JP6247887B2 - Pipe fitting - Google Patents

Description

  The present invention relates to a pipe joint used for connection of a connection pipe such as a metal heat medium pipe of a cold air conditioner.

  Conventionally, as this type of pipe joint, a technique described in Patent Document 1 below has been proposed. The pipe joint described in Patent Literature 1 includes an annular joint body having a receiving part into which a connection pipe such as a metal heat medium pipe of a cooling / cooling air conditioner is inserted, and a male screw formed on the outer peripheral surface of the receiving part. A tightening nut to be screwed in and an annular ferrule portion (also referred to as a “break-in sleeve”) integrally formed extending in the axial direction on the distal end side of the receiving portion of the joint main body are provided.

  In the tightening nut, a pressing portion for reducing the diameter of the ferrule portion by screwing the tightening nut is formed on the inner peripheral surface that is externally fitted to the connection pipe. In this case, the pressing portion is an annular recess that allows the distal end side of the ferrule portion to enter. The thickness of the concave portion in the radial direction is thinner than the thickness of the ferrule portion in the radial direction. Moreover, the inner diameter of the ferrule part is formed substantially equal to the outer diameter of the connection pipe.

  In the pipe joint having the above configuration, when the connecting pipe is inserted so as to extend over the ferrule part and the receiving part, and the tightening nut is screwed into the receiving part, the distal end side of the ferrule part is press-fitted into the recess, and the outer peripheral surface of the ferrule part Is pressed by the peripheral surface of the recess to reduce the diameter of the ferrule part, the outer peripheral surface of the connection pipe is pressed by the inner peripheral surface of the ferrule part to reduce the diameter of the connection pipe, and the ferrule part bites into the outer peripheral part of the connection pipe The fitting part to the receiving port of the connection pipe is sealed.

JP 2003-74769 A

  In the above-described conventional pipe joint, the outer peripheral surface of the ferrule part is pressed by the peripheral surface of the concave part, and the outer peripheral surface of the connection pipe is pressed by the inner peripheral surface of the ferrule part, so that the ferrule part bites into the outer peripheral part of the connection pipe. Then, the fitting part to the receiving part of the connection pipe is sealed. Thus, in order for the ferrule part to bite into the outer peripheral part of the connecting pipe by contact between the surfaces overlapping in the radial direction, the corresponding tightening torque applied to the tightening nut must be increased.

  In view of the above problems, an object of the present invention is to provide a pipe joint that can reduce the tightening torque applied to the tightening nut as compared with the conventional case.

  The pipe joint of the present invention includes an annular joint body having a receiving portion into which a metal connection pipe is inserted, a tightening nut screwed into a male screw formed on the outer peripheral surface of the receiving portion, and a receiving portion. And an annular ferrule portion integrally formed in the receiving portion extending along the axial direction, and the tightening nut and the ferrule portion, and screwing the tightening nut in the axial direction. And an annular clamping sleeve that moves together with it, and an annular sealing claw portion whose tip is pressed against the outer peripheral surface of the connection pipe on the inner peripheral surface of the ferrule section, and the connection pipe is inserted into the ferrule section. The inner peripheral surface of the ferrule part so that a gap having a radial width substantially corresponding to the radial height of the sealing claw part is formed between the outer peripheral surface of the connection pipe and the inner peripheral surface of the ferrule part. Is set to be larger than the diameter of the outer peripheral surface of the connecting pipe. The outer peripheral surface of the lug portion is formed substantially parallel to the shaft center, or is inclined so that the receiving portion side has a large diameter, and the inner peripheral surface of the fastening sleeve has a large diameter on the receiving portion side. The tilt angle of the inner peripheral surface of the tightening sleeve is set larger than the angle of the outer peripheral surface of the ferrule portion with respect to the axis of the ferrule portion. It is characterized by being.

