JPH0784868B2 - Scroll compressor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a scroll type compressor suitable for a vehicle air conditioner and the like.

(Prior Art) One example of a conventional device is shown in FIGS.

In FIG. 8, reference numeral 1 denotes a hermetic housing, which comprises a cup-shaped main body 2, a front end plate 4 fastened thereto by bolts 3, and a tubular member 6 fastened thereto by bolts 5. A main shaft 7 that penetrates the tubular member 6 is rotatably supported by the housing 1 via bearings 8 and 9.

A fixed scroll 10 and an orbiting scroll 14 are arranged in the housing 1.

The fixed scroll 10 includes an end plate 11 and a spiral wrap 12 provided upright on the inner surface of the end plate 11, and the end plate 11 is fastened to the cup-shaped body 2 by a bolt 13. The inside of the housing 1 is partitioned by bringing the outer peripheral surface of the end plate 11 and the inner peripheral surface of the cup-shaped body 2 into close contact with each other, a discharge cavity 31 is formed outside the end plate 11, and a suction cavity is formed inside the end plate 11. Chamber 28 is limited.

Further, a discharge port 29 is formed in the center of the end plate 11, and the discharge port 29 is opened and closed by a discharge valve 30 which is fastened together with a retainer 35 by a bolt 36 on the outer surface of the end plate 11. There is.

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

The orbiting scroll 14 and the fixed scroll 10 are eccentric to each other by the orbiting orbiting radius, and are engaged with each other with an angle of 180 ° as shown in the figure. Thus, the tip seal 17 embedded in the tip surface of the spiral wrap 12 closely contacts the inner surface of the end plate 15, and the tip seal 18 embedded in the tip surface of the spiral wrap 16 closely contacts the inner surface of the end plate 11. However, the side surfaces of the spiral wraps 12 and 16 are, as shown in FIG.
A plurality of compression chambers 19a and 19b are formed closely in c and d and are substantially point-symmetric with respect to the center of the spiral.

A drive bush 21 is rotatably fitted through a bearing 23 into a cylindrical boss 20 projecting from the center of the outer surface of the end plate 15, and an eccentric hole 24 is formed in the drive bush 21. An eccentric pin 25 eccentrically provided on the inner end of the main shaft 7 is rotatably fitted therein. A balance weight 27 is attached to the drive bush 21.

Between the outer peripheral edge of the outer surface of the end plate 15 and the inner surface of the front end plate 4, a rotation prevention mechanism 26 also serving as a thrust bearing is arranged.

Then, when the main shaft 7 is rotated, the orbiting scroll 14 is driven through the orbiting drive mechanism including the eccentric pin 25, the drive bush 21, the boss 20, etc., and the orbiting scroll 14 is prevented from rotating by the rotation preventing mechanism 26. While making a revolution revolution radius, that is, a revolution revolution motion on a circular orbit having a radius of the eccentric amount between the main shaft 7 and the eccentric pin 25. Then, the line contact portions a to d between the spiral wraps 12 and 16 gradually move toward the center of the spiral, and as a result, the compression chambers 19a and 19b move toward the center of the spiral while reducing their volumes. .

Along with this, the gas flowing into the suction chamber 28 through the suction port (not shown) is taken into the compression chambers 19a and 19b from the outer end openings of the spiral wraps 12 and 16 and is compressed into the central portion. From there, the discharge valve 30 is pushed open through the discharge port 29, discharged into the discharge cavity 31, and then discharged from there through a discharge port (not shown).

As shown in FIGS. 9 and 10, a pair of cylinders 32a and 32b, one end of which communicates with the suction chamber 28, are bored in the end plate 11 of the fixed scroll 10, and the pair of cylinders 32a and 3b are provided.
2b are located on both sides of the discharge port 29 and extend parallel to each other. Further, the end plate 11 is provided with bypass ports 33a and 33b for bypassing the gas being compressed from the pair of compression chambers 19a and 19b to the cylinders 32a and 32b.
In addition, bypass ports are provided in these cylinders 32a and 32b.
Pistons 34a, 34b for opening and closing 33a, 33b are fitted in a sealed and slidable manner, and the pistons 34a, 34b are provided with a return spring 41 interposed in a compressed state between the pistons 34a, 34b.
It is pushed toward the bottoms of the cylinders 32a and 32b by a and 41b. And, a control valve 38 is attached to the bottom of the cup-shaped body 2 so as to tightly penetrate the cup-shaped body 2.
As disclosed in Japanese Utility Model Laid-Open No. 1-34485 and Japanese Utility Model Laid-Open No. 1-179186, the control valve 38 senses the discharge pressure and the suction pressure and can represent the pressure as an intermediate pressure between these pressures and as a linear function of the low pressure. Generates control pressure.

