JP4262643B2 - Hydraulic cylinder holding valve mounting structure - Google Patents

Description

  The present invention relates to a valve mounting structure for a hydraulic cylinder that drives a work machine, and more particularly to a valve mounting structure for a hydraulic cylinder in which a pipe break control valve that prevents a load from dropping when the hydraulic pipe for a cylinder is broken is attached to the hydraulic cylinder. .

  A hydraulic machine, for example, a hydraulic excavator, is connected to a lower traveling body, an upper revolving body provided on the lower traveling body so as to be able to swivel, and an upper revolving body so as to be able to be turned up and down. , Breaker, crusher, etc.). Further, for example, an offset hydraulic excavator has a boom divided into a lower boom and an upper boom, and the upper boom is attached to the lower boom so as to be rotatable in the left-right direction. In these excavators, there is a need to prevent the load from dropping (moving) even if the hydraulic pipe (hose or steel pipe) that transports the pressure oil to the hydraulic cylinder that drives the load such as boom and arm should be damaged. In order to cope with this, a pipe breakage control valve (hose rupture valve) is provided between the hydraulic cylinder and the hydraulic pipe.

  The pipe break control valve has a poppet valve body as a main valve that cuts off and communicates between the hydraulic cylinder side and the hydraulic pipe side, and a spool valve body as a pilot valve connected to a back pressure chamber of the poppet valve body. . During normal operation, the poppet valve body is brought into a communication state by operating the spool valve body by an external signal (pilot pressure from the hydraulic pilot type operation lever device) so that the pressure oil from the hydraulic cylinder flows out. It has become. Also, when the hydraulic piping breaks, the poppet valve body is held at the shut-off position and functions as a load check valve to prevent pressure oil from flowing out of the hydraulic cylinder and to prevent dropping of loads such as booms and arms. It is like that.

  Here, conventionally, for example, a configuration in which a pipe breakage control valve (holding function valve) is provided between an offset hydraulic cylinder that drives an upper boom and a hydraulic pipe is disclosed (for example, see Patent Document 1). In this prior art, the pipe breakage control valve is attached to the offset hydraulic cylinder by a band member wound around the offset hydraulic cylinder.

JP 2000-64345 A

However, there are the following problems in the above-described prior art.
That is, hydraulic machines such as hydraulic excavators have different sizes of hydraulic cylinders depending on their specifications (mass, horsepower, etc.), and the band members for installing the pipe break control valves are respectively set according to the diameter dimensions of the hydraulic cylinders. There was room for improvement in terms of cost because it had to be prepared.

  An object of the present invention is to provide a valve mounting structure for a hydraulic cylinder that can share valve mounting components in hydraulic cylinders having different diameters and can reduce costs.

(1) In order to achieve the above object, the present invention is provided between a supply / discharge port of a cylindrical hydraulic cylinder that drives a work machine and a hydraulic pipe, and is connected to the supply / discharge port according to an external signal. In a valve mounting structure of a hydraulic cylinder in which a pipe breakage control valve for controlling the flow rate of pressure oil flowing out to the hydraulic pipe is attached to the hydraulic cylinder, at least two disposed at a predetermined radial angle interval on a cylinder outer periphery of the hydraulic cylinder. And has a valve mounting means to which the pipe break control valve can be mounted and is in contact with the hydraulic cylinder in a plane perpendicular to the longitudinal direction of the hydraulic cylinder formed corresponding to the screw seat of the hydraulic cylinder. A valve fitting having a long hole in the tangential direction; and a fixing bolt that is inserted into the long hole of the valve fitting and is screwed into the corresponding screw seat of the hydraulic cylinder.

