JPH04143467A - Variable capacity compressor with swinging swash plate - Google Patents

Abstract

PURPOSE:To enhance the effectiveness in assembly work by providing a housing with a guide groove stretching in the axial direction, equipping a swing plate with a guide pin sliding in this guide groove with shoes interposed, and magnetizing these shoes or the guide pin. CONSTITUTION:A guide pin 131 is equipped at the tip with a ball 131a, which is magnetized in advance, and is fixed to one end of a swing plate 13, and a guide groove 12 parallel with a drive shaft 6 is carved in a housing 2 on its crank chamber 5 side. The ball 131a is pinched by a pair of disc-shaped shoes 10, 11 made of magnetic material having spherical concave surfaces 10a, 11a matching with the ball 131a and slide surfaces 10b, 11b matching with the plane of the guide groove 12. When the front housing 2 is put from the driving shaft 6 side at assembling, the shoes 10, 11 are favorably accommodated in the guide groove 12 together with the ball 131a because the shoes 10, 11 are magnetically attached to the ball 131a on the guide pin 131 secured to the swing plate 13.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is characterized in that the inclination angle of the rocking plate is changed by changing the stroke of the piston according to the differential pressure between the crank chamber pressure and the suction pressure. This invention relates to improvements in a variable capacity oscillating swash plate compressor (hereinafter simply referred to as a compressor) in which the compression capacity is controlled, and in particular, to improvements in shoes or guide pins that restrict the rotation of the oscillating plate and improvements in the housing. .

[Prior Art] As a conventional compressor, the one described in Japanese Patent Application Laid-Open No. 63-239380 is known. In this compressor, a front housing and a cylinder block that are joined to each other form a crank chamber, and a drive shaft is rotatably supported within the crank chamber. A swash plate is swingably supported on the drive shaft via a rotor, and the swash plate is rotated at a predetermined inclination angle in response to rotation of the drive shaft. A swing plate is moored to this swash plate via a bearing or the like. A guide bin is fixed to this rocking plate, and when this guide bin slides through an axial guide groove cut into the housing via a pair of shoes, the rocking plate rotates. A piston is moored to this rocking plate via a piston rod, and depending on the tilt angle of the rocking plate, the piston moves into the bore of the cylinder block. The reciprocating movement of the piston forms a compression chamber in the bore.The rear housing, which is connected to the cylinder block, has a suction chamber that introduces fluid into the compression chamber via a valve plate. and a discharge chamber from which compressed fluid is led out from the compression chamber via a valve plate.Furthermore, a bleed passage is formed in the cylinder block to communicate the crank chamber and the suction chamber, and this bleed passage is controlled by an on-off valve housed in the rear housing.

As a result, the stroke of the piston can be changed according to the differential pressure between the crank chamber pressure and the suction pressure, and the inclination angle of the rocking plate is changed to control the compression capacity.

[Problems to be Solved by the Invention] However, this type of compressor has problems both in terms of assembly and compression capacity control.

That is, this compressor is assembled approximately as follows. First, a cylinder block is joined to a rear housing that houses an on-off valve and has a valve plate interposed therebetween. In addition, a swinging plate to which the piston rod and piston are moored and to which a guide bin is fixed is prepared. Then, a rotor is fixed to the drive shaft, a swash plate is moored to the rotor, and a swing plate is moored to the swash plate along with a piston rod and the like. Next, while the piston is accommodated in the bore of the cylinder block, the drive shaft is pivotally supported by the cylinder block along with the rotor and the like. After this, put the front housing on the drive shaft side,
A compressor is installed. When covering the front housing, a pair of shoes are interposed on the guide bin fixed to the swing plate, and the guide bin and the shoes are housed in the guide groove of the housing. This guide bin and each shoe are
Due to the need for both to be rotatably moored and for each shoe to be slidably housed in the guide groove, the guide bin has a spherical ball, and each shoe is provided with a spherical concave surface that aligns with the ball. At the same time, a sliding surface that is aligned with the side surface of the guide groove is formed. At this time, the guide bin and each shoe must be inserted into the guide groove while the ball and each spherical concave surface are aligned and the sliding movement of the shoe is aligned with the side surface of the guide groove of the housing. For this reason, during such work, each shoe may fall off from the guide bin, resulting in deterioration of workability.

