JP7141986B2 - working machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a working machine equipped with an articulated working device including a boom and an arm, and more particularly to a working machine in which a boom cylinder and an arm cylinder are arranged below the boom.

2. Description of the Related Art A work machine configured by attaching an attachment having a gripping mechanism such as a grapple to a hydraulic excavator is sometimes used for cargo handling work such as loading of objects onto a truck (see Patent Document 1, etc.).

JP 2012-127051 A

Hydraulic excavators used for excavation work generally have an arm cylinder installed on the upper surface (back side surface) of the boom, and are configured such that when the arm cylinder is extended, the working device performs an arm cloud operation. This is to make the cylinder extension motion with high output correspond to the arm crowding motion which is frequently used during excavation. However, in a working machine that requires force to lift an object gripped by the attachment, that is, to dump the arm, it is desirable to associate the cylinder extension motion with the arm dump motion. For that purpose, it is necessary to install a bracket (hereinafter referred to as an arm bracket) that connects the base of the arm cylinder to the lower surface (ventral surface) of the boom.

As for the boom cylinder, since the boom raising operation requires more force than the boom lowering operation, it is usually configured so that the boom is raised when extended. The tip of the boom cylinder is often connected to the side of the boom, but for work machines that frequently take a position in which the boom is lifted and an object is lifted, the bracket that connects the tip of the boom cylinder (hereinafter referred to as the boom bracket) is attached to the boom. A configuration that sits on the underside of the unit may be desirable. This is to prevent the foot pins that support the boom from coming too close to the boom cylinder when the boom is erected.

An object of the present invention is to ensure a wide range of motion of the arm with respect to the stroke of the arm cylinder and to improve the support strength of both cylinders in a configuration in which the arm cylinder and the boom cylinder are arranged on the underside of the boom. To provide a working machine capable of

In order to achieve the above object, the present invention includes a working machine main body and a working device attached to the working machine main body, wherein the working device includes a boom rotatably connected to the working machine main body; The boom cylinder comprises an arm rotatably connected to a boom, an attachment attached to the arm, two boom cylinders for driving the boom, and an arm cylinder for driving the arm. and in a working machine in which the arm cylinder is arranged below the boom, a first pin that supports a tip end of the boom cylinder, a second pin that supports a base end of the arm cylinder, and the first pin. a boss, left and right boom brackets provided on the lower surface of the boom to support the boss, and left and right arm brackets provided on the lower surface of the boom to support the second pin, the left and right boom brackets comprising: The left and right arm brackets are interposed between, and the boom bracket and the arm bracket are partially overlapped when viewed from the left and right ,
An end portion of the arm bracket on the boom tip side protrudes from the boom bracket toward the boom tip side, and the second pin is supported by the protruding portion, and the base of the arm cylinder is provided between the left and right arm brackets. The left and right arm brackets and the base ends of the arm cylinders are connected to each other by the second pin, and the boss penetrates the left and right boom brackets and the left and right arm brackets to extend through the bosses. and the first pin is passed through the two boom cylinders and the boss .

According to the present invention, in the configuration in which the arm cylinder and the boom cylinder are arranged on the lower side of the boom, it is possible to ensure a wide range of motion of the arm with respect to the stroke of the arm cylinder, and to improve the support strength of both cylinders.

1 is a side view showing the overall configuration of a working machine according to one embodiment of the present invention; FIG. 2 is a side view of a working device (front working device) provided in the working machine shown in FIG. 1; FIG. 2 is an enlarged side view showing a boom bracket that supports the tip of a boom cylinder and an arm bracket that supports the base end of an arm cylinder and the surrounding structure provided in the working machine shown in FIG. 1; FIG. 2 is an enlarged bottom view showing a boom bracket supporting a tip end of a boom cylinder and an arm bracket supporting a base end of an arm cylinder provided in the working machine shown in FIG. 1 and the surrounding structure thereof; FIG. 4 is a side view of the boom bracket and arm bracket shown in FIG. 3; A bottom view of the boom bracket and arm bracket shown in FIG. Cross-sectional view taken along line VII-VII in Fig. 5 Cross-sectional view taken along line VIII-VIII in FIG.

Embodiments of the present invention will be described below with reference to the drawings.

