JPH0429097Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Industrial Field of Application) The present invention relates to an improvement of a variable capacity swash plate compressor that adjusts the amount of refrigerant discharged according to the pressure state of the returning refrigerant.

(Prior Art) A variable displacement compressor (hereinafter referred to as a variable displacement swash plate type compressor) disclosed in Japanese Patent Application Laid-open No. 158382/1982 is known as a compressor used in recent air conditioners for automobiles.

This variable capacity swash plate type compressor adjusts the amount of refrigerant discharged from the compressor by changing the internal volume of the compression chamber in the cylinder according to the suction pressure of the refrigerant that returns to the compressor, so that the suction pressure of the compressor remains constant. It was made so that it would become so.

If the suction pressure is kept constant in this way, the refrigerant pressure at the evaporator outlet (i.e.,
The evaporation pressure of the refrigerant in the evaporator becomes constant, making it possible to avoid freezing of the evaporator during so-called low loads, and also allowing the compressor to produce a discharge amount that corresponds to the heat load. Turning on and off of the compressor by the net clutch can be reduced as much as possible. Therefore, sudden temperature changes in the blown air and sudden torque changes in engine rotation caused by turning the compressor on and off are eliminated.
Driving comfort can be improved.

As shown in FIG. 6, this variable displacement swash plate type compressor has a drive shaft 11 which is rotationally driven by an engine via a belt, a pulley and a magnetic clutch. A drive rod 11 a is provided on the drive shaft 11 and protrudes in a direction perpendicular to the drive shaft 11 so as to rotate together with the drive shaft 11 within the crank chamber 12 .

A drive swash plate 13 is connected to the drive rod 11a so as to be able to swing at an angle with respect to the drive shaft 11 using a pin 11b as a fulcrum.As shown in FIG. It is rotatably connected to a sleeve 70 that is slidably fitted onto the drive shaft 11 about two shaft pins 71, 71 as fulcrums. As a result, the rotational force of the drive shaft 11 is transferred to the drive rod 1.
1a and pin 11b to the drive swash plate 13. This drive swash plate 13 includes
A non-rotating socket plate 16 is slidably mounted via a thrust bearing 14 and a radial bearing 15.

The socket plate 16 is connected to the crank chamber 12.
The shoe 19 has a shoe 19 slidably connected to a guide pin 18 fixed to the casing, and the shoe 19 prevents rotation while allowing reciprocation in the axial direction. A plurality of piston rods 22 are attached to the socket plate 16 at equal intervals in the circumferential direction via spherical bearings 22a, and a piston (not shown) is attached to the other end of the piston rod 22 via a spherical bearing (not shown). ) are connected.

As the driving swash plate 13 rotates, the socket plate 16 performs a so-called swash-like movement and reciprocates in the axial direction, thereby causing the piston to reciprocate via the piston rod 22. The top surface side portion of the piston of the cylinder into which this piston is inserted serves as a compression chamber, and the rear side portion thereof communicates with the crank chamber 12.

(Problem to be solved by the invention) A metal bearing as a radial bearing 15 is inserted into the sliding surface 15a of the drive swash plate and the socket plate described above, and this sliding surface 15a is prevented from seizing. Therefore, lubricating oil inside the compressor is supplied. This is the 6th
As shown in FIGS. 7 to 7, a portion of the high-pressure refrigerant compressed by the piston in the compression process is transferred from the central passage 45 bored in the drive shaft 11 to the shaft pin 71 via a control valve (not shown). By guiding the high-pressure refrigerant to the sliding surface 15a of the metal bearing through the through hole 72, the lubricating oil contained in the high-pressure refrigerant is supplied to the sliding surface 15a.

However, in such a conventional variable capacity swash plate type compressor, the sliding surface covers the entire circumference,
Since the lubricating oil was formed only for a very short time, the lubricating oil discharged from the shaft pin hole together with the high-pressure refrigerant was not properly stored, and there was a risk that the sliding surface would seize.

The present invention was made in view of the problems of the conventional technology described above, and improves the lubricity of the sliding surface between the drive swash plate and the socket plate of a variable capacity swash plate compressor, thereby improving the The purpose is to improve the durability of the compressor.

