JPH05312145A - Variable displacement compressor - Google Patents

Abstract

PURPOSE:To enable capacity control by a simple structure by providing a sliding type switching valve that is driven by a control piston, on one fluid supply route of a cylinder group, and by providing a rotary valve driven in the same way, on the other fluid supply route. CONSTITUTION:A central cylinder block 2 comprises cylinder blocks 2a, 2b in the front side and the rear side respectively, and double-headed pistons 30a... are inserted into each pair of cylinders 12a... and 13a... that are formed on the cylinder blocks 2a, 2b so that the pistons are freely slid and reciprocated. Each piston 30a is reciprocated by the rotational oscillation of a swash plate 27, while a fluid is taken in from the both sides, and is compressed. A sliding type poppet valve 57 is provided on a suction passage 37 in the front side, while a cylindrical rotary valve 41 is provided on a suction port 47a to the rear side, by which a fluid is supplied when a slit-shape suction port 48 is superimposed on the port 47a. The operation of the valves 57, 41 is controlled by a control piston 50 corresponding to the pressure of a control pressure chamber 51.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate type variable capacity compressor suitable for use as, for example, a refrigerant compressor of an automobile air conditioner.

[0002]

2. Description of the Related Art In an air conditioner for an automobile, a refrigerant compressor is simultaneously driven by an internal combustion engine for traveling, the number of revolutions of which greatly fluctuates according to the traveling state. In order to discharge the refrigerant, it is desirable to be able to change the discharge amount of the refrigerant compressor. As one means for achieving this, for example, in the one disclosed in Japanese Utility Model Publication No. 60-3995, a swash plate type compressor provided with a plurality of cylinders has a rotatable ring-shaped control plate. The effective area of the suction port of each cylinder is narrowed all at once, and the suction resistance is increased to narrow the amount of gas sucked, resulting in a reduction in the discharge amount of the compressor.

[0003]

In the conventional swash plate type variable displacement compressor of the type in which the control plate is rotated to partially close the suction port, thereby increasing the suction resistance and decreasing the discharge amount, When the amount is reduced, the suction resistance increases and power loss occurs, which inevitably reduces efficiency. Further, even if the control plate itself has a simple structure, the mechanism for rotating it tends to be complicated, and the mechanism for varying the discharge amount increases the size and complexity of the entire compressor. However, there is a problem that the cost will increase, and further, since the structure is complicated and delicate, there is a possibility that a failure will occur, so there is still a problem in terms of reliability. In view of these problems, the present invention has an object to make the swash plate type compressor a variable displacement type with a simple and robust structure.

[0004]

As a means for solving the above problems, the present invention provides a cylinder block in which a plurality of cylinders are formed at positions corresponding to each other on the front side and the rear side, and the cylinder block. A plurality of double-headed pistons inserted into each pair and reciprocating therein;
A rotary shaft extending in parallel with the cylinder in the cylinder block; a swash plate integrally provided with the rotary shaft and reciprocating the plurality of pistons by rotating with the rotary shaft; Alternatively, a sliding type opening / closing valve provided in a passage for supplying a fluid to be compressed to the plurality of cylinders formed on either side of the rear side cylinder block and interrupting the flow of the fluid passing through the passage. And a rotary valve that adjusts the flow rate of the fluid passing through the passage by changing the time for opening the passage for supplying the fluid to be compressed to the plurality of cylinders formed on the other side, and the opening / closing valve. And a control piston for driving and controlling the rotary valve, and a control cylinder into which the control piston is inserted and which is supplied with a control fluid pressure. To provide a variable displacement compressor, wherein the door.

[0005]

When the rotary shaft is driven to rotate and the swash plate swings, a plurality of double-headed pistons reciprocate in the pair of cylinders as the swash plate swings. In the passage for supplying the fluid to be compressed to one side of the group or the rear side cylinder group, a sliding type opening / closing valve driven by a control piston inserted in the control cylinder is provided. By operating the sliding type open / close valve according to the control fluid pressure of the control cylinder, the fluid is supplied to or cut off from the cylinder on that side, and the discharge amount is increased or decreased by that amount. .. The passage for supplying the fluid to be compressed to the cylinder group on the other side is provided with a rotary valve which is driven by a control piston similarly to the sliding type opening / closing valve, and the time for opening the passage is changed. Since the flow rate of the fluid passing through the passage is adjusted, the discharge amount in the cylinder group on the other side gradually changes. Therefore, the discharge amount of the compressor as a whole gradually changes due to the cylinder group on the other side, and it is possible to focus on the normally required change range of the discharge amount.

