JP5789158B2 - Cylinder equipment for construction machinery - Google Patents

Description

  The present invention relates to a cylinder device for a construction machine used for driving a working device such as a hydraulic excavator or a wheel loader.

  In general, a hydraulic excavator as a representative example of a construction machine is a crawler type lower traveling body that can be self-propelled, an upper revolving body that is turnably mounted on the lower traveling body, and a front side of the upper revolving body. It is roughly constituted by a working device provided so as to be able to move up and down. And a hydraulic excavator performs excavation work of earth and sand, etc. using a working device, turning an upper revolving structure.

  The working device of the hydraulic excavator is provided with a boom that can be moved up and down on the upper swing body, an arm that can be pivoted on the tip side of the boom, and a pivot that can be pivoted on the tip side of the arm. The boom, the arm, and the work tool are each driven by a cylinder device including a hydraulic cylinder or the like.

On the other hand, a crane-type hydraulic excavator is known in which a hook for a suspended load is provided at the tip of the working device and a crane operation (suspended load operation) for lifting a relatively light load can be performed using this hook. Yes. Here, the cylinder device used for the working device of the crane-type hydraulic excavator is usually a hydraulic cylinder having a tube and a rod , and a hydraulic conduit connected to the hydraulic cylinder for supplying and discharging pressure oil for cylinder expansion and contraction. A pressure sensor that is connected to the hydraulic pipe line via a joint and detects the pressure in the hydraulic cylinder, and a sensor cover that protects the pressure sensor are configured (for example, Patent Document 1).

  Here, for example, when the load is lifted using a hook during crane operation, the pressure sensor determines whether the load of the suspended load is excessive, so that the rod side oil chamber, the bottom side oil chamber of the boom cylinder Or the like. The pressure sensor detects whether or not the hydraulic hose for supplying and discharging the pressure oil to the rod side oil chamber and the bottom side oil chamber of the boom cylinder is broken. In this case, the pressure sensor, which is an electrical component, is damaged by receiving an external force, and thus is protected while being surrounded by the sensor cover.

Japanese Patent Laid-Open No. 2005-42867

  However, in the above-described conventional technology, a mounting seat is provided on a hydraulic pipe formed using a steel pipe or the like, and a sensor cover is attached to the mounting seat. For this reason, when the excavator performs excavation work or the like, when earth or sand collides with the sensor cover, the external force (impact) acting on the sensor cover is directly transmitted to the hydraulic pipe line via the mounting seat. Will be. As a result, there is a problem that the hydraulic pipe is damaged or broken, and the durability of the hydraulic pipe is lowered.

  The present invention has been made in view of the above-described problems of the prior art, so that the external force acting on the sensor cover can be prevented from being directly transmitted to the hydraulic pipeline, and the durability of the hydraulic pipeline can be improved. An object of the present invention is to provide a cylinder device for a construction machine.

  In order to solve the above-mentioned problems, the present invention is used to drive a working device of a construction machine, and includes a hydraulic cylinder having a tube and a rod provided to be extendable / contractible to the tube, and connected to the hydraulic cylinder. A hydraulic pipe for supplying and discharging pressure oil for cylinder expansion and contraction; a pressure sensor connected to the hydraulic pipe via a joint for detecting pressure in the hydraulic cylinder; and a sensor cover for protecting the pressure sensor It is applied to the cylinder device of construction machinery.

The invention according to claim 1 is characterized in that a mounting seat for mounting the hydraulic conduit is fixedly provided on a tube of the hydraulic cylinder, and the hydraulic conduit is disposed in a vicinity of the joint, In order to fix the hydraulic pipe line to the tube of the hydraulic cylinder, a bracket made of a plate material having one side fixed to the hydraulic pipe line and the other side being a flat mounting plane is provided, and the sensor cover is a mounting plane of the bracket And a mounting surface that extends from the mounting surface and covers the pressure sensor from the outer peripheral side, and the mounting surface of the bracket and the mounting surface of the sensor cover include a fastening member. In other words, the mounting seat is fastened together.

