JPS5882083A - Variable capacity compressor - Google Patents

Abstract

PURPOSE:To simplify the structure of the titled compressor by a method wherein a relief hole in the rear surface of a spool is opened or closed by a pilot valve which is loosely fixed to a rod operated by an electromagnet so that the movement of the rod is transmitted to the spool without the intermediary of the pilot valve. CONSTITUTION:A discharge chamber 35 and an operation chamber 70 are made to communicate with each other through a pressure introducing hole 71 drilled through a rear housing 19, the operation chamber 70 is made to communicate with swash plate chamber 21 through the relief hole 72 of the spool 59, communication holes 63, 44a and an axial hole 15a and the relief hole 72 is opened and closed by the pilot valve attached to the top end of the rod 74 operated by the electromagnet 68. As a consequence, the transmission of the operation of the rod to the spool 59 is made possible without the intermediary of the pilot valve 78 by the provision of only a single valve mechanism including the spool 59, the relief hole 72, the rod 74 and the pilot valve 78 so that the structure of the compressor is simplified to thereby reduce the manufacturing cost and the leakage of a gas is prevented.

Description

[Detailed description of the invention] This invention relates to a variable capacity compressor.

In a vehicle cooling system, it is desirable to reduce power loss by changing the cooling capacity, that is, the capacity of the compressor, depending on the cooling load, and the applicant has already developed a variable capacity compressor that alternates the capacity between 100% and 50%. We offer and provide switchable swash plate type variable capacity compressors. (Special application 1986-1
(No. 51298 Publication) Although not shown, a spool is attached to the inner central part of the Llano Uging so as to be movable in the axial direction, and the first opening/closing valve is opened to apply discharge pressure to the back surface of the spool. The discharge valve is suppressed by the plate, compression is enabled on the rear side, and the valve is operated 100 times, and conversely, the first on-off valve is closed and the second on-off valve is opened to apply suction pressure to the back of the spool. The discharge valve is held floating from the plate to disable the compression operation on the rear side and switch to 50% operation.

However, the above-mentioned compressor has two first and second compressors. Since it is necessary to provide a second on-off valve and two corresponding impulse pipes and electric circuits, the structure is not only complicated, but also
The problem was that there was a big concern about gas leakage, and the cost would further increase.

In order to eliminate the above-mentioned defects, the applicant has recently developed a discharge outlet attached to the spool 3 by means of a rod 4 which is pushed toward the spool 3 by the excitation of an electromagnet 2 on the back side of the llano-using 1, as shown in FIG. In addition to pressing the valve 5 against the valve plate 6, the llano housing 1 is provided with a pressure guiding hole 9 for communicating the working chamber 7 formed on the back surface of the spool 3 with the discharge chamber 8, and furthermore, the spool 3 is K is a relief hole 10 through which the gas in the working chamber 7 is released to the swash plate chamber communicating with the suction chamber, and K is a relief hole when the spool 3 and discharge valve 5 are pressed against the valve plate 6 by the rod 4. 10 is closed by the tip of the rod 4, the electromagnet 2 is demagnetized, and the rod 4 is separated from the spool 3 by the spring 11.
A swash plate compressor is proposed in which the discharge valve 5 is lifted off the valve plate 6 by the spring 12 when the valve e is opened.

However, although this compressor has a simplified structure and is effective in preventing gas leakage, it has the following drawbacks. In other words, the spool 3 at the tip of the rod 4
, the rod tip and the relief hole 10 of the spool are easily damaged, and it is difficult for the rod 4 tip to come into close contact with the relief hole 10, resulting in poor sealing.If this seal is prioritized, the electromagnet 2
A certain dimensional tolerance is required for the rod 4 and the electromagnet 2, and as a result, the rod 4 cannot be closely inserted into the electromagnet 2.
The suction operation of the rod 4 by the electromagnet 2 becomes unstable.

The present invention has been made in order to eliminate the above-mentioned defects, and its purpose is to provide a capacity switching system that allows the spool and discharge valve to be pressed against the valve plate by a rod actuated by an electromagnet against the back surface of the spool. In the mechanism, a pilot valve is loosely attached to the rond, and the pilot valve opens and closes a relief hole opened on the back of the spool, and the rond is connected between the rond and the spool without passing through the pilot valve. By transmitting gas to the spool, it is possible to simplify the structure, reduce costs, prevent gas leaks, and eliminate damage to the rond, spool, or pilot valve, resulting in variable capacity that provides stable operation. Our goal is to provide compressors.

An embodiment in which the improved invention of the present application is embodied in a swash plate compressor will be described below with reference to FIGS. 2 to 7. Both ends of the opposed cylinder blocks 14 and 15
The front and rear housings 18 and 19 are interposed between the front and rear housings 18 and 19, and these are connected by an appropriate number of ports 20.

A swash plate chamber 21 is located at the joint part of the cylinder block 14.15.
A swash plate 23 fixed to a drive shaft 22 passing through shaft holes 14a and 15a formed through the centers of both cylinder blocks 14 and 15 is accommodated therein. Drive shaft 2
2 passes through the boss portion 24 of the cylinder block 14.15.
．． Radial bearings 26 and 27 for supporting the drive shaft 22 are press-fitted into the shaft 25, and thrust bearings 28 and 29 are interposed between the boss portions 24 and 25 and the swash plate 23. The cylinder block 14.15 has a drive shaft 22
5 at a radial position parallel to the drive shaft 22 and centered on the drive shaft 22.
A pair of cylinder bores 30 are bored, and the pistons 31 fitted in these cylinder bores 30 are moored to the swash plate 23 via a bearing member consisting of a ball 32 and a shoe 33, and the rotational force of the swash plate 23 causes the piston to move. It is possible to reciprocate within the 31Fi cylinder pore 30.

Discharge chambers 34' and '35 are formed in the center of the front and rear housings 18, 19, and a substantially annular suction chamber 36 surrounds the discharge chambers 34, 35 on the outer periphery.
．． 37 is formed, especially the front side discharge chamber 34
is formed in an annular shape, and the rear discharge chamber 35 is formed in a circular shape as shown in FIG. The suction chamber 38.37 is communicated with the swash plate chamber 21 through a suction passage 38.39 which also serves as the through hole of the cylinder block 14.15.
It communicates with the lunge 40.

As shown in FIG. 5, the cylinder blocks 14 and 15 have valve plates 16. A discharge passage 4 from the contact surface with j7 to the joint surface
1.42 are bored, and one end of the discharge passage 41.42 communicates with a discharge flange 43 mounted near the joint surface of the cylinder block 14.15, respectively, and a communication passage 44.
45, and the other end communicates with the discharge chamber 34.35 via a communication hole 46.47 provided through the valve plates 16, 17. Note that the discharge chambers 34 and 35 are discharge passages 41.
A communicating portion with 42 is appropriately bulged toward the outer circumferential side. (4th
(See figure) Venue, rear side discharge passage 42 and discharge flange 4
A check valve 48 for opening and closing the communication passage 45 is provided in the communication passage 45 connecting the rear discharge chamber 3.
5 is in a low pressure state, the communication passage 45 is closed, and in a high pressure state, the communication passage 45 is opened.

A suction port 49.50 and a discharge port 51.52 are provided through the valve plate 1s;

The pores 30 are respectively connected to the suction chamber 36, 37 and the discharge chamber 3.
4.35, and a suction valve 53.54 and a discharge valve 55.56 are disposed at the suction port 49.50 and the discharge port 51.52, respectively.

Further, the amount of deformation of the discharge valves 55, 56 is regulated by valve holders 5'7, 5'8, and on the front side they are fixed to the valve plate 16 together with the valve holder 57, but on the rear side they are fixed to the valve plate 16. If there is, the valve holder 58 and the normal closed position and the discharge port 52
It can be moved to the open position where it is opened. That is, the rear side valve holder 58 holds the discharge valve 5 as shown in FIG.
Same shape as 6! 7 annular base 58& and each outlet 52
As shown in FIG. 2, the discharge valve 56 and the valve holder 58 are overlapped with each other, and a step concentrically abuts against the back surface of the valve holder 58. A cylindrical spool 59 having a surface 59a and a pole) 6
0, and is slidably fitted in the axial direction by a horizontally short cylindrical support cylinder part 61 integrally formed in the center of the rear housing 19. Note that the eight members integrated by bolts 60 are connected to positioning pins/6 implanted in the support cylinder portion 61 of the rear housing 19.
Rotation is prevented by 2.

