JP2007192270A - Pipe joint structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive pipe joint structure capable of preventing a joint block from levitating due to internal pressure, ensuring sufficient sealing even if the joint block is inclined, and reducing leakage. <P>SOLUTION: A sealing member 50 has a skirt part 51 extending in the axial direction and a flange part 52 extending in the radial direction. A protruding part 32 as a plug part and a diameter expanded part 41 as a socket part are provided in a male side block 10A and a female side block 20A, respectively, and the sealing member is provided between the plug part and the socket part which are mutually fitted in a recessed and projecting manner to seal in the axial direction and the radial direction. A positioning projecting part 70 and a positioning recessed part 24 are provided in the male side block and the female side block, respectively. When fitting both blocks mutually in a recessed and projecting manner, these positioning projecting and recessed parts are also fitted mutually in a recessed and projecting manner. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a pipe joint structure of a high-pressure pipe that transports a fluid such as gas or liquid, and is particularly suitable for a pipe joint structure used in a refrigeration cycle that uses carbon dioxide (CO ₂ ) as a refrigerant.

In recent years, in a compression refrigeration cycle of an air conditioning system of a vehicle or a house, one using CO ₂ as a refrigerant has been proposed and embodied. In the refrigeration cycle that uses CO _2, CO ₂ is characterized by operating at super operate in critical state, high pressure of about 7 to 10 times as compared to the conventional fluorocarbon refrigerant cycle. Therefore, leakage of the refrigerant from the pipe joint structure of the pipe used in the refrigeration cycle using CO ₂ is more likely to occur than in the past. Furthermore, in a conventional refrigeration cycle using a fluorocarbon refrigerant, a general-purpose rubber seal was used for the pipe joint structure, but CO ₂ itself has a small molecular weight and a large permeability coefficient to the rubber material. Will pass through. Therefore, the leakage of the CO ₂ refrigerant cannot be prevented simply by using a rubber seal.

For this reason, in order to prevent leakage of CO ₂ refrigerant from the pipe joint structure, a pipe joint structure using a metal seal instead of a rubber seal has been proposed (see Patent Document 1). In this Patent Document 1, protrusions are formed in the circumferential direction on the seal surfaces of a pair of joint blocks, and the metal seal is formed by a pair of joint blocks so that the protrusions are pressed against a metal seal having a rectangular cross section. These are clamped and bolted to secure the seal surface pressure only by the axial force of the bolt. For this reason, when the joint block is deformed and floated by the internal pressure, there is a problem that the seal surface pressure cannot be ensured and a seal failure occurs immediately.

  Moreover, in patent document 1, the positioning pin is provided in the joint block, and position alignment of a pair of joint block is performed. However, in Patent Document 1, since the bolt and the positioning pin are provided on the same side with respect to the seal portion, there is a problem that the positioning pin does not contribute to prevention of the joint block from being lifted by the internal pressure.

JP 2004-205041 A

  The present invention has been made in view of the above problems, and its purpose is to prevent the joint block from floating due to internal pressure, and to ensure a sufficient seal even when the joint block is tilted. It is to provide a joint structure.

This invention provides the pipe joint structure as described in each claim of a claim as a means for solving the said subject.
In the pipe joint structure according to claim 1, the seal member 50 includes a skirt portion 51 extending in a cylindrical shape or a tapered cylindrical shape in the axial direction and a flange portion 52 extending in an annular shape in the radial direction. The male blocks 10A and 10B are provided with plug portions 32 and 16, and the female blocks 20A and 20B are provided with socket portions 41 and 21, respectively. The seal member 50 is interposed between the seal member 50 in the axial direction and the radial direction, so that the skirt portion 51 of the seal member 50 is formed even if the block is inclined due to the internal pressure in the pipe. It is possible to prevent the seal member from floating when hitting the plug portion or the socket portion.

In the pipe joint structure according to claim 2, the plug portion of the male block is tapered slightly in a tapered shape, and the socket portion of the female block is slightly expanded in diameter as it goes to the tip. The taper is formed, and the skirt portion 51 of the seal member interposed between the plug portion and the socket portion is also formed in the same manner, so that the male side block of the seal member 50 is formed. Attaching to and removing from the plug portions 36 and 16 is improved. Moreover, the sealing performance of the sealing member is improved.
In the pipe joint structure according to the third aspect, the three taper angles of the plug portion, the socket portion, and the skirt portion of the seal member are made substantially the same, whereby the attachment / detachment property of the seal member 50 is further improved. .