In addition, in such a compressor, the stroke of the piston is determined according to the inclination angle of the rocking plate, thereby determining the compression capacity. For this reason, when this compressor is installed in a vehicle air conditioner, for example, in order to obtain a suitable cabin environment under an engine whose rotation speed changes from moment to moment, it is necessary to control not only the air conditioner according to the cooling load. , feedback by the actual tilt angle of the rocking plate is also required. Conventionally, by providing a detected object at a predetermined position on the periphery of the oscillating plate and a detector for detecting a detection signal caused by the passing of the oscillating object in the housing, the rotational speed of the drive shaft and the oscillating plate can be controlled. There is a proposal to detect the angle of inclination (Japanese Patent Application Laid-Open No. 62-218670).
Publication No.). However, such a proposal has the disadvantage that the object to be detected and the detector must be specially provided, leading to a rise in product cost.

The first invention aims to improve the ease of assembly.

In addition, the second invention aims to improve the ease of assembly and improve compression capacity control while preventing a rise in product costs.

[Means for Solving the Problems] In order to solve the above problems, in the compressor of the first invention, a guide groove is formed in the housing in the axial direction, and a guide groove is formed in the rocking plate through a shoe. A novel method is adopted in which the guide pin that slides in the guide groove is fixed, and these shoes or guide pins are magnetized so that they are magnetically attached to each other.

Moreover, in order to solve the above-mentioned problem, the compressor of the second invention adopts a novel means of providing a detection means for detecting the magnetic force of the shoe or the guide pin at a position opposite to the locus of the guide pin in the housing. There is.

[Function] In the compressor of the first invention, since the shoes or guide pins are magnetized to attract each other, when the front housing is placed on the drive shaft side, the guide pins and shoes fixed to the rocking plate are attached to each other. are attracted to each other by magnetic force, and the shoe and the guide pin are suitably accommodated in the guide groove of the housing. Therefore, the shoe will not fall off the guide pin during this operation.

In the compressor of the second invention, the detection means provided in the housing detects the rotational speed of the drive shaft and the inclination angle of the rocking plate by receiving the magnetic force of the shoe or the guide pin. For this reason, when this compressor is installed in a vehicle air conditioner, for example, even under an engine whose rotational speed changes every moment, the rotation of the drive shaft can be detected without engaging or disconnecting the electromagnetic clutch. A suitable vehicle interior environment can be obtained from the number and the inclination angle of the rocking plate.

In this case, since the magnetized shoe or guide pin also serves as the object to be detected, no special object to be detected is required.

[Example] Hereinafter, an example embodying the first and second inventions will be described with reference to the drawings.

In this compressor, as shown in FIG. 1, a front housing 2 is joined to one end face of a cylinder block 1, and a rear housing 4 is joined to the round end face via a valve plate 3. A drive shaft 6 is located in the crank chamber 5 in the front housing 2.
extends rotatably, and a rotor 7 is fixed to this drive shaft 6. A long hole 7b is formed in the rotor 7, and a pin 8a is slidably inserted into the long hole 7b, so that the swash plate 8 is pivotably supported relative to the drive shaft 6. . A bearing 9 and the like are interposed on the swash plate 8, and a sleeve 19 serving as a fulcrum for rocking motion is interposed on the drive shaft 6, by which the wobble plate 13 is anchored. As shown in FIGS. 3 and 4, one end of this swing plate 13 has a spherical ball 131a whose tip is magnetized in advance.
A guide pin 131 having a diameter is fixed thereto. Furthermore, a guide groove 12 is carved in parallel to the drive shaft 6 on the crank chamber 5 side of the housing 2 . This guide groove 12, as shown in FIG. Ball 13 on pin 131
1a is a spherical concave surface 10a, 11 that aligns with the ball 131a.
a, and sliding surfaces 10b and 1 that align with the plane of the guide groove 12.
1b and is held between a pair of circular dish-shaped shoes 10.11 made of a magnetic material. The ball 131a slides in the guide groove 12 via both shoes 10.11, so that the swash plate 13 moves as the swash plate 8 rotates.
performs a rocking motion that depends on the inclination angle of the In addition, the housing 2 has a guide groove 1 as shown in FIGS. 1 and 4.
The guide groove 12 is the passage position of the ball 131a that is C-pull on the bottom surface of the sleeve 12, and is the center position of the swinging movement locus of the ball 131a when the swinging plate 13 is at the minimum inclination angle, that is, the guide groove 12 facing the center 19a of the sleeve 19. A sensor 16 as a detection means is provided on the bottom surface of the sensor. This sensor 16 generates a signal pulse once every time the ball 131a passes (receives the magnetic force of the ball 131a, and supplies this signal pulse to a control unit (not shown).
As shown in FIG. 1, a piston rod 14 is moored to the cylinder block 3, and pistons 15 housed in a plurality of bores 1a of the cylinder block 1 are moored to the piston rod 14. In this way, the piston 15 reciprocates within the bore 1a according to the inclination angle of the rocking plate 13 due to the rotation of the drive shaft 6.

