JPH0418152B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotary compressor, particularly a variable displacement rotary compressor useful as a refrigerant compressor for an automobile cooler system.

(Prior art) A rotary compressor for a refrigerant compressor used in an automobile cooler system is a variable capacity rotary compressor that reduces power consumption by changing its capacity in response to the demand for improved fuel efficiency of automobiles. has been devised. For example, as disclosed in Japanese Patent Application Laid-Open No. 58-128487, a plurality of bypass holes (communicating the working chamber and the suction chamber) are provided in the compressor body, and a cylinder hole provided to intersect with the bypass holes is A system has been devised in which the discharge capacity of a rotary compressor is controlled by sequentially opening and closing a group of bypass holes using a slidably provided spool.

(Problems to be Solved by the Invention) Considering various conditions, a rotary compressor is required to have a wide variable range of discharge capacity, to be able to change the capacity continuously, and to be small. . Therefore, the above-mentioned bypass hole group needs to be arranged so as to communicate the suction chamber and the working chamber between the state where the working chamber has the maximum volume and the state where the working chamber has the minimum volume. However, there is a problem in that simply arranging the bypass hole groups in a straight line as in the past cannot satisfy the requirements because the rotor and the like are cylindrical.

Furthermore, according to the inventors' experimental research, in order to reduce power consumption during capacity control, it is necessary to It has been found that communicating with the suction chamber through a large-area bypass hole is effective. However, if the diameter of the bypass hole is made larger than the width (thickness) of the vane, there is a problem that adjacent working chambers separated by the vane will communicate with each other, and the diameter of the bypass hole is limited. It was hot. Therefore, in the high rotation range of the compressor, there is a problem in that the refrigerant is not sufficiently bypassed from the working chamber to the suction chamber, and power consumption is not reduced.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a housing that forms a compressor body with an operating chamber that repeatedly changes volume while operating as the rotor rotates; In the rotary compressor, the rotary compressor has a suction chamber that communicates with the working chamber that has entered a volume increase process via a suction passage, and a discharge chamber that communicates with the working chamber that has reached a discharge pressure via a discharge port. A plurality of first bypass holes are provided in the housing and communicate with the suction chamber and the working chamber, which has entered the stage of volume reduction, and are arranged along a straight line. a second bypass hole that communicates the working chamber and the suction chamber when the working chamber enters the volume reduction stage, and when the working chamber cuts off communication with the suction passage and enters the volume reduction stage; and at least one of the second bypass holes communicates the working chamber and the suction chamber.

(Function) When the working chamber of the rotary compressor is in the early stage of the compression stroke, that is, when the working chamber cuts off communication with the suction passage and enters the stage where the volume decreases, the first bypass hole and the second bypass hole If at least one of them communicates the working chamber with the suction chamber, the working fluid in the working chamber is bypassed to the suction chamber through the bypass hole. Therefore, since the working fluid in the action chamber at the beginning of the compression stroke is bypassed to the suction chamber, the power consumption for compressing the work chamber is reduced, and at the same time, the discharge amount is reduced.

Further, a first bypass hole arranged on a straight line,
By providing the second bypass hole, it becomes possible for the bypass hole to communicate between the working chamber and the suction chamber in the range where the volume of the working chamber is from the maximum to the minimum, and the bypass hole can be sequentially opened and closed to open and close the working chamber. By controlling the amount bypassed from the pump to the suction chamber, the discharge volume can be varied over a wide range and continuously.

(Effects of the Invention) The present invention has a simple configuration in which a first bypass hole and a second bypass hole are provided, but the discharge capacity can be varied over a wide range, and the capacity can be continuously changed. A capacity type rotary compressor can be provided. Furthermore, it has the excellent effect of reducing power consumption during capacity control compared to conventional systems.

