JP6983741B2 - Work machine - Google Patents

Description

The present invention relates to a work machine such as a hydraulic excavator, and particularly relates to a work machine suitable for dismantling a high-rise structure.

A hydraulic excavator as a typical example of a work machine has a vehicle body composed of a self-propelled lower traveling body and an upper rotating body mounted on the upper part of the lower traveling body so as to be able to turn. A front device is provided on the front side so as to be rotatable in the vertical direction. Then, when dismantling a structure having a large ground height such as a high-rise building, it is used as a hydraulic excavator in which a front device for dismantling work is attached to the front side of the upper swivel body.

Normally, the front device for dismantling work has a plurality of booms called a multi-boom, and the multi-boom has a lower boom rotatably attached to the front part of the upper swing body and a tip of the lower boom. It is composed of a joint boom attached to the side and an upper boom attached to the tip end side of the joint boom (see, for example, Patent Document 1). Then, the middle arm is rotatably connected to the tip side of the upper boom, the arm is rotatably connected to the tip side of the middle arm, and a work tool such as a crusher is attached to the tip side of the arm. ing. Further, a boom cylinder is attached between the lower boom and the upper swing body, and the front device is moved up and down by the expansion and contraction of the boom cylinder.

When dismantling a structure or the like with a hydraulic excavator equipped with a front device having such a configuration, if a joint boom is connected between the lower boom and the upper boom to lengthen the total length of the multi-boom, it can be attached to the tip side of the arm. Since the work height of the crusher and the like is increased, the dismantling work of the high-rise structure can be easily performed.

Japanese Unexamined Patent Publication No. 2011-256626

By the way, the work tool such as a crusher attached to the tip end side of the arm has a limitation in the opening width and a limitation in the thickness of the wall that can be grasped. Therefore, it is difficult to grasp the wall spreading in the front from the front, and if the wall can be grasped from above, the work efficiency is improved. However, in the conventional hydraulic excavator disclosed in Patent Document 1 and the like, when the front device is lifted to the maximum height in order to crush the wall of a high-rise structure or the like, even if the work tool is to be rotated downward, the work tool may be rotated downward. Since the stroke of the cylinder that rotates the work tool is limited, it is difficult to hold the wall of the high-rise structure from above with the work tool in a vertical position, and there is a problem that the work efficiency at the time of dismantling the high-rise structure is poor. ..

The present invention has been made from the actual situation of such a prior art, and an object of the present invention is to provide a work machine capable of improving work efficiency at the time of high-rise dismantling.

In order to achieve the above object, the work machine of the present invention is rotatably connected to a self-propelled vehicle body, a boom attached to the vehicle body so as to be able to move up and down, and the tip side of the boom. Work that is rotatably connected to the tip end side of the middle arm via the first support shaft, and rotatably attached to the tip end side of the arm via the second support shaft. A tool, a middle arm cylinder mounted between the boom and the middle arm, an arm cylinder mounted between the middle arm and the arm, and mounted between the arm and the work tool. In a work machine provided with a work tool cylinder, the arm supports the first support shaft, and has a base end side linear portion in which one end of the arm cylinder is connected to a ventral surface, and the second support. While supporting the shaft, the tip side linear portion in which the work tool cylinder is arranged along the back surface and the ventral surfaces and back surfaces of the proximal end side linear portion and the tip end side linear portion are connected at an blunt angle. When the middle arm and the arm attached to the work machine via the boom have a bent portion and the back surface of the linear portion on the base end side is brought into contact with the ground, the bent portion is formed. The portion is located below the straight line connecting the first support shaft and the second support shaft, and the bent portion is arranged at a position closer to the second support shaft than the first support shaft. It is characterized by.

According to the work machine of the present invention, since the work tool such as a crusher can be maintained in a vertical posture at a high work height, the work efficiency at the time of high-rise dismantling can be improved. Issues, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

It is a side view which shows the hydraulic excavator which concerns on embodiment of this invention. It is a side view of the arm provided in the hydraulic excavator of FIG. It is explanatory drawing which shows the working posture of the front device provided in the hydraulic excavator of FIG. It is explanatory drawing which shows the working posture of the front device provided in the hydraulic excavator which concerns on a comparative example. It is a side view of the arm which concerns on a modification.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 is a side view showing a multi-boom hydraulic excavator 1 which is an example of a work machine according to an embodiment of the present invention. As shown in FIG. 1, the hydraulic excavator 1 includes a self-propelled lower traveling body 2 and an upper rotating body 3 that is mounted on the lower traveling body 2 so as to be able to turn and constitutes a vehicle body together with the lower traveling body 2. , It is roughly configured by the front device 4 described later, which is provided on the front side of the upper swing body 3 so as to be able to move up and down, and is suitably used for dismantling a structure having a large ground height such as a high-rise building. It is a thing.

