JPH0721320B2 - Pipe fitting - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint, and more particularly, to a stretchable pipe joint used in a fluid circuit for a fluid such as high-pressure oil or air and for connecting a liquid passage.

(Prior Art and its Problems) As a conventional pipe joint, for example, there is one as shown in FIG. In FIG. 4, reference numeral 1 denotes a pipe joint, and the pipe joint 1
Is a cylinder 2 with one end 2a screwed into a large diameter iron pipe.
And a pipe-shaped piston (outer diameter D ₃ ) 3 connected to a small-diameter iron pipe slidably inserted into the cylinder 2 from the other end 2b of the cylinder 2. Piston 3 is cylinder 2
It is slidably attached to the other end of the disk by a fixing screw 4 via an annular ring 5 containing an O-ring. In such a pipe joint 1, the following formula for pushing the piston 3 by the hydraulic pressure P of the liquid in the piston 3 is applied to the piston. The pushing force F indicated by is applied. This pushing force F is compared with the compressive or bending strength of the iron pipe or the like of the pipe member attached to both ends of the pipe joint 1 when the liquid pressure P is about ² to 10 kgf / cm ² like water pipe. Since it is extremely small, the influence on the piping members can be ignored.

However, when the liquid P is extremely high, such as hydraulic piping, the pushing force F becomes very large, which greatly affects the piping members, and sometimes the iron pipe is broken or the pipe is in use. There is a problem that the length of the joint cannot be adjusted manually.

When hydraulic piping is used, as shown in Figs.
Fastener 7 is fixed to both ends 6a of a plurality of hoses (usually 4 to 7, 4 in this example) (hose diameter 1/2 to 2 ", hose length 4 to 7m), and one end fitting 7 _A Is attached to the equipment using the attachment metal fitting 8 _A , and the other end metal fitting 7 _B is attached to the other equipment so that the hose 6 is bent and attached to the flexible frame 10 by the clamp 9 and can be moved in a single direction. There is a case where hydraulic piping is carried out by so-called cable bear, which is attached by 8 _{B. In} this case, the length of each hose usually varies by 1 to 2%, and each hose 6 has a flexible frame. Ten
Before mounting to the hose, fit the length of each hose 6 to the mounting bracket 8 _A
Or there is a problem that the total length of 8 _B must be adjusted and manufactured.

Also, the hose 6 changes in length when hydraulic pressure is applied,
Generally because the hose is extended, the hose 6 after about one month of the attachment used in the device, it is necessary to manufacture and adjust the total length of the re-mounting bracket 8 _A, 8 _B. If this adjustment is not made, there is a problem that the clamp 9 may be broken or the hose 6 may be damaged by the force due to the extension of the hose 6.

Therefore, the present invention cancels the force in the expansion and contraction direction by the hydraulic pressure in the pipe of the expandable pipe joint used for the fluid circuit, and the length of the pipe joint can be stopped at an arbitrary position, and even when high pressure liquid pressure is applied manually An object of the present invention is to provide a pipe joint whose length can be easily adjusted.

(Means for Solving the Problems) A pipe joint according to the present invention forms a space having a constant interval between an annular cylinder and a cylinder which is attached to one end of the cylinder and projects into the cylinder. A defining member that is slidably inserted between a flange having a tubular protrusion and a cylinder and the protrusion of the flange to define a space between the cylinder and the protrusion of the flange into a pressure chamber and an air chamber. In addition to having a small diameter part through which the pressure liquid flows, the tapered part that expands from the small diameter part toward the protruding part of the flange and the tapered part is continuous through the step part and the protruding part can slide And a tubular piston body having a large diameter portion that is inserted into the piston body, and the piston body receives a pushing force on one side in the axial direction of the piston body by the hydraulic pressure of the pressure liquid introduced into the piston body. The outer diameter A of the piston body The piston body is formed so that the inner diameter B of the large diameter portion of the cylinder body and the inner diameter C of the cylinder are C>A> B, and a communication hole that communicates with the pressure chamber and the piston body is formed in the piston body. The defining member receives the hydraulic pressure in the pressure chamber to receive a pressing force that balances in the opposite direction to the pressing force, and the cylinder has an atmosphere introducing hole for introducing the atmospheric pressure of the outside air into the air chamber. May be done.

