JPS60164684A - Compressor for car air-conditioner - Google Patents

Abstract

PURPOSE:To save energy by making an axial hole through the rotary shaft of compressor while flowing in/out refrigerant through a through-hole made radially against said axial hole thereby stopping excessive delivery of refrigerant under high speed rotation. CONSTITUTION:Under low rotation of shaft 71, refrigerant will flow smoothly from low pressure chamber 74 through four through-holes 75a, 75b and 75c, 75d (not shown) having diameter of 5phi made radially. Upon increase of rotation of shaft 71 to increase moving speed of through-hole 75a-75d, the flow speed of refrigerant at the inlet of through-hole can not catch up said moving speed thus to make thin the refrigerant flowing through an axial hole 72. Consequently, intake refrigerant is reduced substantially to lower the volume efficiency as the rotation increases. As a result, even in such compressor to be driven directly through rotation of car engine, the compressor will never deliver excessive energy under high rotation of engine resulting in elimination of useless energy consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a compressor, and more particularly to a compressor for an air conditioner for an automobile driven by an automobile engine.

[Background of the invention]

Special Publication No. S7-50943, Japanese Patent Publication No. Sho 56-141079
The compressor of the air conditioner for an automobile disclosed in Japanese Patent Laid-Open No. 51-89205 is directly driven by the automobile engine via an electromagnetic clutch. For this reason, if the compressor is designed so that a predetermined capacity can be obtained even when the engine rotational speed is low (for example, when the engine is idling), the capacity will be excessive when the engine rotational speed is high. Over-capacity of the compressor means that the compressor, and by extension the engine, are doing unnecessary work.

[Purpose of the invention]

The purpose of the present invention is to provide a compressor that obtains driving force from an automobile engine, and is capable of preventing excessive capacity during high-speed operation of the engine.
In other words, the purpose is to reduce unnecessary work and reduce the load on the engine at high speeds.

[Summary of the invention]

A feature of the present invention is that a shaft hole is formed in the rotating shaft of the compressor, and the refrigerant flows in and out through nine holes that are formed radially to the shaft hole. With this configuration, the refrigerant flowing out from the hollow part in the rotating shaft (inflowing into the hollow part) encounters greater resistance when entering and exiting as the shaft rotates faster. As a result, as the engine speed increases and the rotating shaft of the compressor rotates at a high speed, the amount of refrigerant sucked is suppressed, and the rate of decrease in volumetric efficiency increases as the speed increases. Thereby, the performance during high-speed operation can be suppressed without reducing the performance during low-speed operation.

[Embodiments of the invention]

An example in which the present invention is applied to a swash plate compressor will be described below with reference to FIGS. 1 to 3.

Regarding the compression mechanism of the swash plate type compressor,
Same as No. 50943. One feature of this embodiment is the flow path of the suction refrigerant, and this portion will be explained in detail below.

10 from the rear end of shaft 1 toward the front side of the compressor.
A φ shaft hole is drilled. This shaft hole 2 extends directly below the front thrust bearing 4 of both the front and rear thrust bearings 4.5 that sandwich the swash plate 3.

The shaft 1 has a shaft hole 2 extending radially outward,
A radial hole 6a opens on the curved surface of the shaft.

6b, 7a, and 7b are bored at 180 degree intervals at positions facing the front thrust bearing 4 and the rear thrust bearing 5, respectively.

The front boss portion 3a of the swash plate 3 has a 4φ through hole 10 extending along the front swash plate surface 3A toward the center of rotation of the shaft.
A to 10e (5 pieces) are drilled at equal intervals.

Similarly, the rear side boss portion 3b of the swash plate 3 has a rear side swash plate surface 3.
A 4φ through hole 11a facing the rotation center of the shaft along B
~IIC (5 pieces) are drilled at equal intervals.

