Pipe structures and pipe fittings

Abstract

To provide a pipe structure and pipe joint that reduces the number of parts and allows for easy disassembly and connection of the inner and outer pipes. [Solution] The pipe structure 1 comprises an inner pipe 10, an outer pipe 20 that forms an annular insertion gap between itself and the inner pipe 10, and a pipe joint 30 that connects the inner pipe 10 and the outer pipe 20. The pipe joint 30 comprises a first sleeve member 40 having a groove 42 filled with liquid L on its end face 41 opposite to the insertion direction D of the inner pipe 10 relative to the outer pipe 20, a second sleeve member 50 having a projection 52 that protrudes toward the first sleeve member 40 on its end face 51 on the insertion direction D side, and a fastening means 60 that fastens the second sleeve member 50 to the first sleeve member 40 such that the projection 52 presses the liquid L in the groove 42. The groove 42 is provided at a position eccentrically inward in the radial direction from the fastening position where the second sleeve member 50 is fastened to the first sleeve member 40.

Description

Technical Field

[0001] The present disclosure relates to a pipe structure and a pipe joint.

Background Art

[0002] As a pipe joint for connecting two pipes, Patent Document 1 discloses a pipe joint for connecting cylindrical pipes having substantially the same shape. This pipe joint is cylindrical with an inner diameter larger than the outer diameter of the pipe, and has an outer sleeve member having an end portion into which the end portion of the pipe is inserted, and is cylindrical with an inner diameter smaller than the outer diameter of the pipe. By being attached to the outer periphery of the end portion of the pipe, it expands in diameter and is arranged in the gap between the outer periphery of the end portion of the pipe and the inner periphery of the end portion of the outer sleeve member. A pair of elastic seal members having an annular lip portion and an annular protruding portion that abuts against the end face of the end portion of the outer sleeve member, and fixing means for pressing and fixing the annular protruding portion of the elastic seal member against the end face of the end portion of the outer sleeve member.

[0003] Patent Document 1 describes that by pressing and fixing the annular protruding portion of the elastic seal member against the end face of the end portion of the outer sleeve member, two pipes can be connected by the pipe joint without performing special processing such as welding or threading.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technique described in Patent Document 1, since the elastic seal member is a separate part from the outer sleeve member and the two pipes, the number of parts increases, and there is a problem that the work of assembling these parts to connect the pipes becomes complicated.

[0006] This disclosure is made to solve such problems and aims to provide a pipe structure and pipe joint that reduces the number of parts and allows for easy disassembly and connection of the inner and outer pipes. [Means for solving the problem]

[0007] A pipe structure according to one embodiment includes an inner pipe, an outer pipe including an end into which the end of the inner pipe is inserted inward, forming an annular insertion gap between the outer pipe and the outer pipe, and a pipe joint into which the end of the outer pipe is inserted inward, connecting the inner pipe and the outer pipe. The pipe joint includes a first sleeve member having a groove filled with liquid on the end face opposite to the insertion direction of the inner pipe relative to the outer pipe, a second sleeve member having a projection on the end face on the insertion direction side that projects toward the first sleeve member, and fastening means for fastening the second sleeve member to the first sleeve member such that the projection presses the liquid in the groove. The groove is provided at a position eccentrically inward in the radial direction of the first sleeve member from the fastening position on the first sleeve member to which the second sleeve member is fastened by the fastening means.

[0008] A pipe joint according to one embodiment connects an inner pipe and an outer pipe, with the end of the outer pipe being inserted into the inner pipe and the end of the outer pipe being inserted into the inner pipe, forming an annular insertion gap between the outer pipe and the outer pipe. The pipe joint comprises a first sleeve member having a groove filled with liquid on the end face opposite to the insertion direction of the inner pipe relative to the outer pipe, a second sleeve member having a projection that protrudes toward the first sleeve member on the end face on the insertion direction side, and fastening means for fastening the second sleeve member to the first sleeve member such that the projection presses the liquid in the groove, wherein the groove is provided at a position eccentrically inward in the radial direction of the first sleeve member from the fastening position on the first sleeve member to which the second sleeve member is fastened by the fastening means. [Effects of the Invention]

