JP2001227459A - Variable displacement swash plate compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable displacement swash plate compressor allowing miniaturization/lightening at a low cost. SOLUTION: In the variable displacement swash plate compressor in which an inclined angle of a swash plate 10 is changed according to a pressure change of a crank chamber 8 and stroke quantity of a piston 7 is changed, each of a collar part 61 in contact with a rear surface of a boss part 40a of a thrust flange 40, a spline part 5b fitted into the boss part 40a of the thrust flange 40 and a force fitting part 5a which is adjacent to the spline part 5b in the axial direction and is forcibly fitted into the boss part 40a of the thrust flange 40 is provided on a shaft 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement swash plate type compressor, and more particularly to a variable displacement type swash plate type compressor characterized by a fixed structure of a shaft and a thrust flange.

[0002]

2. Description of the Related Art As a conventional variable displacement swash plate type compressor,
A shaft, a swash plate slidably and tiltably mounted on the shaft, a crank chamber for accommodating the swash plate, and a thrust flange fitted to the shaft and transmitting rotational force to the swash plate via a link mechanism. In some cases, the inclination angle of the swash plate changes according to a change in the pressure in the crank chamber, and the stroke amount of the piston changes.

FIG. 6 is a sectional view for explaining a fixing structure between a shaft and a thrust flange of a conventional variable displacement swash plate type compressor.

The boss 540a of the thrust flange 540
Is formed with a center hole 540b.

The diameter of a portion 505a of the shaft 505 (the portion where the thrust flange 540 is fitted) is
5 is larger than the diameter of the other parts.

[0006] A thrust flange 540 is fixed to the shaft 505 by press fitting. Shaft 505
A rotational force and an axial force act on a fixed portion between the shaft and the thrust flange 540.

[0007] Shaft 505 and thrust flange 540
Are formed of an iron-based material, so that there is almost no reduction in the press-in allowance due to the difference in thermal expansion between the two.

[0008]

However, the shaft 50
If both the thrust flange 5 and the thrust flange 540 are formed of an iron-based material, the weight of the compressor increases, and the demand for lighter weight cannot be met.

As a method of solving this problem, a method of forming the thrust flange with an aluminum-based material is considered.

FIGS. 3 to 5 are views for explaining a fixing structure of the shaft and the thrust flange of the variable displacement type swash plate type compressor. FIG. 3 shows that the thrust flange 240 is fixed to the shaft 205 by shrink fitting. FIG. 4 is a sectional view showing a state in which the thrust flange 340 is mounted on the shaft 305.
FIG. 5 is a cutaway view showing a state where the thrust flange 440 is fixed to the shaft 405 with a key 471. FIG.

The thrust flange 240 shown in FIGS.
Both 340 and 440 are formed of an aluminum-based material.

According to the fixing structure shown in FIGS. 3 to 5, the weight of the thrust flanges 240, 340, and 440 can be reduced, so that the compressor can be reduced in weight.

However, these fixing structures have the following problems.

The fixing structure shown in FIGS. 3 and 4 has a problem that the axial length of the fixing portion becomes large, so that the compressor becomes large, and it is difficult to reduce the weight.

The fixing structure shown in FIGS. 4 and 5 uses spring pins 370 and keys 471, so that the number of parts increases, and holes 372 and grooves 473 also need to be processed, thereby increasing the manufacturing cost. There is.

The present invention has been made in view of such circumstances, and an object thereof is to provide a variable displacement type swash plate type compressor which can be reduced in size and weight at low cost.

[0017]

According to a first aspect of the present invention, there is provided a variable displacement swash plate compressor comprising: a shaft; a swash plate slidably and tiltably mounted on the shaft; A crank chamber for accommodating the swash plate; and a thrust flange fitted to the shaft and transmitting a rotational force to the swash plate via a link mechanism. In the variable displacement swash plate type compressor in which the inclination angle changes and the stroke amount of the piston changes, a flange portion provided on the shaft and in contact with a rear surface of a boss portion of the thrust flange, and provided on the shaft, A spline portion fitted to the boss portion of the thrust flange.

As described above, since the flange portion which comes into contact with the rear surface of the boss portion of the thrust flange is provided on the shaft, when an axial force is applied to the front side of the shaft, the rear portion of the boss portion of the thrust flange is provided. The surface receives an axial force via the collar.

