JP4329053B2 - Variable capacity swash plate compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a variable displacement swash plate compressor, and more particularly to a variable displacement swash plate compressor characterized by a fixed structure between a shaft and a thrust flange.
[0002]
[Prior art]
As a conventional variable capacity swash plate compressor, a shaft, a swash plate slidably and tiltably mounted on the shaft, a crank chamber accommodating the swash plate, and a shaft are fitted via a link mechanism. There is a thrust flange that transmits a rotational force to the swash plate, and the tilt angle of the swash plate changes according to the pressure change of the crank chamber, and the stroke amount of the piston changes.
[0003]
FIG. 6 is a broken sectional view for explaining a fixing structure between a shaft and a thrust flange of a conventional variable displacement swash plate compressor.
[0004]
A center hole 540 b is formed in the boss portion 540 a of the thrust flange 540.
[0005]
The diameter of a part of the shaft 505 (part where the thrust flange 540 is fitted) 505a is larger than the diameter of the other part of the shaft 505.
[0006]
A thrust flange 540 is fixed to the shaft 505 by press-fitting. A rotational force and an axial force act on a fixed portion between the shaft 505 and the thrust flange 540.
[0007]
Since both the shaft 505 and the thrust flange 540 are made of an iron-based material, there is almost no decrease in the press-fitting allowance due to the difference in thermal expansion between them.
[0008]
[Problems to be solved by the invention]
However, if the shaft 505 and the thrust flange 540 are both made of an iron-based material, the weight of the compressor becomes heavy, and the demand for weight reduction cannot be met.
[0009]
As a method of solving this problem, a method of forming a thrust flange with an aluminum-based material is conceivable.
[0010]
3 to 5 are views for explaining a fixing structure between the shaft and the thrust flange of the variable capacity swash plate compressor. FIG. 3 shows a state in which the thrust flange 240 is fixed to the shaft 205 by shrink fitting. FIG. 4 is a broken sectional view showing a state in which the thrust flange 340 is fixed to the shaft 305 with two spring pins 370, and FIG. 5 shows a state in which the thrust flange 440 is fixed to the shaft 405 with the key 471. FIG.
[0011]
The thrust flanges 240, 340, and 440 shown in FIGS. 3 to 5 are all made of an aluminum-based material.
[0012]
According to the fixing structure shown in FIGS. 3 to 5, it is possible to reduce the weight of the compressor by reducing the weight of the thrust flanges 240, 340, and 440.
[0013]
However, these fixed structures have the following problems.
[0014]
The fixing structure shown in FIGS. 3 and 4 has a problem that since the axial length of the fixing portion is increased, the size of the compressor is increased and it is difficult to reduce the weight.
[0015]
The fixing structure shown in FIGS. 4 and 5 has a problem that the number of parts is increased because the spring pin 370 and the key 471 are used, and the processing of the hole 372 and the groove 473 is required, resulting in an increase in manufacturing cost.
[0016]
The present invention has been made in view of such circumstances, and an object thereof is to provide a variable capacity swash plate compressor that can be reduced in size and weight at low cost.
[0017]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a variable capacity swash plate compressor according to the first aspect of the present invention includes a shaft, a swash plate slidably mounted on the shaft, and a crank chamber for housing the swash plate. A thrust flange that is fitted to the shaft and transmits a rotational force to the swash plate through a link mechanism, and an inclination angle of the swash plate changes according to a pressure change in the crank chamber, and a stroke amount of the piston In the variable capacity swash plate compressor in which the pressure changes, a flange portion provided on the shaft and contacting a rear surface of the boss portion of the thrust flange, and provided on the shaft and fitted to the boss portion of the thrust flange. And a spline part.
[0018]
As described above, since the collar portion contacting the rear surface of the boss portion of the thrust flange is provided on the shaft, when the axial force is applied to the shaft on the front side, the rear surface of the boss portion of the thrust flange is the collar surface. Axial force is received through the part.
[0019]
Further, since the spline portion that is fitted to the boss portion of the thrust flange is provided on the shaft, a rotational force acts on the fixed portion between the boss portion of the thrust flange and the spline portion of the shaft, that is, the spline fitting portion. .
[0020]
Thus, 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.
[0021]
A variable displacement swash plate compressor according to a second aspect of the present invention is the variable displacement swash plate compressor according to the first aspect, wherein the variable displacement swash plate compressor is provided at a position adjacent to the spline portion of the shaft in the axial direction. It has a press-fitting part that is press-fitted into the boss part of the flange.
[0022]
The boss portion of the thrust flange and the shaft are more reliably coupled, the centering accuracy is improved, and rattling is suppressed.
[0023]
A variable displacement swash plate compressor according to a third aspect of the present invention is the variable displacement swash plate compressor according to the first or second aspect, wherein the shaft is made of an iron-based material and the thrust flange is an aluminum-based compressor. It is formed of a material.
[0024]
Since the weight of the thrust flange is light, the compressor is lightened accordingly.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0026]
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.
[0027]
A rear head 3 is fixed to one end surface of the cylinder block 1 of the variable displacement 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.
