JP4552125B2 - Pipe fitting - Google Patents

Description

  The present invention relates to a pipe joint in a gas pipe or the like, and more particularly to a pipe joint that connects a pipe and a pipe joint by a clamp bolt and a nut.

  Various types of pipe joints have been proposed. Patent Documents 1 and 2 are examples of pipe joints that connect pipes to each other, although fluids flowing through the pipes are different in liquid and gas.

  The pipe joint is provided with a packing for ensuring hermeticity (in this specification, "hermeticity" is regarded as a broad concept including "watertightness"). This packing is made of rubber or metal. Regardless of, etc., each part is composed of independent parts.

JP 2003-314775 A JP 2000-304174 A

  Another example of a known pipe joint sealing mechanism will be described with reference to FIG. In FIG. 4, one end of the pipe (52) is formed with a tapered pipe expansion part (52a) at the tip, and the taper pipe expansion part is in pressure contact with the taper end (54a) of the joint pipe (54) by the cap nut (53). It is concluded to. However, when there is little distortion of the taper portion or the taper portion, there is a problem that even if the cap nut is tightened, leakage is likely to occur.

  Furthermore, when the pipe (52) is a copper pipe, if it is tightened too much, it will be damaged and its airtightness will be reduced. Therefore, the tightening torque may be limited to a certain range using a special tool such as a torque wrench, or depending on the skill of the operator. It was normal to perform proper tightening.

  This invention is made | formed in view of the above, and makes it a technical subject to provide the pipe joint which a connection operation | work is completed very simply only by clamping | tightening a clamp bolt.

The pipe joint according to the present invention is composed of a clamp bolt 1 in which an annular metal packing 10 is integrally provided at the tip, a hollow cylindrical joint body 2, and a sleeve body 3 built in the joint body. The clamp bolt 1 is joined to the joint 4 for piping in a state where the sleeve body 3 is inserted into the joint body 2, and the metal packing 10 is placed inside the sleeve body 3. When the clamp bolt 1 is tightened, the metal packing 10 is press-fitted into the taper while rotating by screwing to tighten the tube A, and the press-fitting progresses into the taper. Accordingly, the rotation is prevented by the frictional resistance, and the metal packing is threaded from the joint 16 and divided.
According to such a configuration, the metal packing 10 is brought into close contact with the tapered portion by tightening the clamp bolt, so that highly accurate airtightness can be ensured.

  Further, the pipe joint according to the present invention is characterized in that a groove portion 11 is provided at a joint portion between the metal packing 10 and the clamp bolt 1.

According to such a configuration, since the metal packing 10 is easily cut and separated from the clamp bolt 1 by the groove portion 11, once the metal packing 10 is plastically deformed, high airtightness is maintained as it is even if the clamp bolt is loosened. Also, even if tightening too much like conventional separate packing, the packing will not be damaged and airtightness will not be deteriorated, and it is only necessary to tighten as much as possible without worrying about tightening torque. Is significantly improved.
In addition, since the metal packing is integrated with the clamp bolt, the metal packing can be arranged at a predetermined position with high accuracy. For this reason, mounting errors such as gas leakage due to the displacement of the packing are drastically reduced.

  Since the pipe joint according to the present invention is plastically deformed by the metal packing being threaded from the base when the clamp bolt is tightened and being pressed into the taper even after the cutting, high airtightness is obtained.

  Hereinafter, with reference to FIG. 1 thru | or FIG. 3, the Example of the pipe joint which concerns on this invention is described.

  FIG. 1 is a front view of a semi-longitudinal section of a pipe joint according to the present invention. This pipe joint is for connecting the pipe A and the joint 4, and includes a clamp bolt 1, a joint body 2, and a sleeve body 3.

  FIG. 2A is a half sectional front view of the joint body 2. The joint body 2 is a hollow cylindrical body having openings 22 and 23 at both ends, and female screws 20a and 20b for screwing the clamp bolt 1 and the pipe joint 4 are provided at both ends. The diameter of the opening is slightly larger on the clamp bolt side than on the piping joint side. Further, a hollow portion 21 is provided inside the joint body 2, and the sleeve body 3 is inserted into the hollow portion 21. The sleeve body 3 is inserted from the clamp bolt side.

  FIG. 2B is a half cross-sectional front view of the clamp bolt. The clamp bolt 1 is provided with a cavity 12 penetrating in the front-rear direction so that the tube A can be inserted therethrough, and an annular metal packing 10 such as a donut is integrally provided at the tip. The clamp bolt 1 is provided with a square head 13 for screwing at the rear end, and a male screw 14 that is screwed into the screw hole 20a at the tip of the joint body 2 at the middle. The metal packing 10 is integrally provided on a stepped shoulder 15 at the front end of the clamp bolt 1 via a joint 16, and a groove 11 including an annular slit is provided in the joint 16.