Further, since the spline portion fitted to the boss portion of the thrust flange is provided on the shaft,
A rotational force acts on a fixed portion between the boss portion of the thrust flange and the spline portion of the shaft, that is, a spline fitting portion.

Since the place where the rotational force acts and the place where the axial force acts are separated, the axial length of the fixed portion between the boss portion of the thrust flange and the shaft can be reduced.

According to a second aspect of the present invention, there is provided a variable displacement type swash plate type compressor according to the first aspect of the present invention, which is provided at a position axially adjacent to a spline portion of the shaft. A thrust flange having a press-fit portion press-fitted into the boss portion.

The boss portion of the thrust flange and the shaft are more securely connected, and the centering accuracy is improved.
Rattling is suppressed.

According to a third aspect of the present invention, there is provided the variable displacement type swash plate type compressor according to the first or second aspect, wherein the shaft is formed of an iron-based material;
The thrust flange is formed of an aluminum-based material.

Since the weight of the thrust flange is light, the compressor is lightened accordingly.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a variable displacement swash plate type clutchless compressor according to a first embodiment of the present invention.

A rear head 3 is fixed to one end surface of a cylinder block 1 of this variable displacement type swash plate type clutchless compressor via a valve plate 2, and a front head 4 is fixed to the other end surface. The cylinder block 1 is provided with a plurality of cylinder bores 6 at predetermined intervals in the circumferential direction around the shaft 5. A piston 7 is slidably accommodated in each cylinder bore 6.

A crank chamber 8 is formed in the front head 4, and a swash plate 10 is accommodated in the crank chamber 8. A shoe 50 that supports the spherical end portion 11a of the connecting rod 11 so as to be relatively rotatable is held by a retainer 53 on the sliding surface 10a of the swash plate 10. A bearing 55 is mounted on the boss 10b of the swash plate 10, the retainer 53 is mounted on the boss 10b of the swash plate 10 via the bearing 55, and the retainer 53 is rotatable relative to the swash plate 10. The bearing 55 includes a nut 5 screwed to the boss 10b.
4. The other end 11 b of the connecting rod 11 is fixed to the piston 7.

The shoe 50 is connected to the connecting rod 11
A shoe body 51 that supports the tip end surface of one end 11a of the connecting rod 11 so as to be able to relatively roll, and one end 11 of the connecting rod 11
a and a washer 52 that supports the rear end surface of the a.

The rear head 3 has a discharge chamber 12 and a suction chamber 13.
Are formed. The suction chamber 13 is arranged so as to surround the discharge chamber 12. The rear head 3 is provided with a suction port 3a leading to an outlet of an evaporator (not shown).

The refrigerant gas in the suction port 3a is guided to the suction chamber 13 through a suction passage 39 formed in the rear head 3. A valve housing space 134 is provided in the middle of the suction passage 39, and the bottomed cylindrical suction control valve 30 is slidably housed in the valve housing space 134. A spring 32 is housed in the suction control valve 30. The pressure of the refrigerant gas at the suction port 3a acts on the bottom surface 30a of the suction control valve 30 in the valve opening direction (the direction in which the valve opening increases), and the refrigerant introduced from the crank chamber 8 through the passage 60. The gas pressure and the urging force of the spring 32 act in the valve closing direction (the direction in which the valve opening decreases).

The discharge chamber 12 and the crank chamber 8 communicate with each other via a passage (not shown). A control valve 81 is provided in the middle of this passage. When the heat load is small, the control valve 81 opens to open the passage, and the discharge chamber 12 and the crank chamber 8 communicate with each other. When the heat load is large, the control valve 81 closes to shut off the passage. Thus, the discharge chamber 12 and the crank chamber 8 are in a non-communication state.

The suction chamber 13 communicates with the crank chamber 8 through a passage 58.

The valve plate 2 is provided with a discharge port 16 for communicating the compression chamber 82 with the discharge chamber 12 and a suction port 15 for communicating the cylinder bore 6 with the suction chamber 13 at predetermined intervals in the circumferential direction. Have been. The discharge port 16 is opened and closed by a discharge valve 17, and the discharge valve 17 is fixed to a rear head side end surface of the valve plate 2 by a bolt 19 together with a valve retainer 18. Bolt 19
It is formed at the center of the cylinder block 1 and is screwed to the screw 1b.

The suction port 15 is opened and closed by a suction valve 21, and the suction valve 21 is disposed between the valve plate 2 and the cylinder block 1. A shaft seal 91 is mounted on the outer peripheral surface on the rear side of the shaft 5.