In addition, a suction chamber 17 and a discharge chamber 18 are provided in the rear housing 4.
The refrigerant gas in the suction chamber 17, which communicates with a refrigeration circuit (not shown), is supplied into the bore 1a (supplied into the bore 1a) via the suction valve and the suction boat of the valve plate 3. The compressed refrigerant gas is discharged into the discharge chamber 18 via the discharge port of the valve plate 3 and the discharge valve 18a, and further sent to the refrigeration circuit.

Furthermore, an air supply passage 20 that communicates between the discharge chamber 18 and the crank chamber 5 is formed in the cylinder block 1 and the rear housing 4, and an air bleed passage 21 that communicates between the crank chamber 5 and the suction chamber 17 is formed. ing. Air supply passage 2
A control valve 22, which will be described later, is installed in the middle of the air bleed passage 21, and a safety valve 23, which will be described later, is installed in the middle of the bleed passage 21.

The control valve 22 has a valve main body 2 equipped with a diaphragm 30 in a space formed in the middle of the air supply passage 20 of the rear housing 4.
A valve body 33 is held on the lower surface of the diaphragm 30 and is arranged so as to be able to approach and separate from the valve seat 32 via a support rod 31. A spring 34 is held on the upper surface of the diaphragm 30 by an adjusting screw 35. Adjustably supported.

Therefore, the atmospheric pressure po and the biasing force of the spring 34 act on the upper chamber 22b partitioned by the diaphragm 30. A solenoid 39 connected to a control unit (not shown) is provided in the upper chamber 22b.

In addition, the valve body 22a and the rear housing 4 have a royal 22
A detection passage 37 that communicates between G and the suction chamber 17 is provided. Therefore, a biasing force due to the suction pressure ps acts on this royal chamber 22G. Further, the valve body 33 is disposed with a spring 38 interposed between it and the lower end of the valve body 22a. In this control valve 22, under normal conditions, a constant value of current is applied from the control unit to the solenoid 39, and the sensor 1
The current value is changed based on the signal pulse from 6. In this way, in this control valve 22, the diaphragm 30 is opposed by the atmospheric pressure PO, the biasing force of the spring 34, the suction pressure ps, the biasing force of the spring 36, 38, and the biasing force of the solenoid 39, and changes in the suction pressure ps. The valve body 33 comes into contact with and separates from the valve seat 32 due to the movement of the diaphragm 30 through changes in the current value, so that the air supply passage 20
Open and close.

The safety valve 23 has a valve main body 2 equipped with a diaphragm 40 in a space formed in the middle of the bleed passage 21 of the rear housing 4.
A spool 41 having a slit 41 a is housed in the upper surface of the diaphragm 40 so as to be slidable via a spring 42 , and a spring 4 is housed in the lower surface of the diaphragm 40 .
3 is adjustable and supported by an adjustment screw 44. Therefore, the bleed passage 21 is located on the pressure receiving surface 41b of the spool 41.
Accordingly, the crank chamber pressure PC acts, and the atmospheric pressure PO and the biasing force of the spring 43 act on the royal chamber 23b.

In this way, in this safety valve 23, the diaphragm 40 is opposed by the crank chamber pressure PC and the biasing force of the spring 42, and the atmospheric pressure PO and the biasing force of the spring 43, and a predetermined amount of refrigerant gas is always supplied through the slit 41a of the spool 41. When the crank chamber pressure PC rises, the spool 4
1 moves downward, the slit 41a is enlarged to increase the amount of refrigerant gas flowing out.

This compressor is assembled approximately as follows.

First, the cylinder block 1 is joined to the rear housing 4 which houses the control valve 22 and the safety valve 23 and has the valve plate 3 interposed therebetween. Further, a swing plate to which the piston rod 14 and the piston 15 are moored and to which the guide pin 131 is fixed is prepared. Then, a rotor 7 is fixed to the drive shaft 6, a swash plate 8 is moored to the rotor 7, and a swing plate 13 is moored to the swash plate 8 together with the piston rod 14 and the like.

“Next, the piston 15 is inserted into the bore 1 of the cylinder block 1.
The drive shaft 6 and the rotor 7 etc. are supported by the cylinder block 1 while being housed in the cylinder block 1. After that, the front housing 2 with the sensor 16 attached is placed over the drive shaft 6 side.

