JP6971212B2 - 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 low-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. When dismantling a structure having a large ground height, such as a high-rise building, the excavator 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, the front device has an articulated structure having three links (multi-boom and middle arm and arm), so that it is a low-rise structure. Even in the dismantling of, the working radius becomes large and a wide range can be dismantled efficiently.

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, since it is difficult to grasp the floor or the like spreading horizontally from above, it is possible to grasp the floor or the like from the horizontal direction (horizontal direction) to improve the work efficiency. However, in the conventional hydraulic excavator disclosed in Patent Document 1 and the like, when working in a range close to the driver's seat of the vehicle body, it is difficult to position the work tool such as the crusher attached to the tip end side of the arm in a horizontal position. There is a problem that the work efficiency at the time of dismantling the low-rise structure is poor because the work of grasping the floor and pillars of the low-rise structure from the side and crushing the structure cannot be performed.

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 low-layer 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 end side of the boom. Work that is rotatably connected to the tip side of the middle arm via the first support shaft, and rotatably attached to the tip 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 has two linear extending portions that are continuous at an blunt angle through a bend portion, and the work tool cylinder is larger than the bend portion. It is arranged along the linear extending portion located on the tip side, the boom operates so as to be lowered, the tip side of the middle arm rotates in a direction approaching the vehicle body, and the arm moves toward the first body. When both the linear extending portion located on the rear end side of the bent portion and the working tool are grounded on the ground in a state of being rotated in a direction approaching the vehicle body via a support shaft. The bent portion is characterized in that it is located above the straight line connecting the first support shaft and the second support shaft.

According to the work machine of the present invention, the work tool such as a crusher can be placed in a horizontal posture even at a low work height, so that the work efficiency at the time of low-layer 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 type 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. It is preferably used.

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 in front 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 low-rise structure, the work tool 14 such as a crusher or a breaker is selectively attached to the tip side of the arm 13. Be done.

In such a multi-boom type 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 bending angle θ of the distal end side linear portion 13b by the bent portion 13c, that is, the bending angle θ of the distal end side linear portion 13b that bends downward with respect to the virtual line along the axial direction of the proximal end side linear portion 13a is about. It is set to (25 ± 5) degrees. The work tool cylinder 20 is arranged along the longitudinal direction of 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, both the base end side linear portion 13a of the arm 13 and the work tool 14 are grounded to the ground E. When made to do so, the arm 13 is held in a chevron shape in which the bent portion 13c is located on the upper 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 entire arm 13 can be placed on the ground E in a stable posture for work. Damage to the tool 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 the low-rise structure is dismantled by using the hydraulic excavator 1 according to the present embodiment, when the work tool 14 is used to work in a range close to the driver's seat (cab 6) of the vehicle body, the arm 13 The tip side linear portion 13b is bent forward by a predetermined bending angle θ (25 ± 5 degrees) with respect to the axial direction of the tip side linear portion 13b. As a result, the range in which the work tool 14 such as the crusher attached to the linear portion 13b on the tip side can be kept in a horizontal posture becomes wide, so that the floor or pillar of the low-rise structure is grasped from the side by the work tool 14 and crushed. It is possible to significantly improve the work efficiency at the time of low-layer dismantling.

Further, in the hydraulic excavator 1 according to the present embodiment, even when the middle arm 12 is rotated to dismantle the middle layer portion, the work tool 14 can be in a horizontal posture, and the floor or pillar of the middle layer structure can be set. Work such as grasping from the side and crushing can be easily performed. Further, when the front device 4 is folded and stored in the minimum posture, both the base end side linear portion 13a of the arm 13 and the work tool 14 can be installed on the ground E to maintain the horizontal posture. The maintainability of 4 can be improved.

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 work tool 103 attached to the tip end side of the arm 102 is used. When dismantling a low-rise structure using the work tool 103, the work tool 103 can be kept in a horizontal posture if it is far from the driver's seat of the car body, but the work tool 103 is kept in a horizontal posture in a range close to the driver's seat of the car body. Will be difficult. As a result, when the area is close to the driver's seat of the vehicle body, the floor or pillar of the low-rise structure cannot be grasped from the side by the work tool 14 and crushed, resulting in poor work efficiency at the time of dismantling the low-rise structure.

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 an obtuse-angled continuous proximal end side linear portion 13a and a distal end side linear shape via the bent portion 13c. Since the work tool cylinder 20 is arranged along the longitudinal direction of the linear portion 13b on the tip side and is formed in a dogleg shape as a whole while having the portion 13b, the driver's seat of the vehicle body ( When dismantling a low-rise structure in a range close to the cab 6), the tip side linear portion 13b of the arm 13 has a predetermined bending angle θ (25 ± 5 degrees) with respect to the axial direction of the tip side linear portion 13b. Only the posture is bent forward. As a result, the range in which the work tool 14 such as the crusher attached to the linear portion 13b on the tip side can be kept in a horizontal posture becomes wide, so that the floor or pillar of the low-rise structure is grasped from the side by the work tool 14 and crushed. It is possible to significantly improve the work efficiency at the time of low-layer dismantling.

Further, in the hydraulic excavator 1 according to the present embodiment, when both the base end side linear portion 13a and the work tool 14 are grounded to the ground E, the first support shaft 17 closer to the middle arm 12 and the work tool 14 are closer to each other. The bent portion 13c is held in a chevron shape located above the straight line L connecting the second support shaft 18, and the work tool cylinder 20 is formed between the ground E and the tip side linear portion 13b. Since it is arranged inside, 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 bending angle θ of the linear portion 13b on the tip side by the bending portion 13c of the arm 13 is too small, it becomes difficult to put the work tool 103 in a horizontal posture within a range close to the driver's seat of the vehicle body, and conversely, the above angle θ is set. If it is too large, it will be difficult to put the work tool 14 in a vertical posture when disassembling the middle layer portion, so that it will not be possible to hold the wall of the middle layer structure or the like from above with the work tool 14 in the vertical posture. For this reason, in the hydraulic excavator 1 according to the present embodiment, the bending angle θ of the linear portion 13b on the tip side by the bending portion 13c is set in the range of about (25 ± 5) degrees, so that from the middle layer portion. It is possible to improve work efficiency in a wide range over a low-rise area.

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.

In the arm 13 according to the modified example configured in this way, the shape ratio of the proximal end side linear portion 13a and the distal end side linear portion 13b is different, the bending angle θ of the bending portion 13c is different, and the like. By preparing several types of upper arms having different types, 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.
The arm has two linear extending portions that are obtusely continuous through the bending portion, and the work tool cylinder is located on the tip side of the bending portion at the linear extending portion. Arranged along and
The bent portion is in a state where the boom operates so as to be lowered, the tip end side of the middle arm is rotated in a direction approaching the vehicle body, and the arm is rotated in a direction approaching the vehicle body via the first support shaft. When both the linear extending portion and the working tool located on the rear end side are grounded on the ground, the bent portion is relative to the straight line connecting the first support shaft and the second support shaft. A work machine characterized by being located on the upper side. 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 two linear extending portions and the bending portion. In the work machine according to claim 1,
A work machine characterized in that the bending angle of the bent portion is set in the range of 25 ± 5 degrees.

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