Pipe with joint

Abstract

To provide a pipe with a joint which can secure sealability.SOLUTION: A pipe 100 with a joint includes: a pipe 1; a joint 2; and a cylindrical seal member 3. An end of the pipe 1 includes: a first passage part 11A; a diameter expansion part 11X; and a second passage part 11B. The first passage part 11A and the second passage part 11B have diameters which are constant in an axial direction of the pipe 1. The diameter expansion part 11X is formed between the first passage part 11A and the second passage part 11B and has an outer diameter larger than those of the first passage part 11A and the second passage part 11B. The joint 2 has a cylindrical part 22. In a state that the seal member 3 is disposed between an outer peripheral surface of the end of the pipe 1 and an inner peripheral surface of the cylindrical part 22 so as to cover the first passage part 11A, the second passage part 11B, and the diameter expansion part 11X, the cylindrical part 22 is swaged from the outer side in a radial direction, excluding a portion where the cylindrical part 22 overlaps with the diameter expansion part 11X in the radial direction, at portions where the cylindrical part 22 overlaps with the first passage part 11A and the second passage part 11B in the radial direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a fitting-equipped pipe in which a pipe and a fitting are connected. [Background technology]

[0002] Patent Document 1 describes a pipe with a fitting in which a pipe and a fitting are connected. The pipe with a fitting described in Patent Document 1 includes a pipe, a fitting having a pipe insertion hole into which the end of the pipe is inserted, and a seal member disposed between the outer circumferential surface of the pipe and the inner circumferential surface of the fitting. A plurality of grooves are formed on the outer circumferential surface of the end of the pipe. The seal member is disposed between the outer circumferential surface of the pipe and the inner circumferential surface of the fitting so as to cover the plurality of grooves, and the fitting is crimped from the radially outward side, so that the seal member bites into the plurality of grooves in the pipe, ensuring sealing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-178212 Summary of the Invention [Problem to be solved by the invention]

[0004] Product standards for vehicle hoses and the like stipulate the inner diameter of the hose. Hoses with an inner diameter smaller than the stipulated inner diameter do not meet the product standards and cannot be manufactured. When using the pipe described in Patent Document 1 as a vehicle hose or the like, the inner diameter of the pipe must be equal to or greater than the stipulated inner diameter.

[0005] In the pipe described in Patent Document 1, multiple grooves are formed on the outer circumferential surface of the pipe by rolling or the like, but when the grooves are formed, the parts of the inner circumferential surface of the pipe that correspond to the grooves may protrude inward. One idea is to make the grooves on the outer circumferential surface of the pipe shallower so that the inner diameter of the protruding parts is equal to or greater than the inner diameter of the product standard, but if the grooves are shallower, there will be less sealing material that can fit into the grooves, making it difficult to improve sealing performance.

[0006] An object of the present invention is to provide a pipe with a fitting that can ensure sealing performance through a configuration different from conventional ones. [Means for solving the problem]

[0007] The fitting-equipped pipe disclosed in this specification comprises a metal pipe, a fitting having a tubular portion formed with a pipe insertion hole into which the end of the pipe is inserted, and a tubular sealing member made of resin or rubber and arranged between the outer surface of the end of the pipe and the inner surface of the tubular portion, wherein the end of the pipe has a plurality of flow path portions with a constant diameter in the axial direction of the pipe, and an expanded diameter portion formed between two flow path portions lined up in the axial direction of the pipe and having an outer diameter larger than that of the two flow path portions, and the sealing member is arranged between the outer surface of the end of the pipe and the inner surface of the tubular portion so as to cover the two flow path portions and the expanded diameter portion formed therebetween, and the tubular portion is crimped from the radially outer side of the tubular portion at portions that radially overlap with the two flow path portions, leaving a portion that radially overlaps with the expanded diameter portion.

[0008] In the above configuration, the length of each of the two flow path sections in the axial direction of the pipe may be longer than the length of the enlarged diameter section, the sealing members may be located outside the two flow path sections, and the sealing members may be located on both sides of the enlarged diameter section in the axial direction of the pipe.

[0009] In the above configuration, the expanded diameter portion may be convex outward in the radial direction.

