JPH11230452A - Hose fittings and brake hoses - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve reliability by reducing defective sealing functions in a sealing portion. SOLUTION: A cylindrical socket portion 1 and a cylindrical nipple portion 2 located inside the socket portion 1 are provided at one end side, and a screw portion 3 into which a joint member is screwed and a nipple portion 2 toward the screw portion 3 are provided. A hose fitting provided on the other end side with a communication hole 5 communicating with the hollow portion 2a and a seal portion 6 formed on the opening edge of the communication hole 5, and a single material is plastically worked. When the shape is formed and when the joint member is screwed into the screw portion and assembled, the tightening torque is 1.0 kgf · m when the tightening starts from the state where the member on the joint member side is in contact with the seal portion. At one time, the joint member rotation angle is more than 72 ° and the tightening torque is 2.0k
The shape and the like of the seal portion are set so that the tightening is completed after the rotation angle of the joint member is 96 ° or more when gf · m.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hose fitting used for an industrial hose and a brake hose using the hose fitting.

[0002]

2. Description of the Related Art A conventional brake hose is constructed by attaching hose fittings 31 to both ends of a brake hose 30, as shown in FIG.

The hose fitting 31 has a cylindrical socket portion 1 and a cylindrical nipple portion 2 located inside the socket portion 1 on one end side, and has a joint member such as a flare nut (shown in the figure). Screw part 3 into which is not screwed
A communication hole 5 communicating the hollow portion 2a of the nipple portion 2 toward the inside of the head 4 where the screw portion 3 is formed, and an opening edge of the communication hole 5 And a disk-shaped flange portion 7 and a groove portion 8 connected to the flange portion 7 at an intermediate portion.

The socket 1 of the hose fitting 31
The end of the hose 30 is inserted into the
Is crushed inward in the radial direction to perform caulking, whereby the hose 30 is sandwiched between the nipple portion 2 and the hose 30 and the hose fitting 31 are integrally fixed.

Next, as shown in FIG. 5, a flare member 32 is inserted into the inner surface of the head 4 of the hose fitting 31 and the flare nut 33 is screwed with the screw portion 33a into the screw portion 3 to be mounted on a vehicle-mounted device. Connected with airtightness and liquid tightness. The flare member 32 is formed by turning a cylindrical portion 32b and a distal end thereof to form a conical tapered folded portion 32a. And tightly sandwiched between them to exert a sealing function.

[0006] As a method of manufacturing such a hose fitting,
There is a method of manufacturing by cutting using a lathe or the like, and a method of manufacturing by plastic working such as cold forging.

[0007] The method of manufacturing a metal fitting for a hose by cutting has the problems that chips are generated, the yield is poor, and the economic efficiency is poor. Therefore, it is hardly used in the production of mass-produced products.

On the other hand, a method of manufacturing a hose fitting by plastic working is excellent in quality, performance, and economic efficiency, and is expected to spread in the future.

[0009]

When the hose fitting is manufactured by plastic working, the outer peripheral edge of the tip is formed with a metal for the purpose of improving the life of the die when the outer peripheral edge of the seal portion 6 is formed. Molding may be performed without being restrained by a mold. Thereby, a curved surface portion R is formed at the outer edge portion of the front end. In this case, as shown in FIG. 6, the curved surface portion has a height RH in the figure, and a fine wrinkle S may be formed.

In addition, when the flare member 32 and the flare nut 33 are assembled in the conventional hose fitting, there is no problem at all in the usual case. If the assembly is performed in a bad state such as the direction of crossing, the folded portion 32a of the flare member 32 may be in a state of one end against the seal portion 6 as shown in FIG. is there. One of the causes of the decrease in the sealing function is that the seal portion is hardened by work hardening due to plastic working and is hardly deformed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a hose fitting capable of reducing a sealing function failure in a sealing portion and improving reliability, and a brake hose using the hose fitting. The purpose is to provide.

[0012]

SUMMARY OF THE INVENTION A hose fitting according to the present invention has a cylindrical socket portion and a cylindrical nipple portion located inside the socket portion at one end, and a screw portion into which a joint member is screwed. A hose having a communication hole communicating with the hollow portion of the nipple portion toward the screw portion, and a seal portion formed at an opening edge of the communication hole on the other end side, and a single material. While the approximate shape is formed by plastic working, when tightening is started from a state where the member on the joint member side is in contact with the seal portion when the joint member is screwed into the screw portion and assembled.
When the tightening torque is 1.0 kgf · m, the rotation angle of the joint member is 72 ° or more, and the tightening torque is 2.0 k
When gf · m, the rotation angle of the joint member is 9
The shape and the like of the seal portion are set so that the tightening is completed after rotating by 6 ° or more.

