Pipe structure and pipe joint

Abstract

The invention provides a pipe structure and a pipe joint which can reduce the number of parts and can easily separate and connect an inner pipe and an outer pipe. The duct structure includes: an inner duct; an outer duct forming an annular insertion gap between the outer duct and the inner duct; and a pipe joint for connecting the inner pipe and the outer pipe, the pipe joint having: a first sleeve member provided with a groove portion in which a liquid is sealed on an end surface on the opposite side of the insertion direction of the inner pipe with respect to the outer pipe; a second sleeve member provided with a protruding portion protruding toward the first sleeve member on an end surface on the insertion direction side; and a fastening mechanism that fastens the second sleeve member to the first sleeve member such that the protruding portion presses the liquid in the groove portion, and the groove portion is provided at a position eccentric from a fastening position at which the second sleeve member is fastened toward the inside in the radial direction of the first sleeve member.

Description

Technical Field

[0001] This invention relates to a pipe structure and a pipe fitting. Background Technology

[0002] As a pipe fitting for connecting two pipes, Patent Document 1 discloses a pipe fitting for connecting cylindrical pipes having substantially the same shape. This pipe fitting is characterized by having: an outer sleeve component, which is cylindrical with an inner diameter larger than the outer diameter of the pipe and has an end for insertion into the pipe end; a pair of resilient sealing components, which are cylindrical with an inner diameter smaller than the outer diameter of the pipe, and are enlarged by being installed on the outer periphery of the pipe end, the resilient sealing components having: an annular lip disposed in the gap between the outer periphery of the pipe end and the inner periphery of the outer sleeve component end; and an annular protrusion abutting against the end face of the outer sleeve component; and a fixing mechanism for pressing and fixing the annular protrusion of the resilient sealing component to the end face of the outer sleeve component.

[0003] Patent document 1 describes the following: the two pipes are connected by a pipe joint by pressing and fixing the annular protrusion of the elastic sealing component to the end face of the outer sleeve component, without the need for special processing such as welding or tapping.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2005-201414 Summary of the Invention

[0005] However, in the technology described in Patent Document 1, the elastic sealing component is a different part from the outer sleeve component and the two pipes. Therefore, the number of parts increases, and the operation of assembling these parts to connect the pipes to each other becomes cumbersome.

[0006] This invention was made to solve this problem, and its purpose is to provide a pipe structure and pipe fitting that reduces the number of parts and allows for easy disassembly and connection of the inner and outer pipes.

[0007] One embodiment of the pipe structure includes: an inner pipe; an outer pipe, including an end of the inner pipe inserted into the inner pipe and forming an annular insertion gap between the outer pipe and the inner pipe; and a pipe joint, which is inserted into the inner pipe and connects the inner pipe and the outer pipe. The pipe joint includes: a first sleeve component, which has a groove filled with liquid on its end face opposite to the insertion direction of the inner pipe relative to the outer pipe; a second sleeve component, which has a protrusion protruding into the first sleeve component on its end face in the insertion direction; and a fastening mechanism that fastens the second sleeve component to the first sleeve component by pressing the protrusion against the liquid in the groove. The groove is located at a position eccentric to the radially inward side of the first sleeve component from the fastening position in which the second sleeve component is fastened by the fastening mechanism.

[0008] One embodiment of the pipe fitting includes an end of an inner pipe inserted into an inner end, and an end of an outer pipe forming an annular insertion gap with the inner pipe inserted into the inner end, connecting the inner and outer pipes. The pipe fitting has: a first sleeve component having a groove filled with liquid on its end face opposite to the insertion direction of the inner pipe relative to the outer pipe; a second sleeve component having a protrusion protruding into the first sleeve component on its end face in the insertion direction; and a fastening mechanism that fastens the second sleeve component to the first sleeve component by pressing the protrusion against the liquid in the groove, wherein the groove is located radially inwardly eccentrically from the fastening position in the first sleeve component where the second sleeve component is fastened by the fastening mechanism.

