JPH08100445A - Construction machine - Google Patents

Abstract

PURPOSE: To reduce the danger of an overturn by moving the position of the center of gravity of a counterweight to maintain balance. CONSTITUTION: A counterweight 14 is constituted of a counterweight box 15 fitted to an upper revolving superstructure 3 and consisting of an outer box 16 and an inner box 14, a heavy bob 19 movably stored in the inner box 17 of the counterweight box 15, and a heavy bob moving mechanism 20 moving the heavy bob 19 based on the detection signal from an inclination angle sensor detecting the inclination of the upper revolving superstructure 3. When the balance of the upper revolving superstructure 3 is easily collapsed during the excavating work on a slope, the position of the center of gravity of the counterweight 14 is automatically moved in response to the inclination of the upper revolving superstructure 3, and the balance of the upper revolving superstructure 3 is maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a hydraulic excavator,
The present invention relates to a construction machine having a counterweight on a vehicle body such as a hydraulic crane, a bulldozer, and a wheel loader.

[0002]

2. Description of the Related Art Generally, among construction machines such as hydraulic excavators and hydraulic cranes, for example, a hydraulic excavator is provided with an undercarriage and a rotatably mounted on the undercarriage, and a cab and a machine room are provided. An upper revolving structure, a work device that is provided on the front part of the upper revolving structure so as to be able to move upward and downward, and is provided at a rear part of the upper revolving structure and a work device including a boom, an arm, a bucket,
It is widely known that a counterweight that balances the upper swing body is used.

The hydraulic excavator thus constructed drives the hydraulic pump by the engine in the machine room,
The hydraulic fluid discharged from the hydraulic pump drives the undercarriage, the working device, and the like.

Further, during traveling and working, a counterweight balances the upper revolving structure to prevent a fall accident or the like.

[0005]

By the way, in the hydraulic excavator according to the above-mentioned prior art, a counterweight is provided at the rear of the upper swing body to balance the upper swing body when the working device is lowered and raised. Since the counterweight is formed by filling iron, concrete or the like in a box-shaped counterweight box, the center of gravity of the counterweight with respect to the upper swing body is always fixed.

As a result, for example, when excavation work is performed on a slope, the center of gravity of the upper swing body deviates in the inclination direction (lower side) in accordance with the swing motion of the upper swing body, so that when traveling on level ground. In comparison, there is a problem that the balance is poor and the risk of falling increases.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a construction machine capable of moving the center of gravity of the counterweight to maintain the balance and reduce the risk of falling. I am trying.

[0008]

In order to solve the above-mentioned problems, the construction machine according to the present invention has a construction in which a vehicle body, a working device movably provided in a front portion of the vehicle body, and a working device are provided. And a counterweight provided at the rear of the vehicle body to balance the vehicle body.

The construction of the construction machine according to the present invention is characterized in that the counterweight includes a counterweight box attached to the vehicle body, and a weight movably accommodated in the counterweight box. In order to move the position of the center of gravity of the weight according to the inclination of the vehicle body, the weight is moved in the counter weight box.

According to a second aspect of the present invention, the weight moving mechanism comprises a plurality of hydraulic cylinders provided between the counter weight box and the weight, and each hydraulic cylinder is compressed by a valve device. It may be configured to supply and drain oil.

[0011]

According to the structure of claim 1, when excavation work is performed on a slope, for example, when the vehicle body tilts in accordance with the turning motion of the vehicle body, the weight moving mechanism moves the weight to move the center of gravity of the counterweight. Adjusting the position keeps the car body balanced.

According to the second aspect of the present invention, the pressure oil is supplied to and discharged from each hydraulic cylinder from the valve device, for example, the inclination of the vehicle body is detected, and each hydraulic cylinder is controlled according to the inclination angle.

[0013]

1 to 6, a hydraulic excavator will be described as an example of a construction machine according to an embodiment of the present invention.