[0009] This disclosure makes it possible to provide a pipe structure and pipe joint that reduces the number of parts and allows for easy disassembly and connection of the inner pipe and outer pipe. [Brief explanation of the drawing]

[0010] [Figure 1] This is a diagram showing the configuration of the pipe structure according to Embodiment 1. [Figure 2] This diagram shows the configuration of the pipe joint according to Embodiment 1. [Figure 3] This is a cross-sectional view illustrating the first step of inserting the end of the inner pipe into the inside of the end of the outer pipe. [Figure 4] This is a cross-sectional view illustrating the second step, in which the inner pipe and outer pipe are connected using pipe fittings after the first step. [Modes for carrying out the invention]

[0011] Embodiment 1 Embodiments of this disclosure will be described below with reference to the drawings. However, this disclosure is not limited to the embodiments described below. Also, for clarity, the following description and drawings have been simplified as appropriate.

[0012] In the following explanation, the axial direction along the central axis O is defined as the X direction, the radial direction is the direction that intersects (is perpendicular to) the central axis O, and the circumferential direction is the direction that rotates around the central axis O. The axial, radial, and circumferential directions of the inner pipe 10 and the outer pipe 20 coincide with the axial, radial, and circumferential directions of the first sleeve member 40 and the second sleeve member 50. The Y direction shown in the figure corresponds to the radial direction, and the Z direction shown in the figure corresponds to the circumferential direction. In addition, the insertion direction D of the inner pipe 10 relative to the outer pipe 20 is indicated by a white arrow in the figure. The insertion direction D is the direction from the other side to the one side in the X direction.

[0013] Figure 1 shows the configuration of a pipe structure according to Embodiment 1. Figure 1 shows a plan view of the pipe structure 1 as seen from the other side in the X direction, and a cross-sectional view of the pipe structure 1 as seen from one side in the radial direction. The pipe structure 1 shown in Figure 1 can be applied to the frame of a vehicle such as an automobile.

[0014] As shown in Figure 1, the pipe structure 1 includes an inner pipe 10, an outer pipe 20, and a pipe joint 30. The inner pipe 10 and the outer pipe 20 are two pipes with different diameters. The material of the inner pipe 10 and the outer pipe 20 is, for example, a metal such as steel. The inner pipe 10 and the outer pipe 20 extend along the X direction.

[0015] The inner pipe 10 is formed in a cylindrical shape with an outer diameter smaller than the inner diameter of the outer pipe 20. The inner pipe 10 includes an end 11 that is inserted into the end 21 of the outer pipe 20. The end 11 is located on one side of the inner pipe 10 in the X direction. The outer pipe 20 is formed in a cylindrical shape with an inner diameter larger than the outer diameter of the inner pipe 10. The outer pipe 20 includes an end 21 into which the end 11 of the inner pipe 10 is inserted, forming an annular insertion gap G (see Figure 3) between it and the inner pipe 10. The end 21 is located on the other side of the outer pipe 20 in the X direction.

[0016] The pipe joint 30 connects the inner pipe 10 and the outer pipe 20 by inserting the end 21 of the outer pipe 20 into the inner pipe 30. The pipe joint 30 includes a first sleeve member 40, a second sleeve member 50, and fastening means 60. The material of the first sleeve member 40 and the second sleeve member 50 is, for example, a metal such as steel.

[0017] The first sleeve member 40 is formed in a cylindrical shape having an inner diameter slightly larger than the outer diameter of the outer pipe 20. The first sleeve member 40 has a groove 42 filled with liquid L on the end face 41 opposite to the insertion direction D of the inner pipe 10 relative to the outer pipe 20. For example, machine oil can be used as the liquid L.

[0018] The second sleeve member 50 is formed in a disc shape having an inner diameter slightly larger than the outer diameter of the outer pipe 20. The second sleeve member 50 is provided with a protruding portion 52 protruding toward the first sleeve member 40 on an end surface 51 on the insertion direction D side of the inner pipe 10 with respect to the outer pipe 20. The protruding portion 52 can be fitted to an end portion on the other end side in the X direction of the groove portion 42.

