JP2007192328A - Joint structure using metal seal member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint structure using a metal seal member having no problem in refrigerant permeability at high temperatures and which can facilitate coupling work of joint flanges. <P>SOLUTION: Out of a pair of first and second joint flanges 3 and 4, the second flange 4 is provided with a guide pin 9, and when the first and the second flanges 3 and 4 are coupled with a metal seal ring 10 interposed therebetween, the metal seal ring 10 is temporarily held by the guide pin 9. Thereby, even at high temperatures, a metal seal member having no problem in refrigerant permeability can be used, and when a pair of joint flanges are coupled with the metal seal member interposed therebetween, the metal seal member can be temporarily held by a holding means, so that the joint flanges can be coupled without the metal seal member falling off, and the coupling work of the joint flanges can be facilitated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a joint structure using a metal seal member in which an annular metal seal member is interposed between a pair of joint flanges.

  In recent years, natural refrigerants such as carbon dioxide (CO2) having a low global warming potential have been used in the refrigeration cycle of vehicle air conditioners. Since such a CO2 refrigerant is used at a higher pressure and a higher temperature than the current refrigerant, a high sealing performance is required for a connecting portion of a high-pressure pipe that supplies the refrigerant compressed by the compressor to a condenser, an expansion valve, or the like. For this reason, development of a resin O-ring that can withstand high pressure and high temperature is underway. However, even with a resin O-ring that can withstand such high pressure and high temperature, it is considered difficult to suppress refrigerant permeation.

  Therefore, for example, as shown in FIG. 13, a convex portion 105 is formed on one of a pair of joint flanges 103 and 104 d provided at the distal ends of the pipes 101 and 102 to be connected to each other, and a concave portion 106 is formed on the other. It has been studied to improve the sealing performance by arranging two resinous O-rings 107 and 108 between the fitting portions between the convex portions 105 and the concave portions 106 to form a W seal structure.

  However, when the two O-rings 107 and 108 are provided in this way, the high-pressure refrigerant leaks from the O-ring 107 on the tip side of the convex portion 105 over time due to long-term use of the air conditioner, and thus the two O-rings 107 are used. 108, there is a problem in that when the joint flanges 103 and 104 are disassembled during maintenance, the high-pressure refrigerant accumulated inside is blown out at once and a bursting sound is generated.

Therefore, in order to prevent the generation of a plosive sound while ensuring high sealing performance for the connecting portion of the high-pressure pipe, a single metal sealing member that is annular as disclosed in Patent Document 1 is used. It is desirable to clamp the metal seal member between the opposing surfaces of the joint flange.
JP-A-8-109987 (page 2, FIG. 1)

  However, since the metal seal member is less elastic and does not stretch, a groove cannot be provided at the end of the high-pressure pipe as provided in the convex portion 105 in FIG. Further, in a vehicle air conditioner, the connection of high-pressure piping is often in the horizontal direction, and the pair of joint flanges are arranged vertically. For this reason, in a joint structure using a conventional metal seal member, it is necessary to place the metal seal member between the vertical joint flanges and tighten the joint flanges, and the metal seal member easily drops at that time. The workability of connecting the joint flange to the joint becomes worse.

  The present invention has been made in order to solve the above-described problems. The object of the present invention is to use a metal seal member that has no problem with refrigerant permeability even at a high temperature and that can easily perform a joint flange coupling operation. It is to provide a joint structure.

  In the joint structure using the metal seal member according to the present invention, two tubular bodies are connected to each other by connecting a pair of joint flanges provided at the respective ends to each other, and between the opposing surfaces of each joint flange. In the joint structure in which the metal seal member is sealed concentrically with the tubular body, a holding means for temporarily holding the metal seal member is provided on one of the pair of joint flanges.

  In the present invention, since the metal seal member is used, there is no problem in refrigerant permeability even at high temperatures, and even when high pressure and high temperature CO2 is used as the refrigerant of the vehicle air conditioner, the sealing ability can be sufficiently exerted. .

