JP3936592B2 - Pipe fitting - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pipe joint used for connecting between a fluid device such as a hydraulic cylinder, a pneumatic cylinder, a valve device and a pipe body through which a fluid flows.
[0002]
[Prior art]
In general, various hydraulic equipment (fluid equipment) such as a hydraulic pump, a hydraulic cylinder, and a valve device are mounted on a construction machine such as a hydraulic excavator and a hydraulic crane used for civil engineering work at a construction site. And between these hydraulic equipment and piping (pipe body) through which pressure oil circulates, it has composition which is connected using a pipe joint.
[0003]
Therefore, a case where a hydraulic device or the like according to the prior art is mounted on a hydraulic excavator will be described as an example with reference to FIGS. 9 to 13.
[0004]
In the figure, reference numeral 1 denotes a side excavation type hydraulic excavator. The excavator 1 includes a crawler type lower traveling body 2, an upper revolving body 3 that is turnably mounted on the lower traveling body 2, and a later-described The front 4 is roughly constituted.
[0005]
Reference numeral 4 denotes a front provided on the front side of the upper swing body 3. The front 4 is disposed on the distal end side of the first boom 5A and the first boom 5A. A boom 5 comprising a second boom 5B mounted swingably in the left and right directions and a third boom 5C mounted swingably in the left and right directions on the distal end side of the second boom 5B; The arm 6 is attached to the front end side of 5C so as to be able to move up and down; It is configured.
[0006]
Reference numeral 8 denotes a boom cylinder provided between the upper swing body 3 and the first boom 5A. The boom cylinder 8 moves the first boom 5A up and down. Reference numeral 9 denotes an arm cylinder provided between the third boom 5C and the arm 6, and the arm cylinder 9 moves the arm 6 up and down on the distal end side of the third boom 5C. A bucket cylinder 10 is provided between the arm 6 and the bucket 7, and the bucket cylinder 10 rotates the bucket 7 on the tip side of the arm 6.
[0007]
Reference numeral 11 denotes an offset cylinder provided between the first boom 5A and the second boom 5B. The offset cylinder 11 swings the second boom 5B leftward and rightward on the tip side of the first boom 5A. is there. Here, the offset cylinder 11 is composed of a tube 11A, a piston 11B slidably fitted in the tube 11A, and a rod 11C attached to the piston 11B. The inside of the tube 11A is roded by the piston 11B. A side oil chamber 11D and a bottom oil chamber 11E are defined. The bottom side of the tube 11A is pivotally connected to the first boom 5A, and the distal end side of the rod 11C is pivotally connected to the second boom 5B.
[0008]
12 is a link provided between the first boom 5A and the third boom 5C in the vicinity of the offset cylinder 11, and one end side of the link 12 is rotatably coupled to the first boom 5A. The other end side is rotatably coupled to the third boom 5C. Here, the link 12 constitutes a parallel link together with the first boom 5A, the second boom 5B, and the third boom 5C, and holds the third boom 5C in parallel to the first boom 5A.
[0009]
Then, when the offset cylinder 11 is expanded and contracted and the second boom 5B swings left and right on the distal end side of the first boom 5A, the third boom 5C swings in the direction opposite to the second boom 5B by the link 12. It moves and always maintains a parallel posture with respect to the first boom 5A. As a result, the arm 6 and the bucket 7 disposed on the distal end side of the third boom 5C are translated (offset) in the left and right directions with respect to the first boom 5A. In this state, the boom cylinder 8 and the arm cylinder 9. By extending and retracting the bucket cylinder 10 and the like to operate the first boom 5A, the arm 6, the bucket 7, and the like, excavation work such as side grooves can be performed.
[0010]
Reference numeral 13 denotes a lock valve device as a hydraulic device fixed to the tube 11A of the offset cylinder 11 using a mounting band 14, and the lock valve device 13 includes a plurality of ports 15A and 15B as shown in FIGS. , 15C, 15D, and the like, and two lock valves 16, 16 provided in the casing 15.
[0011]
Here, each lock valve 16 is composed of, for example, a normally closed pilot operated check valve. When the offset cylinder 11 is operating properly, the lock valve 16 is kept open, and hydraulic hoses 20 and 22 described later are damaged. When proper operation of the offset cylinder 11 is impaired, the valve is closed and the offset cylinder 11 is held in an oil-locked state.