Through holes 10a to 10 in the press-fit fixing surface between the swash plate 3 and the shaft 1
An annular groove 12.13 is cut at a position facing the inner end of the e9 through holes 11a to lie, and the respective through holes are communicated with each other through this groove. The shaft 1 has 5φ through holes 8a, 8b extending radially from the shaft hole 2 so that their outer ends open into the grooves 12.13.

5c (sb, sc not shown) and 9a, 9b.

Three holes 9C (9b and 9c are not shown) are drilled at 120 degree intervals.

After all, the shaft hole 2 communicates with the space 14 in both the front and rear cylinder blocks 15a, 15b, in which the swash plate 3 swings, via the radial holes 6a, 6b, 7a, 7b, and both thrust bearings 4, 5. .

Furthermore, through holes 8a (8b, 8C) and 9a (9b).

9c), grooves 12 and 13, and through holes 10a to 10e and ll
It communicates with the space 14 via a-lie.

A spacer 18 having a through hole 17 that communicates with the shaft hole 2 is press-fitted into the shaft insertion hole 16 located at the rear end of the shaft 1 . The rear end of the spacer 18 passes through the center of the rear side cover 19b and extends into the rear low pressure chamber 21 formed in the rear side cover 20b.

A control valve mechanism 22 is installed in the rear low pressure chamber 21 to control the amount of refrigerant sucked into the rear cylinder (not shown).

A suction side union 24 that guides the refrigerant to the low pressure chamber 21b is screwed to the rear side cover 20b so as to pass through the wall surface of the side cover 20b.

A valve case 23 constituting the valve mechanism 22 is press-fitted into the low-pressure chamber side end of the union 24, and the valve case 23 is fixed by screwing the union 2'4 to the side cover 20b.
3 is sandwiched between the end faces of the union 24 and the spacer 18, and the valve case 23 has a cylindrical shape, and has a spring 25 whose one end abuts the spacer 18 and the other end of the spring 18 to hold the valve. A valve 26 is provided that is pressed against the inner end surface of the case 23 on the union side.

Three 7φ holes 27a to 27C (27b and 270 are not shown) are provided through the circumferential surface of the valve case 23 to communicate the low pressure chamber 21b with the inside of the valve case.

The valve 26 has a cylindrical portion 26A having a cylindrical peripheral surface 26a that slides on the inner peripheral wall of the valve case 23, a hole 26b for refrigerant circulation in the center, and a bottom surface around the hole 26b that receives the dynamic pressure of the sucked refrigerant. 26C and a bottom wall 26B.

When the dynamic pressure of the refrigerant flow applied to the bottom surface 26C of the valve 26 increases beyond the initial load of the spring 25, the barb 25 is compressed and the valve 26
moves to the left of the drawing. This causes the aspect 26 of the valve 26 to
a partially closes the holes 27a to 27C of the valve case 23, reducing the opening area.

The operation of the swash plate compressor of this embodiment constructed as above will be explained in detail below.

When the shirt 1 rotates due to the rotation of the engine transmitted through the electromagnetic clutch 30, the swash plate 3 swings 2 within the space 14.

As the swash plate 3 swings, a well-known double-headed piston (not shown) reciprocates within three pairs of cylinder bores arranged in parallel and at equal intervals around the shaft.

A portion of the refrigerant introduced from the suction union 24 passes through the shaft hole 2 into the cylinder located on the front side across the swash plate 3, and passes through the radial holes 6a, 6b, and 7a.

7b or through holes 8a to 8c and 9a to 9C respectively to thrust bearings 4 and 5 and through holes 10a to 10e and l.
Passing through la-lie, space 14. Oil separation chamber 31a, through hole 32. Through hole 33 provided in the front side plate 19a. The air is sucked in as shown by the arrow through the low pressure chamber 21a in the front side cover 20a where the shaft seal 34 is disposed.

The refrigerant compressed within the front cylinder bore is discharged into the front high pressure chamber 35a, passes through the high pressure pipe 36, and is collected into the rear high pressure chamber 35b.

On the other hand, the remainder of the refrigerant introduced from the suction union 24 is sucked into the cylinder located on the rear side across the swash plate 3 through the through holes 27a to 27C of the valve case 230 and the low pressure chamber 21b.

The refrigerant compressed within the rear cylinder bore is discharged to the rear high pressure chamber 35b, and is discharged from a discharge union (not shown) together with the compressed refrigerant sent from the front high pressure chamber 35a.

A predetermined amount of lubricating oil is mixed in the suction refrigerant, and the oil, which is more viscous than the refrigerant, separates from the refrigerant when the refrigerant passes through the thrust bearing 4.5 and adheres to the sliding parts. Lubricate 5.

The oil in the refrigerant spouted out from the through holes 10a to 10e and lla to lie along the swash plate surface causes the refrigerant to diffuse into the space 14,
While the liquid tends to flow toward the low pressure chamber, it mostly falls onto the swash plate surface, 3A.

Lubricate 3B.

The lubricated oil is scattered in the space by the rotation and oscillation of the swash plate, and a part of it is sent to the low pressure chamber 21 along with the refrigerant flowing in the space 14.
The refrigerant is sucked into the cylinder through the refrigerant a, is discharged into the refrigeration cycle together with the compressed refrigerant, and returns to the suction union 24 in a cooled state.

In this embodiment, oil is supplied by suction refrigerant to the parts of the compressor that require the most lubrication at the same time as the compressor is started, so the lubrication performance at the time of start-up is extremely high.

Furthermore, even if the sliding parts become high in temperature due to frictional heat such as during high-speed rotation, the sliding parts are cooled and lubricated by the low-temperature suction refrigerant, so even under such conditions, effective lubrication can be achieved with a small amount of oil.

What is particularly important is that the through holes 10.a to 10e and 11a to
As shown in FIG. 2, the refrigerant ejected from the refrigerant is deflected in a direction opposite to the direction of rotation of the swash plate 3, and thus receives resistance to the ejection.

The higher the rotation of the swash plate 3, the greater the resistance experienced during this jetting, and as a result, the amount of jetted refrigerant does not change much in a low speed region, but it decreases significantly as the rotation speed increases. Originally, the volumetric efficiency of a compressor tends to decrease as the rotation speed increases, but if the amount of suction refrigerant is actively restricted as in this example, the rate of change in volumetric efficiency will be lower than that of conventional volumetric efficiency. be larger than the proportion.

Therefore, like compressors used in automobile air conditioners, the discharge capacity increases depending on the engine rotation speed, and there is a phenomenon in which the compressor discharges more refrigerant than the amount of refrigerant required by the air conditioner. When used in a compressor, it is possible to automatically suppress the volumetric efficiency of the compressor and reduce the discharge capacity as the engine speed increases, thereby reducing wasteful work of the compressor.

In this embodiment, since a valve mechanism is further provided to control the amount of refrigerant flowing into the rear cylinder, the capacity control effect is even more remarkable.

That is, when the rotation speed of the compressor increases and the discharge amount of refrigerant increases, the flow of refrigerant flowing into the compressor through the suction union 24 becomes faster, and the dynamic pressure of the refrigerant flow acting on the pressure receiving surface 26C of the valve 26 increases. rises. With this increase in dynamic pressure, the valve 26
The spring 25 is compressed toward the left 95 in the drawing, and the peripheral surface 26a closes the through holes 27a to 27C.

As a result, the amount of refrigerant sucked into each cylinder on the rear side decreases, and the amount of refrigerant discharged decreases.

In this embodiment, these two capacity control effects are synergized to obtain an ideal capacity control effect.

In addition, in the above explanation, it was explained that the valve 26 closes a part of the openings 27a to 27C, but the spring 25 is configured to be held inside the spacer 18 so that the valve 26 can move to the left end of the valve case 23. It is also possible to do this, and in this case, the rear cylinder does not take in any refrigerant and is in a closed operation state, eventually reducing the capacity to half of its normal capacity.