  In the above configuration, the inner peripheral surface of the tightening sleeve is a surface that is inclined so as to have a larger diameter on the receiving portion side and is in contact with the distal end side of the outer peripheral surface of the ferrule portion. The inclination angle of the inner peripheral surface of the tightening sleeve is set to be larger than the angle with respect to the inner peripheral surface of the tightening sleeve, so that the front end side of the outer peripheral surface of the ferrule portion extends linearly with respect to the inner peripheral surface of the tightening sleeve. In addition, a clearance having a radial width substantially corresponding to the radial height of the claw portion for sealing is provided between the inner peripheral surface of the ferrule portion and the outer peripheral surface of the connection pipe. Since the ferrule part is not in contact with the connecting pipe, when the fastening sleeve is moved by screwing it into the receiving part so that the fastening nut is moved in the axial direction, the ferrule part can be easily moved radially inward. The seal claw is connected and arranged Since the fitting part to the receiving part of the connection pipe is sealed by biting into the outer peripheral surface of the connecting pipe and the ferrule part is formed integrally with the receiving part, the fastening sleeve is moved in the axial direction. However, the ferrule part does not move in the axial direction, and therefore the sealing claw part hardly moves in the axial direction when the sealing claw part bites into the outer peripheral surface of the connection pipe.

  In the pipe joint of the present invention, it is possible to adopt a configuration in which two sealing claws are provided apart from each other in the axial direction, and the radial heights of the two sealing claws are formed substantially the same. . By providing two sealing claws spaced apart in the axial direction as in this configuration, the fitting portion of the connection pipe to the receiving port is sealed at two locations, and the sealing performance is improved.

  In the pipe joint of the present invention, a configuration in which the angle of the tip of the claw for sealing is set to 60 ° to 120 ° can be employed. According to this structure, when the nail | claw part for a seal | sticker bites into connection piping, the tip of the nail | claw part for a seal | sticker is hard to be crushed and a sealing performance is ensured.

  In the pipe joint of the present invention, it is possible to adopt a configuration in which the inclination angle of the outer peripheral surface of the ferrule part is set to 5 ° or less, and the inclination angle of the inner peripheral surface of the fastening sleeve is set in the range of 8 ° to 20 °.

  When the inclination angle of the outer peripheral surface of the ferrule part exceeds 5 °, the outer peripheral surface of the ferrule part becomes a large inclination, and the length along the axis of the ferrule part may be shortened. In that case, it may occur that the tightening nut has to be formed longer by that amount, so that the cost may increase.

  If the inclination angle of the inner peripheral surface of the fastening sleeve is smaller than 8 °, if the length along the axis of the ferrule part is the same, in order to obtain a predetermined amount of biting in the sealing claw part, Therefore, it is necessary to increase the length of the tightening sleeve along the axis, and the manufacturing cost increases. On the other hand, if the inclination angle exceeds 20 °, the difference from the inclination angle of the outer peripheral surface of the ferrule part becomes too large, and a correspondingly large tightening torque is required, and the joint work becomes inefficient. It is done.

  In the pipe joint of the present invention, the inner peripheral surface of the fastening sleeve is a surface that is inclined so as to have a larger diameter on the receiving port side and is in contact with the distal end side of the outer peripheral surface of the ferrule portion, and the outer peripheral surface of the ferrule portion The inclination angle of the inner peripheral surface of the tightening sleeve is set to be larger than the angle with respect to the axial center of the fastening sleeve. In addition, a clearance having a radial width substantially corresponding to the radial height of the sealing claw portion is provided between the inner peripheral surface of the ferrule portion and the outer peripheral surface of the connection pipe. Since the ferrule part is not in contact with the connecting pipe, when the fastening sleeve is moved by screwing it into the receiving part so that the fastening nut is moved in the axial direction, the ferrule part is radially inward. So that the sealing nail The fitting part to the receiving part of the connection pipe is sealed by biting into the outer peripheral surface of the connecting pipe, and the ferrule part is formed integrally with the receiving part, so the clamping sleeve is moved in the axial direction. The ferrule part does not move in the axial direction even if it is used, and therefore the sealing claw part hardly moves in the axial direction when the sealing claw part bites into the outer peripheral surface of the connection pipe. The tightening torque applied to the tightening nut can be reduced as compared with the conventional case.

It is a half sectional view of a pipe joint concerning one embodiment of the present invention before tightening. It is a half sectional view after the tightening. It is an expanded sectional view of the same ferrule part and a fastening sleeve. It is a single figure of the joint main part, (a) is a figure from the direction of an axial center, and (b) is a half sectional view. It is a single figure of the same fastening sleeve, (a) is a figure from the direction of an axial center, and (b) is a half sectional view.

  Hereinafter, a pipe joint according to an embodiment of the present invention will be described with reference to the drawings. The pipe joint of this embodiment is used to connect connection pipes such as metal heat medium pipes of a cold air conditioner, and is also referred to as a fireless joint. As shown in FIGS. 1 and 2, the pipe joint 1 includes a joint body (also referred to as “inner”) 2, a ferrule part 3, a fastening nut 4, and a fastening sleeve 5.

  As shown in FIGS. 4 (a) and 4 (b), the entire joint body 2 is formed in an annular shape, and a polygonal tool hanging portion 7 on which a tool such as a spanner is hung is projected at the central portion in the axial center 6 direction. Is formed. On both outer sides of the joint body 2 with respect to the central portion in the direction of the axis 6, a receiving portion 9 into which the distal end side of the connecting pipe 8 made of metal to be connected is inserted is formed. The outer diameter of each receiving portion 9 is smaller than that of the tool hook portion 7. A male screw 9 b is formed on the outer peripheral surface of each receiving port 9.

  Each ferrule part 3 is formed in an annular shape, and extends to the tip side of the receiving part 9 along the axis 6 so as to be formed integrally with the receiving part 9. The outer diameter of the ferrule part 3 is set smaller than the outer diameter of the receiving part 9. Specifically, the outer peripheral surface of the receiving port portion 9 and the outer peripheral surface 3a of the ferrule portion 3 are continuously formed via an annular stepped surface 3b along the radial direction.

  The outer peripheral surface 3a of the ferrule portion 3 is an inclined surface that is inclined so as to have a large diameter on the receiving portion 9 side. The inner peripheral surface 3 c of the ferrule portion 3 is set to have a larger diameter than the inner peripheral surface of the receiving portion 9. The inner peripheral surface 3 c of the ferrule part 3 is a cylindrical surface parallel to the axis 6. As shown in FIG. 4, the inner diameter of the receptacle 9 and the inner diameter of the ferrule 3 have an inner diameter difference of a radial dimension δh. A tip surface (end surface away from the central portion of the joint body 2 in the direction of the axial center 6) 3d of the ferrule portion 3 is a surface along the radial direction orthogonal to the axial center 6.

  The inclination angle θX of the outer peripheral surface 3a of the ferrule part 3 with respect to the horizontal plane along the axis 6 is set to 0 <θX ≦ 5 °. The outer peripheral surface 3a of the ferrule part 3 is inclined over substantially the entire longitudinal direction (direction along the axis 6).

  As shown in FIGS. 3 and 4, the ferrule portion 3 is press-contacted to the outer peripheral surface 8 a of the connection pipe 8 on the inner peripheral surface 3 c on the end portion side away from both sides of the axial center 6 direction of the joint body 2. An annular sealing claw portion 11 having a pointed portion 10 is integrally provided. The two sealing claws 11 are arranged so as to be continuous, one sealing claw 11 is formed at the tip of the inner peripheral surface 3c of the ferrule part 3, and the other sealing claw 11 is one sealing It is formed inward of the axial center 6 direction with respect to the claw portion 11. That is, the claw portions 11 for sealing are disposed in pairs on the respective ferrule portions 3 so as to be separated from each other in the direction of the axis 6.

  As shown in FIG. 4, the radial heights of the two sealing claws 11 are formed substantially the same. Specifically, the distance from the inner peripheral surface 3c of the ferrule part 3 which is the base end of both the sealing claw parts 11 to the inner diameter end side of the pointed part 10 is set substantially equal to the radial dimension δh. Both of the cross-sectional shapes of the sealing claw portions 11 are formed in a substantially triangular shape, and the angle θ1 formed by the pointed portion 10 is set to 60 ° to 120 °. The pointed portion 10 is a radially inner end portion of the sealing claw portion 11. The inner diameter end side of the tip portion 10 has an annular linear shape. In other words, the pointed portion 10 can contact the outer peripheral surface 8a of the connection pipe 8 in line contact over the circumferential direction.

