JPS624705Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a capacity control valve device that controls the capacity of a compressor equipped with multiple cylinders, and is particularly designed to prevent wear and tear on the valve body. be.

(Prior Art) Generally, for example, in a multi-cylinder fully hermetic compressor, a plurality of cylinders are divided into a first cylinder group and a second cylinder group, and a first suction chamber and a second cylinder communicate with the first cylinder group. A second suction chamber communicating with the two cylinder groups is communicated with the second cylinder group through a suction hole, and an unloading device is disposed in the suction hole. Loading operation is carried out by supplying intake gas to all cylinders, while during unloading, the unloading device is operated to supply intake gas only to the first cylinder group, and the second cylinder group is closed for intake. Capacity control is performed by unloading.

By the way, conventionally, the unloading device includes a cylinder fixed to a frame, a piston slidably inserted into the cylinder, and a peripheral portion of the suction hole connected to the piston to open and close the suction hole. a valve body that can be seated on a valve seat provided in the cylinder, a pressure pipe that supplies pressure gas to the back of the piston of the cylinder, and a spring that biases the valve body in the valve opening direction,
A three-way valve is installed in the pressure pipe to selectively supply high-pressure gas or low-pressure gas to the pressure pipe, and during loading, the three-way valve supplies low-pressure gas to the back of the piston of the cylinder via the pressure pipe to mix it with the suction gas. Eliminating the differential pressure, the valve body is opened by the spring force to open the suction hole, while at the time of unloading, the three-way valve supplies high-pressure gas to the back of the cylinder piston via the pressure pipe, and the suction gas and The differential pressure causes the valve body to close against the force of the spring, thereby closing the suction hole.

(Problems to be Solved by the Invention) However, in the conventional unloading device, when unloading, the valve body collides with the valve seat of the suction hole due to the pressure difference and is closed. There was a problem that the valve body was damaged by friction within a short period of time and lacked durability. In addition, the pressure gas (high pressure gas) that acts on the back of the piston in the cylinder tends to leak, and if the tight fit between the cylinder and piston is increased to reduce this gas leakage, the sliding resistance will increase, causing the valve body to become loose during loading. There was a problem that a large spring force was required for the spring that operated the opening, and the large spring was required, resulting in a large structure.

The present invention has been made in view of this point, and in the capacity control valve device such as the above-mentioned unloading device, when the valve body is seated on the valve seat during unloading, the sealing portion between the valve body and the valve seat is In addition, by providing a separate valve seat part to prevent gas leakage of high-pressure gas acting on the back of the piston, the impact force caused by the valve element being seated on the valve seat when the valve element is closed can be shared by the above-mentioned separate valve seat part. In addition to preventing friction damage to the valve body and improving its durability, the separate valve seat part reduces gas leakage and improves sealing performance, and it operates without increasing the size of the structure. The present invention aims to provide a capacity control valve device for a multi-cylinder compressor with excellent stability.

(Means for solving the problem) In order to achieve this objective, the solution taken by the present invention is to connect a plurality of cylinders directly to the suction side, as shown in FIGS. 1 and 2. The cylinder group is divided into a first cylinder group that communicates with the suction side through an intake hole 31 provided in the frame 3, and a second cylinder group that communicates with the intake side through an intake hole 31 provided in the frame 3.
The target is a multi-cylinder compressor that performs capacity control by controlling the opening and closing of 1. Furthermore, a valve seat 31a formed at the opening periphery of the suction hole 31
A cylinder 38 is provided in the frame 3 on the side facing the valve seat 31a with its center axis aligned with the center line of the suction hole 30, and a cylinder 38 is fitted into the cylinder 38 so as to be slidable back and forth in the axial direction. A piston 39 partitions the inside of the cylinder 38 to form a suction pressure chamber 38b communicating with the suction side at the front and a back pressure chamber 38c at the back.
and a valve seat 31 of the suction hole 31 connected to the front part of the piston 39 to open and close the suction hole 31.
the valve body 41 that can be seated in the suction pressure chamber 38b;
A spring 43 is compressed inside and urges the piston 39 in the direction in which the valve body 41 opens, and a spring 43 is connected to the back pressure chamber 38c, and the back pressure chamber 38c has a low pressure when loading and a high pressure when unloading. A pressure pipe 42 for supplying pressure gas is provided, and the high pressure gas supplied to the back pressure chamber 38c and the suction pressure chamber 38 at the time of unloading are provided.
The valve body 41 is configured to close due to the pressure difference between the suction gas and the suction gas of the piston 39, and a contact portion 39a is provided on the periphery of the end of the piston 39 on the side of the suction pressure chamber 38b.
A valve body 41 is provided on the inner peripheral wall of the cylinder 38.
The structure is such that an auxiliary valve seat 38a is provided, which the abutting portion 39a abuts and seals at the forward end position of the piston 39, where the piston 39 is seated on the valve seat 31a.

