JP5013904B2 - Pipe end joint and pipe end connection structure - Google Patents

Description

  The present invention relates to a pipe terminal joint and a pipe terminal connection structure that are used, for example, in a refrigerant pipe of an automobile air conditioner.

  A pipe end joint is used to connect a refrigerant feed pipe to a compressor or a condenser in a refrigerant pipe of an automobile air conditioner. The pipe end fitting is inserted into the pipe hole of the flange, the pipe for feeding the refrigerant, after the necessary end processing on the tip end side of the pipe, the tip end of the pipe is connected to the connection port of the compressor or the condenser, and The flange is fixed to a compressor or the like, and the refrigerant feeding pipe is connected to the compressor or the like so as not to come off.

  Such pipe end joints often require a function of preventing rotation with respect to the pipe. For example, Patent Document 1 discloses a technique for forming a convex portion in a pipe hole in order to meet such a demand. Are listed. If the pipe hole is provided with a convex part, when the diameter of the pipe end is expanded within the pipe hole, the convex part bites into the outer periphery of the pipe tip, and the pipe rotates around the pipe end joint. It will be connected in a stopped state.

  By the way, the pipe end joint described in Patent Document 1 is configured so that a bulge portion is formed at the tip of the pipe and is fixed to the compressor and the condenser so as to cover the bulge portion. Although it has a retaining function for the pipe, it does not have at least a sufficient function to prevent the pipe from being pushed. However, in order to protect the connected parts of the compressor and condenser to which the pipe is connected, or to improve the workability when connecting the pipe, the pipe end joint is also engaged with the pipe in the pushing direction. Preferably it is. In order to engage the pipe end joint with the pipe in the pushing direction, a bulge portion that engages with the periphery of the opening (back opening) of the pipe hole located on the side opposite to the tip opening of the pipe may be formed on the pipe. This requires a cumbersome punching process.

  Alternatively, for example, as described in Patent Document 2, a pipe end is formed by expanding a pipe and forming a bulging portion that swells radially outward from the back opening on the back side (back opening side) of the pipe. The joint can be provided with a function of preventing the pushing of the pipe. Here, a diameter-expanded portion for guiding the bulging portion radially outward is formed in the back opening of the pipe hole.

Japanese Patent No. 3270001 Japanese Patent No. 3488331

  By the way, in order to have a pipe detent function, a convex portion is formed in the pipe hole of the pipe end joint, and in order to have a function to prevent the pipe from being pushed in, it is radially outward from the rear opening of the pipe hole. If it is going to form the swelling part which swells in a pipe, the number of processes will increase or workability will fall, and production efficiency will not be good.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pipe end joint and a pipe end connection structure that have a function of preventing rotation and pushing-in with respect to a pipe and that can be easily fixed to a pipe hole.

  In order to achieve this object, the pipe end joint of the present invention includes a flange having a mounting portion and a pipe hole, and is fixed by inserting the end side of the fluid transfer pipe into the pipe hole and expanding the diameter. And a pipe terminal joint for fixing the attachment portion to the connected side to which the fluid transfer pipe is connected, wherein a plurality of rotation-preventing convex portions are formed in the pipe hole at intervals in the circumferential direction. An engaging groove is formed between the adjacent convex portions, and the convex portion is formed in an intermediate portion in the axial direction of the pipe hole, and an engaging concave portion is formed on both axial sides of the convex portions. Is provided. When the diameter of the fluid transfer pipe is increased by inserting the fluid transfer pipe into the pipe hole, the pipe is compressed, deformed and inserted into the engagement groove and the engagement recess, and a detent and a structure for preventing axial displacement are configured. If the protruding height of the convex portion is lowered, the deformed portion of the pipe is filled in the engaging groove and the engaging concave portion without increasing the compression ratio of the pipe. The bottom surface of the engagement groove and the bottom surface of the engagement recess can be positioned on the same cylindrical surface.

  In addition, the pipe end connection structure of the present invention includes a pipe end joint provided with a flange provided with an attachment portion and formed with a pipe hole, and a fluid transfer pipe that is fixed by inserting an end side into the pipe hole. And a pipe terminal connection structure for fixing the attachment portion to the connected side to which the fluid transfer pipe is connected, wherein the pipe hole has a convex portion for preventing rotation in the circumferential direction. Are formed, and an engaging groove is formed between the adjacent convex portions. The convex portion is formed at an axially intermediate portion of the pipe hole, and is engaged on both axial sides of the convex portions. A recess is provided, and the end side of the fluid transfer pipe is pressed from the inside, so that the outer periphery is deformed so as to follow the uneven shape of the pipe hole, and enters the engagement groove and the engagement recess. And the fluid transfer The outer diameter of the end portion side of the pipe, the back opening around the pipe bore, in which is formed the same as the diameter of the rear opening of the pipe hole. The outer diameter of the end of the fluid transfer pipe is formed around the rear opening of the pipe hole so as to be the same as the diameter of the rear opening of the pipe hole. Sufficient anti-rotation and push-in prevention or axial displacement prevention is achieved by intrusion due to deformation into the fitting groove and the engagement recess. The rear opening of the pipe hole is an opening of the pipe hole located on the opposite side to the opening end of the fluid transfer pipe.