Further, the valve 26 is not limited to this embodiment, and a solenoid valve may be used. At this time, the solenoid valve can be controlled not by the dynamic pressure of the refrigerant but by the rotational speed of the compressor or engine.

In this embodiment, the refrigerant flow rate control mechanism for each cylinder on the rear side and the front side is separate. A through hole 331 is provided through the wall of the side oil separation chamber 31b, and is further provided in the rear side plate 19b.
The refrigerant is eventually sucked into the rear cylinder through the shaft hole 2. as shown by the broken line arrow. Space 141 through holes 32b, 33b
It can also be done via .

The present invention will be explained in detail based on the characteristic diagram shown in FIG.

This characteristic shows how the volumetric efficiency of the compressor decreases as the rotation speed of the compressor increases. Characteristics of a conventional swash plate compressor with distributed suction, line m represents the characteristics of this embodiment, and line n represents the characteristics when the suction passage to the rear cylinder is configured as shown by the broken line in Figure 1. show.

Lines m and (1) each have a steep slope indicating the rate of change in volumetric efficiency with respect to line t, indicating that the effect of capacity control becomes greater as the rotation speed becomes higher than in the conventional case.

It can be seen that according to this example, the volumetric efficiency can be effectively suppressed as the rotational speed increases while obtaining a high efficiency similar to the conventional one in the low-speed rotation range.

Looking at this, even though the passage length to the front cylinder has increased by the amount of the shaft hole, the suction passage length to the rear cylinder is short, and there is little passage loss on the rear side, and the overall result is the same as before. It is thought that this is due to the passage loss. On the other hand, in the other embodiment described above having the characteristic shown by the line n, the passage loss through the coaxial holes of both rear cylinders acts to reduce the volumetric efficiency as a whole. It is thought that there are. In this embodiment, the effect of suppressing the volumetric efficiency at high speeds is large in terms of its absolute value, and therefore it is suitable when efficiency at low speeds is not so much of an issue and only capacity suppression at high speeds is required.

Furthermore, if a marked groove is carved at the entrance of the shaft hole 2 to push back the fluid flowing into the shaft hole 2, as shown in FIG. It becomes possible.

Next, an embodiment in which the present invention is applied to a radial compression tower disclosed in Japanese Patent Application Laid-open No. 56-141079 will be described with reference to FIG.

The basic structure and operation of the compressor is disclosed in Japanese Patent Application Laid-Open No. 56-141079.
Since it is the same as the number, the explanation will be omitted.

A shaft hole 52 is bored in the center of the shaft 51 from the rear end toward the front side. The shaft hole 2 is the crank chamber 5
4 through holes 56a to 56d (56b, 56
d (not shown) communicates with the crank chamber 54.

The suction union 53 is screwed into a position facing the shaft hole 52 of a side cover 58 that supports a bearing 57 on the rear side.

The operation of the radial compressor configured in this manner will be described below.

Shaft hole 52 of shaft 51 rotating from suction union 53
The refrigerant that has flowed into the crank chamber 54 is ejected into the crank chamber 54 through the through holes 56a to 56d.

The refrigerant that has flowed into the crank chamber 54 is transferred to the pistons 59a-59.
d (59C, 59d are not shown) suction valve mechanism 608~
60d (60C, 60d are not shown) into the cylinders a1a--61d (61C, 61d are not shown), and after being compressed, the annular high pressure chamber 62
is discharged.

While the rotation of the shaft 51 is low, the refrigerant ejected from the through holes 56a to 56d does not receive much resistance;
When the 0 rotation becomes high, the traveling direction of the ejected refrigerant is sharply deflected, and the refrigerant encounters a large resistance when ejecting.

As a result, the outflow amount decreases as the shaft rotation increases,
Similar to the above-mentioned embodiment, the volumetric efficiency can be suppressed in accordance with the rotational speed.

Next, an embodiment in which the present invention is applied to a rotary vane type compressor disclosed in JP-A-51-89205 will be described with reference to FIG.

