JP2578500B2 - Power shovel - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power shovel, and more particularly, to a configuration of a front part of a power shovel and a driving mechanism thereof.

2. Description of the Related Art FIG. 6 shows the appearance of a conventional hydraulic power shovel. An upper revolving structure 2 is mounted on the lower traveling structure 1 so as to be freely rotatable, and a front portion 3 is attached to the upper revolving structure 2. The front part 3 is constituted by rotatably connecting a boom 4, an arm 5, and a bucket 6, and the operation of the front part 3 is all achieved by hydraulic cylinders 7, 8, and 9.

This hydraulic power shovel can perform five operations indicated by arrows. That is, the lower traveling body 1 moves forward and backward, the upper rotating body 2 turns right and left, and the boom hydraulic cylinder 7
Raising and lowering the boom 4 by using the hydraulic cylinder 8 for the arm
To lift and lower the arm 5 and discharge and scoop the bucket 6 by the bucket hydraulic cylinder 9. Reference numeral 10 denotes a rotation fulcrum for rotatably supporting the arm 5 on the boom 4. The lower traveling body 1 and the upper revolving body 2 are driven by a hydraulic motor (not shown).

Problems to be Solved by the Invention In the conventional hydraulic power shovel as shown in FIG. 6, the operating range of each joint driven by three hydraulic cylinders 7, 8, 9 is controlled to some extent by the stroke of the hydraulic cylinder and the joint mechanism. Because it is regulated, it is not possible to make full use of the arm length between each joint. Also, since the thrust direction of each cylinder and the thrust input point of each arm have a triangular function relationship,
There is a problem that the operating force is not always constant. Reference numeral 10 denotes a rotation fulcrum for rotatably supporting the arm 5 on the boom 4. That is, as shown in FIG. 7, the thrust of the cylinder is f (kgf), and the distance between the point of application of the cylinder and the fulcrum is r.
(M), assuming that the working angle between the thrust direction of the cylinder and the supporting arm is θ (degrees) and the working radius is 1 (m), the working force, ie, the moment m (kgf · m) is m = f · l = f · r.sin θ, and the effective operating force f changes according to the working angle θ. That is, there is a problem that the maximum thrust of the cylinder does not always work effectively. For the same reason, the tip of the bucket cannot always move at the same speed.

The present invention has been made in view of such a point,
The purpose is to keep the rotational force and rotational speed at each joint constant at all times, expand the working range of each joint mechanism, expand the working range, and enable work in narrow places. To provide a power shovel.

Means for Solving the Problems In order to achieve the above-mentioned object, according to the present invention, the driving of the front part is performed by a link motion constituted by an arm such as a boom, an arm, and a linear motion type cylinder, and each joint is driven. The coupling is a rotatable mechanism, and the boom, the arm, and the bucket are driven via a driving force transmitting means.

That is, the boom is formed in a gate-like shape, and is rotatably attached to the upper revolving structure. An arm is provided inside the boom so that one end of the boom rotates in the same direction as the arm. And a bucket is rotatably mounted on the other end of the arm such that the bucket rotates inside the boom in the same direction as the boom. Then, a first drive source for driving the boom is provided on the upper revolving unit, and second and third drive sources for driving the arm and the bucket are provided in the vicinity of the rotational connection between the boom and the upper revolving unit. Provided independently. Further, the driving force of the first driving source is transmitted to the boom by the first driving force transmitting means, the driving force of the second driving source is transmitted to the arm by the second driving force transmitting means, and the driving force of the third driving source is transmitted. The third driving force transmitting means is configured to transmit the driving force to the bucket.

Action The boom is driven by a first drive source provided on the upper
The arm is driven via the first driving force transmitting means, the arm is driven via the second driving force transmitting means by a second driving source provided in the vicinity of a rotational connection between the boom and the upper swing body, and the bucket is driven by the boom. And a third drive source provided in the vicinity of the rotation connection portion of the upper revolving unit through the third drive force transmitting means. Therefore, the rotational force at each joint is boom,
It is independent of the position of the arm and bucket, and the operating range of the front part is greatly expanded.