In the pipe joint structure according to claim 4, one male block 10A, 10B is provided with plug portions 32, 16 and positioning convex portions 70, 17, and the other female block 20A, 20B is provided with the other female block 20A, 20B. Socket portions 41 and 21 and positioning recesses 24 are provided, and the plug portion and the socket portion and positioning protrusions and positioning recesses are respectively fitted with recesses and projections. Both blocks can be easily positioned. Further, the block can be prevented from being lifted by the internal pressure in the pipe.
The pipe joint structure according to claim 5 is such that the uneven fitting position of the positioning convex portion and the positioning concave portion is located on the opposite side of the bolt 80 with respect to the concave and convex fitting position of the plug portion and the socket portion. Thus, even if the block is lifted by the refrigerant pressure in the pipe, the positioning convex portion and the positioning concave portion are caught to prevent the block from floating.

The pipe joint structure according to claim 6 is such that the projection height H of the positioning convex portion is higher than the projection height h of the plug portion, whereby the male side block and the female side block are concavo-convexly fitted. In this case, the block can be positioned by the positioning convex portion before the tip of the plug portion contacts the seal surface of the female block, so that the seal portion of the female block can be prevented from being damaged.
In the pipe joint structure according to the seventh aspect of the present invention, the positioning convex portion is a pin 70 implanted in the male side block. This increases the number of parts but facilitates processing.

In the pipe joint structure according to the eighth aspect, the positioning convex portion 17 is formed integrally with the male block, and therefore, the block itself is formed rather than crimping another component such as the pin 70 to form the convex portion. Providing the projections 17 by machining can reduce the number of parts and assembly costs, and is low in cost.
In the pipe joint structure of claim 9, the plug portion of the male block is formed by the protruding portion 32 of the male pipe 30 connected to the male block, and the socket portion of the female block is formed on the female block. It is formed by the enlarged diameter part 41 of the female side pipe 40 to be connected. This allows the pipe to be pressed and caulked with the block, and does not require precise cutting of the seal part. In addition, since it is not necessary to braze the pipe, it can be manufactured at low cost.

In the pipe joint structure of claim 10, the protruding portion 16 is integrally formed with the male block 10B as the plug portion of the male block, and the concave portion 21 is formed in the female block 20B as the socket portion of the female block. Thereby, a plug part and a socket part can be formed by cutting.
In the pipe joint structure according to the eleventh aspect, the packing 60 is disposed on the outer periphery of the seal member 50, whereby corrosion due to water intrusion can be prevented. In addition, sealing failure due to freezing of the intruding water can be prevented.

In the pipe joint structure of claim 12, the packing 60 is made of a material having higher elasticity than metal materials such as rubber, resin, and elastomer, and the sealing effect is further improved by using the elastic material in this way. be able to.
In the pipe joint structure according to the thirteenth aspect, the material of the packing 60 is specified as EPDM, and the material cost of the packing can be reduced.
In the pipe joint structure according to the fourteenth aspect, the cross-sectional shape of the packing 60 is a quadrangle, and the space required in the radial direction can be made smaller than when the packing is an O-ring, and the entire pipe joint structure can be downsized.

Hereinafter, a pipe joint structure according to an embodiment of the present invention will be described with reference to the drawings. The pipe joint structure of the present invention is suitable for a pipe joint structure of a high-pressure pipe in which the pressure inside the pipe is, for example, about 15 MPa, like a refrigeration cycle of a vehicle air conditioner using carbon dioxide (CO ₂ ) refrigerant. However, the present invention is not limited to this, and it is also effective for a pipe joint structure of a low-pressure pipe having an internal pressure of about 2 MPa, such as a refrigeration cycle using another refrigerant such as R134a. Moreover, it is effective not only for the refrigeration cycle but also for pipe joint structures of all piping systems such as gas pipes and oil pipes.
FIG. 1 is a sectional view of a pipe joint structure according to a first embodiment of the present invention, and FIG. 2 is an exploded view thereof. In the pipe joint structure, basically, the male block 10A to which the male pipe 30 is connected and the female block 20A to which the female pipe 40 is connected are concavo-convexly fitted and fastened by a bolt 80.