(Example) Next, an example of the present invention will be described. FIG. 1 is a longitudinal cross-sectional view of this embodiment, and FIG. 2 is a cross-sectional view taken from FIG. 1. In Figs. 1 and 2, reference numeral 1 denotes a cylindrical housing that forms the outer shape of the compressor, and inside this housing 1 is a cylindrical cylinder 2.
A rotor 3 is arranged inside the cylinder 2 so as to be eccentric from the center of the cylinder 2. A front plate 4 is provided on the front end surface of the cylinder 2 and the rotor 3, and a rear plate 5 is provided on the rear end surface of the cylinder 2 and the rotor 3.
and are fixed to each other by bolts 6 and 7. The rotor 3 is provided with two vane grooves 8a that pass through the center of the rotor and are separated by 90 degrees in the circumferential direction.
The vane 8 is slidably inserted into the vane groove 8a. A working chamber A is defined by the vane 8, the inner wall of the cylinder 2, the front plate 4, and the rear plate 5. Also,
A front shaft 3a is integrally formed on the front end surface of the rotor 3, and a rear shaft 3b is fixed to the rear end surface by bolts 9.
The front shaft 3a is pivotally supported by the front plate 4 via a bearing 10, and the rear shaft 3b is pivotally supported by the rear plate 5 via a bearing 11. A front housing 12 is disposed on the further front side of the front plate 4, and the rotor 3, cylinder 2, and rear plate 5
A rear housing 13 is disposed so as to enclose the rear housing 13. The front housing 12, the front plate 4, and the rear housing 13 are fixed to each other with bolts 14.

Further, a suction chamber B is formed by the front plate and the front housing 12, a discharge chamber C is formed by the rear housing 13 and the cylinder 2, and the rear housing 13 and the rear plate 5 form a discharge chamber C.
An oil separation chamber D is formed by. The oil separator D is provided with an oil separator 16 that separates oil in the discharged refrigerant. Further, the rear housing 13 is provided with a discharge port 50 for discharging the refrigerant discharged to the oil separation chamber D to the condenser of the refrigeration cycle. The housing 2 is provided with a discharge passage 17 for guiding refrigerant from the working chamber A to the discharge chamber C, and the front plate 4 is provided with a suction passage 25 for sucking refrigerant from the suction chamber B. ing.

As shown in FIGS. 2 and 3a, the front plate 4 is provided with a first bypass hole 18a and a second bypass hole 18b to communicate the working chamber A and the suction chamber B, which have entered the stage of volume reduction. are doing. Here, the positions where the first bypass hole 18a and the second bypass hole 18b are provided are determined so that the refrigerant is bypassed in the working chamber A at the beginning of the compression stroke. That is, the first bypass hole 18a is connected to at least one bypass hole when the working chamber A is in the initial stage of the compression stroke, that is, when the communication with the suction passage is cut off and the volume decreases. A second bypass hole 18b is provided. Furthermore, the details will be explained.

As shown in FIGS. 2 and 3a, the front plate 4 has four first bypass holes that communicate between the working chamber A, which has entered the stage of volume reduction (in the compression stroke), and the suction chamber B. 18a are arranged along a straight line, and the front plate 4 is provided with a first spool hole 19a that intersects with the first bypass hole group 18a. Actually, Figure 3b
As shown in , the first bypass 18a is located on the working chamber A side of this front plate 4, and the suction chamber B
There is a long hole 50 on the side, and both are connected to the spool hole 19a.
is passing through. A first spool 20a is slidably provided in the first spool hole 19a. A first control chamber 21a is formed between one end of the first spool hole 19a and the first spool 20a, and this first control chamber 21a is connected to the passage 22.
The high-pressure refrigerant in the discharge chamber C or the working chamber A, which is in the process of decreasing in volume, is introduced via a.

On the other hand, at the other end of this first spool hole 19a,
A spring 24a supported at one end of the cap 23a is disposed and biased in a direction to open the first group of bypass holes 18a of the first spool 20a. By this movement of the first spool 20a, the first bypass hole group 18a is sequentially controlled to open and close.

Similarly, between the suction passage 25 of the front plate 4 and the first bypass hole group 18a, there is a second hole which communicates with the working chamber A, which is in the process of decreasing its volume, and the suction chamber 1B.
A bypass hole 18b is provided.

A second spool hole 19b is provided which intersects with this second bypass hole 18b. A second spool 20b is slidably provided in the second spool hole 19b. A second control chamber 21b into which high-pressure refrigerant is similarly introduced via a passage 22b is formed at one end of the second spool hole 19b, and a cap 23 is formed at the other end.
The spring 2 is supported by a spring 2 which urges the second spool 20b in the direction of opening the second bypass hole 18b.
4b is arranged.