  Further, when the pair of joint flanges are joined with the metal seal member interposed therebetween, the metal seal member can be temporarily held by one of the joint flanges by the holding means, so that the metal seal member is not dropped. The joint flange can be joined, and the joint work of the joint flange becomes easy.

  Furthermore, since the single metal seal member is used, no high-pressure refrigerant pool is formed, so that no burst noise can be generated even when the joint flange is disassembled.

  Embodiments of a joint structure using a metal seal member according to the present invention will be described below with reference to the drawings. Here, the connection part of the high-pressure piping of the vehicle air conditioner using CO2 as the refrigerant of the refrigeration cycle for cooling will be described as an example.

(First embodiment)
A first embodiment of the present invention is shown in FIGS. FIG. 1 is a cross-sectional view in a state in which a pair of joint flanges are coupled, and FIG. 2 is an end view of the joint flange as viewed from the direction A in FIG.

  As shown in FIG. 1, the joint structure of the present embodiment includes a pair of first and second high-pressure pipes 1 as one tubular body and a high-pressure pipe 2 as the other tubular body. The second joint flanges 3 and 4 are coupled and connected to each other.

  Here, the high-pressure pipe 1 and the high-pressure pipe 2 are arranged in a substantially horizontal direction, and the first and second joint flanges 3 and 4 are arranged in a substantially vertical direction.

  The first and second joint flanges 3 and 4 are formed in a rectangular shape (see FIG. 2) having a predetermined thickness, and mounting bolts 5 are attached to the four corners of the first joint flange 3, Screw holes 6 for screwing mounting bolts 5 are formed at the four corners of the two joint flanges 4. In addition, openings 7 and 8 communicating with the high-pressure pipes 1 and 2 are formed at the center of the first and second joint flanges 3 and 4.

  And between the opposing surfaces 3a and 4a of the 1st, 2nd joint flanges 3 and 4, the metal seal ring 10 as a cyclic | annular metal seal member is installed, and this metal seal ring 10 is the tubular bodies 1,2. It is structured so as to be sealed concentrically.

  The metal seal ring 10 has a predetermined thickness t (see FIG. 1) and an inner diameter D (see FIG. 2) that is sufficiently larger than the diameters 7 and 8 of the first and second joint flanges 3 and 4. It is formed in a ring shape. The metal seal ring 10 is mounted in a recess 4 b formed concentrically with the opening 8 on the facing surface 4 a of the second joint flange 4. The depth d of the recess 4b (see FIG. 1) is set to be smaller than the thickness t of the metal seal ring 10 (d <t).

  In the present embodiment, one guide pin 9 is provided as a holding means for temporarily holding the metal seal ring 10 in one second joint flange 4 of the pair of first and second joint flanges 3 and 4. .

  As shown in FIG. 2, the guide pin 9 is installed on the bottom surface of the recess 4 b and immediately above the opening 8. A metal seal ring 10 is hooked on the guide pin 9 and temporarily held.

  Further, a clearance hole 3b for receiving the tip end portion of the guide pin 9 is formed in the facing surface 3a of the mating first joint flange 3 when the first and second joint flanges 3 and 4 are coupled. .

  According to the joint structure of the present embodiment, the first joint flange 3 and the second joint flange 4 are joined by the guide pin 9 and the relief hole 3b, and then the mounting bolt 5 inserted through the first joint flange 3 is attached to the second joint. The metal seal ring 10 interposed between the joint flanges 3 and 4 is strongly pressure-bonded by being screwed into the screw hole 6 of the flange 4 and tightening. For this reason, high sealing performance can be secured between the openings 7 and 8 of the joint flanges 3 and 4 and between the high-pressure pipes 1 and 2.