The invention of claim 2, a female screw hole provided in the mounting seat, said fastening member, the bolt insertion hole formed in the mounting surface of the bolt insertion hole and the sensor cover provided on the mounting plane of the bracket It is constituted by a fixing bolt that is inserted and screwed into the female screw hole, the mounting surface of the sensor cover is provided with another bolt insertion hole adjacent to the fixing bolt, and the mounting plane of the bracket has the above-mentioned Another bolt insertion hole is provided adjacent to the fixing bolt, and the sensor cover is prevented from rotating with respect to the bracket using a locking bolt inserted into each of the bolt insertion holes. .

According to the present invention, the mounting seat provided fixed to the hydraulic cylinder tube to, be fastened with a fastening member and a sensor cover protecting the brackets and pressure sensor fixed to the hydraulic line Thus, the hydraulic pipe line can be attached to the attachment seat via the bracket, and the sensor cover can be attached to the attachment seat. As a result, even when earth or sand collides with the sensor cover during excavation work using the working device, it is possible to suppress the external force (impact) acting on the sensor cover from being directly transmitted to the hydraulic pipe line via the bracket, An external force acting on the sensor cover can be received mainly by the mounting seat. As a result, damage, breakage, etc. of the hydraulic pipe line can be suppressed, and its durability can be enhanced.

According to the second aspect of the present invention, the hydraulic line and the sensor cover can be joined together by simply screwing the fixing bolt inserted into the bolt insertion hole of the sensor cover and the bolt insertion hole of the bracket into the female screw hole of the mounting seat. Can be attached to the mounting seat. In addition, a locking bolt provided in the vicinity of the fixing bolt, another bolt insertion hole provided in the mounting surface of the sensor cover adjacent to the fixing bolt, and the bracket adjacent to the fixing bolt. The sensor cover can be properly positioned with respect to the pressure sensor by inserting it into another bolt insertion hole provided on the mounting plane of the sensor, and the sensor cover can be properly positioned. Can be reliably protected.

It is a front view which shows the hydraulic shovel provided with the cylinder apparatus by embodiment of this invention. It is a principal part enlarged view which shows the boom in FIG. 1, a boom cylinder, a hydraulic pipe line, a pressure sensor, a T joint, a sensor cover, etc. FIG. 3 is an enlarged view of a main part of a boom, a boom cylinder, a hydraulic line, a fall prevention valve, and the like when viewed from the back side of FIG. It is a front view which shows a boom cylinder independently. It is a perspective view which shows the assembly | attachment states, such as a boom cylinder, a mounting seat, a hydraulic pipe line, a bracket, a T joint, a pressure sensor, and a sensor cover. It is a disassembled perspective view which shows a hydraulic pipe line, a bracket, a T joint, a pressure sensor, etc. It is a disassembled perspective view which shows the state which fastens a bracket and a sensor cover together with a bolt with respect to the mounting seat of a boom cylinder. It is a perspective view which shows the assembly | attachment states of T joint etc. which removed the boom cylinder, the mounting seat, the hydraulic pipe line, the bracket, and the pressure sensor. It is a disassembled perspective view which shows the state which attaches a bracket with respect to the mounting seat of a boom cylinder using a volt | bolt. It is a disassembled perspective view similar to FIG. 7 which shows the modification of a mounting seat. It is a disassembled perspective view similar to FIG. 6 which shows the modification of a bracket.

  Hereinafter, a cylinder device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings, taking as an example the case of applying to a boom cylinder of a crane-type hydraulic excavator. In the present embodiment, the pressure sensor detects the pressure of the boom-side oil chamber of the boom cylinder, but the pressure of the boom-side oil chamber of the boom cylinder may be detected. On the other hand, it may be applied not only to a boom cylinder but also to an arm cylinder and a bucket cylinder.

  In the figure, reference numeral 1 denotes a hydraulic excavator as a typical example of a construction machine. The hydraulic excavator 1 is a self-propelled crawler-type lower traveling body 2 and an upper portion mounted on the lower traveling body 2 so as to be able to turn. The revolving unit 3 and a swing type working device 4 provided on the front side of the upper revolving unit 3 are roughly configured, and the working device 4 performs excavation work of earth and sand. In addition, a hanging hook (not shown) is stored on the distal end side of the working device 4, and a crane work for lifting a load using this hook can be performed.

