JPH0335513B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a refrigerant compressor having a variable capacity function, and is suitable for use, for example, in air conditioning of bus vehicles.

[Prior Art] In recent years, the annual engine efficiency (cooling capacity/energy used) of compressors used for vehicle air conditioning has been required to improve, and for this reason, the capacity of the compressor has been adjusted according to the required refrigerant capacity. It is proposed to be variable.

For example, Utility Model Application Publication No. 56-115590 discloses a technique for varying the capacity of a compressor by controlling the flow of refrigerant supplied to a predetermined portion of a plurality of cylinders. has been done. However, in this conventional system, since the flow of refrigerant supplied to multiple cylinders is controlled by a single valve, there are significant restrictions on the placement position of the refrigerant flow control valve, and as a result, the overall compressor It had a structure that forced it to be larger. That is, the control valve is arranged in series with the piston in the axial direction of the shaft, resulting in a problem that the size of the compressor increases along the shaft axial direction.

This has been a big problem in practice, especially when the compressor is used for air conditioning with bus vehicles. That is, since the mounting space in a vehicle is extremely limited, it is often difficult to practically adopt a compressor with a large size.

[Problem to be solved by the invention]

The present invention was devised in view of the above points,
In a compressor where multiple cylinders are formed radially around the cylinder in the housing, the throttle valve that controls the flow of refrigerant to a predetermined part of the multiple cylinders can be stored in the most compact way. The purpose is to provide a compressor that

That is, the present invention skillfully utilizes the fact that the cylinders are formed radially within the housing, and places the throttle valve, which conducts and cuts off the flow of suction refrigerant, in a portion of the housing between the cylinders that are arranged radially apart. An object of the present invention is to prevent a large space for installing the throttle valve from being required in the shaft axial direction by arranging the throttle valve.

[Means to solve the problem]

In order to solve the above problems, the present invention forms a plurality of cylinders radially within the housing with the shaft as the center, and also has a sub-suction chamber within the housing that supplies refrigerant to each cylinder, and a sub-suction chamber that supplies refrigerant to each sub-suction chamber. A suction chamber is formed in communication with the suction chamber. Similarly, a sub-discharge chamber into which compressed refrigerant is discharged from the cylinder and a discharge chamber which communicates with each sub-discharge chamber so that the refrigerant can collect are formed in the housing. In the present invention, a throttle valve that conducts and interrupts the flow of suction refrigerant is disposed in a portion between the cylinders within the housing thus formed.

Further, in the present invention, a pressure chamber is formed on the back surface of the throttle valve, and a high pressure introduction passage that communicates the pressure chamber with the sub-discharge chamber and a low pressure introduction passage that communicates the pressure chamber and the suction chamber are provided. Furthermore, the throttle valve is provided with a plunger that controls the pressure in the pressure chamber between high pressure and low pressure based on an electric signal.

By arranging the throttle valve in such a positional relationship, the throttle valve can be placed in a position that extends from the suction chamber through the sub-suction chamber and into the cylinder, and in a position that communicates with a predetermined part of the cylinders. It becomes possible.

〔Effect of the invention〕

By employing the above configuration, the size of the entire compressor is significantly increased despite the use of a throttle valve in the present invention. That is, since the area between the radially formed cylinders is originally supposed to be a dead space, arranging the throttle valve in this area does not significantly improve the size of the compressor.

Moreover, in the present invention, since the throttle valve is arranged between the cylinders in the housing, the distances between the throttle valve and the suction chamber and sub-suction chamber communicating with each cylinder are adjacent, and a special refrigerant passage is required. The flow of suction refrigerant supplied to the cylinders can be shut off without making any significant changes in the flow of refrigerant due to its handling.

In addition, by locating the throttle valve between the cylinders within the housing, the distance between the pressure chamber of the throttle valve and the auxiliary discharge chamber and suction chamber can be set short, and the high pressure introduction passage and Routing of the low pressure introduction passage becomes easy.

An embodiment of the compressor of the present invention will be described below based on the drawings.