  Therefore, according to the joint structure of this embodiment, there is no problem in refrigerant permeability even at high temperatures, and even when high pressure and high temperature CO2 is used as the refrigerant of the vehicle air conditioner, the metal sealing ring 10 provides a sealing capability. Can fully demonstrate.

  In addition, since the metal seal ring 10 is single, no high-pressure refrigerant pool portion is formed, and therefore, when the first and second joint flanges 3 and 4 are disassembled, the generation of a bursting sound is eliminated. Can do.

  In the present embodiment, when the first and second joint flanges 3 and 4 are joined with the metal seal ring 10 interposed therebetween, the metal seal ring 10 is temporarily held by the one second joint flange 4 by the guide pin 9. Therefore, the first and second joint flanges 3 and 4 can be joined without dropping the metal seal ring 10, and the joint work of both joint flanges 3 and 4 becomes easy. .

  Further, when the joint flange is coupled, the distal end portion of the guide pin 9 is inserted into the clearance hole 3b of the mating first joint flange 3, so that the distal end portion of the guide pin 9 interferes with the first joint flange 3. There is no. However, when the tip of the guide pin 9 is shortened so as not to protrude from the metal seal ring 10, the escape hole 3b is not necessary.

(Second Embodiment)
A second embodiment of the present invention is shown in FIG. FIG. 3 is an end view of the joint flange corresponding to FIG. Hereinafter, the same components as those in the first embodiment will be denoted by the same reference numerals, and description of overlapping portions will be omitted as appropriate.

  As shown in FIG. 3, the joint structure of the present embodiment is provided with two guide pins 9 </ b> A and 9 </ b> B as holding means for temporarily holding the metal seal ring 10.

  These two guide pins 9 </ b> A and 9 </ b> B are arranged symmetrically with a predetermined interval L with respect to a center line C that extends right above the opening 8.

  Therefore, also in the joint structure of this embodiment, an effect equivalent to that of the first embodiment having the same basic structure can be obtained. In particular, in this embodiment, when the metal seal ring 10 is hooked on the two guide pins 9A and 9B, the metal seal ring 10 can be stably held temporarily in a fixed position by the self-centering function. 10 can be easily mounted in a concentric circle with the high-pressure pipes 1 and 2, and the reliability of the seal can be improved.

(Third embodiment)
A third embodiment of the present invention is shown in FIG. FIG. 4 is a cross-sectional view in a state where a pair of joint flanges are coupled. Hereinafter, the same components as those in the first embodiment will be denoted by the same reference numerals, and description of overlapping portions will be omitted as appropriate.

  As shown in FIG. 4, the joint structure of the present embodiment is formed with a recess 3 c in which the metal seal ring 10 is disposed on the facing surface 3 a of the first joint flange 3, and the tip of the high-pressure pipe 1 is connected to the second joint flange. The protrusion 1a is protruded to the 4th side, and the protrusion 1a serves as a holding means for temporarily holding the metal seal ring 10.

  In addition, the opening 8 of the second joint flange 4 is enlarged in diameter so that the protruding portion 1a can be received. Thereby, when the 1st joint flange 3 and the 2nd joint flange 4 are combined, the protrusion part 1a will be inserted in the opening part 8 without interfering with the opposing surface 4a of the 2nd joint flange 4. FIG. .

  Also in the joint structure of this embodiment, since the metal seal ring 10 can be temporarily held on one joint flange side, the same effect as that of the first embodiment can be obtained. In particular, in the present embodiment, when the first joint flange 3 and the second joint flange 4 are coupled, the metal seal ring 10 can be temporarily held by being inserted into the outer periphery of the protruding portion 1a. A guide pin for hooking the seal ring 10 becomes unnecessary, and the cost can be reduced.

  In the present embodiment, the case where the concave portion 3c is formed on the first joint flange 3 side is shown. However, as shown in FIG. 5, the concave portion 4b is formed on the second joint flange 4 side as in the first embodiment. In such a case, the same effect can be obtained.