Also, since the boom has a gate-shaped shape, a combined body of an arm and a bucket is mounted inside the gate-shaped boom so that the arm and the bucket can rotate freely in the same direction as the rotation direction of the boom. Excavation work and earth removal work of the power shovel can be performed without turning the upper revolving structure, so that work efficiency can be improved and work in a narrow place can be performed.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an external front view of a power shovel according to an embodiment of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a partial sectional front view. First, referring to FIG. 1 and FIG.
An upper swing body 12 is mounted on the upper swing body 12 so as to be freely swingable, and a front portion 13 is attached to the upper swing body 12. The front part 13 includes a gate-shaped boom 14 having a first boom frame 15 and a second boom frame 16 connected at one end, and an arm 19 rotatably connected to the gate-shaped boom 14 by connecting parts 17 and 18. , And a bucket 20 rotatably connected to the arm 19.

As shown in FIG. 2, a first drive source 21 composed of, for example, a hydraulic motor is mounted on the upper revolving unit 12, and the first drive source 21 transmits a first tune (chain) 22 through a first tune (chain) 22. The gate-shaped boom 14 is rotated. As shown in FIG. 1, a second driving source 23 for driving an arm and a second driving source 23 for driving a bucket are provided in the vicinity of a rotary connection between the portal-shaped boom 14 and the upper revolving unit 12, for example. Three drive sources 24 are provided.

Next, the configuration of the front section 13 and its driving mechanism will be described in detail with reference to FIG. Bearing for upper revolving unit 12
A shaft 25 is rotatably supported by 30, and the boom 14 is fixed to the shaft 25 by keys 26 and 27. Also, axis 2
A sprocket (chain gear) 28 is fixed to 5 by a key 29, and the first chain 22 is wound around the sprocket 28. A sprocket 32 is fixed to an output shaft of the second drive source 23 for driving the arm by a spline 31.

The connecting portions 17, 18 between the portal-shaped boom 14 and the arm 19 are configured as follows. That is, the connecting portion 17 is provided with a shaft 34 rotatably via the bearing 36 on the first boom frame 15, and the arm 19 is attached to the shaft 34 by the key 35 so as to rotate integrally with the shaft 34. I have. In addition, axis 34
, A sprocket 40 is fixed by a spline 39. A second chain 33 is wound within the first boom frame 15 over the sprocket 32 and the sprocket 40 described above. On the other hand, a shaft 37 is connected to the connecting portion 18 via a bearing 38,
A sprocket 44 is fixed to one end of a shaft 37 by a spline 44, and a sprocket 47 is fixed to the other end by a spline 46.

A sprocket 42 is fixed to an output shaft of the third driving source 24 for driving the bucket by a spline 41, and the second boom frame extends over the sprocket 42 and the sprocket 45.
The third chain 43 is wound in the inside 16. Also arm
A shaft 51 is rotatably provided on the arm 19 via a bearing 52 at a connecting portion 50 between the bucket 19 and the bucket 20, and the bucket 20 is attached to the shaft 51 by a key 53 so that the bucket 20 is integrally rotated. ing. Further, a sprocket 55 is fixed to the center of the shaft 51 by a key 54, and a fourth chain 48 is wound in the arm 19 over the sprocket 47 and the sprocket 55. A plurality of claws 56 are provided at the tip of the bucket 20. 57 and 58 are hoses for supplying pressure oil to the second drive source 23 and the third drive source 24, respectively.

Next, the operation of the power shovel configured as described above will be described.

The operation of the lower traveling body 11 and the upper revolving superstructure 12 is the same as that of a conventional hydraulic excavator as shown in FIG. The rotation of the first drive source 21 is transmitted to the sprocket 28 via the first chain 22, and is transmitted by a key 29 to a shaft 25 rotatably supported on the upper traveling body 12 by a bearing 30.
This shaft 25 is connected to the first boom frame 15 via keys 26 and 27.
And the boss portion of the second boom frame 16, the gate-shaped boom 14 can be turned back and forth in the vehicle moving direction. The second drive source 23 is a spline
The sprocket 32 is rotated via the
, The shaft 34 is rotated by the spline 39, and this rotation is transmitted to the boss portion of the arm 19 by the key 35, thereby rotating the arm 19 back and forth.