  In the present invention, at least two screw seats are disposed on the cylinder outer periphery of the hydraulic cylinder, and the radial angle intervals (and axial intervals) of these screw seats are made common. And in the valve fixture which can attach a pipe fracture control valve, in order to respond | correspond to the screw seat of the hydraulic cylinder from which a diameter size changes with airframes, uses, etc., a long elongate hole is formed in the tangential direction of a hydraulic cylinder. Thereby, even when the diameter dimensions of the hydraulic cylinder are different, the fixing bolt can be inserted into the elongated hole of the valve fitting and screwed into the screw seat of the corresponding hydraulic cylinder to fix the valve fitting to the hydraulic cylinder. Therefore, it is possible to share the valve fittings in the hydraulic cylinders having different diameters, and the cost can be reduced.

  (2) In the above (1), preferably, a protective device for covering the pipe breakage control valve is further provided, and the valve mounting device has a protective device mounting means to which the protective device can be mounted.

  (3) In the above (1) or (2), preferably, the screw seats of the hydraulic cylinder are arranged at a radial angle interval of 90 degrees on the outer peripheral portion of the hydraulic cylinder.

  (4) In any one of the above (1) to (3), preferably, the pipe breakage control valve is attached so as to be disposed on the left and right side surfaces of the hydraulic cylinder.

  According to the present invention, it is possible to share a valve mounting component in hydraulic cylinders having different diameters, thereby reducing costs.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing the entire structure of a small-sized hydraulic excavator capable of carrying a suspended load work to which the present invention is applied. Hereinafter, when the operator is seated in the driver's seat with the excavator shown in FIG. 1, the front side (left side in FIG. 1), rear side (right side in FIG. 1), left side (paper surface in FIG. 1). The front side) and the right side (back side toward the paper surface in FIG. 1) are simply referred to as front side, rear side, left side, and right side.

  In FIG. 1, this hydraulic excavator includes a lower traveling body 2 provided with left and right endless track tracks (crawlers) 1L and 1R (only 1L is shown in FIG. 1) as traveling means, and the lower traveling body 2 The upper revolving unit 3 provided at the upper part is configured to be pivotable, and the swivel frame 4 that forms the basic lower structure of the upper revolving unit 3 is mounted so as to be pivotable in the horizontal direction around a vertical pin (not shown). The swing post 5, an articulated front work machine 6 provided on the swing post 5 so as to be pivotable (can be raised and lowered), and a so-called canopy type cab 7 provided on the revolving frame 4. And an upper cover 8 that covers most of the swivel frame 4 other than the cab 7.

  The lower traveling body 2 includes a substantially H-shaped track frame 9, drive wheels 10 </ b> L and 10 </ b> R (only 10 </ b> L is shown in FIG. 1) rotatably supported on the left and right sides of the track frame 9, and drive wheels Left and right traveling hydraulic motors 11L and 11R for driving 10L and 10R, respectively (however, only 11L is shown in FIG. 1), and rotatably supported on both the left and right sides of the track frame 9, are driven through the crawler belts 1L and 1R. Driven wheels (idlers) 12L and 12R (only 12L shown in FIG. 1) rotated by the driving force of the wheels 10L and 10R, and a track frame 9 are provided to be movable up and down, and a hydraulic cylinder for blades (not shown). ) And a blade 13 for soil removal that moves up and down. In addition, a swivel bearing (swivel wheel) 14 is disposed in the center of the lower traveling body 2, and a swing hydraulic motor (not shown) is disposed in the vicinity of the center of the swirling wheel 14 to rotate the swing frame 4 relative to the lower traveling body 2. Z) is built-in.

  The swing post 5 can be horizontally rotated with respect to the revolving frame 4 via a vertical pin (not shown). The swing post 5 is connected to a swing hydraulic cylinder 15 provided on the revolving frame 4 via a connecting pin (not shown), and the swing post 5 extends and contracts as a whole in the vertical direction. The front work machine 6 swings to the left and right by rotating around the center of the axis.

