JPH0227185A - Scroll compressor - Google Patents

Abstract

PURPOSE:To enable the absorption of the thermal stress and prevent breakage accident by providing a pipeline which consists of a vertical pipe and a flexible pipe branched from the vertical pipe, from the fixed part of a sealed container to its internal part. CONSTITUTION:When the time of the operation of a compressor, the discharging pressure an the inlet pressure is led into a valve seat space 25 through a pipeline 27. The heat actuates mutually to the pipeline 27. When such a heat actuates, a straight pipe 27b extending straight in the vertical direction is extended longer than a sealed container 11 by the difference of the thermal expansion coefficient. The straight pipe 27n adds the thermal stress in the lower direction to a U shaped pipe 27a. By this thermal stress, the U shaped pipe 27a is bend and pressed down to the lower so as to absorb the thermal stress and prevent the actuating of the thermal stress on the straight pipe 27b of the pipeline 27.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a scroll compressor that controls the volume of fluid, and particularly relates to an improvement in its piping system.

[Conventional technology]

FIG. 3 is a vertical sectional view of a conventional scroll compressor disclosed in, for example, Japanese Patent Laid-Open No. 60-206989. In the figure, 1 is a fixed scroll provided with a spiral protrusion 1b on the lower surface of the plywood part 1a, and 2 is an oscillating scroll provided with a spiral protrusion 2b on the upper surface of the base plate part 2a, below the center of the plywood part 2a. A swing shaft portion 2C protrudes from the top. Both spiral protrusions 1b.

2b are combined and compress the fluid towards the center of both spirals. Reference numeral 3 designates an inlet port formed on the outer periphery between the fixed and oscillating scrolls 1.2, and 4 a discharge port provided at the center of the plywood portion 1a of the fixed scroll 1. Reference numeral 5 denotes a compression chamber which is a space formed between the spiral protrusions 1b and 2b, and 6 is a main shaft, in which an eccentric hole 6b is provided in a large diameter portion 6a at the upper end. Reference numeral 7 denotes a swing bearing that is fitted into the eccentric hole 6b and supports the swing shaft portion 2C in the radial direction. 8 and 9 are the rotor and stator of the motor that drives the main shaft 6; 10 is an Oldham joint that restricts the oscillating scroll 2 to rotate in conjunction with the revolution without rotating when the main shaft 6 is driven; 11 is the scroll mechanism and the motor. It is an airtight container that houses the mechanism, and a bracket 11a is fixedly installed, and a bolt 1 is attached to this bracket lla.
The fixed scroll 1 is fixed by 1b. 12 is a suction pipe that is fixedly installed in the closed container 11 and communicates with the suction port 3 through the inside of the closed container 11. 13 is a discharge pipe that is fixed to the center of the fixed scroll 1, and is connected to the discharge port 4. The compressed gas from 4 is sent out of the closed container 11.

Next, the operation will be explained. When the rotor 8 rotates, the main shaft 6 rotates, and the oscillating scroll 2 rotates through the Oldham joint 10 while being prevented from rotating. As a result, the spiral protrusions 1b, 2b are passed from the suction pipe 12 to the suction port 3.
Suction gas is taken into the compression chamber 5 between the two, gradually compressed toward the center, and the compressed gas is discharged from the discharge port 4 into the discharge pipe 13.

The above-mentioned conventional scroll compressor is applied to an air conditioner and when used as an outdoor unit, the outdoor unit 1
In so-called multi-air conditioners, in which multiple indoor units are installed per unit, the capacity control of the outdoor unit, that is, the compressor, cannot follow changes in the load on the indoor unit due to changes in the number of operating indoor units, etc. There wasn't. In particular, when the load on the indoor unit side is low, the scroll compressor repeats numbering due to the operation of the thermostat, etc., and a large load is intermittently applied to the drive source such as the motor.

In addition, in an air conditioner, the suction pressure and discharge pressure change due to changes in indoor and outdoor altitudes both during cooling and heating, and as a result, the pressure ratio between the suction pressure and the discharge pressure fluctuates. The optimum pressure ratio of the compressor is set at the time of design, and maximum efficiency can be obtained when operating at this pressure ratio.If the pressure ratio fluctuates and deviates from the optimum pressure ratio as mentioned above, the compression power will decrease. Losses were incurred and efficiency decreased.

In order to solve the above problems, patent application No. 612834 was filed.
There is a scroll compressor previously proposed in No. 06. The scroll compressor of B is equipped with a mechanism for discharging the fluid in the compression chamber to the outside of the compression chamber on the base plate of the fixed scroll, and this mechanism is opened and closed by a bypass valve, and the bypass valve is driven by the suction pressure of the compressor and This is done by switching the discharge pressure, and the capacity is controlled by a bypass mechanism. In addition, a straight pipe connected to this bypass mechanism and for sending the fluid in the compression chamber to the outside of the closed container is fixed to the cover fixed to the base plate of the fixed gas tube and fixed to the closed container and installed vertically. There is.