When covering the front housing 2, the ball 131a of the guide pin 131 fixed to the swing plate 13 is covered with the front housing 2.
10.11 is magnetically attached. For this reason, guide pin 1
The shoe 10.11 is suitably accommodated in the guide groove 12 of the housing 2 together with the 31 balls 131a. Therefore, in this compressor, the shoe 10.
11 can be easily assembled without falling off from the ball 131a of the guide pin 131.

The compressor configured as described above has the suction chamber 17 and the discharge chamber 18 shown in FIG. 1 connected to a refrigeration circuit, and is used as a vehicle air conditioner. When this compressor is operated, the drive shaft 6
When the swash plate 8 rotates, the swash plate 8 rotates and oscillates together with the drive shaft 6. The swing plate 13 is configured so that the ball 131a of the guide pin 131 is connected to the housing 2 through both shoes 10.11.
Rotation is regulated by sliding in the guide groove 12 of.

As a result, the piston 15 reciprocates within the bore 1a, so that the refrigerant gas in the suction chamber 17 is sucked, compressed, and discharged into the chamber 18.
Discharge to is performed.

At some point, if the heat load is large, the amount of return refrigerant gas is increasing, and the suction pressure PS is high, the support rod 31 of the control valve 22 will rise and the valve body 33 will be seated on the valve seat 32. , from the discharge chamber 18 to the crank chamber 5 via the air supply passage 20
The refrigerant gas at the discharge pressure Pd introduced into the refrigerant is stopped. At this time, if the crank chamber pressure Pc does not become very high due to the proby gas flowing out from the gap between the piston 15 and the bore 1a, the spool 40 will be located at the top dead center in the safety valve 23, and the refrigerant gas in the crank chamber 5 will flow through the bleed passage. 21, is constantly led out to the suction chamber 17 through the slit 41a of the spool 41 and the bleed passage 21. For this reason, piston 1
Since the force acting on the back surface of piston 5 is small, the swing plate 13 does not cause a moment change, and the compressor moves toward the piston 1.
The stroke number 5 is the longest maximum discharge capacity.

At this maximum discharge capacity, the port 131 of the guide pin 131
As shown in FIG. 5(a), a considerable number of signal pulses are generated from the sensor 16 which receives the magnetic force of 6 per unit time. The control unit determines the rotational speed of the drive shaft 6 from the number of signal pulses. In addition, the control unit uses a short time Δ due to the difference in the generation time of each signal pulse.
The difference between t1 and long time Δt2 is eliminated. short time Δt
1, when the ball 131a moves around the guide groove 12 together with the shoe 10.11, the swinging plate 13 swings toward the cylinder block 1, passes the sensor 16, turns around, and swings toward the rotor 7. This is the time it takes to pass the sensor 16. The long time Δ↑2 is the time required for the swing plate 13 to swing toward the rotor 7, pass the sensor 16, turn back, swing toward the cylinder block 1, and pass the sensor 16.

The control unit confirms that the swing plate 13 is at the maximum tilt angle from the difference between the short time Δt1 and the long time Δt2. Then, the control unit applies an optimal current to the solenoid 39 that energizes the support rod 31 based on the rotational speed of the drive shaft 6 and the maximum inclination angle of the swing plate 13. In other words, if there is too much cooling due to high rotational speed,
Reduce the current value, lower the support rod 31, and remove the valve body 33.
is released from the valve seat 32. As a result, refrigerant gas at the discharge pressure Pd is introduced from the discharge chamber 18 into the crank chamber 5 through the air supply passage 20. When the crank chamber pressure PC increases due to the addition of the proby gas, the force acting on the back surface of the piston 15 is large, causing a moment change in the rocking plate 13, and the compressor gradually reduces its discharge capacity.

Finally, as shown in Fig. 2, the piston 1
A stroke of 5 is the shortest minimum discharge capacity.

At this minimum discharge capacity, the ball 13 of the guide pin 131
As shown in FIG. 5(b), the sensor 16 receiving the magnetic force of 1a generates a considerable number of signal pulses during a unit time of 6 pulses. The control unit determines the rotational speed of the drive shaft 6 from the number of signal pulses, and also determines the difference between the short time Δt1 and the long time Δt3 from the difference in time of generation of each signal pulse. The control unit confirms that the swing plate 13 is at the minimum tilt angle from the difference between the short time Δt1 and the long time Δt3.