The male side pipe 30 has an annular flange 31 that bulges in the radial direction, and a protrusion 32 positioned on the distal end side of the flange 31. Further, an annular recess 33 having a substantially V-shaped cross section is engraved on the surface of the collar portion 31 facing the female pipe 40. Further, a chamfer 34 is provided on the inner surface of the tip of the protrusion 32, and the outer peripheral surface of the protrusion 32 is a tapered surface 35 that is tapered toward the end. In this case, the taper angle θ is preferably 3 degrees, for example.
On the other hand, the male block 10A is provided with a through hole 11 for inserting and connecting the male pipe 30 and a pin hole 14 for planting the pin 70 and a bolt hole 15 for inserting the bolt 80. Yes. The majority of the through hole 11 is a hole having an inner diameter substantially the same as the outer diameter of the male side pipe 30, and a large inner diameter first recess in which the packing 60 is seated on the female side block 20 </ b> A side of the through hole 11. 12 and a step concave portion formed of a second concave portion 13 having an inner diameter slightly smaller than the first concave portion 12 on which the flange portion 31 of the male pipe 30 is seated are formed in an enlarged diameter.
Thus, the male side pipe 30 is inserted into the through hole 11 and connected to the male side block 10A by pressure bonding. In this case, the protruding portion 32 of the male side pipe 30 protrudes from the surface facing the female side block 20A of the male side block 10A to become a plug portion of the male side block 10A.

The female side pipe 40 is formed with an enlarged diameter part 41 for fitting a protruding part 32 of the male side pipe 30 and a seal member 50 to be described later at the end thereof. An annular convex portion 42 having a mountain-shaped cross section is formed. In addition, the inner peripheral surface of the enlarged diameter portion 41 is a tapered surface 43 that is tapered forward. In this case, the taper angle θ is preferably 3 degrees, for example.
On the other hand, in the female block 20A, similarly to the male block 10A, the through hole 22 for inserting and connecting the female pipe 40, the pin hole 24 for inserting the pin 70, and the screw for screwing the bolt 80 are inserted. A hole 25 is formed. The substantially half length of the through hole 22 is a hole having an inner diameter substantially the same as the outer diameter of the female side pipe 40, and the remaining length part is for seating the enlarged diameter portion 41 of the female side pipe 40. In addition, a circular recess 21 having a large inner diameter is formed.
Thus, the female side pipe 40 is inserted into the through hole 22 of the female side block 20A and connected to the female side block 20A by pressure bonding. In this case, the enlarged diameter portion 41 of the female side pipe 40 functions as a socket portion of the female side block 20A into which the protruding portion 32 that is the plug portion of the male side block 10A is fitted.

  As block materials for the male side block 10A and the female side block 20A, for example, 7000 series aluminum materials are used, and for the male side pipe 30 and female side piping 40, for example, 3000 series aluminum materials are used. Is done. In this case, the material of the aluminum material becomes softer as the number decreases, and conversely, the material of the aluminum material becomes harder as the number increases. The flange portion 31 and the protruding portion 32 of the male side pipe 30 and the enlarged diameter portion 41 of the female side pipe 40 are formed by pressing a straight pipe, and in the process of pressing, the male side block 10A and the male side pipe 30 and the female side block 20A and the female side pipe 40 are fixed by pressure bonding. Therefore, it is not necessary to perform other fixing methods such as brazing.

  FIG. 3 is a cross-sectional view of the seal member 50 inserted between the male side pipe 30 and the female side pipe 40. The seal member 50 includes a cylindrical skirt portion 51 that extends in the axial direction, a ring-shaped flange portion 52 that extends in the radial direction, and a ring-shaped claw portion that extends downward from the lower surface of the front end of the flange portion 52. 53. Note that the claw portion 53 does not necessarily have a ring shape, and a plurality of claw portions 53 may be provided at intervals in the circumferential direction. In FIG. 3, the skirt portion 51 is tapered so that the taper angle is 3 degrees, but it may be a straight cylindrical shape. That is, the seal member 50 is made of, for example, a 1000 series soft aluminum material, and even if the skirt portion 51 of the seal member 50 is a straight cylindrical shape before mounting, It is because it is pinched by the taper surface 35 of the protrusion part 32 and the taper surface 43 of the enlarged diameter part 41 of the female side piping 40, and deform | transforms into a taper shape.