  By using the pipe end joint or the pipe end connection structure of the present invention, it is possible to easily prevent rotation of the fluid transfer pipe and prevention of axial displacement without damaging the fluid transfer pipe.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 is a perspective view of a pipe terminal joint according to the present invention, FIG. 2 is a front view of the pipe terminal joint, and FIG. 3 is a sectional view of the pipe terminal joint.

  The pipe end joint 1 is made of aluminum, and a gourd having a constant thickness as a whole, integrally connecting a flange 3 that is a large-diameter annular body and a mounting portion 5 that is a small-diameter annular body on the outer peripheral side. The mounting portion 3 is provided with a bolt hole 7 for a mounting bolt (not shown), and the flange 3 is provided with a pipe hole 9 for a fluid transfer pipe. It has been.

  The pipe hole 9 or the inner peripheral surface 11 of the pipe hole 9 is formed with a convex portion 13 that slightly protrudes inward over the entire circumference at the center in the thickness direction (axial direction). The convex portion 13 includes a plurality of convex portions 17 having the same shape so as to form gaps (engagement grooves) 15 at equal intervals in the circumferential direction, that is, a plurality of equal intervals, that is, 8 here. Are provided. Each convex portion 17 swells in a substantially square shape and is formed so that the inner surface 19 is positioned on the same virtual cylindrical surface, but the base portion (base portion) 21 forms a square shape slightly larger than the inner surface 19. Is configured to do.

  The convex portions 17 are not formed on both sides in the axial direction. Therefore, when the convex portion 17 is used as a reference, the engagement concave portions 23 are formed on both sides of the convex portion 17 in the axial direction. In the pipe hole 9, except the convex part 17, it is located on the same cylindrical surface (inner peripheral surface 11).

  4 to 7 are diagrams for explaining a process of connecting and fixing the fluid transfer pipe to the pipe hole 9 of the pipe end joint 1, and FIG. 4 shows that the fluid transfer pipe is passed through the pipe hole 9 of the pipe end joint 1. FIG. 5 is a view showing a state in which a punch is press-fitted into the fluid transfer pipe, FIG. 6 is another view showing a state in which the punch is press-fitted into the fluid transfer pipe, and FIG. FIG. 8 is a diagram showing a state where a seal groove is formed at the tip of the fluid transfer pipe, and FIG. 9 is a comparison diagram with the case where a back side retaining bulge is formed.

  First, an aluminum-made fluid transfer pipe 25 having an outer diameter equal to, approximately equal to or slightly smaller than the inner diameter of the convex portion 13 formed in the pipe hole 9 of the pipe end joint 1 is prepared, and the tip portion 27 has a pipe hole. The fluid transfer pipe 25 is passed through the pipe hole 9 so as to pass through the pipe 9 and protrude from the pipe hole 9 (FIG. 4). Next, a punch 35 having a small-diameter tip guide portion 29, a large-diameter compression portion 31, and a large-diameter enlarged portion 33 is press-fitted into the fluid transfer pipe 25 from the tip opening 37 (FIG. 5). The outer diameter of the compression portion 31 of the punch 35 is set to be slightly larger than the inner diameter of the fluid transfer pipe 25 and slightly smaller than the inner diameter of the convex portion 13. The punch 35 is performed until the compression part 31 penetrates the pipe hole 9 and the diameter-expanded part 33 approaches the pipe hole 9. The portion of the fluid transfer pipe 25 located in the pipe hole 9 is thinly compressed by the compression portion 31 at the portion of the convex portion 13 and contacts the inner peripheral surface 11 of the pipe hole 9 at a portion other than the convex portion 13 or The diameter is expanded until approaching. Therefore, the outer periphery of the fluid transfer pipe 25 enters the entire annular portion located on both axial sides of the gap 15 and the convex portion 13. The fluid transfer pipe 25 is prevented from slipping out of the pipe hole 9 by the portion 39 enlarged in diameter by the engaging recess 23, and the diameter of the fluid transfer pipe 25 is enlarged by the gap 15 and enters the gap 15 with respect to the pipe hole 9. The rotation is prevented (see FIG. 6).

  The tip portion 27 of the fluid transfer pipe 25 protruding from the pipe hole 9 is expanded to a larger diameter than the portion located in the pipe hole 9 by the enlarged diameter portion 33 of the punch 35. On the side of the pipe hole 9, a tapered portion 43 that is continuous with a portion located in the pipe hole 9 is provided.

  Next, after punching the taper portion 43 to a slightly steep angle (FIG. 7), the seal groove 45 for disposing an annular seal member (not shown) at the tip portion 27 of the fluid transfer pipe 25 is rolled. It is formed by manufacturing (FIG. 8). Here, the opposite side of the tip 27 of the fluid transfer pipe 25 across the pipe hole 9 is formed in the same diameter as the back opening 47 of the pipe hole 9 and does not have a retaining bulge. Therefore, as shown in FIG. 9, when the bent portion 49 is formed in the fluid transfer pipe 25, the pipe height can be made lower than the pipe height H1 of the retaining bulge portion 51 formed. Yes (see height H2).