(Operation) The pipe joint of the present invention defines a pressure chamber, which is slidably inserted between a tubular cylinder, a flange having a tubular protrusion protruding into the cylinder, and the cylinder and the protrusion of the flange. A piston body having a defining member, wherein the piston body receives a pressing force on one side in the axial direction of the piston body by the hydraulic pressure of the pressure liquid in the piston body, and the defining member of the piston body regulates the hydraulic pressure in the pressure chamber. The piston body receives a pushing force that balances in the opposite direction to the pushing force, so that the piston body is inserted by sliding manually between the cylinder and the protrusion of the flange, regardless of the magnitude of the hydraulic pressure of the pressure fluid. The length of the pipe joint can be adjusted and the pipe joint can be stopped at any position regardless of the hydraulic pressure. Also, on the inner circumference of the piston body, the small diameter part through which the pressure liquid flows, the tapered part that expands from the small diameter part toward the protruding part of the flange, and the tapered part continue to slide through the stepped part. Since the large diameter portion that can be freely inserted is formed and the piston body is formed so that the outer diameter A of the piston body, the inner diameter B of the large diameter portion of the piston body, and the inner diameter C of the cylinder are C>A> B, The hydraulic pressure acts on the large diameter portion of the piston body in one axial direction of the piston body. Therefore, the inner diameter B of the large diameter portion of the piston body is larger than the outer diameter A of the piston body.
And the outer diameter C of the cylinder may be set to an arbitrary value,
It is possible to prevent the partitioning member from projecting outward in the radial direction to a large extent, and it is possible to obtain a small-sized pipe joint.

Further, by setting the inner diameter B of the large diameter portion of the piston body and the inner diameter C of the cylinder to arbitrary values with respect to the outer diameter A of the piston body, a pressing force by which the defining member balances in the opposite direction to the pressing force. Therefore, the degree of freedom in designing the piston body and the cylinder is improved. Further, since the atmosphere introducing hole for introducing the atmospheric pressure of the outside air into the air chamber is formed in the cylinder,
When the piston body slides, air is circulated between the air chamber and the outside air, and the sliding movement of the piston body is not hindered.

(Example) Hereinafter, the Example of this invention is described based on drawing.

1 and 2 are views showing a first embodiment of a pipe joint according to the present invention.

First, the configuration will be described. In Figs. 1 and 2, 11
Is a pipe joint, one end 11a of the pipe joint 11 is attached to the hydraulic intake portion 12a of the hydraulic device 12, and the other end 11b of the pipe joint 11 is one end of a hydraulic hose (diameter 1/2 ″, total length 5 m) 14. Port fitting of part 14a
Installed on 15. The hydraulic hose 14 is, as shown in part in FIG.
As in FIG. 6), it is fixed to the moving table 17 by a hose clamp 18 along the circumference of the moving table 17 which moves in a single direction. One end 14a of the hydraulic hose 14 can be moved to the left side in the drawing together with the moving base 17, and the other end of the hydraulic hose 14 is attached to another fixed hydraulic device (not shown). Four similar hydraulic hoses 14 are arranged in an orderly manner around the movable table 17 to form a so-called cable bear.

In Fig. 1, the pipe joint 11 is a tubular cylinder (inner diameter Cm
m) 20 and a flange 21 attached to one end 20a of the cylinder 20. One end 21a of the flange 21 is a fitting 15
It is fixed by screwing on the tip part 15a of the
1b consists of a tubular protrusion 21b, which is put into the cylinder 20,
An annular space 23 having a constant distance is formed between the inner wall 20b and the inner wall 20b. A tubular piston body (outer diameter Amm) 25 is inserted between the cylinder 20 and the protrusion 21b of the flange 21, and a small-diameter portion 25c through which the pressure liquid flows and a small-diameter portion are formed on the inner peripheral portion of the piston body 25. The stepped portion 25e is formed on the taper portion 25d and the taper portion 25d that expands from the portion 25c toward the protrusion 21b side of the flange 21.
Large-diameter portion 2 in which the protrusion 21b is slidably inserted continuously through
It has 5f (inner diameter Bmm). Also, this piston body 25
The tubular one end portion 25a is screwed into the hydraulic intake portion 12a of the hydraulic device 12, and the other end portion 25b of the piston body 25 is integrally provided with a flange-shaped projecting member 26, which pressurizes the space 23. Chamber 27 and air chamber
Defined as 28. Reference numeral 30 denotes a communication hole, and the communication hole 30 is formed so that the other end portion 25b of the piston body 25 communicates the pressure chamber 27 with the inside of the piston body 25. Reference numeral 31 denotes an atmosphere introduction hole, which is formed in the cylinder 20 and introduces the atmospheric pressure of the outside air into the air chamber 28. 33, 34, 35 are O-rings, 36, 37,
Reference numeral 38 is a backup ring that supports the O-rings 33, 34 and 35, respectively.