  The front work machine 6 includes a boom 16, an arm 17 that is rotatably connected to the boom 16, and a bucket 18 that is rotatably connected to the arm 17. The boom 16, the arm 17, and the bucket 18 are operated by a boom hydraulic cylinder 19, an arm hydraulic cylinder 20, and a bucket hydraulic cylinder 21, respectively. In addition, a hook 23 for suspending the suspended load 22 is provided near the distal end portion of the arm 17 during a suspended load operation described later. However, normally, the bucket hydraulic cylinder 21 is not driven during a suspended work. In addition, the boom hydraulic cylinder 19 and the arm hydraulic cylinder 20 are each provided with a pipe break control valve (hose rupture valve) 24 for preventing outflow of pressure oil even if the hydraulic pipe is broken. .

  A boom angle sensor 25 for detecting the rotation angle of the boom 16 with respect to the revolving frame 4 is attached to the rotation base of the boom 16, and the rotation angle of the arm 17 with respect to the boom 16 is attached to the rotation base of the arm 17. An arm angle sensor 26 for detecting the above is attached. Further, pressure sensors (not shown) for detecting the pressures of the rod side oil chamber and the bottom side oil chamber of the boom hydraulic cylinder 19 are attached.

  The control device (not shown) inputs the detected rotation angles of the boom 16 and the arm 17 and the pressures of the rod-side oil chamber and the bottom-side oil chamber of the boom hydraulic cylinder 19 to perform predetermined calculation processing (details). First, the holding force moment of the boom hydraulic cylinder 19 is calculated from the pressures in the rod side oil chamber and the bottom side oil chamber, and the moment of the front working machine 6 and the position of the suspended load 22 are calculated from the boom angle, arm angle, and the like. Then, the difference between the holding force moment and the moment of the front work machine 6 becomes the moment of the suspended load 22, and the suspended load W is calculated by this moment).

The driver's cab 7 is provided on the left side of the revolving frame 4 described above, and a seat (driver's seat) 27 on which an operator is seated, a roof 28 provided above the seat 27, and the roof 28 are supported. And a supporting column 29.

  In front of the seat 27, left and right traveling operation levers 30L and 30R that can be operated with both hands and feet for driving the left and right traveling hydraulic motors 11L and 11R to move the hydraulic excavator forward or backward, for example. (However, only 30L is shown in FIG. 1). Further, on the left side of the seat 27, the swing hydraulic motor is driven by operating the left or right side to rotate the upper swing body 3 to the left or right side, and the arm hydraulic cylinder is operated by operating the front or rear side. An operation lever device 32L (see FIG. 2 described later) including a cross operation type swivel / arm manual operation lever 31L that drives 20 to dump or cloud the arm 17 is provided. On the right side of the seat 27, the bucket hydraulic cylinder 21 is driven by operating the left or right side to cause the bucket 18 to cloud or dump, and the boom hydraulic cylinder 19 is driven by operating the front or rear side. Operating lever device 32R (not shown) having a cross-operating bucket boom manual operation lever 31R (not shown) for lowering or raising the boom 16, and various indications (the position of the suspended load 22 and the position of the suspended load 22) And a display device 33 for displaying the rated load Wm, the suspension load W, and the like.

  The upper cover 8 includes an engine (not shown), a hydraulic pump 34 (see FIG. 2 described later) driven by the engine, and a hydraulic oil tank 35 (described later) serving as a pressure oil source for the hydraulic pump 34. (See FIG. 2).

  In the configuration described above, the left / right endless track crawler tracks 1L and 1R, the upper swing body 3, the swing post 5, the blade 13, the boom 16, the arm 17, and the bucket 18 are driven by a hydraulic drive device provided in the hydraulic excavator. A driven member to be driven is configured.

  FIG. 2 is a hydraulic circuit diagram illustrating an example of a configuration of a main part related to driving of the arm 17 in the hydraulic driving device.

  In FIG. 2, the hydraulic oil tank 35, the hydraulic pump 34, the arm hydraulic cylinder 20 driven by the pressure oil discharged from the hydraulic pump 34, and the hydraulic pump 34 to the arm hydraulic cylinder 20. Hydraulic pilot type arm control valve 36 for controlling the flow of supplied pressure oil, hydraulic piping (actuator lines) 37A and 37B connected to actuator ports 36a and 36b of the arm control valve 36, and these An operation lever device 32L provided with main overload relief valves 38A and 38B provided on the hydraulic pipes 37A and 37B for limiting the maximum pressure in the circuit, the manual operation lever 31L for instructing the operation of the arm 17, and the above A pipe breakage control valve 24 is provided.

