WO2021235426A1

WO2021235426A1 - Work machine

Info

Publication number: WO2021235426A1
Application number: PCT/JP2021/018759
Authority: WO
Inventors: 大輔熊田
Original assignee: 日立建機株式会社
Priority date: 2020-05-21
Filing date: 2021-05-18
Publication date: 2021-11-25
Also published as: JP7287919B2; KR20220126296A; JP2021183767A; CN115135833A; EP4155464A1; US20230081760A1

Abstract

Provided is a work machine with which it is possible to turn an attachment while appropriately supporting a load acting on the attachment.　The work machine has: a hydraulic cylinder attached to the front surface of an arm, the hydraulic cylinder extending and contracting; a first link rod extended along the back surface of the arm; and a second link rod turnably supported on the side surface of the arm by a first pin that extends in the width direction of a front working machine, one end of the second link rod projecting toward the back-surface side of the arm and the other end projecting toward the front-surface side of the arm, one end of the first link rod being turnably connected to the attachment, the one end of the second link rod being turnably connected to the other end of the first link rod by a second pin that extends in the width direction of the front working machine, and the other end of the second link rod being turnably connected to the tip of a cylinder rod of the hydraulic cylinder by a third pin that extends in the width direction of the front working machine.

Description

Work machine

The present invention relates to a work machine equipped with a heavy attachment.

Conventionally, it is provided with a boom undulatingly supported by an upper swing body, an arm rotatably supported by the tip of the boom, and an attachment (for example, a bucket) rotatably supported by the tip of the arm. A hydraulic excavator is known (see, for example, Patent Document 1).

In the hydraulic excavator having the above configuration, the attachment generally operates in the direction of gravity when the hydraulic cylinder supported on the back surface of the arm extends, and operates in the direction opposite to the direction of gravity when the hydraulic cylinder contracts. be.

Japanese Unexamined Patent Publication No. 2020-26782

However, if the attachment that operates in the cloud is held by the hydraulic cylinder with the rod extended, a large load will be applied to the hydraulic cylinder. Further, such a problem becomes more remarkable as the weight of the attachment increases.

The present invention has been made in view of the above-mentioned actual conditions, and an object of the present invention is to provide a work machine capable of rotating an attachment while appropriately supporting a load acting on the attachment.

In order to achieve the above object, the present invention has a lower traveling body, an upper swinging body rotatably supported by the lower traveling body, a boom undulatingly supported by the upper swinging body, and a tip of the boom. A work machine including a rotatably supported arm and a front work machine having a rotatably supported attachment at the tip of the arm, wherein the arm is in the width direction of the front work machine. The front work has a pair of side surfaces facing each other and a ventral surface and a back surface each facing each other in a direction orthogonal to the width direction of the front working machine and each connected to the ends of the pair of side surfaces. The machine is attached to the ventral surface of the arm and expands and contracts by supplying and discharging hydraulic oil, and when the hydraulic cylinder expands, the attachment is dumped and the hydraulic cylinder contracts. It has a link mechanism for clouding the attachment, and the link mechanism has the arm by a first link rod extending along the back surface of the arm and a first pin extending in the width direction of the front work machine. It has a second link rod rotatably supported on the side surface of the arm, one end of which protrudes toward the back surface side of the arm, and the other end of which protrudes toward the ventral surface side of the arm, and one end of the first link rod. Is rotatably connected to the attachment, and one end of the second link rod is rotatably connected to the other end of the first link rod by a second pin extending in the width direction of the front working machine. The other end of the second link rod is rotatably connected to the tip of the cylinder rod of the hydraulic cylinder by a third pin extending in the width direction of the front working machine.

According to the present invention, the attachment can be rotated while appropriately supporting the load acting on the attachment. Issues, configurations and effects other than those described above will be clarified by the following description of the embodiments.

It is a side view of the work machine which concerns on this invention. It is a perspective view of an arm and a cutter. It is a figure which shows the posture of the cutter when the hydraulic cylinder is contracted. It is a figure which shows the posture of the cutter when the hydraulic cylinder is extended.