In the figure, 1 is a lower traveling body that is crawler-traveled by a traveling hydraulic motor (not shown), 2 is a turning device provided at the center of the upper portion of the lower traveling body 1, and 3 is a turning device 2. And an upper revolving structure 3 rotatably mounted on the lower traveling structure 1. The upper revolving structure 3 includes a revolving frame 4 having a frame structure, and the revolving frame 4 is provided on the revolving frame 4 and has an engine described later inside. 27, hydraulic pump 28
And the like, and a driver's cab 6 provided on the revolving frame 4 on the left side of the front of the machine room 5, and at the rear of the upper revolving structure 3 there is a counter described later. A weight 14 is provided.

Reference numeral 7 denotes a working device provided at the front part of the upper swing body 3, and the working device 7 is a boom 8 rotatably provided at the front part of the swing frame 4 and a tip end of the boom 8. Side rotatably provided on the side, and a backhoe type bucket 10 rotatably provided on the tip side of the arm 9.
The boom 8, the arm 9 and the bucket 10 are composed of two boom cylinders 11, two arm cylinders 12, 12, and a bucket cylinder 13 (only one boom cylinder 11 and one bucket cylinder 13 are shown). It is designed to be activated.

Reference numeral 14 denotes a counterweight located on the rear side of the machine room 5 and provided on the rear end side of the revolving frame 4.
As shown in FIGS. 2 and 3, the counterweight 14 is roughly composed of a counterweight box 15, a weight 19 and a weight moving mechanism 20 described later.

Reference numeral 15 denotes a counterweight box forming an outer shell of the counterweight 14, and the counterweight box 15 includes an outer box 16 and the outer box 16.
It is composed of an inner box 17 housed inside.

Here, the outer box 16 is attached to the rear end of the revolving frame 4, and the front and rear plates 16A,
16B, left and right plates 16C and 16D and upper and lower plates 16
The inner box 17 is formed from E and 16F into a box shape.
Is formed in a box shape smaller than the outer box 16 from the front and rear plates 17A and 17B, the left and right plates 17C and 17D, and the upper and lower plates 17E and 17F.

.. are located on the upper and lower ends of the outer box 16 and are arranged in a row in the left-right direction.
6A, a plurality of rollers rotatably mounted on the rear plate 16B, and each roller 18 supports the inner box 17 housed in the outer box 16 so as to be movable in the left-right direction.

Reference numeral 19 denotes a weight accommodated in the inner box 17, and the weight 19 is formed in a columnar shape extending in the left-right direction (width direction), and is filled with iron material or concrete. Further, the weight 19 includes cylinders 23 to
It is movably supported in the inner box 17 by 26.

Reference numeral 20 denotes a weight moving mechanism provided in the counter weight box 15 or the like for moving the position of the center of gravity of the counter weight 14, and the weight moving mechanism 20
Is roughly composed of left and right cylinders 21, 22, front and rear cylinders 23, 24, and upper and lower cylinders 25, 26 described later.

21 is left on the left plate 16C of the outer box 16,
A left cylinder 22 mounted so as to extend to the right
Indicates a right cylinder attached to the right plate 16D of the outer box 16 so as to face the left cylinder 21,
Rods 21A and 22A of the left and right cylinders 21 and 22
Are fixed to the left and right plates 17C and 17D of the inner box 17. The left and right cylinders 21 and 22 move the weight 19 together with the inner box 17 in the left and right directions.

Reference numeral 23 denotes a pair of front cylinders which are arranged in the inner box 17 so as to be spaced apart from each other in the left and right directions, and which are attached to the front plate 17A so as to extend in the front and rear directions, and 24 faces the front cylinder 23. A pair of rear cylinders (only one of which is shown in the figure) attached to the rear plate 17B are shown as follows.
At the tip of A, an arc-shaped support member 2 is formed along the outer shape of the weight 19.
3B and 24B are attached. The front and rear cylinders 23 and 24 move the weight 19 forward and backward while supporting the weight 19 from the front and rear.