  The operation lever device 32L and the manual operation lever 31L and a pressure reducing valve (secondary pilot pressure) for outputting an operation pilot pressure (secondary pilot pressure) obtained by reducing the primary pilot pressure from a pilot pump (not shown) according to the operation amount. (Not shown). When the manual operation lever 31L is operated, for example, in the direction of arrow A in FIG. To the pilot pressure receiving portion 36c (or 36d), thereby switching the arm control valve 36 to the upper position (or lower position) in FIG. The operation pilot pressure when the manual operation lever 31L is operated in the arrow B direction is also output to the pipe breakage control valve 24.

  The pipe breaking control valve 24 has a housing 40 (see FIG. 5 described later) provided with input / output ports 39a and 39b, a pilot port 39c, and a drain port 39d. The input / output port 39a is connected to the first supply / discharge port 20a opened to the rod side oil chamber of the arm hydraulic cylinder 20 via the hydraulic pipe 41, and the input / output port 39b is connected to the arm control valve 36 via the hydraulic pipe 37A. Connected to the actuator port 36a. The actuator port 36b of the arm control valve 36 is connected to a second supply / discharge port 20b that opens to the bottom side oil chamber of the arm hydraulic cylinder 20 via a hydraulic pipe 37B. The pilot port 39c is connected to the operation lever device 32L via a hydraulic pipe (pilot line) 42, and the drain port 39d is connected to the hydraulic oil tank 35 via a hydraulic pipe (drain line) 43.

  The pipe break control valve 24 includes a poppet valve body 44 as a main valve, a spool valve body 45 as a pilot valve that is operated by an operation pilot pressure from the operation lever device 32L, and a small valve having the functions of an overload relief valve. A relief valve 46 is provided. The poppet valve body 44 has a cylinder connection chamber 47a connected to the input / output port 39a, a pipe connection chamber 47b connected to the input / output port 39b, and a back connected to the input / output port 39a via the spool valve body 45. A pressure chamber 47c and a spring 47d disposed in the back pressure chamber 47c are provided. The poppet valve body 44 moves in a balance between the acting force due to the pressure in the cylinder connection chamber 47a and the piping connection chamber 47b and the acting force due to the pressure in the back pressure chamber 47c and the biasing force of the spring 47d. The piping connection chamber 47b is switched between a disconnected state (position shown in FIG. 2) and a communicating state, and the opening area is changed according to the amount of movement.

  The spool valve body 45 is provided with a spring 48a for setting an initial valve opening force at the valve closing direction operating end, and is connected to the pilot port 39c at the valve opening direction operating end, and is operated from the operation lever device 32L. A pilot pressure receiving portion 48b to which pressure is input is provided. The spool valve body 45 is moved by the control force by the operating pilot pressure (external signal) of the pilot pressure receiving portion 48b and the biasing force of the spring 48a, and the back pressure chamber 47c of the poppet valve body 44 communicates with the input / output port 39a. The state is switched to the state (left position in FIG. 2) and the state connected to the drain port 39d (right position in FIG. 2), and the opening area is changed according to the amount of movement.

  The inlet side of the small relief valve 46 is connected to the input / output port 39a, and the outlet side of the small relief valve 46 is connected to the drain port 39d via the drain passage 49a. The drain passage 49a is provided with a throttle 49b as pressure generating means, and the pressure generated by the throttle 49b is provided between the small relief valve 46 and the throttle 49b in the pilot pressure receiving portion 48c (described above) of the spool valve body 45. A signal passage 49c introduced into a pilot pressure receiving portion (acting as a driving force on the same side as the operation pilot pressure) is branched.

  Next, the operation of the pipe breakage control valve 24 will be described below.