(Function) With the above configuration, in the present invention, when unloading, the valve body 41 seats and contacts the valve seat 31a of the suction hole 31 and closes, and at the same time, the contact portion 39a of the piston 39 closes the valve seat 31a of the cylinder 38. By contacting the seat 38a, the impact force generated when the valve body 41 contacts the valve seat 31a is shared and halved. Furthermore, when the valve body 41 is closed, another valve seat is formed by the abutment of the contact portion 39a against the auxiliary valve seat 38a.
Gas leakage of high pressure gas introduced into the back is reduced,
Sealing performance can be improved. In addition, as the sealing performance is improved, the sliding resistance between the cylinder 38 and the piston 39 can be reduced, and the spring force of the spring 43 that biases the valve body 41 in the valve opening direction can be reduced.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

1 and 2 show an example in which the compressor is applied to a completely hermetic six-cylinder compressor, and 1 is a hermetic casing, and an external suction pipe 2 is connected to the internal space of the casing 1. Possibly connected. Reference numeral 3 denotes a frame disposed inside the casing 1, and the frame 3 has protrusions 4 protruding from three locations on its outer periphery and springs attached to support brackets 5 protruding from three locations on the inner circumferential wall of the casing 1. 6 and is elastically supported within the casing 1. A motor 9 consisting of a rotor 7 and a stator 8 is mounted and fixed on the frame 3, and the motor 9 is connected to a rotating shaft 10 disposed in the vertical direction.
is rotatably supported via an upper bearing metal 12 passing through an upper bearing 11 which is provided in the center of the frame 3 to protrude in the vertical direction. Furthermore, a crankshaft 13 is connected to the lower part of the rotating shaft 10 in the vertical direction (axial direction), and the lower end of the crankshaft 13 is rotatably supported by a lower bearing 14 provided at the lower end of the frame 3. ing. In addition, 15 is the crankshaft 13
An oil hole 16 drilled in the center of the lower end of the oil hole 16 is an oil supply hole bored eccentrically from the oil hole 15 through the crankshaft 13 and the rotating shaft 10, and the oil supply hole 16 communicates with the oil hole 16. It communicates with the oil hole 15 through the hole 17, and the oil supply hole 1
6 has supply ports 18, 18, 18 opened in the radial direction at positions facing each of the upper bearing 11, the lower bearing 14, and the bearing portion of the crankshaft 13. Oil is supplied to each bearing 11, 14 and the bearing portion of the crankshaft 13.

Further, 19 is a cylindrical motor cover that covers the motor 9, and the lower end of the motor cover 19 is hermetically fixed to the outer periphery of the upper end of the frame 3. Suction ports 20, 20 are opened in the upper part of the motor cover 19, and suction ports 20, 20 are opened from the external suction pipe 2 to the casing 1.
The suction gas supplied to the internal space of the
0, 20 into the upper space in the motor cover 19, and then into the cylinders 22 in the frame 3, which will be described later, through the suction passage 21 formed in the rotor 7 of the motor 9. There is.
Note that 54 is a through hole for the electric wire of the motor 9.

On the other hand, in the frame 3, first to third
Cylinders 22... and fourth to sixth cylinders 22... are formed radially and at equal pitches at high positions, and each cylinder 22... has a piston 2 inside it.
3 is slidably inserted in the radial direction, and each piston 23 is connected to the crankshaft 13 via a connecting rod 24.
The cylinders 22 are connected to each other so that the pistons 23 reciprocate in the radial direction due to the rotation of the crankshaft 13, thereby compressing gas within the cylinders 22.

Further, in the frame 3, an annular first suction chamber 25 communicating with the suction passage 21 is formed concentrically with the rotating shaft 10.
An annular second suction chamber 27 is formed concentrically on the outer periphery of the suction chamber 5 with a partition wall 26 interposed therebetween. First suction ports 28 are opened in the upper side wall of the first suction chamber 25 at positions facing the fourth to sixth cylinders 22 .
The fourth to sixth cylinders pass through the valve seat 29 provided in each of the cylinders 22 and each cylinder head cover 30.
The cylinders 22... are communicated with each other. Further, a suction hole 31 is opened in the intermediate side wall of the first suction chamber 25, that is, the partition wall 26, and the suction hole 31 allows the first suction chamber 25 and the second suction chamber 27 to communicate with each other. Frame 3, first to third cylinders 2
A second suction port 3 is provided through the valve seat 29 provided in each of the cylinders 2 and each cylinder head cover 30.
2 to the first to third cylinders 22. In addition, 33 connects the first suction chamber 25 to the fourth to
A partition wall 34 that partitions an opposing portion facing each first suction port 28 communicating with the sixth cylinder 22 and the other non-opposing portion so as to be able to communicate with each other at the above-mentioned position.
is a shielding plate for sealingly closing the upper portions of the first suction chamber 25 and the second suction chamber 27, and the shielding plate 34 includes a shielding plate that faces each non-opposed portion of the first suction chamber 25. A communication port 35 that opens is provided. Further, 36 is a liquid discharge hole whose one end opens at a certain height from the bottom of the non-opposed portion of the first suction chamber 25 and whose other end communicates with the outside of the frame 3, and is a liquid refrigerant hole that collects in the non-opposed portion. is discharged to the outside of the frame 3.

Further, an unloading device 37 for opening and closing the suction hole 31 is disposed in the suction hole 31. That is, as shown in detail in FIG. 2, the unloading device 37 includes a valve seat 31a formed around the opening of the suction hole 31, and a valve seat 31a formed on the frame 3 on the side opposite to the valve seat 31a. A cylinder 38 is provided with its center axis aligned with the center line of the suction hole 31, and the cylinder 38 is fitted into the cylinder 38 so as to be slidable back and forth in the axial direction.
a piston 39 that forms a suction pressure chamber 38b communicating with the suction side via the piston and a back pressure chamber 38c at the back;
The suction hole 31 is connected to the front part of the piston 39 via a rod 40 to open and close the suction hole 31.
A valve element 41 that can be seated on the valve seat 31a of It includes a spring 43 that biases the piston 39 in the direction in which the valve body 41 opens (towards the back pressure chamber). The pressure pipe 42 is provided with a three-way valve 44 that switches and supplies high-pressure gas or low-pressure gas to the pressure pipe 42. During loading, the three-way valve 44 supplies low-pressure gas to the cylinder 38 through the pressure pipe 42.
is supplied to the back pressure chamber 38c at the back of the piston 39,
By equalizing the pressure with the suction gas pressure in the suction pressure chamber 38b, the spring force of the spring 43 operates the valve body 41 to open the suction hole 31, thereby opening the first suction chamber 2.
5 and the second suction chamber 27, and thus the first
~The sixth all cylinders 22... are made to inhale suction gas and perform gas compression. On the other hand, when unloading,
A three-way valve 44 supplies high-pressure gas through a pressure pipe 42 to a back pressure chamber 38c at the back of the piston 39 of the cylinder 38.
The valve body 41 is seated on the valve seat 31a of the suction hole 31 against the spring force of the piston 43 due to the pressure difference between the suction gas in the suction pressure chamber 38b and the suction hole 31 is closed. By closing, the communication between the first suction chamber 25 and the second suction chamber 27 is closed, and thus the suction gas is inhaled only into the fourth to sixth cylinders 22 to perform gas compression. .

