JPH0220838B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a variable compression capacity compressor, and more specifically to an improvement in a slide vane compressor equipped with a variable compression capacity mechanism.

Prior Art As a method of varying the compression capacity in a conventional slide vane compressor, a bypass hole is provided that communicates the compression chamber and the suction chamber, and a spool for opening and closing the bypass hole is provided in the bypass hole, and the spool is not always in use. The spool is slidably provided so as to be biased in the direction of opening the bypass hole, and on both sides of the spool there is a high pressure chamber communicating with the compression stroke of the compressor, and a suction chamber or a suction chamber connected to the suction stroke of the compression chamber. Low-pressure chambers that communicate with each other are installed facing each other, and a bypass hole is opened and closed via the pressure difference that occurs between the high-pressure chamber and the low-pressure chamber when the compressor is operating, and refrigerant gas that is in the middle of compression is released from the bypass hole to the suction chamber side. method, or a method of varying the effective compression volume in the compression chamber by rotatably providing a plate with a suction hole in the side plate and adjusting the opening area of the suction hole (USP No. 4060343), etc. However, in the above method, due to the small opening area of the bypass hole, the amount of refrigerant gas escaping from the bypass hole cannot keep up with the speed of rotation at high speeds, resulting in a variable effect on the compression capacity. There is a problem in that it causes a problem that it becomes impossible to obtain. In addition, the method requires a rotating mechanism for the plate that opens the suction hole, and since the rotation stroke is large, a motor is required, making the mechanism complicated and large-scale. have

Purpose The present invention is an attempt to improve the conventional situation as described above, and its purpose is to improve the compression capacity variable function.

Structure: The present invention is characterized by its simple structure and by being able to obtain a sufficient capacity reduction effect even during high-speed rotation. A sub-suction hole is continuously formed at the end, the sub-suction hole is along the compression direction of the compressor,
A portion thereof opens into the compression chamber, and the sub-suction hole is provided with an on-off valve having a width narrower than the substantially radial width of the sub-suction hole so as to be able to move forward and backward in the substantially radial direction of the compressor. A high-pressure chamber and a low-pressure chamber are provided facing each other at both ends along the forward and backward direction of the on-off valve, and the high-pressure chamber is communicated with the compression stroke of the compression chamber, while the low-pressure chamber is connected to the high-pressure chamber by opening a sub-intake port. The reason is that it is configured to include a biasing spring.

Note that in the present invention, the substantially radial direction is a direction that intersects with the circumferential direction.

Embodiments Specific embodiments of the present invention will be described below with reference to illustrative drawings.