(1) Normal operation For example, when the manual operation lever 31L is operated in the direction of arrow A in FIG. 2 and the arm control valve 36 is switched to the upper position in FIG. Is supplied to the pipe connection chamber 47b of the poppet valve body 44, and the pressure in the pipe connection chamber 47b rises. At this time, the pressure in the cylinder connection chamber 47a of the poppet valve body 44 becomes the pressure in the rod side oil chamber of the arm hydraulic cylinder 20, and the back pressure chamber 47c communicates with the spool valve body 45 at the left position in FIG. Therefore, the pressure in the back pressure chamber 47c of the poppet valve body 44 also becomes the pressure in the rod side oil chamber. Therefore, as long as the pressure in the pipe connection chamber 47b is lower than the pressure in the rod side oil chamber, the poppet valve body 44 is kept in the blocking position. On the other hand, as soon as the pressure in the pipe connection chamber 47b becomes higher than the pressure in the rod side oil chamber, the poppet valve body 44 immediately moves to the right side in FIG. 2, allowing pressure oil to flow out from the pipe connection chamber 47b to the cylinder connection chamber 47a. The pressure oil from the hydraulic pump 34 is supplied to the supply / discharge port 20 a of the arm hydraulic cylinder 20. At the same time, the pressure oil from the supply / discharge port 20 b of the arm hydraulic cylinder 20 is discharged to the hydraulic oil tank 35 via the arm control valve 36.

  Further, for example, when the manual operation lever 31L is operated in the direction of arrow B in FIG. 2 and the arm control valve 36 is switched to the lower position in FIG. 2, the pressure oil from the hydraulic pump 34 passes through the arm control valve 36 to the arm. Is supplied to the supply / discharge port 20 b of the hydraulic cylinder 20. At the same time, the operation pilot pressure from the operation lever device 32L is input to the pilot pressure receiving portion 48b of the spool valve body 45, and the spool valve body 45 moves to the left in FIG. Pressure oil can flow out from the back pressure chamber 47c to the drain port 39d, and the pressure in the back pressure chamber 47c decreases. As a result, the poppet valve body 44 moves to the right side in FIG. 2 and pressure oil can flow out from the cylinder connection chamber 47a to the pipe connection chamber 47b. The pressure oil from the supply / discharge port 20a of the arm hydraulic cylinder 20 is used for the arm. The oil is discharged to the hydraulic oil tank 35 through the control valve 36.

(2) When the pipe breaks In the unlikely event that the hydraulic pipe 37A breaks, the poppet valve body 44 is kept in the shut-off position, preventing the pressure oil from flowing out from the supply / discharge port 20a of the arm hydraulic cylinder 20, and the arm 17 Prevent the fall (movement) of the.

  Next, the mounting structure of the pipe breakage control valve 24, which is a main part of the present invention, will be described.

  FIG. 3 is a partially enlarged side view of a portion III in FIG. 1 and shows a mounting structure of the pipe breakage control valve 24 according to the present embodiment. FIG. 4 is a sectional view taken along a section IV-IV in FIG. FIG. 5 is a side view as seen from the direction of the arrow V in FIG. 4 and shows a state in which a protector described later is removed. FIG. It is sectional drawing by middle section VI-VI.

  3 to 6, the pipe break control valve 24 is attached and the valve fitting 50 fixed to the arm hydraulic cylinder 20 and the protection for covering the pipe break control valve 24 attached to the valve fitting 50. A tool 51 is provided.

  Two screw seats 52 are arranged on the cylinder outer peripheral portion 20c of the arm hydraulic cylinder 20 with a predetermined radial angle interval θ (for example, 90 °) and a predetermined axial direction interval L.

  The valve mounting tool 50 includes a first flat portion 53a to which the pipe breakage control valve 24 can be attached and an inner side at an angle (180 ° −θ) = 90 ° from one end side (upper side in FIG. 6) of the first flat portion 53a. A second plane part 53b bent to the right (in FIG. 6) and a third plane part 53c bent from the other end side (the lower side in FIG. 6) to the outside (the left side in FIG. 6) of the first plane part 53a. It consists of and. At this time, the first plane portion 53a and the second plane portion 53b are perpendicular to the screwing direction of the screw seat 52 of the arm hydraulic cylinder 20, respectively.

