JP3939311B2 - Pipe fitting - Google Patents

Description

  The present invention is for connecting pipes for pneumatic equipment and hydraulic equipment, pipes for refrigerant gas filling such as cooling and heating air conditioners, pipes for water facilities such as water supply and hot water supply for houses, etc. It relates to pipe joints.

  For example, when connecting a pipe for refrigerant gas piping to a flare connecting portion provided in an outdoor unit of an air conditioner, conventionally, as shown in FIG. Then, the end portion Pa of the pipe P is formed into a taper shape so as to increase in diameter toward the tip side by flare processing, and the end portion Pa of the pipe P processed into the taper shape is fitted into the flare connection portion 100, and the nut 102 Thus, a method of fixing the tapered end portion Pa so as to be in close contact with the tapered surface 101 of the flare connecting portion 100 has been adopted.

A method of flaring the end portion of the pipe into a tapered shape when connecting the pipe is described in Patent Document 1.
JP-A-6-262541

  The conventional method has a problem that work efficiency at the site is poor because the worker flares the pipe at the connection site. In addition, there is a problem that it is difficult for an unskilled person to set the flare angle of the pipe to an appropriate angle.

  The present invention has been made in view of the above circumstances, and has an object to connect a pipe and a flare connecting portion without subjecting the pipe to flare processing.

The invention of claim 1 has a through hole that can communicate with a fluid flow path, and a pipe connection mechanism that connects a metal pipe constituting the flow path is provided at one end of the through hole. The other end of the through hole is provided with a flare connection mechanism connected to a tapered flare connection part constituting the flow path, and the pipe connection mechanism is made of brass, A tubular joint body that allows insertion of a pipe, a tubular fastening member that is screwed into the joint body, and a tube that is made of copper and surrounds the pipe inserted into the joint body A metal-made fastening ring and a tapered surface inclined with respect to the pipe insertion direction, and the fastening ring is made airtight with respect to the inner periphery of the joint body as the fastening member is screwed. By tightening and plastically deforming in the reduced diameter direction, the clamping ring is State periphery is constituted by a reduced diameter section which is adapted tightened in a form that adheres to the bite and / or air-tight state to the displacement restricting state to, in which the clamping ring in the pipe connecting mechanism is tightened to the normal Then, the clamping ring and the pipe abut at a plurality of locations in the pipe insertion direction, and the clamping ring and the joint main body abut at two locations in the pipe insertion direction. The contact portion is in contact with the surface contact form, and in the other contact portion, the corner edge of the joint body is in contact with the clamping ring so as to bite into the fastening ring . A tapered connecting surface capable of being brought into surface contact with the flare connecting portion; and a locking means capable of holding the tapered connecting surface in a state of being pressed against the flare connecting portion. Characterized in place being.

The invention according to claim 2 is the assembly according to claim 1 , wherein the fastening member and the fastening ring are locked to each other so that the fastening ring is separated from the fastening member. It is characterized in that holding means capable of holding the state is provided.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the tightening member is screwed into the joint body and the tightening member in a direction in which the diameter of the tightening ring is reduced. A pair of contact surfaces approaching with each other is provided, and in the process in which the tightening member is screwed, the pair of contact surfaces remain in non-contact with the tightening ring against the pipe. The tightening member is in a normal tightening state, and the tightening ring is maintained in the normal tightening state while the screw advances to the position where the pair of contact surfaces abut against each other. .
Here, the regular tightening state refers to a state in which an airtight state is maintained so that fluid in the pipe does not leak to the outside, and the pipe is locked so as not to be detached from the pipe connection mechanism.

According to a fourth aspect of the present invention , in the invention described in claim 3, an identification ring may be provided on the joint main body so as to be relatively rotatable, and the contact surface may be formed on the identification ring.
According to the fourth invention , in a state where the contact surfaces do not contact each other, the identification ring can be rotated, and the tightening of the tightening ring to the pipe proceeds until the contact surfaces contact each other, so that the pipe is connected. In the completed state, the identification ring is sandwiched between the tightening member and the joint body, and cannot rotate. Therefore, it can be determined whether or not the pipe connection work has been correctly completed based on whether or not the identification ring can rotate.

Moreover, as 5th invention , in the thing in any one of Claim 1 thru | or 3rd, 4th invention, the insertion outer periphery edge of the said pipe can contact | abut to the inner periphery of the said coupling main body. It is good also as a structure which forms a tapered front stop surface.
According to the fifth invention , the tapered front stop surface formed on the inner periphery of the joint body serves as a stopper for stopping the pipe when the pipe is inserted, and the pipe can be positioned.
In addition, when tightening proceeds, the tightening ring moves in the axial direction of the pipe in accordance with the inclination of the tapered surface of the diameter reducing means while reducing the diameter, but if the pipe abuts its front end surface If it is stopped at the front, frictional resistance is generated between the pipe and the tightening ring, and the tightening torque of the tightening member is increased, which may cause a decrease in workability. However, according to the present invention, the outer peripheral edge of the pipe is brought into contact with the tapered front stop surface, so that the pipe can be moved in the insertion direction together with the tightening ring. The workability can be improved by reducing the frictional resistance between the pipe and the tightening ring.
Further, when the pipe is pushed and moved together with the tightening ring from the state in which the pipe is stopped at the front side along with the fastening ring, the leading edge of the pipe in the insertion direction and the front stop surface are Since they come to bite each other, the return of the pipe is regulated by the frictional resistance caused by this biting, and consequently the tightening member is prevented from loosening.

