JPH09302705A - Arranging method for oil-hydraulic cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make smooth movement possible for an arm by a method wherein oil-hydraulic cylinders are provided respectively at the back side and the belly side of a front boom, and a supply/discharge circuit for pressure oil is formed through both of the cylinders. SOLUTION: Oil-hydraulic cylinders 30 and 31 are provided respectively at the back side and the belly side of a front boom 26 of a hydraulic power shovel. A bottom-side oil chamber 45 of the backside oil-hydraulic cylinder 30 is made to communicate with a rod-side oil chamber 46 of the belly-side oil-hydraulic cylinder 31 through pipe lines 47 and 48 while a rod-side oil chamber 50 of the back-side oil-hydraulic cylinder 30 is made to communicate with a bottom-side oil chamber 51 of the belly-side oil-hydraulic cylinder 31 through pipe lines 52 and 53, and thereby a pressure oil supply/discharge circuit communicating with both of the oil-hydraulic cylinders 30 and 31 is formed. Therefore, both of the oil-hydraulic cylinders 30 and 31 can be operated smoothly, making an arm 27 swing smoothly without troubles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a construction machine such as a hydraulic excavator, a boom, an arm and a work tool which are sequentially connected to the front part of a work vehicle so as to be rotatable in the front-rear direction, and the arm is bent with respect to the boom. The present invention relates to a method of disposing a hydraulic cylinder that is driven.

[0002]

2. Description of the Related Art FIG. 4 is a side view of a hydraulic excavator 2 equipped with a front attachment 1 for a backhoe described in Japanese Utility Model Publication No. 7-52184. In the hydraulic excavator 2 shown in FIG. 4, the main boom 3 for a long attachment is attached to the front portion thereof, and the rear end portion B of the front boom 4 is fixed to the tip portion a of the main boom 3 by means of a plurality of pins or the like. ing. A base end boss 7 of a backhoe arm 6 is pivotally attached to the front end 5 of the front boom 4, and a rear bracket 8 of the arm 6 is provided.
Both ends of the arm cylinder 10 are pivotally mounted between the front boom 4 and a bracket 9 fixed to the back of the upper surface of the front boom 4, and the arm 6 is extended and retracted by the expansion and contraction operation of the arm cylinder 10. There is. Therefore, when the hydraulic excavator 2 performs the crushing work, only the main boom 3 is left on the front part of the vehicle body, the other front attachment constituent members are removed, and the long attachment for the crushing device (not shown) is replaced.

Next, FIG. 5 is a side view of a hydraulic excavator 12 equipped with a work attachment 11 described in Japanese Utility Model Laid-Open No. 7-23047. In the work attachment 11 shown in FIG. 5, the main boom 13 and the front boom 14 are connected via an adapter 15 to form a so-called split type boom 16, and the front end of the front boom 14 has a rear end of an arm 17. The base is connected and its arm 1
A crusher 18 for dismantling the foundation is attached to the tip of 7. And a ventral surface side bracket 19 at the rear of the arm 17,
An arm cylinder 21 is connected between the front boom 14 and the abdominal surface side bracket 20. Then, the arm cylinder 21 is actuated to move the arm 17 to the front boom 14.
On the other hand, it is designed to rotate up and down. By using the crusher 18 for dismantling the foundation, it is possible to crush a low-rise foundation structure such as a building. When the crushing work is not performed, the crushing machine for basic dismantling 18 can be replaced with a work tool such as a bucket to perform excavation work other than the crushing work.

[0004]

The work attachment 11 of the hydraulic excavator 12 shown in FIG. 5 is provided with a crusher 18 for dismantling the basic body, but since the crusher 18 for dismantling the basic body is heavy, it is held. Due to the capability of the hydraulic cylinder, the arm cylinder 21 is attached to the ventral side of the front boom 14, the cylinder tube base end 22 of the arm cylinder 21 is attached to the ventral side bracket 20 of the front boom 14, and the rod tip 23 is attached to the arm 17. The rear abdominal surface side brackets 19 are pivotally connected to each other. However, there is a case where it is desired to attach a heavier crusher due to the convenience of the hydraulic excavator 12. In order to deal with such a case, a means for allowing a large-diameter arm cylinder to be taken into consideration is considered, but it is economically unsatisfactory because the manufacturing cost of the large-diameter arm cylinder is very high. Further, a plurality of arm cylinders having a relatively small diameter are arranged side by side on the ventral side of the front boom 14, but the lateral width of the front boom 14 and the arm 17 is limited, and a sufficient supporting force is secured. Was difficult. The present invention provides at least a single hydraulic cylinder on each of the ventral side and the rear side of the boom, and exerts sufficient supporting force to hold a work tool / device such as a heavy crusher. An object of the present invention is to provide a method for disposing hydraulic cylinders that enables smooth operation of the hydraulic cylinders on the abdominal surface side and the rear surface side.

