JPS61252878A - Ball joint piston device for enclosed type compressor - Google Patents

Abstract

PURPOSE:To enable the reduction of overall piston length and obtain a ball joint type piston device of sturdy construction and less expensive wherein an oil basin can be easily formed, by caulking a connection between the piston and the ball at a part other than the end of piston periphery. CONSTITUTION:An escape 13a as contacting a spherical surface and used as an oil basin is provided inside of the caulking position of piston spherical part 11. In this spherical part 11 is inserted a ball 6 and oil is sealed. And one part 5a other than the end of the periphery of a piston 5 is made to form a plurality of caulking connections a all around said piston 5 or exceeding three positions. The positional relation of the piston 5 and the ball 6 is such that a contact position between the piston spherical part 11 and the ball 6 is so taken as to keep an angle theta at 20 degrees or more between a line C connecting the center of gravity b of the ball to a part of the piston spherical part 11, and another line d in parallel with piston top and passing said center of gravity b.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a ball joint type piston device for a hermetic compressor that is incorporated into a hermetic compressor used in a refrigeration cycle or the like.

<Prior Art> In this type of conventionally used ball joint type piston device, the piston and the ball are connected by caulking at the rear end of the piston, as shown in FIG. In this case, in order to maintain the sealing performance between the piston and the cylinder, it is necessary to design the piston to be long in the longitudinal direction to some extent. Accordingly, the weight of the piston has increased, resulting in deterioration of vibration and noise characteristics.

In addition, when the piston spherical part and the ball are in contact,
Although there is no specific disclosure at present, if, for example, both the piston spherical part and the ball could be made into true spherical shapes and they were joined together by caulking, there would be no gap between the piston spherical part and the ball, which would result in a so-called solid state. This results in an unreliable structure that increases sliding resistance and makes it difficult to lubricate with oil.

Furthermore, in examples where an oil reservoir is provided at the tip of the piston spherical part (for example, Japanese Patent Publication No. 45-40204, Japanese Patent Application Laid-open No. 59-40064), the distance from the caulking part is long, and the distance between the piston and the ball is large. It is unsuitable for lubrication, which requires oil lubrication through extremely small gaps between the parts. Furthermore, in extreme cases, there may be situations where the oil stored at the tip of the piston is not lubricated, and the piston and balls may become locked due to the oil turning into sludge.

In addition, when integrally forming the ball, which is the drive means for the piston that slides in the cylinder, the connecting rod, and the ring that becomes the crankshaft side, if only the ball and ring are heat-treated and the connecting rod is left untreated, projection welding is possible. The welding strength is low, and it is difficult to obtain a perpendicularity (axis line) between the ring and the connecting rod.

<Problems to be Solved by the Invention> In view of the above-mentioned circumstances, the present invention aims to provide a ball joint type 1-type piston device that has a caulking means that allows easy formation of an oil-tight seal, is robust, and is inexpensive. This is what I did.

<Means for Solving the Problems> The present invention provides a piston device having a pole joint compression structure in which a piston and a connecting rod that slide in a cylinder incorporated in a hermetic compressor are arranged with a spherical joint.
The connection between the piston and the ball is made by caulking the entire circumference of the piston at a part other than the end of the outer periphery of the piston, or by caulking at three or more places, and this caulking connection between the piston and the ball is performed by caulking the piston and the ball at a part other than the end of the piston's outer circumference. The contact position (hitting position) is a line connecting the center of gravity of the ball and a part of the spherical surface of the piston,
It has a configuration in which the angle between the center of gravity of the ball and a line parallel to the piston top surface is 20' or more, and in this case, a spherical contact relief part for oil filling and strain relief is connected to the inside of the piston caulking part position. In addition, the ball, connecting rod, and ring are integrated by applying a prescribed heat treatment to all three parts, and then projection welding each connection position.

Due to the structure of the piston device as described above, the overall length of the same piston can be shortened, a gap is provided at the tip of the piston's spherical surface, the sliding load between the piston's spherical surface and the ball can be reduced, and the piston can be connected to the ball. The axis of the rod can be reliably aligned and it is sturdy.

<Example> Hereinafter, the present invention will be described in detail based on the drawings of the example.

