JP7401733B2 - fittings - Google Patents

Description

The present invention relates to a joint fitting.

2. Description of the Related Art Conventionally, a hose fitting that is attached to an end of a hose has been provided as a fitting to connect the hose to a device or the like (see Patent Document 1).
The hose fitting has a nipple and a socket that are coupled to each other, and the nipple and the socket are coaxial and have a nipple-side cylindrical part that is open at one end in the axial direction, and a radial direction of the nipple-side cylindrical part. It has a socket side cylindrical part located on the outside.
The hose has an annular space in which the end of the hose is inserted between the outer circumferential surface of the nipple-side cylindrical portion and the inner circumferential surface of the socket-side cylindrical portion.
To attach the hose fitting to the end of the hose, insert the end of the hose into the annular space, and then swage the cylindrical part on the socket side with the crimping device, so that the cylindrical part on the socket side and the end of the hose This is done by integrally attaching the nipple side cylindrical part and the nipple side cylindrical part.

Japanese Patent Application Publication No. 2014-181789

By the way, with the above-mentioned hose fittings, when connecting a cylindrical pipe part to the end of the nipple opposite to the end to which the hose is attached, the pipe part with the same inner diameter as the nipple is connected. Therefore, there was a problem that pressure loss increased due to the continuous inner diameter having relatively small dimensions.
For this reason, pressure loss can be reduced by joining a pipe portion having an inner diameter larger than the inner diameter of the nipple to the end of the nipple, but a step is formed in the inner diameter of the end of the nipple.
In addition, when the nipple and the pipe are joined by friction welding, curl-shaped burrs are formed in an annular shape on the outer and inner peripheral surfaces of the joint surfaces, but the burrs formed inside are cut off because they cause pressure loss. Remove.
However, when removing internal burrs, some burrs may remain, and if these remaining burrs are hidden in the step formed on the inner diameter of the nipple, the detection of burrs will decrease, so the remaining burrs may remain. The burrs may be overlooked, resulting in pressure loss due to the burrs.
The present invention has been made in view of the above circumstances, and provides a joint fitting that reduces pressure loss, ensures detectability of burrs formed inside, and suppresses the occurrence of pressure loss due to burrs. With the goal.

In order to achieve the above-mentioned object, the present invention provides a joint fitting configured by friction welding one end of a first pipe section and an end of a second pipe section, wherein the inner diameter of the second pipe section D2 is formed to have a larger size than the inner diameter D1 of the first pipe part, and the inner diameter of the one end of the first pipe part is formed as a large inner diameter part equal to the inner diameter D2 of the second pipe part, and A portion from the inner diameter portion toward the other end of the first pipe portion is formed with an inclined surface portion whose inner diameter gradually decreases and is connected to the inner peripheral surface of the inner diameter D1 of the first pipe portion, and from the other end portion. If the distance to the sloped surface part is L, and the angle formed by a pair of sloped surfaces located on the diameter of the conical surface formed by the sloped surface part is θ, then tan(θ/2)<D1/L is satisfied. It is characterized by
Further, the present invention is characterized in that the angle θ is greater than 0° and less than 40°.
Further, the present invention is characterized in that the first pipe section is formed as a nipple whose other end side is connected to an end of a hose.
Further, the present invention is characterized in that an end of the second pipe section opposite to the end to which the friction welding is performed is provided with a base for removably coupling the pipe section main body to a device. do.

According to the present invention, the inner diameter D2 of the second pipe section is larger than the inner diameter D1 of the first pipe section, and the inner diameter of one end of the first pipe section is made equal to the inner diameter D2 of the second pipe section. The inner diameter part is formed by an inclined surface part whose inner diameter gradually decreases from the large inner diameter part toward the other end of the first pipe part, and which is connected to the inner circumferential surface of the inner diameter D1 of the first pipe part. If the distance from the end of the slope to the slope is L, and the angle between the pair of slopes located on the diameter of the conical surface formed by the slope is θ, then tan(θ/2)<D1/L Therefore, by making the inner diameter D2 of the second pipe section larger than the inner diameter D1 of the first pipe section, we aim to reduce pressure loss, and ensure the detectability of burrs formed inside to prevent burrs from forming. This is advantageous in suppressing the occurrence of pressure loss.
In addition, by providing an inclined surface section from the large inner diameter section of the first pipe section and connecting it to the inner circumferential surface of the inner diameter D1, deburring performance is improved and it is advantageous in improving the cleanliness of the inner circumferential surface. .
Further, according to the present invention, the angle θ is set to be greater than 0° and less than 40°, which is advantageous in suppressing an increase in pressure loss.