The upper swivel body 3 includes a swivel frame 5 as a base, a cab 6 arranged on the left side of the front portion of the swivel frame 5 to define a driver's cab, and a counterweight arranged on the rear end side of the swivel frame 5. 7 and a building cover 8 arranged on the front side of the counterweight 7 and accommodating on-board equipment such as an engine and a hydraulic pump (not shown) are roughly configured.

The front device 4 includes a multi-boom consisting of a lower boom 9, a plurality of joint booms 10, and an upper boom 11, a middle arm 12 rotatably connected to the tip side of the upper boom 11, and a tip side of the middle arm 12. It is roughly composed of an arm 13 rotatably connected and a working tool 14 rotatably connected to the tip end side of the arm 13.

The base end side of the lower boom 9 is rotatably connected to the swivel frame 5 on the front right side of the upper swivel body 3, and a plurality of joint booms 10 are pin-coupled to the tip end side of the lower boom 9. .. The upper boom 11 is pin-coupled to the tip end side of the joint boom 10, and the base end side of the middle arm 12 is rotatably connected to the tip end side of the upper boom 11 via a support shaft 15. A boom cylinder (not shown) is attached between the lower boom 9 and the upper swing body 3, and the expansion and contraction of the boom cylinder causes the multi-boom (lower boom 9, joint boom 10, upper boom 11) to move in the vertical direction. Rotates (up and down).

A middle arm cylinder 16 is attached between the base end side of the middle arm 12 and the upper boom 11, and the middle arm 12 rotates about a support shaft 15 due to expansion and contraction of the middle arm cylinder 16.

The base end side of the arm 13 is rotatably connected to the tip end side of the middle arm 12 via the first support shaft 17, and the work tool 14 is connected to the tip end side of the arm 13 via the second support shaft 18. It is rotatably attached. An arm cylinder 19 is attached between the middle arm 12 and the base end side of the arm 13, and the arm 13 rotates about the first support shaft 17 due to expansion and contraction of the arm cylinder 19.

A work tool cylinder 20 is attached between the tip end side of the arm 13 and the work tool 14, and the work tool 14 rotates about the second support shaft 18 due to expansion and contraction of the work tool cylinder 20. The work tool 14 is an attachment having a function suitable for the work content of the hydraulic excavator 1, and in the case of dismantling work of a high-rise structure, the work tool 14 such as a crusher or a breaker is attached to the tip end side of the arm 13.

In such a multi-boom hydraulic excavator 1, the characteristic configuration of the present invention is that the shape of the arm 13 is devised. Hereinafter, the specific configuration and action / effect of the arm 13 will be described in detail.

FIG. 2 is a side view of the arm 13, in which the arm 13 includes a base end side linear portion 13a on which the first support shaft 17 is provided, a tip end side linear portion 13b on which the second support shaft 18 is provided, and these. It has a base end side linear portion 13a and a bent portion 13c connecting the tip end side linear portion 13b at an obtuse angle, and is formed in a dogleg shape as a whole. The angle θ1 formed by the proximal end side linear portion 13a and the distal end side linear portion 13b is set to about 155 degrees (± 5 degrees), in other words, the distal end side linear portion 13b is the proximal end side linear portion 13a. It bends upward with an angle θ2 of about 25 degrees (± 5 degrees) with respect to the virtual line along the axial direction of. The work tool cylinder 20 is arranged along the tip side linear portion 13b, and the rod side of the work tool cylinder 20 is supported by the work tool 14. Further, the bottom side of the work tool cylinder 20 is supported by a cylinder bracket 21 provided at a connection point between the bent portion 13c and the tip side linear portion 13b.

