JPH09228948A - Swash plate type compressor having fixed displacement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the damage which is given to parts when a clutch is turned on and off and provide a swash plate type compressor having a fixed capacity with durability by holding a swash plate in a condition in which it is inclined for an axial line of a shaft after it is inclined for the axial line of the shaft due to the rotation of the shaft. SOLUTION: When an engine rotates, a pulley P rotates through a belt, and the rotation of the pulley P is transmitted to a shaft 1 if an electromagnetic clutch c is on. A rotary arm 26 rotates in accordance with the rotation of the shaft 1, and a swash plate 2 also rotates through a hinge mechanism k. When the operation of a compressor is stopped, suction pressure is not introduced into a crank chamber 3 from a communicating passage 63. The swash plate 2 is springed by springs B1 and B2 through a spherical bush 28 and enters a destroke condition. When the clutch is turned on again to start the operation, this compressor starts from the destroke condition. In this way, it is possible to reduce the damage which is given to internal parts when the clutch is turned on and off and provide the compressor with durability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a so-called fixed swash plate compressor in which a discharge amount of a refrigerant or the like is a predetermined amount.

[0002]

2. Description of the Related Art Conventionally, a swash plate type compressor used in an air conditioner for an automobile has a fixed displacement type in which the inclination angle of the swash plate is fixed with respect to the shaft and a discharge amount of a refrigerant or the like is fixed. On the other hand, there is a variable capacity type in which the inclination angle of the swash plate is changed and the discharge amount of the refrigerant or the like is variable.

All of these compressors are connected to an engine, which is a drive source, via a clutch, and the clutch is discontinued during the cooling operation so that an appropriate amount of refrigerant circulates in the cooling cycle. In order to further improve the efficiency, the control type uses a control valve to control the amount of discharged refrigerant.

Therefore, these compressors have completely different structures depending on whether the swash plate is fixed to the shaft or swingably supported.
In addition, the production line is separate when producing this.

Here, the variable displacement swash plate compressor is
There are various types, for example, the one shown in FIG. 2 proposed by the applicant (see Japanese Patent Application No. 8-339239).
As for the variable displacement compressor, a cylinder block 21 is housed in a tubular case 20, a rear housing 20r is provided on the right end side of the tubular case 20, and a front housing 20f is provided on the left end side thereof. The housings 20r and 20f are connected by a bolt V.

A through hole 23 for inserting the shaft 1 is formed in the center of the front housing 20f, and a radial bearing 24 for rotatably supporting the shaft 1 is press-fitted into the through hole 23. An oil seal 25 is also arranged near the radial bearing 24.

A crank chamber 3 is defined between the inner wall of the front housing 20f and the cylinder block 21, and the shaft 1 in the crank chamber 3 is located near the front housing.
A hinge mechanism K that transmits the rotation of the shaft 1 to the swash plate 2 is provided.

The swash plate 2 is provided so as to be tiltable with respect to the axis of the shaft 1, and has a journal portion 2a and a flat plate portion 2b.
Are separately formed and are connected by a screw portion N. Further, in the hinge mechanism K, the base end is fitted to the shaft 1 and the distal end portion 26a is provided with a long hole 26b, and the rear end of the journal portion 2a of the swash plate 11 is connected to the distal end portion 26a of the rotary arm 26. The long hole 2 projected toward
The driven arm 29 is provided with a hole corresponding to 6b, and the pin 30 is inserted through the elongated hole 26b.

A spherical bush 28 repelled by springs B1 and B2 is provided on the shaft 1 so as to be slidable on the shaft 1 in the axial direction, and the swash plate 2 is supported by the spherical bush 28. The spherical surface of the spherical bush 28 opposes the inner peripheral surface of the central hole O formed at the center of the journal portion 2a of the swash plate 2, and the journal portion 2a and the spherical bush 28 extend from the journal portion 2a to the spherical bush 28. Are connected by a pair of pins 31 protruding along the central axis of the. Therefore, the swash plate 2 has the shaft 1
It is possible to rotate about the pin 31 while being rotated by. "31t" is a thrust bearing,
"31r" is a radial bearing and "32" is a thrust bearing.