It is a half sectional view of a hose joint fitting. It is a half sectional view of a hose joint fitting. FIG. 3 is a half sectional view of a hose joint fitting with burrs. FIG. 3 is a sectional view of a hose joint fitting according to the present embodiment. (A) is a cross-sectional view of a nipple according to the present embodiment, and (B) is a cross-sectional view of a nipple for comparison. It is a graph showing the relationship between the angle θ of a pipe and the loss coefficient ε. This is an explanation of an experimental example. FIG. 3 is an explanatory diagram showing a procedure for cutting and removing burrs.

Hereinafter, an example in which a joint fitting according to an embodiment of the present invention is applied to a hose joint fitting will be described with reference to the drawings.
First, the hose joint fitting will be explained with reference to FIG.
The hose joint fitting 10 is connected to the end of a hose, and is used to appropriately supply the fluid flowing through the hose to a device or discharge it from the device as appropriate.
As shown in FIG. 1, the hose joint fitting 10 is made of metal and includes a nipple 12, a socket 14, a pipe portion 16, and a nut portion 18.

The nipple 12 (first pipe section) is constructed by coaxially arranging a base section 20, a collar section 22, a coupling groove 24, and a nipple-side cylindrical section 26.
The base portion 20 is a portion to be joined to the pipe portion 16 and has a cylindrical shape, and an end portion is formed as a joint surface J.
The collar portion 22 is provided near the end of the base portion 16 and has an outer diameter larger than that of the base portion 20 .
The coupling groove 24 is a location where one axial end 14A of the socket 14 is coupled.
A collar portion 28 is provided adjacent to the coupling groove 24 .
One of the end faces on both sides of the flange 28 is formed by the side surface of the coupling groove 24, and the nipple side cylindrical part 26 protrudes from the other end face of the flange 28.
The nipple-side cylindrical portion 26 is a portion inserted into the inner peripheral surface of the hose.
On the outer circumferential surface of the nipple-side cylindrical portion 26, a plurality of locking uneven portions 2602 extending in the circumferential direction are formed at intervals in the axial direction.

The socket 14 is disposed such that one axial end 14A thereof is crimped and coupled to the coupling groove 24.
The socket 14 has a socket-side cylindrical portion 30 that extends in a cylindrical shape at a location radially outward of the nipple-side cylindrical portion 26 and continuous with the portion crimped into the coupling groove 24 .
A plurality of locking convex portions 3002 extending in the circumferential direction are formed on the inner peripheral surface of the socket-side cylindrical portion 30 at intervals in the axial direction.

An annular space S into which the end of the hose is inserted is formed between the outer peripheral surface of the nipple-side cylindrical portion 26 and the inner peripheral surface of the socket-side cylindrical portion 30.
The annular space S has an opening at one end in the axial direction of the nipple side cylindrical part 26 and the socket side cylindrical part 30, and at the other end in the longitudinal direction, one end 14A of the socket 14 is connected to the coupling groove 24. Due to this, it is blocked.
Note that there are many types of hose joint fittings 10, and in the present invention, one end 14A of the socket 14 in the axial direction is coupled to the outer circumference of the nipple 12, and the outer circumference of the nipple 12 and the inner circumference of the socket 14 are connected. The present invention is applicable to all hose joint fittings 10 in which an annular space S for inserting a hose is provided in an open manner at the other end of the socket 14 in the axial direction.

When connecting a hose to the hose joint fitting 10, the hose is inserted into the annular space S, and the diameter of the crimping claws of the crimping device arranged on the radially outer side of the socket-side cylindrical part 30 is reduced. By crimping the side cylindrical part 30, the socket side cylindrical part 30, the end of the hose, and the nipple side cylindrical part 26 are connected.

The pipe portion 16 (second pipe portion) is formed into a cylindrical shape with a uniform inner diameter.
The joint surface J of the end of the pipe section 16 and the joint surface J of the nipple 12 (first pipe section) are joined by friction welding.
That is, one end 16A of the pipe portion 16 is joined to one end 12A of the nipple 12, that is, the end 20A of the base 20, by friction welding.
At the other end 16B of the pipe section 16, a nut section 18 is rotatably but not detachably provided.
The nut portion 18 is an example of a cap for removably connecting the pipe main body 10A to equipment or other pipe portions, and a cap without a nut may be connected thereto.