In the unloading device 37, the skirt end of the piston 39, that is, the suction pressure chamber 3
A contact portion 39a is provided on the periphery of the end portion on the side 8b. On the other hand, an auxiliary valve seat 38a is provided on the inner circumferential wall of the cylinder 38, with which the abutment portion 39a abuts at the forward end position of the piston 39, where the valve body 41 is seated on the valve seat 31a of the suction hole 31. Afterwards,
During unloading (when the valve body 41 closes), the valve body 41
Two valve seat portions are formed by the contact between the valve seat 31a of the suction hole 31 and the contact portion 39a of the piston 39 and the auxiliary valve seat 38a of the cylinder 38. In addition, 45 is piston 3
A piston ring is fitted around the outer periphery of 9, 46 is a cover, and 47 is an O-ring.

Further, each of the fourth to sixth cylinders 22 is provided with a first discharge port (not shown) passing through the valve seat 29 and the cylinder head cover 30, and each of the first discharge ports is connected to the first communication pipe 48. It is communicated with a discharge muffler 49 disposed in the upper part of the casing 1 via. Further, each of the first to third cylinders 22... is provided with a second discharge port (not shown) passing through the valve seat 29 and the cylinder head cover 30, and each of the second discharge ports is connected to a second communication pipe ( (not shown) to the first discharge ports of the corresponding adjacent fourth to sixth cylinders 22, respectively. Further, two discharge pipes 50 and 51 are connected to the discharge muffler 49, and after hanging down along the outer wall of the frame 3, the discharge pipes 50 and 51 curve the outer periphery of the lower bearing 14 of the frame 3. Both discharge pipes 50,5
1 is connected to one collective discharge pipe 53 via a joint 52, and the discharge pipe 53 is led out of the casing 1.

Although not shown, a suction valve and a discharge valve are mounted on the valve seat 29 to face the suction ports 28, 29 and the discharge port, respectively.

Next, to describe the operation of the embodiment, the suction gas supplied from the external suction pipe 2 to the internal space inside the casing 1 is transferred to the suction port 2 of the motor cover 19.
After passing through the upper space in the motor cover 19 and the suction passage 21, the air is sucked into the first suction chamber 25 through the communication hole 35 of the shielding plate 34. The suction gas sucked into the first suction chamber 25 is transferred to the fourth to sixth cylinders 2 through the first suction port 28 during loading.
2... and the unloading device 37
The opening operation causes the second suction chamber 27 to pass through the suction hole 31.
The gas flows through the second suction port 32 and is also sucked into the first to third cylinders 22 . . . , and gas compression is performed in all the cylinders 22 . On the other hand, during unloading, due to the closing operation of the unloading device 37, gas is sucked into only the fourth to sixth cylinders 22... through the first suction port 28, and gas is compressed in the fourth to sixth cylinders 22... be exposed. After that, the fourth to sixth cylinders 2
2, the gas compressed in the first discharge port and the first
While being collected in the discharge muffler 49 via the communication pipe 48, the gas compressed in the first to third cylinders 22... is transferred to the adjacent corresponding fourth to sixth cylinders via the second discharge port and the second communication pipe. The gas from each of the fourth to sixth cylinders 22 joins with the gas from each of the fourth to sixth cylinders 22 at each first discharge port of the cylinder 22, and then the discharge muffler 4
9 and then two discharge pipes 50, 5
1 into a collective discharge pipe 53 and led out of the casing 1.

In this case, in the unloader device 37, at the time of unloading, the valve body 41 is seated in contact with the valve seat 31a of the suction hole 31 and is closed, and at the same time,
When the abutting portion 39a of the piston 39 abuts the auxiliary valve seat 38a of the cylinder 38, the valve body 4
1 will share the impact force when it comes into contact with the valve seat 31a, which will reduce it by half.
Friction damage to the valve body 41 can be prevented and its wear can be significantly reduced, thereby improving durability. Furthermore, when the valve body 41 is closed, another valve seat is formed by the abutment of the contact portion 39a against the auxiliary valve seat 38a, so that the high pressure gas introduced into the back of the piston 39 of the cylinder 38 may leak. can be reduced and sealing properties improved. Moreover, with this improved sealing performance, it becomes possible to reduce the sliding resistance between the cylinder 38 and the piston 39, and the spring force of the spring 43 that biases the valve body 41 in the valve opening direction can be reduced. It is possible to reduce the size of the spring 43 and, in turn, to reduce the size of the entire device.

In the above embodiment, the case where the present invention is applied to a six-cylinder fully hermetic compressor has been described, but the present invention can also be applied as a capacity control valve device in a multi-cylinder compressor having at least two or more cylinders.