[0006]

FIG. 1 shows a swash plate type compressor as a first embodiment of the present invention. The section taken along line II-II is shown in FIG. Each of the illustrated examples shows a case where the present invention is applied to a refrigerant compressor in an automobile air conditioner. The main body of the swash plate type compressor 1 shown in FIG. 1 is a central cylinder block 2, a front housing 4 fastened with a valve plate 3 on the left side, and a valve plate 5 fastened on the right side with a valve plate 3. And a rear housing 6. The cylinder block 2 is further divided into two parts, a front side cylinder block 2a and a rear side cylinder block 2b. In the illustrated example, five through bolts 7 are used as means for integrally fastening the cylinder blocks 2a and 2b, the valve plates 3 and 5, the front housing 4 and the rear housing 6.

The front cylinder block 2a includes
Five cylinders 12a-1 at even positions around the center
2e (only 12a is shown in FIG. 1) are drilled, and the corresponding cylinder block 2b on the rear side also has 5
Individual cylinders 13a to 13e are provided (see FIG. 2). An annular discharge chamber 14 is formed in the outer peripheral portion of the front housing 4. Further, although the shape and structure are slightly different from the front side, an annular discharge chamber 15 is also formed in the outer peripheral portion of the rear housing 6.

The front valve plate 3 is provided with discharge ports 18a to 18e (only 18a is shown in FIG. 1) capable of communicating the cylinders 12a to 12e with the discharge chamber 14, respectively. It is closed by a discharge valve consisting of a thin spring plate. In addition, 19 is a discharge port 18a
18e illustrates one of the valve retainers for the discharge valves. Similarly, the discharge ports 21a to 21e are opened in the valve plate 5 on the rear side, and the cylinders 13a to 13e can be connected to the common discharge chamber 15 in an annular shape. Then, the discharge chamber 15 on the rear side merges with the pipe from the discharge chamber 14 on the front side through a pipe to communicate with a condenser of a refrigeration cycle (not shown). Similar to the front side, each of the discharge ports 21a to 21e is provided with a discharge valve made of a thin spring plate (not shown). In addition, 22 has illustrated one of the valve retainers.

A swash plate chamber 2 formed in the cylinder block 2
3, a rotary shaft 24 extends from the side surface and is rotationally driven by an internal combustion engine of a vehicle (not shown) via a transmission device such as an electromagnetic clutch. The rotary shaft 24 is supported by radial bearings 25 and 26 provided in the cylinder block 2 in the front and rear thereof. In the swash plate chamber 23, an elliptical swash plate 27 is attached to and integrated with the rotary shaft 24 by a suitable means.
The axial load as a reaction force acting on the bearing 4 is supported by the pair of thrust bearings 28 and 29.

Each pair of cylinders 12a-12e and cylinders 13a-13e bored in the cylinder block 2 in parallel with the rotary shaft 24 has a double-headed piston 3 in each pair.
0a to 30e (only one piston 30a is illustrated in FIG. 1) are axially reciprocally slidably inserted, and the grooves at the central portions of the piston rods have, for example, spherical recesses. 31 is formed, and a pair of wear resistant shoes 32 forming a part of a sphere having the same diameter as that of the swash plate 27 are slidably sandwiched between the shoes 32. There is. The swash plate chamber 23 is used as a part of the suction passage of the swash plate type compressor 1, and receives low-temperature low-pressure refrigerant returning from the evaporator provided in the refrigeration circuit of the air conditioner by a suction pipe (not shown). It has become.

A valve cylinder 33 coaxial with the rotary shaft 24 is bored in the center of the front cylinder block 2a, and a slight gap is left in the valve cylinder 33 to form a rotary shaft 24 therein.
The enlarged diameter portion 34 formed in is fitted in such a manner that it can slide and rotate. On the wall surface of the valve cylinder 33, there are suction ports 35a through which communicate with the front side cylinders 12a through 12e, respectively.
35e (only 35a is shown in FIG. 1) is opened, and the enlarged diameter portion 34 of the rotary shaft 24 is provided so as to be able to communicate with them sequentially.
Is formed with a fan-shaped opening 36 in the circumferential direction, which opens at about 130 ° with respect to the axial center.
Is a suction passage 37 on the front side that passes through the axis of the rotary shaft 24.
Is in communication with. Further, a radial suction passage 38 is formed so as to penetrate through both the boss portion of the swash plate 27 and a part of the rotary shaft 24 integrated with the boss portion, and the suction passage 37 on the front side is formed of the passage 38. At least the vicinity of the middle is open to the wall surface which is a flat surface. A part of the suction passage 38 in the radial direction may be a groove formed on the side surface of the boss portion of the swash plate 27, which is the case as shown in FIG. 1.