The basic configuration and operation of the compressor are the same as those in Japanese Patent Application Laid-Open No. 51-89205, so the explanation will be omitted.

A shaft hole 72 is bored in the center of the shaft 71 from the rear end toward the front side. The shaft hole 72 extends to a low pressure chamber 74 formed in the side cover 73, and four through holes 75a of 5φ are bored there in the radial direction.
75d (75c.

75d (not shown) communicates with the low pressure chamber 74.

The rear end of the shaft 71 extends to the entrance of a suction passage 77 formed in the rear side plate 76. The outlet of the suction passage 77 is opened at the inner end surface of the rear side plate 76 and is connected to the circumferential surface of the rotor 78, the inner circumferential surface of the casing 79, and the inner end surfaces of the front side plate 80 and the rear side plate 76. and vanes (not shown)
The working chamber 81 (corresponding to the cylinder of the above-mentioned compressor) is surrounded by and communicates with the working chamber 81 (corresponding to the cylinder of the above-mentioned compressor), the volume of which changes with the rotation of the vanes, during the suction process.

The operation of the rotary vane compressor configured in this way will be explained below.

The refrigerant that has flowed into the low pressure chamber 74 from the suction port 82 flows into the shaft hole 72 through the through holes 75a to 75d of the rotating shaft 71. The shaft seal 83 is lubricated by lubricating oil mixed into the refrigerant in the low pressure chamber.

The refrigerant that has flowed into the shaft hole 72 is introduced into the working chamber 81 from the rear end of the shaft hole 71 through the suction passage 77 . When one working chamber 81 completes the suction process, communication with the suction passage 77 is cut off, and the chamber becomes a sealed chamber.

The volume of the sealed chamber is reduced by the rotation of the vanes, so that the refrigerant in the sealed chamber is compressed. When the vane rotates by a predetermined angle, the sealed chamber is communicated with the discharge boat 84, and the compressed refrigerant is discharged from the discharge valve 85. Discharge chamber 8 through discharge passage 86
7 and flows out into the refrigeration cycle from a discharge port (not shown).

While the rotation of the shaft 71 is low, the passage from the low pressure chamber 74 to the through hole 75
The refrigerant flowing into the holes 8 to 75d flows smoothly, but when the rotation of the shaft 71 increases and the moving speed of the through holes 75a to 75d increases, the flow rate of the refrigerant at the inlet of the through holes 75a to 75d increases. It cannot keep up with the moving speed, and the refrigerant flowing into the shaft hole 72 becomes diluted. As a result, the amount of suction refrigerant is substantially reduced and the volumetric efficiency decreases with increasing rotational speed.

〔Effect of the invention〕

As explained above, according to the present invention, when refrigerant is sucked into the cylinder, the refrigerant is fed through the shaft hole drilled in the center of the compressor shaft, and the through holes are drilled in the radial direction with respect to the shaft hole. Since the refrigerant is allowed to flow in or out through the shaft, the amount of refrigerant drawn into the cylinder substantially decreases as the shaft rotational speed increases, and as a result, the volumetric efficiency can be reduced as the shaft rotational speed increases. .

Therefore, even in a compressor that is directly rotated by the rotational force of an automobile engine, the compressor does not discharge excess refrigerant when the engine rotates at high speed, so no wasted energy is consumed.

[Brief explanation of drawings]

, FIG. 1 is a sectional view showing an example of a swash plate compressor to which the present invention is applied, FIG. 2 is a sectional view taken along the line ■-■ in FIG.
FIG. 4 is a characteristic diagram showing the relationship between the volumetric efficiency and the rotation speed of the compressor in the embodiment shown in FIG. 1, and FIG.
a) and (b) are drawings for explaining an alternative to the embodiment shown in Fig. 1, Fig. 6 is a sectional view showing an example of a radial compressor to which the present invention is applied, and Fig. 7 is a drawing to which the present invention is applied. Rotary vane type compression height 20 IJ No. 3 (21 pressure regeneration NCCYP electric) 5 days 6 days

Claims (1)