A plurality of pistons 6 are provided on the swash plate 2. The swash plate 2 and the pistons 6 are connected by sliding shoes 4 and 5, respectively. It is designed to be converted into motion.

A suction port 35 for sucking the refrigerant and a discharge port 36 for discharging the refrigerant are formed on one end surface of the silicidator chamber 7, and the refrigerant flows through the suction port 35 and the discharge port 36. A valve plate 39 including valve forming plates 37 and 38 having a plurality of intake valves and discharge valves for controlling the above is provided.

The return refrigerant from the evaporator flows into the suction port 35 through the suction chamber 40 formed in the rear housing 20r, and is formed in the valve forming plate 37 on the left side of the valve plate 37 in the figure. Further, it flows into the cylinder chamber 7 in the suction process against the elastic closing force of the suction valve. Further, the refrigerant compressed by the piston is discharged to the discharge port 36 against the elastic closing force of the discharge valve formed on the valve forming plate 38 on the right side of the valve plate 37 in the figure, and this refrigerant is The discharge port 36 leads the discharge chamber 41.

Further, a control valve Cv for adjusting the pressure condition in the crank chamber 3 and adjusting the inclination angle of the swash plate 2.
Is installed in the rear housing 20r. The control valve Cv adjusts the pressure in the crank chamber 3 according to the suction pressure of the returning refrigerant to change the angle of the swash plate 2 to adjust the amount of refrigerant discharged from the compressor.
It controls the suction pressure of the compressor to be constant.

For example, an electromagnetic clutch (not shown) is turned on,
When the shaft 1 is rotated by an engine (neither is shown) via the belt and the pulley, the rotating arm 26 rotates accordingly, and the swash plate 2 also rotates via the hinge mechanism K. When the swash plate 2 is tilted with respect to the shaft 1, the swash plate 2 pivots in a grazing motion, and the piston 6 reciprocates accordingly, so that the suction port 35 sucks into the cylinder chamber 7. The discharged refrigerant is compressed and discharged from the discharge port 36 into the discharge chamber 41.

The heat load in the cooling cycle is
When the temperature is higher than the preset temperature, a relatively high suction pressure is introduced into the crank chamber 3 by the action of the control valve Cv. Therefore, since the internal pressure of the crank chamber 3 becomes substantially equal to the suction pressure, there is almost no pressure difference between the front and rear of the piston 6 in the suction process, and the piston 6 can be smoothly retracted in the cylinder chamber 7. The inclination angle of the swash plate 2 increases and the stroke of the piston 6 increases.

When compression is performed in this state, the amount of discharged refrigerant increases, the flow rate of the refrigerant circulating in the cooling cycle increases, and a proper flow rate of the refrigerant corresponding to the heat load is discharged. As a result, the heat load is reduced, the suction pressure of the compressor is gradually lowered, and the suction pressure is finally kept constant.

When the heat load in the cooling cycle is reduced or the compressor is rotated at a high speed to cause an excess of the refrigerant, the pressure of the return refrigerant is not sufficient to obtain a superheat amount, and the refrigerant is returned at a low pressure and the suction chamber 40 The pressure of becomes low.

In such a case, by the action of the control valve Cv, the high-pressure refrigerant compressed by the piston 6 and guided to the discharge port 36 is introduced into the crank chamber 3 and the internal pressure of the crank chamber 3 is increased. . As a result, the moment of the force applied to each of the plurality of pistons 6 centering on the pin 30 is different, and the inclination angle is reduced.

That is, M1 is a moment acting clockwise about the hinge mechanism K generated by the reaction force due to compression, M2 is a moment acting counterclockwise generated by the repulsive force of the spring B1, M3 is , Moment generated by the pressure difference between the crank chamber 3 and the suction chamber 40, these moments are M1 <M2 + at some point.
It becomes M3.

As a result, the inclination angle of the swash plate 2 becomes small,
As a result, when the stroke of the piston 6 is shortened, the amount of discharged refrigerant is reduced, and the suction pressure is finally kept constant.

As described above, the variable capacity compressor is
Since the discharge amount of the refrigerant is controlled by the heat load, the number of clutch engagements and disengagements is small and the operating efficiency is good. Therefore, it has been widely used recently and is becoming the mainstream.

On the other hand, the fixed capacity swash plate compressor is well known, and although detailed description thereof will be omitted, the swash plate is rotated while the swash plate is fixed to the shaft at a predetermined angle. The piston attached to the cylinder compresses the refrigerant by linearly reciprocating in the bore of the cylinder.The discharged refrigerant is controlled by turning on and off the clutch that connects the engine and the swash plate compressor. I am supposed to do it. (See, for example, Japanese Patent Laid-Open No. 5-133325, etc.) This fixed displacement type swash plate compressor is slightly lower in performance and efficiency than the variable displacement swash plate type compressor, but it is still inexpensive, so it is still present. The fact is that it is being used.

[0023]

However, both types of compressors have advantages and disadvantages. First, the variable displacement swash plate type compressor uses expensive parts such as a control valve and has a large number of parts, so that the cost is high.

On the other hand, in the fixed capacity swash plate compressor, since the swash plate is fixed to the shaft, the amount of discharged refrigerant is controlled by turning the clutch on and off, but the operation is stopped by turning the clutch on and off. When the state changes from the operating state to the operating start state, the refrigerant, etc. is suddenly compressed, so the pressure fluctuation inside the compressor is large, and sudden force is applied to the internal parts of the compressor, or this is released. Such a state always occurs when the clutch is turned on and off, and as a result, the damage given to the internal parts becomes considerably large, and there is a problem in terms of durability. Further, although liquid compression may be performed, in this case, since the operation is performed with a full stroke from the start of the operation, a shock at the start of the operation is large and an abnormal noise may be generated.

Furthermore, both types of compressors are currently produced on independent production lines due to the difference in structure, but if they are produced on independent production lines in this way, equipment Since the cost is high and it is difficult to share the parts of both compressors, it is difficult to significantly reduce the cost of the product.

The object of the present invention was made in view of the above-mentioned problems of the prior art. Although it is a swash plate type compressor having a fixed capacity in terms of function, it does not damage the parts when the clutch is turned on and off. It is durable, has no shock during liquid compression, and can be shared with variable capacity compressors and can be manufactured on the same production line. It is to provide a plate compressor.

[0027]

In order to achieve the above object, the present invention as set forth in claim 1, is a cylinder block in which a plurality of cylinder chambers are formed, and a crank chamber or a suction chamber connected to the cylinder block. A housing formed to form a shaft, a shaft that is provided so as to pass through the crank chamber and through which a rotational force from a drive source is transmitted via a clutch, and that is disposed in the crank chamber and tiltable with respect to the axis of the shaft. A swash plate provided on the swash plate, a rotation transmission mechanism that transmits the rotation of the shaft to the swash plate, a plurality of pistons that are linearly reciprocally movable in the cylinder chamber, and a swash plate swaying rotary motion. In a swash plate compressor having a connecting mechanism that connects the swash plate and the piston so as to convert the swash plate into a reciprocating linear motion of Ri After tilting the axis of the shaft, the inclined state is characterized in that so as to be retained.

In the present invention thus constructed, the basic construction is the same as that of the variable capacity compressor,
Functionally, it is a fixed-capacity type compressor, so it is possible to achieve a large share of parts and production lines, and a swash plate compressor that is extremely cost effective. Moreover, unlike the conventional fixed swash plate compressor, since the operation is started from the destroke state, there is little damage to the internal parts during on-off and it is durable, and shocks and differences such as during liquid compression occur. It is a swash plate compressor with a fixed capacity and low noise.