The packing 60 is made of a rubber material such as EPDM, a resin material, a highly elastic material such as an elastomer, and is formed in a ring shape having a square cross section.
The pin 70 is formed of, for example, stainless steel (SUS), and is implanted in the pin hole 14 of the male block 10A so that a part thereof protrudes from the male block 10A, and is fixed by caulking. Therefore, the pin 70 functions as a positioning convex portion of the male block 10A, and the pin hole 24 of the female block 20A functions as a positioning concave portion. If the diameter of the pin 70 is, for example, about 1 to 5 mm, the strength can be secured. In this case, the protrusion height h from the flat surface of the male block 10A of the protrusion 32, which is the plug portion of the male block 10A, is the protrusion from the flat surface of the male block 10A of the pin 70, which is a positioning convex portion. Each protrusion height is determined so as to be lower than the height H (h <H). Moreover, it is preferable that the positioning convex part and the concave part are formed in each of the blocks 10 </ b> A and 10 </ b> B so as to be positioned on the side opposite to the bolt 80 with respect to the pipes 30 and 40.

  The pipe joint structure which has each component comprised as mentioned above is assembled | attached as follows. First, the seal member 50 is inserted into the protruding portion 32 that is the plug portion of the male block 10A to which the male piping 30 is fixed. At this time, the claw portion 53 of the seal member 50 grips the flange portion 31 of the male side pipe 30. Moreover, the pin 60 is planted in the pin hole 14 of the male block 10A. Further, the packing 60 is attached to the first recess 12 of the male block 10A.

  Next, the positioning convex portion (pin) 60 of the male block 10A is aligned with the positioning concave portion (pin hole) 24 of the female block 20A, and the plug portion (protrusion) in which the seal member 50 of the male block 10A is mounted. Part) 32 and the socket part (expanded diameter part) 41 of the female block 20A, the positioning convex part 60 and the positioning concave part 24 are concavo-convexly fitted. Next, the male block 10A and the female block 20A are firmly fastened by the bolt 80. At this time, since the seal member 50 is made of a material softer than the male and female pipes 30 and 40, the annular convex portion 42 at the tip of the female pipe 40 is formed on the surface of the flange portion 52 of the seal member 50. While biting in, the back surface of the flange portion 52 of the seal member 50 is partially deformed and enters the annular recess 33 of the flange portion 31 of the male pipe 30. As a result, the sealing force is improved.

The pipe joint structure of the present embodiment having the above-described configuration has the following operational effects.
Since the seal member 50 has the skirt portion 51, even if the blocks 10A and 20A are inclined, the skirt portion 51 can be prevented from hitting the pipes 30 and 40 integrated with the blocks 10A and 20A, and the seal member 50 can be prevented from floating. . In addition, since the seal member 50 is softer than the blocks 10A and 20A and the pipes 30 and 40, both blocks are fitted even if the gaps between the blocks and the pipes and the seal member 50 are reduced by closing the tolerances of the respective parts. It is possible. Furthermore, since the seal member 50 has the skirt portion 51 and the plug portion and the socket portion are tapered, the attachment and detachability of the seal member 50 can be improved.
Further, since the male block 10A is provided with a positioning convex portion and the female block 20A is provided with a positioning concave portion, it is easy to position both blocks at the time of concave / convex fitting, and helps to prevent the block from being lifted by refrigerant pressure. It is also. In this case, by making the projection height H of the positioning convex portion higher than the projection height h of the plug portion, the positioning can be performed by the positioning convex portion before the plug portion hits the seal surface of the socket portion when the concave and convex portions are fitted. Therefore, it is possible to prevent the seal part on the socket part side from being damaged.