1 to 5 are drawings showing a first embodiment, and 1 indicates a housing forming the outer shell of the compressor. The housing 1 includes a rear housing 1R formed into a bottomed cylindrical shape with an opening at one end;
It is formed by a front housing 1F that covers the opening of the rear housing 1R. Reference numeral 2 denotes a cylinder block built into the rear housing 1R, and the cylinder block 2 is formed into a central cylindrical shape with openings at both front and rear ends. 3F, 3
R is a pair of front and rear side plates built into the rear housing 1R so as to cover both the front and rear openings of the cylinder block 2, 3F is a front side plate, and 3R is a rear side plate. Reference numeral 4 denotes a drive shaft which is disposed horizontally between both side plates 3F and 3R with its center line offset relative to the cylinder block 2, and a rotor 5 is integrally fixed to the drive shaft 4. The rotor 5 is built into the cylinder block 2 so that a part of its outer peripheral wall can slide against the inner wall surface of the cylinder block 2, and between the outer peripheral wall of the rotor 5 and the inner wall surface of the cylinder block 2. A compression chamber 6 is formed. 7... are vane grooves carved in four places on the rotor 5, and each vane groove 7... is the first groove in the longitudinal direction of the rotor 5, that is, in the axial direction.
As shown in the figure, it is provided so as to extend through both the front and rear end surfaces. Each of the vane grooves 7 has a back pressure chamber 7' at its base, and the vanes 8 are fitted therein so as to be freely extended. A suction chamber 9 is provided between the front housing 1F and the front side plate 3F, and a suction hole that communicates the suction chamber 9 with the compression chamber 6 is opened in the front side plate 3F. The suction hole consists of a main suction hole 10A and a sub suction hole 10B, and the main suction hole 1
0A is provided in correspondence with the suction stroke of the compression chamber 6. That is, it is opened in an arch shape from the starting end of the compression chamber 6 to a position where the volume of the compression chamber 6 is approximately maximum. The sub suction hole 10B is the main suction hole 10B.
Continuing from A, it is provided in a rectangular shape in correspondence with the initial compression stroke. The sub suction hole 10B extends in a direction in which its short side is parallel to the extension line along the radial direction of the rotor 5, and in a direction in which its long side is perpendicular to the extension line along the radial direction of the rotor 5, and a part thereof. is provided so as to face the side wall surface of the cylinder block 2, and the remaining part is provided so as to face the compression chamber 6 along the compression direction.
An on-off valve 18 of the sub-suction hole 10B is provided in the sub-suction hole 10B so as to be movable forward and backward along the short side direction. The on-off valve 18 has a valve body 18A and a valve body 1.
The valve body 18A is composed of a valve rod 18B extending in a direction perpendicular to the sub-intake hole 1.
The valve rod 18B is formed into a long plate shape with a width that is approximately half the width of the short side of the valve rod 18B, and a low pressure chamber 19 is provided at one end of the valve rod 18B on the compressor center side (rotor 5 side).
However, a high pressure chamber 20 is provided at one end of the valve rod 18B on the outer peripheral side of the compressor (on the side of the rear housing 1R) so as to face each other. And from the high pressure chamber 20 there is a pressure guiding hole 21.
is extended, and its tip (pressure detection section 21') is provided so as to face the compression stroke of the compression chamber 6. or,
A pressure guide hole (not shown) extends from the low pressure chamber 19, and its tip (pressure detection section) is provided so as to face the suction chamber 9. A spring 22 is interposed in the low pressure chamber 19, and is provided so as to normally bias the on-off valve 18 toward the high pressure chamber 20 and open the auxiliary suction hole 10B.

On the other hand, at the other end of the compression chamber 6, that is, at a position corresponding to the terminal end along the rotational direction of the rotor 5, a part of the cylinder block 2 is cut out to form a rear housing 1R.
A discharge chamber 11 is formed between the discharge chamber 11 and the inner wall surface of the compression chamber 6, and a discharge hole 12 is provided so as to communicate between the discharge chamber 11 and the terminal end of the compression chamber 6. 13 is the same discharge hole 12
13' is a retainer that regulates the opening angle of the discharge valve 13. 14 is an oil separation chamber formed between the rear wall portion of the rear housing 1R and the rear side plate 3R;
4 is a through hole 15 that opens in the rear side plate 3R.
A filter 16 is provided at the tip of the through hole 15 . Further, an oil reservoir 17 is formed at the lower end of the separation chamber 14.

FIG. 6 is a drawing showing the second embodiment,
31 is a housing, 32 is a cylinder block, and a rotor 33 is rotatably provided in a hollow part formed in an oval shape in the cylinder block 32, and a vane groove formed in the rotor 33 is provided in the rotor 33. A vane 35 is fitted into the vane 34 so as to be freely protrusive. A plurality of compression chambers 38, 38 are formed between the rotor 33 and the inner wall surface of the cylinder block 32 with a displacement angle of 180 degrees.
A main suction hole 36A is provided at the starting end of both compression chambers 38, 38.
and an auxiliary suction hole 36B are provided in succession, and on-off valves 37, 37 are provided in the auxiliary suction holes 36B, 36B so as to be openable and closable. (The structures of the sub-suction hole 36B and the on-off valve 37 are the same as those in the first embodiment, so a detailed explanation will be omitted.) Also, a discharge hole 39 is opened at the end of both compression chambers 38, 38, 40 is provided so as to communicate with it.

Next, its effect will be explained.

In the first embodiment shown in FIGS. 1 to 5, when the compressor is stopped, each part of the compressor, that is, the suction chamber 9, the compression chamber 6, the discharge chamber 11, and the separation chamber 14, is The pressure is in a balanced state.