  Two screw seats 54 are provided at positions corresponding to two through holes (not shown) formed in the housing 40 of the pipe breakage control valve 24 in the first flat portion 53a of the valve fitting 50. . Then, the pipe breakage control valve 24 is attached to the valve fitting 50 by inserting the mounting bolt 55 into the through hole of the housing 40 of the pipe breakage control valve 24 and screwing it into the screw seat 54 of the corresponding valve fitting 50. It has become.

  Further, the first flat surface portion 53a and the second flat surface portion 53b of the valve fitting 50 are respectively connected to the positions corresponding to the screw seats 52 of the arm hydraulic cylinder 20 in the tangential direction (left and right in FIG. 6). A long slot 56 is formed in the direction (vertical direction). Then, the fixing bolt 57 is inserted into the elongated hole 56 of the valve fitting 50 and screwed into the screw seat 52 of the corresponding arm hydraulic cylinder 20 so that the valve fitting 50 is fixed to the arm hydraulic cylinder 20. It has become. At this time, in this embodiment, the pipe breakage control valve 24 is arranged on the substantially left side of the arm hydraulic cylinder (see FIG. 4). In addition, the long hole 56 formed in the 1st plane part 53a is a position which does not interfere with the pipe fracture control valve 24.

  Further, the second flat portion 53b and the third flat portion 53c of the valve fitting 50 are provided with two screw seats 58, and through holes (not shown) formed in the protector 51 with mounting bolts 59. The protector 51 is attached to the valve attachment 50 by being screwed into the screw seat 58 of the valve attachment 50 corresponding to the insertion.

  The valve fitting 50 and the protector 51 interfere with the ports (specifically, the input / output ports 39a and 39b, the pilot port 39c, and the drain port 39d) of the pipe breakage control valve 24 and the hydraulic piping connected thereto. It has a structure that does not.

  In the above description, the screw seat 54 and the mounting bolt 55 of the valve fixture 50 constitute valve mounting means to which the pipe breakage control valve described in the claims can be attached, and the screw seat 58 and the mounting of the valve fixture 50. The bolt 59 constitutes a protector attachment means to which the protector described in the claims can be attached.

  In the above, the mounting structure of the pipe break control valve 24 has been described in detail by taking the arm hydraulic cylinder 20 as an example, but the mounting structure of the pipe break control valve 24 in the boom hydraulic cylinder 19 has the same configuration. Description is omitted.

  As described above, in the present embodiment, the two screw seats 52 are disposed on the outer circumferences of the boom hydraulic cylinder 19 and the arm hydraulic cylinder 20, respectively, and the radial angle interval θ and the axial interval of the screw seats 52 are arranged. Let L be the same. The valve fitting 50 to which the pipe breakage control valve 24 can be attached is long in the tangential direction of the hydraulic cylinders 19 and 20 so as to be compatible with the screw seats 52 of the hydraulic cylinders 19 and 20 having different diameters depending on the machine body. A long hole 56 is formed. Accordingly, even when the diameter dimensions of the hydraulic cylinders 19 and 20 differ depending on the machine body, the fixing bolt 57 is inserted into the elongated hole 56 of the valve fitting 50 and screwed into the corresponding screw seat 52 of the hydraulic cylinders 19 and 20, so that the valve fitting 50 can be fixed to the hydraulic cylinders 19 and 20. Therefore, it is possible to share the valve fitting 50 in the hydraulic cylinders 19 and 20 having different diameters, and the cost can be reduced.

  Further, by fixing the valve fitting 50 so that the pipe break control valve 24 is disposed on the left and right side surfaces (in the present embodiment, substantially the left side surface) of the hydraulic cylinders 19 and 20, the pipe break control valve 24 is It is possible to prevent damage caused by interference with the suspended load 22 or surrounding obstacles. Moreover, since the protector 51 for covering the pipe breakage control valve 24 is attached, damage to the pipe breakage control valve 24 can be further prevented.

