JPH0514254U - Arm type work vehicle - Google Patents

Abstract

(57) [Summary] [Purpose] Even when the arm stretches greatly in the front-rear direction of the vehicle body, it is possible to reliably counteract the load acting on the work body and prevent the vehicle body from leaning or falling. [Arrangement] An arm 4 for performing joint movement is provided on the front side of the vehicle body 1, a work body 5 such as a bucket is supported at the tip of this arm 4, and a counterweight 8 is moved forward and backward in the vehicle body 1 on the rear side of the vehicle body 1. The hydraulic cylinder 10 is supported as much as possible, and the hydraulic cylinder 10 is driven by the drive unit 11 to move the counterweight 8 forward and backward corresponding to the expansion and contraction of the arm. Even if the acting moment becomes large, the counterweight 8 advances to increase the opposite moment, and
Against the load acting on.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an arm type work vehicle such as a power shovel and a backhoe, and more particularly to an arm type work vehicle including an arm that performs relative movement and a counterweight.

[0002]

[Prior Art]

 Conventionally, for example, an arm type work vehicle is described with a power shovel. A vehicle body is rotatably provided on a traveling portion having a caterpillar, an arm for articulating is provided on the front side of the vehicle body, and a bucket is provided at the tip of the arm. In addition to supporting the work body such as, the counter weight is fixed to the rear side of the vehicle body, and the arm is extended and contracted so that the work body can perform excavation and transfer of earth and sand.

[0003]

[Problems to be solved by the device]

 By the way, in this conventional arm type work vehicle, although the counterweight is used for balancing, the resistance received from the ground and the like increases with the extension of this arm increasing in the longitudinal direction of the vehicle body. When the work such as a bucket is excessively loaded due to an increase in the amount of earth and sand to be transferred, the tilt of the vehicle body may become large, or the vehicle body may fall down in some cases.

The present invention has been made in view of the above problems, and an object thereof is to reliably counteract a load acting on a work body even when the extension of the arm increases in the vehicle front-rear direction. The point is to prevent the body from tilting or falling.

[0005]

[Means for Solving the Problems]

 The means of the present invention for solving such a problem is to provide an arm for articulating on the front side of the vehicle body, support the work body at the tip of this arm, and equip the counterweight on the rear side of the vehicle body. An arm type work vehicle is provided with a support portion for supporting the counterweight so as to be able to advance and retreat in the front-back direction of the vehicle body, and a drive portion for moving the counterweight forward and backward.

[0006]

[Action]

 According to the arm type work vehicle having the above-described configuration, when the arm that performs articulation greatly extends to the front of the vehicle body, if the counterweight is advanced to the rear of the vehicle body by the drive unit, the load on the work body becomes excessive in this state. Even if the moment acting on the vehicle body is increased due to the counterweight, the counterweight advances and the momentum in the opposite direction also increases, so the load acting on the work body can be reliably counteracted, and the leaning or tilting of the vehicle body is prevented. To be prevented. On the other hand, when the arm that performs joint movement contracts, the counterweight is retracted by the drive unit to achieve the balance.

[0007]

【Example】

 Hereinafter, an arm type work vehicle according to an embodiment of the present invention will be described with reference to the accompanying drawings. As shown in FIGS. 1 to 3, an arm type work vehicle according to an embodiment is a power shovel, a traveling unit 2 provided with a caterpillar 3 is rotatably provided with a vehicle body 1, and a joint is provided on the front side of the vehicle body 1. A moving arm 4 is provided, and a work body 5 such as a bucket is supported at the tip of the arm 4. The tip node 6 of the arm 4 supporting the work body 5 can be rotated about the longitudinal direction of the tip node 6 by the rotation mechanism 7 so that the degree of freedom for changing the direction of the work body 5 is increased. ..

Further, as shown in FIG. 2, a counterweight 8 is provided on the rear side of the vehicle body 1. The counterweight 8 is supported by a pair of hydraulic cylinders 10 as supporting portions so as to be able to move forward and backward in the vehicle body 1. The hydraulic cylinder 10 is driven by the drive unit 11.

The drive unit 11 controls the hydraulic oil of the hydraulic cylinder 10 so as to move the counterweight 8 forward and backward in response to the expansion and contraction of the arm 4 in the vehicle front-rear direction. That is, as shown in FIG. 3, the counterweight 8 has its forward / backward movement position half radius r determined in proportion to the ground direction radius R of the arm 4, and is proportional to the extension when the arm 4 extends in front of the vehicle body 1. It is positioned at the rear position of the vehicle body.