(Fourth embodiment)
A fourth embodiment of the present invention is shown in FIG. FIG. 6 is a cross-sectional view in a state in which a pair of joint flanges are coupled. Hereinafter, the same components as those in the third embodiment will be denoted by the same reference numerals, and description of overlapping portions will be omitted as appropriate.

  The basic structure of the present embodiment is the same as that of the third embodiment. As shown in FIG. 6, the recess 3c in which the metal seal ring 10 is disposed is formed on the facing surface 3a of the first joint flange 3, and the high-pressure pipe 1 The projecting portion 1a is used as a holding means for temporarily holding the metal seal ring 10. In addition, in the present embodiment, a circumferential groove 20 having a width that can fit the metal seal ring 10 is formed on the outer periphery of the distal end portion of the protruding portion 1a.

  Also in the joint structure of this embodiment, an effect equivalent to that of the third embodiment having the same basic structure can be obtained. In particular, in this embodiment, when the metal seal ring 10 is temporarily held on the protruding portion 1a of the high-pressure pipe 1 and the first and second joint flanges 3 and 4 are joined, the sliding portion tends to slip from the tip side of the protruding portion 1a. The metal seal ring 10 can be received by the circumferential groove 20.

  Therefore, even when the high-pressure pipe 1 is slightly tilted or vibrated when the first and second joint flanges 3 and 4 are joined, it is ensured that the metal seal ring 10 falls from the protruding portion 1a of the high-pressure pipe 1. It is possible to prevent the two joint flanges 3 and 4 from being joined more easily.

(Fifth embodiment)
A fifth embodiment of the present invention is shown in FIGS. FIG. 7 is a cross-sectional view in a state where a pair of joint flanges are coupled, and FIG. 8 is an enlarged cross-sectional view of a portion B in FIG. Hereinafter, the same components as those in the fourth embodiment will be denoted by the same reference numerals, and description of overlapping portions will be omitted as appropriate.

  The basic structure of the present embodiment is the same as that of the third embodiment. As shown in FIG. 7, the recess 3c in which the metal seal ring 10 is disposed is formed on the facing surface 3a of the first joint flange 3, and the high-pressure pipe 1 The projecting portion 1a is used as a holding means for temporarily holding the metal seal ring 10. In addition, in the present embodiment, a width that allows the metal seal ring 10 to be fitted to the outer periphery of the tip of the protruding portion 1a is provided, and the side wall 21 on the first joint flange 3 side is inclined as shown in FIG. A circumferential groove 20A having a substantially triangular cross section is formed.

  Also in the joint structure of this embodiment, the effect equivalent to 4th Embodiment which has the same basic structure can be acquired. In particular, in this embodiment, since the side wall 21 of the circumferential groove 20A is inclined, the metal seal ring 10 attached to the recess 3c of the first joint flange 3 when the first and second joint flanges 3 and 4 are joined. When the metal seal ring 10 is received by the circumferential groove 20A in an attempt to slide down from the front end side of the projecting portion 1a of the high-pressure pipe 1, the metal seal ring 10 is easily returned along the inclined side wall 21 toward the first joint flange 3. Therefore, the joint operation of both joint flanges 3 and 4 can be performed more easily.

(Sixth embodiment)
A sixth embodiment of the present invention is shown in FIG. FIG. 9 is a cross-sectional view in a state where a pair of joint flanges are coupled. Hereinafter, the same components as those in the fifth embodiment will be denoted by the same reference numerals, and description of overlapping portions will be omitted as appropriate.