  In the above-described embodiment, the pipe break control valve 24 connected between the rod-side supply / discharge port 20a of the arm hydraulic cylinder 20 and the hydraulic pipe 37A has been described as an example, but the present invention is not limited thereto. That is, for example, the pipe break control valve 24 may be connected between the supply / discharge port on the bottom side of the hydraulic cylinder and the hydraulic pipe, or both may be provided. In these cases, the same effect as described above can be obtained. .

  In the above-described embodiment, the case where the pipe breakage control valve 24 is attached to the boom hydraulic cylinder 19 and the arm hydraulic cylinder 20 in the hydraulic excavator capable of carrying a suspended load is described as an example, but the present invention is not limited thereto. . That is, it goes without saying that the present invention may be applied to the case where the pipe break control valve 24 is attached to an offset hydraulic cylinder of an offset hydraulic excavator, for example.

It is a side view showing the whole structure of the small hydraulic excavator which is the application object of the valve mounting structure of the hydraulic cylinder of the present invention. It is a hydraulic circuit diagram showing the principal part structure regarding the drive of an arm among the hydraulic drive devices with which the hydraulic shovel which is the application object of the valve mounting structure of the hydraulic cylinder of this invention was equipped. It is the elements on larger scale by the III section in Drawing 1, and shows one embodiment of the valve mounting structure of the hydraulic cylinder of the present invention. FIG. 4 is a sectional view taken along section IV-IV in FIG. 3. FIG. 4 is a side view as seen from the direction of arrow V in FIG. It is sectional drawing by the cross section VI-VI in FIG.

Explanation of symbols

6 Front working machine 19 Boom hydraulic cylinder 20 Arm hydraulic cylinders 20a, 20b Supply / exhaust port 20c Cylinder outer peripheral portion 24 Pipe break control valve 37A Hydraulic pipe L Axial interval θ Diameter angle interval 50 Valve fitting 51 Protective tool 52 Screw seat 54 Screw seat (valve mounting means)
55 Mounting bolt (Valve mounting means)
56 Long hole 57 Fixing bolt 58 Screw seat (Protective equipment mounting means)
59 Mounting bolt (Protective equipment mounting means)

Claims (4)

Pipe breakage control that is provided between the supply and discharge port of the cylindrical hydraulic cylinder that drives the work machine and the hydraulic pipe and controls the flow rate of the pressure oil that flows from the supply and discharge port to the hydraulic pipe according to an external signal In the valve mounting structure of the hydraulic cylinder in which the valve is mounted on the hydraulic cylinder,
At least two screw seats disposed at a predetermined radial angle interval on the outer periphery of the hydraulic cylinder;
The valve has a valve mounting means to which the pipe break control valve can be mounted, and is long corresponding to the tangential direction in contact with the hydraulic cylinder in a plane perpendicular to the longitudinal direction of the hydraulic cylinder formed corresponding to the threaded seat of the hydraulic cylinder. A valve fitting having a hole;
A valve mounting structure for a hydraulic cylinder, comprising: a fixing bolt that is inserted into an elongated hole of the valve mounting tool and is screwed into a corresponding screw seat of the hydraulic cylinder.   The valve mounting structure for a hydraulic cylinder according to claim 1, further comprising a protector for covering the pipe breakage control valve, wherein the valve mount includes a protector mounting means to which the protector can be mounted. The hydraulic cylinder valve mounting structure.   3. The hydraulic cylinder valve mounting structure according to claim 1, wherein the screw seats of the hydraulic cylinders are disposed at an outer peripheral portion of the hydraulic cylinder at an angular angle interval of 90 degrees. Mounting structure.   The valve mounting structure for a hydraulic cylinder according to any one of claims 1 to 3, wherein the pipe break control valve is mounted so as to be disposed on the left and right side surfaces of the hydraulic cylinder. Valve mounting structure.

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