  In the substantially triangular shape which is the cross-sectional shape of the sealing claw portion 11, two sides which are inclined toward the inner diameter end side (annular side indicated by reference numeral 11c in FIG. 4A) which is the pointed portion 10 are in the direction of the axis 6 Are inclined in opposite directions with respect to the radial direction intersecting the two, and the inclination angles θ2 and θ3 of the two sides are different. In the present embodiment, the inclination angle θ2 of the one side 11a outside the axial center 6 direction is set to be larger than the inclination angle θ3 of the one side 11b inside the axial center 6 direction.

  Thus, the diameter of the inner peripheral surface 3c of the ferrule part 3 is such that the outer peripheral surface 8a of the connection pipe 8 and the inner peripheral surface 3c of the ferrule part 3 in a state where the tip side of the connection pipe 8 is inserted into the ferrule part 3. Is set larger than the diameter of the outer peripheral surface 3a of the connection pipe 8 so that a gap 12 having a radial width substantially corresponding to the radial height of the claw portion 11 for sealing is generated. In other words, the gap 12 is not provided by the claw portion 11 for sealing, but the inner peripheral surface of the ferrule portion 3 so that the gap 12 is formed in advance in a state where the distal end side of the connection pipe 8 is inserted into the ferrule portion 3. A diameter of 3c is set.

  The tightening nut 4 is formed in an annular shape, and is screwed into a male screw 9 b formed on the outer peripheral surface 9 a of the receiving port 9. On the inner peripheral surface of the tightening nut 4, a female screw 13 that is screwed into a male screw 9 b formed on the outer peripheral surface of the receiving port 9 is formed. An annular housing recess 14 for housing the fastening sleeve 5 is formed on the outer side of the female screw 13 in the axial center 6 direction. Furthermore, a pipe insertion portion 15 into which the connection pipe 8 can be inserted is formed outside the tightening nut 4 in the direction of the axis 6. The front end surface 4 a of the tightening nut 4 can come into contact with the one end surface 7 a of the tool hook 7.

  As shown in FIG. 5A, the tightening sleeve 5 is formed in an annular shape and is disposed so as to be sandwiched between the tightening nut 4 and the ferrule portion 3, and the tightening nut 4 is screwed in the direction of the axis 6 thereof. Configured to move with. The cross-sectional shape of the fastening sleeve 5 along the axis 6 is a trapezoid. The inner peripheral surface 5a of the tightening sleeve 5 presses the outer peripheral surface 3a of the ferrule part 3 toward the inner diameter side while moving with the screwing of the tightening nut 4, and the receiving part 9 side has a larger diameter. Inclined.

  As shown in FIGS. 3 and 5B, the inclination angle θY of the inner peripheral surface 5a of the tightening sleeve 5 with respect to the horizontal plane including the axis 6 is set to 8 ° ≦ θY ≦ 20 °. The inner peripheral surface 5a of the fastening sleeve 5 is inclined over substantially the entire longitudinal direction (direction along the axis 6). Thus, the inclination angle θY (8 ° ≦ θY ≦ 20 °) of the inner peripheral surface 5a of the fastening sleeve 5 is larger than the inclination angle θX (0 <θX ≦ 5 °) of the outer peripheral surface 3a of the ferrule portion 3. It is set large.

  The distal end surface (end surface away from the central portion of the joint body 2 in the direction of the axial center 6) 5b and the proximal end surface 5c are surfaces along the radial direction orthogonal to the axial center 6. The front end surface 5b is a surface that comes into contact with the end surface of the housing recess 14 of the tightening nut 4 and is pressed in the direction of the axis 6 by the end surface. The base end surface 5c of the fastening sleeve 5 is a surface that can contact the stepped surface 3b.

  In the pipe joint 1 having the above-described configuration, as shown in FIG. 1, the distal end side of the connection pipe 8 is inserted so as to extend over the ferrule part 3 and the receiving port part 9, and then the tightening nut 4 is connected to the shaft center 6. Screw into the receptacle 9 to move in the direction. Then, the base end surface 5c of the tightening sleeve 5 accommodated in the accommodating recess 14 is pressed in a state of being accommodated in the pipe insertion portion 15 of the tightening nut 4, and the tightening sleeve 5 moves in the direction of the axis 6.