[0012]
Reference numerals 17 and 18 denote main pipes connecting the hydraulic pressure source 19 and the oil chambers 11D and 11E of the offset cylinder 11, and the lock valves 16 of the lock valve device 13 are respectively provided in the middle of the main pipes 17 and 18. Is provided. Here, the port 15A of the lock valve device 13 and the hydraulic pressure source 19 are connected via a hydraulic hose 20, and the hydraulic pressure consisting of a rigid steel pipe or the like is provided between the port 15B and the oil chamber 11D of the offset cylinder 11. It is connected via a pipe 21. Further, the port 15C of the lock valve device 13 and the hydraulic pressure source 19 are connected via a hydraulic hose 22, and the port 15D and the hydraulic chamber 11E of the offset cylinder 11 are connected by a hydraulic hose having flexibility. It is connected via a hose 23.
[0013]
In this case, the port 15B and the hydraulic pipe 21 of the lock valve device 13 (casing 15) and the port 15D and the hydraulic hose 23 are connected using the pipe joints 24, respectively. As shown in FIG. 12, the pipe joint 24 is formed of a cylindrical body having an oil passage 24A on the inner peripheral side, and a male screw 24B that is screwed into the port 15B (15D) is formed on one side in the axial direction. On the other side in the axial direction, a male screw 24C that is screwed into the hydraulic pipe 21 (hydraulic hose 23) is formed. Reference numeral 25 denotes a directional control valve located between the lock valve device 13 and the hydraulic source 19 and provided in the middle of the main pipelines 17 and 18. The directional control valve 25 is connected to the offset cylinder 11 from the hydraulic source 19. The direction of the pressure oil supplied and discharged to each oil chamber 11D, 11E is controlled.
[0014]
Here, when excavating the hydraulic excavator 1, for example, when the hydraulic hose 20 or the hydraulic hose 22 described above is damaged and oil leakage occurs, the weight on the front end side of the front 4 is received by the offset cylinder 11. Can not be. When one of the hydraulic hoses 20 and 22 breaks, for example, if the front 4 is in a posture as shown in FIG. 9, that is, if the bucket 7 is in a posture close to the upper swing body 3, the second boom 5B is There is a problem in that the weight of the front end of the front 4 swings left and right around the attachment portion with the first boom 5A, and the bucket 7 interferes with the cab 3A of the upper swing body 3 and the like.
[0015]
On the other hand, when one of the hydraulic hoses 20 and 22 is damaged and oil leakage occurs, the lock valve device 13 holds the offset cylinder 11 in the oil lock state, so that the second boom 5B is in the first state. It is the structure which prohibits rocking | fluctuating on the front end side of boom 5A.
[0016]
[Problems to be solved by the invention]
Here, when connecting between the oil chamber 11D of the offset cylinder 11 and the lock valve device 13 using the hydraulic piping 21, for example, one end of the hydraulic piping 21 is connected to the oil chamber 11D of the offset cylinder 11, The other end of the hydraulic pipe 21 faces the port 15B of the lock valve device 13.
[0017]
Then, for example, the male thread 24B of the pipe joint 24 is screwed into the port 15B of the lock valve device 13 while the mounting band 14 is loosened and the lock valve device 13 is moved in the direction of arrow A in FIG. The male screw 24C of the pipe joint 24 is screwed to the other end of the pipe. Thereby, the oil chamber 11 </ b> D of the offset cylinder 11 and the lock valve device 13 can be connected via the hydraulic pipe 21.
[0018]
In this case, since the hydraulic pipe 21 is formed of a rigid steel pipe or the like, the lock valve device 13 is in a state where the oil chamber 11D of the offset cylinder 11 and the lock valve device 13 are connected via the hydraulic pipe 21. It is fixed with respect to the offset cylinder 11 and cannot move in the direction of arrow B in FIG. Therefore, it is difficult to connect between the oil chamber 11E of the offset cylinder 11 and the lock valve device 13 using rigid hydraulic piping.
[0019]
For this reason, in the prior art, a flexible hydraulic hose 23 is used to connect between the oil chamber 11E of the offset cylinder 11 and the lock valve device 13, and one end of the hydraulic hose 23 is connected to the offset cylinder 11. The other end of the hydraulic hose 23 and the port 15B of the lock valve device 13 are connected using a pipe joint 24.