  Here, the swing type working device 4 includes a swing post 5 attached to a front end side of a swing frame 3A that is a base of the upper swing body 3 so as to be swingable leftward and rightward, and an upper end portion of the swing post 5. The boom 6 is pivotably mounted in the upward and downward directions, the arm 7 is pivotally mounted on the distal end side of the boom 6, and the upper and lower portions are disposed on the distal end side of the arm 7. A bucket 8 that is rotatably attached in the direction, a boom cylinder 12 that drives the boom 6, an arm cylinder 9 that drives the arm 7, and a bucket cylinder 10 that drives the bucket 8 are roughly configured. .

  Then, the working device 4 rotates the boom 6, the arm 7 and the bucket 8 in a state where the swing post 5 is swung left and right by a swing cylinder (not shown), so that the side groove on the side of the road. Excavation work such as.

  Next, as a representative example of the cylinder device used in the present embodiment, a boom cylinder will be described as an example.

  That is, 11 indicates a cylinder device according to the present embodiment, and the cylinder device 11 is used to drive the boom 6. The cylinder device 11 includes a boom cylinder 12, a mounting seat 13, a rod side hydraulic pipe 18, a bracket 21, a T joint 20, a pressure sensor 22, a sensor cover 23, a fixing bolt 24, a locking bolt 25, and the like, which will be described later. It is configured.

  Reference numeral 12 denotes a boom cylinder as a hydraulic cylinder provided between the swing post 5 and the boom 6. As shown in FIGS. 2 to 4, the boom cylinder 12 includes a cylindrical tube 12 </ b> A, The piston 12B is slidably inserted into the tube 12A, and a rod 12C having a proximal end fixed to the piston 12B and a distal end protruding from the tube 12A. The inside of the tube 12A is defined by a piston 12B into a rod-side oil chamber 12D and a bottom-side oil chamber 12E, and the rod 12C expands and contracts according to the supply and discharge of pressure oil to and from the rod-side oil chamber 12D and the bottom-side oil chamber 12E. It is the composition to do.

  Also, a bottom side mounting eye (clevis) 12F is integrally provided on the bottom side of the tube 12A, and this bottom side mounting eye 12F is pin-coupled to the front end portion of the swing post 5 so as to be rotatable upward and downward. Has been. On the other hand, a rod side mounting eye (clevis) 12G is integrally provided at the tip of the rod 12C, and this rod side mounting eye 12G is directed upward and downward to a cylinder mounting plate 6A provided at an intermediate portion of the boom 6. Is pivotally connected to the pin.

  Reference numeral 13 denotes a mounting seat provided on the tube 12A of the boom cylinder 12, and the mounting seat 13 is for mounting a bracket 21, a sensor cover 23 and the like which will be described later. Here, as shown in FIG. 7, the mounting seat 13 is formed in a short cylindrical shape, and one female screw hole 13 </ b> A is screwed at the center thereof. The mounting seat 13 is fixed to the outer peripheral surface of the tube 12A using means such as welding.

  Reference numeral 14 denotes a fall prevention valve which is located on the opposite side of the mounting seat 13 and is attached to the tube 12A of the boom cylinder 12. As shown in FIG. 3, the fall prevention valve 14 is attached to the tube 12 </ b> A via a valve attachment plate 15, and is connected to a bottom hydraulic line 16, a bottom hydraulic hose 17 and the like which will be described later. The fall prevention valve 14 is used when, for example, a bottom hydraulic hose 17 (described later) that supplies and discharges pressure oil to the boom cylinder 12 is damaged and oil leakage occurs during excavation work using the working device 4. By holding the boom cylinder 12 in an oil-locked state, the tip end side of the boom 6 is prevented from dropping downward.

  Reference numeral 16 denotes a bottom side hydraulic pipe line fixed to the tube 12 </ b> A of the boom cylinder 12, and the bottom side hydraulic pipe line 16 is provided between the bottom side oil chamber 12 </ b> E of the boom cylinder 12 and the fall prevention valve 14. To connect. Here, the bottom side hydraulic pipe line 16 is formed using a pipe material such as a steel pipe, and one end side 16A is connected to the fall prevention valve 14 and the other end side 16B is connected to the bottom side oil chamber 12E. Thus, the tube 12A is fixedly disposed on the outer peripheral surface.