[0009] Invention Effects

[0010] This invention provides a pipe structure and pipe fitting that reduces the number of parts and allows for easy disassembly and connection of the inner and outer pipes. Attached Figure Description

[0011] Figure 1 This is a diagram showing the structure of the pipe structure involved in Embodiment 1.

[0012] Figure 2 This is a diagram showing the structure of the pipe fitting involved in Embodiment 1.

[0013] 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.

[0014] Figure 4 This is a cross-sectional view illustrating the second process, where the inner and outer pipes are connected via pipe fittings after the first process. Detailed Implementation

[0015] Implementation Method 1

[0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to these embodiments. Furthermore, for clarity, the following description and drawings are appropriately simplified.

[0017] In the following description, the axial direction along the central axis O is defined as the X direction; the radial direction, centered on the central axis O and intersecting (orthogonal) to the central axis O, is defined as the radial direction; and the circumferential direction, centered on the central axis O and axially aligned with the central axis O, is defined as the circumferential direction. The axial, radial, and circumferential directions of the inner pipe 10 and the outer pipe 20 are consistent with the axial, radial, and circumferential directions of the first sleeve component 40 and the second sleeve component 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. Furthermore, in the figure, a hollow arrow indicates the insertion direction D of the inner pipe 10 relative to the outer pipe 20. The insertion direction D is the direction from the other side of the X direction toward one side.

[0018] Figure 1 This is a diagram showing the structure of the pipe structure involved in Embodiment 1. Figure 1 The diagram shows a top view of the pipe structure 1 as viewed from the other side in the X direction and a cross-sectional view of the pipe structure 1 as viewed from the radial side. Figure 1 The pipe structure 1 shown can be applied to the frame components of vehicles such as automobiles.

[0019] like Figure 1 As shown, the pipe structure 1 has an inner pipe 10, an outer pipe 20, and a pipe fitting 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.

[0020] The inner conduit 10 is formed as a cylinder with an outer diameter smaller than the inner diameter of the outer conduit 20. The inner conduit 10 includes an end 11 that is inserted into the end 21 of the outer conduit 20. The end 11 is disposed on one side of the inner conduit 10 in the X direction. The outer conduit 20 is formed as a cylinder with an inner diameter larger than the outer diameter of the inner conduit 10. The outer conduit 20 includes an end 21 of the end 11 of the inner conduit 10 that is inserted inwardly, and an annular insertion gap G is formed between the outer conduit 20 and the inner conduit 10 (see reference). Figure 3 End 21 is located on the other side of the outer pipe 20 in the X direction.

[0021] The pipe fitting 30 allows the end 21 of the outer pipe 20 to be inserted into the inner side, connecting the inner pipe 10 and the outer pipe 20. The pipe fitting 30 has a first sleeve component 40, a second sleeve component 50, and a fastening mechanism 60. The first sleeve component 40 and the second sleeve component 50 are made of metals such as steel.

[0022] The first sleeve component 40 is formed as a cylinder with an inner diameter slightly larger than the outer diameter of the outer pipe 20. The first sleeve component 40 has a groove 42 for sealing liquid L on its end face 41, which is opposite to the insertion direction D of the inner pipe 10 of the outer pipe 20. For example, machine oil can be used as the liquid L.

[0023] The second sleeve component 50 is formed as a circular plate with an inner diameter slightly larger than the outer diameter of the outer pipe 20. The second sleeve component 50 has a protrusion 52 on its end face 51 on the insertion direction D side of the inner pipe 10 relative to the outer pipe 20, protruding toward the first sleeve component 40. The protrusion 52 can be fitted into the end of the groove 42 on the other end side in the X direction.

[0024] The end faces 41 and 51 of the first sleeve component 40 and the second sleeve component 50 are opposite each other in the X direction and are externally embedded in the end 21 of the outer pipe 20.