  FIG. 4 is an exploded view of the pipe joint structure according to the second embodiment of the present invention. In the first embodiment, the positioning convex portion of the male block 10A is formed by the pin 70 which is a separate part. However, in the second embodiment, the positioning convex portion 17 is integrated with the male block 10A. Forming. Even in this case, naturally, the projection height H of the positioning convex portion 17 is preferably higher than the projection height h of the plug portion 32 of the male block 10A. Other configurations including the seal member 50 and the packing 60 that are not illustrated in FIG. 4 are the same as those in the first embodiment, and thus the description thereof is omitted.

  As described above, in the second embodiment, since the positioning convex portion 17 is formed integrally with the male block 10A, the number of parts can be reduced, the assembly cost can be reduced, and the cost can be reduced.

  FIG. 5 is a cross-sectional view of the pipe joint structure of the third embodiment. In the first and second embodiments, the plug portion (projecting portion 32) of the male block 10A and the socket portion (expanded portion 41) of the female block 20A are formed by the male pipe 30 and the female pipe 40, respectively. However, in the third embodiment, these plug part and socket part are formed integrally with the male block 10B and the female block 20B, respectively. Therefore, the straight pipe 90 is only connected to each block 10B, 20B by brazing or the like.

  A projecting portion 16 projecting slightly in a frustoconical shape is formed at a substantially central portion of the male block 10B, and a penetrating refrigerant passage that passes through the center of the projecting portion 16 and penetrates the male block 10B. A hole 11 is formed. The diameter of the through hole 11 matches the inner diameter of the pipe 90. Further, the male block 10B has a bolt hole 15 through which the bolt 80 is inserted on one side across the through hole 11, and a pin hole 14 in which a pin (positioning convex portion) 70 is implanted on the other side. Is formed. The circumferential surface of the protrusion 16 is a tapered surface having a taper angle θ. Further, a U-shaped groove 18 in which the packing 60 is mounted is formed in an annular shape so as to surround the periphery of the protruding portion 16 on the surface of the male block 10B facing the female block 20B. Further, a small annular V-shaped groove is formed inside the annular U-shaped groove 18. Therefore, in the third embodiment, the protruding portion 16 corresponds to the plug portion of the male block 10B.

  On the other hand, a through hole 22 whose position and diameter coincide with the through hole 11 of the male block 10B is also formed in a substantially central portion of the female block 20B. The portion of the through hole 22 on the male block 10B side is A stepped recess 21 is formed for receiving the protruding portion 16 on which the seal member 50 having the skirt portion 51 and the flange portion 52 is mounted. The stepped concave portion 21 includes an inverted frustum-shaped portion 21a on which the skirt portion 51 is seated and a shelf portion 21b on which the flange portion 52 is seated, and an annular convex portion 21c having a mountain-shaped cross section is formed on the shelf portion 21b. . The inner peripheral surface of the inverted frustum-shaped portion 21a is a tapered surface having a taper angle θ. Further, the female block 20B has a screw hole 25 into which a bolt 80 is screwed on one side across the through hole 22, and a pin hole (positioning recess) 24 into which a pin 70 is inserted on the other side. Is formed. Therefore, in the third embodiment, the recess 21 corresponds to the socket portion of the female block 20A.

Since the shapes and materials of the seal member 50, the packing 60, the pins 70, and the like are the same as those in the first embodiment, description thereof is omitted.
The male block 10B and the female block 20B configured as described above have a plug member (protrusion 16) and a socket member in the same manner as described above with the seal member 50 and the packing 60 interposed therebetween. The concave portion 21 is fitted to the concave and convex portions, and the positioning convex portion (pin 70) and the positioning concave portion (pin hole 24) are also fitted to the concave and convex portions, and both blocks 10B and 20B are fastened by the bolt 80.

Instead of the pin 70 of the third embodiment, the positioning convex portion 17 formed integrally with the male block 10A of the second embodiment may be used.
In the first to third embodiments, the bolt 80, the positioning convex portions 70 and 17 and the concave portion 24 are disposed at symmetrical positions passing through the center of the block with respect to the refrigerant passage. You may arrange | position a convex part and a recessed part in the position shifted | deviated from the block center. This also makes it possible to arrange the piping laterally from the block.