Reference numerals 25, 25 are a pair of upper cylinders 26, 26 which are arranged in the inner box 17 so as to be spaced apart from each other in the left and right directions and which are attached to the upper plate 17E so as to extend upward and downward.
Indicates a pair of lower cylinders attached to the lower plate 17F so as to face the upper cylinders 25, respectively.
At the tips of the rods 25A, 26A of the lower cylinders 25, 26, arcuate support members 25B, 26B are formed along the outer shape of the weight 19.
Is installed. Then, each of the upper and lower cylinders 2
5, 26 support the weight 19 from above and below while supporting the weight 1
9 is moved up and down, and the cylinder 2
1 to 26 are composed of hydraulic cylinders.

Next, in FIG. 4, 27 is an engine provided in the machine room 5, 28 is a hydraulic pump driven by the engine 27, and 29 is a control valve connected to the hydraulic pump 28. The control valve 29 allows the pressure oil from the hydraulic pump 28 to flow into the cylinders 21 to 2
6 and other circuits (running hydraulic motor, turning hydraulic motor, etc.) are distributed and controlled.

Reference numeral 30 denotes a left and right electromagnetic throttle switching valve (only the left side is shown) as a valve device which is connected to the control valve 29 through a pipe 31 and supplies and discharges pressure oil to and from the cylinders 21, 23 to 26. The electromagnetic throttle switching valve 30 includes connection pipes 32A, 32B, 32C, 32D, 32E, 33A, 3
Cylinder 21, through 3B, 33C, 33D, 33E,
23 to 26 are connected. The electromagnetic throttle switching valve 30 supplies and discharges pressure oil (working oil) to and from the cylinders 21, 23 to 26 and the working oil tank 34.
The expansion and contraction control of 1, 23 to 26 is performed.

Reference numeral 35 is a relief valve connected in the middle of the pipe 31, and the relief valve 35 keeps the pressure in the pipe 31 constant.

Reference numeral 36 denotes a tilt angle sensor arranged in the cab 6 for detecting the tilt of the upper swing body 3, and 37 denotes a control signal to the electromagnetic type throttle switching valve 30 based on the detection signal of the tilt angle sensor 36. Controllers for outputting are shown respectively, and the electromagnetic throttle switching valve 30 is controlled by a control signal from the controller 37 to control the rods 21 of the cylinders 21, 23 to 26.
A and 23A to 26A are expanded and contracted.

Further, 38 is a supporting leg located inside the inner box 17 and attached to the center of the lower plate 17F. The supporting leg 38 supports the weight 19 when the counterweight 14 is assembled.

The hydraulic excavator according to this embodiment has the above-mentioned structure. Next, the movement of the center of gravity of the counterweight 14 will be described.

First, when operating a hydraulic excavator on uneven terrain, sloping ground, mud, etc., for example, when excavating work is performed while the upper revolving structure 3 is swiveling to the right while the entire hydraulic excavator is tilted to the right, The inclination state of the upper swing body 3 at this time is detected by the inclination angle sensor 36, and the controller 37 outputs a control signal to the electromagnetic throttle switching valve 30 based on the detection signal.

As a result, as shown in FIG. 5, the rod 22A of the right cylinder 22 extends to move the weight 19 together with the inner box 17 to the left side, and as shown in FIG. The rod 23A and the rod 26A of each lower cylinder 26 extend, and the weight 19 is moved backward and upward.

As a result, the center of gravity of the counterweight 14 moves rearward and upward from the position G to the position G'to move to the position G ', and the upper swing body 3 tends to be biased to the right in the working state described above. Is designed to balance the center of gravity of.

Thus, according to the present embodiment, even when the balance of the upper revolving structure 3 is likely to be lost, such as when excavating work on a slope, the counterweight 14 of the counterweight 14 is automatically adjusted according to the inclination of the upper revolving structure 3. By moving the position of the center of gravity, the balance of the upper swing body 3 can be maintained,
It is possible to reliably prevent the hydraulic excavator from falling over without lowering workability, and to greatly improve safety and reliability.

