JPH0643515Y2 - 2-cylinder rotary compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a two-cylinder rotary compressor, and more particularly to a two-cylinder rotary compressor configured to prevent reverse flow of refrigerant in a refrigeration cycle by reverse rotation when stopped. It is a thing.

[Prior Art] FIG. 4 and FIG. 5 show an example of a conventional two-cylinder rotary compressor according to the technology disclosed in Japanese Utility Model Laid-Open No. 59-111984.

6 and 7 show a conventional example of a reverse rotation preventing device for a rotary compressor disclosed in Japanese Utility Model Laid-Open No. 60-167185. The arrows indicate the flow of the refrigerant.

In the figure, 1 is a closed container, 2 is an electric element stored in the upper part of the closed container 1, 2 is stored in the lower part of the closed container 1,
The compression element 4 driven by the drive shaft 2a of the electric element 2 is a partition plate for the cylinders 5 and 6, and 5 and 6 are the cylinders arranged on the upper and lower sides of the partition plate 4, respectively. The open end of is closed by upper and lower bearings 16 and 17, which will be described later. 7, 8 are eccentric parts integrally formed with the drive shaft 2a of the electric element 2, 9 and 10 are integrally fitted and attached to these eccentric parts 7, 8 and housed in the upper cylinder 5 and the lower cylinder 6, respectively. It is a rolling piston. The springs 13 press the tips of the springs 11 and 12 onto the outer circumferences of the rolling pistons 9 and 10, and as the rolling pistons 9 and 10 rotate, the vane grooves 5 of the cylinders 5 and 5 are rotated.
By sliding in the cylinders a and 6a, the compression chambers 14 and 15 formed by the cylinders 5 and 6, the partition plate 4, the upper and lower bearings 16 and 17 and the rolling pistons 9 and 10 are connected to the high pressure chambers 14a and 15a and the low pressure chambers. It is a vane that divides into 14b and 15b. The eccentric portions 7 and 8 are formed with a phase difference of 180 degrees. 16 is an upper bearing of the drive shaft 2a, and 17 is a lower bearing of the same. Reference numeral 18 is a discharge pipe for connecting a refrigeration cycle (not shown), 19 is an accumulator provided adjacent to the closed container 1, 20 is a suction pipe for connecting the accumulator 19 and the refrigeration cycle, and 21 and 22 are the cylinders 5 and 6, respectively. accumulator
A suction connection pipe connecting 19; 23, a suction port; and 24, a discharge port.

Further, in FIG. 6 and FIG. 7, 25 is the suction connection pipe 21.
The check valve is provided with a valve seat 26, a valve body 27 that opens and closes the valve seat 26, a spring 28 that operates the valve body 27, and a stopper 29.

Next, the operation will be described.

When the drive shaft 2a is rotated by the electric element 2, the refrigerant of the refrigeration cycle enters the accumulator 19 through the suction pipe 20, passes through the suction connection pipes 21 and 22, and is alternately sucked into the cylinders 5 and 6. Then, the refrigerant compressed in each of the cylinders 5 and 6 is alternately discharged into the closed container 1, passes through the discharge pipe 18, and forms a refrigeration cycle.

In addition, in FIG. 6, FIG. 6 and FIG. 7, when the rotary compressor stops, the check valve 25 provided in the suction connecting pipe 21 for preventing the reverse flow of the refrigerant is shown in FIG. (B)
As shown in, the valve body 27 contacts the valve seat 26 to prevent the high pressure gas of the refrigerant from flowing backward from the suction connecting pipe 21 and preventing the reverse rotation.

[Problems to be Solved by the Invention] In a conventional rotary compressor, a normal rotation is made in a direction indicated by an arrow in FIG. 5 during normal operation, but when operation is stopped, a pressure difference occurs, so that the compressor passes through each gap of compression elements. The gas on the high-pressure side of the refrigeration cycle flows backward to the low-pressure side, and inside the compressor, the high-pressure gas in the closed container passes through the inside of the compression element and flows to the accumulator side, which sucks the drive shaft from the discharge port side. A force acts on the port side and the drive shaft rotates in the direction opposite to the arrow. In the case of a 1-cylinder compressor, if the reverse rotation is performed up to the crank angle 0 ° position (the position advanced 180 ° from the crank position in Fig. 5), the discharge port and the suction port communicate, so there is no force in the opposite direction to the drive shaft and there is no reverse rotation. It only takes a few seconds. However, in the case of a two-cylinder compressor, since the eccentric parts of the drive shaft have a phase difference of 180 ° with each other, even if one compression element comes to a position where discharge and suction communicate, the other compression element At the crank position shown in Fig. 5, a reverse force acts on the drive shaft, and in this way, a reverse force acts on the drive shaft alternately by both compression elements, so the reverse phenomenon occurs when the high pressure side and the low pressure side of the refrigeration cycle are balanced. Continue for a few minutes.