On the other hand, a communication hole 63 is provided in the center of the rear-side valve plate 17 to communicate the shaft hole 15a extending through the center of the cylinder block 15 and the discharge chamber 35. Radial bearing 27 that supports the rear end of the drive shaft 22
A bottomed elliptical cylindrical spring receiver 64 is interposed between the rear end and the valve plate 17, and the bottom surface of the spring receiver 64 and the discharge valve 56
A first spring 65 is interposed between the discharge valve 56 and the center thereof to always bias the discharge valve 56 in the open direction. Further, the rear side discharge chamber 35 is
The swash plate chamber 21 can be communicated with the swash plate chamber 21.

An electromagnet 68 consisting of a case 66 and a coil 67 disposed annularly within the case is joined to the back surface of the rear housing 19 so as to cover the rear end opening of the support tube 61. Bolt (
It is housed in a sub-housing 69 which is tightened and fixed by a screw (not shown).

As shown in FIG. 6, a working chamber 70 is defined on the inner circumferential surface of the support tube B1, the back of the spool 59, and the front of the case 66, and the working chamber 70 is transparent to the support tube 61. It is communicated with the discharge chamber 35 through a pressure guiding hole 71 provided therein. A relief hole 72 is provided in the center of the spool 59 and the bolt 60 in the axial direction so that the working chamber 10 and the shaft hole 15a can communicate with each other.

An insertion hole T3 is provided in the center of the case 66 of the electromagnet 68 in the axial direction of the drive shaft 22, and a rod 74 that is pushed toward the spool 59 by excitation of the electromagnet 68 is tightly fitted into the insertion hole 73. It is inserted. This rod 74 has a cylindrical part 75 made of a non-magnetic material that is directly supported by the case 66, and a core part 76 made of a magnetic material that is located on the rear side and is attracted to the spool 59 when the electromagnet 68 is excited. The spool 59 is separated from the spool 59 by a second spring T7 interposed between the flange 7S& formed at the back of the case 66 and the rear end of the core 76. is biased in the direction. A pilot valve 78 that can open and close the relief hole 72 in correspondence with the back surface of the spool 59 so as to be movable relative to the axial direction is loosely screwed to the tip of the rod 74. (See FIG. 7) Further, on the tip end surface of the rod 74, there is a thick disc-shaped opening/closing valve 79 that slides into contact with the inner circumferential surface of the support cylinder portion 61 to open and close the pressure guiding hole 71. The above-mentioned four are integrally formed with the door 4. Also, the opening/closing valve 79 is provided with a hole 79B that communicates with the working chamber 70 formed on both the front and rear sides thereof,
A recess 791) that loosely accommodates the valve head 78B of the pilot valve 78 is formed, and the thickness of the valve head 7g1aΩ is reduced to the recess 79b.
The depth of the valve head 78a is slightly smaller than the depth of the recess 79.
It allows for slight movements within b. Furthermore, between the circular annular groove 59b formed on the back surface of the spool 59 and the front surface of the on-off valve 79, the spool 59 and the on-off valve 79 are provided.
A third spring 80 is interposed to bias the two in the direction of separating them from each other. This third spring 80 and the on-off valve 79 control the movement of the rod T4 to the spool 59 without going through the pilot valve 78.
The third spring 8o has a function of transmitting information to the spool 59.
It also has the function of absorbing manufacturing errors and dimensional tolerances of the on-off valve 79 or the Ron door 4, and pressing the discharge valve 56 against the valve plate 17.

Furthermore, in this embodiment, the spool 59, the valve holder 5B
Let Ll be the combined length of the discharge valve 56 in the axial direction, L2 be the thickness of the on-off valve 79, and let the tip of the rod 74 be when the rod 74 is in its most advanced state (the collar 76a is in contact with the back surface of the case 66). If the distance from the valve plate 17 is W, then W
is slightly larger than (L1+L2) to prevent the on-off valve 79 from coming undone directly to the back surface of the spool 59.

Next, the operation of the swash plate compressor constructed as described above will be explained.

When stopped, the electromagnet 68 is in a demagnetized state as shown in FIG.
9 is urged away from the spool 59 by the second spring 77 and its position is regulated by the sub-housing 69, and the rear discharge valve 56 is moved to the open position by the first spring 65 together with the valve holder 58 and the spool 59. The communication passage 45 is closed by the reversal valve 48.