[0010] In the above configuration, the end of the pipe may have a first portion having the multiple flow path portions and the expanded diameter portion, and a second portion having a larger diameter than the first portion, the second portion being farther from the tip of the end of the pipe than the first portion, a groove being formed on the outer surface of the second portion, the groove being located at the end of the pipe insertion side of the pipe insertion hole in the axial direction of the pipe, the groove being filled with adhesive, and the tubular portion being crimped from the radially outer side of the tubular portion at a portion that radially overlaps the groove. [Effects of the Invention]

[0011] A pipe with a fitting that can ensure sealing performance can be provided by using a configuration different from conventional ones. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a plan view of the fitting-equipped pipe according to the embodiment. [Figure 2] 2 is a cross-sectional view (cross-sectional view taken along line II-II in FIG. 1) of the fitting-equipped pipe according to the embodiment. [Figure 3] FIG. 3 is a cross-sectional view of the joint shown in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view of the pipe shown in FIG. 2. [Figure 5] 1A to 1C are cross-sectional views sequentially illustrating a method for manufacturing a jointed pipe (steps for manufacturing a pipe). [Figure 6] 1A to 1C are cross-sectional views sequentially illustrating a method for manufacturing a jointed pipe (attaching a sealing member to a pipe and filling with adhesive). [Figure 7] 1A to 1C are cross-sectional views sequentially illustrating a method for manufacturing a pipe with a fitting (a step of inserting a pipe into a fitting, and a step of crimping the fitting). [Figure 8] 4 is a cross-sectional view showing a method for manufacturing a jointed pipe (a step of crimping the joint). FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments will be described with reference to the drawings.

[0014] In the following, an embodiment will be described in which a fitting called an eye joint (glasses fitting) is used as the fitting of a fitting-equipped pipe. However, the fitting is not limited to an eye joint, and fittings of various shapes can be used as the fitting that constitutes a fitting-equipped pipe.

[0015] [Pipe with fittings] Figure 1 shows an external view of a fitting pipe 100. As shown in Figure 1, the fitting pipe 100 comprises a pipe 1, a fitting 2, and a cylindrical sealing member 3. The pipe 1 is used for hydraulic piping and the like.

[0016] (Joint) As shown in FIG. 1 , the joint 2 has an annular joint body 21 (glasses portion) and a tubular portion 22 (socket portion) protruding from the side surface of the joint body 21. A bolt or the like is inserted into a hole 21a surrounded by the peripheral wall of the joint body 21. A communication hole 21b having a smaller diameter than the hole 21a is formed in the peripheral wall of the joint body 21. The communication hole 21b penetrates the peripheral wall of the joint body 21 in the radial direction of the joint body 21 and is also formed in the tubular portion 22. The hole 21a and the communication hole 21b are perpendicular to each other and are in communication with each other.

[0017] The cylindrical portion 22 has a first cylindrical portion 31 on the joint body 21 side and a second cylindrical portion 32 on the opposite side to the joint body 21 side.

[0018] A communication hole 21b is formed in the axial direction of the first cylindrical portion 31. The communication hole 21b serves as a flow path for the fluid.

[0019] The second cylindrical portion 32 is a portion into which the end of the pipe 1 is inserted.

[0020] Figure 2 shows a cross-sectional view taken along line II-II in Figure 1. Figure 3 shows only a cross-sectional view of the joint 2 shown in Figure 2.

[0021] As shown in Fig. 3, a pipe insertion hole 32a is formed in the second cylindrical portion 32 of the cylindrical portion 22 of the joint 2. As shown in Fig. 2, the end of the pipe 1 is inserted into the pipe insertion hole 32a. As shown in Fig. 3, the pipe insertion hole 32a communicates with the communication hole 21b in the axial direction of the cylindrical portion 22. The diameter of the pipe insertion hole 32a is larger than the diameter of the communication hole 21b. The axial center of the pipe insertion hole 32a and the axial center of the communication hole 21b are the same.

[0022] When the end of the pipe 1 is inserted into the pipe insertion hole 32a, the communication hole 21b and the pipe 1 communicate with each other, as shown in FIG.

[0023] As shown in Figure 2, the second tubular portion 32 of the joint 2 is crimped from the radially outward direction, as described below. As shown in Figures 2 and 3, the crimped portion of the second tubular portion 32 is deformed, and the outer and inner peripheral surfaces of the crimped portion are recessed radially inward.

[0024] The joint 2 is made of metal. The material of the joint 2 is, for example, iron. The material of the joint 2 is not limited to iron, and may be a metal material other than iron, such as stainless steel, brass, or copper. The joint 2 may be plated or resin coated.

[0025] (pipe) Figure 4 shows only a cross-sectional view of the end of the pipe 1 shown in Figure 2. Figure 4 is a cross-sectional view passing through the axis of the pipe 1. The end of the pipe 1 shown in Figure 4 is the portion that is inserted into the pipe insertion hole 32a of the fitting 2 shown in Figure 3.

[0026] As shown in FIG. 4 , the end of the pipe 1 has, in order from the tip, a first portion 11, a step portion 12 whose diameter increases with increasing distance from the first portion 11, and a second portion 13. The outer diameter of the first portion 11 is smaller than the outer diameter of the second portion 13. The inner diameter of the first portion 11 is smaller than the inner diameter of the second portion 13. In this embodiment, when the outer diameter of the first portion 11 is smaller than the outer diameter of the second portion 13 and the inner diameter of the first portion 11 is smaller than the inner diameter of the second portion 13, this is referred to as "the diameter of the first portion 11 is smaller than the diameter of the second portion 13." The step portion 12 has a tapered shape that tapers from the second portion 13 side toward the first portion 11 side.

[0027] The first section 11 of the pipe 1 has two flow path sections (first flow path section 11A, second flow path section 11B) with a constant diameter in the axial direction of the pipe 1, and an expanded diameter section 11X formed between the two flow path sections. The first flow path section 11A, the expanded diameter section 11X, and the second flow path section 11B are arranged in this order from the tip side of the end of the pipe 1.

[0028] The inner and outer diameters of the first flow path section 11A are constant in the axial direction of the pipe 1. The inner and outer diameters of the second flow path section 11B are constant in the axial direction of the pipe 1. In this embodiment, the fact that the inner and outer diameters (of the pipe 1) are constant in the axial direction of the pipe 1 is referred to as "the diameter (of the pipe 1) being constant in the axial direction of the pipe 1." In FIG. 4 and other drawings, the inner and outer diameters of the first flow path section 11A are the same as the inner and outer diameters of the second flow path section 11B, respectively. However, the inner and outer diameters of the first flow path section 11A may be different from the inner and outer diameters of the second flow path section 11B, respectively. Furthermore, in FIG. 4 and other drawings, the length of the first flow path section 11A and the length of the second flow path section 11B are the same in the axial direction of the pipe 1. However, the length of the first flow path section 11A and the length of the second flow path section 11B may be different in the axial direction of the pipe 1.

[0029] The outer diameter of the expanded diameter portion 11X of the pipe 1 is larger than the outer diameter of the first flow path portion 11A and the outer diameter of the second flow path portion 11B. The inner diameter of the expanded diameter portion 11X of the pipe 1 is larger than the inner diameter of the first flow path portion 11A and the inner diameter of the second flow path portion 11B. As shown in FIG. 4, in a cross-sectional view passing through the axis of the pipe 1, the expanded diameter portion 11X is convex outward in the radial direction and curved in an arc. In the axial direction of the pipe 1, the length of the expanded diameter portion 11X is shorter than the length of the first flow path portion 11A and shorter than the length of the second flow path portion 11B. The outer diameter of the expanded diameter portion 11X is smaller than the outer diameter of the second portion 13.

[0030] A groove 13a is formed on the outer peripheral surface of the second portion 13 of the pipe 1. The groove 13a is a ring-shaped groove. The groove 13a is filled with adhesive 10. As shown in FIG. 2, when the end of the pipe 1 is inserted into the pipe insertion hole 32a of the fitting 2, the groove 13a is located at the end of the pipe insertion hole 32a on the side where the pipe 1 is inserted. The "end of the pipe insertion hole 32a on the side where the pipe 1 is inserted" is the end of the pipe insertion hole 32a on the opposite side from the communication hole 21b, and is the end of the pipe insertion hole 32a on the side where the pipe 1 is inserted, as shown in FIG. 7 described later.

[0031] There is no limitation on the number of grooves 13a formed in the second portion 13 of the pipe 1 shown in Fig. 4. One groove 13a may be formed in the second portion 13, or multiple grooves 13a may be formed.

[0032] The outer diameter of the second portion 13, excluding the groove 13a, is constant in the axial direction of the pipe 1. As shown in Figure 2, when the end of the pipe 1 is inserted into the pipe insertion hole 32a of the fitting 2, the outer peripheral surface of the second portion 13 contacts the inner peripheral surface of the second tubular portion 32 of the fitting 2.

[0033] The pipe 1 is made of metal. The material of the pipe 1 is, for example, iron. The material of the pipe 1 is not limited to iron, and may be a metal material other than iron, such as stainless steel, brass, or copper. The pipe 1 may be plated or resin coated.

[0034] (Sealing material) 2, the sealing member 3 is disposed between the outer peripheral surface of the end of the pipe 1 and the inner peripheral surface of the second cylindrical portion 32 of the fitting 2. The sealing member 3 seals between the pipe 1 and the fitting 2. This prevents fluid from leaking from between the pipe 1 and the fitting 2.

[0035] The sealing member 3 covers the first flow path portion 11A, the expanded diameter portion 11X, and the second flow path portion 11B of the first portion 11. The sealing member 3 also covers a portion of the step portion 12. The sealing member 3 does not cover the second portion 13. In FIG. 2, the sealing member 3 covers a portion of the step portion 12, but the sealing member 3 does not have to cover the step portion 12, and may cover the entire step portion 12.

[0036] When the second tubular portion 32 of the joint 2 is crimped, the portion of the sealing member 3 that radially overlaps the crimped portion is deformed and comes into close contact with the inner circumferential surface of the pipe 1. The upper diagram of Figure 6, which will be described later, shows the sealing member 3 before deformation.

[0037] The sealing member 3 is made of resin or rubber, for example, fluororesin.

[0038] (crimping) 2, with the sealing member 3 disposed between the outer peripheral surface of the end of the pipe 1 and the inner peripheral surface of the second cylindrical portion 32 of the fitting 2, the second cylindrical portion 32 of the fitting 2 is crimped from the radially outer side of the second cylindrical portion 32. In this state, the first flow path portion 11A, the expanded diameter portion 11X, and the second flow path portion 11B of the first section 11 of the pipe 1 are covered by the sealing member 3.

[0039] In the above state, the second cylindrical portion 32 of the fitting 2 is crimped from the radially outward direction at portions that radially overlap with the first flow path portion 11A and the second flow path portion 11B of the pipe 1, leaving a portion that radially overlaps with the expanded diameter portion 11X. As a result, the second cylindrical portion 32 of the fitting 2 and the sealing member 3 are deformed radially inward at portions that radially overlap with the first flow path portion 11A and the second flow path portion 11B of the pipe 1.

[0040] In the above state, the portion of the end of the second cylindrical portion 32 of the joint 2 (the end of the pipe insertion hole 32a on the pipe insertion side) that radially overlaps with the groove 13a of the pipe 1 is crimped from the radially outward direction. As a result, the portion of the second cylindrical portion 32 of the joint 2 that radially overlaps with the groove 13a is deformed radially inward.

[0041] Next, an example of a method for manufacturing the jointed pipe 100 will be described.

[0042] The upper diagram in Figure 5 shows a pipe (blank pipe) 201 before it becomes pipe 1. First, the tip portion of pipe (blank pipe) 201 is subjected to diameter reduction processing. This results in a pipe 202 having a reduced diameter portion 211, a tapered step portion 12, and a second portion 13 at its end. The reduced diameter portion 211 is a portion before it becomes first portion 11. The inner and outer diameters of the reduced diameter portion 211 are smaller than those of the second portion 13. The second portion 13 is the second portion 13 before the groove 13a shown in Figure 4 is formed. The second portion 13 has the same diameter as, or approximately the same diameter as, the pipe (blank pipe) 201 shown in the upper diagram in Figure 5.

[0043] Next, an expanded diameter section 11X having an outer diameter larger than that of the reduced diameter section 211 is formed in the axial middle of the reduced diameter section 211. There is no particular limitation on the method for forming the expanded diameter section 11X. As a result, as shown in the bottom diagram of Figure 5, a first section 11 having a first flow path section 11A, an expanded diameter section 11X, and a second flow path section 11B in this order from the tip of the end of the pipe 1 is formed.

[0044] Here, the inner diameter and outer diameter of the first flow path section 11A are the same as or approximately the same as the inner diameter and outer diameter of the reduced diameter section 211 before the formation of the expanded diameter section 11X. The inner diameter and outer diameter of the second flow path section 11B are the same as or approximately the same as the inner diameter and outer diameter of the reduced diameter section 211 before the formation of the expanded diameter section 11X. The inner diameter and outer diameter of the expanded diameter section 11X are larger than the inner diameter and outer diameter of the reduced diameter section 211 before the formation of the expanded diameter section 11X.

[0045] In addition, a ring-shaped groove 13a is formed in the second portion 13.

[0046] As a result of the above, a pipe 1 is obtained which has, at its end, in order from the tip side, the first portion 11, the step portion 12, and the second portion 13 in which the groove 13a is formed.

[0047] Next, a cylindrical member (not shown) made of resin or rubber is cut to prepare the sealing member 3 shown in Fig. 6. The first portion 11 of the pipe 1 is inserted into the sealing member 3, thereby attaching the sealing member 3 to the outer peripheral surface of the first portion 11.

[0048] The groove 13a of the second portion 13 is filled with adhesive 10. In the lower drawing of Fig. 6, the adhesive 10 is filled over the entire circumference of the groove 13a, but the adhesive 10 may be filled only in a portion of the groove 13a.

[0049] The order in which the sealing member 3 is attached to the pipe 1 and the adhesive 10 is filled may be any.

[0050] Next, as shown in FIG. 7, the end of the pipe 1 with the seal member 3 attached is inserted into the pipe insertion hole 32a of the fitting 2. As shown in the lower diagram of FIG. 7, one end of the seal member 3 is brought to the innermost part of the pipe insertion hole 32a. This places the seal member 3 between the outer circumferential surface of the first section 11 of the pipe 1 and the inner circumferential surface of the second cylindrical section 32 of the fitting 2. In the state shown in the lower diagram of FIG. 7, the first flow path section 11A, the expanded diameter section 11X, and the second flow path section 11B of the first section 11 of the pipe 1 are covered by the seal member 3. In addition, the groove 13a of the pipe 1 is located at the end of the pipe insertion hole 32a on the pipe insertion side in the axial direction of the pipe 1.

[0051] In the state shown in the lower diagram of Figure 7, the second tubular portion 32 of the fitting 2 is crimped from the radial outside of the second tubular portion 32. The crimping positions are the portion of the second tubular portion 32 that radially overlaps with the first flow path portion 11A of the pipe 1 and the portion that radially overlaps with the second flow path portion 11B. Along with these portions, the portion that radially overlaps with the expanded diameter portion 11X is not crimped. The portion that radially overlaps with the first flow path portion 11A and the portion that radially overlaps with the second flow path portion 11B are crimped, leaving the portion that radially overlaps with the expanded diameter portion 11X between them open. This fixes the second tubular portion 32 to the pipe 1.

[0052] 8, at the end of the second cylindrical portion 32 on the pipe insertion side, a portion that radially overlaps with the groove 13a of the pipe 1 is crimped from the radial outside of the second cylindrical portion 32. This fixes the end of the second cylindrical portion 32 on the pipe insertion side to the pipe 1. Fixing the end of the second cylindrical portion 32 on the pipe insertion side to the pipe 1 is called skirt crimping. Note that crimping of the portion that radially overlaps with the groove 13a of the pipe 1 shown in FIG. 8 may be performed after or simultaneously with crimping of the portion that radially overlaps with the first flow path portion 11A of the pipe 1 and the portion that radially overlaps with the second flow path portion 11B of the pipe 1 shown in the lower diagram of FIG. 7.

[0053] The crimping may be performed by eight-way crimping, which crimps the crimped portion from eight sides, or hexagonal crimping, which crimps from six sides. Note that the crimping is not limited to eight-way crimping or hexagonal crimping, and it is sufficient that the second cylindrical portion 32 of the joint 2 is crimped from multiple directions radially outward from the second cylindrical portion 32.

[0054] Thereafter, a heat treatment is carried out to harden the adhesive 10. In this way, a pipe with a coupling 100 is obtained.

[0055] 6 and 7, the sealing member 3 is attached to the pipe 1, and then the end of the pipe 1 with the sealing member 3 attached is inserted into the pipe insertion hole 32a of the joint 2. However, after the sealing member 3 is inserted into the pipe insertion hole 32a of the joint 2, the end of the pipe 1 with the adhesive 10 filled in the groove 13a of the pipe 1 may be inserted into the pipe insertion hole 32a (the sealing member 3 inserted into the pipe insertion hole 32a).

[0056] The joint-equipped pipe 100 of this embodiment provides the following effects.

[0057] 2, a first flow path section 11A, an expanded diameter section 11X, and a second flow path section 11B are formed in this order from the tip of the pipe 1 in the first section 11 of the pipe 1, on which the seal member 3 is arranged on the outside. The outer diameter of the expanded diameter section 11X is larger than the outer diameter of the first flow path section 11A and the outer diameter of the second flow path section 11B.

[0058] 2, a seal member 3 is disposed between the inner peripheral surface of the second cylindrical portion 32 of the fitting 2 and the outer peripheral surface of the first section 11 of the pipe 1, and with the first flow path section 11A, the expanded diameter section 11X, and the second flow path section 11B of the first section 11 of the pipe 1 covered with the seal member 3, the portions radially overlapping with the first flow path section 11A and the second flow path section 11B are crimped from the radially outer side of the second cylindrical portion 32, leaving a portion radially overlapping with the expanded diameter section 11X between them. As a result, the second cylindrical portion 32 and the seal member 3 of the fitting 2 are deformed at the crimped portions, and the inner peripheral surface of the second cylindrical portion 32 and the seal member 3 are in close contact with each other at the crimped portions, and the seal member 3 is also in close contact with the outer peripheral surface of the pipe 1. Therefore, sealing is ensured at the portion of the first section 11 of the pipe 1 that overlaps with the first flow path portion 11A in the radial direction and at the portion that overlaps with the second flow path portion 11B in the radial direction.

[0059] Note that the second tubular portion 32 of the joint 2 and the seal member 3 are not deformed by crimping at the portion that overlaps the enlarged diameter portion 11X in the radial direction. However, because the outer diameter of the enlarged diameter portion 11X is large, the seal member 3 covering the enlarged diameter portion 11X deforms and becomes convex radially outward. This brings the enlarged diameter portion 11X and the seal member 3 that covers it into close contact. Furthermore, the convex seal member 3 covering the enlarged diameter portion 11X comes into contact with the second tubular portion 32 of the joint 2, bringing the seal member 3 covering the enlarged diameter portion 11X and the second tubular portion 32 of the joint 2 into close contact. Therefore, sealing is ensured even at the portion that overlaps the enlarged diameter portion 11X in the radial direction.

[0060] As a result, a high seal is achieved between the entire first portion 11 of the pipe 1 and the second tubular portion 32 of the fitting 2. This ensures a high seal with the fitting-equipped pipe 100 having a configuration different from conventional ones.

[0061] If the portion of the second cylindrical portion 32 of the joint 2 that overlaps radially with the expanded diameter portion 11X and the portions that overlap radially with the first flow path portion 11A and the second flow path portion 11B on both sides of the expanded diameter portion 11X are crimped overall (parallel), it is presumed that the large outer diameter of the expanded diameter portion 11X will cause the crimping force of the portions that radially overlap with the first flow path portion 11A and the second flow path portion 11B on both sides to be smaller than the crimping force of the portions that radially overlap with the expanded diameter portion 11X. Therefore, it is presumed that sealing performance cannot be ensured in the portions that radially overlap with the first flow path portion 11A and the second flow path portion 11B. By leaving the portion that radially overlaps with the enlarged diameter portion 11X empty and crimping the portions that radially overlap with the first flow path portion 11A and the second flow path portion 11B on both sides of it, it is believed that sealing can be ensured in both the portion that radially overlaps with the enlarged diameter portion 11X and the portions that radially overlap with the first flow path portion 11A and the second flow path portion 11B on both sides of it.

[0062] Furthermore, while product standards for vehicle hoses stipulate a minimum hose inner diameter, the enlarged diameter portion 11X has an enlarged inner and outer diameter, so the hose inner diameter in the product standards does not need to be taken into consideration. Furthermore, since there is no need to consider product standards when increasing the inner and outer diameters of the pipe, the inner and outer diameters of the enlarged diameter portion 11X can be enlarged.

[0063] 2, in the axial direction of the pipe 1, there are seal members 3 crimped from the radially outward on both sides of the enlarged diameter portion 11X. The seal members 3 on both sides of the enlarged diameter portion 11X are deformed radially inward by the crimping described above. As a result, even if the pipe 1 is pulled, it is difficult for the pipe 1 to come out of the pipe insertion hole 32a of the fitting 2. Therefore, the tensile strength of the fitting-equipped pipe 100 can be ensured.

[0064] 2, the length of the first flow path portion 11A and the length of the second flow path portion 11B are longer than the length of the enlarged diameter portion 11X in the axial direction of the pipe 1. This increases the amount of sealing member 3 present on both sides of the enlarged diameter portion 11X, making it more difficult for the pipe 1 to come out of the pipe insertion hole 32a of the fitting 2 even if the pipe 1 is pulled. This ensures the tensile strength of the fitting-equipped pipe 100.

[0065] 2, the expanded diameter portion 11X of the pipe 1 has a simple shape that is convex outward in the radial direction. By forming the expanded diameter portion 11X of this shape in the middle of the pipe 1, it is possible to ensure sealing between the pipe 1 and the fitting 2. It is also possible to ensure the tensile strength of the fitting-equipped pipe 100.

[0066] 2, with the groove 13a of the pipe 1 filled with adhesive 10, the second tubular portion 32 of the fitting 2 is crimped at the portion that radially overlaps with the groove 13a. As a result, the second tubular portion 32 of the fitting 2 deforms radially inward at the portion that radially overlaps with the groove 13a, and is in close contact with the adhesive 10. This makes it more difficult for the pipe 1 to come out of the pipe insertion hole 32a of the fitting 2, even if the pipe 1 is pulled. This increases the tensile strength of the fitting-equipped pipe 100.

[0067] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configurations should not be considered to be limited to these embodiments. The scope of the present invention is defined not by the above description but by the claims, and includes all modifications within the meaning and scope of the claims.

[0068] 2 and 4, in the above embodiment, the length of the first flow path section 11A and the length of the second flow path section 11B are longer than the length of the enlarged diameter section 11X in the axial direction of the pipe 1. However, the length of the first flow path section 11A and the length of the second flow path section 11B in the axial direction of the pipe 1 may be the same as or shorter than the length of the enlarged diameter section 11X.

[0069] As shown in FIG. 4, the first portion 11 at the end of the pipe 1 has two flow path sections (first flow path section 11A, second flow path section 11B) and one enlarged diameter section 11X. However, the first portion 11 at the end of the pipe 1 may have three or more flow path sections and two or more enlarged diameter sections. In this case, the flow path sections and enlarged diameter sections are alternately arranged in the axial direction of the pipe 1. At least one enlarged diameter section is present between two flow path sections arranged in the axial direction of the pipe 1. In other words, there are flow path sections on both sides of at least one enlarged diameter section. Furthermore, in the second tubular section of the joint, the portions that radially overlap with the flow path sections on both sides of the enlarged diameter section are crimped from the radially outward direction, leaving a portion that radially overlaps with the enlarged diameter section between the two flow path sections.