[0005]

According to the present invention, a boom, an arm and a work tool are sequentially connected to a front portion of a vehicle body so as to be rotatable in the front-rear direction, and the arm is bent and driven with respect to the boom. In a construction machine, a work vehicle, etc., a bracket for connecting each one end of the hydraulic cylinder is fixedly mounted on the back surface and the ventral surface of the boom, and the hydraulic cylinder is mounted on the rear surface and the ventral surface on the rear side of the arm. A bracket for connecting the other ends of the boom is fixed, a boom rear side hydraulic cylinder is provided between the boom rear side bracket and the arm rear side bracket, and the boom front side A boom rear side hydraulic cylinder is installed between the bracket and the boom front side hydraulic cylinder between the boom front side bracket and the arm front side bracket. It was to be interposed.

Further, according to the present invention, a directional switching valve for switching and controlling the boom back side hydraulic cylinder and the boom back side hydraulic cylinder serves as a pressure oil supply / discharge circuit communicating with both of the hydraulic cylinders so that the bottom side oil of the boom back side hydraulic cylinder is used. Chamber and the rod side oil chamber of the boom abdominal surface side hydraulic cylinder to communicate with each other to form one side circuit of the pressure oil supply / discharge circuit, and the rod side oil chamber of the boom rear side hydraulic cylinder and the boom abdominal surface hydraulic pressure. The bottom side oil chamber of the cylinder is connected to form the other side circuit of the pressure oil supply / discharge circuit.

According to the present invention, at least a single hydraulic cylinder is provided on each of the back side and the ventral side of the boom, so that sufficient supporting force for holding a work tool or device such as a heavy crusher is exerted. be able to. Further, according to the present invention, when the main pressure oil is supplied and circulated to one circuit of the pressure oil supply / discharge circuit from the direction switching valve for controlling the switching between the boom rear side hydraulic cylinder and the boom front side hydraulic cylinder, the boom is Main pressure oil is simultaneously sent to the bottom side oil chamber of the rear side hydraulic cylinder and the rod side oil chamber of the boom front side hydraulic cylinder. At the same time, the return oil from the rod side oil chamber of the boom rear side hydraulic cylinder and the bottom side oil chamber of the boom belly side hydraulic cylinder is returned to the other side circuit of the pressure oil supply / discharge circuit and the tank at the switching position of the directional control valve. It is returned to the oil tank through the communication oil passage. As a result, the boom back side hydraulic cylinder is extended and the boom ventral side hydraulic cylinder is contracted, so that the arm can be pivoted in one direction, for example, in the downward retracting direction without trouble. Next, by switching the direction switching valve to supply main pressure oil to the rod side oil chamber of the boom rear side hydraulic cylinder and the other side circuit leading to the bottom side oil chamber of the boom belly side hydraulic cylinder, the boom rear side Since the hydraulic cylinder is contracted and the boom ventilated hydraulic cylinder is expanded, the arm can be rotated in the other direction, for example, in the upward pushing direction without any trouble. As a result, it is possible to smoothly and strongly perform a rotating operation for adjusting the work position of a work tool or device such as a heavy crusher.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view of a hydraulic excavator 12 'that implements the hydraulic cylinder disposition method of the present invention. In the figure, 24 is a split type boom that is connected to the front part of the hydraulic excavator 12 'and can be split, 25 is a rear boom on the rear side of the boom 24, 26 is a front boom on the front side, and 27 is a tip part of the front boom 26. An arm connected to the arm 28, a crusher that is a working device attached to the tip of the arm 27, 29 a boom cylinder, 30 a boom back side arm cylinder as a boom back side hydraulic cylinder, and 31 a boom ventral side hydraulic cylinder. Boom ventral side arm cylinder, and 32 is a bucket cylinder.
FIG. 2 is a boom rear side arm cylinder 30 in FIG.
FIG. 3 is a main part circuit diagram showing an operation circuit of a boom ventral side arm cylinder 31. In the figure, 33 is a direction switching valve that controls switching between the boom rear-side arm cylinder 30 and the boom ventral-side arm cylinder 31, 34 is a main pump, and 35 is an oil tank. FIG. 3 is a side view of essential parts showing a state in which the crusher 28 shown in FIG. 1 is replaced with the backhoe bucket 36.