And the first and second control rooms 21a, 2
The first and second spools 20
The positions of the holes a and 20b are controlled, and the opening areas of the first and second bypass holes 18a and 18b are controlled.

Here, at the beginning of the compression stroke in the working chamber A,
At least one of the first bypass holes 18a or the second bypass hole 18b is connected to the working chamber A and the suction chamber B.
At least one of both bypass holes always communicates between the working chamber A and the suction chamber B.

In addition, the first bypass group 18 provided on a straight line
By combining A and the second bypass 18b, it becomes possible for both bypass holes to communicate between the working chamber and the suction chamber in a range where the volume of the working chamber A is from the maximum to the minimum.

Note that the diameter of this bypass hole is all that of vane 8.
It is smaller than the wall thickness of.

FIG. 4 schematically shows the arrangement of the electromagnetic valve 15 and the first and second capacity control spools 18a, 18b mechanisms. High-pressure refrigerant is introduced from the discharge chamber C or the compressor A whose volume is decreasing through the pressure introduction passage 22a to the first and second control chambers 21a and 21b. When the solenoid valve 15 is closed, the interiors of the control chambers 21a and 21b are at high pressure due to the high-pressure refrigerant introduced through the passages 22a and 22b. The first and second spools 20a and 20b come to rest at positions where the pressure in the first and second control chambers 21a and 21b and the springs 24a and 24b are balanced, respectively. If the solenoid valve 15 is maintained in a completely closed state, the pressure in the control chambers 21a and 21b will rise, overcoming the biasing force of the springs 24a and 24b, and the first and second bypass holes 18a and 18b will be
It is completely closed by the first and second spools 20a and 20b. Therefore, the bypass holes 18a and 18b that communicate the working chamber A and the suction chamber B are closed, so that the refrigerant in the working chamber A is not bypassed to the suction chamber B and is completely compressed.
The discharge capacity of the rotary compressor is
It becomes 100%.

On the other hand, when the solenoid valve 15 is open, the working chamber A
Since the high-pressure refrigerant introduced through the pressure introduction passage 22 is released to the low-pressure side suction chamber B through the solenoid valve 15, the first and second control chambers 21a, 21
The pressure inside b decreases, and the first and second spools 20
a, 20b are moved by the urging force of springs 24a, 24b, and the first and second bypass holes 18a, 18b are opened. Therefore, part of the refrigerant in the working chamber A is bypassed to the suction chamber B, and the capacity of the compressor becomes smaller.

Based on the above operation, by repeating ON-OFF of the solenoid valve 15, the pressure in the control chambers 21a, 21b can be arbitrarily controlled, and the positions of the first and second spools 20a, 20b can be continuously controlled. As a result, the discharge amount of the rotary compressor is continuously controlled.

Note that the first spool 20a and the second spool 20
Each spring 24a, 24 applies a biasing force to b.
The set load b is selected as appropriate.
(Here, the area receiving pressure from the control chambers 21a and 21b is the area where the first and second spools 20
It is assumed that a and 20b are the same. ) That is, if the set loads of the springs 24a and 24b are the same, the first and second spools 20a and 20b
At the same time, the first and second bypass holes 18a and 18b are opened. Also, the set load of the spring 24a is changed to the spring 24a.
4b, the first spool 20a opens the first bypass hole 18a before the second bypass hole 18b is opened by the second spool 20b. In the opposite case, the second bypass hole 18b will be opened before the first bypass hole 18a.

Here, in terms of reducing power consumption, the first and second bypass holes 18a and 18b are opened at the same time, or the second bypass hole 18a is
It is preferable that the bypass hole 18a be opened before the bypass hole 18a. For convenience, the operation described below will be described assuming that the set loads of the springs 24a and 24b are the same and that the first and second bypass holes 18a and 18b are opened simultaneously.

Next, the operation of this embodiment having the above configuration will be explained.