[0019] The first sleeve member 40 and the second sleeve member 50 are externally fitted to the end portion 21 of the outer pipe 20 while the end surfaces 41 and 51 face each other in the X direction.

[0020] The fastening means 60 fastens the second sleeve member 50 to the first sleeve member 40 so that the protruding portion 52 presses the liquid L in the groove portion 42. The groove portion 42 is provided at a position eccentric in the radial direction of the first sleeve member 40 from the fastening position in the first sleeve member 40 to which the second sleeve member 50 is fastened by the fastening means 60.

[0021] In the present embodiment, the protruding portion 52 presses the liquid L in the groove portion 42 by using the fastening force of the fastening means 60 when fastening the second sleeve member 50 to the first sleeve member 40, so that the liquid L is compressed. Then, due to the hydraulic pressure acting in the insertion direction D of the compressed liquid L, the first sleeve member 40 is displaced by elastic deformation in the radial direction. As a result, since the first sleeve member 40 applies a fastening force radially inward to the inner pipe 10 and the outer pipe 20, the pipe joint 30 can fill the insertion gap G and connect the inner pipe 10 and the outer pipe 20.

[0022] Further, the hydraulic pressure of the liquid L compressed as described above is uniformly transmitted to the first sleeve member 40 without changing in magnitude according to Pascal's principle. Therefore, in the present embodiment, the groove portion 42 is provided at a position eccentric from the above-described fastening position toward the radially inner side of the first sleeve member 40. As a result, the first sleeve member 40 to which the hydraulic pressure of the compressed liquid L is transmitted is displaced more greatly toward the radially inner side than toward the radially outer side, so that the first sleeve member 40 can be displaced greatly toward the radially inner side with a smaller hydraulic pressure. Therefore, according to the present embodiment, it is possible to easily disassemble and connect the inner pipe 10 and the outer pipe 20.

[0023] In the present embodiment, a liquid L that generates a fastening force for fastening the inner pipe 10 and the outer pipe 20 by fastening the second sleeve member 50 to the first sleeve member 40 by the fastening means 60 is enclosed in the groove portion 42 of the first sleeve member 40. Therefore, the pipe structure 1 and the pipe joint 30 according to the present embodiment enable connection and disassembly of the inner pipe 10 and the outer pipe 20 with a small number of parts.

[0024] As described above, according to the present embodiment, it is possible to provide the pipe structure 1 and the pipe joint 30 that can be easily connected and disassembled between the inner pipe 10 and the outer pipe 20 while reducing the number of parts.

[0025] In the pipe structure 1 described above, the fastening means 60 preferably includes a bolt hole 61 penetrating the second sleeve member 50, a bolt member 62 inserted into the bolt hole 61 along the insertion direction D, and a screw hole 63 formed in the end face 41 of the first sleeve member 40 and screwed with the bolt member 62.

[0026] According to such a configuration, the protruding portion 52 of the second sleeve member 50 can easily press the liquid L in the groove portion 42 of the first sleeve member 40 by the axial force (fastening force) of the bolt member 62 that fastens the second sleeve member 50 to the first sleeve member 40 by screwing it into the screw hole 63. Therefore, it is possible to easily connect and disassemble the inner pipe 10 and the outer pipe 20.

[0027] Here, Figure 2 shows the configuration of the pipe joint according to Embodiment 1. Figure 2 shows a plan view of the pipe joint 30 as seen from the other side in the X direction, and a cross-sectional view of the pipe joint 30 as seen from one side in the radial direction.

[0028] As shown in Figure 2, the multiple screw holes 63 are arranged at predetermined intervals from each other in the circumferential direction. The screw holes 63 are recessed into one side in the X direction from the end face 41 of the first sleeve member 40. The multiple bolt holes 61 into which the bolt members 62 are each inserted are arranged at predetermined intervals from each other in the circumferential direction so as to overlap with the multiple screw holes 63 in the X direction. The bolt holes 61 are holes that penetrate the second sleeve member 50 in the X direction. The bolt members 62 are inserted into the bolt holes 61 formed in the second sleeve member 50 and detachably screwed into the screw holes 63 formed in the end face 41 of the first sleeve member 40.