As shown in FIG. 1, the right end of the rotary shaft 24 has a hollow cylindrical shape, and the internal space thereof is the suction pressure chamber 3.
9 is composed. Also, the cylinder block 2b on the rear side
A valve cylinder 40 on the rear side is formed in the center of the rear side so as to surround the right end of the rotary shaft 24 leaving an annular space. A cylindrical rotary valve 41 on the rear side, as conceptually enlarged and shown in FIG. 3, is inserted into the annular space from the right side, and a slight gap is formed between the rotary valve 41 and the inner wall surface of the valve cylinder 40. The rotary shaft 24 is fitted and supported on the right end of the rotary shaft 24 so as to be slidably rotatable and axially slidable with respect to the rotary shaft 24.

The rotary valve 4 on the rear side is mounted on the rotary shaft 24.
In order to support 1 so as to be slidable in the axial direction while interlocking with the rotational direction, a slit 42 (2 in the example shown in FIGS. 1 and 2 is formed in the axial direction in the cylindrical portion at the right end of the rotary shaft 24. Is formed, and a substantially circular stopper 44 integrally provided with two guide pins 43 protruding outward in the radial direction through the slit 42 is slidable in the axial direction. It is inserted into the hollow portion (suction pressure chamber 39) at the tip of the rotary shaft 24, and the tip of the guide pin 43 is at the end of the rotary valve 41.
Is engaged with the notch 45 in the axial direction. It should be noted that the stopper 44 has, for example, a through hole 46 so as not to prevent the passage of the refrigerant.
It is advisable to provide an appropriate number.

Inlet ports 47a to 47e are opened from the cylinders 13a to 13e formed in the rear cylinder block 2b toward the common valve cylinder 40, and the rotary valve 41 is located at the leftmost side in FIG. When it moves to, the suction ports 47a to 47e of all the cylinders 13a to 13e are closed by the wall surface of the rotary valve 41, and the communication with the suction pressure chamber 39 is cut off.

When the rotary valve 41 moves to the right in the axial direction, the slit-shaped opening provided in the rotary valve 41 as shown in FIG. 3, that is, the width on the circumference is θ ₁ and θ _{2 at} the arc angle. The slit-shaped suction port 48 including two parts, the large size and the small size, and the suction ports 47a to 47e on the rear side overlap. As a result, the refrigerant is sucked into the cylinders 13a to 13e from the suction pressure chamber 39, and the suction amount of the refrigerant is the slit-shaped suction port 48 and the suction ports 47a to 47e.
It will be the size according to the time that each of them overlaps. Therefore, while each of the suction ports 47a to 47e overlaps a portion of the slit-shaped suction port 48 having a large circular arc angle θ ₁ , it has a longer period than a period of overlapping with a portion having a small circular arc angle θ _2. Since the refrigerant is sucked in over, the amount of discharge also increases accordingly. In this way, the amount of the refrigerant sucked into the rear cylinders 13a to 13e, compressed, and discharged is determined by the axial position of the rear rotary valve 41. If the edge shape of the slit-shaped suction port 48 is formed obliquely with respect to the circumferential direction, suction is performed in the rear side cylinders 13a to 13e.
The amount of refrigerant discharged shows a continuous change.

In the embodiment of the rear rotary valve 41 shown in FIG. 3, a large arc angle θ of the slit-shaped suction port 48 is provided.
_Since the start points (intake start timing when viewed from the side of the cylinders 13a to 13e) of the portion _{1 and} the portion of the small arc angle θ ₂ are aligned at the same position, when the air conditioning system is required to have a large air conditioning capacity, The rear side rotary valve 41 is moved to an axial position such that the ports 47a to 47e overlap the portion of the slit-shaped suction port 48 having a large arc angle θ ₁ .
On the contrary, when the cooling capacity becomes excessive, the rotary valve 41 is moved to the axial position overlapping the portion of the small arc angle θ _2.
Will be controlled to move.