1 in Figure 1 is a housing, and this housing 1
As shown in FIG. 2, three sets of two cylinders 2a, 2b, 3a, 3b, 4a, 4b are formed in the cylinder. This housing 1 is provided with a bracket 5, and is bolted to a suspension base under the floor of a bus vehicle via the bracket 5. A shaft 6 is rotatably supported by the housing 1 through bearings 7 and 8, and is configured to receive the driving force of the vehicle engine through an electromagnetic clutch and a V-belt (not shown). Incidentally, the electromagnetic clutch is used to interrupt the transmission of power. However, since compressors for bus air conditioning have a large load on the compressor, it is undesirable to start transmitting power while the engine is rotating. 3
Reference numeral 9 denotes a shaft sealing device that prevents the refrigerant in the housing 1 from leaking along the shaft 6.

Reference numeral 9 denotes a drive member whose one end is rotatably connected to the crank portion 6a of the shaft 6, and is used to exchange rotational motion of the shaft 6 with reciprocating motion. and,
A piston 10 is connected to the other end of the drive member 9 via a piston pin 11. Therefore, the piston 10 receives the driving force of the driving member 9 and reciprocates within the cylinders 2a, 2b, 3a, 3b, 4a, and 4b. 12, 13, 14 are cylinders 2 of each set
a, 2b, 3a, 3b, 4a, 4b, with a valve plate 17 in between.
14 is formed with a suction passage chamber 15 that guides the refrigerant into the cylinder, and a discharge passage chamber 16 that passes the refrigerant discharged from the cylinder. A suction hole 18 and a discharge hole 19 are formed in the valve plate 17.
Further, a suction valve 20 and a discharge valve 21 for opening and closing the suction hole 18 and the discharge hole 19 are fixed to the valve plate 17 together with a discharge valve stopper 21a.

As shown in FIG. 4, the housing 1 includes sub-discharge chambers 22, 23, 24 communicating with each discharge passage chamber 16.
Three chambers are formed, and each of these sub-discharge chambers 22, 2
3 and 24 are discharge communication holes 2 of the side plate 25
6, 27, and 28 (shown in FIG. 5), it communicates with the discharge chamber 30 of the rear housing 29. That is,
The three sub-discharge chambers 22, 23, and 24 communicate with each other through a discharge chamber 30 of the rear housing 29. A discharge connection port 31 communicates with the discharge chamber 30, and the refrigerant discharged into the discharge chamber 30 is discharged from the discharge connection port 31 to a condenser (not shown).

Further, sub-suction chambers 32, 33, and 34 are formed in the housing 1 and communicate with each suction passage chamber 15, and the sub-suction chambers 32, 33, and 34 communicate with the suction chamber 35 within the housing. The suction chamber 35 communicates with the suction chamber of the rear housing 29 through the suction communication hole 36 of the side plate 25, and a suction connection port 38 is opened in the suction chamber so that refrigerant is supplied from an evaporator (not shown). It's getting old. In this compressor, throttle valves 42 and 43 are provided between the sub-suction chambers 32 and 34 other than 33 and the suction chamber 35 for conducting or blocking the two chambers 32, 34 and 35. It is provided.

Next, the throttle valves 42 and 43 are
This will be explained based on the diagram.

In FIG. 6, reference numeral 44 denotes a throttle valve cylinder made of iron, and this cylinder 44 is press-fitted into the suction gas passage 40 (41) via an O-ring 45. This cylinder 44 has an intake gas passage 40 (4
1) and the sub-suction chamber 32 (3).
4) is formed. 48
is a bypass valve body made of aluminum, and is slidably housed in the cylinder 44 via a piston ring 49. The tip 48 of this valve body 48
By abutting the valve seat surface 44a of the cylinder 44, the throttle hole 46 and the communication hole 47 can be shut off. 50 is a body portion that fixedly supports the throttle valve cylinder 44, and this body portion 50 has a threaded portion 50a formed to protrude into the cylinder 44, and a valve body support portion 51 is screwed onto the threaded portion 50a. ing. Further, the valve body 4
A spring seat 52 is fixed to the valve support 8 by a circlip 53, and a spring 54 is interposed between the spring seat 52 and the flange 51a of the valve support 51. Therefore, the valve body 48 receives an upward biasing force in the drawing from the spring 54.