－Working machine－
FIG. 1 is a side view of a working machine according to one embodiment of the present invention, and FIG. 2 is a side view of a working device (front working machine) provided in the working machine shown in FIG. In FIG. 2, facilities other than the working device mounted on the revolving frame (described later) (such as an operator's cab) and a cylinder cover (described later) are omitted from the illustration. Hereinafter, the front of the revolving body 12 is defined as the direction in which the operator sitting in the driver's seat faces (the direction in FIG. 1). The working machine shown in FIG. 1 uses a hydraulic excavator as a base machine, and includes a working machine main body 10 and a working device 20 attached to the working machine main body 10 . The working machine body 10 includes a traveling body 11 and a revolving body 12 .

The traveling body 11 constitutes the base structure of the working machine, and is a crawler-type traveling body having left and right crawler belts 13 . The left and right crawler belts 13 are driven by left and right traveling drive devices 14, respectively. The traveling drive device 14 consists of a hydraulic motor and a speed reducer. The revolving body 12 is provided on the running body 11 via a revolving wheel 15. By driving the revolving wheel 15 with a revolving motor (not shown), the revolving body 12 rotates relative to the running body 11 about a vertically extending axis. swirl. The swing motor is a hydraulic motor, but in addition to using an electric motor, there are cases where both a hydraulic motor and an electric motor are used. In the present embodiment, the working machine including the traveling body 11 as the base structure is exemplified, but in harbors and the like, there are working machines that use a post fixed to the ground as the base structure. There are also working machines that use a wheel-type traveling body as a base structure. The present invention can also be applied to such work machines.

The revolving body 12 includes a revolving frame 16, an operator's cab 17, a machine room 18, a counterweight 19, and the like. The revolving frame 16 is a base frame of the revolving body 12 and supports each device mounted on the revolving body 12 . The driver's cab 17 is located on one side (the left side in this example) in the left-right direction of the front portion of the revolving frame 16 . A driver's seat (not shown) in which an operator sits, an operation device operated by the operator, and the like are arranged in the operator's cab 17 . The machine room 18 is arranged behind the operator's cab 17 in the revolving frame 16 . Although not shown in particular, the machine room 18 houses a prime mover, which is an engine (internal combustion engine), a hydraulic pump driven by the prime mover, a control valve for controlling the hydraulic oil that drives the hydraulic actuator, heat exchangers, and the like. It is An electric motor may be used as the prime mover. Tanks and the like are arranged on the opposite side of the operator's cab 17 across the work device 20 in the front portion of the revolving frame 16 . Tanks include fuel tanks, hydraulic oil tanks, and the like. The counterweight 19 is a weight that balances the working device 20 and is supported at the rear end of the revolving frame 16 .

- working equipment -
The working device 20 is an articulated working machine, and includes a working arm 21 and an attachment 22 . The working arm 21 includes a boom 23 , an arm 24 , a boom cylinder 25 , an arm cylinder 26 and an attachment cylinder 27 . In this embodiment, the boom cylinder 25, the arm cylinder 26, and the attachment cylinder 27 are all arranged below the working device 20 (for example, below the boom 23 and the arm 24 extending forward). The boom cylinder 25, arm cylinder 26 and attachment cylinder 27 are all hydraulic cylinders. Two boom cylinders 25 are arranged side by side, and only one arm cylinder 26 and one attachment cylinder 27 are provided.

The boom 23 is connected to the front portion of the base frame (revolving frame 16) of the revolving body 12 via a foot pin P1 extending laterally so as to be vertically rotatable. The lower surface of the boom 23 of the present embodiment (the ventral surface that faces downward when extended forward) is configured as a flat surface that is not curved or bent. The arm 24 is rotatably connected to the tip of the boom 23 via a pin P2 extending laterally.

The boom cylinder 25 is connected at its base end to the work machine body 10 (the revolving frame 16 of the revolving body 12) via a laterally extending pin P11, and is attached to the bottom surface of the boom 23 via a laterally extending pin P12. The ends are connected to each other. The arm cylinder 26 has a base end connected to the bottom surface of the boom 23 via a laterally extending pin P13, and a distal end connected to the bottom surface of the arm 24 via a laterally extending pin P14. In the present embodiment, when a long object W such as a piece of wood (FIG. 1) is gripped by the attachment 22, the arm cylinder 26 arranged below the boom 23 and the long object W do not interfere with each other. A cylinder cover C surrounds the cylinder 26 . The attachment cylinder 27 has a base end connected to the lower surface of the arm 24 via a laterally extending pin P15, and a distal end connected to a base end of the link 28 via a laterally extending pin P16. The intermediate portion of the link 28 is connected to the distal end of the arm 24 via a pin P3 extending laterally.

