TWI546483B - Joint and connector assembly - Google Patents

Description

Joint and joint assembly

The present invention relates to a joint and joint assembly.

As described in Japanese Laid-Open Patent Publication No. 2009-144916, a pipe joint has been proposed which is firmly connected so that the fluid passing through the inside of the pipe does not leak. . Here, as the outer diameter of the tube to which the pipe joint is attached, various dimensions of 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, and 1 inch are proposed.

In the pipe joint, when a pipe is attached to an end portion of the tubular joint body to screw the joint nut with respect to the joint body, a fixing ring is provided between the joint body and the joint nut. Further, when the coupling nut is screwed to the joint body, the pipe is fastened by a joint ring that is pressed from the outer side by a joint nut from the outer side.

In the pipe joint, when the coupling nut is screwed to the joint body by the above configuration, the coupling nut rotates relative to the pipe, but the fixing ring does not rotate with respect to the pipe, thereby preventing the pipe from being rotated. A ring-shaped flaw is attached to the outer surface or the tube is cut.

Moreover, the hardness of the fixing ring is made harder than the hardness of the tube, whereby the connection can be made firm so that the tube does not fall off the pipe joint, and the joint nut can be prevented when the joint nut is fixed to the joint body. Deformation occurs (refer to paragraph number 0021 of Ref. 1, etc.).

[Advanced technical literature] [Patent Literature]

[Patent Document 1]

Japanese Patent Laid-Open Publication No. 2009-144916

In the joint described in the above-mentioned Patent Document 1 (Japanese Laid-Open Patent Publication No. 2009-144916), the outer diameter of the tube is proposed to be at most 1 inch.

The inventors have attempted to develop a pipe having a larger size which can secure a larger flow rate of a fluid flowing in a pipe, and a pipe joint connected to the pipe.

Moreover, the pipe joints used on the larger-sized pipes are easier to fall off than the pipe joints having a smaller size, and are liable to cause fluid leakage.

On the other hand, by making the hardness of the fixing ring harder than the hardness of the tube, it is difficult for the tube to fall off from the pipe joint. However, when the elastic modulus of the fixing ring is too high, the deflection generated on the fixing ring is very small when the connecting nut is screwed to the joint body, and the tube is excessively fastened from the radially outer side toward the inner side. Thus, there is a flaw in the tube being cut.

Thus, the elastic modulus of the retaining ring has a desirable range for suppressing the falling off of the tube on the one hand and the difficulty of attaching the flaw on the outer surface of the tube. Further, the fixing ring is designed in such a manner as to be an elastic modulus of the desired range, whereby the outer surface of the tube can be directed toward the outer side of the tube from the outer surface of the tube in a state in which the tube and the pipe joint are firmly connected. The elastic force of the fixing ring acts on the inner side, and the tube can be gripped with an appropriate force by the fixing ring and the joint body, so that the connection can be made firm so that the tube is not cut.

However, as described above, in a state in which the pipe is connected to the pipe joint in such a manner that a strong connection can be suppressed to suppress the cutting of the pipe, some external force acts on the pipe by stretching or bending the pipe. situation. As described above, in the above-described connected state, if an external force acts on the tube, the fixing ring expands outward in the radial direction beyond the elastic region of itself. As described above, when an external force acts on the tube and the fixing ring is in a state beyond the elastic region of the self, it is difficult to apply a force to the radially inner side of the self-retaining ring to the inner side in the radial direction, so that the tube is easily detached from the pipe joint.

The present invention has been made in view of the above points, and an object of the present invention is to provide a The joint and the joint assembly can suppress the dropping of the pipe or the leakage of the fluid even in the case of a large size.

The joint of the first aspect is a joint that is connected to a tube having at least an inner surface made of a resin, and includes a body, a nut, and at least one ring. The main body has a pipe joint portion provided at one end, and a body thread portion provided on the outer peripheral surface such that the outer diameter is larger than the pipe joint portion. A through hole extending in the axial direction is formed on the body. The nut has a nut thread portion, a reduced diameter portion, and a contacted portion. The nut thread portion is screwed to the main body thread portion of the main body in a state where the tube coupling portion of the main body is inserted into the other end side in the axial direction from the one end side in the axial direction with respect to the nut. The reduced diameter portion is provided on the other end side of the nut in the axial direction, and the inner diameter is smaller than the nut thread portion. The abutted portion is formed to face one end side in the axial direction with respect to the reduced diameter portion. At least one ring system is disposed in a space radially inward of the threaded portion of the nut of the nut, and has a higher modulus of elasticity than the tube and abuts against the abutted portion of the nut. The ring has an elastic modulus that satisfies the following conditions. That is, in the state where the body, the nut, and the ring are connected to the tube, when the ring is in the state of the elastic region, the ring can press the tube from the radially outer side toward the radially inner side by the stress of the ring itself. Further, in a state in which the body, the nut, and the ring are coupled to the tube, when the ring is in a state beyond the elastic region, the expanded ring is radially inward by the radially inner side surface of the nut. Squeeze, and the tube can be squeezed from the radially outer side toward the radially inner side.

In the state in which the tube is attached to the body such that the inner surface of the tube is in contact with the outer surface of the tube connecting portion of the body, if the threaded portion of the nut of the nut is screwed to the threaded portion of the body of the body When screwed in, the ring on the outer side of the tube abuts against the abutted portion of the nut and approaches the end of the pipe joint of the body. Further, in a state in which one of the tubes is sandwiched by the end portion of the tube connecting portion between the ring and the body, the ring is elastically deformed so as to expand outward in the radial direction. In the elastic state in which the ring is elastically deformed, the elastic force acts on the tube in such a manner that the tube is pressed radially inward from the radially outer side.

Here, even in the case where the joint is connected to a tube composed of a resin, since the elastic modulus is higher than the elastic modulus of the tube, it can be pressed by the strong elastic force of the ring. By the pipe, the pipe is firmly fixed, so that the pipe is hard to fall off, and leakage of the fluid passing through the inside of the pipe can be suppressed.

Moreover, in a state in which the nut is screwed to the body and the joint is fixed to the tube, even if some external force acts on the tube, the tube can be prevented from falling off by the elastic modulus of the ring. . Further, in a state in which the joint is fixed to the tube and some external force acts on the tube, the ring can be deformed to be further expanded and beyond the elastic region. Thereby, the tube can be prevented from being excessively fastened, and the tube can be prevented from being cut.

Further, even in the case where the ring expands and deforms to be in a state beyond the elastic region, the radially outer portion of the expanded ring abuts against the radially inner side surface of the nut, and by the inner circumference of the nut Partially pressed toward the inside in the radial direction. In this way, the ring which is pressed radially inward by the nut presses and fastens the tube from the radially outer side toward the radially inner side, so that the tube is hard to fall off, and the leakage of the fluid passing through the inside of the tube can be suppressed. .

According to the above, with the joint, even when the size of the tube is large, the tube can be prevented from being cut, and the falling of the tube or the leakage of the fluid can be suppressed.

The joint of the second aspect is the joint of the first aspect, wherein in the state in which the body, the nut and the ring are connected to the pipe, in the state in which the ring is in the elastic region, the ring and the outer peripheral portion, and the ring in the ring A radial gap is provided between the inner peripheral portions of the outer nut.

In the joint, in the state where the ring is elastically deformed, the tube is fixed by the elastic force of the ring, and the outer peripheral portion of the ring is not in contact with the portion of the inner peripheral portion of the nut located radially outward of the ring. . Therefore, when the tube is fixed by the elastic force of the ring in a state where the ring is elastically deformed, it is possible to suppress the nut from being deformed so as to expand the pipe radially outward.

The joint of the third aspect is the joint of the first aspect or the second aspect, wherein the elastic modulus of the ring Higher than the elastic modulus of the nut.

In the joint, the elastic modulus of the ring is not only higher than the elastic modulus of the pipe, but also higher than the elastic modulus of the nut. Therefore, even if the ring is deformed to a degree beyond the elastic region, and the outer peripheral portion of the ring abuts against the inner peripheral portion of the nut and is pressed radially inward, the elastic modulus of the nut is high or low. Rather than the degree of the elastic modulus of the ring, it is also possible to suppress excessive tightening of the tube, thereby suppressing the tube from being cut.

A joint according to any one of the first aspect to the third aspect, wherein the shape of the cross section of the ring in the normal direction in the circumferential direction is a rectangular shape, at least the inner side in the radial direction, and the main body side in the axial direction The part is chamfered or has a rounded shape. a chamfered shape of a portion of the inner side of the ring and the body side of the axial direction or a portion having a radius of a part of the radius of the radius of 0.3% or more and 40% or less, and a loop The portion of the width in the axial direction is 1% or more and 40% or less.