In such a state, when the electromagnetic clutch (not shown) interposed between the engine and the compressor is turned on and the compressor is driven, the front side starts operating normally and immediately enters compression action. However, since the discharge port 52 is open on the rear side, the gas only flows freely back and forth between each cylinder pore 30 and the discharge chamber 35, and moreover, the discharge chamber 35 and the suction passage 39 are Since the shaft holes 63, 64a and 15a communicate with each other through the communication holes 63, 64a and the shaft hole 15a, there is no substantial compression action and the operation is idle. In this way, at startup, operation is started with 50% capacity, and the startup torque acting on the compressor is reduced.

Thereafter, by the control action of the capacity controller (not shown), the electromagnet 68 is excited and the rod 74 is moved toward the spool 5s together with the pilot valve 78 and the on-off valve 79 against the elasticity of the second spring 77. By moving the on-off valve 79, the eighth
The spool 59, valve holder 58, and discharge valve 56 are pushed in the same direction by the spring 8o against the elasticity of the first spring 65,
The discharge valve 56 is displaced to the normal closed position and pressed against the valve plate 17, and the discharge ports 52 of the cylinder bore 30 and the valve plate 1
In order to close the communication holes 63 provided in the respective parts 7, a normal compression action is started on the rear side as well, and the reverse valve 48 is pushed up by the discharge pressure on the rear side to open the communication holes 45, and thus the compressor is activated. It is operated at a capacity of 100 cm (see Figure 8).

In the 100% operating state of this compressor, the discharge chamber 35
The compressed gas of
The pilot valve 78, which is loosely attached to the rod 74, is attracted by the gas trying to escape to the side and is brought into close contact with the back of the spool 59, closing the relief hole 72, so that the back of the spool 59 acts on the step surface 59a. A differential pressure (discharge pressure) obtained by subtracting the discharge pressure acts, and the discharge valve 56 is strongly pressed against the valve plate 1T, thereby increasing the sealing performance and efficiently performing the compression operation at 100% volume.

Thereafter, when the operation continues at the too capacity and the cooling load becomes small, and the electromagnet 6 is demagnetized by the capacity controller, the rod 74, pilot valve 78, and opening/closing valve 79 are connected to the first spring 65 to the eighth spring. 80 is moved rearward and the pressure guiding hole 71 is closed by the on-off valve 79, and the pilot valve 78 is separated from the back surface of the spool 59 to open the closed relief hole 72. Therefore, the discharge gas in the working chamber 70 passes through the relief hole 72 and returns to the low-pressure swash plate chamber 21, and the spool 59, valve holder 58, and discharge valve 56 act on the first spring 65 and the stepped surface 59a of the spool 59. Due to the discharge pressure, the discharge valve 56 is moved toward the rod 74 against the elasticity of the eighth spring 80, and the discharge valve 56 is separated from the valve plate 17 as shown in FIG. 64
B and the shaft hole 15B to the swash plate chamber 21, and the communication hole 45 is further closed by the check valve 4B. As a result, compression on the rear side is disabled and operation is performed at 50% capacity only on the front side. .

By the way, in the embodiment described above, the spool 59 has a stepped surface 59.
Since B is formed, when switching from 100% operation to 50% operation as shown in FIG.
The spool 5S1 discharge valve 56 etc. are floated from the valve plate 1T by the discharge pressure acting on the step surface 59 & other than 5, and therefore the first notch 65 moves the discharge valve 56 etc. to the valve plate 17 when operating at 50% or when stopped. It is sufficient to use something weak enough to hold it in a floating position.

A force sufficient to separate the rot valve 78 from the relief hole 72 is required, but since the cross-sectional area of the relief hole 72 is small, a weak force may be used.

Further, the eighth spring 80 becomes slightly stronger than the elasticity of the first spring 65 at the time of 100% operation as shown in FIG. 8, and presses the discharge valve 56 against the valve plate 17. 59 and the on-off valve 79 are set so as to be weaker than the first spring 65 during the capacity switching operation when they are farthest apart. In this way, in the embodiment, the first to eighth springs 65
．． 7'7゜80 is weak enough, so electromagnet 68
It is not necessary to make the capacity that large.