[0029] In this embodiment, the pipe joint 30 has a configuration in which four screw holes 63 and four bolt holes 61 overlapping these in the X direction are arranged at 90° intervals in the circumferential direction, from the viewpoint of improving fastening performance while reducing costs, but it is not limited to this configuration. For example, the pipe joint 30 may have a configuration in which two screw holes 63 and two bolt holes 61 overlapping these in the X direction are arranged at 180° intervals in the circumferential direction, a configuration in which eight screw holes 63 and eight bolt holes 61 overlapping these in the X direction are arranged at 45° intervals in the circumferential direction, or a configuration in which sixteen screw holes 63 and sixteen bolt holes 61 overlapping these in the X direction are arranged at 22.5° intervals in the circumferential direction.

[0030] Furthermore, in the pipe structure 1 described above, it is preferable that the groove 42 and the protrusion 52 each extend in an annular shape.

[0031] With this configuration, the protrusion 52 of the second sleeve member 50 can easily press against the liquid L in the groove 42 of the first sleeve member 40. Therefore, the connection and disconnection of the inner pipe 10 and the outer pipe 20 can be easily performed.

[0032] In this embodiment, the pipe joint 30 is configured to reduce costs by having one groove 42 extending annularly along the circumferential direction and one projection 52 extending annularly along the circumferential direction so as to overlap with it in the X direction. However, it is not limited to this configuration. For example, the pipe joint 30 may be configured in which the groove 42 is divided into a plurality of parts (e.g., four) and the projection 52 is divided into a plurality of parts so as to overlap with these in the X direction, each arranged at predetermined intervals along the circumferential direction.

[0033] As shown in Figure 1, in the pipe structure 1 described above, it is preferable that the outer pipe 20 has a positioning portion 22 for positioning the first sleeve member 40.

[0034] With this configuration, when connecting the inner pipe 10 and the outer pipe 20 with the pipe joint 30, misalignment of the pipe joint 30 relative to the outer pipe 20 can be suppressed.

[0035] In this embodiment, the positioning portion 22 is a portion that protrudes radially outward from the outer circumferential surface of the outer pipe 20. The positioning portion 22 extends in an annular shape on the outer circumferential surface of the outer pipe 20. Such a positioning portion 22 can be provided at a predetermined position on the outer circumferential surface of the outer pipe 20.

[0036] Here, with reference to Figures 3 and 4, the procedure for connecting the inner pipe 10 and the outer pipe 20 using a pipe fitting 30 will be explained. Figure 3 is a cross-sectional view illustrating the first step of inserting the end of the inner pipe into the inside of the end of the outer pipe. Figure 4 is a cross-sectional view illustrating the second step of connecting the inner pipe and the outer pipe after the first step using a pipe fitting.

[0037] As shown in Figures 3 and 4, the procedure for connecting the inner pipe 10 and the outer pipe 20 with a pipe joint 30 includes a first step of inserting the end 11 of the inner pipe 10 into the inside of the end 21 of the outer pipe 20, and a second step of connecting the inner pipe 10 and the outer pipe 20 after the first step with the pipe joint 30.

[0038] In the first step, as shown in Figure 3, the end 11 of the inner pipe 10 is first inserted into the inside of the end 21 of the outer pipe 20 from the other side in the X direction. As a result, the ends 11 and 21 of the inner pipe 10 and the outer pipe 20 overlap radially, and the inner pipe 10 and the outer pipe 20 are arranged coaxially with their respective central axes coinciding through the insertion gap G between them.

[0039] Here, if there is no insertion gap G, the inner pipe 10 and the outer pipe 20 will collide, and there is a risk that the end 11 of the inner pipe 10 will not be able to be inserted inside the end 21 of the outer pipe 20. On the other hand, if the insertion gap G is too large, there is a risk that the inner pipe 10 may come off the outer pipe 20 after the inner pipe 10 and the outer pipe 20 are connected, or that it may become a source of noise and vibration (NV).

