JPH0547759B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an O-ring type joint used for piping of an automobile air conditioner.

(Prior Art) In recent years, the joints of piping connections in automobile air conditioners are being changed from flare-type joints to O-ring-type joints that use O-rings for sealing.

A conventional O-ring type joint will be explained with reference to FIGS. 3 and 4.

Figure 3 is a cross-sectional view of a conventional O-ring type joint.
In the O-ring type joint, an O-ring 2 is attached to the tube end side of the flange portion 1a of a tube end-processed pipe 1 in which a flange portion 1a is formed near the tube end by beading, and the O-ring 2 is attached to the tube end side of the flange portion 1a. After the union screw 4 fixed to the end of the pipe 3 to be connected is fitted from the side, the union nut 5 fitted to the pipe end processed pipe 1 is tightened into the union screw 4.

Fig. 4 is a cross-sectional view showing the pipe end processed part of the pipe 1, in which the side corner of the flange part 1b of the pipe end 1b has a small circular arc surface as shown by the broken line A in the figure. It has a simple shape.

Returning to FIG. 3, by tightening the union screw 4 and the union nut 5, the O-ring 2 attached to the tube end 1b is connected to the inner diameter chamfered surface 4a of the union screw 4 and the tube end 1b. It is compressed and fixed between the external surface of the flange portion 1a and the tube end side surface of the flange portion 1a, and exhibits a sealing effect.

FIG. 5 shows a configuration of a refrigeration cycle of an automobile air conditioner using such an O-ring type joint.

The refrigerant is adiabatically compressed by the compressor 7 driven by the engine 6 and becomes a high temperature and high pressure gas.
It is sent to a condenser 8 via a pipe 9. A liquid refrigerant cooled by outside air introduced by a fan is sent to a dry liquid receiver 10 through a pipe 11. The dehumidified liquid refrigerant is then sent via piping 13 to an evaporator 12 having an expansion valve (not shown). The refrigerant, which is adiabatically expanded by the expansion valve and becomes a low-temperature, low-pressure mist, absorbs heat from the indoor air of the car in the evaporator 12 and becomes a low-temperature, low-pressure gaseous refrigerant, which is transferred to the piping 14.
is returned to the compressor 7 by. O-ring type joints 15 are used at the connections between each device and the piping.

(Problems to be Solved by the Invention) However, with the above configuration, when fitting the O-ring 2 to the tube end 1b, the mounting position of the O-ring 2 cannot be determined, and the mounting position may be uneven. As a result, there was a problem of poor workability during piping connection work. There was also a problem in that the O-ring 2 fell off from the pipe end 1b during the work of sequentially connecting the component devices and the pipes.

The present invention solves the above-mentioned problems and provides an O-ring type joint for piping of an air conditioner for an automobile, which has good workability and always ensures a connection pipe.

(Means for Solving the Problems) In order to solve the above problems, the present invention forms an R groove on the outer circumferential surface of the base of the flange portion of the tube end portion to which the O-ring is attached.

(Function) With the above configuration, the O-ring fitted to the end of the end-processed pipe is securely attached to the corner of the flange part by the R groove, and there is no risk of it falling off, so the O-ring can be easily attached to the corner of the flange. Improved properties and stable quality.

(Example) An example of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a cross-sectional view showing a pipe end of an O-ring type joint according to the present invention, in which an R groove 1c is formed on the outer circumferential surface of the base of the flange portion 1a of the pipe end portion 1b.

FIG. 2 is a sectional view of an O-ring type joint using the pipe 1 with a machined end shown in FIG. After fitting into the R groove 1c formed at the base, the union screw 4 fixed to the connected pipe 3 is fitted into the pipe end 1b, and the union nut 5 and the union screw 4 are tightened. R groove 1c
When installed, the O-ring 2 is compressed and fixed between the chamfered surface 4a formed on the inner diameter of the tip of the union screw 4, the flat surface of the flange portion 1a, and the R surface of the R groove 1c, and serves as a seal.

The O-ring 2 fitted to the tube end 1b is connected to the R groove 1.
By inserting up to C, the position can be easily determined, and it will not fall off during work, resulting in good workability and stable quality.

The present invention is also compatible with conventional O-ring type joints.

(Effects of the Invention) As explained above, according to the present invention, the R-groove formed in the end of the end-processed pipe allows the end-processed pipe to be installed in a fixed position in close contact with the flange, and to prevent it from falling off during work. Since there is no problem, piping workability is improved and joint quality is stable.

Further, since the O-ring type joint according to the present invention is compatible with the conventional one, it can be replaced without changing the conventional piping design.

In the embodiment, the union screw 4 is fixed to the pipe 3 to be connected, but it goes without saying that the effect will be the same even if the union screw 4 is attached directly to each component.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a main part of a pipe with a processed end used in an O-ring type joint for piping of an automobile air conditioner according to the present invention, Fig. 2 is a cross-sectional view of an O-ring type joint according to the present invention, and Fig. 3 4 is a sectional view of a conventional O-ring type joint, FIG. 4 is a sectional view of a conventional pipe end, and FIG. 5 is a configuration diagram of a refrigeration cycle of an automobile air conditioner. 1... Pipe end processing pipe, 1a... Flange part,
1b...Pipe end, 1c...R groove, 2...O ring, 3...Connected pipe, 4...Union screw,
4a... Chamfered surface, 5... Union nut, 6...
...Engine, 7...Compressor, 8...Condenser, 9,
11, 13, 14... Piping, 10... Dry liquid receiver, 12... Evaporator, 15... O-ring type joint.

Claims (1)

[Claims] 1. An end-processed pipe with a flange formed near the end, an O-ring attached to the end of the end-processed pipe, and a union nut inserted from the non-processed end of the above-mentioned pipe with an end-processed end, In an O-ring joint for automotive air conditioner piping, which is composed of a union screw that fits into the pipe end, an R groove is formed on the cylindrical outer circumferential surface of the flange base where the O-ring is attached to the pipe end. An O-ring type joint for piping of an automobile air conditioner, characterized in that it has the following features: