JP2783784B2 - Manufacturing method of connection fittings for pressure-resistant hoses - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a fitting for a pressure-resistant hose for connecting a pressure-resistant hose to which a fluid is transferred to equipment.

[0002]

2. Description of the Related Art FIG. 9 shows a conventional fitting 1 for a pressure-resistant hose.
FIG. The pressure-resistant hose connection fitting 1 is used, for example, when connecting a pressure-resistant hose to a device such as an oil supply device. For example, since a pressure of up to about 70 kgf / cm ² acts on the pressure-resistant hose made of synthetic rubber due to the fluid to be transferred, the pressure-resistant hose fitting 1 can easily be formed even when such a large pressure is applied. As shown in FIG. 9, an inner tube 15 and an outer tube 16 are provided so as not to be pulled out, and a pressure-resistant hose is fitted between the inner tube 15 and the outer tube 16 so that the inner tube 15 and the outer tube 16 Hold the pressure hose. This prevents the pressure hose from being easily pulled out.

[0003] A threaded portion 17 is formed at the base end of the pressure-resistant hose fitting 1, and the threaded portion 17 is screwed and fixed to a device to be connected.

[0004] It is inevitable that the fluid transferred from between the inner cylinder 15 and the outer cylinder 16 of such a pressure-resistant hose fitting 1 is leaked. Therefore, when the connection fitting for a pressure-resistant hose is to be integrally formed by cutting, for example, in order to prevent leakage, the space between the inner tube 15 and the outer tube 16 is very narrow. Very difficult. Therefore, as shown in FIG. 9, the connection fitting 1 for a pressure-resistant hose is formed by separately forming the inner tube 15 and the outer tube 16 and inserting and fixing the inner tube 15 to the outer tube 16.

The inner cylinder 15 has a large-diameter portion 19 having a larger diameter than the hose connection portion 18 formed coaxially at one axial end of a substantially cylindrical hose connection portion 18 into which a pressure-resistant hose is fitted. The outer cylinder 16 has an inner diameter slightly larger than the outer diameter of the large diameter portion 19 of the inner cylinder at one axial end of a substantially cylindrical hose fitting portion 20 into which the pressure-resistant hose is fitted. A tube fitting portion 21 is formed. The outer cylinder 16 has a screw portion 17. The inner cylinder fitting portion 21 of the outer cylinder 16 has the inner cylinder 15
After the large-diameter portion 19 of the inner cylinder 15 is fitted, the connection between the large-diameter portion 19 of the inner cylinder 15 and the inner cylinder fitting portion 21 of the outer cylinder 16 is fixed by welding, for example, with a silver braze 22 over the entire circumferential direction. Is done. In this way, the inner cylinder 15 and the outer cylinder 16 are securely fixed by welding, so that the transfer fluid is prevented from leaking from between the inner cylinder 15 and the outer cylinder 16.

[0006]

The annular space between the inner cylinder 15 and the outer cylinder 16 is 3-6 so as to hold the pressure-resistant hose.
When the inner cylinder 15 and the outer cylinder 16 are fixed to each other by welding, they must be welded from such a narrow annular space. Further, when welding, welding must be performed while heating the outer cylinder so that heat does not escape to the outside. Therefore, there is a problem that welding work is extremely difficult and productivity is poor.

When the inner tube 15 and the outer tube 16 are fixed by welding, scale is generated by heat at the time of welding, and the aesthetic appearance is deteriorated. Therefore, the scale must be washed and removed with an acid. In addition, there is a problem that productivity is further deteriorated. Further, in the case of fixing by welding, it is difficult to weld different metals having different linear expansion coefficients or stainless steel, so that there is a problem that the material of the inner cylinder 15 and the outer cylinder 16 is limited.

As described above, instead of the method of manufacturing the pressure-resistant hose connection fitting 1 for fixing the inner tube 15 and the outer tube 16 by welding, a connection tube for the pressure-resistant hose fixing the inner tube 15 and the outer tube 16 with screws. There are 25 manufacturing methods.