In addition, a curved chamfer is formed at the outer edge of the tip of the seal, and the radius of curvature of the chamfer is 0.40 m.
m or less.

[0014] It is preferable that the thickness of the seal portion in the vicinity of the front end portion of the front end portion is 0.4 mm or less. A chamfered portion may be provided at an opening edge of the communication hole, and a thickness near a tip of a tip of the seal may be 0.4 mm or less.

The brake hose according to the present invention is characterized in that one of the hose fittings is attached to an end of the hose.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A hose fitting according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1 (a), the hose fitting has a cylindrical socket portion 1 and a cylindrical nipple portion 2 located inside the socket portion 1 at one end thereof. At the other end, a head portion 4 having a screw portion 3 formed on the inner surface into which a joint member (not shown) such as a flare nut is screwed, and an inner side of the head portion 4 having the screw portion 3 formed. A communication hole 5 communicating with the hollow portion 2a of the nipple portion 2 and a truncated seal portion 6 formed at an opening edge of the communication hole 5 are formed. A portion 7 and a groove portion 8 connected to the flange portion 7 are formed. The flare nut is JASO standard F402
This is a part whose shape and dimensions are standardized to -90.

The hose fitting is manufactured, for example, by the following method.

As a first step, a first cylindrical part corresponding to the socket part 1, a cylindrical projection corresponding to the nipple part 2, and a second part having an inner surface on which the screw part 3 is formed in a later step. An intermediate molded product having a cylindrical portion, a cutting portion corresponding to the seal portion 6, and a cylindrical concave portion formed in the cutting portion is manufactured.

This intermediate molded product is obtained by subjecting a cylindrical starting member obtained by cutting a coil-shaped processing material to plastic working with processing equipment such as a multi-stage parts former. Since the degree of processing up to the shape of the intermediate molded product is large, it is better to take as many processing times as possible.

Here, as the material of the working material, since it is formed by plastic working, particularly cold forging, a carbon steel wire for cold heading or its equivalent is selected to prevent embrittlement. I have. For example, JIS standard (JIS G 3539)
SWCH6A is adopted. This is a material obtained by subjecting a material to spheroidizing annealing, surface coating treatment (for example, bonding treatment), drawing, and forming a coil body.
The reduction in the tensile test method for a metal material described in 41 is 75% or more. As a material other than steel, aluminum or its alloy, copper or its alloy, or the like can be adopted.

In the second step, the intermediate molded product is further subjected to plastic working to produce a hose fitting as a final product as shown in FIG.

That is, a mold is arranged on the outer periphery of the above-mentioned projection, and the projection is press-plastically deformed from the rear to form the cylindrical nipple 2. At this time, the hollow portion 2a and the communication hole 5 are formed simultaneously or continuously. Further, a flange 7 and a groove 8 are formed by pressing. The screw portion 3 is formed on the inner surface of the head by rolling. The cutting head corresponding to the seal portion 6 is substantially not machined. Similarly, the first cylindrical portion corresponding to the socket portion 1 is substantially not processed.

Here, if the processing of the outer edge of the tip of the seal portion 6 is not performed in the second step, the first step or the second step is the processing of the outer edge of the seal.
In the process, as shown in FIG. 1B, a curved chamfered portion R is formed at the outer edge of the distal end of the seal portion 6. This chamfer R
Is provided with a curved surface portion corresponding to a radius of curvature to be formed on an inner surface of a mold (not shown) disposed facing the outer edge portion of the front end, and presses a cutting head corresponding to a seal portion on the mold. Thus, the chamfered portion R is formed while being constrained by the curved surface portion of the mold.

FIG. 1B shows the shape of the sealing portion 6 formed by forming the chamfered portion R, and Table 1 shows the dimensional relationship in the drawing. In the table, "Comparative Example" means a product manufactured to determine the effect of the present invention, and "Example"
A certain thing shows what was manufactured by this Embodiment.

[0026]

[Table 1]

Next, the operation of the hose fitting according to the embodiment of the present invention will be described.

In the hose fitting of the present embodiment, as shown in Table 1, the radius of curvature of the chamfered portion R is 0.4 mm, which is smaller than 0.5 mm in the comparative example, and the tip of the tip edge is The thickness C in the vicinity was 0.39 mm, which was 0.4 in the comparative example.
6 and the height RH of the chamfer at the tip edge.
Is 0.13 mm, which is smaller than the comparative example of 0.17 mm.