Further, a pressure chamber 56 is formed between the body portion 50 and the lid portion 55, and the pressure in this pressure chamber 56 is applied to the back surface of the valve body 48 through a pressure guiding hole 57. ing. Furthermore, a high pressure introduction hole 58 for introducing high pressure into the pressure chamber 56 and a low pressure introduction hole 59 for introducing low pressure into the pressure chamber 56 are formed in the body portion 50 . The high pressure introduction hole 58 communicates with the central sub-discharge chamber 23 via a high pressure introduction passage 60 bored in the housing 1 (as shown in FIG. 4), and the low pressure introduction hole 59 communicates with the low pressure introduction passage 60 bored in the housing 1. It communicates with the suction pressure chamber 35a (35b) via a passage 61. Note that the suction chamber 35 and the suction pressure chamber 35a (35b) are connected to the pressure equalization groove 3.
5c (35d) ensures constant pressure.

Further, the high pressure introduction passage 60 is formed of a circular hole with a diameter of about 5 mm, and a metal filter 62 is filled in the middle of the passage 60 to remove foreign matter. 63 is a blind plug that closes the open end 59a of the low pressure introduction hole 59. 64 is a plunger disposed facing the opening 59b of the low pressure introduction hole 59 in the pressure chamber 56;
is a spring interposed between the plunger 64 and the core portion 66 and presses the plunger 64 toward the opening 59b; 67 is an excitation coil that drives the plunger 64; it is excited when a signal current is applied from the lead wire 68; The plunger 64 is then sucked upward in the figure. At that time, a pressure equalizing hole 64a is formed in the plunger 64 so that the plunger 64 can be moved with a small magnetic force.

The excitation coil 67 and the like are housed in a cover 69, which includes the cover 69, the lid part 55, and the body part 5.
0 is fixed to the housing 1 with bolts 70.

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

The compressor is disposed under the floor of the bus together with the vehicle running engine, and when an electromagnetic clutch (not shown) is engaged and the engine is started, the shaft 6 rotates under the driving force of the engine. With this rotation, the piston 10 receives a reciprocating driving force from the driving member 9, and the cylinders 2a, 2b, 3a, 3b,
It reciprocates within 4a and 4b. Therefore, the working chamber 78 in the cylinder repeatedly increases and decreases in volume, and in the suction stroke where the volume increases, the refrigerant is sucked from the evaporator side through the connection port 38 - suction chamber - suction passage hole 38 - suction chamber 35 - Sub-suction chamber 32, 33, 34-
The air is sucked into the working chamber 78 through the suction passage chamber 15, the suction hole 18, and the suction valve 20. Conversely, in the discharge stroke in which the volume of the working chamber 78 decreases, the refrigerant discharged from the working chamber 78 through the discharge hole 19 and the discharge valve 21 flows through the discharge passage chamber 16 - sub-discharge chambers 22, 23, 24 - discharge communication hole. 26, 27, 28 - passes through the discharge chamber 30 and is discharged from the discharge connection port 31 to the condenser side.

The compressor operates as described above, but when the temperature inside the vehicle is high and the cooling load is large, all cylinders 2
Piston 1 with a, 2b, 3a, 3b, 4a, 4b
0 performs compression and discharge work.

That is, the lead wires 68 of the throttle valves 42 and 43
The throttle valves 42 and 43 open the intake gas passages 40 and 41. When the lead wire 68 is energized, the coil 67 is excited and attracts the plunger 64, as shown in FIG.
9 is exposed to the pressure chamber 56. As a result, the pressure inside the pressure chamber 56 is reduced to the low pressure introduction hole 59,
The suction pressure chamber 35a (35
Equalize the pressure with b). Therefore, the throttle valve body 48
The back pressure becomes almost equal to the pressure in the suction chamber 35, and the valve body 48 is separated from the suction gas passage 46 by the biasing force of the spring 54, so that the refrigerant gas flows into the sub suction chamber 22 (24). ) from the suction passage chamber 15 to the working chamber 78.