In addition to this, similar piping is disclosed, for example, in Japanese Patent Application Laid-Open No. 61-87988. According to this document, piping that connects the outside of the closed container of the compressor and a pair of fluid bypass holes is shown, but there is no specific explanation about the shape of the piping. Also shown is the piping between a cover screwed onto the fixed scroll base plate and a straight pipe fixed to the cover, fixed to the closed container, and led out of the closed container.

However, since the various types of piping described above are made of steel pipes and the closed container is made of steel, there is a difference in the coefficient of thermal expansion between the two.

[Problem to be solved by the invention]

Conventional scroll compressors are constructed as described above, and due to the difference in thermal expansion coefficients mentioned above, thermal stress is generated in the steel pipes due to temperature rise during scroll compressor operation, and thermal stress is generated in the steel pipes due to repeated starting and stopping of the compressor. There were problems such as thermal stress occurring cyclically due to cyclical changes in temperature and causing the steel pipe to break.

This invention was made in order to solve the above-mentioned problems, and the shape of the piping that communicates between the fluid bypass hole and the outside of the sealed container is designed to absorb thermal stress caused by the difference in thermal expansion between the piping and the sealed container. The purpose is to obtain a highly reliable scroll compressor that prevents breakage accidents.

[Means for Solving the Problems] A scroll compressor according to the present invention includes:
It is equipped with piping consisting of a vertical pipe section that mainly extends vertically from the fixed part of the closed container into the inside thereof, and a flexible pipe section that branches from the vertical back section and is connected to a plurality of fluid bypass holes. be.

[For production]

In the scroll compressor of this invention, when the capacity is not controlled, the discharge pressure is guided through the piping, but since the temperature of the fluid having this discharge pressure is high, when the heat of this fluid acts, the vertical pipe part and the closed container are Due to the difference in thermal expansion in the longitudinal direction, the vertical tube section stretches more, applying vertical thermal stress to the flexible tube section, but the flexible tube section bends and absorbs this thermal stress. No large thermal stress is applied to the pipe section, preventing pipe breakage.

〔Example〕

Hereinafter, one embodiment of the invention of B will be described with reference to the drawings. 1st
The figure shows a longitudinal sectional view of a scroll compressor according to an embodiment of the present invention, and in the figure, reference numerals 1 to 12. la, 2a
~2c, 6a, 6b, lla.

Reference numeral 11b indicates a component that is the same as or equivalent to the component of the conventional example shown in FIG. 3, and its explanation will be omitted. Reference numeral 14 denotes an annular projection provided at the center of the plywood portion 1a of the fixed scroll 1 so as to surround the discharge port 4; 15 a discharge outlet fixed to the closed container 11 and fitted with the annular projection 14 to form a discharge chamber 16; It is a room cover. 17 is a discharge pipe connected to the discharge chamber cover 15 and drawn out of the closed container 11; 18 is an annular projection 14;
A sealing material placed around the outer periphery of the discharge chamber cover 15 seals the discharge chamber 16 to keep the discharge chamber 16 airtight.

Reference numeral 19 indicates a pair of left and right fluid bypass holes provided in the plywood portion 1a of the fixed scroll 1 and having an opening on one side in the compression chamber 5 before communicating with the discharge port 4. Reference numeral 20 indicates a ring-shaped groove 20a surrounding the fluid bypass hole 19. A ring-shaped groove 20 around the upper opening of the fluid bypass hole 19 is provided in the plate portion 1a.
It is a valve seat provided on the inner and outer periphery of a. Reference numeral 21 designates a discharge hole provided in the plywood portion 1a so as to have an opening on the side surface of the plywood portion 1a and communicate with the ring-shaped groove 20a. 22 is a disk-shaped bypass valve located on the ring-shaped groove 20a, and 23 is a cover that covers the upper part of the ring-shaped groove 20a and the bypass valve 22. 24 is a spring inserted into the ring-shaped groove 20a and holds the bypass valve 22; 25 is a valve seat space formed by the valve seat 20 and the cover 23; and 26 is a communication hole provided in the valve seat space 25 of the cover 23. be. 27 is a pipe made of copper, for example, which guides suction pressure and discharge pressure by switching a three-way solenoid valve (not shown), and is connected to the communication hole 26 of the cover 23 and the closed container 11.
It is fixed to a piping hole (not shown) by brazing.

Reference numeral 28 denotes an annular groove provided on the outer edge of the lower end of the cover 23, and an O-ring 29 fitted in the groove 28 seals between the cover 23 and the plywood portion 1a of the fixed scroll 1. 3
0 is a bolt that cantileverly fixes the cover 23 to the base plate portion 1a. A pair of each of the components 19 to 26, 20a, and 28 to 3o are provided.

FIG. 2 is a perspective view of the piping 27, etc., and in the same figure, the piping 27 is arranged horizontally and has a flexible U-shaped U-shaped tube section 27a, and is fixed to the central part thereof by brazing. A straight pipe part 27b is arranged vertically so as to be drawn out of the sealed container 11, and a communication hole 26 of the cover 23 is connected to both ends of the U-shaped pipe part 27a by brazing.

As described above, the straight tube portion 27b branches approximately at right angles to the surface 27c formed by the U-shaped tube portion 27a.

Next, the operation will be explained. When the compressor is operated at maximum capacity without capacity control, a three-way solenoid valve (not shown) is switched to guide discharge pressure to the pipe 27. As a result, the valve seat space 25
The pressure becomes the discharge pressure, and the discharge pressure acts on the bypass valve 22, so that the bypass valve 22 is pushed down against the spring force of the spring 24 and comes into close contact with the valve seat 20. As a result, the fluid bypass hole 19 and the discharge hole 21 are closed, so that the fluid in the compression chamber 5 flows from the discharge port 4 to the discharge chamber 16. It is discharged to the outside of the compressor through the discharge pipe 17.

When the compressor is operated by capacity control, suction pressure is introduced into the pipe 27 by switching a three-way solenoid valve (not shown).

As a result, the pressure in the valve seat space 25 becomes the suction pressure. Since the fluid bypass hole 19 is provided in the middle of the compression process of the compression chamber 5, the pressure in the compression chamber 5 communicating with the fluid bypass hole 19 is higher than the suction pressure. Therefore, the bypass valve 22 is pushed upward by the spring force of the spring 24 and is regulated by the cover 23, and the fluid bypass hole 19 and the discharge hole 21 communicate with each other, so that a part of the fluid in the compression chamber 5 is transferred to the fluid bypass hole. 19, it is discharged to the outside of the fixed scroll 1 which communicates with the suction space through the discharge hole 21, and the compression capacity in the compression chamber 5 is controlled.

As described above, when the compressor is in operation, the discharge pressure and the suction pressure are guided to the valve seat space 25 through the pipe 27. The temperature of the fluid having the above discharge pressure is high, and the temperature of the fluid having the above suction pressure is low, and these temperatures act on the pipe 27, and heat acts on the pipe 27 alternately as the compressor starts and stops. do.

When such heat is applied, the straight pipe portion 27b extending straight in the vertical direction extends longer than the closed container 11 due to the difference in thermal expansion coefficient due to the difference in the materials of the closed container 11 and the pipe 27. The position of the fixed scroll 1, the cover 23, and the vertical position of the U-shaped tube portion 27a depend on the thermal expansion of the hermetic container 11, so the straight tube portion 27b moves downward relative to the U-shaped tube portion 27a. Apply thermal stress. Due to this thermal stress, the U-shaped tube portion 27a is bent and pushed downward to absorb the thermal stress, thereby preventing large thermal stress from acting on the straight tube portion 27b of the pipe 27.

In addition to B, the piping includes a flexible pipe section that extends mainly vertically from the fixed part of the sealed container into the interior of the container, and which branches off and connects to the fluid bypass hole. On the other hand, any type of piping may be used as long as it has a flexible structure.

〔Effect of the invention〕

As described above, according to the present invention, there is a vertical pipe section that mainly extends vertically from the fixed part of the sealed container into the inside thereof, and a flexible pipe that branches from this vertical pipe section and is connected to a plurality of fluid bypass holes. Since the flexible pipe part bends and absorbs the thermal stress of the @1 pipe part, there is no chance of pipe breakage due to repeated thermal effects, and reliability is improved. It has the effect of getting expensive things.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a scroll compressor according to an embodiment of the present invention, FIG. 2 is a detailed perspective view of the piping shown in FIG. 1, and FIG. 3 is a longitudinal sectional view of a conventional scroll compressor. It is. In the figure, 1. Fixed scroll, la, 2a. Base plate part, Ib.
, 2b... spiral protrusion, 2... rocking scroll, 3...
Suction port, 4...Discharge port, 5...Compression chamber, 6. Main shaft,
8. Rotor, 9. Stator, 11. Sealed container, 11
b...Bolt, 19...Fluid bypass hole, 22 Bypass valve, 27...Piping, 27a...U-shaped pipe section, 27
b... Straight pipe section. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] A fixed scroll with a spiral protrusion on the lower surface of the base plate and a discharge port in the center, and a rocking scroll that is combined with the fixed scroll and has a spiral protrusion on the upper surface of the base plate to form a compression chamber. a scroll, a driving means for driving the oscillating scroll, a closed container accommodating the fixed scroll, the oscillating scroll and the driving means, and a fluid provided in the base plate of the fixed scroll and communicating with the discharge port. In a scroll compressor equipped with a plurality of fluid bypass holes for leading out fluid from the compression chamber, a vertical pipe section that extends mainly vertically into the closed container from a fixed part to the closed container, and a vertical pipe section that branches from the vertical pipe section. 1. A scroll compressor characterized in that a piping comprising a flexible pipe section connected to the fluid bypass hole is provided.