As shown in FIG. 2, assuming that the virtual line connecting the first support shaft 17 and the second support shaft 18 is a straight line L, when the base end side linear portion 13a of the arm 13 is grounded to the ground E, the arm 13 , The bent portion 13c is held in a valley shape located on the lower side of the straight line L. As a result, the work tool cylinder 20 is arranged in the space formed between the ground E and the linear portion 13b on the tip side, so that the arm 13 can be placed on the ground E in a stable posture, and the work tool can be placed on the ground E. Damage to the cylinder 20 is also prevented.

FIG. 3 is an explanatory view showing the working posture of the front device 4 provided with the arm 13 having such a shape. As shown in FIG. 3, when dismantling a high-rise structure using the hydraulic excavator 1 according to the present embodiment, the multi-boom and the middle arm 12 are lifted to the maximum height so that the work tool 14 faces directly downward. When the arm 13 is lifted (with the work tool 14 fully rolled up), the tip side linear portion 13b bends downward by a predetermined angle θ2 (25 ± 5 degrees) with respect to the base end side linear portion 13a of the arm 13. It will be in the state of. As a result, even if the work tool 14 attached to the linear portion 13b on the tip side is in a vertical posture, there is a margin in the extension side stroke of the work tool cylinder 20, so that the range in which the work tool 14 can be kept in the vertical posture is widened. be able to. Therefore, for example, when a crusher is used as a work tool 14 to crush a wall or a chimney of a high-rise structure, the wall or the chimney of the high-rise structure is grasped from above while keeping the crusher (work tool 14) in a vertical position. The height that can be achieved becomes higher, and the work efficiency at the time of dismantling a high-rise building can be significantly improved.

Further, in the hydraulic excavator 1 according to the present embodiment, even when the middle arm 12 is rotated to work on the middle layer portion, the work tool 14 can be in a horizontal posture, and the floor, pillars, etc. of the middle layer structure can be placed. Work such as crushing by grasping from the side with a crusher can be easily performed. Further, when the front device 4 is folded and stored in the minimum posture, the linear portion 13a on the base end side of the arm 13 can be installed on the ground E to maintain the horizontal posture, so that the maintainability of the front device 4 is improved. Can be done.

FIG. 4 is an explanatory diagram showing a working posture of a front device provided with a conventional linear arm as a comparative example of the hydraulic excavator 1 according to the present embodiment.

As shown in FIG. 4, in the case of the hydraulic excavator 100 according to the comparative example, since the arm 102 of the front device 101 has a straight shape having no bent portion, the multi-boom 103 and the middle arm 104 are lifted to the maximum height. When the arm 102 is lifted so that the work tool 105 faces directly downward (with the work tool 105 rolled up to the maximum), there is no margin in the extension side stroke of the work tool cylinder 106 attached to the tip end side of the arm 102, so that the work is performed. The tool 105 cannot be placed in a vertical position. Therefore, even if the multi-boom 103 and the middle arm 104 are lifted to the maximum height in an attempt to crush the wall of the high-rise structure, the work tool 105 is held in a vertical position at a high position and the wall of the high-rise structure is grasped from above. It becomes difficult and the work efficiency at the time of dismantling the high-rise building becomes poor.

As described above, in the hydraulic excavator 1 according to the present embodiment, the arm 13 which is a constituent member of the front device 4 has a linear portion 13a on the base end side and a linear linear portion on the tip end side which are continuous at an blunt angle via the bent portion 13c. Since the work tool cylinder 20 is arranged along the linear portion 13b on the tip side and is formed in a dogleg shape as a whole while having the portion 13b, the multi-boom and the middle arm 12 have a maximum height. When the high-rise structure is dismantled by lifting it up, the range in which the work tool 14 attached to the linear portion 13b on the tip side can be kept in a vertical posture can be widened. Therefore, when a work tool 14 such as a crusher is used to crush a wall or the like of a high-rise structure, the wall or the like of the high-rise structure can be grasped from above while keeping the work tool 14 in a vertical posture. , Work efficiency at the time of high-rise dismantling can be remarkably improved.

Further, in the hydraulic excavator 1 according to the present embodiment, when the base end side linear portion 13a of the arm 13 is grounded to the ground E, the first support shaft 17 closer to the middle arm 12 and the second support closer to the work tool 14 Since the bent portion 13c is located below the straight line L connecting the shafts 18 and the work tool cylinder 20 is arranged in the space formed between the ground E and the linear portion 13b on the tip side, the front device 4 The arm 13 can be grounded in a horizontal position when the front device 4 is in the retracted position, and the maintainability of the front device 4 can be improved.

