JPS58122392A - Assembly method of suction pipe of rotary type compressor - Google Patents

Abstract

PURPOSE:To ensure a seal function by expanding a pipe from inside after freely coupling a shrinked pipe section with a gas suction hole so as to bring the pipe outer periphery into close contact with the inner tube of the gas suction hole. CONSTITUTION:A spinning section 22a at one end of a suction pipe 22 is inserted into a gas suction hole 21 opened by drill boring. The tip 22b of the suction pipe 22 is brought into contact with the stepped section 21a of the gas suction hole 21. Then, the spinning section 22a of the suction pipe 22 is expanded by use of an expanding jig 23. That is, the expanding jig 23 is set to the outer periphery surface 2b of a seal case 2 so as to cover the protective pipe 4 outer periphery of the seal case 2, thus ensuring the seal function.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an efficient mechanical sole structure for a suction pipe that allows a closed case and a compressor main body to be brought close to each other and directs low-temperature gas from outside the closed case to the compressor main body.

As a known example of a conventional mechanical seal structure for a suction pipe, there is a structure shown in FIGS. 1 and 2.

That is, in FIG. 1, 1 is a compressor main body, 2 is a closed case, 3 is a cylinder, 4 is a protection pipe, and 5 is a suction pipe. The compressor main body 1 has a cylinder 3 as its core, a lower bearing 6 is attached to the lower side, an upper bearing 7 is attached to the upper side, a roller 8 is arranged inside the cylinder 3, and a rotating shaft supported by the lower and upper bearings. 9 and the roller 81d are slidably fitted together. Further, a vane (not shown) whose tip is in contact with the outer diameter of the roller 8 is assembled by pressing the back surface of the vane with a spring (not shown), and the vane is assembled into a vane slot (not shown) cut into the cylinder 6. (not shown) with precision fit and assembly. Above the rotating shaft 9, an electric motor 1
The rotor 10a of No. 0 is shrink-fitted and placed at the same position as the motor stator 10b which is previously joined inside the sealed case 2. As shown in FIG. 2, the mechanical seal structure of the suction pipe 5 consists of a suction hole 6a that opens into the cylinder 6 of the compressor body 1 assembled as described above, and a burring portion formed in the airtight case 2. 2a was brazed. With the inner diameter centers of the protection pipe 4 aligned, the suction pipe 5, which has an outer diameter smaller than the maximum diameter of the tapered suction hole 6a but still larger than the minimum diameter, is passed through the inner diameter of the protection pipe 4 as shown in FIG. Press in as shown. As a result, the suction pipe 5 is temporarily deformed from the original shape shown by the broken line to the shape shown by the solid line from an arbitrary position according to the tapered shape of the suction hole 3a, and a mechanical seal structure is formed in which the contact surface between the two forms the sealing surface. be. Regarding the dimensional relationship between the protection pipe 4 and the suction pipe 5, there is a certain amount of gap between them, taking into account variations in position during assembly, and the position of the end surface 5a of the suction pipe 5 and the end surface 4a of the protection pipe 4 is is on the same position line, and it is customary to insert the piping 11 of the unit mounting this rotary complete compressor into the suction pipe 5 as shown in the figure, as shown by the dashed line, and simultaneously seal it by brazing. In the above-mentioned suction/ζ-eve assembly structure of the conventionally known rotary complete compressor,
It has the following drawbacks. That is, since the suction hole 5a of the cylinder 3 can be cleaned only by increasing the pressure of the suction vibrator 5 to improve the surface roughness of the inner diameter, heavy cutting is not possible and is a low-efficiency operation.

In addition, in order to uniformly control the inner diameter accuracy of the tapered hole, it is necessary to control the wear of the hammer or to keep the depth of cut constant, which requires detailed adjustment work. In addition, since the suction pipe 5 is usually made of soft copper ζ-ebe, etc., vertical flaws are generated in that direction when the pipe 5 is press-fitted, which causes leakage and greatly reduces reliability. However, if the press-fit length is increased to avoid this problem, the press-fitting force will increase significantly, which will require precision accuracy.

6. It had drawbacks such as deformation of the inner diameter.

The object of the present invention is to eliminate the above-mentioned drawbacks of the conventional rotary unit compressor suction pipe assembly method and to provide a reliable mechanical seal structure by assembling parts with normal general machining accuracy.

In other words, the gas suction hole on the compressor body side is drilled to the extent of drilling, which is the most common method of drilling, and the suction pipe is made by spinning one end of a straight copper pipe, and cutting the constricted pipe part. After fitting into the gas suction hole, the pipe is expanded from the inside diameter side, and the outside diameter of the pipe is brought into close contact with the inside diameter of the gas suction hole to provide a sealing function. This is what we aim to achieve.

An embodiment of the present invention will be described below with reference to FIGS. 3 to 7. 21 is a gas suction hole of the compressor main body 1, 22 is a suction pipe, and the other parts are the same as in the conventionally known example.