In the above embodiment, the electromagnetic throttle switching valve 30 is shown as a multiple valve, but instead of this, the cylinders 21 to 26 are individually provided with electromagnetic throttle switching valves. Good. Alternatively, a hydraulic throttle switching valve may be used as the valve device.

Further, in the above-mentioned embodiment, the tilt of the upper swing body 3 is detected by one tilt angle sensor 36, but the tilt may be detected by using two or more tilt angle sensors. Well, in this case, the detection accuracy can be improved.

Further, in the above embodiment, the outer box 16
A plurality of rollers 18, 18, ... Are used as means for supporting the inner box 17 so as to be movable in the left and right directions.
For example, a sliding plate or the like may be provided between the outer box 16 and the inner box 17 so that the inner box 17 slides in the left and right directions.

Further, in the above embodiment, the crawler type hydraulic excavator is exemplified as the construction machine, but the present invention is not limited to this, and for example, a wheel type hydraulic excavator or a hydraulic crane,
It can be widely applied to construction machines with other counter weights such as bulldozers and wheel loaders.

[0039]

As described above in detail, according to the invention of claim 1, the counterweight has a counterweight box attached to the vehicle body, and a weight movably accommodated in the counterweight box. In order to move the center of gravity of the weight according to the inclination of the vehicle body, the counterweight box is composed of a weight moving mechanism for moving the weight. Therefore, for example, when excavating work on a slope. However, when the vehicle body leans in accordance with the turning motion of the vehicle body, the weight moving mechanism moves the weight to adjust the position of the center of gravity of the counterweight, thereby maintaining the balance of the vehicle body and causing a fall accident. Can be prevented to improve safety and reliability.

According to a second aspect of the present invention, the weight moving mechanism is composed of a plurality of hydraulic cylinders provided between the counter weight box and the weight, and pressure oil is supplied to each of the hydraulic cylinders by a valve device. By supplying and discharging the pressure oil to and from each hydraulic cylinder from the valve device, for example, the inclination of the vehicle body can be detected, and each hydraulic cylinder can be controlled according to the inclination angle.

[Brief description of drawings]

FIG. 1 is an external view showing a hydraulic excavator according to an embodiment of the present invention.

FIG. 2 is a sectional view showing an internal structure of a counterweight in an enlarged manner as seen from the direction of arrows II-II in FIG.

FIG. 3 is a cross-sectional view showing an internal structure of a counterweight in an enlarged manner as seen from the direction of arrows III-III in FIG.

FIG. 4 is a hydraulic circuit diagram showing an overall configuration of a weight moving mechanism.

FIG. 5 is a cross-sectional view of the counter weight in a state where a weight or the like is moved, which is at the same position as in FIG.

FIG. 6 shows the counterweight with the weight moved.
It is sectional drawing of the position similar to FIG. 3 which shows from the arrow VI-VI direction in the inside.

[Explanation of symbols]

 3 Upper revolving structure (vehicle body) 7 Working device 14 Counter weight 15 Counter weight box 19 Weight 20 Weight moving mechanism 21 Left cylinder 22 Right cylinder 23 Front cylinder 24 Rear cylinder 25 Upper cylinder 26 Lower cylinder 30 Electromagnetic throttle switching valve ( Valve device) 36 Tilt angle sensor G, G'Center of gravity position

Claims (2)

[Claims] 1. A construction comprising a vehicle body, a working device movably provided at a front portion of the vehicle body, and a counterweight provided at a rear portion of the vehicle body to balance the vehicle body with respect to the working device. In the machine, the counterweight moves a counterweight box attached to the vehicle body, a weight movably accommodated in the counterweight box, and a center of gravity of the weight in accordance with the inclination of the vehicle body. Therefore, a construction machine comprising a weight moving mechanism for moving the weight in the counterweight box. 2. The weight moving mechanism comprises a plurality of hydraulic cylinders provided between the counterweight box and the weight, and a hydraulic fluid is supplied to and discharged from each hydraulic cylinder by a valve device. The construction machine according to claim 1, wherein: