JP2006161703A - Terminal cover for compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low noise and reliable terminal cover in relation to a compressor. <P>SOLUTION: A terminal 103 attached to a hermetic vessel 101, and the terminal cover 115 covering electric parts connected to the terminal 103 and at least a part of which is formed out of resin foamed material are provided. Acoustic energy is absorbed by friction of gas in foams formed in the resin foamed material and resin material around the foam to attenuate noise from a flat surface part 102 of the hermetic vessel 101. And operation of a thermal sensitive type protection device 112 is ensured by thermal insulation effect. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement of a terminal cover of a compressor used in a refrigerator / freezer such as a refrigerator.

  In recent years, electric compressors used in refrigeration systems and the like are strongly required to have high reliability in addition to low noise during operation.

  As a terminal cover of a conventional electric compressor with a built-in motor, the terminal portion is covered with a sealed container constituting the compressor body, and is formed of a solid resin having flame retardancy and insulation, for example, modified PPE, and is thermally sensitive. There is one that holds the heat-sensitive surface of the protection device of the mold in a sealed container. (For example, refer to Patent Document 1).

  Hereinafter, a terminal cover used in the above-described conventional compressor will be described with reference to the drawings.

  FIG. 5 is an exploded perspective view of a terminal cover of a conventional compressor.

  In FIG. 5, a terminal 3 having a plurality of terminals for connecting the inside and outside of the sealed container is attached to the side surface of the flat portion 2 of the sealed container 1 containing a motor (not shown) and a compression element (not shown). A terminal box 4 whose front and lower surfaces are open is attached.

  Inside the terminal box 4, a cluster housing 11 in which a cluster terminal (not shown) inserted and coupled to the terminal 3 is incorporated, and a heat sensitive surface (not shown) of the heat sensitive protection device 15 is fixed to the flat portion 2. Holding portions 16 that are stored and held at intervals are arranged, and are covered with a terminal cover 18 formed of a solid resin.

  The terminal cover 18 is fixedly supported by the terminal box 4 by engaging both ends of the cover holding spring 20 with the engagement holes 22 of the terminal box 4.

Further, when some abnormality occurs in the motor of the compressor and the compressor becomes an abnormally high temperature or a large current flows, the sensitive surface temperature of the heat-sensitive protection device 15 increases with the temperature rise, and the heat-sensitive type. The protective device 15 is activated to protect the compressor.
JP 2002-373734 A

  However, in the above-described conventional configuration, the flat portion 2 for attaching the terminal 3 to the sealed container 1 constituting the compressor body is provided, and the flat portion 2 constituted by this plane is weak in rigidity. Although vibration occurs and noise is generated with the operation of the main body, since the terminal cover 18 is made of a solid resin, the sound insulation is low, and the noise generated from the flat portion 2 cannot be sufficiently reduced.

  Further, although the heat-sensitive protective device 15 is attached to the electrical component, even when the temperature of the sealed container rises, heat is radiated from the terminal cover 18, and the temperature rise in the terminal cover 18 increases the temperature of the sealed container 1. As a result, the operation of the heat-sensitive protection device 15 is delayed, and the compressor main body may not be sufficiently protected.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a compressor terminal cover with low noise and high reliability.

  In order to solve the above-described conventional problems, a terminal cover of a compressor according to the present invention covers a terminal attached to a hermetic container constituting a compressor body, and electrical components connected to the terminal, and at least a part thereof. Is formed of a resin foam material, and has the effect that acoustic energy is absorbed by the friction between the gas in the bubbles formed in the resin foam material and the resin material around the bubbles and the sound transmission loss is increased.

  The compressor of this invention can attenuate the noise from the plane part of the airtight container which comprises a compressor main body.