  Reference numeral 17 denotes a bottom hydraulic hose connected to the fall prevention valve 14, and the bottom hydraulic hose 17 connects a hydraulic source (not shown) mounted on the upper swing body 3 and the fall prevention valve 14. To do. Here, the bottom side hydraulic hose 17 is formed using a flexible rubber hose or the like. The bottom side hydraulic hose 17 supplies pressure oil from a hydraulic pump (not shown) mounted on the upper swing body 3 to the bottom of the boom cylinder 12 via the fall prevention valve 14, the bottom side hydraulic line 16, and the like. While supplying to the side oil chamber 12E, the hydraulic oil in the bottom side oil chamber 12E is supplied to a tank (not shown) mounted on the upper swing body 3 via the bottom side hydraulic line 16, the fall prevention valve 14, and the like. To be discharged.

  Next, reference numeral 18 denotes a rod side hydraulic pipe line fixedly provided on the tube 12A of the boom cylinder 12. The rod side hydraulic pipe line 18 is connected to a hydraulic power source (not shown) mounted on the upper swing body 3 via a T joint 20 and a rod side hydraulic hose 19 which will be described later. Here, the rod side hydraulic pipe line 18 is formed using a pipe material such as a steel pipe, and one end side 18A is fixed to the mounting seat 13 of the boom cylinder 12 via a bracket 21 described later, and the other end side 18B. Is fixedly disposed on the outer peripheral surface of the tube 12A by being connected to the rod side oil chamber 12D.

  Reference numeral 19 denotes a rod-side hydraulic hose connected to one end side 18A of the rod-side hydraulic line 18 via a T joint 20 which will be described later. The rod-side hydraulic hose 19 includes a hydraulic source mounted on the upper swing body 3 and The rod-side hydraulic pipe line 18 is connected. Here, the rod side hydraulic hose 19 is formed using a flexible rubber hose or the like. The rod-side hydraulic hose 19 sends pressure oil from a hydraulic pump (not shown) mounted on the upper swing body 3 to the rod side of the boom cylinder 12 via the T joint 20, the rod-side hydraulic line 18 and the like. While supplying to the oil chamber 12D, the hydraulic oil in the rod-side oil chamber 12D is discharged to a tank (not shown) mounted on the upper swing body 3 through the rod-side hydraulic line 18, the T joint 20, and the like. Is.

  Reference numeral 20 denotes a T joint (Chi) as a joint connected to one end side 18 </ b> A of the rod side hydraulic pipe 18. This T joint 20 is formed of a T-shaped tube body provided with three connection ports, and connects between one end side 18A of the rod side hydraulic pipe 18 and the rod side hydraulic hose 19, and will be described later. A pressure sensor 22 is attached.

  Next, reference numeral 21 denotes a bracket provided fixed to one end side 18A of the rod side hydraulic pipe line 18. As shown in FIG. 6, the bracket 21 is formed by bending a rectangular plate material, for example, and has a concave curved surface curved in a concave arc shape with a curvature substantially equal to the outer peripheral surface of the rod side hydraulic pipe 18. 21A and a flat mounting plane 21B continuous to the concave curved surface 21A. Two bolt insertion holes 21C and 21D are formed in the mounting plane 21B, a fixing bolt 24 described later is inserted into one bolt insertion hole 21C, and a rotation stop described later is inserted into the other bolt insertion hole 21D. The construction bolt 25 is inserted.

  Then, the concave curved surface 21A of the bracket 21 is fitted to the one end side 18A of the rod side hydraulic pipe line 18 at a position near the T joint 20, and a means such as welding is used for the rod side hydraulic pipe line 18. It is firmly fixed. Therefore, the rod-side hydraulic pipe is inserted by inserting a fixing bolt 24 described later into the bolt insertion hole 21C of the bracket 21 and screwing the fixing bolt 24 into the female screw hole 13A provided in the mounting seat 13 of the boom cylinder 12. One end side 18 </ b> A of the path 18 can be fixed to the tube 12 </ b> A of the boom cylinder 12.