[0025] The fastening mechanism 60 fastens the second sleeve component 50 to the first sleeve component 40 by pressing the protrusion 52 against the liquid L in the groove 42. Furthermore, the groove 42 is located radially inward from the fastening position in the first sleeve component 40 where the second sleeve component 50 is fastened by the fastening mechanism 60.

[0026] In this embodiment, the protrusion 52 presses against the liquid L in the groove 42 by the fastening force of the fastening mechanism 60 when the second sleeve component 50 is fastened to the first sleeve component 40, thereby compressing the liquid L. Furthermore, the first sleeve component 40 is displaced radially by the hydraulic pressure exerted by the compressed liquid L in the insertion direction D, due to elastic deformation. As a result, the first sleeve component 40 applies a radially inward fastening force to the inner pipe 10 and the outer pipe 20, thus enabling the pipe joint 30 to block the insertion gap G and connect the inner pipe 10 and the outer pipe 20.

[0027] Furthermore, the hydraulic pressure of the compressed liquid L, as described above, is uniformly transmitted to the first sleeve component 40 with constant magnitude through Pascal's principle. Therefore, in this embodiment, the groove 42 is positioned eccentrically to the radially inward side from the aforementioned fastening position towards the first sleeve component 40. Consequently, the first sleeve component 40, which transmits the hydraulic pressure of the compressed liquid L, is displaced radially inward more than radially outward, thus allowing for a greater radially inward displacement of the first sleeve component 40 with a smaller hydraulic pressure. Therefore, according to this embodiment, the inner pipe 10 and the outer pipe 20 can be easily disassembled and connected.

[0028] In this embodiment, the second sleeve component 50 is fastened to the first sleeve component 40 by the fastening mechanism 60, thereby generating a fastening force for fastening the inner pipe 10 and the outer pipe 20, and the liquid L is sealed into the groove 42 of the first sleeve component 40. Therefore, the pipe structure 1 and pipe joint 30 according to this embodiment can connect and disconnect the inner pipe 10 and the outer pipe 20 with a smaller number of parts.

[0029] Thus, according to this embodiment, a pipe structure 1 and pipe joint 30 with reduced number of parts and easy connection and disassembly of the inner pipe 10 and the outer pipe 20 can be provided.

[0030] In the above-mentioned pipe structure 1, the fastening mechanism 60 preferably has: a bolt hole 61 penetrating the second sleeve component 50; a bolt component 62 inserted into the bolt hole 61 along the insertion direction D; and a threaded hole 63 formed on the end face 41 of the first sleeve component 40 and engaged with the bolt component 62.

[0031] According to this structure, by means of the axial force (tightening force) of the bolt member 62 that fastens the second sleeve member 50 to the first sleeve member 40 through screwing into the threaded hole 63, the protrusion 52 of the second sleeve member 50 can easily press the liquid L in the groove 42 of the first sleeve member 40. Therefore, the inner pipe 10 and the outer pipe 20 can be easily connected and disconnected.

[0032] Here, Figure 2 This is a diagram showing the structure of the pipe fitting according to Embodiment 1. Figure 2 The image shows a top view of the pipe fitting 30 viewed from the other side in the X direction and a cross-sectional view of the pipe fitting 30 viewed from the radial side.

[0033] like Figure 2 As shown, a plurality of threaded holes 63 are arranged at predetermined intervals in the circumferential direction. Each threaded hole 63 is a recessed hole extending from the end face 41 of the first sleeve member 40 towards the X direction. A plurality of bolt members 62 are respectively inserted into a plurality of bolt holes 61, which are arranged at predetermined intervals in the circumferential direction to overlap with the plurality of threaded holes 63 in the X direction. Each bolt hole 61 is a hole penetrating the second sleeve member 50 in the X direction. Bolt members 62 are inserted into bolt holes 61 formed in the second sleeve member 50 and are detachably screwed into threaded holes 63 formed in the end face 41 of the first sleeve member 40.

