JP2004052623A - Swash plate type variable displacement compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a more improved swash plate type variable displacement compressor. <P>SOLUTION: The swash plate type variable displacement compressor comprises a rotatable swash plate 40, a piston 50 connected to the swash plate, a cylinder 60 for holding the piston in a movable manner, and a control valve 70 for controlling pressure on the piston. The piston has a connection portion 51 connected to the swash plate, a seal portion 52 contacting a bore of the cylinder, and a rod portion 53 supporting the connection portion and the seal portion. A wall portion 80 is provided between the connection portion and the seal portion and the rod portion passes through the wall portion. A pressure control chamber 91 communicating with the control valve is formed between the seal portion and the wall portion. The control valve controls pressure in the pressure control chamber. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a swash plate type variable swash plate including a swash plate rotatably provided, a piston connected to the swash plate, a cylinder for movably holding the piston, and a control valve for controlling a pressure applied to the piston. Related to capacity compressors.
[0002]
[Prior art]
A swash plate type variable displacement compressor is known as a compressor used in a refrigeration cycle and compressing the refrigerant gas. This type of compressor is configured such that a swash plate rotates together with a drive shaft and a piston reciprocates, thereby sucking gas into a cylinder and compressing and discharging the gas. A plurality of pistons and cylinders are arranged at equal intervals around the drive shaft. Further, the discharge amount of the refrigerant gas is controlled by changing the inclination of the swash plate and the stroke of the piston by controlling the pressure acting on the piston by a control valve. A compressor having such a configuration is also disclosed in, for example, JP-A-10-169558.
[0003]
In particular, in the case of a conventional swash plate type variable displacement compressor, the control valve is configured to guide high-pressure refrigerant gas to a crank chamber provided with a swash plate. That is, the stroke of the piston changes according to the pressure in the crankcase, and the pressure is controlled by the amount of high-pressure gas introduced into the crankcase.
[0004]
[Problems to be solved by the invention]
By the way, in the compressor, the gas compression efficiency and its durability are very important, and the pressure control by the control valve described above is required to be further rationalized from these viewpoints. For example, when a large amount of high-pressure gas is required for pressure control by the control valve, the gas compression efficiency necessarily decreases. In addition, it is not preferable to introduce high-pressure (that is, high-temperature) refrigerant gas into the crankcase in consideration of the durability of the sliding portion and the sealing means inside the crankcase.
[0005]
The present invention has been made in view of such circumstances, and an object thereof is to provide a more excellent swash plate type variable displacement compressor.
[0006]
[Means for Solving the Problems]
According to the first aspect of the present invention, a swash plate rotatably provided, a piston connected to the swash plate, a cylinder for movably holding the piston, and a pressure acting on the piston are controlled. A swash plate type variable displacement compressor provided with a control valve that performs connection, the piston supports a connection portion connected to the swash plate, a seal portion that contacts a bore of the cylinder, and the connection portion and the seal portion. A rod portion, a wall portion is provided between the connecting portion and the seal portion, and the wall portion penetrates the rod portion, and the control portion is provided between the seal portion and the wall portion. The control valve is a swash plate type variable displacement compressor configured to control the internal pressure of the pressure control chamber without a pressure control chamber communicating with the valve. According to such a configuration, labor saving of pressure control by the control valve is achieved, and a more excellent swash plate type variable displacement compressor can be obtained.
[0007]
The invention described in claim 2 of the present application is the swash plate type according to claim 1, wherein a plurality of the pistons and the cylinders are provided, and the wall portion is provided with a concave portion communicating with the inside of the pressure control chamber. It is a variable capacity compressor. That is, the inside of the pressure control chamber can be rationally communicated by providing a recess in the wall.
[0008]
The invention described in claim 3 of the present application is the swash plate type variable displacement compressor according to claim 1 or 2, further comprising a crank chamber in which the swash plate is disposed, wherein the crank chamber is configured to guide low-pressure gas before compression. is there. That is, while the conventional compressor guides the compressed high-pressure gas to the crankcase, the compressor of the present invention guides the low-pressure gas before compression to the crankcase. According to such a configuration, there is an advantage that the durability of the sliding portion inside the crank chamber is improved. It is also advantageous in securing pressure resistance.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, specific examples of the present invention will be described in detail with reference to the drawings.
[0010]
The swash plate type variable capacity compressor 1 of the present embodiment shown in FIGS. 1 and 2 is a compressor of a refrigeration cycle for in-vehicle air conditioning mounted on an automobile, and includes a front housing 11, a cylinder block 12, a rear housing 13, a valve plate 14, a rotatable drive shaft 20, a lug plate 30 provided on the drive shaft 20, a swash plate 40 mounted on the drive shaft 20 and the lag plate 30, and a swash plate 40 via a shoe 41. , A cylinder 60 for holding the piston 50 so as to be able to reciprocate, and a control valve 70 for controlling the pressure acting on the piston 50.
[0011]
In the swash plate type variable displacement compressor 1, the swash plate 40 rotates together with the drive shaft 20 and the lug plate 30, and the piston 50 reciprocates, thereby sucking gas into the cylinder 60 and compressing and discharging the gas. Further, by controlling the pressure acting on the piston 50 by the control valve 70, the stroke of the piston 50 is changed together with the inclination of the swash plate 40 to control the gas discharge amount. A plurality of pistons 50 and cylinders 60 are arranged at equal intervals around the rotation axis of the drive shaft 20. FIG. 1 shows a swash plate type variable displacement compressor 1 at the time of a full stroke, and FIG. 2 shows a time of a destroke.
[0012]
The drive shaft 20 is bridged with respect to the front housing 11 and the cylinder block 12 via bearings. The inside of the front housing 11 is a crank chamber 90 in which the lug plate 30 and the swash plate 40 are provided. The cylinder block 12 is a member that configures the plurality of cylinders 60.
[0013]
The lug plate 30 is a member fixed to the drive shaft, and an arm portion 31 for connecting the swash plate 40 is provided at a key position. The swash plate 40 includes a guide portion 42 on which a shoe 41 is mounted. The swash plate 40 is mounted on the drive shaft 20 so as to be slidable and change the tilt angle. A spring 43 is provided between the lug plate 30 and the swash plate 40 to bias the swash plate 40 and the piston 50 toward the cylinder 60 to some extent.
[0014]
Each piston 50 includes a connecting portion 51 anchored to the shoe 41, a seal portion 52 that contacts the bore 61 of the cylinder 60, and a rod portion 53 that supports the connecting portion 51 and the seal portion 52. It rotates and reciprocates with respect to the cylinder 60 respectively.
[0015]
Further, in the case of this example, a wall portion 80 is provided between the connecting portion 51 of the piston 50 and the seal portion 52, and the wall portion 80 penetrates the rod-shaped portion 53 of the piston 50, and the seal portion 52 and the wall portion 80 are formed. There is no pressure control chamber 91 communicating with the control valve 70, and the control valve 70 is configured to control the internal pressure of the pressure control chamber 91. The inclination of the swash plate 40 and the stroke of the piston 50 change according to the internal pressure of the pressure control chamber 91.
[0016]
The wall portion 80 is provided with a rod-shaped portion insertion hole 51 through which the rod-shaped portion 53 of the piston 50 is inserted, a drive shaft insertion hole 52 through which the drive shaft 20 is inserted, and an annular concave portion 83 which communicates the inside of the pressure control chamber 91. ing. The constituent member of the wall portion 80 is a plate-shaped member that closes the opening of each cylinder 60 facing the crank chamber 90 side, and is mounted between the front housing 11 and the cylinder block 12. The airtightness between the rod 53 and the rod insertion hole 81 is ensured by a metal seal structure.
[0017]
The valve plate 14 is a member provided with a suction hole 14a in which a suction valve is mounted, a discharge hole 14b in which a discharge valve is mounted, and a retainer 14c for regulating the opening of the discharge valve. It is installed between and. The suction hole 14a and the discharge hole 14b are provided for each cylinder 60, respectively. The suction hole 14a sucks gas into the cylinder 60, and the discharge hole 14b discharges gas from the cylinder 60.
[0018]
The gas is compressed between the seal part 52 of the piston 50 and the valve plate 14. The rear housing 13 mounts the control valve 70 and forms a suction chamber 92 and a discharge chamber 93 between the control housing 70 and the valve plate 14.
[0019]
The swash plate type variable displacement compressor 1 is provided with gas flow passages at key points, and the low-pressure gas, which has been circulated through the refrigeration cycle, before being compressed is first passed through the crank chamber 90 and sucked. Brought to the chamber 92. The gas is mixed with lubricating oil, and the sliding portion inside the crank chamber 90 is supplied with lubricating oil by introducing a low-pressure gas into the crank chamber 90.