FIG. 10 is a sectional view showing a connection fitting 25 for a pressure-resistant hose. The connection fitting 25 for the pressure-resistant hose is shown in FIG.
The same components as those of the pressure-resistant hose connection fitting 1 shown in FIG. An outer screw 26 is formed on the outer periphery of the large diameter portion 19 of the inner cylinder 15, and an inner screw 27 that is screwed to the outer screw 26 is formed on the inner circumference of the inner cylinder fitting portion 21 of the outer cylinder 16. The inner cylinder 15 and the outer cylinder 16 are externally threaded 2
6 between the inner screw 27 and the outer screw 26.
The inner cylinder 15 is fixed to the outer cylinder 16 by screwing the inner screw 27 to the outer cylinder 16. Thus, the inner cylinder 15 and the outer cylinder 1
6 is fixed by a screw and an adhesive, but fixing with such a screw causes a problem that reliability is lower in liquid tightness than fixing by welding.

[0010] Accordingly, an object of the present invention is to provide a method of manufacturing a pressure-resistant hose fitting that can easily and surely connect the inner cylinder and the outer cylinder and improve productivity. .

[0011]

According to the present invention, a large-diameter portion having a larger diameter than the hose connection portion is formed coaxially at one axial end of a substantially cylindrical hose connection portion into which a pressure-resistant hose is fitted outside. An outer cylinder in which an inner cylinder fitting portion into which the large-diameter portion of the inner cylinder is fitted is formed at one axial end of a substantially cylindrical hose fitting portion into which the pressure-resistant hose is fitted inside. Wherein the inner diameter of the inner cylinder fitting portion is formed to be smaller than the outer diameter of the large diameter portion of the inner cylinder, and the inner cylinder has a lower temperature than the outer cylinder. A method for manufacturing a connection fitting for a pressure-resistant hose, characterized by returning the temperature to room temperature after fitting a large-diameter portion of an inner cylinder into an inner cylinder fitting portion of an outer cylinder. According to the present invention, the inner diameter of the inner cylinder fitting portion of the outer cylinder into which the large diameter portion of the inner cylinder fits is formed to have a smaller diameter than the large diameter portion of the inner cylinder. When assembling, the inner cylinder is cooled at a lower temperature than the outer cylinder, that is, the inner cylinder is cooled below room temperature to shrink the large diameter portion of the inner cylinder, or the outer cylinder is heated above room temperature to fit the outer cylinder. After expanding the part, the large-diameter part of the inner cylinder is fitted into the inner-tube fitting part of the outer cylinder, and then returned to room temperature to crimp the large-diameter part of the inner cylinder and the inner-tube fitting part of the outer cylinder. It is fixed securely. The normal temperature is a temperature at which the connection fitting for the pressure-resistant hose is actually used, and thus has a value having a certain width. As described above, the inner cylinder and the outer cylinder are easily and securely fixed, so that productivity is improved. Further, since the inner cylinder and the outer cylinder are press-bonded and fixed, even stainless steel or dissimilar metals, which are difficult to weld, can be reliably fixed. Such a fitting for a pressure-resistant hose is fixed to a device, and a pressure-resistant hose is inserted between an inner tube and an outer tube to sandwich the pressure-resistant hose and connect the device and the pressure-resistant hose.

Further, at the open end of the large diameter portion of the inner cylinder of the present invention,
A ridge protruding radially outward is formed over the entire circumference, and a fitting groove into which the ridge is fitted is formed in the inner cylinder fitting portion of the outer cylinder. According to the present invention,
A protrusion is formed on the large diameter part of the inner cylinder, and a fitting groove is formed on the inner cylinder fitting part of the outer cylinder, so the large diameter part of the inner cylinder is crimped to the inner cylinder fitting part of the outer cylinder When fixed, the protrusion of the inner cylinder fits into the fitting groove of the outer cylinder. Therefore, even if the attached pressure-resistant hose is pulled or the like, and a pulling force acts on the outer cylinder, since the protrusion of the inner cylinder is fitted into the fitting groove of the outer cylinder, the inner cylinder is moved from the outer cylinder. Pulling out is reliably prevented.