However, if the compressor is operated at full capacity when the refrigerant load is small, such as when the room temperature of the vehicle is relatively low or when there is no sunlight, the refrigerant capacity will be used up and overcooling will occur. For this reason, it is possible to control the operating time of the compressor by intermittent operation of the electromagnetic clutch, but especially in large capacity compressors such as bus compressors, a very large load is applied to the electromagnetic clutch when connected. Also, from the viewpoint of the durability of the electromagnetic clutch, it is undesirable to repeat the disconnection.

Furthermore, even when the engine is under a large load, such as when the vehicle is rapidly accelerating, when the vehicle is on a hill, or when the engine is started, it is undesirable to operate the compressor at full capacity, which places an excessive load on the engine.

Therefore, in the compressor of the present invention, in the above case, no signal current is applied to the lead wires of the throttle valves 42, 43, and as shown in FIG.
I am trying to close it. In this case, plunger 6
4 closes the opening 59b of the low pressure introduction hole 59 under the urging force of the spring 65, and only the high pressure introduction hole 58 opens in the pressure chamber 56. Therefore, the high pressure within the sub-discharge chamber 23 is applied to the pressure chamber 56, and this pressure is transmitted to the back pressure of the throttle valve body 48 through the pressure guiding hole 57. Therefore, the valve body 48 is pressed against the valve seat surface 44a by the pressure of the discharged refrigerant in the sub-discharge chamber 23, thereby blocking the intake gas passage.

As a result, the suction refrigerant gas in the suction chamber 35 is completely cut off from the sub-suction chamber 32 (33), and the cylinder 2
In a, 2b, 4a, and 4b, the refrigerant is no longer sucked and compressed, making it possible to adjust the cooling capacity and reduce horsepower.

In this case, the throttle valves 42 and 43 do not operate at the same time, but depending on the cooling load, only one of the bypass valves 43 operates when the surplus cooling capacity is small, and only when the surplus cooling capacity becomes large. Valves 42 and 43 are adapted to operate.
However, when operating only one throttle valve 43, the opening position 38a of the suction connection port 38 (the fourth
The throttle valve 43 near the corresponding position (the corresponding position is indicated by a broken line in the figure) is operated to open.

When the suction gas passages 40, 41 are closed in this way, the pressure in the sub-discharge chambers 22, 24 is significantly reduced, and as a result, the discharge communication holes 26, 28 are closed by the check valves 71, 72. Therefore, in the compressor, only the refrigerant discharged into the sub-discharge chamber 23 is discharged from the discharge chamber 30 toward the condenser. However, in this compressor, the discharge valve 21 also prevents the discharged refrigerant from flowing back, so check valves 71 and 7 may be used as necessary.
2 may be abolished.

In addition, in the above-mentioned embodiment, the throttle valves 42, 4
However, when the plunger 64 opens the low pressure introduction hole 59, the refrigerant discharged from the sub-discharge chamber 23 flows into the high pressure introduction passage, albeit in small amounts. 6
0 - High pressure introduction hole 58 - Pressure chamber 56 - Low pressure introduction hole 5
9-Low pressure introduction passage 61-Suction pressure chamber 35a (35b)
It leaks into the suction chamber 35 through the. For that reason,
This means that the entire refrigerant cannot be discharged to the cylinders 3a and 3b, which are supposed to work effectively. Therefore, in order to prevent such a situation from occurring, the throttle valves 42 and 43 may be arranged as shown in FIG. 8 so that when the plunger 64 opens the low pressure introduction hole 59, the high pressure introduction hole 58 is closed at the same time. .