The invention according to claim 2 is characterized in that the suction chamber and the crank chamber are directly communicated with each other through a communication passage.

In this swash plate compressor, since the front-rear pressure of each piston, that is, the pressure in the crank chamber and the pressure on the piston crown side are the same at the time of starting, the swash plate is in a slightly inclined state. When the operation is started, the suction pressure is introduced into the crank chamber through the communication passage, so that the pressure difference before and after each piston becomes large, the swash plate is inclined, and the piston is operated with a full stroke. Then, if the operation causes an excessive amount of refrigerant in the cooling cycle, the clutch is disengaged and the rotation of the shaft is stopped. Therefore, the swash plate type compressor has the same configuration as that of the variable displacement compressor, and the swash plate compressor operates normally without using the control valve of the variable displacement compressor.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a swash plate type compressor with a single head and a fixed capacity according to an embodiment of the present invention. The same members as those shown in FIG. 2 are designated by the same reference numerals, and the description thereof is partially omitted. To do.

The swash plate type compressor having a fixed capacity shown in FIG. 1 will be outlined. The control valve Cv of the swash plate type compressor having a variable capacity described above is abolished, and the suction chamber 40 and the crank chamber 3 are connected by a communication passage 43. Electromagnetic clutch C
Is provided, and the operation control is performed by the electromagnetic clutch C.

The fixed capacity swash plate compressor has a cylindrical case 20, and a through hole 23 is formed in the center of a front housing 20f provided on the left end side of the cylindrical case 20. The shaft 1 is rotatably supported in the through hole 23, and an electromagnetic clutch C is provided at an end of the shaft 1.
Is provided. The electromagnetic clutch C intermittently transmits the rotation of the pulley P, to which the rotational force of the engine is transmitted via the belt, to the shaft 1.
The rotation of the engine is transmitted to the engine via a belt (not shown).

The shaft 1 is inserted through the crank chamber 3, and the end of the shaft 1 is rotatably supported in the center hole 21a of the cylinder block 21 via a radial bearing 31r. The swash plate 2 is attached to the inner portion so as to be tiltable via a rotation transmission mechanism. The rotation transmission mechanism of this embodiment is preferably the hinge mechanism K described above. In other words, in the swash plate compressor according to the present embodiment, it is desirable that the swash plate 2 and its support mechanism have the same configuration as that of the variable capacity type in terms of production or cost even if the capacity is fixed. Therefore, the above-mentioned hinge mechanism K is used.

Plural pistons 6 are provided on the swash plate 2, and the swash plate 2 and the individual pistons 6 are connected by a connecting mechanism. The connecting mechanism may be any one as long as it connects the swash plate 2 and the piston 6, but for example, sliding shoes 4 and 5 as shown in the drawing can be used.

The sliding shoes 4 and 5 are flat surfaces 4a and 5a which are finished so as to slide on the flat portion 2b of the swash plate 2 and spherical concave portions 9s and 10s of the connecting portions 9 and 10, respectively. It has spherical convex surfaces 4b and 5b which are fitted in concave and convex, and is adapted to convert the rubbing rotary motion of only the swash plate 2 into the reciprocating linear motion of the piston.

The swash plate 2 and the piston 6 may be connected not only directly by the sliding shoes 4 and 5, but also via a connecting rod having a spherical portion at the end.

The shaft 1 has a spherical bush 28.
Although springs B1 and B2 that repel the swash plate are provided, in the case of a fixed capacity swash plate compressor that fixes the tilted state of the swash plate 2 to the maximum tilt, the swash plate is completely perpendicular to the axis of the shaft 1. Therefore, the spring B1 may be eliminated and the spherical bush 28 may be repelled only by the spring B2.

A suction port 35 for sucking the refrigerant and a discharge port 36 for discharging the refrigerant are formed at one end surface of the silicidator chamber 7, and the refrigerant flows to the suction port 35 and the discharge port 36. A valve plate 39 including valve forming plates 37 and 38 having a plurality of intake valves and discharge valves for controlling the above is provided.

