JPH0639103Y2 - Swash plate type variable displacement compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a swash plate type variable displacement compressor, and is effectively used as a refrigerant compressor of an automobile air conditioner, for example.

[Prior art and its problems]

In the conventional swash plate type compressor, the swash plate is attached so as to be inclined with respect to the shaft, and with the inclination of the swash plate, the swing motion is transmitted to the piston through the circumference. Further, in the conventional swash plate compressor, since the inclination angle of the swash plate with respect to the shaft is constant, the piston is arranged so as to face the tip of the swash plate with a minute gap therebetween.

Therefore, in the conventional swash plate compressor, the piston is engaged with the tip of the swash plate, and this engagement prevents the piston from rotating in the cylinder.

Such a conventional piston rotation preventing method is effective when the inclination angle of the swash plate with respect to the shaft is constant, but when the swash plate is attached to the shaft in a state where the inclination angle can be changed, The conventional piston rotation preventing method cannot be adopted. That is, when the swash plate is attached to the shaft so as to be tiltable, it is necessary to provide a sufficient gap between the tip of the swash plate and the piston so that the swash plate can be tilted favorably. In other words, the inclination of the swash plate will not be displaced unless there is a sufficient gap between the tip of the swash plate and the piston.

If a sufficient gap is provided between the tip of the swash plate and the piston in this way, the piston will rotate in the cylinder due to the large gap.

If the piston rotates in the cylinder, not only a noise is generated but also the durability of the piston and the swash plate deteriorates.

[Problems to be solved by the device]

The present invention has been devised in view of the above points, and an object of the present invention is to prevent a piston from rotating in a cylinder even in a swash plate type compressor in which a swash plate is tiltably arranged with respect to a shaft. And

[Configuration and operation]

To achieve the above object, in the compressor of the present invention, the swash plate is engaged with the shaft so as to be tiltable, and the drive piston changes the tilt angle of the swash plate and the rotation center position in association with each other. As a result, the top dead center position of the cylinder chamber on one side of the piston becomes constant, and the discharge capacity becomes variable as the reciprocating stroke of the piston fluctuates. On the other hand, in the cylinder chamber formed on the other side of the piston, dead volume occurs in the cylinder chamber due to the fluctuation of the piston reciprocating stroke, and the capacity becomes variable according to this dead volume.

Further, in the compressor of the present invention, the outer shape of the pair of shoes is spherical so that the pair of shoes is arranged on both sides of the swash plate so that the inclination angle of the swash plate can be variably controlled. As a result, the outer shape of the shoe is always constant regardless of the change in the inclination angle of the swash plate, and the contact state between the shoe and the piston is reliably maintained.

On the other hand, as a result of forming the shoe in a spherical shape as described above, the piston is likely to rotate. Further, by forming the engagement means that engages with the rotation prevention means on the cylinder side, the rotation of the piston is favorably prevented by the engagement between the rotation prevention means and the engagement means.

[Effect of device]

Therefore, according to the compressor of the present invention, the displacement of the swash plate type compressor can be continuously and variably controlled by displacing the tilt angle and the rotation center position of the swash plate.

Moreover, even in the compressor in which variable displacement control is possible in this way, the rotation of the piston is reliably prevented, and the piston does not collide with the swash plate and abnormal noise is not generated.

〔Example〕

An embodiment of the compressor of the present invention will be described below with reference to the drawings.
In FIG. 1, reference numeral 100 denotes a shaft, which is a bearing 102 held by the front housing 101 and a bearing held by the housing 103.
It is rotatably supported by 104. Further, the shaft 100 receives a rotational driving force of an automobile running engine via an electromagnetic clutch (not shown). Front housing 10
A shaft seal device 105 is arranged between 1 and the shaft 100, and this shaft seal device prevents the refrigerant and the lubricating oil in the housing from leaking outward along the shaft 100. Compressor housing 120 is formed from housing 103 and housing 108 described above. Both housings 103 and 108 are cylindrical as shown in FIG. 2 and have a plurality of cylinder chambers 50 formed therein. An O-ring 109 is provided between the housings 103 and 108 to keep the seal.

A power transmission unit 130 is formed at the end of the shaft 100, and the input unit 140 of the swash plate 10 is engaged with the transmission unit 130. Especially, the input section 140 and the power transmission section 130 of the swash plate 10 are pin 80
Are connected in a freely rotatable state by. Also pin 80
Is movably held in a slit 132 formed in the power transmission unit 130.

A connecting ball 142 is rotatably connected to the center of the swash plate 10, and the connecting ball 142 is fixed to the slider 40.

Further, the slider 40 is connected via a drive piston 32 and a circlip 33. Further, a bearing 143 is arranged between the drive piston 30 and the slider to support the rotation of the slider 40. Further, the slight load received via the swash plate 10 is applied to the thrust bearing 16 and the power transmission unit 130 arranged between the slider 40 and the drive piston 30.
And a thrust bearing 146 arranged between the housing 103 and the housing 103.