[0034] In this embodiment, from the viewpoint of reducing costs and improving fastening performance, the pipe fitting 30 has a structure with four threaded holes 63 and these four bolt holes 61 overlapping in the X direction arranged at 90° intervals in the circumferential direction, but it is not limited to this. For example, the pipe fitting 30 may have a structure with two threaded holes 63 and these two bolt holes 61 overlapping in the X direction arranged at 180° intervals in the circumferential direction, a structure with eight threaded holes 63 and these eight bolt holes 61 overlapping in the X direction arranged at 45° intervals in the circumferential direction, a structure with 16 threaded holes 63 and these 16 bolt holes 61 overlapping in the X direction arranged at 22.5° intervals in the circumferential direction, etc.

[0035] Furthermore, in the aforementioned pipe structure 1, the groove 42 and the protrusion 52 are preferably extended in annular shape.

[0036] With this structure, the protrusion 52 of the second sleeve component 50 can easily press the liquid L in the groove 42 of the first sleeve component 40. Therefore, the inner pipe 10 and the outer pipe 20 can be easily connected and disconnected.

[0037] In this embodiment, from the viewpoint of reducing costs, the pipe connector 30 is configured with a groove 42 extending in a circumferential ring and a protrusion 52 extending in a circumferential ring in a manner overlapping the groove 42 in the X direction. However, it is not limited to this. For example, the pipe connector 30 may be configured with the groove 42 divided into four or more parts, and the protrusion 52 overlapping the groove 42 in the X direction may also be divided into multiple parts, and each part may be arranged at a predetermined interval in the circumferential direction.

[0038] like Figure 1 As shown, in the above-mentioned pipe structure 1, the outer pipe 20 preferably has a positioning part 22 for positioning the first sleeve component 40.

[0039] According to this structure, when the inner pipe 10 and the outer pipe 20 are connected by the pipe joint 30, the positional displacement of the pipe joint 30 relative to the outer pipe 20 can be suppressed.

[0040] In this embodiment, the positioning part 22 is a portion that protrudes radially outward from the outer periphery of the outer pipe 20. The positioning part 22 extends in a ring shape on the outer periphery of the outer pipe 20. This positioning part 22 can be provided at a predetermined position on the outer periphery of the outer pipe 20.

[0041] Here, for reference Figure 3 and Figure 4 The sequence of connecting the inner pipe 10 and the outer pipe 20 through the pipe joint 30 will be explained. 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 4This is a cross-sectional view illustrating the second process, where the inner and outer pipes are connected via pipe fittings after the first process.

[0042] like Figure 3 and Figure 4 As shown, the sequence of connecting the inner pipe 10 and the outer pipe 20 through the pipe joint 30 includes: a first step, 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, connecting the inner pipe 10 and the outer pipe 20 after the first step through the pipe joint 30.

[0043] In the first process, such as Figure 3 As shown, firstly, the end 11 of the inner pipe 10 is inserted into the inner side of the end 21 of the outer pipe 20 from the other side in the X direction. Thus, the ends 11 and 21 of the inner pipe 10 and the outer pipe 20 overlap each other radially, and the inner pipe 10 and the outer pipe 20 are coaxially arranged with their respective central axes aligned, separated by an insertion gap G between the inner pipe 10 and the outer pipe 20.

[0044] If there is no insertion gap G, the inner pipe 10 and the outer pipe 20 will collide, and it may be impossible to insert the end 11 of the inner pipe 10 into the inside of the end 21 of the outer pipe 20. On the other hand, if the insertion gap G is too large, the inner pipe 10 may detach from the outer pipe 20 after the inner pipe 10 and the outer pipe 20 are connected, or become a source of noise and vibration (NV).

[0045] 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 properly inserted into the inside of the end 21 of the outer pipe 20. If the insertion gap G is 1 mm or less, it can prevent the inner pipe 10 from falling off the outer pipe 20 or becoming a source of NV after connecting the inner pipe 10 and the outer pipe 20.