[Structure of the invention] (Means for solving the problem) The present invention has a drive shaft that is rotatably inserted into the crank chamber and has a drive rod, and a drive shaft that is connected to the drive shaft so that its inclination angle can be changed. The drive swash plate has a non-rotating socket plate that is slidably attached to the drive swash plate and reciprocates in the axial direction by rotation of the drive swash plate, and a piston rod is attached to the socket plate. and a cylinder in which the piston slides, and a refrigerant compressed by the piston is supplied to the drive shaft through a control valve to the drive swash plate and the socket plate. A variable capacity swash plate compressor comprising a plurality of communicating passages guided to a sliding surface of the drive swash plate, wherein a flat portion is formed on a sliding surface of the drive swash plate with the socket plate. Thus, the above objective has been achieved.

(Function) In the present invention, since a flat portion is formed on the sliding surface of the drive swash plate and the socket plate, and the compressed refrigerant is guided to this sliding surface,
The lubricating oil contained in the compressed refrigerant is discharged onto the sliding surface and stored in the flat portion. Thereby, lubricating oil can be suitably supplied to the sliding surface.

(Example) Hereinafter, a description will be given based on the illustrated example of the present invention.

Fig. 1 is a side view showing the drive shaft portion of a variable capacity swash plate type compressor according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 5 is a variable capacity swash plate type compressor. 7 is a sectional view showing the entire compressor, in which parts common to the conventional variable capacity swash plate type compressor shown in FIGS. 6 and 7 are given the same reference numerals. FIG.

The variable capacity swash plate type compressor 3 shown in FIG. 5 has a drive shaft 11 which is rotationally driven by the engine via a belt, a pulley 2 and a magnetic clutch 2a. This drive shaft 11 includes
A drive rod 11a projects perpendicularly to the drive shaft 11 and rotates together with the drive shaft 11 within the crank chamber 12.

A drive swash plate 13 is connected to the drive rod 11a so as to be able to swing at an angle with respect to the drive shaft 11 using a pin 11b as a fulcrum. 13 is rotatably connected to a sleeve 70 that is slidably fitted onto the drive shaft 11 about two shaft pins 71, 71 as fulcrums. As a result, the rotational force of the drive shaft 11 is transmitted to the drive swash plate 13 via the drive rod 11a and the pin 11b.
It has come to be transmitted to This drive swash plate 13
A non-rotating socket plate 16 is slidably attached to the plate through a thrust bearing 14 and a radial bearing 15. In this embodiment, the radial bearing 15 is constructed by fitting a metal bearing into the socket plate 16.

The socket plate 16 is connected to the crank chamber 12.
The shoe 19 is slidably connected to a guide pin 18 fixed to the casing 17 of the shaft 17, and the shoe 19 prevents rotation while allowing reciprocating movement in the axial direction. A plurality of piston rods 22 are attached to the socket plate 16 at equal intervals in the circumferential direction via spherical bearings 22a, and a piston 23 is connected to the other end of the piston rod 22 via a spherical bearing 22b. .

As the drive swash plate 13 rotates, the socket plate 16 performs a so-called swash-like movement and reciprocates in the axial direction, thereby causing the piston 23 to reciprocate via the piston rod 22. A top surface side portion of the piston 23 of the cylinder 25 into which the piston 23 is fitted serves as a compression chamber 26, and a back side portion thereof communicates with the crank chamber 12.

The cylinder head 30 is provided with a suction port 29 and a discharge port 33, into which the return refrigerant from the evaporator flows.
The air flows into the compression chamber 26 formed in the cylinder bore against the closing elastic force of the suction valve 34 that closes the cylinder.

Further, this refrigerant is passed through a communication passage 32a that communicates with the suction port 29 formed in the cylinder head 30.
It is designed to be guided to the suction side pressure chamber 32 via.

On the other hand, the discharge port 33 is a part from which the compressed refrigerant flows out, and is communicated with a pipe (none of which is shown) that sends the refrigerant discharged from the discharge port 28 opened in the valve plate 20 to the condenser. Furthermore, it communicates with the discharge side pressure chamber 35 via the communication passage 35a.

A control valve Cv is provided between the suction side pressure chamber 32 and the discharge side pressure chamber 35, and is operated according to the pressure of the refrigerant returned to the suction port 29 of the cylinder 25.