In the joint, when the nut is screwed into the body, the tube is held by the end portion of the tube connecting portion of the body and the ring. However, at this time, the ring is radially inward of the ring and in the axial direction. On the part of the body side, it is in contact with the tube. Further, in the joint, the radially inner side of the ring and the portion on the main body side in the axial direction (the portion of the radial direction of the ring is 0.3% or more and 40% or less, and the width of the ring in the axial direction is 1% or more and 40% or less) are chamfered or rounded. Therefore, even in the case where a joint having a ring having a higher elastic modulus is connected to the tube and fixed, it is provided with a corner which does not adopt a chamfered shape or a shape with rounded corners. In comparison, it is also difficult to apply a partial pressure to the tube from the ring. Thereby, it is possible to suppress the tube from being cut. Further, the radially inner side of the ring and the portion on the main body side in the axial direction (the portion which is 0.3% or more and 40% or less of the width of the radial direction of the ring) may be 1% or more of the width of the ring axis direction. The contact area of the portion other than 40% or less on the outer side of the tube is not too large, so that the force which is pressed against the tube by the ring can be suppressed from being dispersed, and the tube can be easily detached.

The joint of the fifth aspect is the joint of the fourth aspect, wherein the radially inner side of the ring and the axial side a portion of the chamfered portion of the body side or a portion of the radius of the radius of the portion having a radius of 3% or more and 29% or less, and 2% of the width of the axial direction of the loop Above and below 25%.

On the one hand, the joint can further reduce the possibility of the tube being severed, on the one hand making the ring trapped relative to the tube to ensure tensile strength.

The joint of any one of the first to fifth aspects, wherein the body, the nut and the ring are connected to the tube, and in the state where the ring is in the elastic region, the nut is In the inner peripheral portion, when the inner diameter of the portion located radially outward with respect to the outermost portion of the ring is X, and the outer diameter of the portion where the outer diameter of the ring is the largest is set to Y, Regarding the length of the portion corresponding to X and Y in a state in which the nut and the ring are not connected without any force, the value of (XY)/Y is 0.003 or more and 0.020 or less.

The joint can be more reliably brought into a state outside the elastic state at the stage of connection with the tube, expansion of the ring, and before the contact with the inner peripheral portion of the nut. Thereby, it is possible to more reliably suppress the ring from being in contact with the inner peripheral portion of the nut while maintaining the elastic state, and the tube is excessively pressed against and cut.

The joint of any one of the first to sixth aspects, wherein the body, the nut and the ring are connected to the tube, and in the state where the ring is located in the elastic region, the nut is In the inner peripheral portion, the inner diameter of the portion located radially outward with respect to the outermost portion of the ring is set to X, and the outer diameter of the portion where the outer diameter of the ring is the largest is set to Y, and the tube is When the thickness is set to Z, the value of (XY)/Z is the length of the portion corresponding to X, Y, and Z in a state where the nut, the ring, and the tube are not connected to each other without any force. 0.04 or more and 0.30 or less.

When the joint is connected to the tube, the ring is expanded, and the tube is flattened, and the tube is excessively crushed and cut before the tube is cut, the state of the ring can be more reliably made to exceed the elastic region. Thereby, the tube can be more reliably suppressed from being cut.

A joint of any one of the first to seventh aspects, wherein the tube comprises Containing a composition selected from the group consisting of PFA (Polyfluoroalkoxy, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), FEP (Fluoroethylene Propylene, tetrafluoroethylene-hexafluoropropylene copolymer) and PTFE (Polytetrafluoroethylene) A resin composition of at least one of the group. The nut comprises a material selected from the group consisting of PFA, PCTFE (Polychlorotrifluoroethylene), PVDF (Poly(vinylidene difluoride), Poly(vinylidene difluoride), ETFE (Ethylene-tetra-fluoro-ethylene, A resin composition of at least one of a group consisting of ethylene-tetrafluoroethylene copolymer and PPS (Polyphenylene sulfide). The ring contains a resin composition containing at least one selected from the group consisting of PCTFE, PVDF, ETFE, and PPS.

The joint can more reliably suppress the tube from being cut, and can more reliably suppress the falling of the tube or the leakage of the fluid.

A joint of any one of the first to eighth aspects, wherein the ring is opaque. The nut is transparent or translucent.

In the joint, the nut is transparent or translucent, and the ring is opaque. Therefore, in the state in which the ring and the nut are coupled to the tube, the presence of the ring can be confirmed from the outer side of the nut. Thereby, it can be difficult to generate a situation in which the loop is forgotten to be installed.

The joint assembly system of the tenth aspect includes a tube and a joint according to any one of the first to ninth aspects. The tube is composed of a resin having chemical resistance. The bending radius of the tube is 0.3 m or more and 3.0 m or less.

This joint assembly differs from a tube containing iron in that, since the tube is easily bent, even if it is necessary to transport a long tube to the site in order to connect for a long distance, the tube may be wound or the like to be small. Carry it out.

In the joint of the first aspect, even when the size of the tube is large, the tube can be prevented from being cut, and the falling of the tube or the leakage of the fluid can be suppressed.

In the joint of the second aspect, when the tube is fixed by the elastic force of the ring in a state where the ring is elastically deformed, the nut can be prevented from being deformed so as to expand the pipe radially outward.

In the case of the joint of the third aspect, even if the ring is deformed to a degree beyond the elastic region, and the outer peripheral portion of the ring abuts against the inner peripheral portion of the nut and is pressed toward the inner side in the radial direction, It can be suppressed that the tube is cut.

In the joint of the fourth aspect, the tube can be prevented from being cut, and the tube can be prevented from coming off.

With regard to the joint of the fifth aspect, on the one hand, the possibility of the tube being cut can be further reduced, and on the other hand, the ring is trapped with respect to the tube to secure the tensile strength.

In the joint of the sixth aspect, it is possible to more reliably suppress the ring from being in contact with the inner peripheral portion of the nut while maintaining the elastic state to cut the tube.

In the joint of the seventh aspect, the tube can be more reliably suppressed from being cut.

With the joint of the eighth aspect, it is possible to more reliably suppress the tube from being cut, and it is possible to more reliably suppress the falling of the tube or the leakage of the fluid.

For the joint of the ninth aspect, it is possible to suppress the situation in which the ring is forgotten to be installed.

The joint assembly of the tenth aspect can be transported by miniaturization.

20‧‧‧ body

21a‧‧‧Outer sloped surface

21b‧‧‧ inside inclined surface

22‧‧‧ pipe joint

23‧‧‧ Body threading

24‧‧‧ Body Operations Department

25‧‧‧Installation side thread

26‧‧‧through holes

30, 230‧‧‧ nuts

31‧‧‧Insert end

32‧‧‧Outer tubular section

33‧‧‧ Nut Operation Department

34‧‧‧ Nut thread

35‧‧‧ Nuts and Tubes

36‧‧‧Reducing section

37‧‧‧Departed

38‧‧‧Bend

70, 270‧‧" ring

71‧‧‧ inner surface

72‧‧‧ outer surface

73‧‧‧1st side

74‧‧‧2nd side

75‧‧‧1st inclined surface inside

76‧‧‧1st inclined surface on the outside

77‧‧‧2nd outer inclined surface

78‧‧‧2nd inner inclined surface

90‧‧‧ tube

100‧‧‧ joint

150‧‧‧Connector assembly

Θ1, θ2‧‧‧ tilt angle

A, B, C, D‧‧‧ distance

A1, a2, a3, a4‧‧‧ length

A5‧‧‧Inner diameter

A6‧‧‧diameter

A7‧‧‧ outside diameter

A8‧‧‧ interval

B1‧‧‧Inner diameter

B2‧‧‧ outside diameter

B3‧‧‧ thickness

B4, b5‧‧‧ sloped surface

C1‧‧‧ outside diameter

C2, c3, c4, c5‧‧‧ length

C6, c7‧‧‧ inner diameter

C8, c9, c10‧‧‧ length

Fig. 1 is an exploded perspective view showing the outline of the joint and the joint assembly of the embodiment.

Figure 2 is a side view of the body.

Figure 3 is a side cross-sectional view of the body.

Fig. 4 is a view showing the body viewed from the side opposite to the side on which the tube is inserted in the axial direction.

Figure 5 is a side view of the loop.

Figure 6 is a side view of the nut.

Figure 7 is a side cross-sectional view of the nut.

Fig. 8 is a view of the nut viewed from the side of the reduced diameter portion in the axial direction.

Figure 9 is a side cross-sectional view showing a state in which a ring and a nut are attached to a tube.