When the driving force of a vehicle engine (not shown) is transmitted to the front shaft 3a via the electromagnetic clutch, the front shaft 3a rotates and at the same time the rotor 3 also rotates within the cylinder 2. This rotation changes the volume of the compression chamber A, and at the point where the volume increases, the refrigerant led from the evaporator (not shown) of the refrigerant cycle is passed through the suction port (not shown) provided in the front housing 12 into the suction chamber. B, and into the compression chamber A through the suction passage 25 provided in the front plate 4. As the rotor rotates, the working chamber A is disconnected from the suction passage 25 and its volume decreases, resulting in a compression stroke. Furthermore, when the volume of the working chamber A decreases and the pressure of the working chamber A reaches the discharge pressure, the high-pressure refrigerant is discharged from the discharge passage hole 17 to the discharge chamber C via the discharge valve. Thereafter, the oil flows out into the oil separation chamber D, separates the lubricating oil in the oil separator 16, and is then discharged from the discharge port 50 to the condenser side.

When the compressor starts up, it is necessary to reduce the start-up load so as not to apply a large shock to the engine when the vehicle is running. That is, at startup, the first,
It is necessary to open the second bypass holes 18a and 18b to reduce the discharge capacity of the compressor. In this example, at startup, the first and second spools 20a, 20
Since there is no pressure difference between the front and rear surfaces of the spools 20a and 20b, the spools 20a and 20b are biased by the springs 24a and 24b, and the first and second bypass holes 18a and 18b
is open. Therefore, the compressor of this example does not give a shock to the engine during startup, and does not cause discomfort to the occupants.

When the compressor requires sufficient discharge capacity, the first and second spools 20a and 20b are connected to the bypass hole 1.
8a and 18b must be closed. Therefore, the solenoid valve 15 is closed to guide all the high-pressure refrigerant from the compressor A to the control chambers 21a and 21 pool b, and the pressure of this high-pressure refrigerant overcomes the biasing force of the springs 24a and 24b, and the spools 20a and 20b are Close the second bypass holes 18a and 18b. That is, under normal operating conditions, the compressor is operated at maximum capacity and exhibits sufficient refrigerant capacity.

On the other hand, when the interior of the vehicle is sufficiently cooled and the discharge capacity of the compressor becomes excessive, a signal is sent to the solenoid valve 15 by a temperature sensor installed in the vehicle interior, a pressure sensor installed in the low pressure piping, etc. is controlled to open and close. Then, the high-pressure refrigerant from the compression chamber A is released from the solenoid valve 15 through the branch passage 27 to the suction chamber B, and the pressure in the controls 21a and 21b decreases, causing the first and second spools 20a and 20b to release the springs 224 and 24b. The bypass holes 18a and 18b are moved by the urging force of the bypass holes 18a and 18b.

As a result, the refrigerant in the working chamber A, which has entered the stage of cutting off communication with the suction passage 25 and decreasing its volume, is transferred to both the bypass holes 18a and 18b at the beginning of the compression stroke.
A bypass hole is provided to the suction chamber B through at least one of them. Therefore, the discharge capacity becomes smaller and its power consumption is reduced. Furthermore, if a plurality of both bypass holes 18a and 18b communicate the working chamber A and the suction chamber B at the beginning of the compression stroke, the amount of refrigerant bypassed increases and the power consumption thereof is further reduced. become.

Here, the opening timing and opening area of the first bypass hole 18a and the second bypass hole 18b are determined by the springs 24a and 2.
Set load of 4b, first and second spools 20a, 2
It is determined by components such as the pressure-receiving area of 0b, and at the same time, it can be arbitrarily determined by conditions such as the temperature inside the vehicle interior.

Next, another embodiment will be described based on FIG. 5. In the embodiments described above, the first and second bypass holes were opened and closed by each spool, but in this embodiment, one spool can open and close the first and second bypass holes.
It opens and closes the second bypass hole.