This control valve Cv selectively opens the first valve port 40 if the pressure of the returning refrigerant is high, and the second valve port 47 if the pressure is low, and has a first control valve 36 at the bottom. , has a second control valve 39 at the top, and the first control valve 36 has a bellows 37 that expands and contracts according to the internal pressure of the suction side pressure chamber 32, and a spring 38 provided in the bellows 37. The opening degree of the first valve port 40 is adjusted by the balance of the forces.

Further, the first control valve 36 is provided with an actuation rod 46, and as described above, the second control valve 39 is opened and closed by this actuation rod 46. Both control valves 36 and 39 are designed to operate in conjunction with each other, and as mentioned above, the first
When the control valve 36 increases the opening degree of the first valve port 40, the second control valve 39 operates to decrease the opening degree of the second valve port 47.

In this embodiment, a part of the high-pressure refrigerant compressed in the compression chamber 26 flows into the discharge side pressure chamber 35, the passage 63 and the passage 48, and the center hole 44 via the second control valve 39. , and the center passage 45 are formed to communicate with each other. This central passage 45
is perpendicular to the axial direction of the drive shaft 11 at a position where the sleeve 70 and the drive shaft 11 slide. , and an opening 45b is formed so as to communicate with the drive rod 11 at a position approximately 90 degrees out of phase with the drive rod 11.

Further, the shaft pin 71 connecting the sleeve 70 and the driving swash plate 13 is formed of a cylindrical tube having a through hole 72, and as shown in FIG. In this case, the through hole 72 communicates with the opening 45b of the central passage 45 of the drive shaft 11.

Here, since the drive swash plate 13 operates in a range from the maximum inclination of the drive swash plate shown by the solid line in FIG. 1 to the minimum inclination shown by the two-dot chain line, the drive shaft 11
If the opening 45b of the central passage 45 is formed to expand in the axial direction of the drive shaft 11 over the operating range, the inclination of the drive swash plate is The refrigerant can always be guided appropriately regardless of the angle.

Further, in this embodiment, a flat portion 73 is formed on the sliding surface 15a of the driving swash plate 13 in the vicinity of the insertion portion of the shaft pin 71. This flat portion 73 is connected to the drive shaft 11 as shown in FIG.
in the direction of the drive rod 11a, that is, the drive rod 11a
The sliding surface 15a of the drive swash plate 13 is located forward in the rotational direction of the drive swash plate 13.
The length L in the direction of rotation is suitably selected depending on the usage conditions.

The operation of the embodiment configured as described above will be explained with reference to FIG.

When the heat load in the cooling cycle is small, the pressure of the return refrigerant does not reach a sufficient amount of superheat and returns at a low pressure, so the pressure in the suction side pressure chamber 32 (hereinafter referred to as suction pressure Ps) becomes low, and the bellows 37 extends upward, widens the second valve port 47, and releases the piston 23 in the compression process from the discharge port 28.
High-pressure refrigerant compressed by (hereinafter referred to as discharge pressure Pd)
is introduced into the crank chamber 12 from the second valve port 47 through the passage 62 → passage 63 → passage 48 → center hole 44 → center passage 45.
This will increase the internal pressure of No. 2 (hereinafter referred to as crank chamber pressure Pc).

At this time, the lubricating oil contained in the high-pressure refrigerant flows from the opening 45b of the central passage 45 to the sliding surface 15 between the drive swash plate 13 and the socket plate 16.
The lubricating oil is supplied to the metal bearing 15, which is the lubricating oil, and is constantly stored in the flat portion 73 formed near the opening 45b. Then, as shown in FIG. 2, the drive shaft 11 is connected to the drive rod 1.
1a in the direction of the arrow, the flat portion 7
The lubricating oil stored in the drive rod 11a gradually forms a film on the sliding surface 15a of the drive swash plate 13 and the socket plate 16, and the lubricating oil stored in the drive rod 11a has the largest sliding surface load.
The effect will be suitably demonstrated in some parts.

By introducing the above-described high-pressure refrigerant Pd into the crank chamber 12, the angle of inclination of the socket plate 16 is controlled by the balance of pressures applied before and after the plurality of pistons 23. In other words, when the pressure Pc in the crank chamber 12 becomes even slightly larger than the pressure on the suction side, the combined force of the forces applied to the back surface of the plurality of pistons 23 acts on the socket plate 16 as a moment about the pin 11b, and this This acts to reduce the angle of inclination of the socket plate 16.