[0020]
Thus, in the prior art, between the port 15B of the lock valve device 13 and the hydraulic pipe 21, and between the port 15D of the lock valve device 13 and the hydraulic hose 23, male screws 24B, It connects using the pipe joint 24 in which 24C was formed. For this reason, the oil chamber 11E of the offset cylinder 11 and the lock valve device 13 must be connected using a hydraulic hose 23. The hydraulic hose 23 is less rigid than the hydraulic pipe 21 and easily breaks. There's a problem.
[0021]
On the other hand, as in another prior art shown in FIG. 13, for example, two lock valves 26 and 26 are separately attached to the offset cylinder 11, and the lock chambers 26 and the oil chambers 11D and 11E of the offset cylinder 11 are connected to each other. There is also a method of connecting the pipes without using piping or the like, but in this case, there is a problem that the number of parts increases by using two lock valves 26.
[0022]
The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a pipe joint that can reliably connect a fluid device and a rigid pipe body.
[0023]
[Means for Solving the Problems]
  In order to solve the above-mentioned problem, the invention of claim 1The one side is screwed to the port of the fluid device, and the other side is screwed to the female screw of the tube disposed with a space (S) between the fluid device and connects between the fluid device and the tube. A pipe joint,A hollow cylinder whose inner peripheral side is a passage and whose both axial ends are open ends, and is provided on one axial side of the cylinder.Screwed onto the port of the fluid deviceOne side male screw and provided on the other axial side of the cylinderScrewed onto the female thread of the tubeThe other side male screw, an intermediate male screw located between the one side male screw and the other side male screw and provided in the axial middle portion of the cylinder, and screwed to the middle male screw and movable in the axial direction With a movable nut,The overall length of the cylindrical body is such that when the one-side male screw is shifted to the port of the fluid device and screwed into the port, the other-side male screw faces the end of the tubular body, and the one-side male screw is used as the fluid device. The length of the other side male screw staying in the port of the fluid device when the other side male screw is screwed into the female screw of the pipe body by rotating in a direction away from the portMoving range of movable nut(B)The other side male thread length dimension(A)The configuration is set to be larger.
[0024]
  With this configuration, for example, when connecting a fluid device and a rigid tubular body using a pipe joint, first, the movable nut screwed into the intermediate male screw is moved to the other male screw side. In the state, once on the one side male screw fluid equipmentJust put it in the portScrew in. Then, in a state where the end of the tube body and the other side male screw face each other, the entire pipe joint is moved to the tube side by rotating the one side male screw in a direction away from the fluid device. Male thread of tubeFemale threadScrew on. Thereafter, the movable nut is rotated toward the one-side male screw by rotating on the intermediate male screw, and the one-side male screw is screwed to the fluid device by tightening the movable nut to the fluid device side.
[0025]
  Thus, a pipe joint connects between both by moving to an axial direction between a fluid apparatus and the edge part of a pipe body. In this case, between the other side male screw and the one side male screwScrewed into the middle male screwThe moving range of the movable nut to be moved is set to be larger than the length of the other male screw screwed to the end of the pipe body.Female threadIn this state, the movable nut can be tightened to the fluid device side with a margin, and the one-side male screw can be reliably screwed to the fluid device.
[0026]
The invention of claim 2 is that the length dimension of the internal thread of the movable nut is set larger than the length dimension of the intermediate external thread. With this configuration, for example, even when the length of the intermediate male screw is set to be short, a large moving range of the movable nut can be secured.
[0027]
According to a third aspect of the present invention, a tool engaging surface is provided on the outer peripheral side of the movable nut, and a fixed nut having a tool engaging surface is integrally provided between the other side male screw and the intermediate male screw in the cylindrical body. The tool engagement surface of the nut and the tool engagement surface of the fixed nut are formed to have substantially the same engagement width.
[0028]
With this configuration, when the other-side male screw is screwed onto the tube, a tool such as a spanner is engaged with the tool engaging surface of the fixing nut, and the other-side male screw is fastened to the tube using this tool. Can be included. Further, when the one-side male screw is screwed to the fluid device, the movable tool can be tightened to the fluid device side using the tool by engaging the same tool with the tool engaging surface of the movable nut.