  The inner peripheral surface 5 a of the fastening sleeve 5 is inclined with respect to the outer peripheral surface 3 a of the ferrule part 3. For this reason, when the tightening sleeve 5 moves in the direction of the axis 6, the tip end side corner 3 e of the outer peripheral surface 3 a of the ferrule portion 3 comes into line contact with the inner peripheral surface 5 a of the tightening sleeve 5. In the state (line contact state in the circumferential direction), the inner peripheral surface 5a of the fastening sleeve 5 presses the outer peripheral surface 3a of the ferrule part 3 so that the radial width of the gap 12 is reduced. Thereby, the ferrule part 3 is reduced in diameter. However, the gap 12 is not completely crushed but remains as shown in FIG.

  Thus, by inclining the inner peripheral surface 5a of the tightening sleeve 5 with respect to the outer peripheral surface 3a of the ferrule portion 3, the tightening torque to be applied to the tightening nut 4 can be reduced accordingly. Since the fastening sleeve 5 is separated from the fastening nut 4, the joint body 2 can be prevented from rotating together when the fastening nut 4 is rotated.

  The ferrule part 3 is integrally provided with an annular sealing claw part 11 provided with a pointed end part 10 that is pressed against the outer peripheral surface 8a of the connection pipe 8 on the inner peripheral surface 3c on the end side. When the diameter of the ferrule portion 3 is reduced as described above, the ferrule portion is configured such that the inner diameter end side of the tip portion 10 of the sealing claw portion 11 is pressed against the outer peripheral surface 8a of the connection pipe 8 and the gap 12 is filled. 3 is bent and the tip 10 of the claw portion 11 for sealing bites into the outer peripheral surface 8a of the connection pipe 8, and the fitting portion of the connection pipe 8 to the receiving portion 9 is sealed. Note that the tightening nut 4 is moved along the axis 6 until the tip end surface 4 a is brought into contact with the one end surface 7 a of the tool hook 7.

  Between the inner peripheral surface 3 c of the ferrule portion 3 and the outer peripheral surface 8 a of the connection pipe 8, a gap 12 having a radial width substantially corresponding to the radial height of the sealing claw portion 11 is provided. For this reason, the thickness of the ferrule part 3 in the radial direction can be reduced, and the diameter of the ferrule part 3 can be reduced more easily.

  Furthermore, the ferrule part 3 is formed integrally with the receiving part 9 (joint body 2). For this reason, even if the fastening sleeve 5 moves in the direction of the axis 6, the ferrule part 3 does not move in the direction of the axis 6. Therefore, the sealing claw portion 11 also does not move in the direction of the axis 6. In other words, it is not necessary to move the sealing claw portion 11 in the direction of the axis 6 in a state where the sealing claw portion 11 has bitten into the outer peripheral surface 8a from the radially outer side of the connection pipe 8. As a result, the claw portion 11 for sealing does not receive resistance in the direction of the axis 6 from the outer peripheral surface 8a of the connection pipe 8, and the tightening torque applied to the tightening nut 4 can be reduced accordingly.

  In this embodiment, both the cross-sectional shapes of the sealing claw portion 11 are formed in a substantially triangular shape, and the sealing claw portion 11 is radially outward of the connecting pipe 8 by setting the angle θ1 = 60 ° to 120 °. From the above, it became clear that even if it bites into the outer peripheral surface 8a, it is not easily crushed. Therefore, by setting the angle θ1 = 60 ° to 120 °, the fitting portion of the connection pipe 8 to the receiving portion 9 can be reliably sealed. Moreover, in this embodiment, since the sealing claw portions 11 are formed in pairs, a more reliable sealing can be realized accordingly.

  In the present embodiment, the inclination angle θX of the outer peripheral surface 3a of the ferrule portion 3 with respect to the horizontal plane along the axis 6 is set to 0 <θX ≦ 5 °. When θX exceeds 5 °, the outer peripheral surface 3a of the ferrule part 3 becomes a large inclination, and the length along the axis 6 of the ferrule part 3 may be shortened. In this case, it may occur that the tightening nut 4 has to be formed longer by that amount, so that the cost may increase.

