JPS6259237B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reciprocating compressor used in air conditioners, refrigerators, and the like.

Conventionally, in a reciprocating compressor, in order to control the capacity of the compressor and to perform power-saving control, four or more cylinders and the discharge gas passage were connected through piping, and a valve was opened and closed during the piping. Interpose a valve (4
In the case of cylinders, a so-called discharge gas bypass system is known in which three of the four pipes in total have on-off valves interposed in each pipe, but such a conventional structure has a complicated structure. Moreover, it had the disadvantage of poor energy effective ratio (so-called EER) and large power loss.

In addition, the cylinders of 4 or more cylinders and the intake gas passage are connected through piping, and on-off valves are inserted in the piping (in the case of 4 cylinders, on-off valves are installed in 3 of the 4 piping in total). A so-called suction gas closed type with a conventional structure (interposed) is known, and while such a conventional structure has an improved energy efficiency ratio and reduces power loss compared to a discharge gas bypass type, The same number of valves as the discharge gas bypass method is required, and the piping structure is also complicated, as in the same method.

One known example that solves these problems is Japanese Utility Model Publication No. 50-37047.

That is, in a reciprocating compressor having four cylinders, the suction chamber formed around the crank bearing of the frame forming the cylinder is divided into four sections by four partition walls centered on the axis of the crank bearing. The partition wall is divided into a total of four chambers, each cylinder is communicated with each chamber, and an on-off valve is provided in each of the two partition walls located on a straight line. A compressor is known in which two adjacent chambers are communicated with each other by the on-off valve and are disconnected to control the capacity of the compressor.

However, although such a known example can simplify the piping structure, since the movement direction of the on-off valve is an axial direction parallel to the axis of the crankshaft, it is difficult to process the valve hole etc. It is necessary to divide the frame into upper and lower parts, in which case centering and alignment between the crankshaft bearing fitting part formed in the upper frame and the cylinder formed in the lower frame is easy. However, in order to accurately assemble the crankshaft and piston into these upper and lower frames, there are problems with machining accuracy and assembly, such as the need to finish the joint surfaces between the upper and lower frames with high precision. Not only is there a problem with installation work, but the structure is complicated, such as the need to install multiple on-off valves depending on the number of cylinders, and the trouble of having to disassemble the upper and lower frames each time they are installed or removed. The annoyance of this was overwhelming.

Especially in this type of suction closed unloading structure, the EER (Energy Effective Ratio) during unloading operation has a strong correlation with the degree of vacuum in the closed chamber.
In order to improve EER, it is necessary to prevent gas leakage into the vacuum chamber, and when assembling the upper and lower divided frames, it is necessary to prevent gas from leaking into the vacuum chamber. Since coaxiality is required, it is not possible to insert gaskets into the joint surface, and therefore high precision is required on the joint surface to prevent leakage, but on the other hand, the amount of leakage is not constant and the quality is unstable. The problem arose that it didn't.

The present invention was invented to eliminate such drawbacks, and the purpose of the present invention is to divide the suction chamber into two concentric circles by a partition wall, and to divide the suction chamber into two concentric circles formed by dividing the suction chamber into two concentric circles. By providing one on-off valve that connects and disconnects the chambers in the radial direction on the partition wall, the frame can be formed into a single piece, and the capacity of the compressor can be controlled with the single on-off valve. The reason is that there is no need for a complicated piping structure.

The structure of the present invention is that, in a reciprocating compressor having at least four or more cylinders, a suction chamber formed around a crank bearing of a frame forming the cylinder is separated into a first space by a partition wall concentric with the bearing. divided into a chamber and a second chamber, and at least two or more appropriate cylinders among the cylinders are placed in the first chamber,
The remaining at least two or more cylinders are connected to the second chamber, and one opening/closing valve is provided in the partition wall in the radial direction to open and close the first chamber and the second chamber, Compression is performed in all cylinders when the on-off valve is operated to connect the first chamber and the second chamber, and the first and second chambers are disconnected by operating the on-off valve. At the same time, the compression action is performed using half the number of cylinders compared to the total number of cylinders, and the suction chamber is divided into a first chamber and a second chamber by a partition wall concentric with the crank bearing, so that the on-off valve can be moved in the radial direction. By making it possible to install the system in one piece, making it possible to integrally mold the frame, and by controlling the capacity with a single on-off valve, the need for a complicated piping structure was eliminated.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

The reciprocating compressor shown in FIG.
The refrigerant is installed in a sealed housing 4 through the suction pipe 5 connected to the housing 4 through the suction hole 46. Furthermore, it is of a so-called low-pressure dome type in which it is sucked into a compression mechanism 2, compressed, and discharged into a discharge pipe 7.