Figures 6 and 4 show the state before the suction pipe expansion seal of the present invention, that is, a part of the compressor main body 1 (cylinder 6 in the figure) is opened with an IJ 7 and a gas One end of the suction pipe 22 is inserted into the suction hole 21.

Insert the second/gating part 22a. The leading end 22b of the suction/ζ eve 22 is connected to the stepped portion 2 of the gas suction hole 21 as shown in FIG.
1a, or as shown in FIG. 4, the opening end 21b of the gas suction hole 21 is engaged with the stepped portion 22c between the spinning portion 22a of the suction pipe 22 and the original outer diameter portion 22b. Thereafter, the spinning portion 22a of the suction pipe 22 is expanded using a tube expansion jig 2, as shown in FIGS. 5 to 7.

(See 1. Fig. 5 to Fig. 7 all show the stepped portion 22c of the suction pipe 22 shown in Fig. 4 above).
The method of locking in b is shown as a representative example).

That is, the tube expansion jig 23 is set on the outer diameter portion 2b of the sealed case 2 so as to cover the outer diameter of the protection/Z-ive 4 of the sealed case 2. FIG. 6 shows the state in which the suction pipe 22 is expanded, and the tube expansion part 23a of the tube expansion jig 25 has a spherical surface, which minimizes the tube expansion pressure.

The ability to follow the inner diameter properties (straightness, surface roughness, etc.) of the gas suction hole 21 is taken into consideration. The maximum diameter dimension of the expanded pipe portion 23a is appropriately selected within a range larger than [inner diameter of gas suction hole 11 - wall thickness of spinning section x 2].

That is, the spinning part 22a of the suction pipe 22 is the expanded pipe part 2.
3a, it expands and is pressed against the inner diameter surface of the gas suction hole 21. Moreover, from a microscopic perspective, a portion of the suction pipe 22 made of a copper pipe or the like digs into the drill cutting marks formed on the inner diameter of the suction hole 21. FIG. 7 shows a state in which the pipe expansion has been completed and the pipe 11 of the unit in which the rotor 17 complete compressor of the present invention is mounted, the suction pipe 22 and the protection pipe 4 are brazed at the same time as in the conventionally known example.

According to the present invention, compared to the conventional method of assembling the suction pipe of a rotary unit compressor, even if the surface roughness accuracy of the inner diameter of the gas suction hole 21 of the compressor body is low, the suction pipe 22 and the gas The inner diameter of the suction hole 21 has good followability and sealing is reliable.

Therefore, the conventional work using a taper reamer, which is often inefficient in terms of workability and dimensional control, can be completed by simply drilling. It is a trench, because it avoids the occurrence of vertical flaws that impair sealing performance due to the conventional press-fitting of the entire soft pipe.
Improves reliability of gas leaks. However, since the present invention uses a spherical tube expansion jig to reduce tube expansion stress due to line contact, this has a large impact on compressor performance, resulting in damage to the accuracy of the inner diameter. It is important to avoid such negative effects. Therefore, the practical effect of the present invention on a rotary compressor is extremely large in terms of processing efficiency and reliability improvement.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an example of the structure of a conventionally known rotary complete compressor, FIG. 2 is a side sectional view showing an example of the conventionally known suction pipe mechanical seal structure of the compressor in FIG. Fig. 4 is a side sectional view showing two embodiments of the assembled structure of the present invention before pipe expansion/ru, and the assembled state, and Figs. 5 to 7 show an embodiment of the suction pipe expansion work according to the present invention. FIG. 21...Gas suction hole, 21a...Stepped part, 21b,...
End face with gas suction hole, 22-・-Suction pipe, 22a・
Spinning part, 22b...Tip of suction pipe, 22c...
・Step part, 23 ・Pipe expansion jig, 26a, ・Pipe expansion part. First of all! 32' E3ω Fig. 4 6 F7 (2) F5 Fig. 11 -23

Claims (1)

[Claims] 1. Align the gas suction hole opened in a part of the compressor body built in the sealed case with the protective pipe attached to the sealed case, and insert the inner diameter of the protective pipe into the gas suction hole, This is a method of mechanically sealing the suction pipe. After inserting the stepped part of the suction pipe, which has an outside diameter of the stepped part smaller than the inside diameter of the gas suction hole, into the gas suction hole of the compressor body, A method for assembling a suction pipe for a rotary complete compressor, characterized in that the pipe is expanded from the inside diameter side, and the inside diameter of the gas suction hole and the outside diameter of the stepped part of the suction pipe are brought into close contact. 2. The rotary complete compressor according to claim 1, wherein the suction pipe is expanded by a burnishing method using a spherical expansion jig as a method for expanding the inner diameter of the stepped portion of the suction pipe. Suction pipe assembly method.