[0029]
  In the invention of claim 4, between the one-side male screw and the movable nut, the movable nut can be moved in the axial direction together with the one-side male screw and the movable nut.Fluid deviceIn other words, a sealing member for sealing between the two is provided.
[0030]
  With this configuration, the movable nutFlowWhen the body member is tightened, the seal member is pressed against the fluid device by the movable nut, so that the fluid device and the one-side male screw can be sealed by the seal member.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the embodiment of the pipe joint according to the present invention will be described in detail with reference to FIGS. 1 to 8 by taking as an example a case where the embodiment is used between a lock valve device attached to an offset cylinder and a hydraulic pipe. . In the present embodiment, the same components as those of the above-described conventional technology are denoted by the same reference numerals, and the description thereof is omitted.
[0032]
In the figure, 31 is a hydraulic pipe connecting between the oil chamber 11E of the offset cylinder 11 and the port 15D of the lock valve device 13. The hydraulic pipe 31 is a steel pipe having rigidity unlike the hydraulic hose 23 according to the prior art. Etc. are used. One end of the hydraulic pipe 31 is connected to the oil chamber 11E of the offset cylinder 11, and the other end of the hydraulic pipe 31 is connected to the port 15D of the lock valve device 13 via a pipe joint 32 described later. Yes.
[0033]
Reference numeral 32 denotes a pipe joint that connects the other end of the hydraulic pipe 31 and the port 15D of the lock valve device 13. The pipe joint 32 is used in this embodiment in place of the pipe joint 24 according to the prior art. is there.
[0034]
  Here, as shown in FIGS. 2 to 4, the pipe joint 32 includes a hollow cylindrical cylinder 33 having an oil passage 33 </ b> A on the inner peripheral side and open ends on both axial sides, and a shaft of the cylinder 33. One side male screw 34 formed on one side in the direction and screwed to the port 15D of the lock valve device 13, and the other side male screw 35 formed on the other side in the axial direction of the cylinder 33 and screwed to the hydraulic pipe 31 An intermediate male screw 36 positioned between the one-side male screw 34 and the other-side male screw 35 and screwed to the intermediate portion in the axial direction of the cylindrical body 33, and an intermediate male screw 36 screwed to the intermediate male screw 36 and provided in the axial direction. The movable nut 37 that can be moved and a fixed nut 38 that is located between the other-side male screw 35 and the intermediate male screw 36 and is integrally formed with the cylindrical body 33 are generally configured.
  Further, the entire length of the cylindrical body 33 is formed longer than the interval S between the end of the casing 15 of the lock valve device 13 and the end of the hydraulic pipe 31 as shown in FIG. 6, when the one-side male screw 34 is screwed into the port 15D of the lock valve device 13 as shown in FIG. 6, the other-side male screw 35 faces the end of the hydraulic pipe 31. 7, when the one-side male screw 34 is rotated in a direction away from the port 15 </ b> D of the lock valve device 13 and the other-side male screw 35 is screwed into the female screw 31 </ b> A of the hydraulic pipe 31, the one-side male screw 34 is The length is set so as to be screwed into the 13 ports 15D.
[0035]
Here, the outer peripheral surface located between the one-side male screw 34 and the intermediate male screw 36 in the cylindrical body 33 becomes a cylindrical surface 33B having an outer diameter smaller than that of the intermediate male screw 36 or the like. The outer peripheral surface located between the male screw 35 and the intermediate male screw 36 is a cylindrical surface 33C having the same outer diameter as the cylindrical surface 33B. As shown in FIG. 4, an annular groove 33D surrounding the oil passage 33A is recessed in the other end surface of the cylinder 33, and an O-ring 39 is mounted in the annular groove 33D. ing.
[0036]
On the other hand, the one-side male screw 34, the other-side male screw 35, and the intermediate male screw 36 formed in the cylindrical body 33 are formed as male screws having, for example, equal outer diameter (tooth diameter) and pitch.
[0037]
Moreover, the movable nut 37 is comprised by the hexagonal nut in which the internal thread 37A was formed over the full length on the inner peripheral side, and the six tool engagement surfaces 37B are provided in the outer peripheral side. The movable nut 37 can move in the axial direction of the cylindrical body 33 between the position shown in FIG. 2 and the position shown in FIG. 3 by rotating the female screw 37 </ b> A into the intermediate male screw 36. It has a configuration.
[0038]
Here, as shown in FIG. 3 and the like, if the length dimension of the other-side male screw 35 is a, and the movement range (movement distance) of the movable nut 37 is b, the movement range b of the movable nut 37 is the other side. It is set larger than the length dimension a of the male screw 35 (b> a).
[0039]
If the length of the intermediate male screw 36 is c and the length of the female screw 37A of the movable nut 37 is d, the length d of the female screw 37A is larger than the length c of the intermediate male screw 36 ( d> c) is set.
[0040]
Further, when the length dimension of the one-side male screw 34 is e, the length dimension e of the one-side male screw 34 is set to be approximately equal to the length dimension a of the other-side male screw 35 (e≈a), and is intermediate. It is set larger than the length dimension c of the male screw 36 (e> c). Here, for example, when the male threads 34 and 35 are formed as 1/4 inch unified coarse threads, the above-described length dimensions a and e are set to 10 mm or more.
[0041]
The fixing nut 38 provided between the other-side male screw 35 and the intermediate male screw 36 has six tool engagement surfaces 38A formed on the outer peripheral side thereof. The engagement width of the tool engagement surface 38A provided on the fixed nut 38 and the engagement width of the tool engagement surface 37B provided on the movable nut 37 are formed to be substantially equal. The same spanner (not shown) can be engaged with the tool engagement surface 37B of the tool and the tool engagement surface 38A of the fixing nut 38.
[0042]
40 is an O-ring positioned between the one-side male screw 34 and the movable nut 37 and disposed on the outer peripheral side of the cylindrical surface 33B of the cylindrical body 33, and 41 is disposed between the movable nut 37 and the O-ring 40. In addition, the O-ring 40 and the washer 41 constitute a sealing member. The O-ring 40 and the washer 41 move together with the movable nut 37 in the axial direction of the cylindrical body 33 (cylindrical surface 33B), and the one-side male screw 34 is connected to the port of the lock valve device 13 using the movable nut 37 as will be described later. When screwed to 15D, the space between the one-side male screw 34 and the port 15D is sealed.
[0043]
The pipe joint 32 according to the present embodiment has the above-described configuration. Hereinafter, the operation of connecting the port 15D of the lock valve device 13 and the hydraulic pipe 31 using the pipe joint 32 will be described with reference to FIGS. This will be described with reference to FIG.
[0044]
In this case, it is assumed that the oil chamber 11D of the offset cylinder 11 and the port 15B of the lock valve device 13 are connected via a hydraulic pipe 21, a pipe joint 24, and the like, as in the conventional technique described above. Therefore, the lock valve device 13 is connected to the offset cylinder 11 via the rigid hydraulic pipe 21 and the like, and is fixed to the offset cylinder 11.
[0045]
In this state, first, as shown in FIG. 5, the movable nut 37 of the pipe joint 32 is rotated on the intermediate male screw 36, and the movable nut 37 is moved to a position where it abuts on the fixed nut 38 of the cylindrical body 33. deep.
[0046]
  Then, the one-side male thread 34 of the pipe joint 32 is placed in the port 15D of the lock valve device 13.Put togetherBy screwing, the entire pipe joint 32 is moved to the lock valve device 13 side to a position where the movable nut 37 abuts against the casing 15 of the lock valve device 13 via the washer 41 (a stroke end on one axial side). .
[0047]
Next, as shown in FIG. 6, the other end of the hydraulic pipe 31 faces the other male screw 35 of the pipe joint 32, and the axial centers of both are made coincident. In this case, by connecting one end of the hydraulic pipe 31 to the oil chamber 11E of the offset cylinder 11 in advance, a fixed interval that cannot be moved between the other end of the hydraulic pipe 31 and the lock valve device 13 is obtained. S is formed.
[0048]
  Next, as shown in FIG. 7, the one-side male screw 34 is rotated in a direction away from the port 15 </ b> D of the lock valve device 13, and the entire pipe joint 32 is moved to the hydraulic piping 31 side. As a result, the one-side male screw 34 is connected to the port 15D.InsideScrewed intoStayed in stateThe other side male screw 35 is screwed into a female screw 31 </ b> A formed at the other end of the hydraulic pipe 31.
[0049]
Then, the entire pipe joint 32 is moved to a position (a stroke end on the other side in the axial direction) where one end face of the cylinder 33 abuts against the bottom face 31B of the female thread 31A of the hydraulic pipe 31. In this case, the moving distance of the pipe joint 32 corresponds to the length dimension a of the other-side male screw 35 inserted into the end of the hydraulic pipe 31.
[0050]
In this state, a wrench (not shown) is engaged with the tool engagement surface 38A of the fixing nut 38 provided on the cylindrical body 33, and the other side male screw 35 is tightened using the wrench. Is screwed to the other end of the hydraulic pipe 31. In this case, since the length dimension a of the other-side male screw 35 is set to 10 mm or more, the other-side male screw 35 can be reliably screwed to the hydraulic pipe 31 with a sufficient depth.
[0051]
At this time, the O-ring 39 attached to the annular groove 33 </ b> D of the cylindrical body 33 is pressed against the bottom surface 31 </ b> B of the female screw 31 </ b> A of the hydraulic pipe 31, so that the gap between the other male screw 35 and the other end of the hydraulic pipe 31 is reached. Can be sealed.
[0052]
Next, as shown in FIG. 8, by rotating the movable nut 37 on the intermediate male screw 36 in the direction of detachment from the fixed nut 38, only the movable nut 37 is moved to the lock valve device 13 side. The movable nut 37 is abutted against the casing 15 of the lock valve device 13 via the washer 41.
[0053]
In this case, the movable range 37 of the movable nut 37 is set to be larger than the length dimension a of the other male screw 35 screwed to the other end of the hydraulic pipe 31, so that the movable nut 37 has a margin for the lock valve. It can move to the device 13 side and can strike the casing 15 via the washer 41 with certainty.
[0054]
Then, with the movable nut 37 abutting against the casing 15 via the washer 41, for example, the above-described spanner is engaged with the tool engagement surface 37B of the movable nut 37, and the movable nut 37 is tightened using this spanner. Thus, the one-side male screw 34 can be firmly screwed into the port 15D of the lock valve device 13. At this time, the O-ring 40 sandwiched between the casing 15 and the washer 41 is pressed against the casing 15, thereby sealing between the one-side male screw 34 and the port 15 </ b> D of the lock valve device 13. be able to.
[0055]
Thus, according to the present embodiment, even when the fixed interval S that cannot be moved is formed between the lock valve device 13 and the other end of the rigid hydraulic pipe 31, the lock valve device 13 The other side male screw 35 is screwed into the hydraulic pipe 31 by appropriately changing the screwing depth of the one side male thread 34 into the port 15D and moving the entire pipe joint 32 between the lock valve device 13 and the hydraulic pipe 31. After that, since the one-side male screw 34 can be screwed to the port 15D of the lock valve device 13 using the movable nut 37, between the port 15D of the lock valve device 13 and the other end of the hydraulic pipe 31 Can be reliably connected using the pipe joint 32.
[0056]
Accordingly, the oil chamber 11D of the offset cylinder 11 and the lock valve device 13 are connected by a rigid hydraulic pipe 21, and the oil chamber 11E of the offset cylinder 11 and the lock valve device 13 have a rigid hydraulic pressure. It can be connected by a pipe 31.
[0057]
For this reason, it is not necessary to use a hydraulic hose to connect between the oil chamber 11D of the offset cylinder 11 and the lock valve device 13 as in the prior art, for example, and it is possible to reliably avoid breakage of the hydraulic hose. Can do.
[0058]
In addition, since the pipe joint 32 connects between the port 15D of the lock valve device 13 and the other end of the hydraulic pipe 31 while appropriately moving, the pipe joint 32 is connected to the above, for example, due to an error in the length dimension of the hydraulic pipe 31 or the like. Even if the interval S changes, the error in the length dimension of the hydraulic pipe 31 can be absorbed, and the port 15D of the lock valve device 13 and the hydraulic pipe 31 can be reliably connected.
[0059]
Further, since the oil chambers 11D and 11E of the offset cylinder 11 and the lock valve device 13 can be connected using the rigid hydraulic pipes 21 and 31, for example, as in other conventional techniques, the offset It is not necessary to separately attach the two lock valves 26, 26 to the cylinder 11, and the number of parts can be reduced and the number of assembly steps can be reduced.
[0060]
In the above-described embodiment, the case where the port 15B of the lock valve device 13 and the hydraulic pipe 21 are connected using the same pipe joint 24 as in the prior art is taken as an example. However, the present invention is not limited to this, and the port 15B of the lock valve device 13 and the hydraulic pipe 21 may be connected using the pipe joint 32.
[0061]
Further, in the above-described embodiment, the case where the fixing nut 38 having the six tool engaging surfaces 38A is provided on the cylindrical body 33 constituting the pipe joint 32 is taken as an example. However, the present invention is not limited to this. For example, by chamfering the outer peripheral side of the cylindrical body 33, the cylindrical body 33 is provided with at least two tool engaging surfaces capable of engaging a tool such as a spanner. It is good.
[0062]
Moreover, in embodiment mentioned above, the lock valve apparatus 13 is illustrated as hydraulic equipment, and the case where the pipe joint 32 is used in order to connect between this lock valve apparatus 13 and the hydraulic piping 31 is mentioned as an example. . However, the present invention is not limited to this. For example, the hydraulic cylinder such as the boom cylinder 8, the arm cylinder 9 and the bucket cylinder 10; the hydraulic pump mounted on the hydraulic excavator; The pipe joint 32 can also be applied when connecting the two.
[0063]
Furthermore, in the above-described embodiment, the case where the hydraulic equipment mounted on the hydraulic excavator and the hydraulic piping are connected using the pipe joint 32 is illustrated, but the present invention is not limited to this, for example, a pneumatic cylinder It may be used to connect a pneumatic device such as a pneumatic pipe.
[0064]
【The invention's effect】
  As detailed above, the pipe joint according to the invention of claim 1The one side is screwed to the port of the fluid device and the other side is screwed to the female screw of the tubular body arranged with a space between the fluid device, thereby connecting the two. Rotate the full length of the one-side male screw to the port of the fluid device when the other-side male screw faces the end of the tube when the one-side male screw is shifted to the fluid device port. Set the length so that one side male screw stays in the port of the fluid device when the other side male screw is screwed into the female screw of the pipe body,It is set as the structure which sets the moving range of a movable nut larger than the length dimension of an other side male screw. For this reason,SpacedWhen connecting a fluid device and a rigid tubular body using a pipe joint,PortBy appropriately changing the threading depth of the one-side male screw with respect to, the entire pipe joint is moved between the fluid device and the pipe body,Leave one side male screw in the port of the fluid device,Tube on the other sideFemale threadScrewed oncan do. In this state, move the movable nut to the fluid device side., Fluid equipment with one side male screw using a movable nutPortCan be screwed on. In this case, since the movable range of the movable nut is set to be larger than the length dimension of the other side male screw to be screwed to the pipe body, the movable nut is securely screwed to the pipe body. Can be tightened to the fluid device side, and the one-side male screw can be securely fixed to the fluid device.
[0065]
Therefore, even when there is a certain interval that cannot be moved between the fluid device and the rigid pipe body, it is possible to reliably connect the two via a pipe joint. It is not necessary to use a flexible tubular body such as a hydraulic hose in place of the tubular body, and it is possible to reliably avoid breakage of the hydraulic hose and improve the reliability of fluid equipment and the like. .
[0066]
According to the invention of claim 2, since the length dimension of the internal thread of the movable nut is set larger than the length dimension of the intermediate male thread, for example, even when the length dimension of the intermediate male thread is set short, the movable nut A large movement range can be secured.
[0067]
According to the invention of claim 3, the tool engagement surface having an engagement width substantially equal to the tool engagement surface provided on the movable nut is provided between the other side screw and the intermediate screw in the cylindrical body. The fixing nut is integrally provided. Thus, for example, when the other side male screw is screwed to the pipe body, a tool such as a spanner can be engaged with the tool engaging surface of the fixing nut, and the other side male screw can be securely screwed to the pipe body. When the side male screw is screwed to the fluid device, the same tool can be engaged with the tool engaging surface of the movable nut, and the movable nut can be tightened to the fluid device side using the tool.
[0068]
Furthermore, according to the invention of claim 4, since the seal member that is movable in the axial direction together with the movable nut is provided between the one-side male screw and the movable nut, the movable nut is tightened to the fluid device side. Since the seal member is pressed against the fluid device by the movable nut when it is inserted, the seal member can seal between the fluid device and the one-side male screw.