The attachment 22, which is a grapple in this example, includes a gripping mechanism and a pivoting mechanism for pivoting the gripping mechanism, and is suspended from the tip of a link 28 via a pin P17. FIG. 1 illustrates a state in which a long object W is gripped and lifted by the attachment 22 . It should be noted that other work tools such as a bucket can be used as the attachment 22, and the grapple can be removed together with the link 28 and replaced with another work tool.

In addition, as described above, the boom cylinder 25 , the arm cylinder 26 and the attachment cylinder 27 are arranged below the working device 20 . Therefore, all of these cylinders drive the driven members (the boom 23, the arm 24 and the attachment 22) in the direction to lift the attachment 22 by extension operation. In other words, each cylinder is configured to exert a stronger driving force in the work of lifting an object gripped by the grapple.

-bracket-
FIG. 3 is an enlarged side view showing a boom bracket that supports the tip of the boom cylinder, an arm bracket that supports the base end of the arm cylinder, and the surrounding structure, and FIG. 4 is a bottom view thereof. 5 is a side view of the boom bracket and arm bracket shown in FIG. 3, FIG. 6 is a bottom view thereof, FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 5, and FIG. It is an arrow directional cross-sectional view along line VIII. As shown in these figures, the work machine includes a pair of left and right boom brackets 31, a pair of left and right arm brackets 32, bosses 33 and reinforcing plates 34. As shown in FIG.

The boom bracket 31 is a member that supports the boss 33, and is provided at the left and right edges of the lower surface 23a of the boom 23 in the middle portion of the boom 23 in the longitudinal direction. The left and right boom brackets 31 protrude downward (ventral side) from the bottom surface 23a of the boom 23 and are fixed to the bottom surface 23a of the boom 23 by welding, for example. These left and right boom brackets 31 are steel plates formed in a mountain shape that is convex downward when viewed from the left and right direction. vertical plane extending back and forth).

The arm bracket 32 is a pair of left and right steel plates that support a pin P13 that supports the base end (tube side end) of the arm cylinder 26 . The left and right arm brackets 32 protrude downward (ventral side) from the lower surface 23a of the boom 23 and are fixed to the lower surface 23a of the boom 23 by welding, for example. These left and right arm brackets 32 have the same position, shape and size in the longitudinal direction of the boom 23, and are interposed between the left and right boom brackets 31 so as to partially overlap the boom bracket 31 when viewed from the left and right. are arranged parallel to the The base end of the arm cylinder 26 is inserted between the left and right arm brackets 32, and the pin P13 is passed through the left and right arm brackets 32 and the arm cylinder 26 to prevent the base end of the arm cylinder 26 from being removed from the boom 23. They are rotatably connected.

The boom base end side end of the arm bracket 32 is aligned with the boom base end side end of the boom bracket 31 in the boom longitudinal direction. The arm bracket 32 is longer than the boom bracket 31 , and the end of the arm bracket 32 on the boom tip side protrudes from the boom bracket 31 toward the boom tip side. The pin P13 is supported by a portion that protrudes further toward the tip of the boom than the boom bracket 31. The pin P13 is configured so as not to overlap the boom bracket 31 when viewed from the left and right while being supported by the arm bracket 32. (Fig. 3). As a result, the pin P13 can be pulled out and inserted to the left and right without interfering with the boom bracket 31. As shown in FIG.

The boss 33 is a member that supports the first pin P12 that supports the tip (rod-side end) of the boom cylinder 25. It is fixed to bracket 31 and arm bracket 32 . The length of the boss 33 is longer than the width of the boom 23 , and the left and right ends protrude from the boom bracket 31 beyond the sides of the boom 23 . The tips of the left and right boom cylinders 25 are aligned with the left and right ends of the boss 33, and the pins P12 are passed through the left and right boom cylinders 25 and the boss 33 to prevent the boom cylinders 25 from coming off. are rotatably connected to each other.