Further, at the open end of the large diameter portion of the inner cylinder of the present invention,
A fitting protrusion protruding in the axial direction is formed, and a step portion having a fitting recess in which the fitting protrusion fits is formed in the inner cylinder fitting portion of the outer cylinder. . According to the present invention,
The inner cylinder and the outer cylinder are fitted with the outer peripheral surface of the large-diameter portion of the inner cylinder and the inner cylinder in a state in which the fitting projection of the inner cylinder is fitted in the fitting recess of the step portion of the outer cylinder. The inner cylinder and the outer cylinder are fixed in a state where the inner peripheral surface of the portion, the outer peripheral surface of the fitting convex portion, and the inner peripheral surface of the step portion in which the fitting recess is formed are crimped. Therefore, the inner cylinder and the outer cylinder are 2
Since it is pressure-bonded at a location, the liquid-tightness is improved and the liquid crystal is securely fixed.

Further, the inner cylinder fitting portion of the present invention is formed with a locking portion for locking the large diameter portion of the inner cylinder by deforming the inner cylinder inward after fitting the inner cylinder to the outer cylinder. It is characterized by. According to the present invention, after the large diameter portion of the inner cylinder is fitted to the inner cylinder fitting portion of the outer cylinder, the locking portion formed on the outer cylinder is deformed inward to lock the inner cylinder. Even if a tensile force acts on the inner cylinder, the inner cylinder is prevented from being pulled out of the outer cylinder by the locking portion.

The large-diameter portion of the inner cylinder according to the present invention is characterized in that a recess for a locking portion which is recessed facing the base end of the locking portion is formed. According to the present invention, the inner cylinder is formed with a locking portion recess that is recessed toward the base end of the locking portion formed on the outer cylinder, so when the locking portion is deformed inward, Since the base end of the engaging portion fits into the locking portion recess, no excessive force acts on the locking portion, and the inner cylinder can be reliably prevented from being removed.

[0016]

FIG. 1 is a sectional view showing a pressure-resistant hose connection fitting 30 according to a first embodiment of the present invention, and FIG. 2 is a perspective view showing the pressure-resistant hose connection fitting 30. 3 is an exploded perspective view of the connection fitting 30 for a pressure-resistant hose. In FIG. 3, the outer cylinder 32 is shown in a sectional view. The pressure-resistant hose connection fitting 30 is composed of an inner cylinder 31 and an outer cylinder 32 made of metal such as brass, for example. The inner cylinder 31 has a substantially cylindrical hose connection portion 33 into which the pressure-resistant hose is fitted outside.
A large-diameter portion 34 having a larger diameter than the hose connection portion 33 is formed coaxially at one end in the axial direction. A plurality of annular ridges 39 are formed on the outer peripheral portion of the hose connection portion 33, and the pressure-resistant hose that fits into the hose connection portion 33 is prevented from coming off. One end of the hose connection portion 33 in the axial direction is connected to the connecting portion 3 which expands.
The large-diameter portion 34 is formed continuously with the intermediary of 5.

The outer cylinder 32 has an inner cylinder 3 at one axial end of a substantially cylindrical hose fitting portion into which the pressure-resistant hose is fitted.
An inner cylinder fitting portion 36 having an inner diameter D3 smaller than the outer diameter D2 of the large diameter portion 34 is formed. Hose fitting part 42
A plurality of annular ridges 40 are formed on the inner peripheral portion, and a pressure-resistant hose that fits into the hose fitting portion 42 is prevented from coming off. By inserting a pressure-resistant hose between the inner cylinder 31 and the outer cylinder 32, the pressure-resistant hose is sandwiched between the hose connection part 33 and the hose insertion part 42.
It is stopped by 9, 40.