An air leak test was performed on the hose fitting of the comparative example and the hose fitting of the present embodiment. In the air leak test, the hose fitting was submerged to 4.0 kgf / cm ²
Air pressure was applied to the seal portion in a timely manner to check for air leakage.

In this case, the hose fitting and the flare member 3
2. Flare member 3 when assembling with flare nut 33
5 at a position 7 cm away from the left end of the flare nut 33 in FIG.
(0 kgf · cm) and the case where they did not act were subjected to the test. The result is shown in FIG.

FIG. 2 shows that the time when the flare member 32 hits the seal portion 6 of the hose fitting is 0, and the tightening torque is 1.
At 0, 1.6, 2.0, and 2.4 kgf · m, the flare nut 33 is rotated until it stops, and the rotation angle is represented by the rotation angle. In this case, the flare nut is M10 and has a pitch of 1.0 mm.
If it rotates 0 °, it will be pushed by 1.0 mm.

The number of samples was 10 for each condition, and the minimum value of 10 rotation angles was plotted. As shown in FIG.
The rotation angle tends to increase as the tightening torque increases, and the rotation angle tends to be smaller when a lateral load is applied than when it is not received.

In the above experiment, in the comparative example, when there is a lateral load and the tightening torque is 1.0 kgfm (rotation angle 60
Air leakage occurred in (ii). This was subjected to a water pressure test in which a water pressure of 350 kgf / cm ² was applied for 15 minutes instead of the air pressure, but no leakage occurred. Therefore, it can be seen that there is no problem in practical use, but the air leak test is significant in that it is determined under more severe conditions and is superior to the hydraulic test.

In the hose fitting of the present embodiment, the radius of curvature R of the chamfered portion R formed with the outer edge of the tip, the thickness C near the tip of the edge of the tip, the height of the chamfered portion of the outer edge of the tip. Since the RH is smaller than that of the comparative example, the tip edge portion is easily deformed when tightened, and as shown in FIG. 2, the rotation angle at the time of tightening with the same tightening torque is reduced. It is thought that it is getting bigger.

Table 2 shows the chamfered portion R at the outer edge of the tip of the seal portion 6.
Is calculated from the relationship between the radius of curvature and the required tightening angle. This idea intends to deform the chamfered portion R by the flare member 32. Specifically, the height RH of the chamfered portion R in FIG. 1B is calculated, and the height RH is pressed in. They are trying to do it. For example, when R is 0.4 mm, the height RH is 0.13 mm by geometric calculation.
Becomes Naji is M10 with a pitch of 1.0mm,
Because it advances 1mm at 360 ° C per rotation, if it is 0.13mm,
It will be 48 ° C.

[0036]

[Table 2]

Whether the calculated required tightening angle is appropriate or not is confirmed using the experimental results shown in FIG. In the comparative example having a radius of curvature of 0.50 mm, the required tightening angle was 60 °, and air leakage occurred as described above. When the rotation angle was larger, no air leakage occurred. In this embodiment, the radius of curvature is 0.40.
mm, the required tightening angle (calculated value) from Table 2 is 4
8 ゜. Even when a lateral load was applied, the rotation angle was 75 ° (experimental value), and no air leakage occurred. Therefore, it can be said that the above idea is basically correct.

Actually, a safety factor is expected for the above calculated values in consideration of the play between the screw portion 3 and the screw portion of the flare nut 33, the variation in the surface condition of the seal portion 6, the variation in the fastening operation method, and the like. There is a need.

That is, the tightening torque when the flare nut 33 is tightened to the thread portion 3 of the hose fitting is approximately 1.6 to 2.0 kgfm. Here, it is considered that the safety factor is doubled at 2.0 kgf · m. Therefore, if the radius of curvature of the chamfer at the outer edge of the tip is 0.4, the required tightening angle is 48 ° × 2 = 9.
6 mm or more.

On the other hand, although tightening with a tightening torque of 1.0 kgf · m is not possible in practice, it is considered that a safety factor of 1.5 is secured as a guide in the low torque region.
Similarly, if the radius of curvature of the chamfered portion at the tip edge is 0.4, the required tightening angle is 48 ° × 1.5 = 72 ° or more.

As described above, even when a lateral load is applied when attaching the joint members such as the flare member 32 and the flare nut 33, the chamfered portion at the outer edge of the distal end of the seal portion 6 may be deformed to deteriorate the sealing function. Can be prevented.

Since it is manufactured mainly from a single material by plastic working, there is no room for liquid leakage and high reliability is ensured, unlike the case where separate parts are integrated by soldering. Can be.