  The basic structure of the present embodiment is the same as that of the fifth embodiment. As shown in FIG. 9, the recess 3c in which the metal seal ring 10 is disposed is formed on the opposing surface 3a of the first joint flange 3, and the high-pressure pipe 1 The projecting portion 1a is used as a holding means for temporarily holding the metal seal ring 10. In addition, in the present embodiment, a width that allows the metal seal ring 10 to be fitted to the outer periphery of the tip of the protruding portion 1a is provided, and the side wall 21 on the first joint flange 3 side is inclined as shown in FIG. A circumferential groove 20A having a substantially triangular cross section is formed, and the protruding amount S of the protruding portion 1a is further reduced so that the circumferential groove 20A is positioned in the vicinity of the recess 3c of the first joint flange 3. That is, the protruding portion 1a with the protruding amount S reduced together with the circumferential groove 20A is used as the holding means.

  In the above configuration, when the first and second joint flanges 3 and 4 are joined together, the mounting bolt 5 is screwed into the screw hole 6 and tightened while the metal seal ring 10 is hooked on the circumferential groove 20A. The metal seal ring 10 is pushed out from the circumferential groove 20 </ b> A by the four opposing surfaces 4 a and is attached to the recess 3 c of the first joint flange 3.

  Therefore, also in the joint structure of this embodiment, an effect equivalent to that of the fifth embodiment having the same basic structure can be obtained. In particular, in this embodiment, since the metal seal ring 10 can be locked from the beginning to the circumferential groove 20A, there is no need to worry about slipping of the metal seal ring 10, and the protruding portion 1a of the high-pressure pipe 1 is not affected. Since the length is shortened, the fitting operation of both joint flanges 3 and 4 becomes easy. Thus, in this embodiment, even if the protruding portion 1a of the high-pressure pipe 1 is shortened, the metal seal ring 10 can be prevented from falling off, so that the joint operation of the joint flanges 3 and 4 can be performed quickly and easily. be able to.

(Seventh embodiment)
A seventh embodiment of the present invention is shown in FIGS. 10 is a cross-sectional view in a state where a pair of joint flanges are coupled, and FIG. 11 is an enlarged cross-sectional view of a portion C in FIG. Hereinafter, the same components as those in the first embodiment will be denoted by the same reference numerals, and description of overlapping portions will be omitted as appropriate.

  The basic structure of this embodiment is substantially the same as that of the first embodiment, and as shown in FIG. 10, a guide pin 9 as a holding means for temporarily holding the metal seal ring 10 </ b> A is provided on the second joint flange 4.

  In this embodiment, as shown in FIG. 11, a metal seal ring 10A having a C-shaped cross section in which a slit 11 is formed on the inner peripheral side is used. This metal seal ring 10A is a metal seal having a high elastic force in the direction of thickness t, and is more elastic than the metal seal ring 10 (mud material) of other embodiments.

  Since the sealability can be improved by using such a metal seal ring 10A having excellent elasticity, in this embodiment, the mounting bolt 5 for connecting the first and second joint flanges 3 and 4 is provided with It is provided only on the upper part of one joint flange 3.

  Also in the joint structure of this embodiment, the effect equivalent to 1st Embodiment which has the same basic structure can be acquired. In particular, in this embodiment, since the metal seal ring 10 </ b> A having excellent elasticity is used, the first and second joint flanges 3 and 4 can be coupled with the mounting bolt 5 only at the upper part. Therefore, it is possible to simplify the coupling work of the first and second joint flanges 3 and 4 and to reduce the size and the number of parts of the first and second joint flanges 3 and 4. Cost can be reduced.

  In the present embodiment, as shown in the second embodiment, two guide pins 9A and 9B may be provided.

(Eighth embodiment)
FIG. 12 shows an eighth embodiment of the present invention. FIG. 12 is a cross-sectional view in a state where a pair of joint flanges are coupled. Hereinafter, the same components as those in the seventh embodiment will be denoted by the same reference numerals, and description of overlapping portions will be omitted as appropriate.