Inside the cylinder 50, the piston 7 is arranged so as to be slidable back and forth. The piston 7 is arranged so as to straddle the swash plate 10, and a shoe 9 is arranged between the swash plate 10 and the piston 7. The shoes 9 are arranged on both sides of the swash plate 10, and when arranged on the swash plate 10, the outer shape of the circumference is spherical. Side plates 151 are provided at the ends of the housings 103 and 108, respectively, and the front housing 1 described above is provided outside the side inserts 150.
01 is fixed. On the other hand, the rear housing 13 is arranged outside the side plate 151. Front housing 101
Further, suction chambers 72 and 74 are formed inside the rear housing 103, and discharge chambers 90 and 93 are arranged outside the suction chambers 72 and 74. Cylinder space 50 on the side plates 150, 151
A suction hole 25 that communicates with the suction chamber and a discharge hole 24 that communicates with the cylinder space 50 and the discharge chamber are opened.

A suction valve 342 is arranged on the cylinder space 50 side of the suction hole 25, and a discharge valve 22 is arranged on the discharge chamber side of the discharge hole 24.
Is provided. Further, the discharge valve 22 is held by the valve retainer 23.

Further, the housings 103 and 108 are formed with the suction chambers 72 and 74 and the suction-side passages 71 and 73 for introducing the low temperature and low pressure refrigerant. Further, discharge side passages 91, 94 for guiding the high-temperature, high-pressure compressed refrigerant from the discharge chambers 90, 93 to the outside are also formed. Then, the discharge side passages 91, 94 are discharged to the condenser side (not shown) of the refrigeration cycle through the discharge communication holes 92, 95.

The drive piston 30 described above is arranged in the center of the rear housing 13. A suction chamber 74 is formed by the one surface 305 of the drive piston 30 and the side plate 51. A pressure chamber 200 is formed on the other surface side of the drive piston 30.
The pressure on the suction chamber 74 side is introduced into this pressure chamber via the low pressure introduction passage 97, and the pressure on the discharge chamber 93 side is introduced via the high pressure introduction passage 96. And this introduction pressure is the switching valve 400
Is controlled by switching. Further, the switching valve 400 is configured to perform switching control based on an electric signal from the controller 500.

As shown in FIG. 3, rotation preventing means is provided on the outer circumference of the piston 7.
300 are formed. Here, the piston 7 is integrally formed with the rotation preventing means 300 from an aluminum alloy or a design material. And the cylindrical portion 303 of the piston 7
In addition to the rotation prevention means 300, is cut and shaped with high precision by a lathe or the like. And this cylindrical part is the housing 103, 108
It will be slidably arranged in the cylinder space 50. The rotation preventing means 300 is formed outside the central portion of the piston. The rotation preventing means 300 is also finished by cutting or the like, and is slidably arranged in the engaging groove 310 portion of the housing 103, 108. The engagement groove 310 of the housing 103, 108 is the second
As shown in the figure, it is formed in the central portion of the compressor.

Next, the operation of the compressor having the above structure will be described. When an electromagnetic clutch (not shown) is connected and the rotational driving force of the automobile running engine is transmitted to the shaft 100, the shaft 100
And the swash plate 10 rotates in the compressor. Since the swash plate 10 is inclined with respect to the shaft plug of the shaft 100,
The swash plate 10 makes a swinging motion with the rotation. This swing is transmitted to the piston 7 via the circumference 9, and the piston 7 reciprocates in the cylinder 50.

With the reciprocating movement of the piston 50, low-temperature, low-pressure refrigerant is sucked into the cylinder chamber 50 from the suction chamber 72 during the piston suction process.
Inhaled via 25. A low-temperature low-pressure refrigerant is sucked into the suction chamber 72 from an evaporator (not shown) of the refrigeration cycle through the swash plate chamber 70 and the suction communication passages 71 and 73.

At the piston compression process position, the refrigerant is compressed as the volume of the cylinder chamber 50 decreases. When the pressure of the refrigerant in the cylinder 50 rises above a predetermined pressure, the discharge valve 22 is opened to open the discharge chambers 90, 9
The refrigerant is discharged to the 3 side. The refrigerant discharged to the discharge chambers 90, 93 is then discharged to the condenser side of the refrigeration cycle via the discharge side communication passages 91, 94.

In the compressor having the above configuration, the tilt angle of the swash plate 10 is variably controlled according to the discharge capacity required by the refrigeration cycle. That is, the switching valve 400 is switched based on the electric signal from the controller 500, and thereby the inclination angle of the swash plate 10 is controlled.