The radial bearing 25 and the thrust bearing 24 support the rear side of the shaft 5, and the front side of the shaft 5 is rotatably supported by the radial bearing 26.

The shaft 5 is rotated by the swash plate 1.
The thrust flange 40 for transmitting to zero is fixed,
The thrust flange 40 is supported on the inner wall surface of the front head 4 via a thrust bearing 33. The thrust flange 40 and the swash plate 10 are connected via a link mechanism 41, and the swash plate 10 can be inclined with respect to an imaginary plane orthogonal to the shaft 5.

The shaft 5 is formed of an iron-based material, and the thrust flange 40 is formed of an aluminum-based material. A press-fit portion 5a and a spline portion 5b are formed on the shaft 5 so as to be adjacent to each other. Spline part 5
A spline is formed in b by rolling.
The outer diameter of the press-fit portion 5a is equal to or slightly larger than the outer diameter of the spline portion 5b. The press-fitting allowance of the press-fitting portion 5a is set to a value that does not become zero even when thermal expansion during operation of the compressor is considered. A flange 61 is mounted on the rear side of the press-fit portion 5a. The front surface of the flange 61 is in contact with the rear surface of the boss 40a of the thrust flange 40. Axial force to the front side (preload) to prevent rattling of shaft 5
Is applied to the shaft 5, the rear surface of the boss 40 a of the thrust flange 40 receives an axial force via the flange 61.

The swash plate 10 is mounted on the shaft 5 via a hinge ball 90 so as to slide and tilt. Swash plate 10
A hinge ball receiving surface 10d corresponding to the spherical portion 90a of the hinge ball 90 is provided in the center hole of the boss portion 10b. The spherical portion 90a of the hinge ball 90 is slidably fitted to the hinge ball receiving surface 10d. A winding spring 93 is mounted between the hinge ball 90 and the thrust flange 40 so as to wind around the outer peripheral surface of the shaft 5.

Next, the operation of the variable displacement type swash plate type clutchless compressor will be described.

The rotational power of a vehicle engine (not shown) is constantly transmitted to a pulley (not shown) and a shaft 5 via a belt (not shown), and the rotational force of the shaft 5 is obliquely transmitted through a thrust flange 40 and a link mechanism 41. Transmitted to the plate 10,
The swash plate 10 rotates.

At this time, the rotational force of the shaft 5 acts on a fixed portion between the boss 40a of the thrust flange 40 and the spline 5b of the shaft 5.

The rotation of the swash plate 10 causes the shoe 50 to move
The rotation of the piston 7 is converted to a linear reciprocating motion of the piston 7 because the rotation is relatively performed on the rear surface 10a of the zero. The piston 7 reciprocates in the cylinder bore 6, and as a result, the volume of the compression chamber 82 in the cylinder bore 6 changes, and the suction, compression, and discharge of the refrigerant gas are sequentially performed by this volume change. A refrigerant gas having a corresponding capacity is discharged. At the time of suction, the suction valve 21 is opened, and low-pressure refrigerant gas is sucked from the suction chamber 13 into the compression chamber 82 in the cylinder bore 6, and at the time of discharge, the discharge valve 17 is opened, and the high-pressure refrigerant gas flows from the compression chamber 82 to the discharge chamber 12. Is discharged.

When the heat load decreases (when the clutch with the clutch is turned off), the control valve 81 opens, high-pressure refrigerant gas flows from the discharge chamber 12 to the crank chamber 8, and the pressure in the crank chamber 8 increases. As a result, the inclination angle of the swash plate 10 decreases. Since the flow of the refrigerant gas flowing out of the crank chamber 8 to the suction chamber 13 is restricted by an orifice (not shown) in the middle of the passage 58, the pressure drop in the crank chamber 8 is suppressed.

At the time of the minimum piston stroke, the refrigerant gas flows into the suction chamber 13, the compression chamber 82, the discharge chamber 12, and the passage (discharge chamber 12).
And a passage 58 connecting the crank chamber 8), the crank chamber 8, and the passage 58.

When the heat load increases, the control valve 81 closes, and the inflow of high-pressure refrigerant gas from the discharge chamber 12 to the crank chamber 8 is prevented. The refrigerant gas in the crank chamber 8 gradually flows out to the suction chamber 13 through the passage 58.
Therefore, the pressure in the crank chamber 8 gradually decreases, the hinge ball 90 moves to the front side, and the inclination angle of the swash plate 10 increases.