On the other hand, FIG. 2 is an enlarged sectional view of the main part of FIG. . That is, the crankshaft 14 is supported by an upper crank bearing 11 formed at the center of the upper part of the frame 10 and a lower crank bearing 13 formed on the cover plate 12 fixed to the lower surface of the frame 10.
Around the crank pin 15 of the crankshaft 14, as shown in FIG.
A large number of cylinders 16a, 16b, 16
c, 16d, 16e, and 16f are formed. Although only two cylinders 16a, 16d are shown in FIG. 2, these are six cylinders 16a, 16b, 16c, 1 as shown in FIG.
6d, 16e, and 16f, a group of three cylinders 16a, 16b, and 16c is formed in the upper stage, and a group of the remaining three cylinders 16d, 16e, and 16f is formed in the lower stage.

Further, each of these cylinders 16a to 16f is formed on a radial line of 60 degrees with the crankshaft 14 as the center, and the upper cylinder 16a,
16b, 16c between the lower cylinder 16
The pistons 17a, 17b, 17c, 17d, 1 are formed in such a way that the pistons 17a, 16e, and 16f are interposed therein, and are provided in each of the cylinders 16a to 16f.
7e and 17f are supported by the crank pin 15, respectively.

Further, as shown in FIG. 2, the cylinders 16a to 1
Two large and small annular grooves 19 and 20 are concentrically formed in the frame 10 so as to wrap around the crankshaft 14 at the upper part of the cylinder 16a to 16f.
A suction chamber 43 formed around the upper crank bearing 11 of the frame 10 forming the frame 6f is divided into a first chamber 20a and a second chamber 19a by a cut wall 27 concentric with the crank bearing 11. . Here, the second chamber 19a is formed in a sealed manner by fixing a ring-shaped lid member 21 to the groove edge opening of the outer annular groove 19.

Furthermore, as shown in FIG. 3, a first chamber 20a formed by an inner annular groove 20 and each upper cylinder 1
6a to 16c are respectively connected to suction valves 22, 22, 2.
On the other hand, the outer sealed second chamber 19a and each of the lower cylinders 16d to 16f are communicated via suction valves 23, 23, and 23, respectively.

Furthermore, an annular refrigerant discharge passage 24 is formed in the frame 10 at the lower part of each of the cylinders 16a to 16f, and the refrigerant discharge passage 24 and the upper and lower cylinders 16a, 16b, 16c, 16
d, 16e, and 16f respectively as discharge valves 25...2
6..., and also connects the refrigerant discharge passage 24 and the discharge pipe 7.

Furthermore, as shown in FIG. 3, a communication hole 28 is formed in the partition wall 27, and one spring offset type opening/closing valve 29 is provided in the communication hole 28 for opening and closing the second chamber 19a and the first chamber 20a. are arranged radially. The specific structure of this on-off valve 29 is as shown in FIG. A valve seat 31 is formed by the lip of the cylinder 30, and a lid 32 is provided on the outer opening of the cylinder 30, and the lid 32 and the cylinder 30
A piston chamber 33 is formed between the inner wall 30a,
The piston 34 provided in the piston chamber 33 and the valve 35 provided opposite to the valve seat 31 are connected to the wall 30.
The spring 3 is connected via a rod 36 penetrating through the piston chamber 33, and is connected to the spring 3 provided in the piston chamber 33.
7, the valve 35 is brought into close contact with the valve seat 31, and the second chamber 19 is closed.
A and the first chamber 20a are maintained in a normally closed state, while a pilot pipe 38 is connected to the lid 32. Here, the cylinder 30 has a hole 18 formed in the outer circumference of the frame 10.
(See Figure 3).

On the other hand, the electric motor 1 includes a cylindrical stator 40 whose lower end is press-fitted into the upper opening of the frame 10 in an airtight manner.
and the crankshaft 14 within the stator 40.
The rotor 41 is fixed to the upper end of the rotor 41 via a key 42.

The illustrated embodiment is configured as described above,
The action will be explained below.

In FIG. 2, the crankshaft 1 is
When 4 is rotated, 6 is rotated by its crank action.
Each of the pistons 17a-17f begins to reciprocate within each cylinder 16a-16f, respectively. In this case, as shown in FIG.
a, 16b, 16c are suction valves 22, 22, 2, respectively.
2, these upper cylinders 16a, 16b, 16c discharge refrigerant sucked from the first chamber 20a through discharge valves 25, 2.
5, 25 and the discharge pipe 7 via the refrigerant discharge passage 24.
However, the on-off valve 29 provided on the partition wall 27 keeps the second chamber 19a and the first chamber 20a closed by the force of the spring 37, and the second chamber 19a
do not communicate with the suction chamber 43, so the pistons 17d to 1 in each of the lower cylinders 16d to 16f
Even if 7f is reciprocating, the gas refrigerant only flows between the second chamber 19a and the three lower cylinders 17d to 17f.

In other words, in such a state, six cylinders 16a to 16
Three cylinders 16a, 16 half of f
This corresponds to a so-called unloading operation in which the discharge action is performed only by means b and 16c.

In particular, the six cylinders 16a to 16f are one group of cylinders 16a, 16b, 16c.
cylinders 16d, 16e, 16 of other groups
Since the cylinders 16a, 16b, 16c are arranged one by one for f, and unload control is performed by sealing one group 16a, 16b, 16c with the on-off valve 29, during the unload control, the remaining cylinders 16d, 16e, 16f
The pistons 17d, 17e, and 17f face each other at equal angles via the crankshaft 14. Therefore, the balance of forces on the crankshaft 14 is maintained.

When changing from a three-cylinder unload operation to a six-cylinder compression operation as described above, when high-pressure refrigerant is applied to the end surface of the piston 34 in the on-off valve 29 through the pilot pipe 38, the spring 37
The valve 35 separates from the valve seat 31 against the force, and the opening operation of the on-off valve 29 opens the second chamber 19a and the first chamber 2.
0a are in communication with each other, the refrigerant is also sucked into each of the three lower cylinders 16d, 16e, and 16f, and the refrigerant is also discharged into the discharge pipe 7 from each of these cylinders 16d to 16f. Even in this case,
Since the pistons 17a to 17f provided in each of the six cylinders 16a to 16f face each other on equiangular rays centered on the crankshaft 14, the balance of forces on the crankshaft 14 is maintained.

By the way, the suction chamber 43 is connected to the crank bearing 11.
It is divided into a first chamber 20a and a second chamber 19a by a concentric partition wall 27, which makes it possible to arrange the on-off valves 29 in the radial direction. As a result, there is no need to precisely process the joint surfaces of the frame, which is molded in two parts, such as the upper and lower parts, as in the past, and in addition, the capacity can be controlled by the single on-off valve 29. This has the effect of eliminating the need for a complicated piping structure.

In the illustrated embodiment, the on-off valve 29 is operated using the refrigerant pressure as a signal, but it is of course possible to use other appropriate signals such as electrical signals as the operating signal. . Further, in the embodiment, the on-off valve 29 is of a normally closed type, but it goes without saying that it may be of a normally open type and closed by an operation signal.

In addition, each of the upper cylinders 16a, 16b, 16
c into the outer second chamber 19a, and each lower cylinder 1
6d, 16e, and 16f may be communicated with the inner first chamber 20a, and it goes without saying that the structure may be such that the suction chamber 43 and the outer second chamber 19a are communicated from the beginning. do not have.

As described above in detail in the present invention, at least four or more cylinders 16a, 16b, 16c, 16
In the reciprocating compressor having the cylinders 16a to 16f, a suction chamber 43 formed around the crank bearing 11 of the frame 10 forming the cylinders 16a to 16f is separated by a partition wall 27 concentric with the bearing 11.
divided into a first chamber 20a and a second chamber 19a,
At least two or more suitable cylinders 16a, 16b, 16c among the cylinders 16a to 16f are communicated with the first chamber 20a, and the remaining at least two or more cylinders 16d, 16e, 16f are communicated with the second chamber 19a. On the other hand, since the partition wall 27 is provided with one on-off valve 29 in the radial direction for opening and closing the first chamber 20a and the second chamber 19a, the cylinder 16a
Capacity can be controlled with only one on-off valve 29 regardless of the number of ~16f installed, making the frame 10 and piping structure more compact, and reducing the need for cleaning and maintenance inspection of this on-off valve 29. It can be attached and detached more easily than in the radial direction, and the opening/closing valve 2
9 are provided in the radial direction and the frame 10 can be integrally molded, the centering and positioning between the shaft fitting portion of the crank bearing 11 and the cylinders 16a to 16f are easier than when they are formed in separate frames. The crankshaft 14 and the pistons 17a to 17f can be easily and accurately assembled into the frame 10, and can be processed easily and with high precision without the need for alignment.
0 and cylinder 30. Frame 10 and lid 32. Frame 10
It is possible to easily insert gaskets into places such as the lid member 21 where there is a possibility of gas leakage, thereby achieving remarkable effects such as being able to reliably prevent gas leakage.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic diagram showing an embodiment of the present invention;
FIG. 2 is an enlarged sectional view of the main part of FIG. 1, and FIG. 3 is a schematic diagram taken along the line - - in FIG. 10... Frame, 11... Crank bearing, 16a-1
6f...Cylinder, 19a...Second chamber, 20a...First
Chamber, 27...Partition wall, 29...Opening/closing valve, 43...Suction chamber.

Claims (1)

[Claims] 1. In a reciprocating compressor having at least four or more cylinders, a suction chamber formed around a crank bearing of a frame forming the cylinder,
It is divided into a first chamber and a second chamber by a partition wall concentric with the bearing, and at least two or more of the cylinders are placed in the first chamber, and at least two or more of the remaining cylinders are placed in the first chamber. A reciprocating compressor characterized in that a single opening/closing valve for opening and closing the first chamber and the second chamber is provided in a radial direction on a partition wall while communicating with the second chamber.