Further, as a sixth invention , in any one of the first to third, fourth, and fifth inventions, an inclination of the tapered surface on the joint main body side constituting the diameter reducing means. The angle and the inclination angle of the tapered surface on the fastening ring side may be different from each other.
If the inclination angle of the taper surface on the joint body side and the taper surface on the fastening ring side that constitute the diameter reducing means are the same, the time when both taper surfaces come into contact with each other As a result, the frictional resistance suddenly increases. As a result, the clamping ring cannot be displaced relative to the joint body in the axial direction (pipe insertion direction), and the clamping ring cannot be reduced in diameter. Or the tightening ring may buckle.
In contrast, in the sixth aspect of the invention , the inclination angle of the tapered surface on the joint body side and the inclination angle of the tapered surface on the fastening ring side are different from each other. In addition, since the circumferential line contact state occurs, the tendency to increase the frictional resistance is alleviated compared to the surface contact state.
As the contact of the taper surface advances, both contact areas increase. However, since the contact area gradually increases, the frictional resistance tends to increase gradually. The diameter can be reliably reduced and deformed while being relatively displaced in the axial direction with respect to the main body.

According to a seventh aspect of the present invention , in the sixth aspect of the invention, when the tightening ring is in a proper tightening state, the joint body side taper surface constituting the diameter reducing means and the tightening The taper surface on the ring side may be in close contact with each other in a surface contact state.
Here, the regular tightening state refers to a state in which an airtight state is maintained so that fluid in the pipe does not leak to the outside, and the pipe is locked so as not to be detached from the pipe connection mechanism.
According to the seventh invention , in the sixth invention , when the tightening ring is in a normal tightening state, the joint body side taper surface and the tightening ring side taper surface constituting the diameter reducing means are Since they are in close contact with each other, it is difficult for the two tapered surfaces to separate due to the frictional resistance and the biting action generated between the two tapered surfaces, thereby preventing the tightening ring from loosening.

<Invention of Claim 1>
When the pipe is inserted into the joint body and the fastening member is tightened, the fastening ring bites into the pipe by the diameter reducing means, and the pipe is locked in the connected state, and the fastening ring is in an airtight state with respect to the outer periphery of the pipe. And the fastening ring closely contacts the inner periphery of the joint body, thereby sealing between the joint body and the pipe. When connecting the pipe, it is not necessary to flare the pipe because the pipe is simply inserted into the joint body and tightened by the tightening ring. And if it locks in the state which pressed the taper-shaped connection surface against the flare connection part by the locking means, the pipe connected to the pipe connection mechanism will be connected to the flare connection part.

In addition, since the tightening ring comes into contact with the inner periphery of the joint main body at two locations and the tightening ring is tightened with respect to the pipe at a plurality of locations, the reliability of the lock and the seal is excellent.

< Invention of Claim 2 >
Prior to inserting the pipe, the tightening member is assembled in a state where it is screwed into the joint body in a shallow state.However, the tightening ring is fastened to the tightening member by engaging the tightening member and the tightening ring. On the other hand, since the holding means for holding it in the assembled state is provided, by assembling the tightening ring to the tightening member, both are unitized, and the entire assembling work becomes easy.

< Invention of Claim 3 >
From the position where the tightening ring is properly tightened with respect to the pipe, the tightening ring is in the proper tightening state until the pair of contact surfaces are brought into contact with each other by further screwing the tightening member. Because it keeps, the tightening of the tightening ring to the pipe will not loosen. Therefore, when connecting the pipes, it is easy and reliable to visually check whether the work is completed or not by establishing a work manual for screwing the tightening member to a position where the pair of contact surfaces abut against each other. Can be determined.

<Embodiment 1>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. The pipe joint Ja according to the present embodiment is a copper pipe P used for piping as a fluid flow path in a fluid pressure operating device such as a pneumatic device or a hydraulic device, and is used for various devices (for example, an outdoor unit of an air conditioner). This is for connection to the flare connection M. The metal pipe P can also be applied to pipes used for refrigerant gas filling, such as cold air conditioners, and pipes for water facilities such as water supply / hot water supply for houses. Further, the pipe joint Ja according to the present embodiment is used for piping on the assumption that the pipe P is not removed from the pipe joint Ja after the pipe P is once connected.

  The pipe joint Ja has a through hole 15 penetrating in the front-rear direction, and a pipe connection mechanism Ca is provided at the left end of the through hole 15 in FIG. 1, and at the right end of the through hole 15 in FIG. A flare connection mechanism Cb is provided. In the following description, the right side in FIG. Moreover, the front-rear direction and the axial direction parallel to the axis of the pipe joint Ja are used synonymously. Furthermore, the insertion direction (connection direction) of the pipe P with respect to the pipe joint Ja is parallel to the front-rear direction.

The pipe connection mechanism Ca includes a metal joint body 10, a metal tightening member 20, and two metal front and rear tightening rings 30 and 40.
The joint body 10 is made of brass and has a cylindrical shape as a whole. A male screw portion 11 for screwing the fastening member 20 is formed on the outer periphery of the rear end portion of the joint main body 10, and a regular hexagonal jig is formed at a position in front of the male screw portion 11 on the outer periphery of the joint main body 10. A tool fitting portion 12 is formed. A flat contact surface 13 that is orthogonal to the axial direction is formed on the rear end surface of the jig fitting portion 12.