Also, the pressures in the high pressure chamber 20 and the low pressure chamber 19 are in a balanced state, and the on-off valve 18 is biased toward the high pressure chamber 20 via the spring 22, and the auxiliary suction hole 10
B is in the state of being released. Then, in the state where the sub suction hole 10B is opened as described above, the rotor 5 and the vane 8 are rotated by rotating the drive shaft 4 through the connection operation of the electromagnetic clutch (not shown).
The rotational action of... and the action of sucking the refrigerant gas in the suction chamber 9 into the compression chamber 6 through the suction hole through the rotational action of the rotor 5 and vane 8 are obtained. Since the sub suction hole 10B is in the open state, the vane 8 is connected to the sub suction hole 1.
The compression action starts immediately after passing 0B.
That is, the compression start time can be delayed, and the compression capacity can be reduced accordingly. By obtaining a small-capacity compression action at startup in this way, smooth start-up can be achieved, and an action to prevent liquid compression from occurring can be obtained. By obtaining the above-mentioned compression action, the pressure within the compression chamber 6 is gradually increased and a pressure difference is generated between the compression chamber 6 and the suction chamber 9. 2
When a pressure exceeding the set pressure No. 2 is detected, the on-off valve 18 overcomes the biasing pressure of the spring 22 and is pressed toward the low pressure chamber 19, thereby opening the sub suction hole 10B.
A state is obtained in which the area is occluded. and sub-intake hole 10
When B is blocked, the vane 8 becomes the main suction hole 1.
The effect of starting compression immediately after passing 0A can be obtained. In other words, 100% operating condition can be obtained. By achieving 100% operating conditions in this way, the cooling load in the passenger compartment gradually decreases, but as the cooling return load in the passenger compartment decreases and the suction pressure decreases, the high pressure Chamber 20 (high pressure chamber pressure
P ₁ ) and the low pressure chamber 19 (low pressure chamber pressure P ₂ ) in a state where the differential pressure ΔP=P ₁ −P ₂ falls below the set pressure of the spring 22, the on-off valve 18 returns to the high pressure chamber 20.
The effect of being biased in the direction and opening the sub suction hole 10B is obtained. That is, a small capacity compression effect can be obtained, and the sub-suction hole 10B is formed in a long hole shape along the compression direction of the compression chamber 6, and the valve body 18A is moved back and forth in the width direction of the sub-suction hole 10B. In particular, since the opening/closing valve 18 is provided to be opened/closed, a large capacity reduction effect can be obtained with a small stroke of the opening/closing valve 18.

In addition, a conventional structure in which a bypass hole is provided during the compression stroke of the compression chamber to reduce the compression capacity by releasing a part of the refrigerant gas in the middle of compression to the suction chamber is shown in Fig. 8. When refrigerant gas flows out from the bypass hole, the refrigerant gas in the part immediately after the vane with a low compressed density flows out, and then the refrigerant gas with a high compressed density flows out. When the refrigerant gas with a high compressed density is forced to the opening position of the bypass hole, the refrigerant gas itself already has inertia force to move in the direction of movement of the vanes, so it is impossible to change the direction toward the bypass hole. However, in the present invention, as shown in FIG. 7, the vane As the vane moves forward in the process of passing through the auxiliary suction hole, the compressed density of the refrigerant gas at the front surface of the vane is increased, and the refrigerant gas passes through the auxiliary suction hole and wraps around behind the vane, thereby achieving a smooth refrigerant gas release action. I can do it.

Furthermore, the valve body 18A is formed in a rectangular shape with a flat surface, and is provided so as to be in close contact with the cylinder block 2, thereby effectively preventing leakage of refrigerant gas from the sliding portion of the valve body 18A. It is possible to obtain the effect of preventing i.e. 100%
Compression action can be effectively obtained.

In the above embodiment, the low pressure chamber 19 is provided so as to communicate with the suction chamber 9 through the pressure guiding hole.
The low pressure chamber 19 does not necessarily need to communicate with the suction chamber 9. That is, it is also possible to form the low pressure chamber 19 in the shape of a closed room. And like this, the low pressure chamber 19
By forming the chamber in the shape of a closed chamber, leakage of the refrigerant gas accumulated in the low pressure chamber 19 can be delayed when acting in the direction of closing the on-off valve 18, and the on-off valve can be closed more slowly by that amount. is obtained.