By moving the rotary valve 41 on the rear side in the axial direction and cutting a part of the effective stroke of the cylinders 13a to 13e on the rear side stepwise or continuously, the diagram shown in FIG. 4 is obtained. As shown, the piston is sucked over the entire area from the top dead center to the bottom dead center, and the axial position is overlapped with the small arc angle θ ₂ of the slit-shaped suction port 48, for example. Rotary valve 41
If the cylinder is moved, inhalation will be completed in a relatively short period, so the cylinder 13 can be operated from θ ₂ to (2π−θ ₂ ).
The a to 13e will be expanded and compressed while being sealed, and the power consumption required in that case will be substantially zero. Therefore, it is possible to provide a mechanism for varying the discharge amount that has no power loss due to the change in the discharge amount.

A control piston 50 is slidably inserted into a control cylinder 49 formed in the rear housing 6 in the axial direction in order to adjust the movement of the rear rotary valve 41 in the axial direction. The pressure chamber 51 is partitioned. A pressure that varies between the discharge pressure and the suction pressure is supplied to the control pressure chamber 51 by a control valve 52 whose outer shape is shown in FIG.
The force due to the pressure difference between the suction pressure and the suction pressure of the control spring 50, which is loaded between the stopper 44 and the rotary shaft 24 and indirectly biases the control piston 50 to the right in FIG. By changing the balance state with the compression spring 54 that is loaded in the device 51 and biases the control piston 50 to the left, the axial positions of the control piston 50 and the rotary valve 41 on the rear side are controlled, and the slit shape is controlled. By changing the opening period of the suction ports 47a to 47e with respect to the suction port 48, the amount of refrigerant sucked into each of the rear side cylinders 13a to 13e is changed over a wide range (multistep or stepless).

The control operation for changing the discharge amount in this way is as follows.
For example, it may be automatically performed according to the pressure of the refrigerant returning from the evaporator in the refrigeration circuit of the air conditioner to the swash plate chamber 23 of the compressor 1. However, it may be freely performed depending on the intention of the driver. It goes without saying that it is better to be controllable. In FIG. 1, reference numeral 55 denotes a thrust bearing for preventing the control piston 50 from rotating even when the rear rotary valve 41 rotates, and 56 denotes an O-ring for sealing.

In this way, the rear side cylinders 13a-1a
Unlike the amount of refrigerant sucked into 3e, and hence the amount of discharge, is changed stepwise or continuously over a wide range by the action of the rotary valve 41 on the rear side, the suction of the refrigerant to the front side cylinders 12a to 12e. As described above, the poppet valve 57 opens and closes the opening of the suction passage 37 provided in the center of the expanded diameter portion 34 of the rotary shaft 24 to the radial suction passage 38 formed in the swash plate 27 as described above. According to this, either the total supply or the supply cutoff is selected.

The poppet valve 57 is guided movably in the axial direction by inserting and supporting the stem 58 of the poppet valve 57 into the through hole of the stopper 44, and is always biased in the valve closing direction by a relatively weak compression spring 59. .. FIG. 1 shows the front cylinder 12a with the poppet valve 57 closed.
To 12e, the amount of refrigerant sucked into the refrigerant is zero, the rear rotary valve 41 is at the leftmost position, and the suction port 4
7a to 47e are also closed, and the rear cylinder 13
The state in which the amount of refrigerant sucked into a to 13e is also zero, and therefore the amount of discharge of the compressor 1 is zero, is shown.

A small stopper 60 like a nut is formed at the tip of the stem 58 of the poppet valve 57, and the control piston 50 moves axially when the control pressure in the control pressure chamber 51 changes. Then, a part of the slit-shaped suction port 48 formed in the rear rotary valve 41 overlaps with the suction ports 47a to 47e, so that the suction of the refrigerant into the rear cylinders 13a to 13e starts, and the control piston is still maintained. 50 and the rotary valve 41 move to the right, the suction amount and the discharge amount on the rear side gradually increase, and the opening angles of the suction ports 47a to 47e become θ of the suction port 48.
_After shifting from ₁ to θ ₂ and maximizing the discharge amount on the rear side, the stopper 60 contacts the stopper 44.