The variable displacement swash plate type clutchless compressor of this embodiment has the following effects.

Since the place where the rotational force of the shaft 5 acts and the place where the axial force acts are separated, the thrust flange 40
The axial length of the fixed portion between the boss portion 40a and the shaft 5 can be reduced, and the compressor can be reduced in size and weight.

The boss portion 40 of the thrust flange 40
Since the press-fitting portion 5a of the shaft 5 is press-fitted into a, the two 40 and 5 are more reliably connected, the centering accuracy is improved, the rattling is suppressed, and the noise is reduced.

Further, a spring pin 370 and a key 471 are provided.
Is not used, the number of parts does not increase, and drilling and the like become unnecessary, and the manufacturing cost can be reduced.

FIG. 2 is a longitudinal sectional view showing a variable displacement swash plate type clutchless compressor according to a second embodiment of the present invention. Parts common to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the first embodiment, the spline portion 5b and the press-fit portion 5a are merely adjacent to each other, but in the second embodiment, the press-fit portions 105a, 105a are provided on both sides of the spline portion 105b.
105c was formed.

According to this embodiment, the size and weight of the compressor can be reduced in the same manner as in the first embodiment, and the press-fitting portions 105a and 105c are formed by the spline portions 105b.
, The centering accuracy is further improved, and rattling of the shaft 105 can be suppressed to further reduce noise.

In each of the above-described embodiments, the flange 61 is in contact with the rear surface of the boss 40a of the thrust flange 40.
Is composed of independent parts separate from the shafts 5 and 105,
As a modified example, a configuration in which the collar portion 61 is provided integrally with the shafts 5 and 105 may be adopted. For example, shaft 5,105
Is provided with a step.

In each of the above embodiments, a so-called single swash plate type compressor is shown as an example of the variable displacement type swash plate type compressor. However, the variable displacement type swash plate type compressor according to the present invention includes an oscillating plate type compressor. The present invention can also be applied to a rocking plate compressor. In this case, the swing plate of the swing plate compressor corresponds to the swash plate of the present invention.

[0056]

As described above, according to the first aspect of the present invention, it is possible to reduce the size and weight of the compressor at low cost.

According to the second aspect of the invention, in addition to the effects of the first aspect, the boss portion of the thrust flange and the shaft can be more securely connected, and the centering accuracy can be improved. It is possible to suppress rattling and reduce noise.

According to the variable displacement type swash plate type compressor of the third aspect of the invention, in addition to the effect of the first or second aspect of the invention, the weight of the compressor can be further reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a variable displacement swash plate type clutchless compressor according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a variable displacement swash plate type clutchless compressor according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a state in which the thrust flange is fixed to the shaft by shrink fitting.

FIG. 4 is a cutaway view showing a state in which a thrust flange is fixed to a shaft with two spring pins.

FIG. 5 is a sectional view showing a state in which a thrust flange is fixed to a shaft with a key.

FIG. 6 is a sectional view for explaining a fixing structure between a shaft and a thrust flange of a conventional variable displacement swash plate type compressor.

[Explanation of symbols]

 5, 105 Shaft 5a, 105a, 105c Press-fit portion 5b, 105b Spline portion 7 Piston 8 Crank chamber 10 Swash plate 40 Thrust flange 40a Thrust flange boss portion 41 Link mechanism 61 Collar portion

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiromichi Tanabe 39, Higashihara, Chiyo, Onan-gun, Osato-gun, Saitama F-term (reference) 3H076 AA06 BB01 BB38 cc

Claims (3)

[Claims] 1. A shaft, a swash plate slidably and tiltably mounted on the shaft, a crank chamber for accommodating the swash plate, A thrust flange for transmitting rotational force, wherein the inclination angle of the swash plate changes according to a change in pressure of the crank chamber, and a stroke amount of a piston changes, wherein the variable displacement type swash plate compressor is provided on the shaft. A flange portion that contacts a rear surface of a boss portion of the thrust flange; and a spline portion provided on the shaft and fitted to the boss portion of the thrust flange. Plate compressor. 2. The variable displacement type according to claim 1, further comprising a press-fit portion provided at a position axially adjacent to the spline portion of the shaft and press-fit into a boss portion of the thrust flange. Swash plate type compressor. 3. The variable displacement type swash plate type compressor according to claim 1, wherein said shaft is formed of an iron-based material, and said thrust flange is formed of an aluminum-based material.