The inner cylinder fitting portion 36 is a large-diameter portion 34 of the inner cylinder 31.
Has an inner peripheral surface 46 that makes surface contact with the outer peripheral surface 45 of the large-diameter portion 34 when fitted. A step surface is formed between the inner peripheral surface 46 of the inner cylinder fitting portion 36 and the hose fitting portion 42. 44 are formed.
A substantially cylindrical screw portion 37 having a diameter smaller than that of the inner cylinder fitting portion 36 is formed at one end in the axial direction of the inner cylinder fitting portion 36 (below in FIG. 1). Is formed with an external screw 38, and the screw portion 37 is screwed and fixed to a device such as an oil supply device.

The inner peripheral surface 48 at one end in the axial direction of the inner cylinder fitting portion 36 is formed to have a smaller diameter than the inner peripheral surface 46, and the inner peripheral surface 48 and the inner peripheral surface 46 are interposed via the step surface 41. Be connected. When the large diameter portion 34 of the inner cylinder 31 is fitted to the step surface 41 of the inner cylinder fitting portion 36 of the outer cylinder 32, the inner peripheral surface 49 of the large diameter portion 34 and one end of the inner cylinder fitting portion 36 in the axial direction are fitted. The transfer fluid flows smoothly with the inner peripheral surface 48 on the side. The large diameter portion 34 and the connecting portion 35 of the inner cylinder 31 are connected via a step surface 50,
When the large diameter portion 34 is fitted into the inner cylinder fitting portion 36 until it reaches the step surface 41 of the outer cylinder 32, the step surface 50 of the inner cylinder 31
And the step surface 44 of the outer cylinder 32 are flush with each other.

At the outer peripheral portion of the outer cylinder 32, a hooking portion 43 having a substantially hexagonal outer shape in a section perpendicular to the axis is formed, and a tool such as a spanner can be hooked on the hooking portion 43.

The length L1 of the outer cylinder 32 is selected to be, for example, about 57 mm, and the outer diameter D1 is selected to be, for example, about 35 mm.

When assembling the inner cylinder 31 and the outer cylinder 32,
In a state where the inner cylinder 31 is cooled and contracted, the inner cylinder 31 is
2, the large-diameter portion 34 of the inner cylinder 31 is fitted into the inner cylinder fitting portion 36 of the outer cylinder 32, and the temperature is returned to room temperature in this state, whereby the inner cylinder 31 expands to its original size. The large diameter part 34 of the inner cylinder 31 and the inner cylinder fitting part 36 of the outer cylinder 32 are crimped, and the inner cylinder 31 and the outer cylinder 32 are securely fixed.

Brass has a linear expansion coefficient α = 1.84 × 10
⁻⁵ (° C. ⁻¹ ), so that the outer diameter D2 of the large diameter portion 34 is 24.
In the case of 00 mm, the outer diameter D2 shrinks by about 0.05 to 0.15 mm by cooling the large diameter portion 34 of the inner cylinder 31 to, for example, about -200 ° C. with liquefied nitrogen. Therefore, the outer diameter D3 of the inner cylinder fitting portion 36 of the outer cylinder 32 is 2
It is selected to be about 3.85 to 23.95 mm, preferably 2
3.90mm is selected.

Instead of cooling and shrinking the inner cylinder 31,
After the outer cylinder 32 is heated to expand the inner cylinder fitting portion 36, the inner cylinder 31 may be fitted and returned to normal temperature to fix the inner cylinder 31 and the outer cylinder 32. In such a case, the scale may be generated by the high temperature and the aesthetic appearance may be deteriorated. Therefore, it is preferable that the inner cylinder 31 is manufactured by cooling.

Since the inner cylinder 31 and the outer cylinder 32 are fixed by crimping, even if the inner cylinder 31 and the outer cylinder 32 are made of dissimilar metals, they can be securely fixed. In the case of a metal having a relatively large coefficient of linear expansion α, such as an aluminum alloy, it is sufficiently contracted by being cooled to about −80 ° C. with dry ice, and thus is easily and inexpensively manufactured using dry ice. can do.

