JP3043930U - Pipe fitting structure - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To minimize gas leakage as much as possible by improving the structure of pressurization applied to a rubber packing, mainly in a pipe joint in a pipe of an air conditioner for a vehicle such as an automobile. Provide the structure of the joint. The present invention is directed to a union bolt and a nut.
In a joint formed by interposing a rubber packing 5 between a pair of pipes 1 and 2 which are joined by screwing together one pipe 1
Is provided with a bent ridge 1b which comes into contact with the inner wall of the nut, and a step portion 1a for sandwiching the rubber packing 5 is formed at the tip thereof, and the other pipe 2 faces the step portion of the pipe. Step 2a with a width that allows rubber packing 5 to be clamped in position
To form A rubber packing 5 having a circular cross section, which is interposed in a square space formed by the step portions 1a and 2a facing each other, is deformed in accordance with the progress of screwing of the union bolt 4 and the nut 3 so as to be pressed in the left and right and up and down directions. Consists of

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention mainly relates to a pipe joint in a pipe of an air conditioner for a vehicle such as an automobile.

[0002]

[Prior art]

 2. Description of the Related Art Conventionally, a joint in a pipe of an air conditioner for a vehicle such as an automobile has, for example, as shown in FIG. 2, a rubber between a pair of pipes a and b joined by screwing a union bolt c and a nut d. In a joint formed by interposing packing e, one pipe is provided with a bent ridge that contacts the inner wall of the nut at a part of the end, and a U-shape for inserting a rubber packing at the tip of the bent ridge. A groove is formed, and a pipe that covers the groove extends on the other pipe. Therefore, the rubber packing is mounted in a space formed by the groove and the cylindrical body covering the groove so as to be vertically sandwiched.

However, in such a conventional technique, when processing a concave groove, when drawing with a rolling roller or the like, friction occurs between the roller and a metal roller, causing peeling or peeling on the pipe surface. May cause scratches. On the other hand, the force applied to the rubber packing inserted in the space formed by the U-shaped groove and the cylindrical body covered therewith is not uniform in the vertical direction and is often biased to one side. Then, if there is a part where there is peeling or scratches on the surface due to the clamping pressure of the rubber packing, it will not be compensated by the rubber elasticity, and gas leakage will occur from there, which will extend the life of the refrigerant in the air conditioner. It shrinks significantly. By the way, the regulations for gas leakage in automobiles are extremely strict conditions of 0.2 mg / year or less.

[0004]

[Problems to be solved by the device]

 The present invention has been made based on the above-mentioned circumstances, and it is an object of the present invention to improve the structure of the pressurizing applied to the rubber packing to provide a structure of a joint with as little gas leakage as possible.

[0005]

[Means for Solving the Problems]

 The proposed pipe joint structure is a joint in which a rubber packing is interposed between a pair of pipes that are joined by screwing a union bolt and a nut, and one pipe has a bent ridge that contacts the inner wall of the nut. A step portion for sandwiching the rubber packing is formed at the end of the pipe, and a step portion is formed on the other pipe at a position facing the step portion of the pipe with a width capable of sandwiching the rubber packing. It is characterized in that the rectangular space formed by facing the stepped portions is deformed according to the progress of screwing of the union bolt and the nut to press the rubber packing having a circular cross section in the left and right and up and down directions.

[0006]

[Embodiment of the invention]

 The present invention is a part of piping of an air conditioner for a vehicle such as an automobile, and the air conditioner forms a circulation path from the compressor to the condenser, the capillary tube, and the evaporator and then back to the compressor. However, the joint of the present invention is used as a joint for a part of the pipe that connects the various parts.

The joint includes a pair of pipes 1 and 2, a union nut 3 and a bolt 4 for joining the pipes 1, and a rubber packing 5 interposed between the pipes 1 and 2.

[0008] One pipe 1 is provided with a bent ridge 1b which comes into contact with an inner wall of a nut 3 described later at a part of its end, and a step 1a for sandwiching a rubber packing 5 is formed at the tip thereof. The other pipe 2 extends from a tip end near the bent ridge 1b and forms a step 2a with a width such that the rubber packing 5 can be sandwiched between the pipe 2 and the step 1a of the pipe 1. The square space formed by the step portions 1a and 2a of the pair of pipes 1 and 2 has a shape in which a rubber packing having a circular cross section has four contact points vertically and horizontally by the step portions 1a and 2a. To do. For example, for a rubber packing 5 having a circular cross section, the height is equal to or slightly larger than the circular diameter of the rubber packing 5, and the width is smaller than the circular diameter. As the nut 3 and the bolt 4 are screwed together, the square space area formed by the step portions 1a and 2a is deformable.