[0040] Therefore, the insertion gap G is preferably 0.05 mm or more and 1 mm or less. If the insertion gap G is 0.05 mm or more, the end 11 of the inner pipe 10 can be suitably inserted inside the end 21 of the outer pipe 20. If the insertion gap G is 1 mm or less, it is possible to prevent the inner pipe 10 from coming off the outer pipe 20 or becoming a source of noise after the inner pipe 10 and outer pipe 20 are connected.

[0041] Next, in the second step, as shown in Figure 4, first, the end 21 of the outer pipe 20, after the end 11 of the inner pipe 10 has been inserted, is inserted into the inside of the first sleeve member 40 from the other side in the X direction, so that the first sleeve member 40 is positioned to abut against the positioning portion 22 of the outer pipe 20.

[0042] Subsequently, when the end 21 of the outer pipe 20 is inserted into the second sleeve member 50 from the other side in the X direction, the second sleeve member 50 is positioned to abut against the first sleeve member 40. As a result, the inner pipe 10, the outer pipe 20, the first sleeve member 40, and the second sleeve member 50 are assembled and arranged coaxially so that their respective central axes coincide.

[0043] Subsequently, the bolt member 62 inserted into the bolt hole 61 of the second sleeve member 50 is screwed into the threaded hole 63 of the first sleeve member 40, thereby fastening the second sleeve member 50 to the first sleeve member 40. At the same time, the liquid L in the groove 42 of the first sleeve member 40 is pressurized and compressed by the axial force of the bolt member 62. As the first sleeve member 40 elastically deforms due to the pressurized liquid L, the insertion gap G is filled, and the inner pipe 10 and the outer pipe 20 are connected.

[0044] On the other hand, the procedure for disassembling the inner pipe 10 and the outer pipe 20 connected by the pipe joint 30 is the reverse of the procedure for connecting the inner pipe 10 and the outer pipe 20 with the pipe joint 30 described above.

[0045] Specifically, when the bolt member 62 is loosened, the liquid pressure of the liquid L in the groove 42 of the first sleeve member 40 is reduced. Then, due to the reduced liquid pressure of the liquid L, the first sleeve member 40 elastically deforms, forming an insertion gap G between the inner pipe 10 and the outer pipe 20. Furthermore, after removing the pipe fitting 30 fitted onto the end 21 of the outer pipe 20 from the outer pipe 20, the inner pipe 10 is removed from the outer pipe 20, resulting in the inner pipe 10 and the outer pipe 20 being separated.

[0046] By the way, for example, if the inner pipe 10 and the outer pipe 20 are connected by welding or adhesive, it is difficult to disassemble them into the inner pipe 10 and the outer pipe 20 after the connection.

[0047] In contrast, the pipe structure 1 according to this embodiment is formed by connecting the inner pipe 10 and the outer pipe 20 with a pipe joint 30, so that the inner pipe 10 and the outer pipe 20 can be reversibly connected and disconnected.

[0048] Furthermore, for example, if the inner pipe 10 and the outer pipe 20 are connected by adhesive bonding, if moisture such as rain or mud comes into contact with the connection between the inner pipe 10 and the outer pipe 20, the adhesive can be easily hydrolyzed by the moisture. If the adhesive at the connection point peels off due to hydrolysis, there is a risk that the inner pipe 10 may detach from the outer pipe 20 or that it may become a source of NV (noise pollution).

[0049] In contrast, the pipe structure 1 according to this embodiment connects the inner pipe 10 and the outer pipe 20 by a pipe joint 30 without using adhesive, and prevents the inner pipe 10 from coming off the outer pipe 20 or becoming a source of noise after the inner pipe 10 and the outer pipe 20 are connected.

[0050] This disclosure is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. For example, the pipe structure 1 can be applied not only to vehicle frame members, but also to shafts such as drive shafts and instrument panel reinforcements, and to parts of infrastructure such as scaffolding at construction sites and bridges.