  FIG. 2C is a half sectional front view of the sleeve body 3. The sleeve body 3 is formed of a hollow small cylindrical body having both ends open, and the metal packing 10 at the tip of the clamp bolt 1 is inserted from the rear end port 32. A tapered portion 30 is provided on the inner peripheral surface slightly behind the rear end port 32, and a tapered portion 31 having a trumpet-shaped spread is provided on the inner peripheral surface of the front end port 33.

  The joint 4 for piping is unique to the side of an instrument body such as an air conditioner, and is inserted and screwed into the opening 23 at the rear end of the joint body 2 as shown in FIG. For this reason, a cavity 43 penetrating in the front-rear direction is provided in a peripheral body portion 42 having a male screw 41 to be screwed with the female screw 20b of the opening 23, and the tip portion is in surface contact with the tapered portion 31 at the other end of the sleeve body 3. A tapered portion 44 is provided so as to be in close contact with each other. A square head 45 for screwing is provided at the outer end of the joint 4, and a mounting screw 46 is provided at the base end.

  A method of joining the pipe A and the joint 4 for piping using the pipe joint according to the present invention will be described with reference to FIG.

  The sleeve body 3 is inserted from the clamp bolt 1 side of the joint body 2 and the clamp bolt 1 is screwed into the screw hole 20a at the rear end portion of the joint body 2 with the tube A inserted through the cavity 12 of the clamp bolt 1. Tighten with. The joint 4 for piping is screwed into the screw hole 20b at the front end of the joint body 2 and tightened to a predetermined position. When the clamp bolt 1 is tightened in this state, the metal packing 10 at the tip of the clamp bolt advances while rotating integrally with the clamp bolt, and is press-fitted into the tapered portion 30 of the sleeve body 3. For this reason, the more the metal packing 10 is brought into strong contact with the tapered portion 30 and press-fitted into the back, the stronger the frictional resistance in the rotational direction, and finally the rotation is prevented. If the clamping bolt 1 continues to be tightened even if the rotation is prevented, the metal packing 10 is divided so that it can be threaded by the shearing force in the rotational direction acting on the joint 16 with the stepped shoulder 15. Further, when the clamp bolt 1 is tightened strongly and the pushing is continued, the metal packing 10 is deeply pressed into the taper portion without rotating, so that the tube A is strongly tightened on the inner surface of the metal packing 10 and the sleeve body 3 is further tightened. Due to the pushing, the close contact between the tapered portion 31 and the tapered portion 44 on the piping joint 4 side is strengthened, and the airtightness is improved.

  The joint 16 of the metal packing 10 is designed to have a width, a wall thickness, and the like so that a shearing force is applied by tightening a clamp bolt. Furthermore, by providing the groove portion 11 formed of an annular slit in the joint portion, the metal packing 10 is properly divided as prescribed.

  3A and 3B are enlarged cross-sectional views showing the operation of the metal packing 10 provided at the joint 16 of the clamp bolt and the taper portion 30 of the sleeve body 3. When pushing forward with further tightening from FIG. 3 (a), the metal packing 10 is plastically deformed like a wedge as shown in FIG. 3 (b), and the air tightness of both the inside and outside is further enhanced. Can understand. Further, due to the division of the metal packing, high airtightness is maintained as it is even if the clamp bolt is subsequently loosened.

When the pipe joint according to the present invention was trial-connected with a refrigerant gas cylinder of an air conditioner, there was no gas leakage.
In the embodiment, a copper pipe was used when connecting to the refrigerant gas pipe of the air conditioner. For this reason, the pipe A is preferably a copper pipe. However, it is of course impossible to serve anything other than copper.

  As described above, the pipe joint according to the present invention has a great industrial applicability because simplification of mounting work and high airtightness can be obtained at the same time.

FIG. 1 is a front view of the pipe joint of the present invention, and the upper half is shown in cross section. 2A to 2C are front views of the joint body, the clamp bolt, and the sleeve body, respectively, and the upper half is shown in cross section. 3A and 3B are enlarged cross-sectional views in the vicinity of the tapered portion 30. FIG. (a) represents the state before plastic deformation of the metal packing, and (b) represents the state after plastic deformation. It is sectional drawing of the pipe joint of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Clamp bolt 2 Joint body 3 Sleeve body 4 Piping joint 10 Metal packing 11 Groove part 16 Joint part 30 Taper part

Claims (2)

A clamp bolt (1) integrally provided with an annular metal packing (10) at the tip, a hollow cylindrical joint body (2), and a sleeve body (3) provided in the joint body In the state where the sleeve body (3) is inserted into the joint body (2), the clamp bolt (1) is joined to the pipe joint (4), and the sleeve body ( 3) is provided with a tapered portion (30) in contact with the metal packing (10). When the clamp bolt (1) is tightened, the metal packing (10) is rotated by screwing. The pipe (A) is clamped by press-fitting into the taper part, and the rotation is prevented by frictional resistance as the press-fitting progresses into the taper part, so that the metal packing is threaded from the joint part (16) and divided. The pipe joint. It said metal gasket (10) and pipe joint according to claim 1, wherein the groove in the joint (16) (11), characterized in that provided between the clamping bolt (1).

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