Reference numeral 12 denotes a pair of guides provided between the hydraulic cylinders 10, which guides a slider 13 extending from the counterweight 8 slidably by a guide member 14, and firmly supports the counterweight 8. I have to.

Therefore, according to the power shovel according to the present embodiment, the arm 4 is expanded and contracted by the joint movement, and the tip node 6 of the arm 4 is rotated at a proper time so that the work body 5 excavates and transfers earth and sand. To do. In this case, as shown in FIG. 3, when the arm 4 greatly extends to the front of the vehicle body 1, the drive unit 11 causes the counterweight 8 to advance to the rear of the vehicle body 1 via the hydraulic cylinder 10. At this time, if a large resistance is applied to the work body 5 from the ground or an excessive load is applied to the work body 5 due to an increase in the amount of earth and sand loaded on the work body 5, the moment acting on the vehicle body 1 However, since the counterweight 8 is advanced, the moment in the opposite direction is also increased accordingly. Therefore, the counterweight 8 can reliably oppose the load acting on the work body 5, and the vehicle body 1 Tilt and fall are prevented.

[0012] Particularly, in this power shovel, since the tip node 6 of the arm 4 supporting the work body 5 is rotatable, the weight of the arm 4 is increased due to the presence of the rotation mechanism 7, and the moment around the vehicle body is increased. However, this can be dealt with by the advancement of the counterweight 8 described above. Further, as shown in FIG. 3, when the work body 5 is turned outward and the earth and sand are loaded, the moment acting on the vehicle body 1 becomes particularly large, which can also be dealt with by the advance of the counterweight 8 described above. Is.

Further, as shown in FIG. 1, when the arm 4 is contracted, the counterweight 8 is retracted by the driving unit 11, so that balance is achieved and the vehicle body 1 is rotated by the contracted amount. It prevents other collisions such as driving.

In the above embodiment, the drive unit 11 drives the hydraulic cylinder 10 so as to move the counterweight 8 forward and backward in proportion to expansion and contraction of the arm 4 in the front-rear direction of the vehicle body 1. However, this is not always the case. The present invention is not limited to this, and the arm 4 may be advanced when it extends beyond the predetermined length in front of the vehicle body 1, or may be operated in a timely manner by a switch operation. Further, the supporting portion is not limited to the hydraulic cylinder 10 and may be appropriately changed by using a gear mechanism such as a rack and a pinion.

Further, although the above-described embodiment applies the present invention to a power shovel, the present invention is not necessarily limited to this, and may be applied to other arm type work vehicles such as a backhoe. Of course. Further, the working unit is not limited to the above-mentioned bucket, and may have any form such as a dipper, a crushing hand, and a magnet.

[0016]

[Effect of the device]

 As described above, according to the arm type work vehicle of the present invention, the counterweight can be moved back and forth in the front-rear direction of the vehicle body, so that the load acts on the work body excessively and the moment applied to the vehicle body increases. However, by adjusting the advance position of the counterweight, the moment in the opposite direction can be increased and the load acting on the work can be reliably counteracted. Therefore, it is possible to prevent the vehicle body from tilting or collapsing, and improve performance and safety. Further, since it is possible to withstand the load of the arm itself, it is possible to cope with a heavy arm having a rotation mechanism and the like, which has the effect of increasing the degree of freedom in manufacturing.

[Brief description of drawings]

FIG. 1 is a view showing an arm type work vehicle according to an embodiment of the present invention.

FIG. 2 is a plan view showing a main part of an arm type work vehicle according to an embodiment of the present invention.

FIG. 3 is a view showing the operation of the arm type work vehicle according to the embodiment of the present invention.

[Explanation of symbols]

 1 vehicle body 4 arm 5 working body 8 counterweight 10 hydraulic cylinder 11 drive unit

Claims (1)

[Scope of utility model registration request] 1. An arm type working vehicle in which an arm for articulating is provided on a front side of a vehicle body, a work body is supported on a tip end of the arm, and a counterweight is provided on a rear side of the vehicle body. An arm type work vehicle comprising: a support portion that supports the front and rear directions of the counter weight so as to be movable back and forth; and a drive portion that moves the counterweight forward and backward.