Based on the rotation speed of the drive shaft 6 and the minimum inclination angle of the rocking plate 13, the control unit increases the current value and raises the support rod 31 to raise the valve body 33 if the cooling is insufficient due to the low rotation speed. is seated on the valve seat 32. As a result, the introduction of the refrigerant gas at the discharge pressure Pd into the crank chamber 5 is stopped. Then, since the force acting on the back surface of the piston 15 becomes smaller, a moment change occurs in the rocking plate 13, and the compressor gradually expands its discharge capacity. Finally, as shown in FIG. 1, the stroke of the piston 15 is shifted to the maximum displacement with a long stroke.

Note that when the crank chamber pressure pc further increases, the spool 40 in the safety valve 23 moves downward from the top dead center, and the refrigerant gas in the crank chamber 5 is actively led out to the suction chamber 17 via the bleed passage 21. Damage to shaft seals, etc. is prevented.

Therefore, in this compressor, even under an engine whose rotational speed is constantly changing, the electromagnetic clutch is not connected or disconnected, and the compressor is operated according to the rotational speed of the drive shaft 6 and the inclination angle of the rocking plate. An indoor environment can be obtained.

At this time, since the sensor 16 receives the magnetic force of the ball 131a of the guide pin 131 that has been magnetized in advance, a special object to be detected is not required.

In addition, in the above embodiment, the ball 13 of the guide pin 131
1a is magnetized and the sensor 16 detects this magnetic force, but it is also possible to magnetize both shoes 10 and 11 and detect the magnetic force with the sensor 16.

Further, in the above embodiment, the control valve 22 is provided with the solenoid 39, and the current value to the solenoid 39 is changed by a signal pulse from the sensor 16.
3 may be provided with a similar solenoid, and the current value to the solenoid may be changed by a signal pulse from the sensor 16.

"Effects of the Invention" As detailed above, in the compressor of the first invention, an axial guide groove is carved in the housing, and a guide pin that slides in the guide groove via a shoe is provided in the rocking plate. Since the shoes and the guide pins are fixed and magnetized to attract each other, the shoes will not fall off the guide pins during the assembly process, and a good assembly can be achieved.

Furthermore, in the compressor of the second invention, since the housing is provided with a detection means for detecting the rotational speed of the drive shaft and the inclination angle of the rocking plate by receiving the magnetic force of the shoe or the guide pin, a good assembly can be achieved. In addition, the controllability of compression capacity control can be satisfied.

[Brief explanation of the drawing]

Figures 1 to 5 relate to a compressor according to an embodiment of the present invention, in which Figure 1 is a longitudinal sectional view at the maximum inclination angle, Figure 2 is a longitudinal sectional view at the minimum inclination angle, and Figure 3 is the main part. Perspective view, Figure 4 is a cross-sectional view of main parts,
FIG. 5 is a schematic diagram showing characteristics of signal pulses. 1... Cylinder 1a... Bore 2... Front housing 5... Crank chamber (Pc... Crank chamber pressure) 6.
... Drive shaft 8 ... Swash plate 10.11 ... Shoe 12 ... Guide groove 13 ... Rocking plate 131 ... Guide pin 131
a...Ball 15...Piston 16...Sensor (detection means) 17...Suction chamber (Ps...Suction pressure) 18...Discharge chamber (Pd...Discharge pressure) Patent applicant Hiroshi Okawa, Patent Attorney, Toyota Automatic Machinery Co., Ltd.

Claims (2)

[Claims] (1) A drive shaft rotatably supported within the housing;
A swash plate that rotates at a predetermined angle of inclination in response to rotation of the drive shaft, a oscillation plate that performs a rocking motion depending on the angle of inclination of the swash plate as the swash plate rotates, and a swash plate provided in the cylinder block. and a piston that is housed in a bore and reciprocates within the bore in response to the rocking motion of the rocking plate, and the reciprocating motion of the piston forms a compression chamber in the bore, and the crank chamber pressure and In a variable capacity oscillating swash plate type compression in which the compression capacity is controlled by changing the inclination angle of the oscillating plate by changing the stroke of the piston according to the differential pressure with respect to the suction pressure, the housing includes: A guide groove is carved in the axial direction, and a guide pin that slides in the guide groove is fixed to the rocking plate via a shoe, and the shoe or the guide pin is magnetized to attract each other. A variable capacity oscillating swash plate compressor characterized by: (2) The variable capacity swing according to claim 1, wherein the housing is provided with a detection means for detecting the magnetic force of the shoe or the guide pin at a position facing the locus of the guide pin. Swash plate compressor.