The piston body 25 is moved in the axial direction of the piston body 25 by the hydraulic pressure P of the pressure liquid introduced into the piston body 25 in the left direction (arrow L) of the figure to the following formula. Receive pressing force F ₁ shown in. Also, the defining member of the piston body 25
26 receives the hydraulic pressure P of the pressure chamber 27 on the annular surface 26a of the defining member 26 inside the pressure chamber 27, and in the axial direction of the piston body 25 in the right direction (arrow R) in the figure, that is, the pressing force F described above _{In the} opposite direction of ₁ Upon receiving the pushing force F ₂ indicated by, the pushing force F ₂ is balanced with the pushing force F ₁ .

Next, the operation will be described.

The pipe joint 11 of the present invention includes a cylinder 21 and a protrusion 21 of a flange 21.
the piston member 25 is slidably inserted between the b, or pushing force F ₁ of the piston body 25 is extruded to the left in FIG axially by hydraulic pressure P (arrow L direction), axial Since it is in balance with the pushing force F ₂ pushed in the right direction (the direction of arrow R) in the figure, the piston body 25 is irrelevant to the cylinder 20 regardless of the hydraulic pressure P of the pressure liquid in the piston body 25. And protrusion of flange 21
The length of the pipe joint can be adjusted by inserting it between 21b and the body while sliding it by hand with a force smaller than the sliding resistance between them. Further, the piston body 25 can be stopped at any position with respect to the cylinder 20. Therefore, in the hydraulic piping as shown in FIG. 2, even if the lengths of the four hydraulic hoses 14 attached to the moving base 17 vary,
By adjusting the lengths 11 _{A to} 11 _D of the pipe fittings 11 (11 _{A to} 11 _D ) attached to the 14 fittings 15 by hand, respectively, the fittings of various lengths can be adjusted as in the past. It can be fixed to the movable table 17 with an appropriate length without manufacturing. In addition, even if the readjustment is done one month after using the hose, it is not necessary to adjust and manufacture the conventional fittings by adjusting the pipe joint 11 in the same manner as described above, and it is extremely easy to attach and readjust the hydraulic hose 14 and the pipe joint 11. It can be done quickly and the work cost can be greatly reduced. Further, on the inner peripheral portion of the piston body 25, a small diameter portion 25c through which the pressure liquid flows, a tapered portion 25d and a tapered portion that expand from the small diameter portion 25c toward the protrusion 21b side of the flange 21.
An outer diameter A of the piston body 25 is formed on the outer diameter A of the piston body 25 by forming a large diameter portion 25f that is continuous with the step portion 25e in the step 25d and into which the protrusion 21b is slidably inserted.
Since the piston body 25 is formed so that the inner diameter B of the large diameter portion 25c of the piston body 25 and the outer diameter C of the cylinder 20 are C>A> B, the piston body 25 is formed in the large diameter portion 25f of the piston body 25.
It is possible to apply a hydraulic pressure in one axial direction of. Therefore, the inner diameter B of the piston body 25 and the inner diameter C of the cylinder 20 may be set to arbitrary values with respect to the outer diameter A of the piston body 25, and the partition member 26 can be largely projected outward in the radial direction. Can be prevented. Because of this, the cylinder
A small pipe fitting that prevents 20 from becoming large in the radial direction.
You can get 11.

Further, by setting the inner diameter B of the piston body 25 and the inner diameter C of the cylinder 20 to arbitrary values with respect to the outer diameter A of the piston body 25, the pushing force F ₁ and the pushing force F ₂ acting on the piston body 25 are set. Since they can be balanced, the piston body 25 and the cylinder 20
The degree of freedom in design can be improved. Further, the cylinder 20 has an air introduction hole for introducing the atmospheric pressure of the outside air into the air chamber 28.
31 forms an air chamber when the piston body 25 slides.
Air can be circulated between the inside and outside air, and the sliding of the piston body 25 can be prevented from being hindered. Next, a second embodiment of the present invention will be described.

FIG. 3 is a diagram showing a second embodiment of the pipe joint according to the present invention.