As a reverse rotation preventing device for a compressor, a device using a check valve has been devised, but when a check valve is attached, for example, the check valve disclosed in Japanese Utility Model Laid-Open No. 60-167185 is disclosed. In the above, there is a problem that the check valve causes a large fluid resistance during normal operation, and the pressure loss of the check valve during operation reduces the performance (efficiency) of the compressor.

Furthermore, when the pressure is cut off by the check valve, the pressure difference of the refrigerant remains in the refrigeration cycle, and when continuously restarted, it will be driven in the state of overload,
It is mechanically damaged or fails to start.

Therefore, the present invention was made in order to solve the conventional problems as described above, and prevents the reverse flow of the refrigeration cycle of the refrigerant due to the reverse rotation of the compressor immediately after the operation is stopped,
An object of the present invention is to obtain a two-cylinder rotary compressor that does not impair the function of the refrigeration cycle and that is easy to start in a light load state without mechanical damage at the time of restart for restarting the operation.

[Means for Solving the Problems] A two-cylinder rotary compressor according to the present invention comprises an electric element arranged in a closed container, two upper and lower compression elements driven by the electric element, and The suction connection pipe that directly guides the refrigerant compressed by one compression element from the accumulator to the one compression element, the suction connection pipe that guides the refrigerant from the accumulator to the other compression element, and the suction connection pipe are provided. And a check valve for preventing the reverse flow of the refrigerant.

[Operation] In the two-cylinder rotary compressor according to the present invention, when the refrigerant tries to flow back to the accumulator side due to the high and low pressure difference in the cylinder at the time of operation stop, the check valve provided in the suction connecting pipe is operated and the reverse flow Will stop. As a result, the refrigerant cannot flow backward, and the reverse rotation of the compression element can be braked. At the same time, the other suction connection pipe connects the accumulator and the compression element, and as a result, the internal pressure of the system in which the refrigerant circulates as the entire refrigeration cycle can be equalized in a short period of time, and the load of the compression element in the initial stage of start-up. To reduce.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of a two-cylinder rotary compressor according to an embodiment of the present invention. 2 (a) and 2 (b) are enlarged longitudinal sectional views showing the operating state of the check valve of the two-cylinder rotary compressor according to one embodiment of the present invention, and FIG. 2 (c) is the same. It is an expansion perspective view of the valve body of a check valve. The same reference numerals as those in FIGS. 4 and 5 of the conventional example show the same or corresponding portions as those of the conventional example.

In FIG. 1, 21 is a suction connecting pipe connecting the accumulator 19 and the upper cylinder in the closed container 1, and 22a and 22b are suction connecting pipes connecting the lower cylinder in the closed container 1 of the accumulator 19, which are reversed in the middle. It is configured at a right angle through a stop valve 25. That is, the check valve 25 is arranged at the intersection of the right angles.

In FIG. 2, the check valve 25 includes a valve seat 26, a valve body 27 that opens and closes the valve seat 26, a spring 28, and a frame body 30. The frame body 30 includes the valve seat 26, the valve body 27, and the spring. Accommodates 28. The valve body 27 has a shape formed by cutting a cylinder obliquely with respect to the central axis direction, and correspondingly, the valve seat 26 also has a shape obtained by cutting the cylinder obliquely with respect to the central axis. The arrow indicates the flow of the refrigerant.

Next, the operation will be described.

During operation, due to the rotation of the drive shaft, the refrigerant from the refrigeration cycle enters the accumulator 19 from the suction pipe 20, and the suction connection pipe
The gas is alternately sucked into each cylinder through 21, 22a, 22b and the check valve 25. In operation, the check valve 25 is shown in Fig. 2 (a).
As described above, the valve body 27 is pushed down against the spring 28 by the intake gas flow. In this embodiment, the valve body 27 is formed by cutting a cylinder obliquely with respect to the central axis thereof, and the suction connecting pipes 22a and 22b are straight pipes, which are configured to be at right angles, so that the suction pipe during operation is It is possible to suppress the pressure loss when the gas flows through the check valve.

Next, when the compressor stops, as shown in FIG. 2 (b), due to the pressure difference between the spring 28 of the check valve 25 and the valve body.
27 is immediately pressed against the valve seat 26 to prevent the reverse flow of the refrigerant and prevent the reverse rotation phenomenon at the time of stoppage that occurs in the two-cylinder rotary compressor.

That is, if the check valve 25 prevents backflow between the suction connection pipe 22a and the suction connection pipe 22b, when the operation is stopped,
The check valve 25 increases the pressure in the suction connection pipe 22b, prevents the rolling piston 10 from rotating in the reverse direction, and as a result, is in a braked state. At this time, the pressure of the rolling piston 9 in the other suction connecting pipe 21 is
And the pressure on the discharge pipe 18 side is made uniform through the entire refrigeration cycle including the accumulator 19. Therefore, the pressure difference between the two sides of the rolling pistons 9 and 10 is rapidly eliminated, reverse rotation can be prevented, and at the same time, the pressure of the entire refrigeration cycle can be made uniform. In addition, since the pressure of the entire refrigeration cycle can be made uniform, the starting current of the electric element 2 increases due to the overload of the compression element 3 at the time of restarting, and the cutout cannot be activated and the compression element 3 cannot start. And the drive shaft 2a of the electric element 2, the upper,
The lower bearings 16 and 17 will not be damaged.

In the above embodiment, the valve body 27 of the check valve 25 is formed by cutting the cylinder obliquely with respect to the central axis thereof. However, as shown in FIG. On the other hand, the shape may be formed by cutting into an arc shape.

That is, the valve body 27 of the check valve 25 when implementing the present invention is
Any valve element may be used as long as it is formed to be inclined so as to maintain a cross-sectional shape similar to the cross-sectional shape of the suction connection pipes 22a and 22b. In particular, in the structure formed as shown in FIG. 3, the fluid resistance during normal operation can be reduced.

[Advantages of the Invention] As described above, according to the present invention, the electric element arranged in the closed container, the two upper and lower compression elements driven by the electric element, and the one compression element. Direct the refrigerant compressed by the suction connection pipe from the accumulator to the one compression element, and the backflow of the refrigerant disposed in the suction connection pipe and the suction connection pipe from the accumulator to the other compression element. It is guided through a check valve that prevents it.

Therefore, when the refrigerant tries to flow back to the accumulator side due to the high and low pressure difference in the cylinder when the operation is stopped,
The check valve provided in the suction connecting pipe is activated to prevent the backflow. This brakes the refrigerant so that it does not flow backwards and the compression element and drive element do not reverse, and the other suction connection pipe connects the accumulator and the compression element to increase the internal pressure of the system in which the refrigerant circulates as a whole refrigeration cycle. It can be homogenized in a short period of time.

Therefore, immediately after the operation is stopped, the abnormal vibration due to the reverse rotation of the compressor is prevented, and the internal pressure of the refrigerant circulating in the refrigeration cycle is equalized in a short period of time, that is, the load of the compression element is lightened to perform the operation. At the time of restarting, it can be started easily without being mechanically damaged.

Further, in the two-cylinder rotary compressor according to claim 2 of the utility model registration, since the check valve for preventing the reverse flow of the refrigerant is arranged at the intersection of the suction connecting pipes at the right angle, the suction connecting pipes. It is possible to use a straight pipe, which is advantageous in terms of assembly and parts cost.

Further, in the two-cylinder rotary compressor according to claim 3 of the utility model registration, the valve body is formed so as to be inclined so as to maintain a cross-sectional shape close to the cross-sectional shape of the valve seat portion and the two suction connecting pipes, Since the spring for operating the valve body and the frame for accommodating the valve seat, the valve body, and the spring are formed, the check valve can have a structure with low pressure loss, and
Reverse rotation can be prevented when the compressor is stopped.

[Brief description of drawings]

FIG. 1 is a two-cylinder rotary compressor according to one embodiment of the present invention, and FIGS. 2 (a) and 2 (b) are longitudinal sectional views showing the operating state of the check valve of the present invention in an enlarged manner. FIG. 3C is an enlarged perspective view of the valve body of the check valve, and FIGS. 3A and 3B are a longitudinal sectional view and a perspective view showing the valve body of the check valve according to another embodiment of the present invention. , FIG. 4 is a vertical sectional view of a conventional two-cylinder rotary compressor, and FIG.
FIGS. 7 (a) and 7 (b) are a partially cutaway front view and a magnified cross-sectional view of an essential part showing a conventional reverse rotation prevention device for a compressor. In the figure: 1: Closed container 2: Electric element 2a: Drive shaft 5,6: Cylinder 9,10: Rolling piston 14,15: Compressor 19: Accumulator 20: Suction pipe 21,22: Suction connection pipe 26: Valve seat 27: Valve body 28: Spring In the drawings, the same reference numerals and symbols indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Katsuyuki Kawasaki 3-18-1, Oga, Shizuoka-shi, Shizuoka Mitsubishi Electric Corporation Shizuoka Works (56) References Kai 60-167185 (JP, U)

Claims (3)

[Scope of utility model registration request] 1. An electric element arranged in a closed container, and two compressions, an upper side and a lower side, which are driven by the electric element to suck and compress a refrigerant forming a refrigeration cycle and send it out of the closed container. An element, a refrigerant compressed by the one compression element, is directly led from an accumulator to the one compression element, and a suction connection pipe capable of flowing backward through a gap of the compression element, and the other compression element. The other suction connection pipe for guiding the refrigerant from the accumulator to the other compression element,
And a check valve that is provided only on the other suction connection pipe and that prevents the reverse flow of the refrigerant. 2. A utility model characterized in that a suction connecting pipe connecting the other compression element in the closed container and the accumulator is constructed such that two straight pipes are formed at a right angle through a check valve. The two-cylinder rotary compressor according to claim 1. 3. The check valve includes a valve seat portion, a valve body inclined to maintain a cross-sectional shape similar to the cross-sectional shape of the two suction connection pipes, a spring for operating the valve body, and the above-mentioned. Claim 1 for a utility model characterized in that it is configured as a frame for accommodating a valve seat, a valve body, and a spring.
A two-cylinder rotary compressor according to the item.