[0051] Furthermore, the materials of the inner pipe 10, outer pipe 20, first sleeve member 40, and second sleeve member 50 are not limited to steel, but may be metals such as aluminum or titanium, or alloys such as aluminum alloys or titanium alloys. Also, the materials of the inner pipe 10, outer pipe 20, first sleeve member 40, and second sleeve member 50 are not limited to metal, but may be resins such as polyvinyl chloride or polycarbonate. The materials of the inner pipe 10, outer pipe 20, first sleeve member 40, and second sleeve member 50 should be such that at least the first sleeve member 40 can be elastically deformed by the hydraulic pressure acting in the insertion direction D of the compressed liquid L. Furthermore, the inner pipe 10, outer pipe 20, first sleeve member 40, and second sleeve member 50 may be made of different materials or the same material.

[0052] Furthermore, in the above embodiment, an example was shown in which machine oil was used as liquid L from the viewpoint of preventing rust on steel, being viscous and less likely to leak, and being inexpensive. However, liquid L is not limited to machine oil; for example, water (e.g., pure water), an aqueous solvent mainly composed of water, a non-aqueous solvent (e.g., ethanol), etc., can be used.

[0053] Furthermore, in the above embodiment, the second sleeve member 50 is fastened to the first sleeve member 40 by a bolt member 62, but the embodiment is not limited to this, and for example, the second sleeve member 50 may be fastened to the first sleeve member 40 by a combination of a bolt and a nut.

[0054] Furthermore, for example, in order to suppress leakage of liquid L from the groove 42 of the first sleeve member 40, a coating capable of suppressing leakage of liquid L from the groove 42 of the first sleeve member 40 may be applied to at least one of the groove 42 and the protrusion 52, or a sealing member capable of suppressing leakage of liquid L from the groove 42 of the first sleeve member 40 may be interposed between the groove 42 and the protrusion 52. The coating may be formed of a water-repellent material if the liquid L is water-soluble, or of an oil-repellent material if the liquid L is lipophilic. The sealing member may be formed of a rubber material, for example. [Explanation of Symbols]

[0055] 1. Pipe structure 10 Inner pipe 11 End 20 Outer pipe 21 End portion 22 Positioning portion 30 Pipe Fittings 40 First sleeve member 41 End face 42 Groove 50 Second sleeve member 51 End face 52 Protrusion 60 Fastening means 61 Bolt hole 62 Bolt member 63 Threaded hole D: Insertion direction L: Liquid G: Insertion gap O: Central axis

Claims

1. The inner pipe and The outer pipe includes an end of the inner pipe that is inserted inward, and forms an annular insertion gap between itself and the inner pipe, The end of the outer pipe is inserted inward, and a pipe joint connects the inner pipe and the outer pipe, The aforementioned pipe joint is, A first sleeve member having a groove filled with liquid on the end face opposite to the insertion direction of the inner pipe relative to the outer pipe, A second sleeve member having a protrusion on its end face on the insertion direction side that protrudes toward the first sleeve member, The system includes fastening means for fastening the second sleeve member to the first sleeve member such that the protruding portion presses against the liquid in the groove, The groove portion is a pipe structure provided at a position eccentrically inward in the radial direction of the first sleeve member from the fastening position on the first sleeve member where the second sleeve member is fastened by the fastening means.

2. The pipe structure according to claim 1, wherein the fastening means comprises a bolt hole penetrating the second sleeve member, a bolt member inserted into the bolt hole along the insertion direction, and a screw hole formed on the end face of the first sleeve member into which the bolt member is screwed.

3. The pipe structure according to claim 1, wherein the groove and the protrusion each extend in an annular shape.

4. The pipe structure according to claim 1, wherein the outer pipe has a positioning portion for positioning the first sleeve member.

5. A pipe fitting connecting an inner pipe and an outer pipe, wherein the end of the inner pipe includes an end that is inserted inward, and the end of the outer pipe, which forms an annular insertion gap between itself and the inner pipe, is inserted inward, A first sleeve member having a groove filled with liquid on the end face opposite to the insertion direction of the inner pipe relative to the outer pipe, A second sleeve member having a protrusion on its end face on the insertion direction side that protrudes toward the first sleeve member, The system includes fastening means for fastening the second sleeve member to the first sleeve member such that the protruding portion presses against the liquid in the groove, The groove portion is a pipe joint provided at a position eccentrically inward in the radial direction of the first sleeve member from the fastening position on the first sleeve member where the second sleeve member is fastened by the fastening means.

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