JPH04179886A - Scroll type compressor - Google Patents

Abstract

PURPOSE:To reduce the number of parts and the manday for assembling and processing by boring by-pass ports in an end plate of a fixed scroll, and engaging a capacity control block having a by-pass route and a valve mechanism built-in with the fixed scroll. CONSTITUTION:A pair of by-pass ports 33a and 33b are bored in an end plate 11 of a fixed scroll 10 so as to communicate with compression chambers 19a and 19b. A capacity control block 50 is arranged so as to be stuck fast to the outside surface of the end plate 11 of the fixed scroll 10, and an engaging recess part 51 is engaged with an engaging projection part 10a arranged in the fixed scroll 10 so as to be arranged fixedly in a housing 1. A discharge hole 53 to communicate with a discharge port 29 is bored in the central part of the capacity control block 50, and the discharge hole 53 is opened/closed by means of a discharge valve 30 fastened with bolts to the outside surface of the control block 50 together with a retainer 35. Thereby, processing of the fixed scroll and the capacity control block can be made easily, and its cost can be reduced significantly, and the capacity control block can be also integrated into the housing easily.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a scroll compressor suitable for use in vehicle air conditioners and the like.

(Prior Art) An example of a conventional scroll compressor is shown in Figs. 8 to 10.
As shown in the figure.

In FIG. 8, 1 is a closed housing, which is connected to a cup-shaped main body 2 and fastened thereto by a bolt 3. In FIG. It consists of a plate 4 and a cylindrical member 6 fastened to the plate with bolts 5. A main shaft 7 passing through the cylindrical member 6 is rotatably supported by the housing l via bearings 8 and 9.

A fixed scroll 10 is disposed within the housing 1. The fixed scroll 10 includes an end plate 11 and a spiral wrap 12 erected on the inner surface of the end plate 11. The fixed scroll 10 is fixedly installed within the housing 1 by being fastened to the housing 1. By bringing the outer peripheral surface of the end plate 11 into close contact with the inner peripheral surface of the cup-shaped main body 2, the inside of the pufferfish 1 is partitioned,
A discharge cavity 31 is formed on the outside of the end plate 11, and a suction chamber 28 is defined on the inside of the end plate 11.

Further, a discharge port 29 is bored in the center of the end plate 11,
This discharge boat 29 is opened and closed by a discharge valve 3° which is fastened together with a retainer 35 to the outer surface of the end plate 11 by bolts 36.

The orbiting scroll 14 includes an end plate 15 and a spiral wrap 16 erected on the inner surface of the end plate 15.
has substantially the same shape as the spiral wrap 12 of the fixed scroll 10.

The orbiting scroll 14 and the fixed scroll 10 are eccentric to each other by the radius of revolution and angularly shifted by 180'', and are engaged with each other as shown.

Thus, the chimp seal 17 embedded in the tip surface of the spiral wrap 12 is in close contact with the inner surface of the end plate 15, and the chimp seal 18 embedded in the tip surface of the spiral wrap 16 is in close contact with the inner surface of the end plate 11. As shown in FIG. 10, the side surfaces of the spiral wraps 12 and 16 have a plurality of compression chambers 19a, 19b that are closely spaced at points a, b, c, and d and are approximately symmetrical with respect to the center of the spiral. is formed.

A drive bushing 21 is rotatably fitted inside a cylindrical post 20 protruding from the center of the outer surface of the end plate 15 via a bearing 23, and an eccentric hole 24 bored in the drive bushing 21. An eccentric pin 25, which is eccentrically protruded from the inner end of the main shaft 7, is rotatably fitted inside. A balance weight 27 is attached to this drive bush 21.

A rotation prevention mechanism 26 that also serves as a thrust bearing is provided between the outer peripheral edge of the outer surface of the end plate 15 and the inner surface of the front end plate 4.
is located.

When the main shaft 7 is rotated, the orbiting scroll 14 is driven via the orbiting drive mechanism consisting of the eccentric pin 25, the drive bush 21, the boss 20, etc., and the orbiting scroll 14 is prevented from rotating by the rotation prevention mechanism 26. While being rotated, it revolves around a circular orbit having a radius of revolution, that is, the amount of eccentricity between the main shaft 7 and the eccentric pin 25. Then, the line contact part a % d between the spiral wraps 12 and 16 gradually moves toward the center of the spiral, and as a result, the compression chamber 1
9a and 19b move toward the center of the thin winding while decreasing their volume.

Along with this, gas flowing into the suction chamber 28 through an inlet (not shown) is taken into each compression chamber 19a, 19b from the outer end openings of the spiral wraps 12 and 16, and is compressed while being compressed into the central portion. From here, it passes through the discharge boat 29, pushes open the discharge valve 30, and is discharged into the discharge cavity 31, from where it flows out through a discharge port (not shown).

Inside the end plate 11 of the fixed scroll IO, there are
As shown in Figure 0, a pair of cylinders 32a and 32b are bored, one end of which communicates with the suction chamber 28, and these pair of cylinders 32a and 32b are located on both sides of the discharge boat 29 and extend parallel to each other. . Also, this end plate 1
1 is provided with bypass ports 33a and 33b for bypassing the gas that is being compressed from the pair of compression chambers 19a and 19b to the cylinders 32a and 32b. Pistons 34a and 34b for opening and closing the bypass ports 33a and 33b are fitted into these cylinders 32a and 32b in a sealed and slidable manner.

However, when the compressor is operating at full load, the piston 3
A control valve 38 is provided on each inner end surface of 4a and 34b.
The high-pressure control gas generated in The bypass ports 33a, 33b are closed by advancing against the force.

On the other hand, during unload operation of the compressor, the pressure of the control gas generated from the control valve 38 is reduced. Then, each piston 34a, 34b is released by the return spring 41a.
, 41b retreats and occupies the position shown in the figure, and the gas that is being compressed from the pair of compression chambers 19a, 19b passes through the bypass ports (33a, 33b) and reaches the piston 3.
Communication holes 42a, 42b bored in 4a, 34b,
Blind holes 43a, 43b, cylinders 32a, 32
It flows out into the suction chamber 28 through b.

(Problems to be Solved by the Invention) In the above-mentioned conventional compressor, the compression chambers 19a and 19b are formed point-symmetrically with respect to the center of the spiral, so that gas in the middle of compression is released from these compression chambers 19a and 19b, respectively. In order to bypass the
, 32b, and these pair of cylinders 3
Pistons 34a and 3 are located in 2a and 32b, respectively.
4b.

Return springs 41a, 41b, spring receivers 40a, 4
Since it is necessary to provide two sets of 0b, etc., the structure becomes complicated, and there is a problem that the number of parts, assembly, and processing steps increase, as well as cost and weight.

(Means for Solving the Problems) The present invention was invented to solve the above problems, and its gist is that a fixed scroll comprising spiral lamps erected on each end plate. and an orbiting scroll are engaged with each other at different angles to form a compression chamber, the fixed scroll is fixedly installed in the housing, and the orbiting scroll is rotated by an orbit drive mechanism while being prevented from rotating by an rotation prevention mechanism. By rotating the compression chamber, the gas is compressed by moving it toward the center of the spiral without losing its volume, and the compressed gas is discharged into the housing through a discharge port provided on the end plate of the fixed scroll. In a scroll type compressor that discharges into a discharge cavity formed in the housing, a bypass port communicating with the compression chamber is bored in the end plate of the fixed scroll, and this bypass port is communicated with a suction chamber formed in the housing. A capacity control block incorporating a bypass passage that communicates and a valve mechanism that opens and closes this passage is configured separately from the fixed scroll, and this capacity control block is fitted with the fixed scroll and fixedly installed in the housing. The scroll type compressor is characterized by:

(Function) Since the present invention has the above configuration, the capacity control block is fitted to the fixed scroll and fixedly installed in the housing, so that the bypass port communicating with the compression chamber is provided in the capacity control block. It is connected to the suction chamber in the housing via a bypass passage, and the capacity of the compressor is controlled by opening and closing this bypass passage by the pulp.

Embodiment One embodiment of the present invention is shown in FIGS. 1-7.

Compression chambers 19a, 19 are provided in the end plate 11 of the fixed scroll 10.
A pair of bypass ports 33a and 33b communicating with b are bored. A capacity control block 5o is arranged so as to be in close contact with the outer surface of the end plate 11 of the fixed scroll 1o, and this capacity control block 50 has a fitting recess 51 provided therein.
is fitted into the fitting convex portion 10a provided on the fixed scroll 10, the hole 3 is passed through the bolt hole 52 drilled in the capacity control block 50, and its tip is attached to the fixed scroll 10.
It is fixedly installed in the housing 1 by screwing into the housing 1.

By bringing the rear outer peripheral surface of the capacity control block 50 into close contact with the inner peripheral surface of the cup-shaped main body 2 in a sealed manner, the inside of the housing 1 is partitioned into a suction chamber 28 and a discharge cavity 31.