[0020]
When the piston 50 moves backward, the low-pressure gas in the suction chamber 92 is sucked into the cylinder 60 from the suction hole 14a, and when the piston 50 moves forward, becomes high-pressure gas and is introduced into the discharge chamber 93 from the discharge hole 14b. The high-pressure gas in the discharge chamber 93 circulates again in the refrigeration cycle.
[0021]
The control valve 70 communicates with a pressure control chamber 91, a suction chamber 92, and a discharge chamber 93 through predetermined flow paths (not shown), and when the pressure of the low-pressure gas decreases, a bellows provided therein is provided. The valve is opened by expanding the pressure, and high-pressure gas is led to the pressure control chamber 91. When the pressure of the low-pressure gas increases, the valve closes due to the contraction of the bellows, and the high-pressure gas guided to the pressure control chamber 91 is cut off.
[0022]
The swash plate 40 reciprocates in a state where the average of the internal pressure of each cylinder 60 and the internal pressure of the pressure control chamber 91 are balanced. That is, the inclination of the swash plate 40 and the stroke of the piston 50 are controlled by the opening of the control valve 70, and the discharge amount of the high-pressure gas increases as the stroke of the piston 50 increases (see FIG. 1), and decreases as the stroke of the piston 50 decreases. Decrease (see FIG. 2).
[0023]
As described above, the swash plate type variable displacement compressor of this example has a wall provided between the connection portion of the piston and the seal portion, and a pressure control chamber between the wall portion and the seal portion. Is controlled by a control valve. According to such a configuration, it is possible to achieve labor saving in pressure control by the control valve. Particularly, in the past, the internal pressure of the crankcase was controlled, but in this example, since the internal pressure of the pressure control chamber separated from the crankcase is controlled, the internal pressure is controlled with a relatively small amount of high-pressure gas. Therefore, the gas compression efficiency can be improved. Furthermore, since it is not necessary to introduce high-pressure gas into the crankcase, there is an advantage that the durability of sliding parts such as swash plates and shoes therein is improved. It is also advantageous in securing pressure resistance.
[0024]
【The invention's effect】
The present invention includes a swash plate rotatably provided, a piston connected to the swash plate, a cylinder that movably holds the piston, and a control valve that controls a pressure applied to the piston. In the swash plate type variable displacement compressor, the piston includes a connection portion connected to the swash plate, a seal portion that contacts a bore of the cylinder, and a rod portion that supports the connection portion and the seal portion. A pressure control chamber is provided between the connecting portion and the seal portion, and a wall portion is provided, and the wall portion penetrates the rod portion, and a space between the seal portion and the wall portion communicates with the control valve. The control valve is a swash plate type variable displacement compressor configured to control the internal pressure of the pressure control chamber. According to such a configuration, a more excellent swash plate type variable displacement compressor can be obtained.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a vertical cross section of a swash plate type variable displacement compressor at full stroke according to a specific example of the present invention.
FIG. 2 is an explanatory view showing a vertical cross section of the swash plate type variable displacement compressor at the time of destroke according to a specific example of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Swash plate type variable capacity compressor 11 Front housing 12 Cylinder block 13 Rear housing 14 Valve plate 14a Suction hole 14b Discharge hole 14c Retainer 20 Drive shaft 30 Lug plate 31 Arm part 40 Swash plate 41 Shoe 42 Guide part 43 Spring 50 Piston 51 Connection part 52 Seal part 53 Rod part 60 Cylinder 61 Bore 70 Control valve 80 Wall part 81 Rod part insertion hole 82 Drive shaft insertion hole 83 Depression 90 Crank chamber 91 Pressure control chamber 92 Suction chamber 93 Discharge chamber

Claims (3)

A swash plate type variable displacement including a swash plate rotatably provided, a piston connected to the swash plate, a cylinder for movably holding the piston, and a control valve for controlling a pressure acting on the piston. In the compressor,
The piston includes a connection portion connected to the swash plate, a seal portion that contacts a bore of the cylinder, and a rod portion that supports the connection portion and the seal portion,
A wall portion is provided between the connection portion and the seal portion, and the rod portion penetrates the rod portion,
There is no pressure control chamber communicating with the control valve between the seal portion and the wall portion,
The swash plate type variable displacement compressor, wherein the control valve controls an internal pressure of the pressure control chamber. The swash plate type variable displacement compressor according to claim 1, wherein a plurality of the pistons and the cylinders are provided, and a recessed portion communicating with the inside of the pressure control chamber is provided in the wall portion. The swash plate type variable displacement compressor according to claim 1, further comprising a crank chamber in which the swash plate is disposed, wherein a low-pressure gas before compression is introduced into the crank chamber.

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