  Reference numeral 22 denotes a pressure sensor attached to the T joint 20. This pressure sensor 22 is connected to the rod side hydraulic pipe line 18 via the T joint 20 and detects the pressure in the rod side oil chamber 12D of the boom cylinder 12. Here, when a crane operation for lifting a load using the working device 4 of the hydraulic excavator 1 is performed, the load of the suspended load is based on the pressure in the rod side oil chamber 12D detected by the pressure sensor 22, for example. It can be determined whether or not is excessive. On the other hand, the pressure sensor 22 is also used to detect whether or not the rod-side hydraulic hose 19 for supplying and discharging pressure oil to the rod-side oil chamber 12D of the boom cylinder 12 is damaged.

  Reference numeral 23 denotes a sensor cover that covers the pressure sensor 22 attached to the T joint 20. As shown in FIG. 7, the sensor cover 23 is formed by bending a rectangular plate material, for example, and is attached to the mounting surface 23A that contacts the mounting plane 21B of the bracket 21 and the mounting surface 23A. The cover surface 23B is bent into a U-shaped cross section and covers the pressure sensor 22 so as to surround the outer periphery. In addition, two bolt insertion holes 23C and 23D corresponding to the bolt insertion holes 21C and 21D of the bracket 21 are formed in the mounting surface 23A.

  Reference numeral 24 denotes a fixing bolt as a fastening member. The fixing bolt 24 fastens the bracket 21 and the sensor cover 23 fixed to the rod side hydraulic pipe 18 to the mounting seat 13 of the boom cylinder 12 together. It is to be fixed. That is, as shown in FIG. 7, the fixing bolt 24 is inserted into the tube 12 </ b> A of the boom cylinder 12 with the bolt 24 inserted into one bolt insertion hole 23 </ b> C of the sensor cover 23 and the one bolt insertion hole 21 </ b> C of the bracket 21. The bracket 21 and the sensor cover 23 can be firmly fixed to the mounting seat 13 by being screwed into the female screw hole 13 </ b> A of the fixed mounting seat 13.

  In this case, the rod-side hydraulic pipe line 18 has a bracket 21 fixed to one end side 18 </ b> A fixed to the mounting seat 13 by a fixing bolt 24, and the other end side 18 </ b> B connected to the rod-side oil chamber 12 </ b> D of the boom cylinder 12. By doing so, the tube 12A is fixed to the outer peripheral surface of the tube 12A in a supported state.

  Reference numeral 25 denotes a locking bolt provided in the vicinity of the fixing bolt 24, and the locking bolt 25 locks the sensor cover 23 relative to the bracket 21. That is, as shown in FIG. 7, the nut 26 is screwed in a state where the locking bolt 25 is inserted into the other bolt insertion hole 23D of the sensor cover 23 and the other bolt insertion hole 21D of the bracket 21. As a result, the sensor cover 23 is fixed to the bracket 21.

  As a result, the rotation of the sensor cover 23 around the fixing bolt 24 can be restricted by the locking bolt 25, and the sensor for the pressure sensor 22 attached to the T joint 20 as shown in FIG. The cover 23 can be properly positioned.

  When the pressure sensor 22 is not mounted, the connection port is sealed by attaching a plug 27 to the connection port of the T joint 20 to which the pressure sensor 22 is attached, as shown in FIGS. To do.

  In this case, since the sensor cover 23 that protects the pressure sensor 22 is not necessary, the fixing bolt 24 is inserted only into the bolt insertion hole 21 </ b> C of the bracket 21 that is fixed to the rod side hydraulic pipe 18. Then, the fixing bolt 24 is screwed into the female screw hole 13 </ b> A of the mounting seat 13 fixed to the boom cylinder 12, whereby the one end side 18 </ b> A of the rod side hydraulic pipe line 18 can be fixed to the mounting seat 13.

  As described above, when the pressure sensor 22 is not mounted, only the sensor cover 23, the locking bolt 25, and the nut 26 are not necessary, and the bracket 21 and the fixing bolt 24 are not related to the presence or absence of the pressure sensor 22. Therefore, it can be used as a common part.