Next, a method of disposing the hydraulic cylinder of the present invention will be described with reference to FIGS. According to the present invention, of the split type boom 24 that is formed so as to be divided into the rear boom 25 and the front boom 26, the boom rear surface side arm cylinder 30 and the boom front surface side arm cylinder 31 are provided on the rear surface and the front surface of the front boom 26. Brackets 39 and 40 for connecting the base ends 37 and 38 (shown in FIG. 1) of the cylinder tubes are fixedly provided, and the rear side and the ventral side of the rear side of the arm 27 are provided with the both arm cylinders 3 respectively.
Brackets 43 and 44 for connecting the rod end portions 41 and 42 of Nos. 0 and 31 are fixed (fixed by welding in this embodiment), and the bracket 39 on the rear surface side of the front boom 26 and the arm 27 of the arm 27 are fixed. The boom rear-side arm cylinder 30 is provided between the rear-side bracket 43 and the front-boom-side bracket 40 of the front boom 26 and the front-side bracket 44 of the arm 27. The arm cylinder 31 is interposed. It is not always necessary to provide a single boom back side arm cylinder 30 and one boom back side arm cylinder 31 on the back side and the ventral side of the front boom 26, but a plurality of boom cylinders (not shown) are provided. It is also possible.

Further, according to the present invention, the pressure oil supply communicating with both arm cylinders 30 and 31 is controlled by the direction switching valve 33 (shown in FIG. 2) which controls the switching between the boom rear side arm cylinder 30 and the boom ventral side arm cylinder 31. A bottom side oil chamber 45 of the boom rear side arm cylinder 30 as an exhaust circuit,
The rod side oil chamber 46 of the boom abdominal surface side arm cylinder 31 is made to communicate with each other through the pipe lines 47 and 48 so that the one side circuit of the pressure oil supply / discharge circuit (which is a circuit in which the pipe lines 47, 48, 49 communicate with each other). Further, the rod-side oil chamber 50 of the boom rear-side arm cylinder 30 and the bottom-side oil chamber 51 of the boom abdominal-side arm cylinder 31 are connected to each other via pipe lines 52 and 53 so that the pressure oil supply / discharge circuit is formed. Circuit on the other side (pipe 5
2, 53, 54 are connected to each other).

Next, the operation of the hydraulic cylinder disposing method of the present invention will be described. In the present invention, since the boom back side arm cylinder 30 and the boom belly side arm cylinder 31 are arranged on the back side and the ventral side of the front boom 26, respectively, sufficient supporting force for holding the heavy crusher 28 is exhibited. be able to. Further, in the present invention, the boom back side arm cylinder 30 and the boom belly side arm cylinder 3 are provided.
When the directional control valve 33 for controlling the switching of No. 1 is switched from the neutral position to the C position, the main pressure oil from the main pump 34 flows through the pipe lines 55 and 56, the check valve 57, and the directional control valve 33.
Is supplied to the bottom side oil chamber 45 of the boom rear side arm cylinder 30 through the C position and the pipe lines 49 and 47, and a part of the main pressure oil is branched from the pipe line 49, and the boom is passed through the pipe line 48. The oil is supplied to the rod side oil chamber 46 of the abdominal surface side hydraulic cylinder 31. At the same time, the return oils from the rod-side oil chamber 50 of the boom rear-side arm cylinder 30 and the bottom-side oil chamber 51 of the boom abdominal-side arm cylinder 31 are returned to the pipe lines 52 and 53, the pipe line 54, and the direction switching valve 33, respectively. It is returned to the oil tank 35 through the position c. As a result, the boom back side hydraulic cylinder 30 is extended and the boom belly side hydraulic cylinder 31 is contracted, so that the arm 27 can be rotated without difficulty in the downward pulling direction. Next, when the direction switching valve 33 is switched to the two position, the main pressure oil from the main pump 34 is discharged from the conduit 5
5, 56, check valve 57, direction switching valve 33 two positions,
The oil is supplied to the rod-side oil chamber 50 of the boom rear-side arm cylinder 30 through the pipes 54 and 52, and a part of the main pressure oil is branched from the pipe 54, and the boom ventral side hydraulic cylinder is passed through the pipe 53. 31 is supplied to the bottom side oil chamber 51. At the same time, the boom rear arm cylinder 3
Return oil from the bottom side oil chamber 45 of 0 and the rod side oil chamber 46 of the boom abdominal surface side arm cylinder 31 passes through the two positions of the pipe lines 47 and 48, the pipe line 49, and the direction switching valve 33, and the oil tank. Returned to 35. As a result, the boom rear hydraulic cylinder 30 is contracted and the boom ventral hydraulic cylinder 31 is expanded, so that the arm 27 can be rotated in the upward pushing direction without any trouble. As a result, a rotating operation for adjusting the work position of the heavy crusher 28 can be smoothly and strongly performed.

