JP2009063073A - Joint for piping - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint for piping in a refrigerating cycle, capable of improving workability in separating a male side joint member from a female side joint member. <P>SOLUTION: The joint for piping is provided with the male side joint member 11 having a cylindrical engagement projection 12, and the female side joint member 13 having an engagement recess 14 in which the engagement projection 12 of the male side joint member 11 is fitted. On a tip part of the engagement projection 12 of the male side joint member 11, a small diameter part 18 for installing an O-ring is formed, and a first O-ring 15A is disposed around the small diameter part 18. On an outer circumferential surface of a large diameter part 19 in the engagement projection 12 of the male side joint member 11 except the small diameter part 18, a circular groove 21 for installing a single O-ring is formed along the whole circumference, and a second O-ring 15B is disposed in the circular groove 21. With distance A mm from a base end of the engagement projection 12 in the male side joint member 11 to the circular groove 21, and cross sectional diameter B mm of the first O-ring 15A disposed on the small diameter part 18, a relation of A≥B is satisfied. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a pipe joint for piping through which, for example, a high-pressure fluid flows. More specifically, the present invention relates to a compressor, a gas cooler, an evaporator, a decompressor, a gas-liquid separator, and a refrigerant coming out of an evaporator In a supercritical refrigeration cycle in which an intermediate heat exchanger for exchanging heat is connected by piping and a supercritical refrigerant such as CO ₂ (carbon dioxide) is used, connection between piping for piping and various devices, and / or Or it is related with the coupling for piping used suitably for the connection of the pipes for piping.

  In this specification, the “supercritical refrigeration cycle” means a refrigeration cycle in which the refrigerant reaches a supercritical state exceeding the critical pressure on the high-pressure side, and the “supercritical refrigerant” means the supercritical refrigeration cycle. It shall mean the refrigerant used in

  Conventionally, for example, a male joint member having a cylindrical fitting convex portion as a pipe joint used for connection between pipes and various devices in a supercritical refrigeration cycle and / or connection between pipes; A female joint member having a fitting recess into which the entire fitting convex portion of the male joint member fits, and an outer peripheral surface of the fitting convex portion arranged at intervals in the length direction and fitted with the fitting convex portion. It has two O-rings that seal between the joint recesses, and the fitting convex part has a large diameter part provided on the proximal end side and a small diameter part provided on the distal end side, and is fitted The recess has a large-diameter portion into which the large-diameter portion of the fitting convex portion fits and a small-diameter portion into which the small-diameter portion of the fitting convex portion fits, and O-rings on the peripheral surfaces of the large-diameter portion and small-diameter portion of the fitting convex portion, respectively. An annular groove for mounting is formed, and an O-ring is disposed in each annular groove (see Patent Document 1).

Meanwhile, O-ring butadiene acrylonitrile rubber (NBR), hydrogenated butadiene acrylonitrile rubber (HNBR), ethylene propylene rubber (EPDM), are formed by a rubber such as fluorine rubber (FKM), CO ₂ is these rubber since transmission, when the pipe joint described in Patent Document 1, together with CO ₂ is present between the two O-rings during operation of a supercritical refrigeration cycle, so that the CO ₂ is introduced into an interior of the two O-ring.

Therefore, in the case of the joint for piping described in Patent Document 1, when the male joint member and the female joint member are separated after stopping the supercritical refrigeration cycle and removing CO ₂ , the small diameter of the fitting convex portion When the O-ring disposed in the annular groove for mounting the O-ring formed in the portion reaches the large diameter portion of the fitting recess of the female joint member, the CO ₂ entering the O-ring Swells and contacts the inner peripheral surface of the large-diameter portion of the fitting concave portion, so that the fitting convex portion comes out of the fitting concave portion while the two O-rings are in sliding contact with the inner peripheral surface of the large-diameter portion thereafter. Thus, there is a problem that workability when separating the male joint member and the female joint member of the joint for piping is lowered.
JP 2007-107585 A

  An object of the present invention is to provide a pipe joint for a refrigeration cycle that solves the above problems and can improve workability when separating a male side joint member and a female side joint member.

  In order to achieve the above object, the present invention comprises the following aspects.

1) A male joint member having a cylindrical fitting convex part, a female joint member having a fitting concave part into which the fitting convex part of the male joint member fits, and an outer peripheral surface of the fitting convex part. A joint for piping comprising an O-ring that is arranged at intervals in the direction and seals between the fitting convex part and the fitting concave part,
A small-diameter portion for mounting an O-ring is formed at the tip of the fitting convex portion of the male joint member, an O-ring is disposed around the small-diameter portion, and the small-diameter portion of the fitting convex portion of the male joint member is excluded. An annular groove for mounting an O-ring is formed on the outer peripheral surface of the large-diameter portion, and the O-ring is disposed in the annular groove. The distance from the base end of the fitting convex portion in the male joint member to the annular groove is set. A joint for piping satisfying the relationship of A ≧ B, where Amm and the cross-sectional diameter of the O-ring disposed in the small diameter portion is Bmm.

  2) The pipe joint according to 1) above, wherein the small diameter portion for mounting the ring-shaped seal member has a tapered shape with a diameter reduced toward the tip, and the taper angle of the small diameter portion is 2 to 10 degrees.

  3) The pipe joint according to 1) or 2) above, wherein a refrigerant flow path is formed in the male joint member, and the inside of the fitting convex portion of the male joint member communicates with the refrigerant flow path.

  4) The piping joint according to 1) or 2) above, wherein the fitting convex portion is a tip of a piping pipe penetrated by the male joint member.

  5) The piping joint according to any one of the above 1) to 4), wherein a refrigerant channel is formed in the female joint member, and a fitting recess of the female joint member communicates with the refrigerant channel.

According to the joint for piping of 1) above, a small-diameter portion for mounting an O-ring is formed at the distal end portion of the fitting convex portion of the male-side joint member, and an O-ring is disposed around the small-diameter portion. An annular groove for mounting an O-ring is formed over the entire circumference on the outer peripheral surface of the large-diameter portion excluding the small-diameter portion of the fitting convex portion, and the O-ring is disposed in the annular groove. When the distance from the base end of the portion to the annular groove is Amm and the cross-sectional diameter of the O-ring disposed in the small diameter portion is Bmm, the relationship of A ≧ B is satisfied. When used in a supercritical refrigeration cycle using CO ₂ as a refrigerant, during operation of the supercritical refrigeration cycle, an O-ring disposed in a small diameter portion for mounting an O-ring, an O-ring disposed in an annular groove, CO ₂ is present between each and within each O-ring This means that CO ₂ has infiltrated. Then, after the supercritical refrigeration cycle is stopped and the CO ₂ is removed, when the male joint member and the female joint member are separated, the O-ring arranged around the small diameter portion is in the O-ring. Even if the O-ring swelled by the invading CO _2, the O-ring arranged around the small-diameter portion is caused by the pressure of CO ₂ remaining between the O-ring and the O-ring arranged in the annular groove. Pressed toward the distal end side of the small diameter portion and detached from the small diameter portion. Therefore, the O-ring arranged in the small diameter portion does not slide in contact with the inner peripheral surface of the fitting recess until the fitting projection is completely removed from the fitting recess thereafter. Compared with the joint for use, the workability when separating the male joint member and the female joint member is improved. Moreover, when the O-ring arranged in the small-diameter portion is detached from the small-diameter portion, the O-ring arranged in the annular groove is formed between the fitting convex portion of the male joint member and the fitting concave portion of the female joint member. Since the gap is sealed, the refrigerant remaining between these two O-rings will flow into the piping pipe or various equipment side where the female joint member is provided, preventing escape to the atmosphere. Is done.

  According to the piping joint of 2) above, since the small diameter portion for mounting the O-ring has a tapered shape with the diameter reduced toward the tip, and the taper angle of the small diameter portion is 2 to 10 degrees, the male joint member When separating the female-side joint member, the O-ring arranged around the small-diameter portion can be more easily detached.

  Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the pipe joint according to the present invention is applied to connection between pipes of a supercritical refrigeration cycle.

  In the following description, the term “aluminum” includes aluminum alloys in addition to pure aluminum. In the following description, the top and bottom and the left and right in FIGS.

Embodiment 1
This embodiment is shown in FIGS.

  FIG. 1 shows a supercritical refrigeration cycle, FIGS. 2 and 3 show the overall configuration of a joint for piping, and FIGS. 4 and 5 show the configuration of the main part thereof.