  The hollow inside of the joint body 10 is a circular through-hole 15 that is open at both front and rear end faces of the joint body 10 (through the joint body 10 in the front-rear direction). The rear end portion of the through hole 15 is a circular connection hole 16 having the same diameter as or slightly larger than the outer diameter of the pipe P. The front end of the pipe P is inserted into the connection hole 16 from the rear. A stopper 17 is formed at the front end of the connection hole 16 to reduce the diameter in a step shape.

  The inner peripheral surface of the front end side portion of the connection hole 16 is a front tapered surface 16a (a front stop surface which is a constituent feature of the present invention) that decreases in diameter toward the front, and the rear tapered surface 16a has a rear surface. The inner diameter of the end (the maximum inner diameter of the front tapered surface 16a) is slightly larger than the outer diameter of the pipe P, and the inner diameter of the front end of the front tapered surface 16a (the minimum inner diameter of the front tapered surface 16a) is the outer diameter of the pipe P. Is set to be slightly smaller. The inner peripheral surface of the central portion of the connection hole 16 is a constant diameter surface 16b having a constant diameter from the front end to the rear end. The inner peripheral surface of the rear end side portion of the connection hole 16 is a rear tapered surface 16c (diameter reducing means that is a constituent element of the present invention) that increases in diameter toward the rear. Furthermore, the rear end surface of the joint body 10 is formed with a flat surface 10a perpendicular to the insertion / extraction direction of the pipe P (= the screwing direction of the tightening member 20 and the moving direction associated with the tightening of the tightening rings 30 and 40). In addition, the inner peripheral edge of the flat surface 10a, that is, the peripheral edge serving as a boundary with the rear taper surface 16c is an edge-shaped angular edge 10b.

  The fastening member 20 is made of brass, and is assembled to the joint body 10 by screwing an internal thread part 21 of the inner periphery thereof to the male thread part 11 of the joint body 10. Further, an inward projection 23 that protrudes inward in a circular shape concentric with the tightening member 20 is formed at the rear end of the tightening member 20 as a holding means. A tapered guide surface 24 is formed on the inner periphery of the front end surface. Further, an escape hole 25 having a diameter larger than the minimum inner diameter of the inward projection 23 is formed in a circular shape concentric with the inward projection 23 behind the inward projection 23. The rear end of the escape hole 25, that is, the rearmost end of the inner periphery of the tightening member 20, forms a concentric circle with the tightening member 20, and the inner diameter is slightly larger than the outer diameter of the pipe P. An insertion hole 26 having a size smaller than the inner diameter of 25 is formed in the rear end face of the fastening member 20 so as to open.

  The region in the hollow of the fastening member 20 that is in front of the inward projection 23 and behind the flat surface 10a of the joint body 10 has a constant inner diameter and is concentric with the fastening member 20. The accommodation space 22 is formed. Further, the outer periphery of the tightening member 20 is a jig fitting part 27 having a regular hexagonal shape, similar to the jig fitting part 12 of the joint body 10. A flat contact surface 28 perpendicular to the axial direction is formed on the front end surface of the jig fitting portion 27. The contact surface 28 comes into contact with the contact surface 13 of the joint body 10 in a surface contact state.

  Both the front and rear tightening rings 30 and 40 are made of copper like the pipe P, and have thin tubular tightening portions 32 and 42 protruding forward from the ring bodies 31 and 41. The outer periphery of the tightening portions 32 and 42 has a smaller diameter than the outer periphery of the ring bodies 31 and 41, and the inner periphery of the tightening portions 32 and 42 is smoothly connected to the inner periphery of the ring bodies 31 and 41.

  The outer periphery of the tightening portion 32 of the front tightening ring 30 is a tapered surface 33 (diameter reducing means that is a constituent element of the present invention) that decreases in diameter toward the front. The angle is smaller than that of the rear tapered surface 16c of the main body 10. On the inner periphery of the ring main body 31 of the front tightening ring 30, a tapered surface 34 (diameter reducing means which is a constituent element of the present invention) whose diameter decreases toward the front is formed. Further, the front surface of the ring body 31 of the front tightening ring 30 is opposed to the flat surface 10 a and the corner edge portion 10 b of the joint body 10 and from the tapered surface 33 on the outer peripheral side of the tightening portion 32 of the front tightening ring 30. Is also a tapered contact surface 35 having a large inclination angle. The tapered surface 33 on the outer peripheral side of the tightening portion 32 of the front tightening ring 30 forms an angle smaller than 45 ° with respect to the insertion direction of the pipe P with respect to the joint body 10, whereas the tapered contact surface 35. Is at an angle greater than 45 ° with respect to the insertion direction of the pipe P.

  On the other hand, the outer periphery of the tightening portion 42 of the rear tightening ring 40 is a tapered surface 43 (diameter reducing means that is a constituent element of the present invention) that decreases in diameter toward the front, and the inclination angle of the tapered surface 43 is as follows. The angle is smaller than the taper surface 34 of the ring body 31 of the front tightening ring 30.

  Further, an outward projecting portion 44 is formed as a holding means on the extending portion from the rear end surface of the rear tightening ring 40. The outer diameter of the outward protrusion 44 is slightly larger than the inner diameter of the inward protrusion 23 of the fastening member 20, and the outward protrusion 44 and the inward protrusion 23 are locked. Due to the action, the rear fastening ring 40 is held against the fastening member 20 in a state of being accommodated in the accommodation space 22.

  The flare connection part M which is the connection partner of the flare connection mechanism Cb is, for example, an operation valve fixed to a connection pipe extending from a compressor and a condenser of an outdoor unit of a cold air conditioner (air conditioner) or a cold air conditioner. It is formed in the pipe joint fixed to the connection pipe extended from the expansion valve and evaporator of an indoor unit. The flare connection portion M has a cylindrical shape as a whole, and the center hole is a circular flow hole Ma communicating with a flow path for flowing a fluid (refrigerant gas) of the outdoor unit. On the outer periphery of the front end portion of the flare connection portion M, a tapered flare sheet surface Mb that is concentric with the flow hole Ma and has a diameter reduced toward the tip (the pipe joint Ja side) is formed. In addition, a male screw portion Mc concentric with the flow hole Ma and the flare sheet surface Mb is formed in a region behind the flare sheet surface Mb on the outer periphery of the flare connection portion M.

  Next, the flare connection mechanism Cb will be described. A tapered connection surface 50 that is reduced in diameter toward the front is formed at the rear end of the joint body 10. The taper angle of the tapered connection surface 50 is larger (steep slope) than the taper angle of the flare sheet surface Mb. Further, a C-shaped ring 53 in which a rear end portion of a cylindrical lock member 51 (locking means which is a constituent element of the present invention) is fitted in an inner peripheral groove 52 is connected to the outer periphery of the joint body 10. By engaging with the large-diameter portion 54 at the front end of the main body 10 from the rear side, the main body 10 is attached so as to be free to rotate in the circumferential direction in a state in which the relative displacement forward is restricted. A female screw portion 55 that can be engaged with the male screw portion Mc of the flare connection portion M is formed on the inner periphery of the lock member 51. The outer periphery of the lock member 51 is a jig fitting portion 56 having a hexagonal shape for fitting a jig.

Next, the operation of this embodiment will be described.
First, the pipe P is connected to the rear end side pipe connection mechanism Ca from the rear. When connecting, the rear fastening ring 40 is inserted into the fastening member 20 from the front and held in an assembled state in advance. When inserted, the outward projecting portion 44 of the rear tightening ring 40 abuts the inward projecting portion 23 of the tightening member 20, but the difference in diameter between the two is negligible. If the finger is pushed in the direction, the outward projection 44 passes through the inward projection 23 while being slightly elastically reduced in diameter due to the inclination of the guide surface 24. After passing, the outward projection 44 is elastically restored. Is accommodated in the relief hole 25 of the fastening member 20. In this state, since the outward protrusion 44 is sandwiched between the inward protrusion 23 and the opening edge of the insertion hole 26, the rear tightening ring 40 is restricted from being separated from the tightening member 20. Kept in a state.

  Thereafter, the front fastening ring 30 is inserted into the fastening member 20 from the front, and the front fastening ring 30 and the assembled fastening member 20 and the rear fastening ring 40 are connected to the joint body 10. Temporarily assembled from behind, the female screw portion 21 of the fastening member 20 is screwed into the male screw portion 11 of the joint body 10. At this time, the fastening portions 32 and 42 of the fastening rings 30 and 40 are not yet deformed. Further, the contact surface 28 of the tightening member 20 is at a position spaced rearward from the contact surface 13 of the joint body 10.

  The front end portion of the pipe P is inserted into the pipe joint Ja temporarily assembled in this way from the rear. The inserted pipe P sequentially passes through the insertion hole 26 of the fastening member 20, the rear fastening ring 40, and the front fastening ring 30, and enters the constant diameter surface 16b and the front tapered surface 16a of the joint body 10. Then, when the front end of the pipe P hits a position in the middle of the inner peripheral surface of the front tapered surface 16a (a position behind the stopper 17) and stops in advance, the manual insertion of the pipe P is finished.

  Thereafter, a jig (not shown) such as a spanner is fitted to the jig fitting portion 12 of the joint body 10 and the jig fitting portion 27 of the fastening member 20, and the fastening member 20 is screwed forward. Rotate in the direction to advance. As the tightening member 20 is screwed, the outer periphery of the pipe P is tightened by being plastically deformed so that the tightening portions 32 and 42 of the front and rear tightening rings 30 and 40 are reduced in diameter.

  In other words, the tightening member 20 moves forward and presses the rear end surface of the ring body 41 of the rear tightening ring 40 forward by the inwardly protruding portion 23, and the outer peripheral front end edge of the tightening portion 42 of the tightening ring 40. Is lightly abutted against the inner peripheral tapered surface 34 of the front tightening ring 30 and stopped in front, and the outer peripheral front end edge of the tightening portion 32 of the front tightening ring 30 is lightly attached to the rear tapered surface 16c of the joint body 10. It abuts and stops in front. The contact at this time is such that the outer periphery of the front end of the tightening portion 42 on the rear side is in line contact with the tapered surface 34 of the front tightening ring 30 in the circumferential direction, and the outer peripheral edge of the front end of the tightening portion 32 on the front side is This is a form in which line contact is made in the circumferential direction with respect to the rear tapered surface 16c.

  Thereafter, as the tightening member 20 is screwed and the front and rear tightening rings 30 and 40 are advanced, the tightening portion 42 of the rear tightening ring 40 is inclined to the tapered surface 34 of the front tightening ring 30. Accordingly, the tightening portion 32 of the front tightening ring 30 is deformed in accordance with the inclination of the rear tapered surface 16c. As the diameter reduction progresses, the contact form of the tapered surface 43 on the outer periphery of the rear fastening ring 40 with respect to the tapered surface 34 of the front fastening ring 30 shifts from the line contact state to the surface contact state, and the rear part The contact form of the taper surface 34 of the front tightening ring 30 with respect to the taper surface 16c shifts from line contact to surface contact, and these surface contact regions are gradually rearward (base end side) from the outer peripheral front ends of the tightening portions 32 and 42. Expand to.