It is sectional drawing of the pipe joint structure of 1st Embodiment of this invention. It is an exploded view of the pipe joint structure of a 1st embodiment. It is sectional drawing of a sealing member. It is an exploded view of the pipe joint structure of 2nd Embodiment of this invention. It is sectional drawing of the pipe joint structure of 3rd Embodiment of this invention.

Explanation of symbols

10A, 10B Male side block 11 Through hole 12 1st recessed part 13 2nd recessed part 16 Protrusion part (plug part)
17 Positioning convex part 20A, 20B Female side block 21 Stepped concave part (socket part)
30 Male side piping 31 Gutter part 32 Projection part (plug part)
40 Female piping 41 Expanded diameter part (socket part)
50 Seal member 51 Skirt part 52 Flange part 53 Claw part 60 Packing 70 Pin (positioning convex part)
80 volts

Claims (14)

The male side block (10A, 10B) to which the male side pipe (30) is connected and the female side block (20A, 20B) to which the female side pipe (40) is connected include the seal member (50) and the packing. In a pipe joint structure in which concave and convex fitting is performed so as to sandwich (60) between both blocks (10A, 20A; 10B, 20B) and both blocks are fastened by bolts (80).
The seal member (50) has a skirt portion (51) extending in a cylindrical shape or a tapered cylindrical shape in the axial direction and a flange portion (52) extending in an annular shape in the radial direction, and the male member The plugs (32, 16) are provided on the side blocks (10A, 10B), and the sockets (41, 21) are provided on the female side blocks (20A, 20B). A pipe joint structure in which an axial direction and a radial direction are sealed by interposing the seal member between a portion and a socket portion.   The plug part (32, 16) of the male block (10A, 10B) is tapered slightly in a tapered shape, and the socket part (41, 21) of the female block (20A, 20B) is formed. The taper is formed so that the diameter is slightly increased toward the tip, and the skirt part (51) of the seal member (50) interposed between the plug part and the socket part is similarly tapered. The pipe joint structure according to claim 1, wherein the pipe joint structure is formed.   3. The pipe joint structure according to claim 2, wherein the three taper angles θ of the plug portion, the socket portion, and the skirt portion of the seal member are substantially the same. The male side block (10A, 10B) to which the male side pipe (30) is connected and the female side block (20A, 20B) to which the female side pipe (40) is connected include the seal member (50) and the packing. (60) is a concave and convex fit so as to be sandwiched between both blocks, and both blocks are fastened by bolts (80),
One male side block is provided with plug portions (32, 16) and positioning convex portions (70, 17), and the other female side block is provided with socket portions (41, 21) and positioning portions. A pipe joint structure provided with a concave portion (24), wherein the plug portion, the socket portion, the positioning convex portion, and the positioning concave portion are respectively engaged with each other.   The concave / convex fitting position between the positioning convex portion and the positioning concave portion is located on the opposite side of the bolt with respect to the concave / convex fitting position between the plug portion and the socket portion. Item 5. The pipe joint structure according to Item 4.   The pipe joint structure according to claim 4 or 5, wherein a projection height H of the positioning convex portion is higher than a projection height h of the plug portion.   The pipe joint structure according to claim 4, 5 or 6, wherein the positioning convex portion is a pin (70) implanted in the male block.   The pipe joint structure according to any one of claims 4 to 7, wherein the positioning convex part (17) is formed integrally with the male block.   The plug part of the male block is a protruding part (32) of the male pipe (30) connected to the male block, and the socket part of the female block is connected to the female block The pipe joint structure according to any one of claims 1 to 8, wherein the pipe joint structure is an enlarged-diameter portion (41) of the female pipe (40) to be provided.   The plug portion of the male block is a protrusion (16) formed integrally with the male block (10B), and the socket portion of the female block is formed on the female block (20B). The pipe joint structure according to any one of claims 1 to 8, wherein the pipe joint structure is a recessed portion (21).   11. The pipe joint structure according to claim 1, wherein the packing 60 is disposed on an outer periphery of the seal member 50.   The pipe joint structure according to claim 11, wherein the packing 60 is made of a material having higher elasticity than a metal material such as rubber, resin, or elastomer.   The pipe joint structure according to claim 11, wherein a material of the packing is EPDM.   The pipe joint structure according to claim 11, wherein the packing has a quadrangular cross-sectional shape.

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