Next, a union nut 3 is provided on the outer side of the pipe 1 having the bent ridge 1b. The nut 3 has a hole 3a through which the pipe 1 can penetrate and a wall surface on the inner side thereof. Is a side wall 3b which the bent ridge 1b of the pipe 1 comes into contact with and engages with, and a female screw 3c which is screwed into a union bolt 4 described later is engraved on the inner wall surface. On the other hand, the bolt 4 is provided with a male screw 4c which is screwed to the female screw 3c of the nut 3 on the outer side and a gap 4a which supports the cut portion 2a of the pipe 2 on the inner side. To form a step 4b for supporting the gap 2b for adjusting the diameter of the pipe 2.

The rubber packing 5 is formed by an elastic body of a ring having a size capable of engaging with the cut portion 1a of the pipe 1, has a circular cross section, and has a diameter of the cut portion 1a of the pipes 1 and 2. , 2a is determined relative to the square space formed by.

Next, the operation of this embodiment will be described. When joining the joint of the present invention, the male screw 4c of the union bolt 4 engaged with the other pipe 2 is screwed to the female screw 3c of the union nut 3 engaged with the end of the pipe 1 as in the conventional joint. Wear, rotate the nut 3 side, and proceed with mutual screwing. Then, the gap 4a formed on the bolt 4 pushes the cut portion 2a of the pipe 2, and the pipe 2 advances in the direction of the depth of the nut 3 (leftward in the drawing).

Then, a quadrangular space is formed between the broken portion 1 a of the pipe 1 and the broken portion 2 a of the pipe 2, and the area of the quadrangular space is associated with the union nut 3 and the bolt 4 being screwed together. The space area gradually narrows. In the process of narrowing the rectangular space, first, the width direction of the rubber packing 5 is narrowed, the circular cross section is deformed in the left-right width direction, and the deformation causes the rubber packing to elastically deform in the vertical direction, The part that extends up and down is pressed against the upper and lower walls of the square space. Then, when the union nut 3 and the bolt 4 are further screwed together, the circular cross section of the rubber packing 5 is deformed into a shape conforming to the shape of the square space, and the cut portion 1a of the pipe 1 and the cut portion 2a of the pipe 2 are The pressure narrowed from the left and right lateral directions and the pressure from the vertical direction due to the deformation are generated, and the pressure at the four points increases in proportion to the progress of screwing.

As a result, if a leak pressure is generated in the pipe 1 and the pipe 2 and the refrigerant gas reaches the rubber packing 5, at that time, even if a surface flaw due to rolling roller processing etc. is left at the cut portion. The leakage of the gas is sealed by the pressure from the left and right when there is a scratch in the up and down direction and by the pressure from the up and down when there is a damage in the lateral direction, and is not leaked.

[0014]

[Effect of the invention]

 The present invention relating to the above-described structure and operation is capable of bringing the rubber packing having the circular cross section into contact with the four wall surfaces forming the square space by simply screwing the union bolt and the nut. It is a device that is highly practical in that it can completely prevent the leakage of water, has a simple structure for realizing it, and is easy to manufacture.

[0015]

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view showing a joint structure of the present invention.

FIG. 2 is a partially cutaway sectional view showing a conventional joint structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 pipe 1a step part 1b bent ridge 2 pipe 2a step part 2b step 3 nut 3a hole 3b side wall 3c female screw 4 union 4a, 4b step 4c male screw 5 rubber packing

Claims (1)

[Utility model registration claims] 1. A joint formed by interposing a rubber packing between a pair of pipes joined by screwing a union bolt and a nut, wherein one pipe is provided with a bending ridge that contacts an inner wall of the nut. A step portion for sandwiching the rubber packing is formed at the end thereof, and a step portion is formed on the other pipe at a position facing the step portion of the pipe with a width capable of sandwiching the rubber packing. A pipe joint structure characterized in that a rubber packing having a circular cross section, which is provided in a square space formed by facing each other, is deformed in accordance with the progress of screwing of a union bolt and a nut so as to make pressure contact in the left and right and up and down directions. .