When it is desired to perform excavation work with the hydraulic excavator 12 'having the hydraulic cylinder arrangement method according to the present invention, the crusher 28 shown in FIGS. 1 and 2 is removed and the bucket 36 shown in FIG. 3 is removed. Replace with. Boom rear side hydraulic cylinder 30 and boom ventral side arm cylinder 3
Since the hydraulic circuit for 1 does not change, the bucket 36 can be operated without any trouble and strongly. Even when a work tool / device other than the bucket 36 is attached, the same function as described above can be exerted.

[0013]

According to the present invention, since at least a single hydraulic cylinder is provided on each of the back side and the ventral side of the boom,
It is possible to exert sufficient supporting force for holding work tools and devices such as a heavy crusher. Further, according to the present invention, when the main pressure oil is supplied and circulated from the direction switching valve for controlling the switching between the boom rear side hydraulic cylinder and the boom front side hydraulic cylinder to the one side circuit of the pressure oil supply / discharge circuit leading to both the hydraulic cylinders, Since the rear side hydraulic cylinder extends and the boom front side hydraulic cylinder contracts, the arm can be rotated in one direction, for example, in the downward pulling direction without any trouble. Next, by switching the direction switching valve to supply main pressure oil to the rod side oil chamber of the boom rear side hydraulic cylinder and the other side circuit leading to the bottom side oil chamber of the boom belly side hydraulic cylinder, the boom rear side Since the hydraulic cylinder is contracted and the boom ventilated hydraulic cylinder is expanded, the arm can be rotated in the other direction, for example, in the upward pushing direction without any trouble. As a result, it is possible to smoothly and strongly perform a rotating operation for adjusting the work position of a work tool or device such as a heavy crusher.

[Brief description of drawings]

FIG. 1 is a side view of a hydraulic excavator that implements a method for disposing a hydraulic cylinder of the present invention.

FIG. 2 is a circuit diagram of essential parts showing an operation circuit of a boom rear-side arm cylinder and a boom ventral-side arm cylinder in FIG.

FIG. 3 is a side view of essential parts showing a state in which the crusher in FIG. 1 is replaced with a bucket for a backhoe.

FIG. 4 is a side view of a hydraulic excavator equipped with a front attachment according to an embodiment of the prior art.

FIG. 5 is a side view of a hydraulic excavator equipped with a work attachment according to an embodiment of the prior art.

[Explanation of symbols]

1 Front attachment 2,12,12 'Hydraulic excavator 4,14,26 Front boom 6,17,27 Arm 8,9,19,20,39,40,43,44 Bracket 10,21 Arm cylinder 11 Work attachment 16, 24 (split type) boom 18, 28 Crusher 25 Rear boom 30 Boom rear hydraulic cylinder 31 Boom ventral hydraulic cylinder 33 Direction switching valve 34 Main pump 45, 51 Bottom oil chamber 46, 50 Rod side oil chamber

Claims (3)

[Claims] 1. A construction machine, a work vehicle, etc., in which a boom, an arm, and a work tool are sequentially connected to a front portion of a vehicle body so as to be rotatable in the front-rear direction, and the arm is flexibly driven with respect to the boom. Brackets for fixing one end of the hydraulic cylinder to the back and the abdomen of the boom are fixed, and brackets for connecting various ends of the hydraulic cylinder to the back and the abdominal of the rear side of the arm. The boom rear side hydraulic cylinder is interposed between the boom rear side bracket and the arm rear side bracket, and the boom rear surface side bracket and the arm rear surface side bracket are mounted. A method for disposing a hydraulic cylinder, characterized in that a boom ventral side hydraulic cylinder is interposed between the hydraulic cylinder and the boom. 2. The rear side bracket and the abdominal surface side bracket for the boom are fixed to a front boom of a split type boom that is formed so as to be split into a rear boom and a front boom. How to arrange hydraulic cylinders. 3. A hydraulic cylinder arranging method according to claims 1 and 2, wherein a direction switching valve for controlling switching between the boom rear surface side hydraulic cylinder and the boom front surface side hydraulic cylinder is connected to the both hydraulic cylinders. As a pressure oil supply and discharge circuit that communicates with the bottom side oil chamber of the boom rear side hydraulic cylinder,
The one side circuit of the pressure oil supply / discharge circuit is formed by communicating with the rod side oil chamber of the boom belly side hydraulic cylinder, and the rod side oil chamber of the boom back side hydraulic cylinder and the bottom of the boom belly side hydraulic cylinder are connected. A method for arranging a hydraulic cylinder, characterized in that the other side circuit of the pressure oil supply / discharge circuit is formed by communicating with the side oil chamber.