The number of parts is one, and parts management becomes easy.
The processing time and the processing steps can be greatly reduced, and since it is manufactured by plastic working, there is basically no generation of chips, the material yield is good, and the product cost can be reduced. In addition, there is no occurrence of liquid leakage, it is possible to prevent a decrease in the sealing function of the sealing portion 6, and it is possible to obtain a highly reliable hose fitting.

FIG. 4 is a sectional view showing a brake hose using a hose fitting obtained by the manufacturing method according to the embodiment of the present invention. The brake hose is constituted by attaching the hose fittings to both ends of the hose 30. The end of the hose 30 is inserted into the socket 1 of the hose fitting, and the socket 1 is crushed radially inward from the outer peripheral side and subjected to caulking, whereby the hose 30 is sandwiched between the nipple 2 and the hose 30. 30 and the metal fitting for the hose are integrally fixed. Here, an example in which two hose fittings are used is shown, but only one hose fitting may be used, and three or more hose fittings may be used, for example.

In this brake hose, a flare member 32 is inserted into the inner surface of the head 4 and a flare nut 33 is screwed into the screw portion 3.
The hose is connected to the vehicle-mounted device by being screwed into the hose. However, since the quality of the hose fitting is improved as described above, a decrease in the sealing function after the screwing is prevented.

It should be noted that a heat treatment may be performed between the first step and the second step in order to reduce or remove work hardening generated in the intermediate molded product when the intermediate molded product is molded. For example, as the heat treatment, there is an annealing in which the intermediate molded product is kept at 740 ° C. for 30 minutes.

FIG. 3 is an enlarged view of a seal portion 16 of a hose fitting according to another embodiment of the present invention. FIG. 1 (b)
And a chamfered portion D is provided at the opening edge of the communication hole 5, and a thickness C near the tip of the tip of the sealing portion 6 is provided.
1 is 0.4 mm or less. In this case, the tip of the tip edge of the seal portion 6 is thinner than the hose fitting of the above-described embodiment, and the tip is easily deformed by tightening the flare nut 33, and the rotation angle at a predetermined tightening torque is reduced. As a result, the sealing function did not easily deteriorate as in the above embodiment.

[0048]

As described above, in the hose fitting of the present invention and the brake hose using the same, it is possible to reduce the sealing function failure at the sealing portion and to improve the reliability.

[Brief description of the drawings]

FIG. 1 is a view showing a hose fitting according to an embodiment of the present invention.

FIG. 2 is a view showing the operation and effect of the hose fitting of FIG. 1;

FIG. 3 is a view showing a main part of a hose fitting according to another embodiment of the present invention.

FIG. 4 is a view showing a brake hose to which the hose fitting of FIG. 1 is attached.

FIG. 5 is a view showing a state where a flare member and a flare nut are assembled to a conventional hose fitting.

FIG. 6 is a view showing a problem in a conventional hose fitting.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Socket part 2 Nipple part 3 Screw part 4 Head 5 Communication hole 6 Seal part C Thickness of the tip part of the tip edge part R Chamfer part of the tip outer edge part D Chamfer part of the opening edge part

Claims (5)

[Claims] A cylindrical socket portion and a cylindrical nipple portion located inside the socket portion are provided at one end side, and a screw portion into which a joint member is screwed and a hollow portion of the nipple portion facing the screw portion are provided. A hose fitting provided on the other end side with a communication hole communicating the portion and a seal portion formed at the opening edge of the communication hole, and a rough shape is formed by plastically processing a single material. Also, when the joint member is screwed into the screw portion and assembled, when tightening is started from a state where the member on the joint member side is in contact with the seal portion, when the tightening torque is 1.0 kgfm When the rotation angle of the joint member is 72 ° or more and the tightening torque is 2.0 kgf · m, the sealing portion is rotated so that the tightening is completed after the rotation angle of the joint member is 96 ° or more. A hose fitting having a shape and the like set. 2. The hose fitting according to claim 1, wherein a curved chamfered portion is formed at an outer edge of a tip of the seal portion, and a radius of curvature of the chamfered portion is 0.40 mm or less. 3. The hose fitting according to claim 1, wherein the thickness of the seal portion in the vicinity of the distal end portion is 0.4 mm or less. 4. A chamfered portion is provided at an opening edge of the communication hole,
0.4m thick near the tip of the tip edge of the seal
The hose fitting according to any one of claims 1 to 3, wherein the length is not more than m. 5. A brake hose, wherein any one of the hose fittings according to claim 1 is attached to an end of the hose.