A discharge hole 53 communicating with the discharge port 29 is bored in the center of the capacity control block 50, and the discharge hole 53 is opened and closed by a discharge valve 30 fastened to the outer surface of the control block 50 together with a retainer 35 with a bolt 36. It is now possible to do so.

A cylinder 54 in the form of a blind hole is bored on one side of the discharge hole 53, and a cavity 55 in the form of a blind hole is bored in parallel with the cylinder 54 on the other side. are in communication with the suction chamber 28, respectively.

A convex-shaped piston 56 is built into the cylinder 54 in a sealed and slidable manner, and a control pressure chamber 8 is provided on one side of the piston 56.
A chamber 81 bounded by 0 and bounded on the other side communicates with the suction chamber 28 . The piston 56 is pushed toward the control pressure chamber 80 by a coil spring 83 interposed between the piston 56 and the spring receiver 82 . An annular groove 93 formed in the outer peripheral surface of the piston 56 is always in communication with the chamber 81 through a plurality of holes 94.

On the other hand, a control pulp 58 is fitted in the cavity 55, and by partitioning the gap between the cavity 55 and the control pulp 58 with O-rings 59, 60, 61, 62, an atmospheric pressure chamber 63, a low pressure chamber 64, Control pressure chamber 65 and high pressure chamber 66 are limited. The atmospheric pressure chamber 63 is connected to the through hole 6
7 and the atmosphere outside the housing 1 via a pressure impulse pipe (not shown). The low pressure chamber 64 communicates with the suction chamber 28 through the through hole 68, the control pressure chamber 65 communicates with the control pressure chamber 80 through the through hole 69, the groove 70, and the through hole 71, and the high pressure chamber 66 communicates with the suction chamber 28 through the through hole 68. It communicates with the discharge cavity 31 via 72.

Thus, the control valve 58 is connected to the discharge cavity 3.
The high pressure BP in the suction chamber 28 and the low pressure LP in the suction chamber 28 are sensed, and a corresponding 1III pressure ^P is generated.

As shown in FIG. 7, grooves 70, 90, 91, a first recess 86, a second recess 87, and a third recess 88 are bored in the inner surface of the capacity control block 50. . The first of these,
Land portion 57 surrounding second and third recesses 86, 87, 88
A sealing material 85 fitted into a sealing groove 84 bored in the
These first, second, and third recesses 86, 87, .
88 is formed between the capacity control block 50 and the outer surface of the end plate 11, and is partitioned from each other by the sealing material 85. The first recess 86 communicates with the control pressure chambers 65 and 80 via the groove 70 and the through hole 69.71, and the second recess 87
are a pair of bypass ports 33a bored in the end plate 11.
, 33b to the compression chambers 19a, 19 during compression.
The third recess 88 communicates with the discharge hole 53 through the groove 90.91 and through the communication hole 92. It communicates with the chamber 81 of the cylinder 54.

Note that the bypass ports 33a and 33b are the compression chambers 19.
The compression chambers 19a and 19b remain in the compression chambers 19a and 19b until they enter the compression stroke and their volumes are reduced to 50% after they finish inhaling the gas.
9b.

The rest of the structure is the same as the conventional one shown in FIGS. 8 to 10, and corresponding members are given the same reference numerals.

Therefore, during the unload operation of the compressor, the control pressure AP generated by the control valve 58 decreases. When this control pressure AP is introduced into the control pressure chamber 80 through the through hole 69, groove 70, and through hole 71, the piston 56 is pushed by the restoring force of the coil spring 83 and assumes the position shown in FIG. . In this way, the communication holes 89a, 89b and the communication hole 92 are opened, so that the gas being compressed in the compression chambers 19a, 19b passes through the bypass ports 33a, 33b, the second recess 87, and the communication holes 89a, 89b. The gas in the compression chamber that entered the chamber 81 and reached the center of the spiral, that is, the compressed gas, flows through the discharge port 29, the discharge hole 53, the third recess 88, the groove 90, 91, and the communication hole. 92 into the chamber 81, these are combined in the chamber 81 and discharged to the suction chamber 2B, and as a result, the capacity of the compressor becomes zero.

During full load operation of the pressure Ii machine, the control valve 58 generates a high control pressure AP. Then, this high control pressure AP enters the IIIJII pressure chamber 80,
Press the inner end surface of the piston 56. Thus, the piston 56 retreats against the elastic force of the coil spring 83.
Its outer end occupies a position where it abuts against the spring receiver 82, that is, the position shown in FIG. In this state, the communication holes 89a, 8
9b and the communication hole 92 are both closed by the piston 56, so that the gas compressed in the compression chambers 19a and 19b and reaching the center of the spiral is discharged through the discharge port 29 and the discharge hole 53.
The discharge valve 30 is pushed open to be discharged into the discharge cavity 31, and then to the outside through a discharge port (not shown).