  In the present embodiment, the inclination angle θY of the inner peripheral surface 5a of the fastening sleeve 5 with respect to the horizontal plane including the axis 6 is set to 8 ° ≦ θY ≦ 20 °. If the inclination angle of the inner peripheral surface of the tightening sleeve is smaller than 8 ° and the length of the ferrule portion 3 along the axis 6 is the same, in order to obtain a predetermined amount of biting in the sealing claw portion 11 Therefore, it is necessary to lengthen the length of the fastening sleeve 5 along the axis 6 by that amount, which increases the manufacturing cost. On the other hand, if the inclination angle θY exceeds 20 °, the difference from the inclination angle θX of the outer peripheral surface 3a of the ferrule part 3 becomes too large, and a large tightening torque is required, and the joint work is efficient. It is thought that it will disappear.

  The present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention. The same applies to the specific configuration of each part. For example, in the above embodiment, the inclination angle θX with respect to the horizontal plane along the axis 6 of the outer peripheral surface 3a of the ferrule portion 3 is 0 <θX ≦ 5 °. However, the inclination angle θX = 0 ° (horizontal plane along the axis 6) may be used. That is, 0 ° ≦ θX ≦ 5 ° may be satisfied. Even in this case, the same effects as those of the above embodiment can be obtained.

  In the above embodiment, the sealing claw portions 11 are formed in pairs. However, the present invention is not limited to this, and the number of the sealing claw portions 11 may be one or three under the condition that the tightening torque is not excessive. . Further, although the fastening sleeve 5 is separated from the fastening nut 4, if the joint body 2 does not rotate together, the fastening sleeve 5 may be formed integrally with the fastening nut 4. Conceivable.

  DESCRIPTION OF SYMBOLS 1 ... Pipe joint, 2 ... Joint main body, 3 ... Ferrule part, 3a ... Outer peripheral surface, 3c ... Inner peripheral surface, 3e ... End surface side corner | angular part, 4 ... Tightening nut, 4a ... End surface, 5 ... Tightening sleeve 5a ... inner peripheral surface, 5b ... tip surface, 6 ... axial center, 8 ... connecting pipe, 8a ... outer peripheral surface, 9 ... receiving portion, 9a ... outer peripheral surface, 10 ... pointed end portion, 11 ... sealing claw portion, 12 ... clearance, δh ... radial dimension, θ1 ... angle of the tip, θ2 ... inclination angle, θ3 ... inclination angle, θX ... inclination angle, θY ... inclination angle

Claims (5)

An annular joint body having a receiving portion into which a metal connection pipe is inserted, a tightening nut screwed into a male screw formed on the outer peripheral surface of the receiving portion, and the receiving portion along the axial direction. An annular ferrule portion that is integrally formed in the receiving portion, and an annular tightening that is disposed between the tightening nut and the ferrule portion and moves together with screwing of the tightening nut in the axial direction. With a sleeve,
Provided on the inner peripheral surface on the tip side of the ferrule portion is an annular sealing claw portion whose tip is pressed against the outer peripheral surface of the connection pipe,
With the connecting pipe inserted into the ferrule, a gap having a radial width substantially corresponding to the radial height of the sealing claw is generated between the outer peripheral surface of the connecting pipe and the inner peripheral surface of the ferrule. The diameter of the inner peripheral surface of the ferrule part is set larger than the diameter of the outer peripheral surface of the connection pipe,
The outer peripheral surface of the ferrule part is formed so as to be substantially parallel to the axial center, or is inclined so that the receiving part side has a large diameter,
The inner peripheral surface of the tightening sleeve is inclined so that the diameter of the receiving portion side is larger, and is a surface that contacts the distal end side of the outer peripheral surface of the ferrule portion. In addition, the pipe joint is characterized in that the inclination angle of the inner peripheral surface of the fastening sleeve is set larger.   The pipe joint according to claim 1, wherein two sealing claws are provided apart from each other in the axial direction, and the radial heights of the two sealing claws are formed substantially the same.   The pipe joint according to any one of claims 1 and 2, wherein an angle of a tip of the claw portion for sealing is set to 60 ° to 120 °.   The inclination angle of the outer peripheral surface of the ferrule part is set to 5 ° or less, and the inclination angle of the inner peripheral surface of the fastening sleeve is set to a range of 8 ° to 20 °. The pipe joint according to item. The tightening sleeve is separated from the tightening nut and is accommodated in an accommodation recess formed on the inner peripheral surface of the tightening nut so as to suppress the joint body from rotating together with the rotation of the tightening nut. The pipe joint according to any one of claims 1 to 4.

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