JPH10252653A - Sealed motor-driven compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly melt a welding part over the whole circumference even when apparatus bodies warp by joining a suction muffler composed of a synthetic resin apparatus body divided into plural parts by vibrating welding. SOLUTION: First of all, a first apparatus body 10 and a second apparatus body 11 are mutually pressurized by a stand 16' and a plate 16. Therefore, a flange 12 is pressed to the plate 16 from the direction perpendicular to contact planes, and since the apparatus body 10 and the apparatus body 11 are elastically deformed even when the contact planes 13 and 15 warp, the whole circumference of a welding surface is put in a contact condition. Afterwards, a certain constant vibration is imparted in parallel to the contact planes, and the contact planes 13 and 15 melt by frictional heating of the mutual contact planes, and a welding part is solidified and fixed by stopping its vibration, and the first apparatus body 10 and the second apparatus body 11 are integrally welded together. Welding time becomes almost constant even in either place by such a process, and since the welding surface is almost uniformly contacted over the whole circumference, excellent airtightness and welding strength can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hermetic electric compressor used for an electric refrigerator, an air conditioner and the like.

[0002]

2. Description of the Related Art In recent years, HFC-based and HC-based refrigerants that do not contain chlorine have been used as refrigerants for refrigeration cycles in order to prevent ozone layer destruction. It is already known that a compressor having a high energy efficiency is required, and a suction muffler made of a synthetic resin having a low thermal conductivity is suitable.

Conventionally, hermetic electric compressors have been disclosed in Japanese Patent Publication No. 3-45.
One described in Japanese Patent Publication No. 212 is known.

FIG. 8 shows the structure of a conventional hermetic electric compressor, in which 1 is a closed container, 2 is a compression element, 3 is an electric element, and the compression element 2 and the electric element 3 are elastically supported by the closed container 1. Have been. 4 is a cylinder, 5 is a piston reciprocating in the cylinder 4, 6 is a valve plate attached so as to close the opening of the cylinder 4, and 7 is a cylinder head. Reference numeral 8 denotes a suction muffler in which two synthetic resin bodies are joined by ultrasonic welding, and is attached to the cylinder head 7. Reference numeral 9 denotes a suction pipe for guiding the refrigerant gas into the closed container 1.

In the hermetic electric compressor constructed as described above, the refrigerant gas flowing from the low pressure side of the refrigerant cycle is guided into the closed vessel 1 through the suction pipe 9 and then into the cylinder 4 via the suction muffler 8. After being guided, it is compressed by the piston 5.

[0006]

However, the suction muffler made of synthetic resin tends to warp after molding due to uneven injection pressure and mold temperature during injection molding. Therefore, when welding is performed, a contact portion and a non-contact portion are generated due to warpage of the containers. Then, the contacted part melts first and gradually melts and welds to the entire circumference including the non-contact part.However, at the place where it first contacts and where it finally melts, the welding time differs due to the difference in the contact time. Occurs. That is, the manner of fusion of the contact portions becomes non-uniform due to the time difference. As a result, the non-contact portions of the respective bodies are not sufficiently fused in a short time portion, and a non-contact portion is generated. As a result, a gap is formed in a part of the joint, and a large amount of oil enters the suction muffler from the gap, causing valve damage due to the oil compression and the oil circulating in the external refrigeration system circuit and stagnating on the evaporator side. This causes poor cooling. Further, there is a problem that the joining strength of welding is insufficient and the suction muffler comes off during operation, and abnormal noise is generated.

On the other hand, in order to increase the strength and airtightness in order to cope with this problem, there is a means for increasing the pressing force or lengthening the welding time. In this case, the portion where the contact time is long melts intensively. The portion that has melted and protruded becomes burrs, and if the burrs are lost during operation, there is also a problem that the movement of the piston is hindered by entering the cylinder, and the valve mechanism is clogged to cause poor compression.

