B...Bypass hole, 8A, 8B
... Bypass passage, 9A, 9B ... Unloader piston, 21, 31 ... End plate, 22, 32 ... Spiral body, A, B ... Compression chamber, 60 ... Unloader valve block, 61 ... Silence muffler, 16 ...Discharge chamber, 64...Communication hole, 7A, 7B...Suction communication hole, 62A, 62B...Valve hole.

Claims (1)

[Scope of utility model registration request] A fixed scroll 2 and a movable scroll 3 are housed in a casing 1 in opposition to each other, and each scroll 2,
A discharge chamber 16 is defined for releasing the fluid taken into the compression chamber from the outer region of the spiral 3 to be compressed, and a discharge valve 13 is attached to the discharge hole 12 opening at the center of the spiral of the fixed scroll 2, A pair of bypass holes 6A, 6 are provided in the fixed scroll 2, which open into the compression chamber during the compression stroke.
B, a pair of bypass passages 8A, 8B that connect the bypass holes 6A, 6B to suction communication holes 7A, 7B provided in the spiral outer portion of the fixed scroll 2, and the bypass passages. Internal valve holes 62A, 62 of a pair of unloader pistons 9A, 9B that open and close 8A, 8B
An unloader valve block 60 is integrally provided with a muffler 61 that divides a small chamber that covers the discharge valve 13 and communicates with the discharge chamber 16 through a communication hole 64 provided in the partition wall. A scroll compressor characterized in that this valve block 60 is attached to the upper surface of the fixed scroll 2.