  And if the fluid transfer pipe 25 is fixed to the pipe hole 9 of the pipe terminal joint 1, the front-end | tip part 27 of the fluid transfer pipe 25 will be connected to the connection port (not shown) of the compressor which is a to-be-connected side, for example. The bolts 7 are fixed to the compressor through mounting bolts.

  If the pipe end joint or pipe end connection structure of the present invention is used, a stable pipe free from fluid leakage can be constructed.

It is a perspective view of a pipe terminal joint concerning the present invention. It is a front view of a pipe terminal joint. It is sectional drawing of a pipe terminal joint. It is a figure explaining the process of connecting and fixing a fluid transfer pipe to the pipe hole of a pipe terminal joint, and is a figure showing the state where the fluid transfer pipe was passed through the pipe hole of a pipe terminal joint. It is a figure explaining the process of connecting and fixing a fluid transfer pipe to the pipe hole of a pipe end joint, and is a figure showing the state where the punch was press-fitted in the fluid transfer pipe. It is a figure explaining the process which connects and fixes a fluid transfer pipe to the pipe hole of a pipe terminal joint, and is another figure which shows the state which press-fitted the punch in the fluid transfer pipe. It is a figure explaining the process which connects and fixes a fluid transfer pipe to the pipe hole of a pipe terminal joint, and is a figure which shows the state which performed the taper part. It is a figure explaining the process which connects and fixes a fluid transfer pipe to the pipe hole of a pipe terminal joint, and is a figure showing the state where the seal slot was formed in the tip part of the fluid transfer pipe. It is a comparison figure with the case where the back side retaining bulge part is formed.

Explanation of symbols

1 Pipe end fitting
3 Flange 5 Mounting portion 9 Pipe hole 13 Clearance (engagement groove)
17 Convex part 23 Engaging concave part 25 Fluid transfer pipe

Claims (6)

A flange having an attachment portion and a pipe hole is formed, and the end portion side of the fluid transfer pipe is inserted into and fixed to the pipe hole, and the attachment portion is fixed to the connected side to which the fluid transfer pipe is connected. A pipe end fitting,
In the pipe hole, a plurality of protrusions for rotation prevention are formed with a gap in the circumferential direction, an engagement groove is formed between the adjacent protrusions ,
The convex portion is formed at an axially intermediate portion of the pipe hole, and engaging concave portions are provided on both axial sides of the convex portion,
Each of both axial side surfaces of the convex portion is inclined outward in the axial direction from the radially inner side toward the base side ,
The contour shape of the radially inner surface of the convex portion is formed in a square shape, and the contour shape of the base portion of the convex portion is formed in a square shape larger than the radially inner surface of the convex portion,
A pipe end joint , wherein an axial length of the radially inner surface is greater than a thickness of the convex portion . The radially inner surface of the convex portion is curved in an arc shape along the circumferential direction, and the base portion of the convex portion has an axial length larger than the axial length of each of the engaging concave portions on both sides. The pipe end joint according to claim 1, wherein the pipe end joint is formed as follows . 3. The pipe end joint according to claim 1, wherein the bottom surface of the engagement groove and the bottom surface of the engagement recess are located on the same cylindrical surface. 4. A pipe end joint having a flange provided with an attachment portion and having a pipe hole formed therein; and a fluid transfer pipe fixed at an end side inserted into the pipe hole, to which the fluid transfer pipe is connected. A pipe terminal connection structure for fixing the attachment portion to the connection side,
In the pipe hole, a plurality of protrusions for rotation prevention are formed with a gap in the circumferential direction, an engagement groove is formed between the adjacent protrusions,
The convex portion is formed at an axially intermediate portion of the pipe hole, and engaging concave portions are provided on both axial sides of the convex portion,
Each of both axial side surfaces of the convex portion is inclined outward in the axial direction from the radially inner side toward the base side,
The contour shape of the radially inner surface of the convex portion is formed in a square shape, and the contour shape of the base portion of the convex portion is formed in a square shape larger than the radially inner surface of the convex portion,
The axial length of the radially inner surface is greater than the thickness of the convex portion,
The end side of the fluid transfer pipe is pressed from the inside, so that the outer periphery is deformed so as to follow the uneven shape of the pipe hole, and enters the engagement groove and the engagement recess .
The pipe end connection structure characterized in that an outer diameter of the fluid transfer pipe on the end side is formed around the back opening of the pipe hole and is the same as the diameter of the back opening of the pipe hole. The radially inner surface of the convex portion is curved in an arc shape along the circumferential direction, and the base portion of the convex portion has an axial length larger than the axial length of each of the engaging concave portions on both sides. The pipe terminal connection structure according to claim 4, wherein the pipe terminal connection structure is formed. The pipe end connection structure according to claim 4 or 5, wherein the bottom surface of the engagement groove and the bottom surface of the engagement recess are located on the same cylindrical surface.

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