As shown in the schematic view of the main part of FIG. 5, the front plate 4 is provided with a first bypass hole 18'a along a straight line as described above. The first bypass hole group 18'a intersects the first spool hole 19', and the first spool 20' is inserted into the first spool hole 19'. 2nd bypass hole 1
One end of the hole 8'b is connected to the first hole end of the front plate 4.
It is located between the bypass hole group 18'a and the suction passage 25 and opens into the working chamber A. The other open end is opened in the first spool hole 19'a.
Therefore, due to the movement of the first spool 20', the second bypass hole 18'b is connected to the working chamber A through the first spool hole 19'a, similarly to the first bypass hole group 18'a.
and suction chamber B are communicated with each other. Here, the position at which the second bypass hole 18'b opens in the first spool hole 19'a is determined by the opening timing of the first bypass hole 18'a and the opening timing of the second bypass hole 18'b. This should be selected as appropriate. For example, at the same time as the first bypass hole 18'a located at the bottom in the figure, the second bypass hole 18'a
When opening the bypass hole 18'b, open the second bypass hole 18'b at the same position where the first spool hole 19'a intersects the first bypass hole 18'a located at the lowest position in the figure. Open. Further, when the second bypass hole 18'b is opened at the lowest position of the first spool hole 19'a, the second bypass hole 18'b
are opened before the first bypass hole group 18'a.

As described above, the first bypass hole 18a arranged along the straight line and the second bypass hole 1
By providing 8b, it is possible to communicate the working chamber A and the suction chamber B over a wide range between the state where the working chamber A is at its maximum volume and the state where it is at its minimum volume, and it is possible to continuously communicate with the variable range of the variable capacity. It becomes possible to control over a wide range. Furthermore, even in the high rotation range, the refrigerant in the working chamber A is
Since the suction chamber B is sufficiently bypassed through at least one of the holes 18a and 18b, the power consumption thereof is reduced compared to when only the first bypass hole 18a is used.

In the above embodiment, the second bypass holes 18b, 18'-b are located between the first bypass hole group 18a and the suction passage 25 and are provided in the front plate, but the first bypass hole group 18a is It may be provided between the second bypass holes 18b, 18'-b and the suction passage 25. In this case, it is necessary that at least one of the first bypass hole group 18a is arranged at a position where the working chamber A and the suction chamber B communicate with each other at the beginning of the compression stroke of the working chamber A. .
Further, although there was one second bypass hole 18b, 18'-b in the above-described embodiment, it goes without saying that the same effect can be obtained even if a plurality of second bypass holes 18b, 18'-b are provided.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing a rotary compressor of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, Fig. 3a is a sectional view of the main part of the front plate, Fig. 3b 3 is a sectional view taken along the - line in FIG. 3a, FIG. 4 is a partial schematic diagram for explaining the operation, and FIG. 5 is a diagram showing another embodiment. 1, 4, 5...housing, 3...rotor, 8...vane, 18a, 18'-1, 18a'-2, 18'-
3...first bypass hole, 19a, 19a'...first spool hole, 20a...first spool, 18b, 18'
-b...Second bypass hole, 19b...Second spool hole, 20b...Second spool, 25...Suction passage, A
...Working chamber, B...Suction chamber, C...Discharge chamber.

Claims (1)

[Scope of Claims] 1. A housing that forms the compressor body has a working chamber that repeatedly changes volume while operating as the rotor rotates, and a working chamber that has entered a process of increasing volume that communicates through a suction passage. In the rotary compressor, the rotary compressor is formed with a suction chamber that has reached a discharge pressure, and a discharge chamber that communicates with the working chamber that has reached a discharge pressure via a discharge passage, and the working chamber that is provided in the housing and has entered a stage of volume reduction. A plurality of first bypass holes that are arranged in a straight line and communicate with the suction chamber communicate with the working chamber that is provided in the housing and has entered a stage of volume reduction, and the suction chamber. a second bypass hole that connects the working chamber and the suction passage, and when the working chamber cuts off communication with the suction passage and enters a volume reduction stage, at least one of the first bypass hole and the second bypass hole connects the working chamber and the suction passage. A rotary compressor characterized by communicating with a chamber. 2. The first bypass hole is controlled to open and close by a first spool inserted into a first spool hole that intersects with this bypass hole, and the second bypass hole intersects with this second bypass hole. The rotary compressor according to claim 1, wherein opening and closing of the second spool inserted into the second spool hole provided in the rotary compressor is controlled. 3. Opening and closing of the first bypass hole and the second bypass hole are controlled by a first spool inserted into a first spool hole provided to intersect with the first bypass hole. rotary compressor.