For this reason, the piston 23 in the suction process cannot retreat to a sufficiently large stroke.
When the next compression step is entered, only a small compression stroke can be performed. As a result, the amount of compressed refrigerant is reduced, the amount of discharged refrigerant is small, and the flow rate of refrigerant circulating within the cooling cycle is reduced, resulting in an appropriate amount of refrigerant corresponding to the low heat load. Due to this decrease in the amount of refrigerant, the suction pressure Ps of the compressor 3 gradually increases, and as a result, the suction pressure Ps is kept constant.

3 and 4 are a side view and a sectional view showing a drive shaft portion of a variable capacity swash plate type compressor according to another embodiment of the present invention.

In this embodiment, the flat portion 73a formed in the first embodiment is formed by cutting off the entire area around the through hole 72 of the shaft pin 71. Even in this case, as in the first embodiment, the lubricating oil contained in the high-pressure refrigerant can be stored in the flat portion 73a, and the lubricating oil can be suitably applied to the sliding surface 15a of the drive swash plate 13. can be supplied. Moreover, the manufacturing operation of the drive swash plate 13 can be simplified compared to the case of the first embodiment.

In this way, in the embodiment of the present invention, the through hole of the shaft pin connecting the sleeve and the drive swash plate is used to form a flat part near the outlet of this through hole, and lubricating oil is constantly applied to this flat part. Because it is stored, it can be manufactured with a simple processing process,
Moreover, lubricating oil can always be supplied to the sliding surface of the drive swash plate.

[Effects of the invention] As described above, according to the invention, a flat portion is formed on the sliding surface of the drive swash plate and the socket plate, and the compressed refrigerant is guided to this sliding surface. The lubricating oil contained in the compressed refrigerant is discharged onto the sliding surface and stored in the flat portion. Thereby, lubricating oil can be suitably supplied to the sliding surfaces, and seizing of the sliding surfaces can be prevented, thereby achieving a great practical effect of improving the durability of the compressor.

[Brief explanation of drawings]

Fig. 1 is a side view showing the drive swash plate portion of a variable capacity swash plate compressor according to an embodiment of the present invention, Fig. 2 is an enlarged sectional view taken along the - line in Fig. 1, and Fig. 3 is the present invention FIG. 4 is a side view showing a drive swash plate portion of a variable capacity swash plate compressor according to another embodiment of the present invention;
The figure is an enlarged cross-sectional view taken along the - line in Figure 3;
The figures are a sectional view showing the entire variable capacity swash plate compressor according to the present invention, FIG. 6 is a sectional view showing the drive shaft portion of a conventional variable capacity swash plate compressor, and FIG.
The figure is also an exploded perspective view. 11... Drive shaft, 11a... Drive rod, 12...
Crank chamber, 13... Drive swash plate, 14a... Sliding surface, 16... Socket plate, 22... Piston rod, 23... Piston, 25... Cylinder, 44... Center hole (communication path), 45 ...Center passage (communicating path), 48, 62, 63...Passage (communicating path), 70...Sleeve, 71...Shaft pin,
72...Through hole (communication path), 73, 73a...Flat part, 3...Variable capacity swash plate compressor, Cv...
...control valve.

Claims (1)

[Claims for Utility Model Registration] 1. A drive shaft 11 that is rotatably inserted into the crank chamber 12 and includes a drive rod 11a, and a drive swash plate that is connected to the drive shaft 11 so that its inclination angle is variable. 13, and a non-rotating socket plate 16 which is slidably attached to the drive swash plate 13 and reciprocates in the axial direction by rotation of the drive swash plate 13.
It has a piston 23 connected to the drive shaft 1 via a piston rod 22, and a cylinder 25 in which the piston 23 slides.
1, a plurality of communication passages 44, 45, 4 that guide the refrigerant compressed by the piston 23 to the sliding surface 15a of the drive swash plate 13 and the socket plate 16 via the control valve Cv.
8, 62, 63, and 72, wherein a flat portion 73 is formed on a sliding surface 15a of the drive swash plate 13 with the socket plate 16. 2 The flat portion 73 connects the communication paths 44, 45,
48, 62, 63, 72, the sliding surface 1 of the drive swash plate 13 is located close to the crank chamber side outlet.
2. The variable capacity swash plate type compressor according to claim 1, wherein the variable capacity swash plate compressor is formed by cutting off at least the drive rod 11a side of the compressor 5a.