  At this time, since the rear end portion of the joint body 10 is thick in the radial direction and does not deform outward in the radial direction, the fastening portion 32 of the front fastening ring 30 sinks into the inner peripheral side of the joint body 10. The diameter is surely reduced and deformed. Similarly, since the ring body 31 of the front tightening ring 30 is also thick in the radial direction and is difficult to deform radially outward, the tightening portion 42 of the rear tightening ring 40 is also the inner periphery of the ring body 31. It is surely deformed and reduced in diameter while sinking to the side.

  Then, the tightened portions 32 and 42 having undergone the diameter reduction have their front end inner peripheral portions bite into the outer periphery of the pipe P like a wedge. Further, the tapered contact surface of the front tightening ring 30 is 35, and contacts with the corner edge portion 10b at the boundary between the flat surface 10a and the rear taper surface 16c so as to bite the corner edge portion 10b.

  In the normal tightening state, the tightening portions 32 and 42 of the two tightening rings 30 and 40 tighten the outer periphery of the pipe P at two front and rear positions, and the tightening portions 32 and 42 bite into the pipe P, whereby the outer periphery of the pipe P And the tightening portions 32 and 42 are in close airtight contact with each other while causing plastic deformation, the space between the pipe P and the tightening rings 30 and 40 is sealed, and the pipe P is locked in a retaining state. The Note that the contact portion between the rear tightening ring 40 and the pipe P is located behind the contact area between the front tightening ring 30 and the joint body 10. The close contact region between the front tightening ring 30 and the pipe P is located within the range of the close contact region between the rear tapered surface 16c and the tapered surface.

  Further, the rear tapered surface 16 c of the joint body 10 and the tapered surface 33 of the front fastening ring 30 are in surface contact, and the corner edge portion 10 b bites into the tapered contact surface 35 of the front fastening ring 30. Thus, the space between the front fastening ring 30 and the joint body 10 is sealed. Furthermore, the taper surface 34 of the front tightening ring 30 and the taper surface 43 of the rear tightening ring 40 are in surface contact, so that the space between the tightening rings 30 and 40 is also sealed. Moreover, in the contact | adherence area | region of the surface contact state of the taper surfaces 34 and 43 of the clamping rings 30 and 40, the loosening to the front-back direction and the circumferential direction is prevented by frictional resistance. Furthermore, the frictional resistance between the corner edge portion 10b and the tapered surface contact surface 35, the frictional resistance between the rear end surface of the ring body 31 and the front end surface of the ring body 41, and the inward direction with respect to the rear end surface of the ring body 41 Due to the frictional resistance with the front surface of the protrusion 23, the tightening rings 30 and 40 function as a lock nut, whereby the displacement of the tightening member 20 in the circumferential direction relative to the joint body 10, that is, the tightening member 20 Looseness is prevented.

  Now, in the process in which the tightening member 20 is screwed, a normal tightening state is reached in the middle of the tightening stroke. That is, when the tightening rings 30 and 40 reach a normal tightening state, the contact surface 28 of the tightening member 20 does not contact the contact surface 13 of the joint body 10, and both contact surfaces 13. , 28 are spaced apart in the front-rear direction. At this time, the operator cannot recognize that the tightening rings 30 and 40 are in the normal tightening state, but on the work manual, the tightening members until the contact surfaces 13 and 28 come into contact with each other. Since the screwing of 20 is to be continued, the work of screwing the tightening member 20 is continued even after the normal tightening state is reached. When the tightening member 20 is screwed until the contact surfaces 13 and 28 come into contact with each other, the tightening member 20 is stopped in front and the further screwing is restricted. Thus, the connection work of the pipe P is completed.

  While the screwing of the tightening member 20 is continued until the contact surfaces 13 and 28 come into contact with each other after the normal tightening state is reached, the tightening portion 42 of the rear tightening ring 40 is connected to the front tightening ring 30 and the pipe. Since the fastening portion 32 of the front fastening ring 30 continues to sink between the inner periphery of the joint body 10 and the outer periphery of the pipe P, the fastening rings 30 and 40 are in a normal tightening state. Keep. Further, the biting of the corner edge portion 10b with respect to the tapered contact surface 35 of the front tightening ring 30 becomes deeper. That is, the regular tightening state, the waterproof performance (seal performance) resulting from the regular tightening, and the pipe P retaining function (lock function) are maintained.

  Further, as the contact surfaces 13 and 28 approach each other, the volume of the accommodation space 22 formed between the receiving surface 10a of the joint body 10 and the inward projection 23 of the fastening member 20 is The ring main body 31 of the front tightening ring 30 and the ring main body 41 of the rear tightening ring 40 occupy almost the entire accommodation space 22 as they are reduced in the front-rear direction. That is, the volume of the air pocket in the accommodation space 22 becomes very small.

  After the pipe P is connected as described above, the pipe joint Ja is connected to the flare connection portion M. At the time of connection, the female screw portion 55 of the lock member 51 is screwed into the male screw portion Mc of the flare connection portion M, and the lock member 51 is rotated. Then, the tapered connection surface 50 comes into contact with the flare sheet surface Mb. As shown in FIG. 5, the contact form at this time is such that the tapered connection surface 50 is in contact with the inner peripheral side region of the flare sheet surface Mb. This is a line contact state in which the inner peripheral region continues in the circumferential direction.