  The cylinder device 11 according to the present embodiment has the above-described configuration, and the procedure for assembling the cylinder device 11 will be described below.

  First, as shown in FIG. 6, the concave curved surface 21 </ b> A of the bracket 21 is welded to one end side 18 </ b> A of the rod-side hydraulic pipe 18, so that the bracket 21 is placed in the vicinity of the T joint 20 in the rod-side hydraulic pipe 18. Is fixed. On the other hand, the rod side hydraulic pipe 18 and the rod side hydraulic hose 19 are connected by a T joint 20, and a pressure sensor 22 is attached to the T joint 20.

  Next, as shown in FIG. 7, a fixing bolt 24 is inserted into the bolt insertion hole 23C of the sensor cover 23 and the bolt insertion hole 21C of the bracket 21, and the fixing bolt 24 is inserted into the tube 12A of the boom cylinder 12. It is screwed into the female screw hole 13A of the fixed mounting seat 13. Accordingly, the bracket 21 and the sensor cover 23 can be fastened together with the mounting seat 13 using the fixing bolt 24, and the mounting seat 13 for fixing the one end side 18 </ b> A of the rod side hydraulic pipe 18 is used. Thus, the sensor cover 23 can be firmly fixed.

  In this state, the locking bolt 25 is inserted into the bolt insertion hole 23D of the sensor cover 23 and the bolt insertion hole 21D of the bracket 21, and the nut 26 is screwed onto the locking bolt 25. Thereby, the sensor cover 23 is fixed to the bracket 21, and the rotation of the sensor cover 23 around the fixing bolt 24 can be restricted by the locking bolt 25.

  As a result, as shown in FIG. 5, one end side 18 </ b> A of the rod side hydraulic pipe 18 is firmly fixed to the mounting seat 13 of the boom cylinder 12 via the bracket 21 and the pressure sensor attached to the T joint 20. The sensor cover 23 covering 22 can be firmly fixed using the mounting seat 13. In this case, since the sensor cover 23 is stopped with respect to the bracket 21 by the locking bolt 25, the sensor cover 23 can be properly positioned with respect to the pressure sensor 22, and the pressure sensor 22 can be positioned by the sensor cover 23. Can be reliably protected.

  In the hydraulic excavator 1 including the cylinder device 11 as described above, earth and sand fall from the bucket 8 during excavation work using the working device 4, and the fallen earth and sand collides with the sensor cover 23. A large external force acts on 23.

  On the other hand, in the present embodiment, the bracket 21 and the sensor cover 23 fixed to the one end side 18A of the rod side hydraulic pipe 18 are fixed to the mounting seat 13 fixed to the tube 12A of the boom cylinder 12 with the fixing bolt. The sensor cover 23 can be firmly fixed to the mounting seat 13 by tightening together with 24. Thereby, even if earth or sand collides with the sensor cover 23, an external force acting on the sensor cover 23 can be received mainly by the mounting seat 13. As a result, it is possible to suppress external force acting on the sensor cover 23 from being directly transmitted to the rod side hydraulic pipe line 18 and to prevent damage or breakage of the rod side hydraulic pipe line 18. The durability of the pipe line 18 can be increased.

  Furthermore, the sensor cover 23 is always fixed at an appropriate position with respect to the pressure sensor 22 by stopping the sensor cover 23 with respect to the bracket 21 by a locking bolt 25 provided in the vicinity of the fixing bolt 24. can do. As a result, the pressure sensor 22 can be reliably protected by the sensor cover 23, and the reliability of the pressure sensor 22 can be improved.

  In the above-described embodiment, one fixing bolt 24 inserted into one bolt insertion hole 21C of the bracket 21 and one bolt insertion hole 23C of the sensor cover 23 is inserted into the female screw hole 13A of the mounting seat 13. By screwing, the bracket 21 and the sensor cover 23 are fixed to the mounting seat 13, and one turn inserted through the other bolt insertion hole 21 </ b> D of the bracket 21 and the other bolt insertion hole 23 </ b> D of the sensor cover 23. The nut 26 is screwed onto the fixing bolt 25 so that the sensor cover 23 is prevented from rotating with respect to the bracket 21.