Further, the on-off valve 18 can be provided so as to open only when the compressor is stopped, and it is also possible to respond to changes in the cooling load during operation by controlling the electromagnetic clutch on and off. Sub suction hole 10
B. The on-off valve 18 is not limited to a rectangular shape, and may be curved along the compression chamber. In this case, high processing accuracy is required. Although it is desirable that the main suction hole and the sub suction hole be provided consecutively in order to improve gas flow, they may be separated from each other by a small distance.

The present invention is constructed as described above, and includes:
As described above, the sub-suction hole is continuously formed at the downstream end of the main suction hole, and the sub-suction hole runs along the compression direction of the compressor, and a part of it opens into the compression chamber, and the sub-suction hole is The auxiliary suction hole is opened and closed by moving the on-off valve, which has a width narrower than the approximately radial width of the auxiliary suction hole, in the approximately radial direction of the compressor, so that the on-off valve can be moved back and forth by a small stroke. By doing so, it has become possible to open the initial compression stroke portion of the compression chamber over a wide range, and thereby it has become possible to obtain an effective capacity reduction effect. That is, it has become possible to obtain a sufficiently unloaded state even during high-speed rotation.

In addition, in the present invention, if the on-off valve is formed into a rectangular shape as described above and is configured to move forward and backward while being in close contact with the side plate, the refrigerant gas from the sliding part of the on-off valve can be prevented. Can prevent leakage,
This makes it possible to increase volumetric efficiency during 100% operation.

In other words, the compression effect can be enhanced.

Further, in the present invention, since the structure is simple, a variable capacity mechanism that is easy to manufacture and highly reliable can be obtained at low cost.

[Brief explanation of drawings]

1 to 5 are drawings showing the first embodiment, in which FIG. 1 is a sectional view taken along line AA in FIG. 2, FIG. 2 is a sectional view taken along line BB in FIG. 1, 3 is a sectional view taken along line CC in FIG. 1, FIG. 4 is a sectional view taken along line DD in FIG. 3, and FIG. 5 is a sectional view taken along line EE in FIG. 3. FIG. 6 is a sectional view showing the second embodiment. FIG. 7 is a schematic diagram showing the operating state of the present invention, and FIG. 8 is a schematic diagram showing the operating state of the conventional structure. 1...Housing, 1F...Front housing, 1R...Rear housing, 2...Cylinder block, 3F...Front side plate, 3
R...Rear side plate, 4...Drive shaft, 5...
...Rotor, 6...Compression chamber, 7...Vane groove,
7'... Back pressure chamber, 8... Vane, 9... Suction chamber,
10A...Main suction hole, 10B...Sub-suction hole, 11
...Discharge chamber, 12...Discharge hole, 13...Discharge valve,
13'...Retainer, 14...Separation chamber, 15...
...Through hole, 16...Filter, 17...Reservoir,
18... Open/close valve, 18A... Valve body, 18B...
Valve rod, 19...Low pressure chamber, 20...High pressure chamber, 21...
...Pressure hole, 21'...Pressure detection part, 22...Spring,
31... Housing, 32... Cylinder block, 33... Rotor, 34... Vane groove, 35
... Vane, 36A ... Main suction hole, 36B ... Sub-suction hole, 37 ... Opening/closing valve, 38 ... Compression chamber, 39
...Discharge hole, 40...Discharge chamber.

Claims (1)

[Claims] 1 A sub-suction hole is continuously formed at the downstream end of the main suction hole,
The auxiliary suction hole is along the compression direction of the compressor, and a part thereof opens into the compression chamber, and the auxiliary suction hole is provided with an on-off valve having a width narrower than the approximately radial width of the auxiliary suction hole. A high-pressure chamber and a low-pressure chamber are provided facing each other at both ends along the forward-backward direction of the on-off valve, and the high-pressure chamber communicates with the compression process of the compression chamber, while the low-pressure chamber A variable compression capacity mechanism in a slide vane type compressor, in which a spring is inserted to bias the sub-suction hole toward the high-pressure chamber so as to open the sub-suction hole.