  Thereafter, as the locking member 51 rotates and the fitting of the pipe joint Jc with respect to the flare connection portion M proceeds, the contact form between the tapered connection surface 50 and the flare sheet surface Mb changes from the line contact state to the surface contact state. The contact area gradually expands to the outer peripheral side (rear). Here, since the line contact region at the beginning of contact is the region having the smallest diameter in the flare sheet surface Mb and the tapered connection surface 50, the present embodiment is compared with the embodiment in which contact is started from the outermost diameter portion. In the case of the form, the contact area of the contact region is small in the initial process in which the contact region expands, and accordingly, the axial pressure applied to the contact region of both surfaces Mb and 50 due to tightening of the lock member 51 is large. . Therefore, the adhesive force in the contact area of both surfaces Mb and 50 is high, and the sealing performance between both surfaces Mb and 50 is improved accordingly. Then, as the rotation of the lock member 51 proceeds, as shown in FIG. 6, when the surface contact area between the flare sheet surface Mb and the tapered connection surface 50 is expanded to almost the entire area of both surfaces Mb, 50, The connection work of the pipe joint Ja to the flare connection part M is completed.

  In the state where the connection between the flare connection portion M and the pipe joint Ja is completed, the locking member 51 locks both the M and Ja to the connected state, and the flare sheet surface Mb and the tapered connection surface 50 contact the flare. The connection portion between the connection portion M and the device connection portion Cb is sealed, and the fluid flowing through the flow hole Ma and the through hole 15 does not leak to the outside.

According to the pipe joint Ja of the first embodiment, the following operations and effects are achieved.
(A) Conventionally, the end portion of the pipe P is subjected to flare processing that is deformed into a trumpet shape in accordance with the inclination of the tapered flare sheet surface Mb of the flare connection portion M, and then the pipe is formed using the lock member 51. Although the flare processing part of P was connected to the flare connection part M, when the pipe joint Ja of this embodiment is used, when connecting the pipe P, the pipe P is inserted into the joint body 10 and tightened. Since it is only tightened by the attached rings 30 and 40, it is not necessary to flare the pipe P.

  (B) The tightening rings 30 and 40 abut against the inner periphery of the joint body 10 at a plurality of locations, and the tightening rings 30 and 40 are tightened against the pipe P at a plurality of locations. Excellent in reliability.

  (C) Prior to the insertion of the pipe P, the fastening member 20 is temporarily assembled in a state where it is screwed shallowly with the joint body 10, but is locked to the fastening member 20 and the rear fastening ring 40. Since the holding means for holding the tightening ring 40 in the assembled state with respect to the tightening member 20 is provided, the rear tightening ring 40 is assembled to the tightening member 20 so that both the units 20 and 40 are unitized. Thus, the work of temporarily assembling the fastening member 20 to the joint body 10 is facilitated.

  (D) From the position where the tightening rings 30 and 40 are in the normal tightening state with respect to the pipe P, the screw member 20 is further screwed to abut the pair of contact surfaces 13 and 28. Meanwhile, since the tightening rings 30 and 40 are kept in a normal tightening state, the tightening of the tightening rings 30 and 40 to the pipe P is not loosened. Therefore, when the pipe P is connected, if an operation manual is set that the tightening member 20 is screwed up to a position where the pair of contact surfaces 13 and 28 abut against each other, it is determined whether or not the operator has completed the operation. It can be easily and reliably determined visually.

  (E) When the pipe P is connected, it is only necessary to screw the fastening member 20 into the joint body 10, so that it is not necessary to use fire unlike the case of connecting by brazing.

(F) A tapered front taper surface 16a (front stop surface) with which the outer peripheral edge of the front end portion (tip in the insertion direction) of the pipe P abuts is formed on the inner periphery of the joint body 10, and this front taper surface 16a became a stopper which stops the inserted pipe P forward. Thereby, the position of the pipe P when the screwing of the tightening member 20 is started can be determined.
Further, when the tightening proceeds, the tightening rings 30 and 40 move in the axial direction of the pipe P according to the inclination of the tapered surface of the diameter reducing means while reducing the diameter. In the case where the front surface is stopped in the form of abutting the surface, a frictional resistance is generated between the pipe P and the tightening rings 30 and 40, and the tightening torque of the tightening member 20 is increased. Is done. However, according to the present embodiment, the outer peripheral edge of the pipe P is brought into contact with the tapered front stop surface (front taper surface 16a), so that the pipe P together with the fastening rings 30 and 40 is used. Can also move forward in the insertion direction, thereby reducing the frictional resistance between the pipe P and the tightening rings 30 and 40 and improving workability.
Furthermore, when the tightening member 20 is screwed from the state where the pipe P is stopped in front, the pipe P is pushed and moved together with the tightening rings 30 and 40 in the insertion direction. Since the leading edge of the insertion direction of P and the front tapered surface 16a bite each other, the return of the pipe P and the loosening of the fastening member 20 are prevented by the frictional resistance caused by this biting.