  However, the present invention is not limited to this. For example, as in the modification shown in FIG. 10, the mounting seat 31 having two female screw holes 31 </ b> A is fixedly provided on the tube 12 </ b> A of the boom cylinder 12. The bracket 21 and the sensor cover 23 may be fastened together with the mounting seat 31 using the two fixing bolts 24 screwed into the female screw hole 31A.

  In the above-described embodiment, the bracket 21 fixed to the rod-side hydraulic pipe 18 is provided with a concave curved surface 21A, and the concave curved surface 21A is fitted to the rod-side hydraulic pipe 18 in a means such as welding. The case where it fixes using is illustrated. However, the present invention is not limited to this. For example, as in the second modified example shown in FIG. 11, a short rectangular bracket 32 having two bolt insertion holes 32A and 32B is used. It is good also as a structure which welds the edge part of 32 to the outer peripheral surface of the rod side hydraulic pipe 18.

  In the above-described embodiment, the cylinder device 11 including the pressure sensor 22 that detects the pressure in the rod-side oil chamber 12D of the boom cylinder 12 and the sensor cover 23 that protects the pressure sensor 22 is taken as an example. Although described above, the present invention is not limited to this, and can be applied to a cylinder device including a pressure sensor for detecting the pressure in the bottom side oil chamber 12E of the boom cylinder 12 and a sensor cover for protecting the pressure sensor. it can.

  Furthermore, in embodiment mentioned above, the cylinder apparatus 11 containing the boom cylinder 12 of the hydraulic shovel 1 is illustrated. However, the present invention is not limited to this, and can be applied to a cylinder device including an arm cylinder 9, a bucket cylinder 10, and a swing cylinder (not shown) that drive the working device 4 of the excavator 1, for example.

1 Excavator (construction machine)
4 Working device 11 Cylinder device 12 Boom cylinder (hydraulic cylinder)
12A tube 12C rod 13, 31 mounting seat 13A, 31A female screw hole 18 rod side hydraulic line (hydraulic line)
20 T Fitting (Fitting)
21, 32 Bracket 22 Pressure sensor 23 Sensor cover 24 Fixing bolt (fastening member)
25 Locking bolt

Claims (2)

A hydraulic cylinder that is used to drive a working device of a construction machine and has a tube and a rod that can be expanded and contracted with respect to the tube, and a hydraulic pressure that is connected to the hydraulic cylinder and supplies and discharges pressure oil for expanding and contracting the cylinder In a cylinder device of a construction machine, comprising: a pipe line; a pressure sensor connected to the hydraulic pipe line via a joint for detecting pressure in the hydraulic cylinder; and a sensor cover for protecting the pressure sensor.
The tube of the hydraulic cylinder is fixedly provided with a mounting seat for mounting the hydraulic conduit,
The hydraulic pipe is disposed in the vicinity of the joint, and one side is fixed to the hydraulic pipe to fix the hydraulic pipe to the tube of the hydraulic cylinder, and the other side is a flat mounting plane. Provide a bracket made of plate material,
The sensor cover has a mounting surface that contacts the mounting plane of the bracket, and a cover surface that is formed to extend from the mounting surface and covers the pressure sensor from the outer peripheral side,
A cylinder device for a construction machine, wherein the mounting surface of the bracket and the mounting surface of the sensor cover are fastened to the mounting seat using a fastening member.   The mounting seat is provided with a female screw hole, and the fastening member is inserted into a bolt insertion hole provided in a mounting plane of the bracket and a bolt insertion hole provided in a mounting surface of the sensor cover, and is screwed into the female screw hole. The mounting surface of the sensor cover is provided with another bolt insertion hole adjacent to the fixing bolt, and the mounting surface of the bracket is adjacent to the fixing bolt. 2. The construction machine cylinder according to claim 1, wherein another bolt insertion hole is provided, and the sensor cover is prevented from rotating with respect to the bracket using a locking bolt inserted into each of the bolt insertion holes. apparatus.

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