In the second embodiment, the flange 21 of the pipe joint 41 of the present invention is used.
This is the case where the side is attached to the device 12 and the tip end portion 42a of the piston body 42 is integrally formed with the inner fitting of the mouth fitting 15 fixed to the tip end portion 14a of the hose 14. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

(Effects) As described above, according to the present invention, the force in the expansion and contraction direction due to the hydraulic pressure in the pipe of the expandable pipe joint used for the fluid circuit is canceled, and the length of the pipe joint can be arbitrarily set, and at the same time, high pressure can be achieved. The length can be easily adjusted manually even when the liquid pressure is increased. Further, by mounting a plurality of hoses to which the pipe joint of the present invention is attached to a so-called cable bear, it is possible to easily and quickly adjust the installation length when installing the hoses and readjust the length after use manually. The work cost can be significantly reduced. Also, on the inner circumference of the piston body, the small diameter part through which the pressure liquid flows, the tapered part that expands from the small diameter part toward the protruding part of the flange, and the tapered part continue to slide through the stepped part. Since the large diameter portion that can be freely inserted is formed and the piston body is formed so that the outer diameter A of the piston body, the inner diameter B of the large diameter portion of the piston body, and the inner diameter C of the cylinder are C>A> B. The hydraulic pressure acting in one axial direction of the piston body acts on the large diameter portion of the piston body. Therefore, the inner diameter B of the large-diameter portion of the piston body and the outer diameter C of the cylinder may be set to arbitrary values with respect to the outer diameter A of the piston body, and the defining member is projected largely outward in the radial direction. Can be prevented, and a small pipe joint can be obtained.

In addition, the inner diameter B of the piston body with respect to the outer diameter A of the piston body
And by setting the inner diameter C of the cylinder to an arbitrary value,
Since the pressing force F ₁ acting on the piston body and the pressing force F ₂ can be balanced, the degree of freedom in designing the piston body and the cylinder can be improved. Further, since the atmosphere introducing hole for introducing the atmospheric pressure of the outside air into the air chamber is formed in the cylinder, the air can be circulated between the air chamber and the outside air when the piston body slides, and the piston body slides. It is possible to prevent the movement from being disturbed.

[Brief description of drawings]

1 and 2 are views showing a first embodiment of a pipe joint according to the present invention, FIG. 1 is a longitudinal sectional view thereof, and FIG. 2 is a partial plan view showing a state of use thereof, FIG. The drawing is a partial sectional view showing a second embodiment of the pipe joint according to the present invention. 4 to 6 are views showing a conventional pipe joint, FIG. 4 is a longitudinal sectional view thereof, and FIGS. 5 and 6 are a plan view and a side view showing a state during use thereof, respectively. 11, 41 …… Pipe fittings, 12 …… Hydraulic equipment, 14 …… Hydraulic hoses, 15 …… Port fittings, 17 …… Transport bases, 18 …… Hose clamps, 20 …… Cylinders, 21 …… Flanges, 23… … Space, 25, 42 …… Piston body 25c …… Small diameter part, 25d …… Tapered part, 25e …… Step part, 25f …… Large diameter part, 26 …… Defining member, 27 …… Pressure chamber, 28… … Air chamber, 30… Communication hole, 31… Atmosphere introduction hole, A… Piston body outer diameter, B… Piston body inner diameter, C… Cylinder inner diameter, P… Liquid pressure.

Claims (2)

[Claims] 1. A tubular cylinder, a flange having a tubular protrusion that is attached to one end of the cylinder and that projects into the cylinder to form a space with a constant distance between the cylinder inner wall and the cylinder. It has a flange-like protruding defining member that defines a space between a cylinder slidably inserted between the cylinder and the protrusion and a protrusion of the flange into a pressure chamber and an air chamber, and has an inner peripheral portion. In addition, a small diameter portion through which the pressure liquid flows, a tapered portion that widens from the small diameter portion toward the protruding portion of the flange, and a large diameter portion that is continuous with the tapered portion through the step portion and the protruding portion is slidably inserted. And a tubular piston body having a tubular body, wherein the piston body is a pipe joint that receives a pushing force in one axial direction of the piston body by the hydraulic pressure of the pressure liquid introduced into the piston body, Diameter A, inner diameter B of large diameter part of piston body
And a piston body is formed such that the inner diameter C of the cylinder is C>A> B. Further, a communication hole communicating with the pressure chamber and the piston body is formed in the piston body, and the partition member is a liquid in the pressure chamber. A pipe joint that receives a pressure and receives a pressing force that balances in a direction opposite to the pressing force. 2. The pipe joint according to claim 1, wherein the cylinder is formed with an atmosphere introducing hole for introducing atmospheric pressure of outside air into the air chamber.