In FIG. 1, the supercritical refrigeration cycle uses a supercritical refrigerant such as CO _2, and includes a compressor (1), a gas cooler (2), an evaporator (3), and an accumulator as a gas-liquid separator ( 4) an expansion valve (5) as a decompressor, and an intermediate heat exchanger that exchanges heat between the refrigerant coming out of the gas cooler (2) and the refrigerant coming out of the evaporator (3) and passing through the accumulator (4) ( 6) is connected by piping (7), and the piping pipe and various equipment for the supercritical refrigeration cycle and / or piping pipes constituting the piping (7) are connected by a piping joint. ing. Here, the various devices for the supercritical refrigeration cycle are a compressor (1), a gas cooler (2), an evaporator (3), an accumulator (4), an expansion valve (5), and an intermediate heat exchanger (6). This supercritical refrigeration cycle is mounted on a vehicle such as an automobile as a car air conditioner, for example. As the supercritical refrigerant, ethylene, ethane, nitrogen oxide, or the like can be used instead of CO ₂ .

  2 and 3, the pipe joint (10) for connecting the pipes (P1) and (P2) to each other includes a male joint member (11) having a cylindrical fitting projection (12) and an inner joint member (11). A female joint member (13) having a fitting concave portion (14) in which a peripheral surface is a cylindrical surface and a fitting convex portion (12) of the male joint member (11) is fitted; and a male joint member (11) Two O-rings (15A) and (15B) are provided for sealing between the outer peripheral surface of the fitting convex portion (12) and the inner peripheral surface of the fitting concave portion (14) of the female joint member (13).

  The male joint member (11) is formed of a metal, here aluminum, and has a block shape that is long in the vertical direction, extends in the left-right direction at the lower end portion thereof, and has a penetrating refrigerant flow path (inner peripheral surface is a cylindrical surface) 16) is formed. The left and right side surfaces of the male joint member (11) are flat surfaces, and the fitting convex portion (12) is around the right end opening of the refrigerant flow path (16) on the right side surface of the male side joint member (11). Are integrally formed in a rightward protruding shape. The refrigerant flow path (16) extends to the front end surface of the fitting convex part (12). In addition, the end of the pipe (P1) made of metal, here aluminum, is inserted into the left end of the refrigerant flow path (16) of the male joint member (11), and the male joint member (11) It is joined. A through hole (17) extending in the left-right direction is formed at the upper end of the male joint member (11).

  A small-diameter portion (18) for mounting an O-ring is formed at the tip of the fitting convex portion (12) of the male side coupling member (11). The small diameter portion (18) has a tapered shape with a diameter reduced toward the tip, and the taper angle (X) of the small diameter portion (18) is preferably 2 to 10 degrees. In addition, one annular groove (21) for mounting an O-ring is formed on the entire outer periphery of the large-diameter portion (19) excluding the small-diameter portion (18) in the fitting convex portion (12). The outer diameter of the large diameter portion (19) is the same over the entire length. Around the small-diameter part (18), the O-ring (15A) with a circular cross section and the backup ring (22) so that the O-ring (15A) comes to the front end side (right end side) of the fitting convex part (12) Is arranged. An O-ring (15B) is disposed in the annular groove (21). Hereinafter, the O-ring (15A) disposed around the small diameter portion (18) is referred to as a first O-ring, and the O-ring (15B) disposed in the annular groove (21) is referred to as a second O-ring. . Each O-ring (15A) (15B) is formed of, for example, HNBR, NBR, EPDM, FKM or the like.

  Here, the distance from the base end (left end) of the fitting convex portion (12) in the male side joint member (11) to the left side surface of the annular groove (21) is Amm, and the cross-sectional diameter of the first O-ring (15A) When (the diameter of the cross section before being arranged in the small diameter portion (18)) is Bmm, the relationship of A ≧ B is satisfied (see FIGS. 4 and 5).

  The female joint member (13) is formed of a metal, here aluminum, and has a vertically long block shape, and a penetrating refrigerant flow path (23) extending in the left-right direction at the lower end thereof is a male joint member ( It is formed so as to coincide with the refrigerant flow path (16) of 11). The left and right side surfaces of the female joint member (13) are flat surfaces, and the fitting recess (14) is formed to open to the left side surface of the female side joint member (13). The inner diameter of the fitting recess (14) is the same over the entire length. The left end of the refrigerant channel (23) is open to the bottom surface of the fitting recess (14). In addition, the end of the pipe (P2) made of metal, here aluminum, is inserted into the right end of the refrigerant flow path (23) of the female joint member (13) and joined to the female joint member (13). Has been. A penetrating female screw hole (24) extending in the left-right direction is formed at the upper end of the female joint member (13) so as to match the through hole (17) of the male joint member (11).

  The male joint member (11) and the female joint member (13) are configured so that the fitting convex part (12) of the male joint member (11) is in the fitting concave part (14) of the female joint member (13). In the fitted state, the bolts (25) passed through the through holes (17) of the male joint member (11) are screwed into the female screw holes (24) of the female joint member (13). They are connected to form a pipe joint (10), whereby both pipes (P1) and (P2) are connected via the pipe joint (10).

In the pipe joint (10) described above, the separation work of the male joint member (11) and the female joint member (13) after stopping the supercritical refrigeration cycle and removing CO ₂ is as follows. Done.

First, after removing the bolt (25), the joint members (11) and (13) are moved away from each other. Then, as shown in FIG. 5, the distance between the tip of the fitting convex portion (12) of the male joint member (11) and the bottom of the fitting concave portion (14) of the female joint member (13) is When the cross-sectional diameter of the O-ring (15A) is 1 mm or more, the distance from the base end (left end) of the fitting projection (12) to the left side of the annular groove (21) in the male joint member (11) is Amm. When the cross-sectional diameter of the first O-ring (15A) is Bmm, the relationship of A ≧ B is satisfied, so that the CO ₂ pressure remaining between the O-rings (15A) and (15B) The first O-ring (15A) is pressed toward the distal end of the small diameter portion (18), and the small diameter portion (18) is tapered toward the distal end, and the taper angle is 2 to 10 degrees. In combination with this, it is easily removed from the small diameter part (18). Moreover, even after the first O-ring (15A) is disengaged from the small-diameter portion (18), the second O-ring (15B) is fitted to the fitting convex portion (12) of the male side joint member (11) and the female side joint. Since the gap between the fitting recess (14) of the member (13) is sealed, the CO ₂ remaining between the O-rings (15A) and (15B) flows into the refrigerant flow of the female joint member (13). It flows into the pipe (P2) on the right side through the path (23), and as a result, escape to the atmosphere is prevented.

  After that, when the joint members (11) and (13) are further moved away from each other, only the second O-ring (15B) is brought into sliding contact with the inner peripheral surface of the fitting recess (14). The convex part (12) comes out of the fitting concave part (14). Thus, the male joint member (11) and the female joint member (13) are separated.

Embodiment 2
This embodiment is shown in FIGS.

  In the case of the pipe joint (40) of Embodiment 2, a circular through hole (42) extending in the left-right direction is formed at the lower end of the male joint member (41), and the pipe is connected to the through hole (42) from the left side. The pipe (P3) is passed and the right end of the pipe (P3) is protruded to the right of the male joint member (41). And the fitting convex part (43) where the tip part projected rightward from the male side joint member (41) of the pipe for piping (P3) fits in the fitting concave part (14) of the female side joint member (13) It has become. A small-diameter portion (18) for mounting an O-ring is formed at the tip of the fitting convex portion (43). In addition, one annular groove (21) for mounting an O-ring is formed on the entire outer periphery of the large-diameter portion (19) excluding the small-diameter portion (18) in the fitting convex portion (43).

  Also in the second embodiment, the distance from the base end (left end) of the fitting convex portion (43) of the male joint member (41) to the left side surface of the annular groove (21) is Amm, and the first O-ring (15A ) Satisfies the relationship of A ≧ B.

  A large-diameter portion (45) is formed at the right end of the through hole (42) of the male joint member (41) via a step portion (44), and the pipe portion (P3) has a step portion (44 ) Is formed. Further, an annular recess (47) is formed over the entire circumference on the inner peripheral surface of the left end of the through hole (42) of the male joint member (41), and a part of the pipe for piping (P3) is expanded to The expanded pipe portion (48) is press-fitted into the annular recess (47). Then, since the annular bead (46) is engaged with the stepped portion (44) and the expanded pipe portion (48) is press-fitted into the annular recess (47), both joint members (41) ( Even in the state before 13) is connected with the bolt (25), the male joint member (41) and the pipe for piping (P3) do not relatively move in the left-right direction.

  Other configurations are the same as those of the pipe joint (10) of the first embodiment, and the same components and the same parts are denoted by the same reference numerals.

  In the above two embodiments, the pipe joints (10) and (40) of the present invention are used to connect the pipes (P1), (P2), and (P3) that make up the pipe (7) of the supercritical refrigeration cycle. Although it is used, the present invention is not limited to this, and the piping joint (10) (40) of the present invention is a piping pipe (P1) (P2) constituting the piping (7) of the supercritical refrigeration cycle. (P3) and connection with at least one of compressor (1), gas cooler (2), evaporator (3), accumulator (4), expansion valve (5) and intermediate heat exchanger (6) Sometimes used. In this case, one of the male joint members (11) and (41) and the female joint member (13) is directly attached to the device.

  In the above two embodiments, the pipe joint (10) of the present invention is used for connecting pipes (P1), (P2), (P3) and various devices in the supercritical refrigeration cycle, and / or for pipes. Used to connect pipes (P1), (P2), and (P3), but is not limited to this. A compressor, a condenser, an evaporator, a gas-liquid separator, and a decompressor are connected by piping. In addition, it may be used for connection between piping pipes and various devices and / or connection between piping pipes in a refrigeration cycle in which a fluorocarbon refrigerant is used. Furthermore, it may be used for connection between pipes and other devices through which other high-pressure fluid flows and / or connection between pipes for piping.

It is a figure which shows the supercritical refrigerating cycle using the coupling for piping of Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the state after the connection which shows the coupling for piping of Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the state before the connection which shows the coupling for piping of Embodiment 1 of this invention. FIG. 3 is a partially enlarged view of FIG. 2. FIG. 5 is a view corresponding to FIG. 4 and showing a stage in the middle of separating the male side joint member and the female side joint member in the pipe joint of FIG. 1. It is a longitudinal cross-sectional view of the state after the connection which shows the coupling for piping of Embodiment 2 of this invention. It is a longitudinal cross-sectional view of the state before the connection which shows the coupling for piping of Embodiment 2 of this invention. It is the elements on larger scale of FIG.

Explanation of symbols

(7): Piping
(10) (40): Fitting for piping
(11) (41): Male joint member
(12) (43): Mating convex part
(13): Female joint member
(14): Fitting recess
(15A) (15B): O-ring
(16): Refrigerant flow path
(18): Small diameter part
(19): Large diameter part
(21): Annular groove
(23): Refrigerant flow path
(P1) (P2) (P3): Pipe for piping

Claims (5)

A male joint member having a cylindrical fitting convex portion, a female joint member having a fitting concave portion into which the fitting convex portion of the male joint member fits, and an outer peripheral surface of the fitting convex portion in the length direction. A joint for piping provided with an O-ring that is arranged at intervals and seals between the fitting convex part and the fitting concave part,
A small-diameter portion for mounting an O-ring is formed at the tip of the fitting convex portion of the male joint member, an O-ring is disposed around the small-diameter portion, and the small-diameter portion of the fitting convex portion of the male joint member is excluded. An annular groove for mounting an O-ring is formed on the outer peripheral surface of the large-diameter portion, and an O-ring is disposed in the annular groove. The distance from the base end of the fitting convex portion in the male joint member to the annular groove is increased. A joint for piping satisfying the relationship of A ≧ B, where Amm and the cross-sectional diameter of the O-ring disposed in the small diameter portion is Bmm. The pipe joint according to claim 1, wherein the small-diameter portion for mounting the O-ring has a tapered shape with a diameter reduced toward the tip, and the taper angle of the small-diameter portion is 2 to 10 degrees. The piping joint according to claim 1 or 2, wherein a refrigerant flow path is formed in the male joint member, and an inside of the fitting convex portion of the male joint member communicates with the refrigerant flow path. The piping joint according to claim 1 or 2, wherein the fitting convex portion is a tip of a piping pipe penetrated by the male joint member. The pipe joint according to any one of claims 1 to 4, wherein a refrigerant channel is formed in the female joint member, and a fitting recess of the female joint member communicates with the refrigerant channel.

Images