Now, in the embodiment of the present invention, the pressure guiding hole 71 provided through the rear housing 19 communicates the discharge chamber 35 and the working chamber 70, and the relief hole 72 of the spool 59 and the communication holes 83 and 64f are connected to each other.
The working chamber 70 and the swash plate chamber 21 are made to communicate with each other through L and the shaft hole 15a, and the relief hole 72 is opened and closed by a pilot valve 18 attached to the tip of a rod 74 operated by an electromagnet 88. Therefore, there is no need to arrange a pressure pipe on the outside of the housing, and only one set of valve mechanisms consisting of the spool 59, the relief hole 72, the rod 14, the pilot valve 78, etc. need to be provided inside the housing. It is possible to simplify the structure, reduce costs, and eliminate concerns about gas leaks.

Further, in the embodiment of the present invention, a pilot valve 78 is loosely attached to the tip of the rod 74 so as to be relatively movable, and the operation of the rod 74 is transmitted to the spool 59 via the on-off valve 78 and the eighth spring 80. As a result, it is possible to eliminate the force pushing the spool 59 from acting on the pilot valve 78, thereby increasing the durability of the pilot valve 78, and also to prevent the force pushing the spool 59 from acting on the pilot valve 78. /
(The pilot valve 7B is in close contact with the spool 5g, the rod 74, or the pilot valve 78 along the same back surface.) It is possible to absorb manufacturing errors and dimensional tolerances of the pilot valve 78, etc., and improve the sealing performance of the pilot valve 18. As mentioned above, since dimensional tolerances can be absorbed, the rod 74 can be tightly fitted into the case 66 of the electromagnet 68 without wobbling, thereby stabilizing the suction operation.

Next, an embodiment of the specific invention of the present application will be described with reference to FIG.

In this embodiment, a power transmission plate 81 that does not open or close the pressure guiding hole 71 is attached to the tip of the rod so as to be able to move slightly, and the cross-sectional area of the relief hole 72 is made larger than the cross-sectional area of the pressure guiding hole 71. % to 50 cm, the gas in the working chamber 7G is returned to the swash plate chamber 21 side.

In this embodiment of the specific invention, since the pressure guiding hole 71 cannot be closed when the capacity is reduced, the pressure in the working chamber 70 decreases, resulting in a slow switching operation, but the other configurations, functions, and effects are as described above. This is similar to the embodiment of the second invention. Note that the present invention can also be implemented in the embodiments shown in FIGS. 9 and 10. That is, the biasing force of the second spring 77', which biases the spool 59 and rod 74' to the left in the figure, is set to be larger than the biasing force of the first spring 65, which biases the discharge valve 5B in the opening direction. When the electromagnet 68 is in a de-energized state and at 100% capacity operation, the state is as shown in FIG. The feature is that it is configured to be in the state shown in FIG. 1θ, and a detailed explanation of the other configurations and their functions will be omitted.

Furthermore, the present invention can also be embodied in the following embodiments.

(1) As shown in FIG. 11, the relief hole 72 of the spool 59 is opened to the outer peripheral surface of the spool 59, and
The relief hole 72 and the suction passage 3 are connected to the rear housing 19.
Provide a relief hole 82 that communicates with 9.

(2) In the above embodiment, a capacity switching mechanism was installed on the rear side of the compressor, but a similar capacity switching mechanism was installed on the front side so that it could also be used as an unload valve at startup. . Also, for the same purpose, in a one-pull multi-tube compressor with a piston on only one side, a capacity switching mechanism is provided in all discharge chambers.

(3) Instead of the third spring 80, use an O-ring or a rubber plate. Also, this spring 8o may be omitted and the on-off valve 7
9 is pressed directly against the back of the spool 59. In this case, the collar portion 76B is prevented from coming into contact with the case 66 when the rod T4 is moved forward.

(4) Providing the suction chamber 37 around the electromagnet 68 to promote cooling of the electromagnet.

(5) To be embodied in a multi-cylinder reciprocating compressor other than a swash plate compressor.

As described in detail above, the present invention eliminates the need for pressure piping, integrates a single valve mechanism, and accommodates the valve mechanism within a housing.As a result, the structure is simplified, costs are reduced, and gas This has the effect of eliminating leakage, improving the durability and sealing performance of the valve mechanism, and providing stable capacity switching operation.

[Brief explanation of drawings]

FIG. 1 is a partial longitudinal sectional view of a conventional variable capacity swash plate compressor, and FIG. 2 is a longitudinal sectional view of a 50 inch capacity state showing an embodiment of the improved invention of the present application as a swash plate compressor. Fig. 8 is a partial longitudinal cross-sectional view of the same 100% capacity state, Fig. 4 is a cross-sectional view taken along the line X-X of Fig. 8, Fig. 5 is a longitudinal cross-sectional view of the vicinity of the discharge flange, and Fig. 6 is a partial longitudinal cross-sectional view of the capacity switching mechanism. 7 is an enlarged sectional view of section P in FIG. 6, FIG. 8 is a sectional view of only the essential parts showing one embodiment of the specific invention of the present application, and FIGS. 9 and 10 are views of other parts. FIG. 11 is a partial cross-sectional view showing the embodiment and its operating state, and FIG. 11 is a cross-sectional view showing separate relief holes. Cylinder block 15, shaft hole 15a1 valve plate 17, rear housing 19, discharge chamber 35, suction chamber 37° suction passage 39
, check valve 48, discharge valve 56, spool 59, support cylinder part 6
1. Communication hole 63.64a, first spring 65.65', case 66, coil 67, single electromagnetic stone 68, sub-housing 6
9. Working chamber 7G, pressure hole 71, relief hole? 2,82, Ron door 4.74', second spring 77.71', pilot valve 78, on-off valve 79, third spring 800 Patent applicant Toyota Industries Corporation representative Patent attorney Hironobu Onda Figure 6, Figure 7 Figure 9

Claims (1)

[Scope of Claims] l At least some of the discharge valves for the discharge ports communicating with the plurality of compression chambers and the discharge chamber are normally biased in the open direction by a spring, and A spool is attached to the back of the valve, a bottomed cylindrical working chamber is formed in the housing on the back side of the spool, and the spool is fitted so as to be movable in the axial direction, and the housing has a discharge chamber and a bottomed cylindrical working chamber. A pressure guiding hole is provided in the back surface of the spool for communicating the working chamber and applying discharge pressure to the back surface of the spool, and a relief hole is provided in the back surface of the spool to communicate the working chamber and the suction chamber side. A rod is supported at the bottom so that it can reciprocate toward the back of the spool, and an electromagnet that can attract and move the rod is installed on the outside of the rod, and the tip of the rod is configured to open and close the relief hole. A pilot valve is mounted so as to be relatively movable and transmits the operation of the rod to the spool, and a regular pilot valve of the discharge valve is provided in a passage communicating between the discharge chamber and the discharge flange side. A variable capacity compressor characterized by being provided with a check valve that opens the passage in response to displacement to a closed position. 2. The variable displacement compressor according to claim 1, wherein the cross-sectional area of the relief hole that communicates the working chamber and the suction chamber is larger than the cross-sectional area of the pressure guiding hole that communicates the working chamber and the discharge chamber. 8. The variable capacity compressor according to claim 1, characterized in that an elastic member is interposed between the rod and the spool. 4 At least some of the discharge valves for the discharge ports that communicate the plurality of compression chambers and the discharge chamber are always biased in the open direction by a spring, and a spool is attached to the back of the discharge valve. A cylindrical working chamber with a bottom is formed in the housing on the back side of the spool, and the spool is fitted therein so as to be movable in the axial direction, and the discharge chamber and the working chamber are communicated with the housing, and the spool A pressure guiding hole for applying discharge pressure is provided on the back surface of the spool, a relief hole is provided on the back surface of the spool to communicate the working chamber and the suction chamber side, and a relief hole is provided at the bottom of the working chamber toward the back surface of the spool. A rod is supported so as to be able to reciprocate, an electromagnet that can attract and move the rod is disposed on the outside of the rod, and a pilot valve that can open and close the relief hole is also relatively movable at the tip of the rod. and transmits the movement of the rod to the spool, and the distal end of the rod is provided with an on-off valve that closes the pressure guiding hole when the rod is separated from the spool, and the discharge chamber is connected to the discharge chamber. The passage that communicates with the discharge flange side is provided with a check valve that opens the passage in response to displacement of the discharge valve to the normal closed position! Variable capacity compressor with %2 characteristics.