[Claims] 1. In a compressor that is rotationally driven by an automobile engine and sucks and compresses refrigerant circulating in a refrigeration cycle of an air conditioner, the rotating shaft of the compressor is formed hollow, and the rotating shaft is The low-pressure refrigerant of the refrigeration cycle is sucked into the cylinder of the compressor through the hollow part, and the refrigerant passing through the hollow part flows in or out through holes bored in the radial direction with respect to the hollow part. A compressor for an automotive air conditioning system configured as follows. 2. A compressor for an air conditioner for an automobile according to the invention as set forth in claim 1, wherein the compressor comprises the following: (a) 7 cylinders (b) A piston rt that slides into the cylinder. A rotating swash plate that is fixed to the rotating shaft of the compressor and converts the rotational motion of the rotating shaft into reciprocating motion of the piston along the rotating shaft. ) A shaft hole drilled in the rotating shaft, with one end opening at the shaft end and the other end opening toward the swinging space of the rotating swash plate (rumor). (c) Refrigerant introducing means for guiding low-pressure refrigerant from the line; (c) refrigerant passage for guiding the low-pressure refrigerant flowing out from the other end through the shaft hole to the cylinder via the rocking space of the swash plate; (g) discharge from the cylinder. Refrigerant deriving means 3, 4?ff for guiding the compressed refrigerant to the high pressure line of the refrigeration cycle The piston is configured as a double-headed piston that slides into the pair of cylinders, and one of the cylinders that configure the pair of bores has a refrigerant passage that guides the refrigerant flowing out from the shaft hole, and the pair of cylinders is configured such that a refrigerant passage is provided in one cylinder that configures the pair of bores. A compressor for an air conditioner for an automobile, characterized in that the other cylinder is connected to another refrigerant passage that diverts a part of the refrigerant flowing into the shaft hole and directly guides the refrigerant to the bore. 4. Claims The invention set forth in item 3 is characterized in that a valve mechanism is provided at a branch point of the another refrigerant passage to limit the branching of the refrigerant to the other refrigerant passage in response to an increase in engine speed. A compressor for an air conditioner for an automobile. 5. In the invention set forth in claim 1, the compressor for an air conditioner for an automobile is characterized in that the compressor comprises the following: ) Cylinder (→ Piston that slides into the cylinder (U) A crank mechanism that reciprocates the piston in a direction perpendicular to the rotation shaft by the rotational movement of the rotation shaft of the compressor) A cylinder that is bored in the rotation shaft and has one end (E) A shaft hole (e) whose shaft hole opens at its shaft end and whose other end opens into a crank chamber surrounding the crank mechanism; a refrigerant introducing means for guiding low-pressure refrigerant from a low-pressure line with a refrigeration cycle to the shaft end opening of said shaft hole; (F) A refrigerant passage that guides the low-pressure refrigerant flowing out from the other end through the shaft hole into the cylinder via the crank chamber. (G) A refrigerant passage that guides the compressed refrigerant discharged from the cylinder to the high-pressure line of the refrigeration cycle. Deriving means 6, in the invention set forth in claim 1, a compressor for an air conditioner for an automobile, characterized in that the compressor consists of the following: (a) a sealed casing; (b) a rotating shaft; (c) a rotor that is fixed to the rotor and rotates within the casing; a plurality of working chambers surrounded by vanes and whose volumes change as the vanes advance and retreat; (e) bored in the rotating shaft;
A refrigerant passage that connects the shaft end opening of the shaft hole and the working chamber, one end of which opens at the shaft end and the other end of which opens into a low pressure chamber connected to the low pressure line of the refrigeration cycle. g) A low-pressure refrigerant is sucked into the working chamber through the refrigerant passage while the volume of the working chamber is increasing, and a low-pressure refrigerant is sucked into the high-pressure chamber connected to the high-pressure line of the refrigeration cycle while the volume of the working chamber is decreasing. a suction/discharge mechanism that discharges compressed refrigerant from the working chamber;