An embodiment of the work machine according to the present invention will be described with reference to the drawings. FIG. 1 is a side view of the work machine 1 according to the present invention. Unless otherwise specified, the front, back, left, and right in the present specification are based on the viewpoint of the operator who is on board and operates the work machine 1.

The work machine 1 includes a lower traveling body 2 and an upper turning body 3 supported by the lower traveling body 2. The lower traveling body 2 includes a pair of left and right crawlers 8. Then, when the rotation of the traveling motor (not shown) is transmitted and the pair of left and right crawlers 8 rotate, the work machine 1 travels. However, the lower traveling body 2 may be a wheeled type instead of the crawler 8.

The upper swivel body 3 is supported by the lower traveling body 2 so as to be swivelable. The upper swivel body 3 has a swivel frame 5 as a base, a cab (driver's seat) 7 arranged on the front left side of the swivel frame 5, and a front rotatably attached to the center of the front end of the swivel frame 5. It mainly includes a working machine 10 and a counter weight 6 arranged at the rear of the swivel frame 5 to balance the weight with the front working machine 10.

The cab 7 is formed with an internal space on which an operator who operates the work machine 1 is boarded. Inside the cab 7, a seat on which the operator is seated (not shown) and an operating device (steering, pedals, levers, switches, etc.) operated by the operator seated on the seat are arranged. Then, when the operator on the cab 7 operates the operating device, the lower traveling body 2 travels, the upper swivel body 3 turns, and the front working machine 10 operates.

The front working machine 10 includes a boom 11 rotatably supported by the upper swing body 3, an arm 12 rotatably supported by the tip of the boom 11, and a cutter rotatably supported by the tip of the arm 12. (Attachment) 13,

hydraulic cylinders

14, 15, 16 for driving a boom 11, an arm 12, and a cutter 13, a link mechanism 17, and a stopper 18 (see FIG. 2) are included.

The arm 12 has a ventral surface 12a, a back surface 12b, a left side surface (side surface) 12c, and a right side surface (not shown). The ventral surface 12a and the back surface 12b are surfaces facing each other in a direction orthogonal to the left-right direction (width direction of the front working machine 4). The left side surface 12c and the right side surface (a pair of side surfaces) are surfaces facing each other in the left-right direction. Then, the ventral surface 12a and the back surface 12b are connected to the ends of the left side surface 12c and the right side surface, respectively.

In particular, when the tip of the arm 12 is located in front of the tip of the boom 11 (when the hydraulic cylinder 15 is contracted to some extent), the ventral surface 12a faces downward and the back surface 12b faces upward. Then, the work machine 1 equipped with the cutter 13 performs the work in a state where the tip of the arm 12 is positioned in front of the tip of the boom 11 (that is, the ventral surface 12a faces downward and the back surface 12b faces upward). Is common.

The cutter 13 is an example of a dismantling attachment for gripping and dismantling an object (for example, a building). As will be described later, the cutter 13 has a large number of parts and is provided with a hydraulic actuator (swivel motor 13b,

hydraulic cylinder

13e, 13f), and therefore is heavier than an attachment such as a bucket. The cutter 13 mainly includes a mounting bracket 13a, a swivel motor 13b, a pair of

blades

13c and 13d, and a pair of

hydraulic cylinders

13e and 13f.

The mounting bracket 13a is rotatably supported by the tip of the arm 12 by a pin 13g extending in the left-right direction (width direction of the front working machine 10). Further, the mounting bracket 13a is rotatably connected to one end of a link rod 17a, which will be described later, by a pin 13h extending in the left-right direction. The pin 13h is arranged on the back surface 12b side of the arm 12 with respect to the pin 13g. In other words, in the working posture of the front working machine 10, the pin 13h is arranged above the pin 13g.

The swivel motor 13b rotates the component parts 13c to 13f with respect to the mounting bracket 13a by supplying and discharging the hydraulic oil. The swivel motor 13b rotates the components 13c to 13f around a rotation axis extending in a direction orthogonal to the

pins

13g and 13h. The hydraulic oil is supplied to the swivel motor 13b from a hydraulic pump (not shown) mounted on the upper swivel body 3, and returns from the swivel motor 13b to the hydraulic oil tank (not shown) mounted on the upper swivel body 3.

The pair of

blades

13c and 13d are opened and closed by supplying and discharging hydraulic oil to the pair of

hydraulic cylinders

13e and 13f. More specifically, the hydraulic oil is supplied to the bottom chambers of the

hydraulic cylinders

13e and 13f, and the hydraulic oil is discharged from the rod chamber, so that the pair of

blades

13c and 13d are closed. On the other hand, the hydraulic oil is supplied to the rod chambers of the

hydraulic cylinders

13e and 13f, and the hydraulic oil is discharged from the bottom chamber, so that the pair of

blades

13c and 13d are opened.

The hydraulic cylinder 16 expands and contracts when hydraulic oil is supplied and discharged. The hydraulic cylinder 16 has a cylinder tube 16a, a piston (not shown), a cylinder rod 16b, and a cap 16c. The hydraulic cylinder 16 extends in the longitudinal direction of the arm 12 along the back surface of the arm 12. Further, in the hydraulic cylinder 16, the base end of the cylinder tube 16a is rotatably supported on the base end side of the arm 12, and the tip of the cylinder rod 16b is rotatably connected to a link rod 17b described later.

The cylinder tube 16a is a cylindrical member capable of supplying and discharging hydraulic oil. The base end side of the cylinder tube 16a is closed and the tip end side is open. The piston reciprocates in the cylinder tube 16a. Further, the piston divides the internal space of the cylinder tube 16a into a bottom chamber on the proximal end side and a rod chamber on the cap 16c side.

One end of the cylinder rod 16b is connected to the piston, and the other end protrudes to the outside of the cylinder tube 16a through the cap 16c. The cap 16c is attached to the tip of the cylinder tube 16a by a bolt (not shown) or the like. The cap 16c is formed with a through hole that allows the cylinder rod 16b to protrude and prevents the piston from protruding.

When the hydraulic oil is supplied from the hydraulic pump to the bottom chamber and the hydraulic oil returns from the rod chamber to the hydraulic oil tank, the piston moves in the direction of projecting the cylinder rod 16b from the cylinder tube 16a (hereinafter, this operation is referred to as "hydraulic cylinder". It is expressed as "extension of 16"). On the other hand, when the hydraulic oil is supplied from the hydraulic pump to the rod chamber and the hydraulic oil returns from the bottom chamber to the hydraulic oil tank, the piston moves in the direction of immersing the cylinder rod 16b in the cylinder tube 16a (hereinafter, this operation is referred to as "this operation". It is described as "reduction of the hydraulic cylinder 16").

FIG. 2 is a perspective view of the arm 12 and the cutter 13. The link mechanism 17 is connected to the cutter 13 and the hydraulic cylinder 16. The link mechanism 17 rotates the cutter 13 with respect to the arm 12 by expanding and contracting the hydraulic cylinder 16. As shown in FIGS. 1 and 2, the link mechanism 17 includes a long rod-shaped link rod 17a (first link rod) and a pair of long rod-shaped link rods 17b (second link rod) in the left-right direction. It has extending

pins

17c, 17d, 17e (first pin, second pin, third pin).

The link rod 17a is arranged on the back surface 12b side of the arm 12. The link rod 17a extends along the back surface 12b of the arm 12. However, the link rod 17a does not have to be parallel to the back surface 12b. One end of the link rod 17a is rotatably connected to the mounting bracket 13a by the pin 13h. Further, the other end of the link rod 17a is rotatably connected to one end of the pair of link rods 17b by a pin 17d.

The pair of link rods 17b are rotatably supported by pins 17c on the left side surface 12c and the right side surface of the arm 12. One end of the pair of link rods 17b protrudes toward the back surface 12b of the arm 12, and the other end protrudes toward the ventral surface 12a of the arm 12. One end of the pair of link rods 17b (the end on the back surface 12b side) is rotatably connected to the other end of the link rod 17a by a pin 17d. Further, the other end of the pair of link rods 17b (the end on the ventral surface 12a side) is rotatably connected to the tip of the cylinder rod 16b by a pin 17e. Further, as shown in FIG. 3, the distance A between the

pins

17c and 17e is set to be equal to or greater than the distance B between the

pins

17c and 17d (A ≧ B).

Further, as shown in FIG. 2, the stopper 18 is fixed to the back surface 12b of the arm 12. The stopper 18 is fixed to the back surface 12b at a position where the other end of the link rod 17a abuts when the hydraulic cylinder 16 is extended. Further, the upper surface of the stopper 18 has a concave shape along the other end of the link rod 17a.

FIG. 3 is a diagram showing the posture of the cutter 13 when the hydraulic cylinder 16 is reduced. When the hydraulic cylinder 16 is reduced, the link rod 17b rotates counterclockwise in FIG. 3 around the pin 17c. In other words, the link rod 17b is rotated around the pin 17c so that the end portion on the back surface 12b side moves to the tip end side of the arm 12 and the end portion on the ventral surface 12a side moves to the base end side of the arm 12. Move.

As a result, the link rod 17a moves in the direction of pushing the cutter 13 at the position of the pin 13h (that is, above the pin 13g). As a result, the cutter 13 rotates (that is, cloud operation) in the direction indicated by the arrow in FIG. The "cloud operation" is an operation of rotating the cutter 13 toward the ventral surface 12a of the arm 12. Then, when the tip of the arm 12 is located in front of the tip of the boom 11, the cloud operation rotates the cutter 13 in the direction of gravity.

FIG. 4 is a diagram showing the posture of the cutter 13 when the hydraulic cylinder 16 is extended. When the hydraulic cylinder 16 is extended, the link rod 17b rotates clockwise around the pin 17c in FIG. In other words, the link rod 17b is rotated around the pin 17c so that the end portion on the back surface 12b side moves to the base end side of the arm 12 and the end portion on the ventral surface 12a side moves to the tip end side of the arm 12. Move.

As a result, the link rod 17a moves in the direction of pulling the cutter 13 at the position of the pin 13h (that is, above the pin 13g). As a result, the cutter 13 rotates (that is, dumps) in the direction indicated by the arrow in FIG. The "dump operation" is an operation of rotating the cutter 13 toward the ventral surface 12a of the arm 12. Then, when the tip of the arm 12 is located in front of the tip of the boom 11, the dump operation rotates the cutter 13 in a direction opposite to the direction of gravity (hereinafter, referred to as "anti-gravity direction").

Further, the other end of the link rod 17a comes into contact with the stopper 18 at the timing when the hydraulic cylinder 16 is extended to the maximum or immediately before this (that is, the timing before the hydraulic cylinder 16 is extended to the maximum). The timing at which the hydraulic cylinder 16 is extended to the maximum is, for example, the timing at which the piston comes into contact with the inner surface of the cap 16c. This prevents the cutter 13 from further rotating in the antigravity direction. As a result, the force in the direction of further extending the hydraulic cylinder 16 is blocked from being transmitted from the cutter 13 to the hydraulic cylinder 16 through the link mechanism 17.

According to the above embodiment, for example, the following effects are exhibited.

In the hydraulic cylinder 16 according to the above embodiment, the pressure receiving area on the bottom side of the piston is larger than the pressure receiving area on the rod side to which the cylinder rod 16b is connected. Further, the hydraulic cylinder 16 when the protrusion amount of the cylinder rod 16b is small can stably hold the load as compared with the case where the protrusion amount of the cylinder rod 16b is large.

Therefore, according to the above embodiment, since the hydraulic cylinder 16 causes the cutter 13 to operate in the cloud by contracting, the cutter 13 is held with a larger force than when the cutter 13 is held in the extended state of the hydraulic cylinder 16. be able to. Therefore, when working with the tip of the arm 12 protruding forward from the tip of the boom 11, even if an unexpected load is applied to the cutter 13 and the cutter 13 tries to further rotate toward the ventral surface 12a of the arm 12, the hydraulic pressure is increased. The cylinder 16 can stably support the cutter 13 with a sufficiently large force.