Fig. 10 is a side cross-sectional view showing a state in which a tube for expanding a front end is coupled to a main body.

Figure 11 is a side cross-sectional view showing a state in which a nut is screwed with respect to the body.

Fig. 12 is a schematic side sectional view showing a state in which a joint is fixedly attached to a pipe.

Fig. 13 is an enlarged schematic cross-sectional view showing a state in which a joint is fixedly attached to a pipe.

Fig. 14 is an enlarged schematic cross-sectional view showing a side view showing another example of a state in which a joint is fixed to a pipe.

Fig. 15 is an enlarged schematic cross-sectional view showing a state in which a joint is fixedly attached to a pipe.

Fig. 16 is a side sectional view showing a state in which the joint of the other embodiment (7-1) is connected and fixed.

Fig. 17 is a side sectional view showing a state in which the joint of another embodiment (7-2) is connected and fixed.

Hereinafter, the joint and the joint assembly of one embodiment will be described. The joint and joint assembly system described below are for illustrative purposes, and are not limited thereto.

(1) Joint and joint assembly

The joint of the present embodiment is a joint that connects the tube, and includes a body, a nut, and a ring. The joint assembly system is constructed by attaching and fixing a joint to a pipe.

(2) tube

A tubular member formed of a resin on at least the inner side surface of the tube.

The surface of at least the radially inner side of the tube may be formed of a resin, and for example, the tube may be a layer containing a metal or the like. Further, the surface on the radially inner side and the surface on the radially outer side may be formed of a resin, and the intermediate layer may be formed of a metal. Preferably, the tube comprises A resin composition.

The fluid passing through the inside of the tube is not particularly limited, and examples thereof include high-temperature water such as an acid, an alkali, a solvent, and hot spring water, marine water, and industrial waste liquid. Examples of the acid include hydrochloric acid, nitric acid, hydrofluoric acid, sulfuric acid, and phosphoric acid. Examples of the base include organic amines such as ammonia water and monoethanolamine, sodium hydroxide, and potassium hydroxide. The solvent may, for example, be an alcohol such as methanol or propanol or an organic solvent such as toluene.

The state of the fluid passing through the inside of the tube can also be in a pressurized state. In the state where the fluid is pressurized, leakage from the joint portion is often a problem, but the joint of the present embodiment can suppress leakage even when the pressurized fluid flows inside.

On the one hand, the pipe ensures more flow through the internal fluid, and on the other hand, the construction workability is good, and the inner diameter is preferably 28.0 mm or more and 66.0 in a state where the connection is not fixed and there is no force. Below mm, more preferably 45.0 mm or more and 55.0 mm or less. The outer diameter of the tube is preferably greater than 38.1 mm (1.5 inches), more preferably greater than 50.8 mm (2.0 inches). Further, the outer diameter of the tube is preferably 70.0 mm or less. Further, the outer diameter of the tube is more preferably 52.0 mm or more and 62.0 mm or less.

The thickness of the tube is preferably 2.5 mm or more and 4.0 mm or less, more preferably 3.0 mm or more and 3.5 mm or less.

The bending radius of the tube is preferably 0.3 m or more and 3.0 m or less, more preferably 0.5 m or more and 1.5 m or less. Furthermore, the bending radius of the tube is the radius before the tube is bent (non-destructive) when the tube is bent into an arc shape.

Further, if the thickness of the tube is increased, the tube can be made difficult to break, but the bending radius tends to be long. When the bending radius is long, the entire length of the tube becomes long, and it becomes difficult to carry it to the site. Therefore, it is necessary to carry it into a short plurality of roots, but in this case, the connection work at the site becomes complicated, and the joint portion is complicated. An increase in the number also causes the problem of leakage to become significant. Therefore, in order to ensure the ease of handling of the pipe, and to ensure the winding of the construction site For example, the thickness of the tube is preferably 1.0 mm or more and 10.0 mm or less, and the bending radius of the tube is 0.3 m or more and 1.5 m or less.

In order to improve the ease of construction when the joint is fixed to the joint, it is preferred to heat the tube at the end of the joint.

The resin constituting the tube is preferably a resin having chemical resistance. Examples of the resin having chemical resistance include PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), and PTFE (polytetrafluoroethylene). And mixtures of such. Among them, the resin constituting the tube is preferably PFA from the viewpoints of resistance to liquid, cracking resistance, heat resistance, and mechanical properties that are difficult to break even when bent. The melting point of the resin obtained by DSC (Differential Scanning Calorimetry) is preferably 260 ° C or more and 310 ° C or less, more preferably 295 ° C or more and 310 ° C or less. PFA having a melting point of 295 ° C or higher is not excessively soft, so that deformation of the flared portion can be suppressed and the tube can be prevented from falling off. Further, PFA having a melting point of 310 ° C or less is excellent in crack resistance, and it is difficult to cause cracking in the flared portion. The resin has a modulus of elasticity measured according to ASTM D638 of preferably 300 MPa or more and 800 MPa or less, more preferably 400 MPa or more and 800 MPa or less.

Further, the surface roughness of the tube is preferably 0.001 or more and 2.0 or less. Here, the measurement of the surface roughness here was carried out using SURFTEST SV-600 manufactured by Mitutoyo, and the arithmetic mean roughness Ra (μm) of the outer surface of the tube was measured in accordance with JIS B0601-1994.

(3) Ontology

The main body has a pipe coupling portion and a body screw portion, and is formed with a through hole extending in the axial direction.

The main body threaded portion is configured to be disposed on the inner side in the axial direction with respect to the pipe joint portion, and has an outer diameter larger than the outer diameter of the pipe joint portion and screwed to the nut thread portion of the nut.

The body may further have a mounting side threaded portion and a body operating portion. The mounting side threaded portion is configured to be disposed at the end opposite to the side where the tube connecting portion is provided in the axial direction The outer peripheral surface of the joint is screwed to the thread of the member to which the joint is attached. The body operating portion is disposed between the body thread portion and the mounting thread portion in the axial direction when the nut is screwed into the body by a portion sandwiched by a wrench or a human finger. The body operating portion has a polygonal shape or a deformed shape when viewed in the axial direction.

The tube connecting portion is formed in a cylindrical shape on one end side of the body. Since the tube connecting portion is attached to the tube, it is covered from the radially outer side by the inner surface of the tube.

The main body threaded portion is provided on the outer peripheral surface so as to be larger than the outer diameter of the pipe joint portion.

Preferably, the tube connecting portion of the main body is provided with a tube insertion end at an end portion on the outer side in the axial direction. The tube insertion end has a radially outer insertion portion configured to be outward toward the axial direction, the radially outer portion being located radially inward, and the radially inner insertion portion being configured to be outward toward the axial direction and radially inward The part is located radially outward. The radially outer insertion portion may be configured by the outer inclined surface, or may be configured to smoothly bend the outer side R portion by bulging outward in the axial direction and outward in the radial direction. When the radially outer insertion portion is configured by the outer inclined surface, the smaller angle between the outer inclined surface and the axial direction in the cross-sectional shape in the axial direction is not connected and fixed. In the state of any force action, it is preferably 30 degrees or more and 60 degrees or less. It is preferable that the radially inner insertion portion is not constituted by the R portion which is smoothly curved due to the outer side in the axial direction and is bulged radially inward, and is more preferably constituted by the inner inclined surface. The reason for this is that if the radially inner insertion portion is constituted by the R portion, there is a state between the inner surface of the tube and the R portion of the radially inner insertion portion in a state in which the joint is fixedly coupled to the tube. The stagnation of fluid retention. When the radially inner insertion portion is formed by the inner inclined surface, the smaller angle between the inner inclined surface and the axial direction in the cross-sectional shape in the axial direction is not connected and fixed. In the state of any force action, it is preferably 30 degrees or more and 70 degrees or less. By setting the angle to 30 degrees or more, it is possible to prevent the thickness of the front end of the pipe joint portion from being thinned and the strength is lowered, and when the joint is fixedly attached to the pipe, it is easy to avoid by the ring or the pipe. Squeeze inside, Pour into the radial inside. Moreover, by setting the angle to 70 degrees or less, it is possible to suppress the retention of the fluid generated in the gap formed between the inner inclined surface of the pipe connecting portion and the inner surface of the pipe.

The position of the boundary portion between the radially outer insertion portion and the radially inner insertion portion on the pipe joint portion of the main body is preferably within a range of the thickness of the pipe joint portion, and is located radially inward of the pipe joint portion. . Further, the diameter of the circle formed by the boundary portion is preferably smaller than the inner diameter of the ring. This is because, in a state in which the joint is fixedly coupled to the pipe, the shape of the front end of the boundary portion of the pipe joint portion is prevented from being inserted into the thickness direction of the pipe with respect to the pipe, and it is difficult to cause the pipe to be cut. In the case where the radially outer insertion portion is configured by the outer inclined surface and the radially inner insertion portion is configured by the inner inclined surface, the outer inclined surface and the inner side in the axial direction cross-sectional shape The smaller angle among the angles formed by the inclined faces is preferably 80 degrees or more, more preferably 90 degrees or more, in a state in which it is not connected and fixed without any force. The reason for this is that the shape of the front end of the boundary portion of the pipe joint portion does not become an excessively sharp shape. Further, the ring is provided on the main body side and has an inclined surface on the inner side in the radial direction, and when the pipe connecting portion includes the outer inclined surface, the inclination angle of the inclined surface of the ring in the cross-sectional shape in the axial direction is The inclination angle of the inclined surface on the outer side of the pipe joint portion is preferably not less than 10 degrees, more preferably uniform.

Further, the diameter of the circle formed by the boundary portion of the pipe joint portion is preferably smaller than the outer diameter of the pipe and larger than the inner diameter of the pipe. Thereby, in a state in which the pipe is fixed to the joint, the pipe joint portion of the body can be prevented from being poured into the radially inner side, and the pipe joint portion of the body can be prevented from becoming a resistance to fluid flow, and the pipe can be made difficult to be Cut off.

The outer diameter of the tube connecting portion of the main body is preferably 1.05 times or more and 1.10 times or less the outer diameter of the tube in a state where it is not connected and fixed without any force.

The thickness of the radial direction of the tube connecting portion of the main body is preferably 1.5 times or more and 1.8 times or less the thickness of the tube in a state where it is not connected and fixed without any force.

The body may comprise a plurality of parts, but preferably comprises a resin composition. on The resin constituting the main body is preferably a resin having chemical resistance similarly to the tube. Examples of such a resin include PTFE (polytetrafluoroethylene) or PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer). The melting point of the resin determined by DSC (differential scanning calorimetry) to determine the peak top is preferably 320 ° C or more and 330 ° C or less, more preferably 327 ° C. Here, it is not particularly limited. For example, in the raw material of the PTFE molded product, the powdery PTFE raw material powder can be compressed and solidified in a mold, and then fired in a hot air environment furnace at 360° C. or higher and 380° C. or lower. When the processed product is obtained by mechanical processing, if the baking of the raw material powder is insufficient, the melting point is higher than 327 ° C, which may cause defects such as deterioration in mechanical properties and the like. Further, the resin has a modulus of elasticity measured according to ASTM D638 of preferably 400 MPa or more and 800 MPa or less.

Further, the surface roughness of the body is preferably 0.001 or more and 2.0 or less. Here, the measurement of the surface roughness here is performed by measuring the surface of the radially outer insertion portion of the body at the front end of the pipe joint portion in the substantially axial direction instead of the circumferential direction. In addition, the measurement of the surface roughness here was measured using the SURFTEST SV-600 by Mitutoyo, and the arithmetic mean roughness Ra (μm) of the surface of the said radial outer insertion part by JIS B0601-1994.

(4) Nut

The nut has a nut thread portion, a reduced diameter portion, and a contacted portion.

The nut thread portion is configured to be screwed into the body screw portion in a state in which the tube connecting portion of the main body is inserted into the other end side in the axial direction from the one end side (the insertion opening side) in the axial direction.

The reduced diameter portion is provided on the other end side in the axial direction (on the side opposite to the insertion opening side), and is smaller than the inner diameter of the nut thread portion.

The abutted portion is formed to be one end side (the insertion opening side) in the axial direction with respect to the reduced diameter portion. In the entire abutment portion nut, a portion that abuts against one of the rings in a state where the tube is coupled and fixed to the joint.

The nut is preferably configured such that the thickness of the radial direction is thicker than the portion in the vicinity of the opening side on the insertion side in the axial direction.

Preferably, the nut is formed in a cylindrical shape of a nut having a cylindrical shape extending in the axial direction between the nut thread portion and the reduced diameter portion in the axial direction. Regarding the radial thickness of the nut portion of the nut of the nut, it is necessary to make the tube not fall off even if the ring below expands beyond the elastic state so that the outer diameter portion of the ring comes into contact with the nut. Since the deformation of the nut itself is suppressed, it is preferably 1.5 times or more and 4.0 times or less, more preferably 2.5 times or more and 3.5 times or less the thickness of the tube.

The nut may also have a nut operating portion that is formed in a polygonal shape or a deformed shape when viewed in the axial direction. The nut operating portion is a portion that is held by a wrench or a human finger when the nut is screwed into the body.

The shape of the abutted portion is not particularly limited. However, in a state in which the tube is coupled and fixed to the joint, it is preferably in a shape corresponding to one of the abutting rings. For example, in a state in which the tube is fixed to the joint, the shape of one of the abutting rings is a surface shape, and when the normal direction of the surface is an axial direction, it is preferable that the abutted portion also has a surface shape. Further, the normal direction of the surface is formed to be an axial direction.

The nut preferably comprises a resin composition. The resin constituting the nut is preferably a resin having chemical resistance similarly to the tube or the body. Examples of such a resin include PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PCTFE (polychlorotrifluoroethylene), PVDF (polyvinylidene fluoride), and ETFE (ethylene-tetrafluoroethylene). Ethylene copolymer), PPS (polyphenylene sulfide), and mixtures thereof. Among them, PFA is preferably included. The melting point of the resin determined by DSC (differential scanning calorimetry) to determine the peak top is preferably 295 ° C or more and 310 ° C or less. PFA having a melting point of 295 ° C or higher is not excessively soft, so that deformation can be suppressed and the tube can be prevented from falling off. Further, PFA having a melting point of 310 ° C or less is excellent in cracking resistance, so that cracking is less likely to occur. The resin has a modulus of elasticity measured according to ASTM D638 of preferably 400 MPa or more and 800 MPa or less.

Further, the nut is preferably transparent or translucent from the viewpoint of confirming whether or not the ring is located inside (whether or not the ring is forgotten) in a state in which the tube is fixed to the joint.

(5) ring

The ring-shaped member is disposed in a space radially inward of the threaded portion of the nut of the nut, and has an annular modulus higher than that of the tube and is used to abut against the abutted portion of the nut. At least one of the rings can be used on the joint, and a plurality of them can be used. When a plurality of cases are used, the ring that abuts against the abutting portion of the nut may be different from the ring that abuts the outer surface of the tube.

In a state in which the body, the nut, and the ring are coupled with respect to the tube, the ring has an elastic modulus that can achieve the following properties. That is, in the case where the ring is in the state of the elastic region, the ring can press the tube from the radially outer side toward the radially inner side by the stress of itself. Moreover, in the case where the ring is in a state beyond the elastic region, the expanded ring is pressed radially inward by the radially inner side surface of the nut, whereby the tube can be pressed radially outward from the radially outer side . Adjusting the elastic modulus of the ring in a manner higher than the elastic modulus of the tube, whereby the ring is radially oriented in a state in which one of the tubes is sandwiched by the end of the tube connecting portion of the ring and the body The outer side expands and elastically deforms, so that the elastic force acts to press the tube from the radially outer side toward the radially inner side. Thereby, the tube can be firmly fixed so that the tube is hard to fall off, and leakage of the fluid passing through the inside of the tube can be suppressed. Moreover, in a state in which the nut is screwed to the body and the joint is fixed to the tube, even if some external force acts on the tube, since the elastic modulus of the ring is adjusted as described above, The tube is difficult to fall off. Further, in a state in which the joint is fixed to the tube and some external force acts on the tube, the ring can be deformed to be further expanded and beyond the elastic region. Thereby, it is possible to suppress cutting by excessively fastening the tube. Further, even in the case where the ring expands and deforms to be in a state beyond the elastic region, the radially outer portion of the expanded ring abuts against the radially inner side surface of the nut, and by the inner circumference of the nut Partially pressed toward the inside in the radial direction. In this way, the ring that is pressed radially inward by the nut can be used to The radially outer side is press-fastened and fixed toward the radially inner side, so that the tube is hard to fall off, and leakage of the fluid passing through the inside of the tube can be suppressed.

Further, since the ring system is used as a member different from the nut, the nut rotates around the tube at the stage of screwing the nut to the body, but the rotation of the ring is suppressed. Thereby, it is possible to suppress the occurrence of scratches on the outer circumference of the tube due to the rotation of the ring, thereby protecting the tube from being cut.

In the shape of the ring, the shape of the cross section in the normal direction of the circumferential direction is preferably a rectangular shape, and at least the radially inner side and the main body side of the axial direction are chamfered or have rounded shapes. . The chamfered shape or the portion having the rounded shape of the radially inner side of the ring and the portion on the body side in the axial direction is preferably 0.3% or more and 40% or less of the width of the radial direction of the loop. Further, the portion of the width of the loop in the axial direction of 1% or more and 40% or less is more preferably 3% or more and 29% or less of the width of the radial direction of the loop, and 2% of the width of the loop in the axial direction. The portion of the above-mentioned range of 25% or less is more preferably 3% or more and 10% or less of the width of the radial direction of the ring, and is a portion of 2% or more and 10% or less of the width of the ring in the axial direction. This range is preferred for the following reasons. That is, in a state in which the joint is fixedly coupled to the pipe, the ring is in contact with the pipe at a portion on the radially inner side of the ring and on the body side in the axial direction. Further, in the joint, in the case of the chamfered shape or the shape with rounded corners on the radially inner side of the ring and the portion on the body side in the axial direction (0.3 in the radial direction of the ring) When the ratio of % or more and the width of the axial direction of the ring is 1% or more, even if a ring having a higher elastic modulus is used, it is difficult to apply a partial pressure to the tube from the ring. . Thereby, it is possible to suppress the tube from being cut. Further, the portion in which the ring is chamfered or has a rounded shape is set to be 40% or less of the width of the ring in the radial direction and 40% or less of the width of the ring in the axial direction. This makes it possible to make the contact area with the surface on the outer side of the tube not too large, so that the force which is pressed against the tube by the ring can be suppressed from being dispersed, and the tube can be easily detached. In particular, the chamfered shape of the portion on the radially inner side of the ring and the portion on the body side in the axial direction or the portion of the radius of the portion having the rounded shape is 3% or more and 29% or less of the width of the radial direction, and 2% or more and 25% or less of the width of the axis of the tether In this case, on the one hand, the possibility of the tube being cut off can be further reduced, on the one hand the ring is trapped relative to the tube to ensure tensile strength.

Further, the pipe is attached in a state of being inclined with respect to the axial direction so as to be along the outer side surface of the radially outer insertion portion of the body, so that the portion of the inner side of the ring and the body side of the axial direction are chamfered. The portion other than the shape or the portion having the rounded shape is pressed against the tube in a direction in which the thickness of the tube is narrowed with respect to a portion of the outer surface of the tube which is inclined with respect to the axial direction. On the other hand, the radially outer insertion portion of the main body is pressed against the tube in a direction in which the thickness of the tube is narrowed with respect to a portion of the inner surface of the tube which is inclined with respect to the axial direction. Thereby, the tube is sandwiched by the radially inner side of the ring and the portion on the body side in the axial direction and the radially outer insertion portion of the body. The portion of the tube that is clamped is thinner than the other portions of the tube. Further, the portion closer to the inner portion than the tube to be clamped is thicker than the portion where the tube is clamped. Therefore, it is difficult for the thick portion of the tube to pass through the portion of the radially inner side of the ring and the portion on the body side in the axial direction and the radially outer insertion portion of the body, so that the tube is difficult to fall off in front of the tube. .

Furthermore, in the case where the chamfered shape is formed into a ring, the smaller of the angle formed by the normal of the chamfered surface and the radial direction of the ring is preferably 20 degrees or more and 70. Below the degree, it is more preferably 30 degrees or more and 60 degrees or less, and particularly preferably 45 degrees.

Regarding the size of the outer diameter of the ring, when the ring is pressed outward in the radial direction and expanded, it is preferably hard to break, and in the state beyond the elastic region, abuts against the inner side of the nut, specifically, Preferably, the inner diameter of the nut portion of the nut of the nut is 85.0% or more and 99.9% or less, more preferably 98.0% or more and 99.9% or less. Further, the gap between the outermost portion of the outer diameter of the ring and the inner diameter of the nut portion of the nut of the nut is preferably 0.1 mm or more and 2.0 mm or less in a state where the outer diameter of the nut portion of the nut of the nut is not connected and fixed without any force. More preferably, it is 0.2 mm or more and 1.0 mm or less.

The inner diameter of the ring is preferably 1.001 times or more and 1.04 times or less the outer diameter of the tube, and more preferably 1.001 times or more and 1.01 times or less the outer diameter of the tube.

The thickness of the radial direction of the ring is preferably thicker than the thickness of the tube. Specifically, the thickness of the radial direction of the ring is preferably 1.2 times or more and 2.5 times or less the thickness of the tube, more preferably 1.2 times or more and 2.0 times or less, and more preferably 1.4 times or more and 1.8 times the thickness of the tube. the following.

The width in the axial direction of the ring is not particularly limited. For example, it is preferably 0.5 times or more and 4 times or less, more preferably 1.0 times or more and 2.0 times or less the thickness of the radial direction of the ring.

The ring preferably comprises a resin composition. The resin constituting the ring is preferably a resin having chemical resistance similarly to the tube, the body, or the nut. Examples of such a resin include PVDF (polyvinylidene fluoride), PCTFE (polychlorotrifluoroethylene), ETFE (ethylene-tetrafluoroethylene copolymer), PPS (polyphenylene sulfide), and the like. a mixture of such. These resin compositions may contain a filler, but preferably do not contain glass fibers. As such a resin, preferred is PVDF or PCTFE. The melting point of the resin determined by DSC (differential scanning calorimetry) to determine the peak top is preferably 130 ° C or more and 290 ° C or less, more preferably 160 ° C or more and 230 ° C or less. When the melting point is within this range, the ring does not become excessively soft, so that the deformation can be suppressed, the tube can be prevented from falling off, and the crack resistance is excellent, so that cracking is less likely to occur. The elastic modulus of the resin measured according to ASTM D638 is preferably 500 MPa or more and 4000 MPa or less, preferably higher than the elastic modulus of the nut, more preferably higher than the elastic modulus of the tube, and more preferably 1000 MPa or more. 2500MPa or less.

Further, when the elastic modulus of the nut is lower than the elastic modulus of the ring, in a state in which the joint is fixed to the tube, even if the ring is deformed beyond the elastic region, it becomes the outer peripheral portion of the ring. When the inner peripheral portion of the nut is in a state of being pressed toward the inner side in the radial direction, since the elastic modulus of the nut is not the degree of the elastic modulus of the ring, the tube can be prevented from being excessively tight. Solid, thereby inhibiting the tube from being cut.

Further, depending on whether the nut is transparent or translucent, the ring is preferably opaque or colored, from the viewpoint of forgetting to mount the ring.

Further, the surface roughness of the ring is preferably 0.001 or more and 8.0 or less. Again, here The surface roughness was measured by measuring the surface of the portion of the ring which is located at the position closest to the radially outer insertion portion of the body in the fixed state in the substantially axial direction rather than the circumferential direction. Here, the measurement of the surface roughness here was carried out using SURFTEST SV-600 manufactured by Mitutoyo, and the arithmetic mean roughness Ra (μm) of the surface of the above-mentioned portion in the ring was measured in accordance with JIS B0601-1994.

(6) Relationship between components

The relationship between the materials constituting the respective members, that is, the resin constituting the tube, the resin constituting the ring, and the resin constituting the nut, is particularly preferably a resin which is a PFA, and a resin which constitutes a ring is PVDF or PCTFE. The resin constituting the nut is PFA. Further, in the combination, it is particularly preferred that the resin constituting the body is PTFE or PFA.

Moreover, the relationship between the shape and the size of each member, that is, in the state in which the ring is in the elastic region in a state in which the body, the nut, and the ring are coupled to the tube, the inner peripheral portion of the nut In the case where the inner diameter of the portion located radially outward is the largest portion and the outer diameter of the portion where the outer diameter of the ring is the largest is set to Y with respect to the largest portion of the outer diameter of the ring, The value of the formula (XY)/Y indicating the length of the portion corresponding to X and Y in the state in which the nut and the ring are connected without any force is preferably 0.003 or more and 0.020 or less, more preferably 0.0055 or more and 0.0121 or less. More preferably, it is 0.0055 or more and 0.0090 or less.

Further, the relationship between the shape and the size of each member, that is, the state in which the body, the nut, and the ring are coupled to the tube, in the state in which the ring is in the elastic region, is in the inner peripheral portion of the nut. The inner diameter of the portion located radially outward is set to X with respect to the largest portion of the outer diameter of the ring, the outer diameter of the portion where the outer diameter of the ring is the largest is set to Y, and the thickness of the tube is set to Z. In the case of the case where the nut, the ring, and the tube are connected to each other without any force, the value of the formula (XY)/Z which is equivalent to the length of the portion corresponding to X, Y, and Z is preferably 0.04. The above is 0.30 or less, more preferably 0.05 or more and 0.25 or less.