  The invention according to claim 1 covers a terminal attached to a sealed container constituting the compressor body and an electrical component connected to the terminal, and at least a part thereof is formed of a resin foam material. The acoustic energy is absorbed by the friction between the gas in the bubbles formed in the resin foam material and the resin material around the bubbles and the sound transmission loss is increased, so that the noise from the flat part of the sealed container constituting the compressor body is reduced. It is possible to provide a terminal cover for a compressor that can be reduced and has low noise.

  According to a second aspect of the present invention, in the first aspect of the invention, the electrical component includes a heat-sensitive protective device. Compared to the higher heat insulation performance and reduced heat dissipation from the terminal cover, the temperature rise in the terminal cover quickly follows the temperature rise in the compressor body, enabling high-accuracy temperature protection and higher reliability. Compressor terminal cover can be provided.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the bubble diameter of the resin foam material is 50 μm or less, and the bubble diameter is reduced by reducing the bubble diameter formed in the resin foam material. Since the number increases and the sound transmission loss and the heat insulation effect increase, it is possible to provide a highly reliable compressor terminal cover with lower noise.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the foaming resin material has a foaming ratio of 1.2 times or more, and further has acoustic transmission loss and heat insulation. Since the effect is enhanced, in addition to the effect described in claims 1 to 3, it is possible to provide a compressor terminal cover with further low noise and high reliability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
1 is an exploded perspective view of a terminal cover of a compressor according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view of the terminal cover of the compressor according to the same embodiment, and FIG. 3 is a view of the compressor according to the same embodiment. FIG. 4 is an enlarged cross-sectional view of the terminal cover, and FIG. 4 is a schematic configuration diagram of the supercritical foam molding machine in the same embodiment.

  1 to 4, a terminal 103 having a plurality of terminals communicating between the inside and outside of the sealed container is provided on the side surface of the flat portion 102 of the sealed container 101 containing a motor (not shown) and a compression element (not shown). A relay 106 and a heat-sensitive protection device 112 are attached to the terminal 103 as electrical components wired (not shown).

  The terminal cover 115 is locked and fixed to the terminal box 107 by engaging a pair of protrusions 117 provided inside with the engagement hole 120 of the terminal box 107.

  The terminal cover 115 is formed by supercritical foam molding (details will be described later), and fine bubbles 250 having a bubble diameter of 1 to 50 μm are present on all wall surfaces.

Here, since the air bubbles 250 formed by the supercritical foam molding process are formed with a high density of about 10 ⁹ to 10 ¹⁵ cells / cm ^{3, the} heat insulation performance can be improved by about 20% or more compared to the solid material. .

  In addition, as shown in FIG. 4, the supercritical foam molding machine 259 used for molding the terminal cover 115 of the present embodiment includes a raw material insertion unit 260, a supercritical gas generation unit 264, a dissolution injection unit 261, , A mold part 262 and a control part 263 for controlling the drive and cooling temperature of the mold part, and without using a foaming agent such as an azo compound or chlorofluorocarbon, which is an environmentally hazardous substance. Because it uses an inert gas, etc., it can be molded easily into the environment.

  Next, a foaming resin molding process using the supercritical foam molding machine 259 will be described.

  First, raw material pellets of polybutylene terephthalate are charged into the raw material insertion portion 260. The charged raw material pellets are melted at a temperature of about 250 ° C. or more in the melt injection unit 261. On the other hand, the carbon dioxide or nitrogen of the physical foaming agent that has become supercritical in the supercritical gas generation unit 264 is injected into the dissolution injection unit 261 and mixed with the resin raw material as a high-pressure liquid.

  Thereafter, a supercritical foaming agent is injected into the mold part 262 together with the raw material melted by the screw built in the melt injection part 261. Then, bubbles 250 are formed by gasifying the supercritical foaming agent due to a rapid volume change or temperature change that occurs during injection into the mold part 262.

  At this time, the control unit 263 controls the temperature and pressure at the time of molding by adjusting the injection amount and injection temperature of the raw material and the foaming agent and the temperature of the mold part 262, thereby controlling the cell density and cell diameter of the foamed resin. Can be adjusted.

  Further, during this molding, pressure is applied from the inside of the resin toward the mold due to the molding pressure of the bubbles, so that the resin raw material in the vicinity of the mold is pressed toward the mold to form a skin layer in which the bubbles 250 are not formed.

  The operation of the terminal cover of the compressor configured as described above will be described below.

  Due to the operation of the compressor, noise is radiated from the flat surface portion 102 of the hermetic container 101 constituting the compressor body having relatively low rigidity. At this time, the resin foam material of the terminal cover 115 itself absorbs the vibration energy due to the vibration loss of the material caused by the vibration of the noise energy and the friction between the gas in the bubble 250 and the material around the bubble 250. The noise radiated from the flat portion 102 of the sealed container 101 is attenuated by a synergistic effect with the improvement of the sound transmission loss.

  In the present embodiment, supercritical carbon dioxide or nitrogen dissolved in a molten resin material is gasified according to changes in temperature and pressure to form extremely fine bubbles 250 having a diameter of 1 to 50 μm. Furthermore, since the expansion ratio can be increased to 1.2 times or more, fine bubbles 250 are formed on all the side walls without changing the basic design dimensions of the terminal cover 115.

  As a result, the sound transmission loss due to the absorption of the vibration energy by the friction between the gas in the bubble 250 and the material around the bubble 250 is further improved, and is radiated from the flat portion 102 of the sealed container 101, particularly in the audible range. The transmitted sound of high frequency components is greatly attenuated.

  On the other hand, since fine bubbles 250 are formed on all the side walls of the terminal cover 115, heat radiation from the terminal cover 115 is reduced, and the temperature inside the terminal cover 115 increases the temperature of the sealed container 101 constituting the compressor body. It becomes easy to follow. As a result, if some abnormality occurs in the compressor body and the temperature rises, the temperature inside the terminal cover 115 rises rapidly as the temperature of the flat portion 102 rises, so the sensitive surface temperature of the heat-sensitive protective device 112 also rises quickly. Since the heat-sensitive protection device 112 operates quickly, the compressor can be protected more reliably and high reliability can be obtained.

  In addition, since a skin layer in which bubbles 250 are not formed is formed on the surface of the terminal cover 115, even if the pair of protrusions 117 provided inside rub against the engagement hole 120 of the terminal box 107, it is durable. Sex is the same as innocent.

  Furthermore, since the fine closed cells 250 can be formed on all the wall surfaces of the terminal cover 115 by using the supercritical foam molding technique of the present embodiment, the mechanical strength of the material is hardly lowered, and the expansion ratio Since the amount of raw material used can be reduced by 20% or more by setting the ratio to 1.2 times or more, the cost can be reduced.

  As described above, since the terminal cover according to the present invention can reduce noise and increase the reliability of the compressor, it can also be applied to a refrigerator-freezer such as an air conditioner or a vending machine.

The disassembled perspective view of the terminal cover of the compressor in Embodiment 1 of this invention Sectional drawing of the terminal cover of the compressor in the same embodiment The expanded sectional view of the terminal cover of the compressor in the embodiment Schematic configuration diagram of a foam molding machine in the same embodiment An exploded perspective view of a terminal cover of a conventional compressor

Explanation of symbols

101 Airtight container 103 Terminal 112 Heat-sensitive protective device 115 Terminal cover

Claims (4)

The terminal cover of the compressor which covered the terminal attached to the airtight container which comprises a compressor main body, and the electrical component connected to the said terminal, and at least one part was formed with the resin foam material. The terminal cover of the compressor according to claim 1, wherein the electrical component includes a heat-sensitive protection device. The terminal cover of the compressor according to claim 1 or 2, wherein a bubble diameter of the resin foam material is 50 µm or less. The terminal cover of the compressor as described in any one of Claim 1 to 3 which made the foaming ratio of the resin foam material 1.2 times or more.

Images