[0046] Next, in the second process, as Figure 4 As shown, firstly, if the end 21 of the outer pipe 20, after the end 11 of the inner pipe 10 is inserted, is inserted from the other side in the X direction into the inner side of the first sleeve component 40, then the first sleeve component 40 is positioned to abut against the positioning part 22 of the outer pipe 20.

[0047] Then, if the end 21 of the outer pipe 20 is inserted into the inside of the second sleeve component 50 from the other side in the X direction, the second sleeve component 50 is positioned to abut against the first sleeve component 40. Thus, the inner pipe 10, the outer pipe 20, the first sleeve component 40, and the second sleeve component 50 are assembled and coaxially arranged with their respective central axes aligned.

[0048] Then, by screwing the bolt member 62, which is inserted into the bolt hole 61 of the second sleeve member 50, into the threaded hole 63 of the first sleeve member 40, the second sleeve member 50 is secured to the first sleeve member 40, and 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. Then, if the first sleeve member 40 elastically deforms due to the pressurized hydraulic pressure of the liquid L, the insertion gap G is blocked and the inner pipe 10 and the outer pipe 20 are connected.

[0049] On the other hand, the order in which the inner pipe 10 and the outer pipe 20 connected by the pipe joint 30 are disassembled is the reverse of the order in which the inner pipe 10 and the outer pipe 20 are connected by the pipe joint 30.

[0050] Specifically, if the bolt component 62 is loosened, the hydraulic pressure of the liquid L in the groove 42 of the first sleeve component 40 is reduced. Then, if the first sleeve component 40 elastically deforms due to the reduced hydraulic pressure of the liquid L, an insertion gap G is formed between the inner pipe 10 and the outer pipe 20. Moreover, if the pipe joint 30 externally fitted to the end 21 of the outer pipe 20 is removed from the outer pipe 20, and the inner pipe 10 is pulled out from the outer pipe 20, it is disassembled into the inner pipe 10 and the outer pipe 20.

[0051] For example, when the inner pipe 10 and the outer pipe 20 are connected by welding or bonding, it is difficult to disassemble them into the inner pipe 10 and the outer pipe 20 after the connection.

[0052] In contrast, the pipe structure 1 in this embodiment is formed by connecting the inner pipe 10 and the outer pipe 20 through the pipe joint 30, so that the inner pipe 10 and the outer pipe 20 can be reversibly connected and disconnected.

[0053] Furthermore, for example, when the inner pipe 10 and the outer pipe 20 are connected by using an adhesive, if the connection between the inner pipe 10 and the outer pipe 20 comes into contact with water such as rainwater or mud, the adhesive is easily hydrolyzed by the water. If the adhesive at the connection is peeled off due to hydrolysis, the inner pipe 10 may detach from the outer pipe 20 or become a source of NV (noise, pollution, and fumes).

[0054] In contrast, the pipe structure 1 of this embodiment can prevent the inner pipe 10 from detaching from the outer pipe 20 or becoming a source of NV after the inner pipe 10 is connected to the outer pipe 20 via the pipe joint 30 without the use of adhesive.

[0055] Furthermore, the present invention is not limited to the above-described embodiments, and appropriate modifications can be made without departing from the spirit of the invention. For example, the pipe structure 1 can be applied not only to vehicle frame components, but also to shaft components such as drive shafts or dashboard reinforcements, and to parts of infrastructure such as scaffolding or bridges at construction sites.

[0056] Furthermore, the materials of the inner pipe 10, outer pipe 20, first sleeve component 40, and second sleeve component 50 are not limited to steel; for example, they can 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 component 40, and second sleeve component 50 are not limited to metals; they can be resins such as vinyl chloride or polycarbonate. The materials of the inner pipe 10, outer pipe 20, first sleeve component 40, and second sleeve component 50 can be any material that allows at least the first sleeve component 40 to elastically deform under the hydraulic pressure exerted by the compressed liquid L in the insertion direction D. Furthermore, the inner pipe 10, outer pipe 20, first sleeve component 40, and second sleeve component 50 can be made of different materials or the same material.