Thus, during full load operation of the compressor, the high pressure control gas generated in the control valve 38 acts on the inner end surfaces of the pistons 34a, 34b through the holes 39a, 39b, and causes the pistons 34a, 34 to return springs 41a. , 41b are advanced against the resilience of the bypass ports 33a, 33b to close the bypass ports 33a, 33b.

On the other hand, during unloading operation of the compressor, the low-pressure control gas generated from the control valve 38 is supplied to each piston 34a, 3
It acts on the inner end face of 4b. Then, each piston 3a, 34b
Is retracted by the elastic force of the return springs 41a, 41b to occupy the position shown in the figure, and the gas in the middle of compression from the pair of compression chambers 19a, 19b passes through the bypass ports 33a, 33b and is drilled in the pistons 34a, 34b. Communication holes 42a, 42b, blind holes 43a, 43b, cylinder 32
It flows out into the suction chamber 28 via a and 32b.

(Problems to be Solved by the Invention) In the above-described conventional compressor, since the compression chambers 19a and 19b are formed point-symmetrically with respect to the center of the spiral winding,
In order to bypass the gas in the middle of compression from 19a, 19b, a pair of bypass ports 33a, 33b and a pair of cylinders 32a, 32b are formed in the end plate 11, and pistons are provided in the pair of cylinders 32a, 32b, respectively. Since it is necessary to provide two sets of 34a, 34b, return springs 41a, 41b, spring receivers 40a, 40b, etc., the structure becomes complicated, and the number of parts, the number of assembling and processing steps increase, and the cost and weight increase. was there.

Further, it is very difficult to guide the discharge pressure and the suction pressure to the control valve 38 and the control pressure generated by the control valve 38 to the cylinders 32a and 32b, which causes a problem of increasing man-hours.

(Means for Solving the Problems) The present invention has been invented to solve the above problems, and the gist of the present invention is to make the fixed scroll and the orbiting scroll housed in the housing have an angle relative to each other. A plurality of compression chambers are formed point-symmetrically with respect to the center of the vortex by sliding and engaging them, and the orbiting scroll is revolved by a revolving drive mechanism while preventing its rotation by a rotation preventing mechanism. A scroll-type compressor that compresses gas sucked into the compression chamber from a suction chamber formed inside and discharges the gas into a discharge cavity formed inside the housing, wherein the end plate of the fixed scroll is compressed during compression. A bypass port communicating with the chamber is provided, and the housing and the fixed scroll are formed separately from each other. A capacity control block having a bypass passage communicating the bypass port with the suction chamber and a valve mechanism for opening and closing the bypass passage is brought into contact with the outer surface of the end plate of the fixed scroll, and at least two contact surfaces of the capacity control block are contacted with each other. At least two or more capacity control gas passages including a gas passage that connects the pair of bypass ports to the bypass passage by forming the above-mentioned depression and interposing a sealing material integrally formed around the depression. It is a scroll compressor characterized by its limitations.

(Operation) Since the present invention has the above-described configuration, the capacity control block is brought into contact with the outer surface of the fixed scroll, and the pair of bypass ports are bypassed by interposing the seal material integrally formed on the contact surface. At least two or more capacity control gas passages including gas passages communicating with the passages are limited.

(Embodiment) One embodiment of the present invention is shown in FIGS. 1 to 7.

The end plate 11 of the fixed scroll 10 is provided with a pair of bypass ports 33a and 33b communicating with the compression chambers 19a and 19b. The capacity control block 50 is arranged so as to come into contact with the outer surface of the end plate 11 of the fixed scroll 10, and the capacity control block 50 has a fitting recess 51 provided therein and a fitting projection 10a provided in the fixed scroll 10. Is fixed in the housing 1 by inserting the bolt 13 into a bolt hole 52 formed in the capacity control block 50 and screwing the tip of the bolt 13 into the fixed scroll 10.

The housing 1 is partitioned into a suction chamber 28 and a discharge cavity 31 by sealingly sealing the rear outer peripheral surface of the capacity control block 50 to the inner peripheral surface of the cup-shaped body 2.

A discharge hole 53 communicating with the discharge port 29 is formed in the center of the capacity control block 50, and the discharge hole 53 is formed in the control block 50.
It is adapted to be opened and closed by a retainer 35 on the outer surface and a discharge valve 30 fastened with a bolt 36 at one end.

A blind hole-shaped cylinder 54 is bored on one side of the discharge hole 53, and blind hole-shaped cavities 55 are bored on the other side in parallel with the cylinder 54, and the open ends of the cylinder 54 and the cavity 55 are opened. Each communicates with the suction chamber 28.