(Effect of the invention) As explained above, according to the invention, a plurality of cylinders are connected to the first cylinder group that directly communicates with the suction side, and the suction hole 31 provided in the frame 3 to the suction side. The intake hole 3 is divided into a second group of cylinders communicating through the
In a multi-cylinder compressor in which capacity control is performed by controlling the opening and closing of a valve seat 31, a valve seat 31a formed at the opening periphery of the suction hole 31;
The central axis is inserted into the suction hole 3 in the frame 3 on the side opposite to 1a.
Cylinder 38 provided to match the center line of 0
A suction pressure chamber 38b is fitted into the cylinder 38 so as to be slidable back and forth in the axial direction, and partitions the inside of the cylinder 38, with a suction pressure chamber 38b communicating with the suction side at the front and a back pressure chamber 38 at the back.
a valve body 41 connected to the front part of the piston 39 and seatable on the valve seat 31a of the suction hole 31 to open and close the suction hole 31; A spring 43 is compressed to bias the piston 39 in the direction in which the valve body 41 opens, and a spring 43 is connected to the back pressure chamber 38c and has a low pressure when loaded into the back pressure chamber 38c.
A pressure pipe 42 is provided for supplying high-pressure gas during unloading, and the valve body 41 is operated to close by the differential pressure between the high-pressure gas supplied to the back pressure chamber 38c and the suction gas in the suction pressure chamber 38b during unloading. Further, an abutting portion 39a is provided on the periphery of the end of the piston 39 on the side of the suction pressure chamber 38b, and the valve body 41 is attached to the inner circumferential wall of the cylinder 38 against the valve seat 31a.
By providing an auxiliary valve seat 38a with which the abutting portion 39a abuts and seals at the forward end position of the piston 39 seated on the piston 39, the impact force when the valve body is seated is halved and its sagging is significantly reduced. As a result, durability can be greatly improved. Moreover, it is possible to improve the sealing performance against gas leakage, so it is possible to significantly reduce gas leakage and achieve high efficiency, as well as to make the structure more compact and to improve operational stability. It is possible.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view showing the overall structure, and FIG. 2 is an enlarged view of the main part of FIG. 1. 3... Frame, 31... Suction hole, 31a... Valve seat, 37... Unloading device, 38... Cylinder, 38a... Auxiliary valve seat, 38b... Suction pressure chamber,
38c...back pressure chamber, 39...piston, 39a...
... Contact portion, 41 ... Valve body, 42 ... Pressure pipe, 43
……spring.

Claims (1)

[Scope of utility model registration request] The plurality of cylinders are divided into a first cylinder group that communicates directly with the suction side and a second cylinder group that communicates with the suction side through a suction hole 31 provided in the frame 3. In a multi-cylinder compressor that performs capacity control by controlling opening and closing, a valve seat 31a formed at the periphery of the opening of the suction hole 31;
A cylinder 38 is provided in the frame 3 on the side facing the valve seat 31a with its center axis aligned with the center line of the suction hole 30, and a cylinder 38 is fitted into the cylinder 38 so as to be slidable back and forth in the axial direction. A piston 39 that partitions the inside of the cylinder 38 and forms a suction pressure chamber 38b in the front part communicating with the suction side and a back pressure chamber 38c in the back part,
A valve body 41 is connected to the front part of the piston 39 and can be seated on the valve seat 31a of the suction hole 31 to open and close the suction hole 31; a spring 43 that biases the body 41 in a direction to open the valve; and the back pressure chamber 3.
8c, and supplies pressure gas of low pressure to the back pressure chamber 38c during loading, and high pressure gas during unloading, and the high pressure gas supplied to the back pressure chamber 38c during unloading and the suction pressure chamber. The valve body 41 is configured to close due to the pressure difference between the intake gas and the piston 39b.
A contact portion 39a is provided on the periphery of the end on the side of the suction pressure chamber 38b, and the contact portion 39a contacts the inner peripheral wall of the cylinder 38 at the forward end position of the piston 39 where the valve body 41 is seated on the valve seat 31a. A capacity control valve device for a multi-cylinder compressor, characterized in that an auxiliary valve seat 38a is provided for sealing.