If the angle θ1 formed by the base end side linear portion 13a and the tip end side linear portion 13b of the arm 13 is too small, it becomes difficult to widen the range in which the work tool 14 can be kept in the vertical posture when disassembling the high-rise portion. On the contrary, if the angle θ1 is too large, it becomes difficult to put the work tool 14 in a horizontal posture when disassembling the middle layer portion. For this reason, in the hydraulic excavator 1 according to the present embodiment, the angle θ1 formed by the linear portion 13a on the proximal end side and the linear portion 13b on the distal end side is set to about 155 degrees (± 5 degrees). It is possible to improve work efficiency in a wide range from the high-rise part to the middle-rise part.

FIG. 5 is a side view showing a modified example of the arm 13. As shown in FIG. 5A, the arm 13 according to the modified example includes a lower arm 13d rotatably connected to the middle arm 12 via a first support shaft 17 and a base end side linear portion 13a. It is composed of an upper arm having a linear portion 13b on the distal end side and a bent portion 13c, and these lower arms 13d and the upper arm are connected via a detachable pin 22. Then, as shown in FIG. 5B, the arm 13 can be divided into a lower arm 13d and an upper arm by removing the detachable pin 22.

The arm 13 according to the modified example configured in this way has a different shape in advance, such as different dimensional ratios of the base end side linear portion 13a and the tip end side linear portion 13b, and different bending angles of the bent portion 13c. By preparing several different types of upper arms, it is possible to connect the optimum upper arm according to the height of the dismantled structure, the work content, and the like to the lower arm 13d to form the arm 13.

It should be noted that the above-described embodiments are examples for the purpose of explaining the present invention, and the scope of the present invention is not limited to those embodiments. Those skilled in the art can practice the invention in various other embodiments without departing from the gist of the invention.

1 Hydraulic excavator 2 Lower traveling body 3 Upper swivel body 4 Front device 9 Lower boom 10 Joint boom 11 Upper boom 12 Middle arm 13 Arm 13a Base end side linear part (straight extension part)
13b Tip side straight part (straight extension part)
13c Bent part 13d Lower arm 14 Work tool 15 Support shaft 16 Middle arm cylinder 17 1st support shaft 18 2nd support shaft 19 Arm cylinder 20 Work tool cylinder 21 Cylinder bracket L Straight line E Ground

Claims (4)

A self-propelled vehicle body, a boom attached to the vehicle body so that it can move up and down, a middle arm rotatably connected to the tip side of the boom, and a first support shaft on the tip side of the middle arm. An arm rotatably connected via a working tool, a work tool rotatably attached to the tip end side of the arm via a second support shaft, and a boom and a middle arm. In a work machine including a middle arm cylinder, an arm cylinder attached between the middle arm and the arm, and a work tool cylinder attached between the arm and the work tool.
Said arm,
A linear portion on the base end side in which one end of the arm cylinder is connected to the ventral surface while supporting the first support shaft.
A linear portion on the tip side in which the work tool cylinder is arranged along the back surface while supporting the second support shaft, and
It has a bent portion that connects the ventral surfaces and the back surfaces of the proximal end-side linear portion and the distal end-side linear portion at an obtuse angle.
When the middle arm attached to the work machine via the boom and the arm are bent and the back surface of the linear portion on the base end side is brought into contact with the ground, the bent portion becomes the first support shaft. It is located on the lower side of the straight line connecting the second support axis and
A work machine characterized in that the bent portion is arranged at a position closer to the second support shaft than the first support shaft. In the work machine according to claim 1,
A work machine characterized in that a cylinder bracket that supports one end of the work tool cylinder is provided close to the bent portion. In the work machine according to claim 1,
The arm is divided into a lower arm rotatably connected to the middle arm via the first support shaft and an upper arm connected to the lower arm via a detachable pin. A work machine characterized in that the upper arm is provided with the base end side linear portion, the tip end side linear portion, and the bent portion. In the work machine according to claim 1,
When the middle arm attached to the work machine via the boom and the back surface of the base end side linear portion are brought into contact with the ground in a bent state, the back surface of the tip end side linear portion and the back surface of the linear portion. A work machine characterized in that the crossing angle with the ground is set in the range of 25 ± 5 degrees.

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