[0028]
A crank chamber 8 is formed in the front head 4, and a swash plate 10 is accommodated in the crank chamber 8. On the sliding surface 10 a of the swash plate 10, a shoe 50 is supported by a retainer 53 that supports the spherical one end 11 a of the connecting rod 11 so as to allow relative rolling. A bearing 55 is attached to the boss portion 10 b of the swash plate 10, and the retainer 53 is attached to the boss portion 10 b of the swash plate 10 via the bearing 55, and the retainer 53 can rotate relative to the swash plate 10. The bearing 55 is prevented from coming off by a nut 54 screwed into the boss portion 10b. The other end 11 b of the connecting rod 11 is fixed to the piston 7.
[0029]
The shoe 50 includes a shoe main body 51 that supports the front end surface of the one end portion 11a of the connecting rod 11 so as to allow relative rolling, and a washer 52 that supports the rear end surface of the one end portion 11a of the connecting rod 11 so as to allow relative rolling. Has been.
[0030]
A discharge chamber 12 and a suction chamber 13 are formed in the rear head 3. The suction chamber 13 is disposed so as to surround the discharge chamber 12. The rear head 3 is provided with a suction port 3a that leads to the outlet of an evaporator (not shown).
[0031]
The refrigerant gas at the suction port 3 a is guided to the suction chamber 13 through a suction passage 39 formed in the rear head 3. A valve accommodating space 134 is provided in the middle of the suction passage 39, and the bottomed cylindrical suction control valve 30 is slidably accommodated in the valve accommodating space 134. A spring 32 is accommodated in the suction control valve 30. Refrigerant gas introduced from the crank chamber 8 through the passage 60 is applied to the bottom surface portion 30a of the suction control valve 30 while the pressure of the refrigerant gas at the suction port 3a acts in the valve opening direction (direction in which the valve opening increases). 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).
[0032]
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 is opened and the passage is opened, and the discharge chamber 12 and the crank chamber 8 are in communication with each other. When the heat load is large, the control valve 81 is closed and the passage is blocked. The discharge chamber 12 and the crank chamber 8 are not in communication.
[0033]
The suction chamber 13 and the crank chamber 8 communicate with each other via a passage 58.
[0034]
The valve plate 2 is provided with a discharge port 16 that allows the compression chamber 82 and the discharge chamber 12 to communicate with each other, and a suction port 15 that allows the cylinder bore 6 and the suction chamber 13 to communicate with each other at predetermined intervals in the circumferential direction. . 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 face of the valve plate 2 by a bolt 19 together with a valve presser 18. The bolt 19 is formed at the center of the cylinder block 1 and is screwed to the screw 1b.
[0035]
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 attached to the outer peripheral surface on the rear side of the shaft 5.
[0036]
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 a radial bearing 26.
[0037]
A thrust flange 40 for transmitting the rotation of the shaft 5 to the swash plate 10 is fixed to the shaft 5, and 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 a virtual plane orthogonal to the shaft 5.
[0038]
The shaft 5 is made of an iron-based material, and the thrust flange 40 is made of an aluminum-based material. The shaft 5 is formed with a press-fit portion 5a and a spline portion 5b adjacent to each other. Splines are formed on the spline portion 5b 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 part 5a is set to such an extent that it does not become zero even when thermal expansion during compressor operation is taken into consideration. A flange portion 61 is mounted on the rear side of the press-fit portion 5a. The front surface of the collar portion 61 is in contact with the rear surface of the boss portion 40 a of the thrust flange 40. When an axial force (preload) to the front side is applied to the shaft 5 in order to prevent the shaft 5 from rattling, the rear surface of the boss portion 40 a of the thrust flange 40 receives the axial force via the flange portion 61.
[0039]
The swash plate 10 is slidably and tiltably attached to the shaft 5 via a hinge ball 90. A hinge ball receiving surface 10 d corresponding to the spherical portion 90 a of the hinge ball 90 is provided in the center hole of the boss portion 10 b of the swash plate 10. The spherical surface 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 wrap around the outer peripheral surface of the shaft 5.
[0040]
Next, the operation of this variable displacement swash plate type clutchless compressor will be described.
[0041]
The rotational power of an in-vehicle engine (not shown) is always transmitted to a pulley (not shown) and the shaft 5 via a belt (not shown), and the rotational force of the shaft 5 is transmitted to the swash plate 10 via the thrust flange 40 and the link mechanism 41. As a result, the swash plate 10 rotates.
[0042]
At this time, the rotational force of the shaft 5 acts on a fixed portion between the boss portion 40 a of the thrust flange 40 and the spline portion 5 b of the shaft 5.
[0043]
Since the shoe 50 relatively rotates on the rear surface 10 a of the swash plate 10 by the rotation of the swash plate 10, the rotational force from the swash plate 10 is converted into a linear reciprocating motion of the piston 7. 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. By this volume change, the refrigerant gas is sucked, compressed, and discharged in sequence, and the inclination angle of the swash plate 10 is increased. A corresponding volume of refrigerant gas is discharged. At the time of suction, the suction valve 21 is opened, and a low-pressure refrigerant gas is sucked from the suction chamber 13 into the compression chamber 82 in the cylinder bore 6. At the time of discharge, the discharge valve 17 is opened, and the high-pressure refrigerant gas from the compression chamber 82 to the discharge chamber 12. Is discharged.
