The present invention relates to an outrigger equipped on a construction machine, such as a backhoe, to be used for stabilizing work by the machine. Especially, it relates to a structure of a hydraulic cylinder for controlling the vertical movement of the outrigger.
Conventionally, there is a well-known technology about an outrigger equipped on a construction machine, such as a backhoe and a crane, to be used for stabilizing work at a high place.
Normally, the outrigger is provided with a hydraulic cylinder whose telescopic actuation vertically swings the outrigger. The hydraulic cylinder of the outrigger is disposed so that, when the outrigger is lowered to support the vehicle, the hydraulic cylinder is disposed so as to have its cylinder part above its rod part (as disclosed in JP 5-71139A).
The conventional hydraulic cylinder of the outrigger is vertically rotated together with the vertically rotated outrigger, thereby bending a hydraulic pressure hose. Therefore, the hydraulic pressure hose has a length enough to be prevented from being damaged. Still, during the rotation of the cylinder, it happens that the hydraulic pressure hose is bent and rubbed with a nearby frame or another part so as to be damaged.
Moreover, when the outrigger is lowered to support the vehicle, heavy load is applied on the rod part disposed under the cylinder part. Further, dust such as soil easily sticks to the outer peripheral surface of the rod part at this position close to the ground, so as to damage the rod part during telescopic actuation of the hydraulic cylinder, to interfere with the telescopic actuation of the hydraulic cylinder, and to cause oil leak from the hydraulic cylinder.
An object of the invention is to provide a hydraulic cylinder of an outrigger, improved to prevent a hydraulic pressure hose from being damaged, and to prevent a rod part of the hydraulic cylinder from being damaged.
The invention uses the following means for achieving the above object.
According to the invention, a hydraulic cylinder is interposed between a machine frame and each of outriggers, which are vertically swingably disposed at opposite sides of the machine frame, so as to raise and lower the outrigger. A fluid passage is formed in a rod part of the hydraulic cylinder. A connection portion of a fluid suction and delivery port of the fluid passage to be connected to a hydraulic pressure hose is disposed adjacent to a pivot of the hydraulic cylinder.
Further, according to the invention, the hydraulic cylinder is attached to the outrigger so that, when the outrigger is extended outwardly downward, the hydraulic cylinder is disposed so as to have the rod part above its cylinder part.
The invention has the following effects.
According to the invention, a fluid passage is formed in a rod part of the hydraulic cylinder, and a connection portion of a fluid suction and delivery port of the fluid passage to be connected to a hydraulic pressure hose is disposed adjacent to a pivot of the hydraulic cylinder. Therefore, the hydraulic pressure hose can be shortened, and the rod part of the hydraulic cylinder is prevented from being damaged. Further, the hydraulic pressure hose is prevented from being worn when it is extended or folded. Moreover, the hydraulic pressure hose is not exposed to the outside of a frame, thereby being protected from being damaged.
The hydraulic cylinder is attached to the outrigger so that, when the outrigger is extended outwardly downward, the hydraulic cylinder is disposed so as to have the rod part above its cylinder part. Therefore, the rod part of the hydraulic cylinder is prevented from being damaged.
An embodiment of the invention will be described.
Firstly, an entire structure of a backhoe-loader 1 equipped with outriggers 10 according to the invention.
As shown in
As shown in
Backhoe 8 includes a boom 15, an arm 16, and a bucket 17. Boom 15, which is doglegged in side view, is rotatably attached to machine frame 11 through a boom bracket 23. Arm 16 is rotatably attached onto a tip portion of boom 15. Bucket 17 is pivoted onto a tip portion of arm 16 through a linkage 21. A bracket 15a projects from an intermediate rear portion of boom 15. A boom cylinder 25 is interposed between bracket 15a and boom bracket 23, so as to be telescoped for vertically rotating boom 15.
A bracket 16a projects rearward from a basic portion of arm 16. An arm cylinder 26 is interposed between bracket 16a and bracket 15a projecting from boom 15, so as to be telescoped for rotating arm 16 centered on the tip portion of boom 15.
A bucket cylinder 27 is interposed between bracket 16a of arm 16 and linkage 21, so as to be telescoped for rotating bucket 17 centered on the tip portion of arm 16.
Boom cylinder 25, arm cylinder 26 and bucket cylinder 27 are hydraulic cylinders each of which is supplied with fluid through hydraulic pressure pipes and hoses.
A control box 30 is mounted on machine frame 11. Operation levers 31 and 32 for vertically and laterally moving backhoe 8 are extended upward from control box 30. Operation levers 31 and 32 are operated so as to control fluid supply to hydraulic cylinders 25, 26 and 27 for controlling backhoe 8. Operation levers 34 and 35 for controlling respective outriggers 10 are extended rearward from control box 30. Each of operation levers 34 and 35 is operated so as to control a hydraulic cylinder 40 for vertically swinging corresponding outrigger 10.