An object of the present invention is to provide a suction muffler made of a synthetic resin, which is uniformly and securely joined over the entire circumference and has no burrs. is there.

[0009]

In order to solve the above-mentioned problems, in the present invention, a suction muffler composed of a plurality of divided synthetic resin bodies is joined by a vibration welding method.

As a result, even when the vessel is warped, the welding portion is uniformly melted over the entire circumference, and no gap is generated, so that a higher welding strength can be secured.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is the one in which the joint portion of the suction muffler is welded by vibration, and is pressurized before welding, and frictional heat is generated by vibration when the entire periphery of the welding surface is in contact. In order to dissolve the contact surface, there is an effect that there is almost no non-contact portion and almost no non-contact portion is generated.

The invention according to claims 2 and 3 of the present invention
Vibration welding is performed by press-contacting the protrusions and grooves in a state where the protrusions and the grooves are loosely fitted, and has an effect that even if burrs are generated, the resin that has melted out in the loosely fitted portions does not drop inside and outside the muffler.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.
This will be described with reference to FIG. The same parts as those in the conventional example are denoted by the same reference numerals, and detailed description will be omitted.

(Embodiment 1) FIG. 1 is a plan view of a hermetic electric compressor according to an embodiment of the present invention, and FIG.
1 is a closed container, 2 is a compression element, 3 is an electric element, and the compression element 2 and the electric element 3 are elastically supported by the closed container 1. 4
Is a cylinder, 5 is a piston reciprocating in the cylinder 4, 6 is a valve plate attached so as to close the opening of the cylinder 4, and 7 is a cylinder head.
Reference numeral 8 denotes a synthetic resin suction muffler in which two containers are joined by vibration welding to guide the refrigerant gas into the cylinder 4, and is attached to the cylinder 7. Reference numeral 9 denotes a suction pipe for guiding the refrigerant gas into the closed container 1.

FIG. 3 is an exploded view of the suction muffler according to the first embodiment of the present invention, and FIG. 4 is an enlarged sectional view of a portion A in FIG.
Reference numeral 0 denotes a first container constituting the suction muffler 8, and reference numeral 11 denotes a second container constituting the suction muffler 8, each of which is formed by injection molding of polybutylene terephthalate (hereinafter abbreviated as PBT). 12 is a flange provided on the first body 10, 13 is a welding surface provided on the first body 10,
Reference numeral 14 denotes a flange provided on the second container 12, and reference numeral 15 denotes a welding surface provided on the second container 12. Reference numeral 16 denotes a plate attached to the pressing device, and 16 'denotes a frame for fixing the second container 11.

In the above configuration, the first container 1
The 0 and the second body 11 are first pressed together by the gantry 16 ′ and the plate 16. Accordingly, the flange 12 is pressed against the plate 16 from a direction perpendicular to the joint surface, and
Even when there is a warp in the container 15, the container 10 and the container 11 are elastically deformed, so that the entire periphery of the welding surface is in contact. After that, a certain vibration is given parallel to the joint surface,
15 are melted due to frictional heat generated between the contact surfaces of each other, and the vibration is stopped, whereby the melted portion is solidified and fixed, and the first vessel 1 is melted.
0 and the second container 11 are integrally welded.

By the above-described process, the welding time is almost constant at any point and the welding surface is almost uniformly contacted over the entire circumference, so that good airtightness and welding strength can be secured.

At this time, the vibration direction is generally one-way vibration parallel to the joint surface, but there is a method called orbital vibration welding that vibrates this in a substantially elliptical shape. Since a large trajectory is obtained and the joining surface can be reduced as a result, there is an effect that the appearance of the body of the suction muffler can be reduced.

(Embodiment 2) FIG. 5 is an exploded view of a suction muffler of a hermetic electric compressor according to Embodiment 2 of the present invention shown in claims 2 and 3, and FIG. 6 is an enlarged sectional view of a portion B in FIG. It is. FIG. 7 is an enlarged view of a main part showing a state after welding of FIG.

19 is a flange provided on the first body 17,
Reference numeral 20 denotes a convex protrusion provided on the first body 17, 21 denotes an end face of the protrusion 20, 22 denotes a base surface of the protrusion 20, 23 denotes a flange provided on the second body 18, and 24 denotes a flange. 2 body 18
, 25 is a bottom surface of the groove 24, 26 is a tip surface of the groove 24, and the height of the projection 20 is formed larger than the depth of the groove 24. 18 are formed so as to face the entire periphery of the edge, and when they are fitted, they are loosely fitted in a gap larger than the amplitude of vibration welding. 27 is the space volume of the loose fitting portion formed by the projection 20 and the groove 24, 28 is the volume of the end of the projection 20 formed by the difference between the height of the projection 20 and the depth of the groove 24, The space volume 27 of the loose fitting portion is the volume 2 at the end.
8 is formed. 29 is a plate attached to the pressing device, 30 is a gantry for fixing the second container 18, and 31 is a resin burr melted after welding.

In the above-described configuration, the end face 21 and the bottom 25 are melted by frictional heat between the contact surfaces at the time of vibration welding, and the burr 31 of the melted resin forms the space volume 2 of the loose fitting portion.
The welding is completed when the root surface 22 and the distal end surface 26 become substantially zero while staying within the area 7. Burr 3 melted at this time
The volume of 1 corresponds to the volume 27 of the end portion and is smaller than the space volume 28 of the loose fitting portion. Therefore, all the melted burrs 31 are contained in the space volume 28 of the loose fitting portion, and the suction muffler does not drop inside or outside. .

[0022]

As described above, according to the present invention, since the joint surfaces are uniformly welded, there is obtained an advantageous effect that no gap is generated and airtightness and welding strength can be ensured.

Further, according to the present invention, the protrusions and grooves of the suction muffler opposed to each other are loosely fitted so as to fit the melted resin into the loose fitting portion. An advantageous effect of not appearing is obtained.

[Brief description of the drawings]

FIG. 1 is an internal plan view of a hermetic electric compressor according to Embodiments 1 and 2 of the present invention.

FIG. 2 is an internal side view of the hermetic electric compressor according to Embodiments 1 and 2 of the present invention.

FIG. 3 is an exploded side view of the suction muffler according to the first embodiment of the present invention.

FIG. 4 is an enlarged sectional view of a portion A in FIG. 3;

FIG. 5 is an exploded side view of the suction muffler according to the second embodiment of the present invention.

FIG. 6 is an enlarged sectional view of a portion B in FIG. 5;

7 is an enlarged view of a main part after welding in FIG. 6;

FIG. 8 is an internal plan view of a conventional hermetic electric compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed container 2 Compression element 3 Electric element 8 Suction muffler 20 Projection part 24 Groove part 27 Space capacity of a loose fitting part 28 Volume of end part

Claims (3)

[Claims] 1. A compression element elastically supported in a closed container and an electric element for driving the compression element, wherein the compression element is provided with a suction muffler, and the suction muffler is divided into a plurality of parts. A hermetic compressor characterized by being formed of a resin container and formed by joining their containers by vibration welding. 2. A protruding projection is provided on a joint surface of an edge portion of at least one of the opposed bodies so as to face the projection portion on a joint surface of an edge portion of the other body. 2. The hermetic compressor according to claim 1, further comprising: a suction muffler formed by forming a concave groove portion, press-contacting the protrusion portion and the groove portion while allowing them to play, and joining them by vibration welding. . 3. The gap between the projection and the groove in the width direction is set to be equal to or greater than the vibration of vibration welding, and the height of the projection is larger than the depth of the groove, and the space volume of the gap formed in the width direction is reduced. 3. The hermetic compressor according to claim 2, wherein the volume is equal to or greater than the volume of the protrusion that melts when the end surfaces of the two bodies come into contact with each other.