The return refrigerant from the evaporator flows into the suction port 35 through the suction chamber 40, and the elastic return force of the suction valve formed on the valve forming plate 37 on the left side of the valve plate 37 in the figure is applied. On the contrary, the gas flows into the cylinder chamber 7 in the suction process. Further, the refrigerant compressed by the piston is discharged to the discharge port 36 against the elastic closing force of the discharge valve formed on the valve forming plate 38 on the right side of the valve plate 37 in the figure, and this refrigerant is The discharge port 36 leads the discharge chamber 41.

In particular, in the present embodiment, the suction chamber 40 and the center hole 21a of the cylinder block 21 are communicated with each other by the communication passage 43, and the piston 6 is compressed by this communication passage 43 and the suction port is discharged from the discharge port 36. The refrigerant guided to 40 flows into the crank chamber 3.

Next, the operation of the embodiment will be described. First, a special assembly line is not required to assemble a fixed capacity swash plate compressor, and a conventional variable capacity swash plate compressor assembly line is used.

For example, first, the hemispherical convex surfaces 4b, 5b of the sliding shoes 4, 5 are fitted to the spherical concave surfaces 9s, 10s of the connecting portions 9, 10 formed at the rear end of the piston 6, and the sliding shoes are made. The flat portion 2b of the swash plate 2 is attached between the points 4 and 5.

Next, the flat portion 2b of the swash plate 2 and the journal portion 2a are connected by the screw portion N. In this way, the sliding shoes 4, 5 can be easily attached without dropping from between the piston 6 and the swash plate 2.

Then, the driven arm 29 protruding from the back surface of the journal portion 2a of the swash plate 2 and the rotary arm 26 are connected by inserting the pin 30 into the elongated hole 26b to assemble the portion of the hinge mechanism K.

After the assembly having the piston and the like thus formed and the shaft 1 are assembled in the cylinder block 21, the tubular case 20 and the front housing 2 are formed together with the valve forming plates 37, 38 and the valve plate 39.
The assembly is completed when it is assembled to 0f or the rear housing 20r.

Assembling of the variable capacity swash plate compressor is such that the main part of the compressor is assembled in this way, and the control valve Cv for adjusting the pressure state in the crank chamber 3 and adjusting the inclination angle of the swash plate 2 is used. However, the fixed capacity swash plate compressor does not have such a control valve Cv, and most of the configuration is the same as that of the variable capacity swash plate compressor. It can be assembled using a plate compressor assembly line, eliminating the need for a special assembly line.

Therefore, there is a convenience that both types of compressors can be mixed and assembled and produced in the same line. In addition, parts such as the control valve Cv are unnecessary for the fixed capacity type. Since most of the parts can be shared with the variable capacity type, the product cost can be greatly reduced.

Next, the operating state of the fixed displacement compressor will be described.

When the engine is rotated, the pulley P is rotated via the belt, and when the electromagnetic clutch C is in the ON state, the rotation of the pulley P is transmitted to the shaft 1 and the shaft 1 is rotated. The rotating arm 26 rotates, and the swash plate 2 also rotates via the hinge mechanism K.

In this fixed capacity swash plate type compressor, the swash plate 2 is set to be slightly inclined even in the normal state due to the difference in elastic force of the springs B1 and B2. It rotates kinematically, and accordingly, the piston 6 reciprocates to immediately start compression.

In this case, since the suction pressure is introduced into the crank chamber 3 by the communication passage 43, the internal pressure of the crank chamber 3 becomes substantially equal to the suction pressure. Is almost eliminated, the piston 6 is allowed to smoothly retract in the cylinder chamber 7, the stroke of the piston 6 increases, and the piston 6 operates in full stroke in the cylinder chamber 7, and the swash plate 2 is held in the maximum tilted state. It

If this full stroke operation continues, more than the amount of refrigerant corresponding to the heat load will circulate in the cooling cycle. This is due to, for example, a signal from a sensor or the like which prevents the evaporator from freezing. The electromagnetic clutch C that connects the compressor and the engine is turned off to stop the operation of the compressor. Therefore, even if the control valve Cv is not provided, the compressor operates normally.