By engaging the stopper 60 and the stopper 44, the poppet valve 57 is moved to the right following the control piston 50, so that the front suction passage 37 communicates with the radial suction passage 38 and the front suction passage 38 is communicated with the front suction passage 38. Supply of the refrigerant to the side cylinders 12a to 12e starts. Therefore,
Here, although the discharge amount of the compressor 1 suddenly increases, it is ideal that the flow rate of the refrigerant required by the refrigeration circuit of the air conditioner is continuously changed from 0 to the maximum value 1, In practice, an intermediate flow rate of 1 to 1/2 is rarely required, and in practice, the maximum discharge amount during cooldown is 1
When the target temperature is reached, if the discharge amount for maintaining the temperature can be changed from 1/2 to 0, sufficiently fine room temperature control can be performed. Therefore, the discharge amount on the front side can be controlled. It is a good idea to simplify the configuration of the entire device by simplifying the above, which can also increase the overall efficiency of the compressor. The poppet valve 57 is simply used for opening / closing control.

In the first embodiment shown in FIGS. 1 to 3, the discharge amount is controlled to decrease when the pressure in the control pressure chamber 51 becomes higher than the pressure in the suction pressure chamber 39. The discharge amount may be increased under the same conditions. This is, for example, a rotary valve 4 as shown in FIG.
In the case of using No. 1, it can be carried out very easily by changing the axial positions of the portion having the large arc angle θ _{1 and} the portion having the small arc angle θ ₂ in the slit-shaped suction port 48.

A second embodiment of the present invention is shown in FIGS. Only the differences in structure from the first embodiment shown in FIG. 1 will be described. The other points may be considered to be substantially the same as the case of the first embodiment. First, in the first embodiment, the rotary shaft 24 is provided with the enlarged diameter portion 34, and the fan-shaped opening 36 is formed in that portion, so that the refrigerant is supplied to the front side cylinders 12a to 12e in relation to the suction ports 35a to 35e. Although a rotary valve for distributing and supplying sequentially is constructed, in the second embodiment shown in FIG. 5, a cylindrical member 6 is used instead of the expanded diameter portion 34.
2 is manufactured as a member separate from the rotary shaft 24 and fitted,
It is integrated with the rotary shaft 24 by means such as a metal fitting 63. For example, the cylindrical member 62 has a circular arc angle of, for example, 1
Since the slit 61 in the circumferential direction of about 30 ° is provided, the manufacturing of the rotary shaft 24 becomes easy, which is also useful for cost reduction.

In the case of the compressor 1a of the second embodiment, the suction passage 37 shown in FIG. 1 corresponds to the suction passage 64 shown in FIG. 5, and its inner end is formed long in the center of the rotary shaft 24. Is opened in the axial suction passage 65 composed of a hollow portion, and the opening is opened and closed by the head of a slide valve 66 inserted so as to be slidable in the suction passage 65 in the axial direction. It has become so. The head of the slide valve 66 is deeply dented, and the suction passage 65
A compression spring 67 is mounted between the left end and the bottom of
Thereby, the slide valve 66 is urged to the right.
A small piston 66a is formed at the right end of the slide valve 66, and correspondingly, it is slidably fitted into a cylinder 68a formed in a control piston 68. The inside of the cylinder 68a communicates with the control pressure chamber 51, and the control pressure acts on the piston 66a.

When the pressure in the control pressure chamber 51 is high, the control piston 68 is pushed to the left and moves as described later, but before or after that (depending on the strength of the compression spring 67). The slide valve 66 is also pushed to the left to move in the cylinder 68a, compresses the spring 67 and assumes the axial position as shown in FIG. 5, so that the suction passage 64 is opened. As a result, the rotary shaft 24 communicating with the swash plate chamber 23 by the radial suction passage 38 formed in the swash plate 27.
The inner suction passage 65 includes a suction passage 64 and a slit 61,
The refrigerant can be supplied to the front side cylinders 12a to 12e through the suction ports 35a to 35e.

When the pressure in the control pressure chamber 51 begins to drop, the slide valve 66 is pushed by the compression spring 67 before and after the control piston 68 is pushed by the compression spring 72 and moves to the right. Cylinder 64 on the front side is closed
The effective compression action of 2a to 12e is stopped, and the compressor 1
The discharge amount of a is reduced to half. Control piston 68
When the return (movement to the right) of the piston 66a is set after the return of the piston 66a (the spring constant of the compression spring 67 is made relatively large), first the discharge amount on the front side becomes zero. The discharge amount of the compressor 1a is 1/2
After that, the discharge amount on the rear side also gradually decreases.