[Examples]

Fig. 1 is a schematic exploded perspective view showing the appearance of the joint and the joint assembly of the first embodiment.

The joint assembly 150 is configured by connecting and fixing the joint 100 to the tube 90.

The joint 100 includes a body 20, a ring 70, and a nut 30.

In the state in which the tube 90 is connected to the tube connecting portion 22 (described below) of the body 20, the nut 30 is screwed with respect to the body 20, thereby being located in the radial direction of the nut 30. The ring 70 on the radially inner side of the inner tube 90 is sandwiched and fixed to the tube insertion end 21 (described below) of the body 20.

Hereinafter, each member will be described in detail separately.

(tube 90)

The tube 90 comprises a PFA resin having an outer diameter of 57.4 mm, an inner diameter of 50.8 mm, and a radial thickness of 3.3 mm. The bend radius of the tube 90 is 0.91 m, and the elastic modulus of the tube 90 is 450 MPa.

(body 20)

As shown in the side view of FIG. 2, the main body 20 includes a tube insertion end 21, a tube coupling portion 22, a body thread portion 23, a body operation portion 24, a mounting side screw portion 25, and a through hole 26. The tube insertion end 21 constitutes the front end of the side of the insertion tube 90. As shown in the side cross-sectional view of Fig. 2, the tube insertion end 21 has an outer inclined surface 21a which is formed so that the radially outer side portion is located radially inward as it goes outward in the axial direction, and the inner inclined surface 21b is configured as The more toward the outer side in the axial direction, the radially inner portion is located radially outward. The tube connecting portion 22 is a portion in which the outer surface is in contact with the inner surface of the tube 90 in a state in which the tube 90 is inserted, and is configured to extend from the tube insertion end 21 in a cylindrical shape. The main body thread portion 23 is provided on the side opposite to the tube insertion end 21 side with respect to the pipe coupling portion 22, and has an outer diameter larger than the outer diameter of the pipe coupling portion 22, and a nut thread portion of the nut 30 described later. 34 screwing. The main body operating portion 24 is a portion that is held by a wrench or a human finger when the nut 30 is screwed into the main body 20, and is provided on the opposite side of the pipe coupling portion 22 side with respect to the main body screw portion 23. The body operating portion 24 is along the axial direction of FIG. As seen from the top view of the observation, when viewed in the axial direction, it has a shape in which the sides of the rectangle are smoothly connected. The mounting side screw portion 25 has a thread for screwing with respect to a mounting object not shown. The through hole 26 is a hole that penetrates the body 20 in the axial direction.

As shown in Fig. 2, with respect to the length in the axial direction, the total length a1 of the tube insertion end 21 and the tube coupling portion 22 is 28.0 mm, the length a2 of the body thread portion 23 is 40.0 mm, and the length a3 of the body operation portion 24 is 20.0. Mm, the length a4 of the mounting side thread portion 25 is 30.0 mm. Further, as shown in Fig. 3, the inner diameter a5 of the through hole is 20.8 mm, the diameter a6 of the circle formed by the boundary portion between the outer inclined surface 21a and the inner inclined surface 21b is 54.8 mm, and the outer diameter a7 of the pipe connecting portion 22 is 61.8. Mm, either on a concentric circle. Further, in the axial section, the inclination angle θ1 of the outer inclined surface 21a with respect to the axial direction is 45 degrees, and the inclination angle θ2 with respect to the inner inclined surface 21b of the axial direction is 45 degrees. Further, in the axial section, the angle formed by the inclined surface of the outer inclined surface 21a and the inclined surface of the inner inclined surface 21b is 90 degrees. Further, as shown in Fig. 4, the distance a8 between the opposing faces of the main body operating portion 24 is 80.0 mm.

The body 20 is comprised of PTFE.

The body 20 has a modulus of elasticity of 460 MPa.

(ring 70)

As shown in FIG. 5, the ring 70 has an inner surface 71, an outer surface 72, a first side surface 73, a second side surface 74, an inner first inclined surface 75, an outer first inclined surface 76, an outer second inclined surface 77, and An annular member of the inner second inclined surface 78.

The inner surface 71 constitutes the innermost surface of the ring 70 in the radial direction by a surface extending in a cylindrical shape in parallel with the axial direction. The outer surface 72 constitutes the outermost surface of the ring 70 in the radial direction by a surface extending in a cylindrical shape in parallel with the axial direction. The first side surface 73 is a circumferential surface in which the axial direction is the normal direction, and constitutes one end side of the ring 70 in the axial direction. The second side surface 74 is a circumferential surface in which the axial direction is the normal direction, and constitutes the other end side of the ring 70 in the axial direction. The inner first inclined surface 75 is an inclined surface that connects the inner surface 71 and the first side surface 73, and is formed to have an inclined surface so as to be radially outward as it approaches the first side surface 73 side in the axial direction. Outside The first inclined surface 76 is an inclined surface that connects the outer surface 72 to the first side surface 73, and is formed to have an inclined surface so as to be located radially inward in the axial direction as it approaches the first side surface 73 side. The outer second inclined surface 77 is an inclined surface that connects the outer surface 72 and the second side surface 74, and is formed to have an inclined surface so as to be located radially inward in the axial direction as it approaches the second side surface 74 side. The inner second inclined surface 78 is an inclined surface that connects the inner surface 71 and the second side surface 74, and is formed to have an inclined surface so as to be radially outward as it approaches the second side surface 74 side in the axial direction.

The inner diameter b1 of the ring 70 is 57.7 mm, the outer diameter b2 is 68.5 mm, and the thickness b3 in the axial direction is 8.0 mm. Further, the inner first inclined surface 75, the outer first inclined surface 76, the outer second inclined surface 77, and the inner second inclined surface 78 have a smaller angle of inclination with respect to the inclined surface in the axial direction. Both are 45 degrees. Further, each of the inner first inclined surface 75 and the inner second inclined surface 78 has a shape and a size which are formed by obliquely cutting in the axial direction by a width of 0.3 mm in the axial direction and a width of 0.3 mm in the radial direction. Inclined surface (refer to b4, b7 of Fig. 5). Any one of the outer first inclined surface 76 and the outer second inclined surface 77 has an inclined surface having a shape and a size which is obliquely removed by a width of 0.5 mm in the axial direction by a width of 0.5 mm in the axial direction. Refer to b5, b6) of Figure 5.

Further, since the ring 70 has a symmetrical shape, the same result can be obtained even if one of the axial directions faces the body 20 side. Therefore, in the present embodiment, the case where the first side surface 73 faces the body 20 side is taken as an example. Be explained. In this case, it is mainly contributed to the portion of the tube 90 that is sandwiched between the body 20 and the inner first inclined surface 75. Here, the inclination angle of the inner first inclined surface 75 with respect to the axial direction and the inclination angle with respect to the axial direction of the outer side inclined surface 21a of the main body 20 are common at 45 degrees.

Ring 70 contains PVDF.

The elastic modulus of the ring 70 is 2200 MPa.

(nut 30)

As shown in the side view of FIG. 6, the side cross-sectional view of FIG. 7, and the side view of the reduced diameter portion in the axial direction of FIG. 8, the nut 30 includes an insertion end portion 31 and an outer cylindrical shape. unit 32. The nut operating portion 33, the nut thread portion 34, the nut cylindrical portion 35, the reduced diameter portion 36, the abutted portion 37, and the curved portion 38.

The insertion end portion 31 constitutes an insertion-side front end when the nut 30 is inserted into the body 20, and has a shape that slightly expands outward in the radial direction. The outer tubular portion 32 extends in a cylindrical shape in the axial direction. The nut operating portion 33 is a portion that is sandwiched by a wrench or a human finger when the nut 30 is screwed into the body 20, and is formed opposite to the insertion end 31 side in the axial direction with respect to the outer cylindrical portion 32. side. As shown in FIG. 8, the nut operating portion 33 has a shape in which the corners of the hexagonal shape are circular when viewed in the axial direction. When the nut 30 is inserted into the main body 20 and screwed, the nut thread portion 34 is formed on the insertion end portion 31 side of the nut 30 so as to be screwed from the radially outer side with respect to the main body screw portion 23. The reduced diameter portion 36 extends from the end portion on the side opposite to the insertion end portion 31 side toward the insertion end portion 31 side, and constitutes a cylindrical portion on the inner side of the nut 30. The nut cylindrical portion 35 forms a cylindrical portion on the inner side of the nut 30 in such a manner that the nut thread portion 34 and the reduced diameter portion 36 are connected in the axial direction, and constitutes a radial direction of the reduced diameter portion 36 in the radial direction. The outer side is the radially inner side of the nut thread portion 34. The abutted portion 37 includes an end portion on the side of the insertion end portion 31 of the reduced diameter portion 36 and an end portion on the side opposite to the insertion end portion 31 side of the nut cylindrical portion 35 so as to be radially expanded. Face (toward the side of the insertion end 31). The bent portion 38 is provided in an R-shaped portion on a portion where the end portion on the side opposite to the insertion end portion 31 side of the nut cylindrical portion 35 is connected to the abutted portion 37.