  (G) The inclination angles of the rear taper surface 16c on the joint body 10 side and the taper surface 33 on the front tightening ring 30 side constituting the diameter reducing means are different from each other for the following reason. If both the tapered surfaces 16c and 33 have the same inclination angle, surface contact occurs when both the tapered surfaces come into contact with each other, and the frictional resistance increases rapidly. As a result, the joint body 10 is tightened. The rings 30 and 40 cannot be displaced relative to each other in the axial direction (the pipe P insertion direction), and the tightening portions 32 and 42 cannot be deformed in a reduced diameter, or the thin tightening portions 32 and 42 may be buckled. . On the other hand, in the present embodiment, since the inclination angles of the two tapered surfaces 16c and 33 are different from each other, when the two tapered surfaces 16c and 33 come into contact with each other, a line contact state in the circumferential direction is brought about, so that the surface contact occurs. Compared to the state, the tendency to increase the frictional resistance is alleviated, the tightening rings 30 and 40 can be smoothly advanced, and buckling of the tightening portions 32 and 42 is prevented. As the contact of the tapered surfaces 16c and 33 progresses, the contact area between the two 16c and 33 increases. However, since the contact area gradually increases, the increase in frictional resistance is also gentle. The tightening portions 32 and 42 can be reliably reduced in diameter while being relatively displaced with respect to the joint body 10.

  (H) When the tightening rings 30 and 40 are in the proper tightening state, the rear tapered surface 16c on the joint body 10 side and the tapered surface 33 on the front tightening ring 30 side that constitute the diameter reducing means are surfaces of each other. Since the taper surface 34 of the front tightening ring 30 and the taper surface 43 of the rear tightening ring 40 are in close contact with each other while being in close contact with each other, the frictional resistance between them and the biting action This makes it difficult for the two tapered surfaces 16c, 33, 34, and 43 to be separated from each other, and the tightening rings 30 and 40 are prevented from loosening.

  (I) Since the accommodation space 22 communicates with the outside, the moisture that has entered the accommodation space 22 from the outside is frozen by the heat of the low-temperature refrigerant passing through the pipe P and is frozen. There is a concern that the member such as the fastening member 20 may be deformed or damaged by the expansion. However, in the present embodiment, the ring bodies 31 and 41 having a diameter larger than the tightening portions 32 and 42 are formed in the tightening rings 30 and 40 housed in the housing space 22, and the ring bodies 31 and 41 are housed. Since most of the volume of the space 22 is occupied, the volume of the air pool in the accommodation space 22, that is, the space where moisture can enter from the outside is extremely small. Therefore, the expansion of the volume caused by the freezing of the moisture that has entered the housing space 22 can be suppressed, and deformation and breakage of components such as the fastening member 20 can be prevented.

  (J) Since the fastening rings 30 and 40 are accommodated in the fastening member 20 and cannot be visually confirmed from the outside, when the fastening rings 30 and 40 are made of a material different from the pipe P, There is a concern that only the tightening rings 30 and 40 are deteriorated due to use in a poor environment, and the deterioration of the tightening rings 30 and 40 is overlooked. However, in this embodiment, since the fastening rings 30 and 40 are made of the same copper as the pipe P (pipe) that can be visually confirmed, the deterioration of the fastening rings 30 and 40 is confirmed by visually confirming the deterioration state of the pipe P. Thus, it is possible to avoid the deterioration of the fastening rings 30 and 40 being overlooked.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS. The pipe joint Jb of the second embodiment is different from the first embodiment in the configuration of the pipe connection mechanism. Since other configurations are the same as those of the first embodiment, the same configurations are denoted by the same reference numerals, and descriptions of structures, operations, and effects are omitted.

  In the pipe connection mechanism Cc of the second embodiment, only one fastening ring is provided on the joint body 10. The fastening ring 60 is made of copper like the pipe P, and has a cylindrical shape surrounding the pipe P inserted into the joint body 10. The tightening ring 60 includes a thick ring body 61 and a thin tightening portion 62 extending forward from the ring body 61. On the outer peripheral surface of the tightening portion 62, a tapered surface 63 (a diameter reducing means which is a constituent element of the present invention) is formed in a form of reducing the diameter toward the front. The inclination angle of the tapered surface 63 is set to be smaller than the rear tapered surface 16c of the joint body 10.

  A substantially front half portion of the inner periphery of the tightening portion 62 is a front inclined surface 64 that is substantially parallel to the tapered surface 63 on the outer peripheral side, and a substantially rear half portion of the inner periphery is a rear portion having a smaller inclination angle than the front inclined surface 64. An inclined surface 65 is provided. At the boundary between the front and rear inclined surfaces 64 and 65, an edge-shaped biting portion 66 that is pointed obliquely forward and inward is continuously formed over the entire circumference. The inner diameters of the front inclined surface 64, the rear inclined surface 65, and the biting portion 66 are slightly larger than the outer diameter of the pipe P. A front end surface of the ring body 61 of the tightening ring 60 is a tapered contact surface 67. Also. An outward projection 68 is formed on the rear end surface of the ring body 61 as a holding means.

<Embodiment 3>
Next, a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, an annular identification ring 70 is attached to the joint body 10 of the first and second embodiments so as to follow the front end surface of the jig fitting portion 12, and the identification ring 70 is a joint body. 10, and the displacement in the front-rear direction is restricted. The front surface of the identification ring 70 is a contact surface 71 that faces the contact surface 28 of the fastening member 20 of the pipe connection mechanism Ca. In the state where the contact surfaces 28 and 71 do not contact each other in the process of connecting the pipe P, the identification ring 70 is in a rotatable state, and the tightening ring 30 for the pipe P until the contact surfaces 28 and 71 contact each other. , 40, 60 is advanced and the connection of the pipe P is completed, the identification ring 70 is sandwiched between the fastening member 20 and the jig fitting portion 12 of the joint body 10 and cannot be rotated. . Therefore, based on whether the identification ring 70 can rotate, it can be determined whether the connection work of the pipe P has been correctly completed.