As shown in FIG. 4, in the hose joint fitting 10 of this embodiment, the inner diameter D2 of the pipe portion 16 is larger than the inner diameter D1 of the nipple 12, and the nipple 12 is opened from one end 12A side. A large inner diameter portion 1202, an inclined surface portion 1204, and a main body inner diameter portion 1206 are formed continuously on the same axis.
The large inner diameter portion 1202 is provided at one end 12A of the nipple 12, and has an inner diameter equal to the inner diameter D2 of the pipe portion 16.
The inclined surface portion 1204 is provided at a location from the large inner diameter portion 1202 toward the other end 12B of the nipple portion 12, and its inner diameter gradually decreases from a dimension equal to the inner diameter D2 to a dimension equal to the inner diameter D1. It is formed so as to be connected to the inner circumferential surface of the inner diameter D1.
The main body inner diameter section 1206 is provided from the inclined surface section 1204 to the other end 12B of the nipple section 12, and is formed with a uniform inner diameter D1.

Here, we will explain how the hose joint fitting 10 of the present embodiment increases the inner diameter of the pipe portion 16 without changing the inner diameter of the nipple 12 and forms a taper (sloped surface portion 1204) in the nipple 12. The angle of the taper (the angle of the inclined surface portion 1204) will be explained below.
As shown in FIG. 1, the hose joint fitting 10 is generally formed so that the inner diameter of the pipe portion 16 is equal to the inner diameter of the nipple 12.
It is known that the pressure loss when fluid flows inside the hose fitting 10 decreases as the inner diameter increases, but since the inner diameter of the hose is formed based on JIS (Japanese Industrial Standards) standards, The inner and outer diameter dimensions of the nipple portion 12 are also restricted according to the inner diameter of the hose.
Therefore, as shown in FIG. 2, the pressure loss is reduced by increasing the inner diameter of the pipe portion 16 without changing the inner diameter of the nipple-side cylindrical portion 26 of the nipple 12.
In addition, the hose joint fitting 10 shown in FIG. 2 and subsequent figures is a diagram in which the socket 14 is omitted.

In the hose joint fitting 10 shown in FIG. 2, the inner diameter D2 of the pipe portion 16 is larger than the inner diameter D1 of the nipple 12 (D1<D2).
As a result, a step X is formed on the inner diameter of one end 12A of the nipple 12 that joins the pipe portion 16, and this step X also causes pressure loss, but the pressure loss due to the increase in the inner diameter D2 of the pipe portion 16 Due to the reduction in loss, the pressure loss of the hose joint fitting 10 as a whole is reduced.
However, this step X causes a different problem.

Specifically, when the nipple 12 and the pipe portion 16 are joined by friction welding, a curl-shaped burr B (see FIG. 8(B)) is formed in an annular shape on the outer and inner peripheral surfaces of the joint surface J. However, burrs B on the outer circumference may get caught on other parts or cause injury due to contact, and burrs B on the inside may cause pressure loss, so remove the burrs B on the outer and inner circumferential surfaces. .
However, when cutting and removing the internal curl-shaped burr B, the burr B may remain, and as shown in FIG. If the burr B moves close to X and is hidden by the step X, the remaining burr B may be missed and cannot be removed.
Therefore, in this embodiment, as shown in FIG. 4, the inner diameter of the pipe portion 16 is increased without changing the inner diameter of the nipple 12, and the nipple 12 is tapered to eliminate the step X in the inner diameter of the nipple 12. is forming.
Note that burrs inside the nipple 12 are generally detected from the opening on the nipple 12 side, which is closer than the nut part 18 side.

Next, the angle of the taper, that is, the angle of the inclined surface portion 1204 will be explained.
When detecting burrs remaining on the large inner diameter section 1202 and the inclined surface section 1204, the angle of inclination of the inclined surface section 1204 is adjusted so that the inner peripheral surfaces of the large inner diameter section 1202 and the inclined surface section 1204 can be visually recognized from the opening on the nipple 12 side. form.
That is, as shown in V1 of FIG. The inclined surface portion 1204 and the large inner diameter portion 1202 are visible from the opening, and burrs formed inside the nipple 12 can be detected.
On the other hand, as shown at V2 in FIG. 5(B), the angle θ is set so that the extension line of the inner circumferential surface of the inclined surface portion 1204 collides with the inner circumferential surface of the nipple-side cylindrical body 26 without reaching the opening of the nipple 12. If this is set, the inclined surface portion 1204 and the large inner diameter portion 1202 will not be visible from the opening.

Therefore, the distance in the axial direction of the main body inner diameter section 1206, which is the distance from the other end 12B of the nipple 12 to the inclined surface section 1204, is L, and a pair of When the angle formed by the inclined surface is θ, the inclined angle of the inclined surface portion 1204 is formed so as to satisfy the following equation (1).
tan(θ/2)<D1/L...(1)

Furthermore, the hose joint fitting 10 of this embodiment reduces pressure loss by increasing the inner diameter of the pipe portion 16 without changing the inner diameter of the nipple-side cylindrical portion 26 of the nipple 12. It is necessary to determine the range of the angle θ so that the pressure loss when a taper is formed by the inclined portion 1204 does not increase more than the pressure loss when a step X is formed on the inner diameter of the nipple 12 (FIG. 2).

FIG. 6 is a graph showing the relationship between the angle θ and the loss coefficient ε when the cross-sectional area of the pipe is expanded.
Graph G1 shows the relationship between angle θ and loss coefficient ε when a pipe with inner diameter D1 is expanded to 1.5 times the inner diameter D2, and the pipe with inner diameter D1 is expanded to 3 times the inner diameter D2. Graph G2 shows the relationship between the angle θ and the loss coefficient ε in this case.
The loss head (h) can be expressed by the following equation (2).
h=ε(q1-q2) ² /2g...(2)
ε: Loss coefficient q1: Average flow velocity at pipe inner diameter D1 q2: Average flow velocity at pipe inner diameter D2 g: Gravitational acceleration

In FIG. 6, the angle θ=0° is the case where the pipe is not expanded, and is the case where the inner diameter is uniform as shown in FIG.
Further, the angle θ=180° is the case when the pipe is expanded radially outward, and the step X is formed on the inner diameter of the nipple 12 as shown in FIG. 2, and the loss is It can be seen that the coefficient ε≒1.
Therefore, the inventor conducted an experiment to set the angle θ such that the loss coefficient ε<1, and an experimental example is shown in FIG.

In the experimental example shown in FIG. 7, the length in the axial direction of the nipple 12 is 71.0 mm, the length (distance L) in the axial direction of the inner diameter part 1206 of the nipple 12 is 52.0 mm, and the inner diameter part of the main body of the nipple 12 is 52.0 mm. The inner diameter D1 of the nipple 1206 was 15.0 mm, and the inner diameter D2 of the large inner diameter portion 1202 of the nipple 12 and the pipe portion 16 was 19.4 mm.
In Experimental Examples 1 to 7 when the angle θ is 40°, 35°, 30°, 25°, 20°, 15°, and 10°, the loss coefficient ε is less than 1, and the pressure loss decreases depending on the inner diameter of the nipple 12. The pressure loss is lower than the pressure loss when the step X is formed (FIG. 2).
On the other hand, in Comparative Examples 1 and 2 where the angle θ is 45° and 50°, that is, when the angle θ is larger than 40°, the loss coefficient ε is 1 or more, and the pressure loss is This increases the pressure loss compared to the case where the pressure drop is formed (FIG. 2).
From the above, the angle θ may be greater than 0° and less than or equal to 40°.
Note that the angle θ is preferably 30° or more and 40° or less, but is adjusted as appropriate depending on the length of the nipple 12 in the axial direction.