Further, the

link rods

17a and 17b are elastically deformed by being loaded with a load. Therefore, the link mechanism 17 also functions as a cushioning material that absorbs the load applied to the cutter 13 and prevents propagation to the hydraulic cylinder 16. That is, according to the above embodiment, the load applied from the cutter 13 to the hydraulic cylinder 16 can be reduced.

Further, according to the above embodiment, by setting the distance A between the

pins

17c and 17e to be equal to or larger than the distance B between the

pins

17c and 17d, the force generated by the hydraulic cylinder 16 is amplified and the cutter 13 is used. Can be communicated. As a result, the load acting on the cutter 13 can be supported more appropriately.

Further, according to the above embodiment, the link rod 17a comes into contact with the stopper 18 at the timing before the hydraulic cylinder 16 extends to the maximum. As a result, it is possible to prevent the force in the direction of further extending the hydraulic cylinder 16 from being transmitted from the cutter 13 to the hydraulic cylinder 16 through the link mechanism 17. As a result, it is possible to prevent the cylinder rod 16b from being pulled out more than necessary and the cap 16c from coming off.

Although the cutter 13 has been described as an example of the attachment in the above embodiment, the specific example of the attachment is not limited to this. As another example, the attachment may be a hanging attachment with hooks for suspending the suspended load. It should be noted that the present invention exerts a particularly advantageous effect by applying it to the work machine 1 provided with a heavy attachment.

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 Work machine 2 Lower running body 3 Upper swivel body 5 Swing frame 6 Counterweight 7 Cab 8 Crawler 10 Front work machine 11 Boom 12 Arm 12a Abdominal surface 12b Back surface 12c Left side (side surface)
13 Cutter (attachment)

13a Mounting bracket

13b Swing motor

13c,

13d Blade

13g,

13h Pin

13e, 13f, 14, 15, 16 Hydraulic cylinder 16 Hydraulic cylinder

16a Cylinder tube

16b Cylinder rod 16c Cap 17 Link mechanism 17a Link rod (1st link rod)
17b link rod (second link rod)
17c pin (1st pin)
17d pin (2nd pin)
17e pin (3rd pin)
18 Stopper

Claims

With the lower running body,
An upper swivel body supported so as to be swivelable to the lower traveling body,
Work provided with a boom undulatingly supported by the upper swing body, an arm rotatably supported at the tip of the boom, and a front working machine having an attachment rotatably supported at the tip of the arm. It ’s a machine,
The arm
A pair of side surfaces facing each other in the width direction of the front working machine,
It has a ventral surface and a back surface that face each other in a direction orthogonal to the width direction of the front working machine and each of which is connected to the ends of the pair of side surfaces.
The front working machine is
A hydraulic cylinder that is attached to the ventral surface of the arm and expands and contracts when hydraulic oil is supplied and discharged.
It has a link mechanism for dumping the attachment when the hydraulic cylinder is extended and clouding the attachment when the hydraulic cylinder is contracted.
The link mechanism is
A first link rod extending along the back surface of the arm,
A first pin extending in the width direction of the front working machine is rotatably supported on the side surface of the arm, one end of which protrudes toward the back surface of the arm, and the other end of which protrudes toward the ventral surface of the arm. Has 2 link rods
One end of the first link rod is rotatably connected to the attachment.
One end of the second link rod is rotatably connected to the other end of the first link rod by a second pin extending in the width direction of the front working machine.
A work machine characterized in that the other end of the second link rod is rotatably connected to the tip of the cylinder rod of the hydraulic cylinder by a third pin extending in the width direction of the front work machine.
In the work machine according to claim 1,
A work machine characterized in that the distance between the first pin and the third pin is equal to or greater than the distance between the first pin and the second pin.
In the work machine according to claim 1,
A work machine that is fixed to the back surface of the arm and has a stopper that prevents the attachment from further dumping by abutting the first link rod before the hydraulic cylinder extends to the maximum.