When the compressor stops operating, suction pressure is not introduced into the crank chamber 3 from the communication passage 43, so that the swash plate 2 is repelled by the springs B1 and B2 via the spherical bush 28, and the swash plate 2 is repulsed. Stroke state. However, the swash plate 2 is not in a complete destroke state, which is a state that is completely perpendicular to the axis of the shaft 1.

Therefore, when the clutch is turned on again and the operation is started, the compressor is started from the destroke state, so that the internal parts are less damaged and durable when turned on and off. It is a swash plate type compressor that does not generate shock or abnormal noise when compressed.

The present invention is not limited to the above-described embodiments, but can be variously modified within the scope of the claims. For example, in the above-described embodiment, the tilting of the swash plate 2 is fixed to a predetermined tilted state immediately after the rotation of the shaft 1 is started, the control valve is abolished, and production equipment or cost is reduced. The suction chamber 40 and the crank chamber 3 are directly communicated with each other through the communication passage 43. However, the present invention is not limited to this, and a gear pump is provided at the end of the shaft 1 and the hydraulic pressure created by the gear pump causes the shaft to move. 1
The actuating rod extending in the axial direction may be moved forward and backward to actuate the spherical bush 28 in the axial direction to fix the inclination of the swash plate. In some cases, the rotating arm of the hinge mechanism K may be rotated. An electromagnet is attached to the balancer 26, and the balancer portion 4 is projected from the journal portion 2a of the swash plate 2.
5 may be attracted by an electromagnet to fix the inclined state of the swash plate 2.

[0057]

As described above, according to the present invention, although it is a fixed displacement type compressor in terms of function, it has less damage to internal parts when it is turned on and off, and has durability, and moreover, it is a liquid type compressor. Since there is no shock or abnormal noise during compression, and the basic configuration is the same as that of the variable capacity type, parts and production lines can be shared when producing both compressors, which is cost effective. The swash plate compressor is extremely advantageous for

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a fixed capacity swash plate compressor according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of a swash plate type compressor having a variable capacity.

[Explanation of symbols]

1 ... Shaft, 2 ... Swash plate, 3 ... Crank chamber, 4, 5 ... Connection mechanism (sliding shoe), 6 ...
Piston, 7 ... Cylinder chamber, 20f, 20
r ... Housing, 21 ... Cylinder block, 41 ... Discharge chamber, 43 ... Communication passage, C ... Clutch, K ...
Rotation transmission mechanism (hinge mechanism).

Claims (2)

[Claims] 1. A cylinder block (21) having a plurality of cylinder chambers (7) formed therein, and a crank chamber (3) or a suction chamber (40) formed inside the cylinder block (21) connected to the cylinder block (21). It is installed so that the housing (20f, 20r) and the crank chamber (3) are inserted, and the rotational force from the drive source is applied to the clutch.
Shaft (1) transmitted via (C), a swash plate (2) disposed in the crank chamber (3) and tiltable with respect to the axis of the shaft (1), and the shaft (1). ) Is transmitted to the swash plate (2), and a plurality of pistons are installed in the cylinder chamber (7) so as to be linearly reciprocable.
(6) and the swash plate (2) only
(6) A swash plate compressor having a connecting mechanism (4,5) for connecting the swash plate (2) and the piston (6) so as to convert the swash plate (2) into a reciprocating linear motion. A fixed capacity swash plate compressor, characterized in that after the shaft (1) is tilted with respect to the axis of the shaft (1) by rotation, the tilted state is maintained. 2. The suction chamber (40) and the crank chamber (3) are
The fixed capacity swash plate compressor according to claim 1, wherein the swash plate compressor has a direct communication through a communication passage (43).