Backhoe 8 is connected to machine frame 11 through boom bracket 23 laterally rotatably pivoted onto machine frame 11. A pair of left and right hydraulic cylinders 41 are juxtaposed between backhoe 8 and machine frame 11. Backhoe 8 can be tilted leftward or rightward relative to machine frame 11 by alternately telescoping hydraulic cylinders 41.
Due to the above structure of backhoe-loader 1, during traveling of backhoe-loader 1, operator's seat 6 is faced forward, and steering wheel 5 is operable for steering the vehicle body. To operate front loader 7, an operator sitting on seat 6, which is still faced forward (during forward traveling), controls operation levers in the operator's room.
To operate backhoe 8 and outriggers 10 disposed at the rear portion of the body, operator's seat 6 is exactly rotatably reversed so as to control the operation levers projecting from the control box at the rear portion of the body.
A structure of the outriggers will be detailed.
As shown in
Outriggers 10 are provided with respective telescopically movable hydraulic cylinders 40. The telescopic movements of hydraulic cylinders 40 are controlled so as to swing respective outriggers 10 upward or downward. Left and right brackets 13 project leftward and rightward from machine frame 11, and each of outriggers 10 is pivoted onto each of brackets 13, so as to be rotatably attached to machine frame 11.
An earthed plate 12 is pivoted on the earthed tip of each of outriggers 10, so as to be rotated to face its bottom surface downward during the vertical swing of outrigger 10. Hydraulic cylinders 40 are attached to respective outriggers 10 so that, when left and right outriggers 10 are lowered, i.e., extended downward in lateral opposite directions, hydraulic cylinders 40 are disposed on the upper sides of respective outriggers 10 (contrarily, when outriggers 10 are raised to be folded, hydraulic cylinders 40 are disposed laterally inward of respective outriggers 10), and each of hydraulic cylinders 40 extended to lower respective outriggers 10 has its rod part 40b disposed above its cylinder part 40a.
When outriggers 10 are lowered, i.e., extended downward in lateral opposite directions, a pair of projections 10a project upward from the earthed tip portion of each of outriggers 10, a tip (lower end on the head side) of cylinder part 40a of hydraulic cylinder 40 is pivoted on a pin 45 between the pair of projections 40a, and a tip (upper end) of rod part 40b, i.e., the other end of hydraulic cylinder 40, is pivoted on a pin 46 disposed at an upper portion of each of brackets 13 projecting from machine frame 11.
As shown in
Hydraulic pressure pipes 50a and 50b are made of steel pipes or the like. As shown in
As shown in
Due to the above structure of hydraulic cylinders 40 of the outriggers, when an operator operates the operation levers for extending hydraulic cylinders 40 having been contracted, earthed plates 12 and outriggers 10 are rotated outwardly downward from machine frame 11, and earthed plates 12 are pressed down against the ground, so that outriggers 10 are stretched to support the body.
Whether the hydraulic cylinders of the outriggers are contracted or extended, the change of distance between machine frame 11 and each of hydraulic pressure pipes 50a and 50b is small so as to reduce the bends of hydraulic pressure hoses 51a and 51b.
As mentioned above, each of hydraulic cylinders 40 has proximal rod part 40b and distal cylinder part 40a with respect to the body. In other words, when each of outriggers 10 is extended outwardly downward from the body, its hydraulic cylinder 40 is disposed so as to have rod part 40b above cylinder part 40a. Therefore, upper rod part 40b is disposed at a distance from the ground surface so as to hardly have soil, sand or the like stuck thereon, thereby reducing damage to the outer peripheral portion of rod part 40b during the telescopic actuation of the hydraulic cylinder.
Fluid passages 54a and 54b are formed within rod part 40b of each of hydraulic cylinders 40 in parallel to each other along the axis of rod part 40b. Portions of connecting the end ports (for suction and delivery of fluid) of fluid passages 54a and 54b to respective hydraulic pressure hoses 51a and 51b are disposed adjacent to the pivot for rotating hydraulic cylinder 40. Conventionally, the pipes are extended to the cylinder part so as to have a surplus length such as to moderate bends thereof during the rotation of the hydraulic cylinder. Contrarily, the present hydraulic pressure hoses, whose tips are disposed adjacent to the pivot, have almost constant distances from the machine frame even while the hydraulic cylinder is telescoped. Thus, the hydraulic pressure hoses do not have the surplus length for moderating bends thereof, thereby being shortened. Further, since the hydraulic pressure pipes and hoses are disposed at the tip of the rod part close to the machine frame, the hydraulic pressure pipes have almost no part exposed to the outside of the body, thereby being prevented from being damaged by an external obstacle.
The hydraulic cylinder of an outrigger according to the present invention is industrially applicable, which is used for not only the above-mentioned construction machines such as a backhoe but also transportation machines such as a truck, and other machines.
Number | Date | Country | Kind |
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2004-209399 | Jul 2004 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP04/13452 | 9/15/2005 | WO | 6/7/2007 |