[0070] 4, in a cross section passing through the axis of the pipe 1, the expanded diameter portion 11X is convex radially outward and curved in an arc. However, the shape of the expanded diameter portion 11X is not limited to the shape shown in FIG. 4. For example, in a cross section passing through the axis of the pipe 1, the expanded diameter portion 11X may be triangular or rectangular.

[0071] 4, the inner diameter and outer diameter of the expanded diameter section 11X are larger than the inner diameter and outer diameter of the first flow path section 11A, respectively. The inner diameter and outer diameter of the expanded diameter section 11X are larger than the inner diameter and outer diameter of the second flow path section 11B, respectively. However, the outer diameter of the expanded diameter section 11X needs to be larger than the outer diameter of the first flow path section 11A and the outer diameter of the second flow path section 11B, and the inner diameter of the expanded diameter section 11X may be the same as or equivalent to the inner diameter of the first flow path section 11A and the inner diameter of the second flow path section 11B.

[0072] 2, a tapered step portion 12 is formed at the end of the pipe 1 between the first portion 11 and the second portion 13. However, the tapered step portion 12 does not have to be formed between the first portion 11 and the second portion 13.

[0073] 2, a groove 13a is formed in the second portion 13 of the pipe 1, and the groove 13a is filled with adhesive 10. However, the groove 13a does not have to be filled with adhesive 10. The end of the second tubular portion 32 of the fitting 2 is crimped from the radially outward direction, and the inner circumferential surface of the second tubular portion 32 is pressed against the groove 13a, which also makes it difficult for the pipe 1 to come loose. The second portion 13 of the pipe 1 does not have to have the groove 13a formed therein. [Explanation of symbols]

[0074] 1 pipe 2. Joints 3 Sealing material 10. Adhesive 11 Part 1 11A first flow path section (flow path section) 11B second flow path section (flow path section) 11X enlarged diameter section 12 Step 13a Groove 13 Part 2 21 Joint body 21a hole 21b Communication hole 22 Cylindrical part 31 First cylindrical portion 32 Second cylindrical section 32a Pipe insertion hole 100 Pipe with fittings 211 Reduced diameter part

Claims

1. Metal pipes and a fitting having a cylindrical portion formed with a pipe insertion hole into which the end of the pipe is inserted; a cylindrical seal member made of resin or rubber and disposed between an outer peripheral surface of the end of the pipe and an inner peripheral surface of the cylindrical portion; Equipped with the end of the pipe has a plurality of flow path portions having a constant diameter in the axial direction of the pipe, and an expanded diameter portion formed between two flow path portions aligned in the axial direction of the pipe and having an outer diameter larger than the two flow path portions, the sealing member is disposed between the outer peripheral surface of the end of the pipe and the inner peripheral surface of the cylindrical portion so as to cover the two flow path portions and the enlarged diameter portion formed therebetween, and the cylindrical portion is crimped from the radially outer side of the cylindrical portion at a portion where the cylindrical portion radially overlaps with the two flow path portions and at a portion where the cylindrical portion radially overlaps with the enlarged diameter portion, Pipe with fittings.

2. In the axial direction of the pipe, the length of each of the two flow path portions is longer than the length of the enlarged diameter portion, the sealing member is present outside the two flow path portions, The sealing members are present on both sides of the expanded diameter portion in the axial direction of the pipe. The fitting pipe according to claim 1.

3. The enlarged diameter portion is convex radially outward. The fitting pipe according to claim 1 or 2.

4. the end of the pipe has a first portion having the plurality of flow passage portions and the enlarged diameter portion, and a second portion having a larger diameter than the first portion, the second portion is farther from the tip of the end of the pipe than the first portion; a groove is formed on the outer circumferential surface of the second portion; the groove is located at an end of the pipe insertion hole on the pipe insertion side in the axial direction of the pipe, The groove is filled with adhesive, The cylindrical portion is crimped from the radially outer side of the cylindrical portion at a portion that overlaps with the groove in the radial direction. The fitting pipe according to claim 1 or 2.

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