[Brief description of the drawings]
FIG. 1 is a front view showing an offset cylinder, a lock valve device, hydraulic piping, etc. to which an embodiment of a pipe joint according to the present invention is applied.
FIG. 2 is a front view showing the pipe joint according to the present embodiment in a state where the movable nut is moved to the other male screw side.
FIG. 3 is a front view similar to FIG. 2 showing the pipe joint in a state where the movable nut has moved to the one-side male screw side.
4 is a cross-sectional view of the pipe joint as viewed from the direction of arrows IV-IV in FIG.
FIG. 5 is an operation process diagram showing a state in which one side male thread of a pipe joint is screwed into a port of the lock valve device in order to connect between the lock valve device and the hydraulic pipe.
FIG. 6 is an operation process diagram showing a state in which the other side male screw of the pipe joint and the hydraulic pipe are faced to each other.
FIG. 7 is an operation process diagram showing a state in which the other side male screw of the pipe joint is screwed to the hydraulic pipe.
FIG. 8 is an operation process diagram illustrating a state in which a movable nut is tightened and a one-side male screw is screwed to a port of a lock valve device.
FIG. 9 is an external view showing a hydraulic excavator including an offset cylinder, a lock valve device, and the like connected using a pipe joint according to the prior art.
FIG. 10 is a front view showing an offset cylinder, a lock valve device, hydraulic piping, etc. to which a pipe joint according to the prior art is applied.
FIG. 11 is a hydraulic system diagram including a hydraulic cylinder, a lock valve device, hydraulic piping, and the like.
12 is a front view showing the pipe joint in FIG. 10. FIG.
FIG. 13 is a front view showing another prior art in which two lock valves are directly attached to an offset cylinder.
[Explanation of symbols]
11 Offset cylinder
13 Lock valve device (hydraulic equipment)
31 Hydraulic piping (pipe)
32 Pipe fittings
33 cylinder
33A Oil passage
34 One side male thread
35 Other side male thread
36 Intermediate male screw
37 Movable nut
37A Female thread
37B Tool engagement surface
38 Fixing nut
38A Tool engagement surface
40 O-ring (seal member)
41 Washer (seal member)

Claims (4)

One side is screwed to the port of the fluid device, and the other side is screwed to the female screw of the tube disposed with a space (S) between the fluid device and the pipe connecting the fluid device and the tube A joint,
A hollow cylinder whose inner peripheral side is a passage and whose both axial ends are open ends, a one-side male screw that is provided on one side in the axial direction of the cylinder and screwed into a port of the fluid device, and the cylinder The other side male screw that is provided on the other side in the axial direction of the tube and is screwed to the female screw of the tubular body, and is provided between the one side male screw and the other side male screw and is provided in the intermediate portion in the axial direction of the cylindrical body. An intermediate male screw and a movable nut that is screwed to the intermediate male screw and is movable in the axial direction ;
The overall length of the cylindrical body is such that when the one-side male screw is shifted to the port of the fluid device and screwed into the port, the other-side male screw faces the end of the tubular body, and the one-side male screw is used as the fluid device. Set to a length that the one-side male screw stays in the port of the fluid device when the other-side male screw is screwed into the female screw of the tubular body by rotating in a direction away from the port.
And the pipe joint comprised as a structure which sets the moving range (b) of the said movable nut larger than the length dimension (a) of the said other side external thread. The pipe joint according to claim 1, wherein a length dimension (d) of the internal thread of the movable nut is set larger than a length dimension (c) of the intermediate external thread.   A tool engaging surface is provided on an outer peripheral side of the movable nut, and a fixed nut having a tool engaging surface is integrally provided between the other side male screw and the intermediate male screw in the cylindrical body, and the tool of the movable nut is provided. The pipe joint according to claim 1 or 2, wherein the engagement surface and the tool engagement surface of the fixing nut are formed to have substantially the same engagement width. The structure according to claim 1, 2 or 2, wherein a seal member is provided between the one-side male screw and the movable nut so as to be movable in the axial direction together with the movable nut and seal between the one-side male screw and the fluid device. 3. The pipe joint according to 3.

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