In the second embodiment shown in FIG. 5, what corresponds to the control piston 50 and the rear rotary valve 41 in the first embodiment is the control piston 68 as a single member. In that sense, in order to move the control piston 68, which also serves as a rotary valve, in the axial direction relatively while giving the same rotation as the rotary shaft 24, an axial slit provided in the cylindrical portion at the tip of the rotary shaft 24. 69 (there are four rows in this embodiment), four guide pins 71 extending outward from an annular stopper 70 as shown in detail in FIG. 6 are engaged and guided in the axial direction. The guide pin 71 engages with the notch 45 formed at the left end of the rotary valve / control piston 68 to transmit the rotation of the rotary shaft 24 to the control piston 68. A compression spring 72 is mounted on the left side surface of the stopper 70 between the stopper 70 and a step portion formed in the axial suction passage 65 in the rotary shaft 24, and like the compression spring 53 in the first embodiment, a rotary spring is used. The valve / control piston 68 is pressed to the right. The slit-shaped suction port 48 provided on the outer peripheral surface of the rotary valve / control piston 68 is similar to that of the first embodiment, and the notch 24a provided at the right end of the rotary shaft 24 is provided in the suction pressure chamber 39. It is designed to communicate. The suction port 48 is used as the control pressure chamber 5.
Depending on the axial position of the rotary valve / control piston 68, which is determined by the pressure of No. 1, the rear cylinders 13a ...
This serves to change the amount of the refrigerant supplied to 13e over a wide range.

As is apparent from the above description, the control pressure of the control pressure chamber 51 in the second embodiment is different due to the difference in configuration between the compressor 1a of the second embodiment and the compressor 1 of the first embodiment. The discharge amount of the compressor 1a increases when the pressure rises, and the result obtained for the same operation of the control valve 52 is the opposite of that of the first embodiment, but the discharge amount is simplified by the robust mechanism. The effect of being able to change to is the same.

FIG. 7 shows a compressor 1b as a third embodiment of the present invention. First, the first embodiment shown in FIG. 1 and FIG.
Only the points that are different from the second embodiment shown in FIG.
The greatest feature of the third embodiment is that the poppet valve 57 or slide valve 66 that opens and closes the refrigerant supply path to the front side cylinders 12a to 12e and the refrigerant supply amount to the rear side cylinders 13a to 13e in the above-described example. For adjusting the rotary valve 41 or the rotary valve / control piston 68
Are integrated into a rotary slide valve 73 as a single member. Another feature is that it penetrates through the rear housing 6 and the suction port 7 is located rearward.
4 is to have.

An axial suction passage 65 is formed inside the rotary shaft 24, which is mostly hollow. A partition wall 75 is provided to divide the suction passage 65 into two parts, and an opening formed in the partition wall 75. The front end of the rotary slide valve 73, which is itself hollow and has an internal space communicating with the suction port 74, is inserted into the opening window 7 provided on the side surface of the end.
6 is opened and closed depending on the engagement positional relationship with the partition wall 75, and the refrigerant supply to each of the front side cylinders 12a to 12e is interrupted. A spline 77 is formed on the outer periphery of the intermediate portion of the rotary slide valve 73. The spline 77 engages with a spline formed on the hollow inner surface at the right end of the rotary shaft 24, thereby rotating the rotary shaft 24 relative to the rotary shaft 24. The slide valve 73 is movable in the axial direction while rotating the same. The compression spring 78 that biases the rotary slide valve 73 axially to the right is a partition wall 75.
It is loaded between and.

In the third embodiment, since the suction port 74 is formed so as to penetrate the center position of the rear housing 6, the annular control piston 79 is provided. The control piston 79 is fitted on the outer peripheral surface of the cylinder 80 protruding into the rear housing 6 so as to form the suction port 74, and contacts the right end surface of the rotary slide valve 73 under the bias of the compression spring 78. It is possible to slide integrally in the axial direction. Therefore, the control pressure chamber in the third embodiment is 81
However, the actions of the control pressure chamber 81 and the control piston 79 are essentially the same as those corresponding to those of the first and second embodiments. The slit-shaped suction port 48 formed in the rotary slide valve 73 is also the same as that described above. Note that reference numerals 82 and 83 in FIG. 7 denote O-rings for sealing the control piston 79.