[0057] Furthermore, in the above embodiments, from the viewpoint of taking into account the rust prevention of steel, its viscosity, its non-leaking properties, and its low cost, an example of using machine oil as liquid L is shown. However, liquid L is not limited to machine oil. For example, water (e.g., pure water), water-based solvents with water as the main component, and non-water-based solvents (e.g., ethanol) can be used.

[0058] Furthermore, in the above embodiment, the second sleeve component 50 is fastened to the first sleeve component 40 by the bolt component 62, but it is not limited to this method. For example, the second sleeve component 50 can also be fastened to the first sleeve component 40 by a combination of bolts and nuts.

[0059] Furthermore, for example, to prevent liquid L from leaking from the groove 42 of the first sleeve component 40, a coating capable of preventing liquid L from leaking from the groove 42 of the first sleeve component 40 can be applied to at least one of the groove 42 and the protrusion 52, or a sealing member capable of preventing liquid L from leaking from the groove 42 of the first sleeve component 40 can be inserted between the groove 42 and the protrusion 52. The coating, for example, can be formed of a hydrophobic material if the liquid L is water-soluble, and can be formed of an oleophobic material if the liquid L is oleophilic. The sealing member, for example, can be formed of a rubber material.

[0060] Symbol Explanation

[0061] 1-Pipe structure, 10-Inner pipe, 11-End, 20-Outer pipe, 21-End, 22-Positioning part, 30-Pipe fitting, 40-First sleeve component, 41-End face, 42-Groove, 50-Second sleeve component, 51-End face, 52-Protrusion, 60-Fasting mechanism, 61-Bolt hole, 62-Bolt component, 63-Threaded hole, D-Insertion direction, L-Liquid, G-Insertion gap, O-Central shaft.

Claims

1. A pipe structure, characterized in that, have: Inner pipe; An outer conduit, comprising an end of the inner conduit inserted into the inner end, forming an annular insertion gap between the outer and inner conduits; and A pipe fitting, which is inserted into the inner side of the outer pipe and connects the inner pipe to the outer pipe. The pipe fitting has the following features: The first sleeve component has a groove for sealing liquid on its end face on the side opposite to the insertion direction of the inner pipe relative to the outer pipe. The second sleeve component has a protrusion on its end face on the insertion direction side that protrudes toward the first sleeve component; and A fastening mechanism that secures the second sleeve component to the first sleeve component by pressing the protrusion against the liquid within the groove. The groove is located radially inward from the fastening position in the first sleeve component, where the second sleeve component is fastened by the fastening mechanism.

2. The pipeline structure according to claim 1, characterized in that, The fastening mechanism has a bolt hole penetrating the second sleeve component, a bolt component inserted into the bolt hole along the insertion direction, and a threaded hole formed on the end face of the first sleeve component and engaged with the bolt component.

3. The pipeline structure according to claim 1, characterized in that, The groove and the protrusion extend in a ring shape, respectively.

4. The pipe structure according to claim 1, characterized in that, The outer pipe has a positioning part for positioning the first sleeve component.

5. A pipe fitting comprising an end of an inner pipe inserted into an inner end, and an end of an outer pipe forming an annular insertion gap with the inner pipe inserted into the inner end, connecting the inner pipe and the outer pipe, characterized in that it has: The first sleeve component has a groove for sealing liquid on its end face on the side opposite to the insertion direction of the inner pipe relative to the outer pipe. The second sleeve component has a protrusion on its end face in the insertion direction that protrudes toward the first sleeve component; and A fastening mechanism that secures the second sleeve component to the first sleeve component by pressing the protrusion against the liquid within the groove. The groove is located radially inward from the fastening position in the first sleeve component, where the second sleeve component is fastened by the fastening mechanism.

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