When the switching valve 400 connects the low pressure introduction hole 97 and the output passage 98, the pressure in the control pressure chamber 200 becomes the same as the pressure in the suction chamber 74. In this case, the piston 7 shown in FIG.
A reaction force when pressing a piston other than the above is transmitted to the drive piston 30 via the swash plate 10 and the slider 40, and the reaction piston displaces the drive piston in the rightmost direction as shown in FIG.

In this way, if the drive piston 30 is displaced to the right in the figure,
The inclination of the swash plate 10 with respect to the shaft 100 becomes smaller. Then, as the inclination of the swash plate 10 becomes smaller, the piston 7
The reciprocating stroke of is also small.

Here, in the compressor of this example, even when the swash plate 10 has a small inclination angle and thus the reciprocating stroke of the piston 7 has become small, the right end portion of the piston 7 in the drawing is always at the top dead center. It has a structure that can be displaced to the position. In other words, as the tilt angle of the swash plate 10 changes, the suction refrigerant flow rate decreases in the right part of the piston in FIG. 1 as the reciprocating stroke changes. At the same time, in this case, the dead volume generated between the tip of the piston 7 and the side plate 150 becomes large in the leftward portion of the piston 7 in FIG. 1, and this dead volume causes the discharge capacity of the compressor to decrease. It has become.

When a large discharge capacity is required for the compressor, the switching valve 400 switches the passage according to the electric signal from the controller 500. That is, the high-pressure side introduction passage 96 and the output passage 98
Try to communicate with. In this case, the high pressure in the discharge chamber 93 is transmitted to the control pressure chamber 200, and the drive piston 30 is displaced leftward in the figure. The displacement of the piston 30 is transmitted to the swash plate 10 via the slider 40 and the connecting ball 142. In this case, the pin 80 fluctuates in the slit 132, and as a result, the tilt angle between the swash plate 10 and the shaft 100 becomes large. Swash plate 10
The reciprocal stroke of the piston 7 also increases with an increase in the inclination angle of.

In the compressor of this example, the swash plate 1 for the shaft 100
The inclination angle of 0 will be controlled by the displacement of the drive piston 30. In order to favorably perform the tilt angle displacement of the swash plate 10, it is necessary to provide a sufficient gap between the tip 199 of the swash plate 10 and the end surface 307 of the piston 7. This is because if the tip 199 of the swash plate 10 faces the piston 7 with a minute gap, the tip 199 of the swash plate 10 collides with the piston 7 when the tilt angle of the swash plate 10 changes.

Therefore, in the compressor of this example, the tip 199 of the swash plate 10 and the piston 7
A sufficient gap of about 2 to 3 mm is formed between and. On the other hand, if such a large gap is provided, the piston 7 will rotate in the cylinder 50. If the piston 7 rotates in the cylinder 50, the end 307 of the piston 7 collides with the tip 199 of the swash plate 10, which causes abnormal noise as described above.

On the other hand, in the compressor of this example, the rotation preventing means 300 is integrally formed on the piston 7, and the rotation preventing means is engaged in the engagement groove 310. Therefore, the engagement of the anti-rotation means 300 and the engagement groove 310 prevents the piston 7 from rotating in the cylinder 50.

In the above-mentioned example, the rotation preventing means is a cylindrical saddle as shown in FIG. 3, but the rotation preventing means may have other shapes. For example, a pin may be used as the rotation preventing means. In this case, an engaging groove corresponding to the outer shape of the pin is used as the engaging means. Further, as the rotation preventing means, a groove may be formed instead of the saddle-shaped portion or the pin described above. In this case, the engaging means formed on the housing 103, 108 side is a bulging portion that fits into the groove.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a compressor of the present invention, FIG. 2 is a front view showing an end portion of a housing shown in FIG. 1, and FIG. 3 is a perspective view showing a piston shown in FIG. 7 …… Piston, 9 …… Shoe, 10 …… Swash plate, 50 …… Cylinder space, 100 …… Shaft, 103,108 …… Housing, 300…
... rotation prevention means.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hideaki Sasaya 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute, Inc. (56) Bibliography 56-25085 (JP, U) Special Kohei 4-44112 (JP, B1)

Claims (1)

[Scope of utility model registration request] 1. A housing having a plurality of cylinder spaces, a piston slidably disposed in the housing, a shaft rotatably supported by the housing, and an inclinable engagement with the shaft. A swash plate that rotates integrally with the shaft, a drive piston that variably controls the tilt angle of the swash plate, and a pair of shoes that are arranged on both sides of the swash plate to transmit the swinging motion of the swash plate to the piston. The pair of shoes are formed to have a spherical outer shape in a state of being arranged on both sides of the swash plate, and the drive piston associates the tilt angle of the swash plate with the rotation center position. The cylinder, while varying the reciprocating stroke of the piston while maintaining the top dead center position on one side of the piston, and forming rotation preventing means on the piston, A swash plate type variable displacement compressor in which engagement means for engaging with the rotation prevention means is provided to restrict rotation of the piston in the cylinder.