[0044]
When the heat load is reduced (corresponding to clutch-off of a compressor with a clutch), the control valve 81 is opened, high-pressure refrigerant gas flows out from the discharge chamber 12 to the crank chamber 8, the pressure in the crank chamber 8 increases, The inclination angle of the plate 10 is reduced. In addition, since the flow of the refrigerant gas flowing out from the crank chamber 8 to the suction chamber 13 is throttled by an orifice (not shown) in the middle of the passage 58, a pressure drop in the crank chamber 8 is suppressed.
[0045]
During the minimum piston stroke, the refrigerant gas sequentially returns to the suction chamber 13 through the suction chamber 13, the compression chamber 82, the discharge chamber 12, the passage (passage connecting the discharge chamber 12 and the crank chamber 8), the crank chamber 8, and the passage 58. .
[0046]
When the heat load increases, the control valve 81 closes, and the flow 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. Accordingly, 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.
[0047]
The variable displacement swash plate clutchless compressor of this embodiment has the following effects.
[0048]
Since the place where the rotational force of the shaft 5 acts and the place where the axial force acts are separated, the axial length of the fixed portion between the boss portion 40a of the thrust flange 40 and the shaft 5 can be reduced, and the compressor Can be reduced in size and weight.
[0049]
In addition, since the press-fitted portion 5a of the shaft 5 is press-fitted into the boss portion 40a of the thrust flange 40, both 40 and 5 are more reliably coupled, centering accuracy is improved, rattling is suppressed, and noise is reduced. Becomes smaller.
[0050]
Furthermore, since the spring pin 370 and the key 471 are not used, the number of parts does not increase, and drilling or the like is not necessary, so that the manufacturing cost can be reduced.
[0051]
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. Portions common to the first embodiment are denoted by the same reference numerals and description thereof is omitted.
[0052]
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, press-fit portions 105a and 105c are formed on both sides of the spline portion 105b.
[0053]
According to this embodiment, the compressor can be reduced in size and weight as in the first embodiment, and the press-fit portions 105a and 105c are located on both sides of the spline portion 105b, so that the centering accuracy is further improved. In addition, the backlash of the shaft 105 can be suppressed and the noise can be further reduced.
[0054]
In each of the above-described embodiments, the collar portion 61 that contacts the rear surface of the boss portion 40a of the thrust flange 40 is configured as an independent part different from the shafts 5 and 105. However, as a modification, the collar portion 61 is replaced with the shaft 5. , 105 may be provided integrally. For example, a step is provided on the shafts 5 and 105.
[0055]
In each of the above-described embodiments, a so-called swash plate compressor is shown as an example of the variable displacement swash plate compressor. However, the variable displacement swash plate compressor of the present invention includes a swing plate compressor. The present invention can also be applied to an oscillating plate compressor. In this case, the swing plate of the swing plate compressor corresponds to the swash plate of the present invention.
[0056]
【The invention's effect】
As described above, according to the invention described in claim 1, the compressor can be reduced in size and weight at low cost.
[0057]
According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the boss portion of the thrust flange and the shaft can be more reliably coupled, the centering accuracy can be improved, and rattling can be prevented. It can be suppressed and noise can be reduced.
[0058]
According to the variable capacity swash plate compressor of the invention described in claim 3, in addition to the effect of the invention of claim 1 or 2, the compressor can be further reduced in weight.
[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 a thrust flange is fixed to a shaft by shrink fitting.
FIG. 4 is a broken sectional view showing a state in which a thrust flange is fixed to a shaft with two spring pins.
FIG. 5 is a broken sectional view showing a state in which a thrust flange is fixed to a shaft with a key.
FIG. 6 is a broken sectional view for explaining a fixing structure between a shaft and a thrust flange of a conventional variable displacement swash plate compressor.
[Explanation of symbols]
5, 105 Shafts 5a, 105a, 105c Press-fit portions 5b, 105b Spline portion 7 Piston 8 Crank chamber 10 Swash plate 40 Thrust flange 40a Thrust flange boss portion 41 Link mechanism 61 Brim portion

Claims (3)

A shaft,
A swash plate slidably and tiltably mounted on the shaft;
A crank chamber that houses the swash plate;
A thrust flange that is fitted to the shaft and transmits a rotational force to the swash plate via a link mechanism;
In the variable capacity swash plate compressor in which the inclination angle of the swash plate changes according to the pressure change of the crank chamber, and the stroke amount of the piston changes,
A collar portion provided on the shaft and contacting a rear surface of a boss portion of the thrust flange;
A variable capacity swash plate compressor having a spline portion provided on the shaft and fitted to a boss portion of the thrust flange. 2. The variable capacity swash plate compressor according to claim 1, further comprising a press-fit portion that is provided at a position adjacent to the spline portion of the shaft in the axial direction and is press-fitted into a boss portion of the thrust flange. 3. The variable capacity swash plate compressor according to claim 1, wherein the shaft is made of an iron-based material and the thrust flange is made of an aluminum-based material.

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