As shown in FIG. 6, the nut 30 has an outer diameter c1 of the insertion end portion 31 of 95.0 mm, and a length c2 in which the portions having the rounded shape opposed to each other in the nut operation portion 33 are connected to each other by a length c2 of 90.0 mm. Further, as shown in Fig. 6, the length c3 of the insertion end portion 31 is 41.5 mm, the length c4 of the outer cylindrical portion 32 is 31.0 mm, and the length c5 of the nut operation portion 33 is 5.0 mm. Further, as shown in Fig. 7, the inner diameter c6 of the nut cylindrical portion 35 is 69.0 mm, and the inner diameter c7 of the reduced diameter portion 36 is 58.0 mm. Further, as shown in Fig. 6, with respect to the length in the axial direction, the length c8 of the nut thread portion 34 is 34.0 mm, the length c9 of the nut cylindrical portion 35 is 32.5 mm, and the length c10 of the reduced diameter portion 36 is 11.0 mm. . Furthermore, the curvature of the curved portion 38 is half The diameter is 0.5mm.

The nut 30 is composed of PFA.

The nut 30 has a modulus of elasticity of 500 MPa.

(link fixed action)

In the present embodiment, the main body 20, the ring 70, and the nut 30 are fixed to the tube 90 in the following order, and the joint 100 is coupled and fixed to the tube 90.

First, the front end of the tube 90 to which the joint 100 is to be attached is inserted into the nut 30 via the reduced diameter portion 36 side, and further inserted into the ring 70 to be in a state shown in a side sectional view of Fig. 9.

Next, the inner diameter of the front end portion of the pipe 90 to which the joint 100 is to be attached is heated and expanded to the outer diameter of the pipe joint portion 22. Then, the tube connecting portion 22 of the body 20 is inserted into the inner side of the front end of the expanded tube 90 to form a state as shown in a side cross-sectional view of Fig. 10. Further, the front end of the tube 90 is set to fall within the range of the axial direction of the tube connecting portion 22.

Thereafter, the nut 30 is brought closer to the body 20 in the axial direction, and is moved to a portion where the body thread portion 23 of the body 20 and the nut thread portion 34 of the nut 30 start to be screwed together. At this time, the second side surface 74 of the ring 70 abuts against the abutted portion 37 of the nut 30 in the axial direction, and the ring 70 moves toward the body 20 side in the axial direction. Then, the nut 30 is rotated relative to the main body 20, and the nut 30 is screwed into the main body 20 so as to be in the state shown in the side sectional view of FIG. Here, the body 20 and the tube 90 are substantially integrated, and are not rotated by the rotation of the nut 30. Moreover, since the nut 30 is formed separately from the ring 70, even in the case where the nut 30 is rotated, the ring 70 is in principle moved only in the direction of the axis along the outer surface of the tube 90, and the ring 70 is in the tube 90. Does not rotate on the outer surface.

When the screwing operation of the nut 30 to the main body 20 is continued, the inner first inclined surface 75 of the ring 70 abuts against a portion of the tube 90 located in the vicinity of the outer side inclined surface 21a of the main body 20. Further, when the screwing operation of the main body 20 of the nut 30 is continued, the inner first inclined surface 75 of the ring 70 faces the portion of the tube 90 which is located near the outer side inclined surface 21a of the main body 20. The direction body 20 side is pressed. At this time, the portion of the ring 70 located in the vicinity of the inclined surface 21a on the outer side of the body 20 from the tube 90 receives a reaction force that is pushed back toward the opposite side of the body 20 side in the axial direction and a force that expands outward in the radial direction. Thereby, the ring 70 is elastically deformed to be in a state in the elastic region, whereby an elastic force acts on a portion of the tube 90 located in the vicinity of the inclined surface 21a on the outer side of the body 20. Then, at the time when the tightening torque when tightening the nut 30 becomes a value of 250 kgf ‧ cm, the screwing operation of the nut 30 to the main body 20 is completed, and the side view of FIG. 12 is formed. In the state, the joint 100 is fixedly coupled to the tube 90. In addition, the reason why the tightening torque is a value of 250 kgf ‧ cm is based on the following reasons. That is, in the case of the shape, the size, and the material of the above embodiment, the sealing property is good (the fluid passing through the inside of the tube 90 does not leak), and the tensile strength is good (the tube 90 does not self-join 100) The upper limit is obtained based on these viewpoints. Further, in the case of the shape, the size, and the material of the above-described embodiment, the pipe connecting portion 22 of the main body 20 is not excessively fastened, and the flow path is greatly narrowed, so that the flow path is greatly narrowed. From the point of view, grasp the upper limit of the value of the tightening torque. In the range of the lower limit and the upper limit of the tightening torque grasped in this manner, it is determined that the appropriate value of the screwing operation of the body 30 to the end of the nut 30 can be determined.

Furthermore, the tightening distance corresponding to the value of the tightening torque (the position of the outer surface of the nut 30, and the body) may be set in advance by the end time of the screwing operation of the nut 30 to the body 20. Judging by the change in the distance of a certain position on the outer surface of 20).

(the state of the link is fixed)

FIG. 13 is a schematic cross-sectional view showing an enlarged portion of a main portion in a state in which a joint 100 is fixed to a pipe 90.

In the state in which the connection is fixed, a radial gap is formed between the radially outer surface 72 of the ring 70 and the inner surface of the nut cylindrical portion 35 of the nut 30 located outside the radial direction. That is, the radial distance A from the center of the shaft to the outer surface 72 of the ring 70, the radial distance B from the center of the shaft to the inner surface of the nut cylindrical portion 35 of the nut 30 is more long. This gap can be confirmed, for example, in the following manner. In other words, when the nut 30 is preliminarily coated with the colored coating material or the like on the radially outer surface 72 of the ring 70, and the nut 30 is removed from the state of the connection, the nut 30 of the nut 30 is confirmed. The color of the colored paint was not observed on the inner surface of the portion 35, and it was confirmed that there was a gap in the joint-fixed state. Further, in the state in which the connection is fixed, the radial distance C from the shaft center to the boundary portion between the outer inclined surface 21a and the inner inclined surface 21b of the body 20 is larger than the diameter from the shaft center to the inner surface 71 of the ring 70. The distance D is shorter, and the boundary portion between the outer side inclined surface 21a and the inner side inclined surface 21b of the main body 20 is located within the range of the thickness of the tube 90 (the portion located radially inward of the ring 70).

Further, in the present embodiment, the state of the tightening torque is brought into a fixed state. However, in the case of the shape, the size, or the material of the present embodiment, the state of the connection may be fixed to another standard. And specific. For example, as shown in FIG. 14, the state in which the following state is connected and fixed, that is, the position s in the axial direction of the first side surface 73 of the ring 70 and the boundary between the outer inclined surface 21a and the inner inclined surface 21b of the main body 20 may be used. The distance in the axial direction of the position t of the partial axial direction is within 30% of the thickness of the radial direction of the tube 90 (one-half the difference between the outer diameter and the inner diameter in the state without any force) (negative 30%) The state above and below 30%).

(the state in which the external force acts to expand the ring)

FIG. 15 is a schematic cross-sectional view showing a state in which a joint 100 is fixed to the tube 90 and an external force is applied to the tube 90.

Here, the external force was applied using a tensile tester used in the tensile property evaluation test. Specifically, in a state where the connection is fixed, the tube 90 is stretched so that the tube 90 is separated from the joint 100 in the axial direction, and an external force acts. The tensile strength here was set to 15 MPa in accordance with the shape, size, and material of the above examples. Here, the stretching speed was set to 200 mm/min. Further, in the state in which the connection is fixed, the thickness of the tube 90 is inclined by the inner side of the first inclined surface 75 of the ring 70 and the outer side of the body 20. In the portion where the grip is 21a, the thickness becomes thin, and the thickness of the front and rear portions becomes thick. Therefore, in the state where the joint is fixed, the tube 90 is stretched in the direction away from the joint 100 in the axial direction by the tensile tester, so that the ring 70 is radially oriented by the thickened portion of the tube 90. Lateral expansion. In this manner, the ring 70 extends beyond the elastic region, and the radially outer outer surface 72 of the ring 70 comes into contact with the inner surface of the nut cylindrical portion 35 of the nut 30.