Even if the inner cylinder 31 and the outer cylinder 32 are made of stainless steel, which is difficult to fix by welding, they are fixed by crimping, so that they can be securely fixed. An adhesive is interposed between the large-diameter portion 34 of the inner cylinder 31 and the inner cylinder fitting portion 36 of the outer cylinder 32 so that the inner cylinder 31 and the outer cylinder 32 can be more securely and liquid-tightly fixed. You may. The material of the inner cylinder 31 and the outer cylinder 32 may be copper, cast iron, or the like, and the cooling means may be ethanol, liquefied oxygen, or the like.

FIG. 4 is a sectional view showing a connection fitting 55 for a pressure-resistant hose according to a second embodiment of the present invention. FIG. 1
3 are denoted by the same reference numerals, and description thereof is omitted. At the open end of the large-diameter portion 34 of the inner cylinder 31 of the pressure-resistant hose connection fitting 55, a ridge 5 projecting radially outward from the outer peripheral surface 45 is provided.
6 is formed over the entire circumference in the circumferential direction, and a fitting groove 57 into which the ridge 56 is fitted is formed at an end of the inner peripheral surface 46 of the inner cylinder fitting portion 35 of the outer cylinder 32 on the step surface 41 side. It is formed over the entire circumference. The ridge 56 has a tapered surface that becomes radially outward toward the opening end.

Therefore, after the inner cylinder 31 is cooled and contracted, the large-diameter portion 34 is fitted into the inner cylinder fitting portion 36, and the temperature is returned to room temperature. The large-diameter portion 34 fits into the fitting groove 57 and the inner cylinder fitting portion 36
It is crimped and fixed. Thus, the ridge 5 of the inner cylinder 31
6 is fitted in the fitting groove 57 and the inner cylinder 31 and the outer cylinder 3
2 is fixed, so that even if a tensile force acts on the inner cylinder 31, the ridge 56 is locked in the fitting groove 57, so that the inner cylinder 31 is prevented from easily being pulled out of the outer cylinder 32. Can come off.

FIG. 5 is a sectional view showing a fitting 60 for a pressure-resistant hose according to a third embodiment of the present invention. FIG. 1
3 are denoted by the same reference numerals, and description thereof is omitted. Inner cylinder 31
At the open end of the large-diameter portion 34, a fitting projection 61 projecting in the axial direction from the middle portion in the thickness direction of the large-diameter portion 34 is formed over the entire circumference in the circumferential direction. In the step portion having the step surface 41, a fitting recess 62 in which the fitting protrusion 61 fits is formed from the step surface 41. Therefore, after the inner cylinder 31 is cooled and contracted, the fitting projection 61 is fitted into the fitting recess 62, and the large-diameter portion 34 is connected to the inner cylinder fitting portion 3.
6 and returned to normal temperature, the inner cylinder 31 and the outer cylinder 32 are separated from the outer peripheral surface 45 of the large-diameter portion 34, the inner peripheral surface 46 of the inner cylinder fitting portion 36, and the outer periphery of the fitting projection 61. The surface 63 and the inner peripheral surface 64 of the inner cylinder fitting portion 36 in which the fitting recess 62 is formed are pressed against each other, thereby ensuring the inner cylinder 31 in a liquid-tight manner.
And the outer cylinder 32 are fixed.

FIG. 6 is a sectional view showing a connection fitting 67 for a pressure-resistant hose according to a fourth embodiment of the present invention. FIG. 1
The components corresponding to the pressure-resistant hose connection fitting 30 shown in FIG. Inner cylinder 3
At the open end of the large-diameter portion 34, a fitting projection 68 projecting from the inner periphery of the large-diameter portion 34 in the axial direction is formed over the entire circumference in the circumferential direction. In the step portion where the step surface 41 is formed, a fitting recess 69 into which the fitting convex portion 68 is fitted is formed in the inner peripheral portion of the step portion over the entire circumference in the circumferential direction. The fitting projection 68 has a tapered surface 70 that inclines radially inward toward the tip, and a fitting recess 69.
Is formed on the inner cylinder fitting portion 36, which has a tapered surface 71 with which the tapered surface 70 of the fitting projection 68 contacts. Therefore,
After cooling the inner cylinder 31 and fitting the fitting projection 68 into the fitting recess 69 and fitting the large-diameter portion 34 into the inner cylinder fitting portion 36, the temperature of the large-diameter portion 34 is reduced by returning to room temperature. The outer peripheral surface 45 is crimped to the inner peripheral surface 46 of the inner cylinder fitting portion 36, and the tapered surface 70 of the fitting convex portion 68 is crimped to the tapered surface 71 of the inner cylinder fitting portion 36. And the outer cylinder 32 are securely fixed, and the liquid tightness is improved.

FIG. 7 is a sectional view showing a connection member 75 for a pressure-resistant hose according to a fifth embodiment of the present invention, and FIG. 8 is a partially enlarged sectional view of the connection member 75 for a pressure-resistant hose showing the vicinity of a locking portion 76. It is. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted. Step surface 44 of inner cylinder fitting portion 36 of outer cylinder 32
A plurality of, for example, 2 to 8 locking portions 76 projecting in the axial direction from the step surface 44 are provided at an inner peripheral portion of the inner peripheral portion at intervals in the circumferential direction. The large diameter portion 34 of the inner cylinder 31 has the locking portion 7
A recess 77 for the locking portion which is recessed toward 6 is formed.

After cooling such an inner cylinder 31 and fitting it into the inner cylinder fitting portion 36 of the outer cylinder 32 to return to room temperature and fixing the inner cylinder 31 and the outer cylinder 32, as shown in FIG. Each locking portion 76 is deformed inward, and the locking portion 76 is
Even if the inner tube 31 is fitted with the pulley 7 and a tensile force acts on the inner tube 31, the large-diameter portion 34 of the inner tube 31 is locked by the locking portion 76 and is prevented from being pulled out.

Since the locking portion recess 77 is formed so as to be recessed facing the base end of the locking portion 76, the locking portion 76 is bent inward and then driven into the locking portion 76. Is deformed, the particularly proximal end of the locking portion 76 fits into the locking fitting recess 77, so that no excessive force acts on the locking portion 76 and the locking portion 76 ensures The inner cylinder 31 can be prevented from coming off.

Instead of providing a plurality of such locking portions 76 and the recesses 77 for the locking portion, the locking portions 76 and the recesses 77 for the locking portion are formed by the step surface 44 of the outer cylinder 32 and the inner cylinder 3, respectively.
The second step surface 50 may be formed over the entire circumference in the circumferential direction, and such a locking portion may be deformed inward to lock the large-diameter portion 34 of the inner cylinder 31. As described above, the locking of the inner cylinder 31 by the locking portion extending over the entire circumference in the circumferential direction ensures that the inner cylinder 31 is securely prevented from being removed.

[0035]

As described above, according to the present invention, the large diameter portion of the inner cylinder is fitted to the inner cylinder fitting portion of the outer cylinder at a lower temperature than the outer cylinder at the inner cylinder fitting portion of the outer cylinder. The inner tube and the outer tube are crimped and securely fixed by fitting into the portion and returning to room temperature.
Therefore, the inner cylinder and the outer cylinder can be easily and reliably fixed, and the productivity is improved. Further, since the inner cylinder and the outer cylinder are press-bonded and fixed, even if the material is difficult to fix by welding, it can be surely fixed.

Further, since the inner cylinder is formed with a ridge and the outer cylinder is formed with a fitting groove into which the ridge is fitted, the large-diameter portion of the inner cylinder is fitted in the inner cylinder fitting portion of the outer cylinder. When fitted, the protrusion of the inner cylinder fits into the fitting groove of the outer cylinder, whereby the inner cylinder can be easily pulled out of the outer cylinder even if a tensile force acts on the inner cylinder. Is prevented.

According to the present invention, since the fitting projection is formed on the large diameter portion of the inner cylinder and the fitting recess is formed on the step of the outer cylinder, the fitting recess is formed. By fixing the inner cylinder and the outer cylinder by fitting the convex portions, the outer peripheral surface of the large-diameter portion and the outer peripheral surface of the fitting convex portion are respectively crimped to the inner cylinder fitting portion of the outer cylinder,
Thereby, the inner cylinder and the outer cylinder are securely and liquid-tightly fixed.

Further, according to the present invention, a locking portion is formed on the outer cylinder, and the inner cylinder is locked by the locking portion. Therefore, even if a tensile force acts on the inner cylinder, the inner cylinder can be easily formed. Pulling out of the outer cylinder is prevented.

According to the present invention, since the recess for the locking portion is formed in the inner cylinder facing the base end of the locking portion, the locking portion is deformed inward when the locking portion is deformed inward. An excessive force does not act on the portion, and the inner cylinder can be reliably prevented from coming off.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a connection fitting for a pressure-resistant hose 30 according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a connection fitting 30 for a pressure-resistant hose.

FIG. 3 is an exploded perspective view of a pressure-resistant hose connection fitting 30.

FIG. 4 is a cross-sectional view showing a connection fitting 55 for a pressure-resistant hose according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a connection fitting for a pressure-resistant hose 60 according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a connection fitting 67 for a pressure-resistant hose according to a fourth embodiment of the present invention.

FIG. 7 is a sectional view showing a connection fitting 75 for a pressure-resistant hose according to a fifth embodiment of the present invention.

FIG. 8 is a connection fitting 7 for a pressure-resistant hose showing the vicinity of a locking portion 76;
5 is a partially enlarged cross-sectional view of FIG.

FIG. 9 is a sectional view showing a conventional fitting 1 for a pressure-resistant hose.

FIG. 10 is a cross-sectional view showing a conventional connection fitting 25 for a pressure-resistant hose.

[Explanation of symbols]

 30, 55, 60, 67, 75 Connection fitting for pressure-resistant hose 31 Inner cylinder 32 Outer cylinder 33 Hose connection part 34 Large diameter part 36 Inner cylinder fitting part 37 Screwing part 41, 44, 50 Step surface 42 Hose fitting part 45 , 63 Outer peripheral surface 46, 48, 49 Inner peripheral surface 56 Ridge 57 Fitting groove 68 Fitting projection 69 Fitting recess 76 Locking portion 77 Locking portion recess

Claims (5)

(57) [Claims] An inner cylinder in which a large-diameter portion larger in diameter than the hose connection portion is formed coaxially at one axial end of a substantially cylindrical hose connection portion into which the pressure-resistant hose is fitted outside, and a pressure-resistant hose. A connection fitting for a pressure-resistant hose, comprising: an outer cylinder in which an inner cylinder fitting portion in which the large-diameter portion of the inner cylinder is fitted is formed at one end in the axial direction of a substantially cylindrical hose fitting portion into which is fitted inside. In the manufacturing method, the inner diameter of the inner cylinder fitting portion is formed to be smaller than the outer diameter of the large diameter portion of the inner cylinder, and the large diameter portion of the inner cylinder is removed at a lower temperature than the outer cylinder. A method for manufacturing a fitting for a pressure-resistant hose, wherein the fitting is returned to room temperature after being fitted into a fitting portion of the barrel. 2. A radially outwardly projecting ridge is formed at the open end of the large diameter portion of the inner cylinder over the entire circumference in the circumferential direction, and the ridge is fitted to the inner cylinder fitting portion of the outer cylinder. The method for manufacturing a connection fitting for a pressure-resistant hose according to claim 1, wherein a fitting groove that fits in is formed. 3. A fitting projection protruding in the axial direction is formed at the opening end of the large diameter portion of the inner cylinder, and the fitting projection is fitted into the inner cylinder fitting portion of the outer cylinder. 3. The method according to claim 1, wherein a step having a fitting recess is formed. 4. The inner cylinder fitting portion is formed with a locking portion for locking the large diameter portion of the inner cylinder by deforming the inner cylinder inward after fitting the inner cylinder to the outer cylinder. The method for manufacturing a connection fitting for a pressure-resistant hose according to any one of claims 1 to 3. 5. The connection for a pressure-resistant hose according to claim 4, wherein a recess for a locking portion is formed in the large-diameter portion of the inner cylinder so as to face the base end of the locking portion. Metal fitting manufacturing method.