  The basic structure of the present embodiment is the same as that of the seventh embodiment. The metal seal ring 10A having a cross-section C shape is temporarily held by a guide pin 9 as a holding means, and the mounting bolt 5 is attached to the upper portion of the first joint flange 3. Only provided. Furthermore, in this embodiment, the fulcrum part 30 which can be engaged / disengaged is provided in the lower part of the 1st, 2nd joint flanges 3 and 4. As shown in FIG. The fulcrum portion 30 includes a support portion 31 formed with a V-shaped recess 31a that protrudes from the lower portion of the opposing surface 4a of the second joint flange 4 toward the first joint flange 3 and opens upward, and the first joint flange 3 It is comprised by the convex part 32 which protrudes below the opposing surface 3a side.

  When the first and second joint flanges 3 and 4 are coupled, the mounting bolt 5 is screwed into the screw hole 6 and tightened with the convex portion 32 locked to the concave portion 31 a of the support portion 31. Thereby, since the upper part of the first and second joint flanges 3 and 4 is fastened by the mounting bolt 5 with their lower parts supported by the fulcrum part 30, the first and second joint flanges 3 and 4. The coupling force is further increased, and the coupling by the mounting bolt 5 only at the upper part can be performed more reliably.

  Also in the joint structure of this embodiment, the effect equivalent to 7th Embodiment which has the same basic structure can be acquired. In particular, in this embodiment, since the fulcrum part 30 which can be freely engaged and disengaged is provided at the lower part of the first and second joint flanges 3 and 4, the coupling force of the first and second joint flanges 3 and 4 is further increased. Can do. Therefore, the first and second joint flanges 3 and 4 can be more reliably coupled than the coupling by the mounting bolt 5 only at the upper portion as in the seventh embodiment.

  In the present embodiment, as shown in the second embodiment, the two guide pins 9A may be provided as 9B.

  The above-described joint structure using the metal seal member according to the present invention is not limited to the above-described embodiments, and various other embodiments can be employed without departing from the spirit of the present invention. . For example, the joint structure of the present invention is not limited to the connection of a high-pressure pipe of a vehicle air conditioner, but can be used for other pipe joint parts, and is particularly excellent when applied to a pipe for high-pressure fluid. There is an effect.

Sectional drawing in the state which couple | bonds a pair of joint flange in 1st Embodiment of this invention. The end view of the joint flange seen from A direction in FIG. The end elevation of the joint flange corresponding to Drawing 2 in a 2nd embodiment of the present invention. Sectional drawing in the state which couple | bonds a pair of joint flange in 3rd Embodiment of this invention. Sectional drawing in the state which couple | bonds a pair of joint flange which shows the modification of 3rd Embodiment of this invention. Sectional drawing in the state which couple | bonds a pair of joint flange in 4th Embodiment of this invention. Sectional drawing in the state which couple | bonds a pair of joint flange in 5th Embodiment of this invention. The expanded sectional view of the B section in FIG. Sectional drawing in the state which couple | bonds a pair of joint flange in 6th Embodiment of this invention. Sectional drawing in the state which couple | bonds a pair of joint flange in 7th Embodiment of this invention. The expanded sectional view of the C section in FIG. Sectional drawing in the state which couple | bonds a pair of joint flange in 8th Embodiment of this invention. Sectional drawing which shows the conventional joint structure.

Explanation of symbols

1 High-pressure piping (tubular body)
1a Protruding part (holding means)
2 The other high-pressure pipe (tubular body)
3 First joint flange 4 Second joint flange 9, 9A, 9B Guide pin (holding means)
10, 10A Metal seal ring (metal seal member)

Claims (1)

The two tubular bodies (1, 2) are connected to each other by connecting a pair of joint flanges (3, 4) provided at the respective ends, and facing surfaces (3a) of the respective joint flanges (3, 4). 4a) In a joint structure for sealing an annular metal seal member (10) interposed between the tubular bodies (1, 2) substantially concentrically,
A joint structure using a metal seal member, wherein a holding means (9) for temporarily holding the metal seal member (10) is provided on one of the pair of joint flanges (3, 4).