A cup-shaped piston 56 is housed in the cylinder 54 in a sealed and slidable manner. A control pressure chamber 80 is limited to one side of the piston 56, and a chamber 81 limited to the other side communicates with a suction chamber 28. There is. The piston 56 is pushed toward the bottom of the cylinder 54 by the coil spring 83 interposed between the piston 56 and the spring bearing 82. The annular groove 93 formed on the outer peripheral surface of the piston 56 is provided with a chamber 81 through a plurality of holes 94.
Is always in communication with.

On the other hand, a control valve 58 is fitted in the cavity 55,
O-ring the gap between this cavity 55 and control valve 58
By dividing by 59, 60, 61, 62, the atmospheric pressure chamber 63,
The low pressure chamber 64, the control pressure chamber 65, and the high pressure chamber 66 are limited. The atmospheric pressure chamber 63 communicates with the atmosphere outside the housing 1 through a through hole 67 and a pressure guiding tube (not shown). The low pressure chamber 64 communicates with the suction chamber 28 through the through hole 68, and the control pressure chamber 65 has the through hole 69,
The high pressure chamber 66 communicates with the control pressure chamber 80 through the groove 70 and the through hole 71.
Communicates with the discharge cavity 31 through the through hole 72.

Like the conventional control valve 38, the control valve 58 senses the high pressure HP in the discharge cavity 31 and the low pressure LP in the suction chamber 28, and detects the intermediate pressure between these pressures and the low pressure LP. Generate a control pressure AP that can be represented as a linear function.

As shown in FIG. 7, recesses 70, 90, 91 and 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. . A seal groove 84 formed in a land portion 57 surrounding the first, second and third recesses 86, 87, 88.
The sealing material 85 fitted inside is fixed to the end plate 11 of the fixed scroll 10.
These first, second and third recesses 86, 87, 88 are formed between the volume control block 50 and the outer surface of the end plate 11 by being closely attached to the outer surface of the end plate 11, and are partitioned by the sealing material 85. . The first recess 86 communicates with the control pressure chambers 65 and 80 via the recess groove 70 and the through holes 69, 71, and the second recess 87 has a pair of bypass ports 33a formed in the end plate 11. The third recess 88 communicates with the compression chambers 19a, 19b in the middle of compression via 33b and the chamber 81 of the cylinder 54 via the communication holes 89a, 89b.
Communicating with the discharge hole 53 through 0, 91 and communicating hole 92,
It communicates with the chamber 81 of the cylinder 54 through the groove 93 and the hole 94.

The bypass ports 33a and 33b are provided at positions where the compression chambers 19a and 19b communicate with the compression chambers 19a and 19b until the compression chambers 19a and 19b finish their gas suction and enter a compression stroke and their volume is reduced to 50%. ing.

Other configurations are similar to those of the conventional one shown in FIGS. 8 to 10, and corresponding members are designated by the same reference numerals.

As a result, the control pressure AP generated by the control valve 58 during the and-load operation of the compressor decreases. When this control pressure AP is introduced into the control pressure chamber 80 through the through hole 69, the concave groove 70, and the through hole 71, the piston 56 is pushed by the restoring force of the coil spring 83 and occupies the position shown in FIG. . Thus, since the communication holes 89a, 89b and the communication hole 92 are opened, the gas in the middle of compression in the compression chambers 19a, 19b is bypass ports 33a, 3b.
3b, the second recess 87, the gas in the compression chamber that has entered the chamber 81 through the communication holes 89a, 89b and has come to the center of the spiral, that is,
The compressed gas is discharged through the discharge port 29, discharge hole 53, and third recess 8
8, the concave grooves 90, 91, the communication hole 92, the concave groove 93, the hole 94 into the chamber 81, these are merged in the chamber 81 and discharged to the suction chamber 28, as a result, the capacity of the compressor It becomes zero.

Control valve 58 during full load operation of the compressor
Generates a high control pressure AP. Then, the high control pressure AP enters the control pressure chamber 80 and presses the inner end surface of the piston 56. Thus, the piston 56 has a coil spring 83.
Of the spring bearing 82, that is, the position shown in FIG. In this state, the communication holes 89a, 89b and the communication hole 92 are all closed by the piston 56, so that the gas compressed in the compression chambers 19a, 19b and coming to the center of the spiral winding passes through the discharge port 29 and the discharge hole 53. Then, the discharge valve 30 is pushed open and discharged into the discharge cavity 31.

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 via the chamber 80,
The piston 56 is stopped at a position where the pressing force by the control pressure AP and the elastic force of the coil spring 83 are balanced. Therefore, while the control pressure AP is low, only the communication holes 89a, 89b are opened, and the gas being compressed in the compression chambers 19a, 19b is discharged to the suction chamber 28 by an amount corresponding to the opening degree of the communication holes 89a, 89b. When the communication holes 89a and 89b are fully opened as the control pressure AP increases, the capacity of the compressor decreases to 50%. Further, when the control pressure AP rises, the communication hole 92 is opened, and when it is fully opened, the capacity of the compressor becomes zero. In this way, the compressor capacity is 0% to 10%.
Change to 0%.

In the above embodiment, the chamber 81 of the cylinder 54 and the communication hole 89
A bypass passage is formed by a, 89b, 92, etc., and this bypass passage is opened and closed by the piston valve 56.
Needless to say, the bypass passage and the valve mechanism for opening and closing the bypass passage are not limited to those shown in the drawings and may have various structures and shapes.

Further, in the above embodiment, the third recess 88 communicating with the discharge port 29, the recessed grooves 90, 91, the communication hole 92, the annular groove 93, the hole 94.
Although the communication hole 92 and the communication hole 92 are provided, they can be omitted, and in this case, the capacity of the compressor can be changed between 50% and 100%. Further, the capacity variable range of the compressor can be set appropriately by appropriately changing the positions of the bypass ports 33a and 33b.

Further, the recesses 86 to 88 may be formed in the inner surface of the end plate 11 of the fixed scroll 10.

(Effect of the Invention) In the present invention, the end plate of the fixed scroll is provided with a pair of bypass ports communicating with the compression chamber in the middle of compression, and is configured separately from the housing and the fixed scroll.
A bypass control passage for communicating the bypass port with the suction chamber and a capacity control block having a valve mechanism for opening and closing the bypass passage are brought into contact with the outer surface of the end plate of the fixed scroll, and at least two contact surfaces of the same capacity control block are contacted with each other.
At least two or more capacity control gas passages including a gas passage that connects the pair of bypass ports to the bypass passage by forming the above-mentioned depression and interposing a sealing material integrally formed around the depression. Because I've reached the limit,
The capacity control block and the fixed scroll can be manufactured individually, and since these are easily processed, the cost can be greatly reduced.

Further, since the sealing material is integrally molded, it is possible to easily limit the capacity control gas passage having a complicated shape, and at the same time, it is integrally molded to limit at least two or more capacity control gas passages. It suffices to interpose the sealing material. Therefore, the number of sealing materials is small, and the workability during assembly and the reliability of the seal are improved.

[Brief description 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 II-II of FIG. 1, and FIG. Sectional view taken along line III-III of the drawing, fourth
6 is a sectional view taken along the line IV-IV of FIG. 6, FIG. 5 is a sectional view taken along the line VV of FIG. 4, and FIG. 6 is a sectional view taken along the line VI-VI of FIG. FIG. 7 is a view taken along the line VII-VII in FIG. 8 to 10 show an example of a conventional scroll type compressor, FIG. 8 is a longitudinal sectional view, FIG. 9 is a partial sectional view taken along the line IX-IX of FIG. 10, and FIG. FIG. 9 is a transverse sectional view taken along line XX of FIG. Housing …… 1, fixed scroll …… 10, orbiting scroll …… 14, compression chambers …… 19a, 19b, discharge cavity ……
31, suction chamber …… 28, bypass port …… 33a, 33b, capacity control block …… 50, bypass passage …… 54, valve mechanism …… 56, seal material …… 85, gas passage …… 87,86

Claims (1)

[Claims] 1. A plurality of compression chambers are formed point-symmetrically with respect to the center of the spiral winding by engaging a fixed scroll and a orbiting scroll, which are built in a housing, at mutually different angles, and the orbiting scroll rotates. A discharge cavity formed in the housing by compressing the gas sucked into the compression chamber from the suction chamber formed in the housing by causing the swiveling drive mechanism to revolve while revolving the rotation by the blocking mechanism. In a scroll type compressor that discharges to a fixed scroll, the end plate of the fixed scroll is provided with a pair of bypass ports communicating with the compression chamber in the middle of compression, and is configured separately from the housing and the fixed scroll. It has a bypass passage that communicates with the suction chamber and a valve mechanism that opens and closes this bypass passage. The capacity control block is brought into contact with the outer surface of the end plate of the fixed scroll, at least two or more recesses are formed on the contact surface of the capacity control block, and a sealing material integrally molded around the recess is interposed. The scroll compressor is characterized in that at least two or more capacity control gas passages including gas passages that connect the pair of bypass ports to the bypass passages are limited.