Reference numeral 1 denotes a hermetic compressor which has a motor part 2 and a compression part 3 built into a hermetic case 1a, and a ball 6 supported by a slidable piston 5 in a cylinder 4 constituting the compression part 3 is , the connecting rod attached to this 7. A crankshaft 10 that rotates eccentrically is arranged at the end of the shaft 9 of the motor section 2 via a ring 8.
It is something that is connected to or connected to. In this case, the piston 5 is connected to the ball 6 by caulking the entire circumference of the piston at a portion 5a of the outer circumference of the piston 5 other than the end as shown in FIG.
Or, as shown in Fig. 4, three or more places are caulked together a, and in this case, the positional relationship of the ball 6 with respect to the piston 5 is the same as that of the ball seat as shown in Figs. 5 and 6. The angle between the contact position between the piston spherical surface 11 and the ball 6, the center of gravity of the ball, a line C connecting a part of the piston spherical surface 11, and a line d parallel to the piston top surface passing through the center of gravity of the ball. θ is 20′ or more, and a gap 12 is formed between the tip of the piston spherical portion 11 and the tip of the ball 6. Further, a spherical contact relief portion 13 that serves as a so-called oil pocket is provided inside the crimped position of the piston 5. The oil e is sealed in this spherical contact relief part 13 during caulking production to complete the caulking. Furthermore, a ball 6, a connecting rod 7, which serves as a direct actuation means for the piston 5. The rings 8 are integrally processed by performing a predetermined heat treatment, and then processing each ring 8 by welding. That is, the ball 6 is carburized and quenched, and the connecting rod 7 and ring 8 are heat treated by gas nitrocarburizing.
The ball 6 and the connecting rod 7. Projection welding f is performed on the abutting surfaces of the connecting rod 7 and the ring 8.

In this way, by crimping a part of the outer circumference of the piston, compared to the conventional type in which crimping is performed at the wide end of the piston, the weight can be reduced for the same overall piston length, resulting in lower vibration and noise. . Of course, the sealing properties are also good. Also,
In the spherical contact part, the contact position of the piston spherical part 11 and the ball 6 is limited so that the line connecting the center of gravity of the ball and a part of the piston spherical surface is at an angle of 20 degrees or more with respect to the base line. By arranging the gap 12 to a certain extent, the sliding load between the piston spherical portion 11 and the ball 6 is reduced, and the accuracy of the sphericity of the ball 6 and the piston spherical portion 11 can be relaxed. Moreover, there is an oil pocket adjacent to the caulking part! By arranging the spherical contact escape part 13, the initial break-in operation is also good, and the oil that is scattered at the caulking part enters through the gap of the caulking part that appears in the compression process, and oil lubrication is performed, resulting in wear resistance. (See Figure 10). Furthermore, by connecting the three points of the ball 6, connecting rod 7, and ring 8 through predetermined heat treatment and projection welding, the tensile strength of this connection is increased.
Moreover, it becomes possible to manufacture the connecting rod 7 and the ring 8 with good perpendicular accuracy. In addition, by increasing the hardness of the ring 8, the ring 8 itself can be made thinner, and from this point of view as well, the imaging performance is reduced.

Low noise can be measured.

<Effects of the Invention> As described above, the ball joint type piston device for a hermetic compressor of the present invention has the ability to swage the piston against the ball (
The connection is made at a part of the outer periphery of the piston other than the end, a gap is provided between the piston spherical part and the ball, and a spherical contact relief part (oil pocket) is provided adjacent to the caulking part. As the balls, connecting rods, and rings are assembled using projection welding, the piston drive has low vibration and noise, is highly wear resistant, is easy to manufacture, and is cheaper than reciprocating pistons. This has the effect of realizing a hermetic electric compressor using the device.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the main parts of the present invention, Fig. 2 is an explanatory view showing the piston crimping state of the conventional product, Figs. 3 and 4 are plan views showing the crimping part of the invention, and Fig. 5. 6 is a sectional view showing the positional relationship between the piston and the ball, FIG. 6 is an enlarged explanatory view of the same essential parts, and FIG. FIGS. 8 and 9 are cross-sectional views of the spherical contact relief part and explanatory diagrams showing the crimping order, FIG. 10 is an explanatory diagram of the state of oil scattering at the crimping position, FIGS. 11, 12, 13, FIGS. 14 and 15 are explanatory diagrams showing the relationship between the ball, connecting rod, and ring, and FIG. 16 is a sectional view of the device in use. DESCRIPTION OF SYMBOLS 1... Hermetic compressor, 4... Cylinder, 5... Piston, 6... Ball, 7... Connecting rod, 8... Ring, 11... Piston spherical part, 12...・Gap, 1
3... Spherical contact relief part, a... Caulking connection, b...
・Ball center of gravity, f...Projection welding. Patent applicant Sanyo Electric Co., Ltd. Tokyo Sanyo Electric Co., Ltd. Shu Higashifuji Electric Co., Ltd. Yukako Seiki Co., Ltd.

Claims (1)

[Claims] 1. In a ball joint type piston device in which a piston and a connecting rod that slide in a cylinder are arranged with a spherical joint, the connecting position of the ball and the piston with the connecting rod and ring attached to the rear part of the piston is The entire circumference of the piston is supported at a part other than the end of the outer circumference, or by caulking at three or more places, and the contact position between the piston spherical part and the ball is set between the center of gravity of the ball and a part of the piston spherical part. A ball joint type piston device for a hermetic compressor, characterized in that the angle between a line connecting the two and a line parallel to the piston top surface passing through the center of gravity of the ball is 20 degrees or more. 2. The ball joint type piston device for a hermetic compressor as claimed in claim 1, wherein the caulking joint has a spherical contact relief portion for oil sealing and strain relief inside the caulking. 3. A ball joint type piston device for a hermetic compressor according to claim 1, wherein the ball, connecting rod, and ring are attached by a predetermined heat treatment and projection welding.