When reducing the capacity of the compressor, a control pressure AP corresponding to the reduction rate is generated at the control valve 58. When this control pressure AP acts on the inner end surface of the piston 56 through the control pressure chamber 80, the piston 56 reaches a position where the pressing force due to the control pressure AP and the elastic force of the coil spring 83 are balanced.
becomes still. Therefore, while the control pressure AP is low, the communication hole 8
Only compression chambers 9a and 89b are open, and compression chambers 19a and 19
The gas that is being compressed in B is discharged into the suction chamber 28 in an amount corresponding to the opening degree of the communication holes 89a and 89b, and
, 89b are fully opened, the capacity for pressure m* decreases to 50%. Furthermore, when the control pressure AP increases, the communication hole 92 opens, and when it is fully opened, the capacity of the compressor becomes zero.

In this way, the capacity of the compressor can be varied linearly from 0% to 100%.

In the above embodiment, a bypass passage is formed by the chamber 81 of the cylinder 54, the communication holes 89a, 89b, 92, etc., and this bypass passage is opened and closed by a valve mechanism such as the piston 56, the return spring 83, the spring receiver 82, etc. However, it goes without saying that the bypass passage and valve mechanism are not limited to those shown in the drawings, and may have various structures, shapes, and water scales.

(Effects of the Invention) In the present invention, a bypass port that communicates with the compression chamber is provided in the end plate of the fixed scroll, and a bypass passage that communicates the bypass port with the suction chamber formed in the housing and this passage are provided. The capacity control block, which is equipped with a valve mechanism that opens and closes, is constructed separately from the fixed scroll, and this capacity control block is fitted with the fixed scroll and fixedly installed in the housing, making it easy to process the fixed scroll and the capacity control block. This greatly reduces costs and allows the capacity control block to be easily incorporated into the housing.

Furthermore, if a capacity control block is not incorporated, it can be used as a constant capacity compressor. In this case, the fixed scroll, housing, etc. can be shared without requiring any special modification.

[Brief explanation of drawings]

1 to 7 show one embodiment of the present invention, FIG. 1 is a partial longitudinal sectional view, FIG. 2 is a perspective view taken along the line ■-■ in FIG. 1, and FIG. 4 is a sectional view taken along the line m-m in the figure, FIG. 4 is a sectional view taken along the line mV-TV in FIG. 6, FIG. 5 is a sectional view taken along the line V-V in FIG. FIG. 4 is a sectional view taken along the line vr--■, and FIG. 7 is a sectional view taken along the line ■--■ in FIG. Figures 8 to 10 show one example of a conventional scroll compressor.
An example is shown, FIG. 8 is a longitudinal cross-sectional view, and FIG. 9 is the IX of FIG. 10.
- Partial sectional view along line IX, FIG. 10 is x- of FIG.
FIG. 3 is a cross-sectional view taken along the X-ray. Housing...1, Fixed scroll-10, End plate-1
1, Spiral-shaped Roughbu - 弗, Orbital Scroll - 14,
End plate -45, spiral roughboo 16, compression chamber -19a
, 19b, discharge boat -29, discharge cavity -31, suction chamber -28, bypass port -33a,
33b, Capacity control button)--50, Bypass path--54, 81, 89a, 89b, 92,
Valve mechanism -56, 82, 83 Fig. 1 Fig. 4 Fig. 5 Fig. 6 Fig. 7

Claims (1)

[Claims] A compression chamber is formed by meshing a fixed scroll and an orbiting scroll each having a spiral wrap erected on an end plate at different angles from each other, and the fixed scroll is fixedly installed in a housing, and the orbiting scroll is prevented from rotating by an autorotation prevention mechanism and rotated by a rotation drive mechanism to move the compression chamber toward the center of the spiral while reducing its volume to compress the gas, and this compressed gas is In a scroll compressor that discharges into a discharge cavity formed in the housing through a discharge port provided in an end plate of a fixed scroll, a bypass port that communicates with the compression chamber is bored in the end plate of the fixed scroll, A capacity control block incorporating a bypass passage that communicates the bypass port with a suction chamber formed in the housing and a valve mechanism that opens and closes this passage is configured separately from the fixed scroll,
A scroll type compressor characterized in that the capacity control block is fixedly installed in the housing by fitting with the fixed scroll.