In the compressor 1b of the third embodiment, the return refrigerant is supplied from the suction port 74 provided at the center of the rear housing 6, and the control piston 79 and the rotary slide which are determined according to the control pressure of the control pressure chamber 81. Depending on the axial position of the valve 73, the opening window 76 is opened and closed to supply or stop the refrigerant to the front side cylinders 12a to 12e. Thereby, the discharge amount of the compressor 1b is switched to one half or one half. For example, when the opening window 76 is closed, the slit-shaped suction port 48 is provided.
And the degree of overlap with the suction ports 47a to 47e changes due to the axial movement of the rotary slide valve 73, the refrigerant supply amount to the rear side cylinders 13a to 13e changes,
It is possible to realize a change in the discharge amount from 1/2 to 0.

[0035]

According to the present invention, a simple mechanism for making a swash plate type compressor a variable capacity can be compactly incorporated into the compressor, so that the entire compressor including the variable capacity mechanism can be used. Although miniaturized, it provides the necessary and sufficient variable capacitance function. Further, since the structure of the variable capacity mechanism itself is robust and the operation is reliable, the reliability can be improved as compared with the prior art.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing a first embodiment of a swash plate type compressor according to the present invention.

FIG. 2 is a cross-sectional side view taken along the line II-II in FIG.

FIG. 3 is a perspective view conceptually showing an enlargement of a rear rotary valve.

FIG. 4 is a diagram for explaining the operation.

FIG. 5 is a vertical sectional front view showing a second embodiment of the swash plate compressor according to the present invention.

FIG. 6 is a detailed view of a stopper used in the second embodiment, (1) is a front view and (2) is a side view.

FIG. 7 is a vertical sectional front view showing a third embodiment of the swash plate compressor according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Swash plate type compressor (1st Example) 2 ... Cylinder block 4 ... Front housing 6 ... Rear housing 7 ... Through bolt 15 ... Rear discharge chamber 18 ... Front discharge port 21 ... Rear discharge port 23 ... Swash plate chamber 24 ... Rotating shaft 27 ... Swash plate 30a to 30e ... Double-headed piston 33 ... Valve cylinder 34 ... Rotating shaft expanded portion 35 ... Front side suction port 36 ... Fan-shaped opening 37 ... Front side suction passage 38 ... Radial suction passage 39 ... Suction pressure chamber 40 ... Valve cylinder 41 ... Rear rotary valve 42 ... Slit 43 ... Guide pin 44 ... Stopper 45 ... Notch 47 ... Rear suction port 48 ... Slit suction Port 49 ... Control cylinder 50 ... Control piston 51 ... Control pressure chamber 52 ... Control valve 53, 54 ... Compression spring 57 ... Poppet valve 59 ... Compression spring 60 ... stopper 61 ... slit 62 ... cylindrical member 64 ... suction passage 65 ... axial suction passage 66 ... slide valve 66a ... piston 67 ... compression spring 68 ... rotary valve and control piston 69 ... slit 70 ... stopper 71 ... guide pin 72 ... compression spring 73 ... rotary slide valve 74 ... suction port 75 ... partition wall 76 ... opening window 77 ... spline 78 ... compression spring 79 ... control piston 80 ... cylinder 81 ... control pressure chamber

Claims (1)

[Claims] 1. A cylinder block in which a plurality of cylinders are respectively formed at positions corresponding to each other on a front side and a rear side, and a plurality of double-heads which are inserted into each pair of the cylinders and reciprocate therein. A piston, a rotating shaft extending in parallel with the cylinder in the cylinder block, and a swash plate integrally provided on the rotating shaft for rotating the plurality of pistons by rotating together with the rotating shaft. , A sliding type which is provided in a passage for supplying fluid to be compressed to the plurality of cylinders formed on either side of the front side or rear side cylinder block and which interrupts the flow of the fluid passing through the passage. Of the on-off valve and the passage through the passage for changing the time for opening the passage for supplying the fluid to be compressed to the plurality of cylinders formed on the other side. A rotary valve for adjusting a body flow rate, a control piston for driving and controlling the on-off valve and the rotary valve, and a control cylinder into which the control piston is inserted and which is supplied with a control fluid pressure. Variable capacity compressor characterized by.