Further, the rotation of the third drive source 24 is transmitted to the sprocket 42 by the spline 41, and the rotation of the sprocket 42 is transmitted to the sprocket 45 via the third chain 43.
The rotation of the sprocket 45 is transmitted to the fourth chain 48 via the spline 44, the shaft 37, the spline 46, and the sprocket 47, and the sprocket 55 is rotated by the chain 48. The rotation of the sprocket 55 is transmitted to the boss of the bucket 20 via the key 54, the shaft 51, and the key 53, and rotates the bucket 20.

FIG. 4 shows an example of the operation state of the above-described power shovel, in which excavation is performed in a state A on the left side of the figure, transportation is performed in a state B, and earth discharging is performed in a state C. 60 is a dump truck for loading earth and sand. As will be apparent from FIG. 4, it will be understood that the turning operation of the upper turning body which is required in the conventional power shovel shown in FIG. 6 is unnecessary.

FIG. 5 is an explanatory view showing the working range of the above-described embodiment. Since the lengths of the boom and the arm between the joints can be utilized 100%, the working range is larger than that of the conventional device shown in FIG. FIG.

In the above-described embodiment, an example is described in which a combination of a chain and a sprocket is adopted for the driving force transmission mechanism. However, the present invention is not limited to this, and a combination of a belt and a pulley, A combination of a belt and a sprocket, a combination of a wire and a drum, and the like can be adopted. Also, an example has been described in which a hydraulic motor is employed as the drive source, but an electric motor may be used instead of the hydraulic motor.

Effect of the Invention Since the present invention is configured as described in detail above, excavation work on the front side and earth removal or loading on a dump truck on the rear side can be performed without turning operation, so that work efficiency is improved. It is possible to work in a narrow place while improving. In addition, since the length of the arm between the joints is made 100%, the working range can be greatly expanded, and since the rotational force at each joint is always constant, the excavating force of the claw provided at the tip of the bucket and the fishing The force is constant in any posture.

In addition, since the drive source is provided near the rotary connection between the boom and the upper revolving unit, the weight at the front end can be reduced, power can be used effectively, and the front end can be made compact, so it can be used in narrow places. Work becomes possible.

[Brief description of the drawings]

1 is an external front view of a power shovel according to an embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is a partial cross-sectional front view of the power shovel according to the embodiment, and FIG. FIG. 5 is an explanatory view showing a series of operations of excavation, movement, and earth removal, FIG. 5 is an explanatory view showing an operation range of the power shovel of the present invention, FIG. 6 is a side view of a conventional typical hydraulic power shovel, FIG. FIG. 4 is an explanatory diagram showing a relationship between a thrust direction of a hydraulic cylinder and a thrust input point of each arm. 11 Lower traveling body, 12 Upper revolving superstructure, 13 Front part, 14 Gate-shaped boom, 15 First boom frame, 16 Second boom frame, 19 Arm, 20 … Bucket, 21… first drive source, 22… first chain, 23… second drive source, 24… third drive source, 33… second chain, 43… third chain, 48 ... The fourth chain.

Claims (2)

(57) [Claims] 1. A power shovel having a lower traveling structure, an upper revolving structure rotatably mounted on the lower traveling structure, and a front portion including a boom, an arm, and a bucket provided on the upper revolving structure. A boom is formed in a gate shape and is rotatably mounted on the upper revolving structure. One end of the arm is rotatably mounted on the tip of the boom so that the arm is positioned inside the boom having the gate shape. The other end of the arm is rotatably attached to a bucket, and a first drive source for driving the boom is provided on the revolving body, and the arm is provided near a rotational connection between the boom and the upper revolving body. And a second and a third driving source for driving the bucket and the bucket are independently provided, and a driving force of the first driving source is transmitted to the boom by a first driving force transmitting unit, and a driving of the second driving source is performed. Power A power transmission to the arm by a second driving force transmitting means, and transmitting the driving force of the third driving source to the bucket by a third driving force transmitting means. 2. The first, second and third drive transmission means are constituted by a combination of a chain and a sprocket, and the chain constituting the second drive force transmission means is accommodated in a frame on one side of the portal boom. 2. The power shovel according to claim 1, wherein one of the chains constituting the third driving force transmitting means is housed in a frame on the other side of the boom, and the other chain is housed in an arm.