Next, with reference to FIG. 8, a procedure from joining the nipple 12 and the pipe portion 16 by friction welding to cutting off the burr B will be described.
First, when one end 12A of the nipple 12 and one end 16A of the pipe part 16 are joined by friction welding (FIG. 8(A)), a curled shape is formed on the outer and inner peripheral surfaces of the joint surface J. The burr B is formed in an annular shape (FIG. 8(B)).
The burr B formed on the outer circumferential surface is removed by a deburring tool 40, and the burr B formed on the inner circumferential surface is removed by drilling with a drill 42. Cutting oil flows inside from the portion 16 toward the nipple 12 (FIG. 8(C)).
Since the burr B formed on the inner peripheral surface cannot be removed by drilling alone, an inner diameter deburring tool 44 is inserted to remove the burr B, and the inner diameter is finished (FIG. 8(D)).
In addition to drilling, the burrs formed on the inner circumferential surface may not be removed even if finishing treatment is performed, and the smaller annular burrs are pressed against the inclined surface portion 1204 by the cutting oil (Fig. 8 (E)). ).
The nipple of the hose joint fitting 30 of this embodiment satisfies the above-mentioned formula (1) and has an inclined surface portion 1204 formed at an angle θ greater than 0° and less than 40°, and has an inclined surface portion 1204 formed from the opening on the nipple 12 side. Since the inner peripheral surface can be visually recognized, a deburring pipe 46 is inserted to remove the burr remaining on the inner diameter of the pipe (FIG. 8(F)).

As described above, in the hose joint fitting 10 of the present embodiment, the inner diameter D2 of the pipe portion 16 is larger than the inner diameter D1 of the nipple 12, and the inner diameter of the one end 12A of the nipple 12 is set to the inner diameter of the pipe portion 16. It is formed with a large inner diameter portion 1202 equal to D2, and the inner diameter gradually decreases from the large inner diameter portion 1202 toward the other end 12B of the nipple 12, and is connected to the inner circumferential surface of the main body inner diameter portion 1206 of the inner diameter D1 of the nipple 12. The distance from the other end 112B to the inclined surface 1204 is L, and the angle formed by the pair of inclined surfaces located on the diameter of the conical surface formed by the inclined surface 1204 is θ. In this case, tan(θ/2)<D1/L is satisfied, so the pressure loss is reduced, and the detection of the burr B formed inside is ensured to suppress the occurrence of pressure loss due to the burr B. It is advantageous to do so.
Furthermore, by providing an inclined surface section 1204 from the large inner diameter section 1202 of the nipple 12 and connecting it to the inner circumferential surface of the main body inner diameter section 1206 having the inner diameter D1, deburring performance is improved and the cleaning degree of the inner circumferential surface is improved. It is advantageous above.
In addition, since the angle θ is set to be greater than 0° and less than 40°, the pressure loss of the hose fitting 10 can be lowered than the pressure loss when the step X is formed in the nipple 12, and the pressure loss This is advantageous in suppressing the increase in

10 Hose joint fitting 12 Nipple 14 Socket 16 Pipe portion 18 Nut portion 20 Base portion 22 Collar portion 24 Connection groove 26 Nipple side cylindrical portion 28 Flange portion 30 Socket side cylindrical portion

Claims (3)

One end of the nipple connected to the hose and the end of the pipe are friction welded ,
The nipple includes a cylindrical base having an annular joint surface to be friction-welded, a collar portion having an outer diameter larger than the base, and a coupling groove to which an end of the socket is coupled. , a flange portion facing the collar portion across the coupling groove, and a nipple-side cylindrical portion protruding from the flange portion and inserted into the interior of the hose are arranged in this order,
The outer diameter of the collar portion is larger than the outer diameter of the nipple-side cylindrical portion, so that the radial thickness of the collar portion is greater than the radial thickness of the nipple-side cylindrical portion. formed with dimensions,
An end portion of the socket is coupled to the coupling groove, the hose is inserted into an annular space between the nipple-side cylindrical portion and the socket, and the socket is crimped from radially outside to radially inside. A joint fitting to which the hose is connected ,
The inner diameter D2 of the pipe portion is larger than the inner diameter D1 of the nipple side cylindrical portion ,
The inner diameter of the base portion is formed to be equal to the inner diameter D2 of the pipe portion ,
The inner circumferential surface of the collar portion is formed by an inclined surface portion whose inner diameter gradually decreases from an inner diameter D2 and is connected to the inner circumferential surface of the nipple side cylindrical portion having an inner diameter D1,
When the distance from the other end of the nipple to the inclined surface section is L, and the angle formed by a pair of inclined surfaces located on the diameter of the conical surface formed by the inclined surface section is θ,
Satisfying the following formula (1),
A joint fitting characterized by:
tan(θ/2)<D1/L...(1) The angle θ is greater than 0° and less than 40°,
The joint fitting according to claim 1, characterized in that: A cap for removably coupling the pipe portion to a device is provided at an end of the pipe portion opposite to the end portion to which the friction welding is applied.
The joint fitting according to claim 1 or 2 , characterized in that:

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