<Other embodiments>
The present invention is not limited to the embodiment described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.

  (1) In the pipe connection mechanism of the first embodiment, the tapered surface of the diameter reducing means is provided on all of the joint body and the front and rear fastening rings. However, according to the present invention, the tapered surface is formed by the rear fastening ring and the front part. It may be provided on only one of the fastening rings, or may be provided on only one of the front fastening ring and the fastening member.

  (2) In the pipe connection mechanism of the second embodiment, the tapered surface of the diameter reducing means is provided on both the joint body and the fastening ring. However, according to the present invention, the tapered surface is formed between the fastening ring and the fastening member. You may provide only in any one of them.

  (3) Although both the fastening ring and the pipe are made of copper in the first and second embodiments, the present invention can also be applied to a case of using a metal other than copper.

  (4) In the first and second embodiments, the joint body and the fastening member are made of brass. However, the present invention can also be applied to a case of a metal other than brass.

  (5) In the first embodiment, each tightening ring bites into the pipe at one place. However, according to the present invention, the tightening ring may bite into the pipe at two or more places.

  (6) In the second embodiment, one clamping ring bites into the pipe at two locations. However, according to the present invention, the clamping ring may bite into the pipe one by one. You may make it bite into the pipe.

  (7) In the second embodiment, two tightening rings are provided. However, according to the present invention, three or more tightening rings may be provided.

  (8) In the first and second embodiments, the constant diameter surface of the joint main body may have a form in which the front-rear length is enlarged. In this way, since the dimension that can accommodate the pipe in the joint body is ensured long, the end portion of the pipe can be connected to the joint even if the end position of the pipe fluctuates due to variations in the length of the pipe. It can be securely connected to the pipe connection mechanism of the main body.

  (9) In Embodiments 1 to 5, the joint body may be branched in the middle, and a pipe connection mechanism or a flare connection mechanism may be provided at each branch portion.

Sectional drawing of Embodiment 1 Partial enlarged sectional view showing the process of connecting pipes Partial enlarged cross-sectional view showing the pipe connected Partial sectional view showing the state of connection to the flare connection Partial enlarged sectional view showing the connection process with the flare connection Partial enlarged sectional view showing the connection completion state with the flare connection part Sectional drawing of Embodiment 2 Partial enlarged sectional view showing the process of connecting pipes Partial enlarged cross-sectional view showing the pipe connected Sectional drawing of Embodiment 3 Cross section of conventional example

Explanation of symbols

P ... Pipe Ja ... Pipe joint Ca ... Pipe connection mechanism Cb ... Flare connection mechanism M ... Flare connection part 10 ... Joint body 13 ... Contact surface 15 ... Through-hole 16c ... Rear taper surface (diameter reduction means)
20 ... Tightening member 23 ... Inward projection (holding means)
28 ... Abutting surface 30, 40 ... Clamping ring 32, 42 ... Clamping part 33, 34, 43 ... Tapered surface (diameter reducing means)
44 ... outward projection (holding means)
50 ... Tapered connection surface 51 ... Lock member (locking means)
Jb, Jc: Pipe joint 60: Fastening ring 62: Fastening part 63 ... Tapered surface (diameter reducing means)

Claims (3)

It has a through hole that can communicate with the fluid flow path,
One end of the through hole is provided with a pipe connection mechanism for connecting a metal pipe constituting the flow path,
The other end of the through hole is provided with a flare connection mechanism connected to a tapered flare connection that constitutes the flow path,
The pipe connection mechanism is
A tubular joint body made of brass and capable of inserting the pipe;
A cylindrical fastening member screwed into the joint body;
A metal clamping ring that is made of copper and has a cylindrical shape surrounding the pipe inserted into the joint body;
A taper surface inclined with respect to the pipe insertion direction, and plastically deforming in the diameter-reducing direction while tightly adhering the fastening ring to the inner periphery of the joint body as the fastening member is screwed. And the tightening ring is configured to include a diameter reducing means adapted to bite into the displacement restricted state and / or tightly adhere to the airtight state with respect to the outer periphery of the pipe,
In the state where the tightening ring is normally tightened in the pipe connection mechanism, the tightening ring and the pipe abut at a plurality of locations in the pipe insertion direction, and the tightening ring and the joint body are inserted into the pipe. Abutment is made at two locations in the direction, one of the two locations is contacted in a surface contact form, and at the other contact location, the corner edge of the joint body bites into the clamping ring. It is assumed to be in contact with the
The flare connection mechanism is:
A tapered connecting surface capable of surface contact with the flare connecting portion;
A pipe joint comprising: a locking means capable of holding the tapered connection surface in a pressed state against the flare connection portion. The holding member capable of holding the tightening ring and the tightening ring in an assembled state in which the tightening ring is separated from the tightening member by being locked to each other is provided. Item 1. A pipe joint according to Item 1. The joint main body and the tightening member are provided with a pair of contact surfaces that approach as the tightening member is screwed in a direction to reduce the diameter of the tightening ring.
In the process in which the tightening member is screwed, the tightening ring is in a normal tightening state with respect to the pipe while the pair of contact surfaces are not in contact with each other, and the screwing of the tightening member is 3. The pipe joint according to claim 1, wherein a normal tightening state of the tightening ring is maintained while the pair of contact surfaces are in contact with each other .

Images