Further, the value of the tensile strength of 15 MPa as the external force is determined in consideration of the condition in which the tensile stress obtained in total is applied as follows: (i) the maximum stress of the stretching of the tube (when the tube is extended beyond the point of the falling point) (ii) the maximum stress of the fluid pressure (determined according to the specification of the highest service pressure of the tube 90); and (iii) the maximum stress of the fastening.

In a state in which the external force is further actuated to expand the ring 70, the ring 70 is in a state beyond the elastic region, and the radially outer surface 72 of the ring 70 and the nut barrel of the nut 30 located outside the radial direction are formed. The inner surface of the portion 35 is in contact. Further, the contact between the radially outer outer surface 72 of the ring 70 and the inner surface of the nut cylindrical portion 35 of the nut 30 is confirmed by the following method: as described above, the diameter of the ring 70 When the outer surface 72 is coated with a colored paint or the like in advance, and the nut 30 is removed by a tensile tester, the nut 30 is removed, and the nut 30 is confirmed in the nut 30 of the nut 30. The color of the above colored paint is produced on the inner surface. In this way, it is confirmed that the ring 70 is expanded by the external force, and the ring 70 has a contact portion with the nut cylindrical portion 35 of the nut 30 via the outer surface 72 of the ring 70, and the nut 30 is provided. The force of pressing toward the inside of the radial direction. Therefore, the ring 70 can press the tube 90 from the radially outer side toward the inner side.

(assessment)

The sample which is not connected and fixed so that the external force does not function, and the sample which is in a state in which the external force is applied after the connection is fixed are subjected to an airtight performance evaluation test, a pressure resistance performance evaluation test, a thermal cycle performance evaluation test, and And repeated evaluation of the performance evaluation test.

In the airtightness evaluation test, the entire end of the joint 100 was immersed in water in a state in which one end was sealed, and N ₂ gas was filled into the tube 90 to increase the internal pressure to 1.4 MPa. After 5 minutes, the presence or absence of air bubbles was visually confirmed. Produced. Here, the case where there is no leakage of N ₂ gas (production of bubbles) in 1 minute is taken as a pass criterion.

The pressure resistance performance evaluation test is carried out by forming a state in which one end is sealed and a hand pressing button is connected. After the water is filled in the tube 90, the internal pressure is gradually increased by a hand pressing a button, and the presence or absence of the fitting is confirmed. 90 off. A case where no omission occurred before the tube 90 was broken was used as a pass standard.

In the repeated bonding performance evaluation test, the loading and unloading operation of the pipe 90 and the joint 100 was repeated 20 times, and thereafter, the same test method as the airtightness evaluation test was carried out. After 20 times of repeated loading and unloading operation, there was also no leakage of N ₂ gas (production of bubbles) within 1 minute as a pass criterion.

In the above evaluation test, any of the samples in a state in which the external force is not functioning and the sample in a state in which the external force is applied after the connection is fixed, is acceptable in any of the tests.

(7) Other embodiments

The above-described embodiment is exemplified as one of the embodiments corresponding to the above-described embodiment. However, the embodiment is not limited thereto, and the following embodiments obtained by appropriately changing the configuration may be employed.

(7-1)

In the embodiment of the above-described embodiment, a case where the portion other than the reduced diameter portion 36 is formed by the nut thread portion 34 and the nut cylindrical portion 35 will be described as an example.

However, the embodiment is not limited thereto. For example, as shown in FIG. 16, a nut 230 may be used instead of the nut 30 of the above-described embodiment, which is such that the nut thread portion 34 of the above embodiment is axially oriented. The extension is provided up to the portion corresponding to the nut cylindrical portion 35 of the above embodiment.

(7-2)

In the embodiment of the above embodiment, the case where only one ring 70 is used is described as an example.

However, the embodiment is not limited thereto. For example, as shown in Fig. 17, a ring 270 having the same shape and size as the ring 70 of the above embodiment may be further used, so that the ring 70 and the ring 270 are axially oriented. Used in a continuous manner.

20‧‧‧ body

21a‧‧‧Outer sloped surface

21b‧‧‧ inside inclined surface

30‧‧‧ Nuts

35‧‧‧ Nuts and Tubes

37‧‧‧Departed

70‧‧‧ Ring

71‧‧‧ inner surface

72‧‧‧ outer surface

73‧‧‧1st side

74‧‧‧2nd side

75‧‧‧1st inclined surface inside

90‧‧‧ tube

A, B, C, D‧‧‧ distance

Claims (8)

A joint (100) connected to a tube (90) having at least an inner side surface made of a resin, comprising: a body (20) having: a tube joint portion (22) provided at one end, and an outer peripheral surface a body thread portion (23) having an outer diameter larger than the pipe joint portion, and a through hole (26) extending in the axial direction; and a nut (30) having a nut thread portion (34) In a state in which the tube connecting portion of the main body is inserted into the other end side in the axial direction from one end side in the axial direction, the main body screw portion can be screwed; and the reduced diameter portion (36) is provided in The other end side of the axial direction is smaller than the nut thread portion; and the abutted portion (37) is formed to face one end side of the axial direction with respect to the reduced diameter portion; and At least one ring (70) disposed in a space radially inward of the nut thread portion of the nut, having a higher modulus of elasticity than the tube, and abutting the nut to the above-mentioned nut a joint having the following elastic modulus: the body, the nut, and the ring for the tube In the state of the connection, when the ring is in the elastic region, the ring is pressed from the radially outer side toward the radially inner side by the stress of the ring, and is located at the outer peripheral portion of the ring. A radial gap is disposed between the inner peripheral portions of the nuts on the radially outer side of the ring, and the expanded ring is formed by the radially inner side surface of the nut when the ring is in a state beyond the elastic region The inner side of the radial direction is pressed toward the inner side in the radial direction, and the elastic modulus of the nut is 400 MPa or more and 800 MPa or less. The elastic modulus of the ring is 1000 MPa or more and 2500 MPa or less, and the ring is configured to extend beyond the elastic region at a stage before the ring abuts on the radially inner side surface of the nut. The joint of claim 1, wherein the shape of the cross section of the ring in the normal direction of the circumferential direction is a shape of a rectangular shape, at least a radially inner side, and a portion of the main body side of the axial direction is chamfered or has a circle a shape of a corner, wherein a portion of the radially inner side of the ring and the body side of the axial direction passing through the chamfered shape or the portion having the rounded shape is 0.3% or more of a width of a radial direction of the ring and 40% or less, and is a portion of 1% or more and 40% or less of the width of the axial direction of the ring. The joint of claim 2, wherein a portion of the radially inner side of the ring and the body side of the axial direction passing through the chamfered shape or the portion having the rounded shape is a radial width of the ring A portion of 3% or more and 29% or less is a portion of 2% or more and 25% or less of the width of the ring in the axial direction. The joint of claim 1, wherein in the state in which the body, the nut and the ring are connected to the tube, in a state in which the ring is in an elastic region, in the inner peripheral portion of the nut When the inner diameter of the portion located radially outward is the largest portion with respect to the outermost portion of the ring, and the outer diameter of the portion where the outer diameter of the ring is the largest is set to Y, the nut is And the length of the portion corresponding to the above X and the above Y in a state in which the ring is not connected without any force, and the value of (XY)/Y is 0.003 or more and 0.020 or less. The joint of claim 1, wherein in the state in which the body, the nut and the ring are connected to the tube, in a state in which the ring is located in the elastic region, in the inner peripheral portion of the nut The inner diameter of the portion located radially outward with respect to the outermost portion of the ring is X, the outer diameter of the portion where the outer diameter of the ring is the largest is Y, and the thickness of the tube is set to In the case of Z, the value of (XY)/Z is the length of the portion corresponding to X, Y, and Z in a state where the nut, the ring, and the tube are not connected to each other without any force. 0.04 or more and 0.30 or less. The joint of claim 1, wherein the tube comprises a resin composition containing at least one selected from the group consisting of PFA, FEP, and PTFE, the nut comprising the member selected from the group consisting of PFA, PCTFE, PVDF, ETFE, and PPS. A resin composition of at least one of the group consisting of the resin composition containing at least one selected from the group consisting of PCTFE, PVDF, ETFE, and PPS. The joint of claim 1, wherein the ring is opaque, and the nut is transparent or translucent. A joint assembly (150) comprising: the tube (90); and the joint (100) according to any one of claims 1 to 7, wherein the tube comprises a resin having chemical resistance, and the bending radius is 0.3 m or more and 3.0 m or less.