That is, the high pressure introduction holes 77 and 78 are formed in the lid part 55 and the plunger 64, and when the plunger 64 closes the low pressure introduction hole opening 59b (see FIG. 9), both the introduction holes 77 and 78 communicate with each other. The discharge refrigerant pressure is introduced into the pressure chamber 56, and the plunger 64
moves upward in the figure to open the low pressure introduction opening 59b (see Fig. 10), both the introduction holes 77, 7
8 to prevent discharge pressure from being introduced due to misalignment of the opening. In this embodiment, the side opening of the high pressure introduction hole 78 of the plunger 64 has a groove 79 extending in the circumferential direction so that the introduction holes 77 and 78 can communicate with each other no matter which position the plunger 64 rotates. (see Figure 11).

Further, in the above embodiment, the cylinders 2a, 2b,
Although a six-cylinder compressor is shown in which three sets of cylinders 3a, 3b, 4a, and 4b are installed, it goes without saying that the present invention is widely applicable to multi-cylinder compressors having two or more cylinders. Furthermore, in addition to the above-mentioned reciprocating type compressor, it is also applicable to a swash plate type compressor and the like. Furthermore, the compressor of the present invention can be used for applications other than air conditioning systems for buses, such as indoor air conditioning.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the compressor of the present invention, and shows a cross-sectional shape taken along the - line in FIG. 3.
Fig. 2 is a plan view showing the housing shown in Fig. 1, Fig. 3 is a side view of Fig. 1, and Fig. 4 is a - of Fig. 1.
5 is a front view showing the side plate shown in FIG. 1, FIGS. 6 and 7 are sectional views showing the throttle valve shown in FIG. 4, and FIG. 8 is a sectional view showing the throttle valve shown in FIG. 4. A sectional view showing another example of a throttle valve,
9 and 10 are sectional views showing the main parts of FIG. 8, and FIG. 11 is a sectional perspective view showing the main parts of the bypass valve shown in FIG. 9. 1...Housing, 2a, 2b, 3a, 3b, 4
a, 4b... Cylinder, 6... Shaft, 9... Drive member, 10... Piston, 22, 23, 24... Sub-discharge chamber, 30... Discharge chamber, 32, 33, 34... Sub-suction chamber, 35... Suction chamber, 40 , 41... Suction gas passage;
42, 43...Throttle valve.

Claims (1)

[Scope of Claims] 1. A housing, a shaft rotatably supported by the housing, a drive member disposed within the housing and converting rotational motion of the shaft into reciprocating motion, and a drive member disposed within the housing that converts the shaft into reciprocating motion. a plurality of cylinders formed in a radial shape with the center at the center; a plurality of pistons that reciprocate within the cylinders in response to the driving force of the drive member; and a sub-suction chamber formed within the housing and supplying refrigerant to each cylinder. a suction chamber formed within the housing and communicating with each sub-suction chamber so that refrigerant can be supplied; a sub-discharge chamber formed within the housing and into which compressed refrigerant is discharged from each cylinder; and a sub-discharge chamber formed within the housing. a discharge chamber that communicates with each sub-discharge chamber so that the refrigerant can collect; and a position in the housing from the suction chamber to the sub-suction chamber and into the cylinder;
and a throttle valve disposed in a portion communicating with a predetermined part of the cylinders among the plurality of cylinders to conduct and cut off the flow of suction refrigerant, the throttle valve being disposed in a portion between the cylinders within the housing. A pressure chamber is formed on the back surface of the throttle valve, and a high pressure introduction passage communicates between the pressure chamber and the sub-discharge chamber, and a low pressure passage communicates between the pressure chamber and the suction chamber. An introduction passage is formed,
The variable capacity compressor further includes a plunger that controls the pressure inside the pressure chamber based on an electric signal. 2. The variable capacity according to claim 1, wherein a check valve is disposed between the sub-discharge chamber and the discharge chamber to allow the refrigerant to flow only from the sub-discharge chamber side to the discharge chamber side. compressor. 3. The variable capacity compressor according to claim 1, wherein the plunger is arranged opposite to the opening of the low pressure introduction passage and opens and closes the low pressure introduction passage. 4. The variable capacity compressor according to claim 1 or 2, wherein the plunger switches between the high pressure introduction passage and the low pressure introduction passage.