As shown in FIGS. 7 and 8, the boss 33 includes a relatively thick thick portion 33a and a relatively thin thin portion 33b. The thickness of the thin portion 33b is thinner than that of 33a). Two thick portions 33a are present on the left and right (longitudinal direction of the boss 33), and one thin portion 33b is interposed between the thick portions 33a. In this embodiment, the thick portion 33a and the thin portion 33b are manufactured separately and joined together by welding to form one boss 33. As shown in FIG. In this embodiment, the thick portion 33a and the thin portion 33b have the same outer diameter, and the inner diameter of the thin portion 33b is larger than the inner diameter of the thick portion 33a. Therefore, a gap G is interposed between the inner peripheral surface of the thin portion 33b and the outer peripheral surface of the pin P12, and the pin P12 is not in contact with the thin portion 33b. The thin portion 33b is positioned between the left and right arm brackets 32, and its length (left and right dimension) is equal to or less than the interval between the left and right arm brackets 32. As shown in FIG. Both the left and right arm brackets 32 and the left and right boom brackets 31 are supported by thick portions 33a. In particular, in this embodiment, the length of the thin portion 33b is set to about the interval between the left and right arm brackets 32, and the left and right arm brackets 32 are supported by the opposing ends of the left and right thick portions 33a.

The reinforcing plate 34 is a rectangular steel plate that connects the boom 23 and the boss 33 . It exists on both sides of the direction (that is, 6 sheets). One end of each reinforcing plate 34 is fixed to the outer peripheral surface of the boss 33, and the other end is fixed to the lower surface 23a of the boom 23. When viewed from the left and right, they are arranged in a V shape with the boss 33 as the apex. Left and right edges of each reinforcing plate 34 are joined to the opposing boom bracket 31 or arm bracket 32 . In this manner, each reinforcing plate 34 is fixed on four sides to the boss 33, the lower surface 23a of the boom 23, and the boom bracket 31 or the arm bracket 32. Contributing.

-effect-
(1) When the arm cylinder is arranged below the boom as in the present embodiment, if the tip of the arm cylinder is farther than necessary from the fulcrum of the arm (corresponding to pin P2), the arm may be displaced relative to the stroke of the arm cylinder. Decreased range of motion. In this case, the performance of the working device cannot be sufficiently exhibited.

In contrast, in this embodiment, the arm bracket 32 that supports the base end of the arm cylinder 26 is arranged between the boom brackets 31 that connect the tip end of the boom cylinder 25 so that they partially overlap in the longitudinal direction of the boom. laid out in As a result, the pins P12 and P13 supporting the distal end of the boom cylinder 25 and the proximal end of the arm cylinder 26 can be brought close to each other. In other words, it is possible to secure an adjustment allowance for the connection position (pin P14) of the tip of the arm cylinder 26 with respect to the fulcrum (pin P2) of the arm 24 by allowing the pin P13 to approach the pin P12. As a result, the tip (pin P14) of the arm cylinder 26 can be sufficiently brought close to the fulcrum (pin P2) of the arm 24 while considering the moment load when the arm 24 is driven. Therefore, together with the fact that the arm cylinder 26 is arranged on the lower side, it is possible to improve the performance of the working device 20 as a cargo handling device.

In addition, the boss 33 supporting the tip of the boom cylinder 25 penetrates not only the boom bracket 31 but also the arm bracket 32 . As a result, the pins P12 and P13 can be brought closer to each other without difficulty as compared with the case where the boom bracket 31 supports only the boom cylinder 25 and the arm bracket 32 supports only the arm cylinder 26 . Furthermore, the bosses 33 pass through the boom bracket 31 and the arm bracket 32, and by connecting these four brackets with the bosses 33, the rigidity of the bracket structure can be increased, and the right and left sides of each bracket on which a high load acts can be increased. It is possible to suppress tilting and deformation in the direction.

As described above, according to the present embodiment, in the configuration in which the boom cylinder 25 and the arm cylinder 26 are arranged below the boom 23, a wide movable range of the arm 24 can be secured with respect to the stroke of the arm cylinder 26. It is possible to improve the support strength of the cylinder.

(2) In order to support the pins P12 that support the two boom cylinders 25, the boss 33 must have a suitable length. get expensive. On the other hand, since the boss 33 includes the thin portion 33b, the manufacturing cost of the boss 33 can be suppressed. Even if the central portion in the longitudinal direction is the thin portion 33b, the support strength of the pin P12 by the boss 33 can be sufficiently secured.

(3) Simply focusing on the manufacturing cost of the boss 33, it is advantageous to shorten the thick portion 33a as much as possible. However, in this embodiment, the boss 33 serves as a support member for the arm bracket 32, so the thick portion 33a extends from the end of the boss 33 to the arm bracket 32. As shown in FIG. By supporting the arm bracket 32 with the thick portion 33a of the boss 33 in this way, the rigidity of the arm bracket 32 can be further increased. Further, since the boss 33 is passed through the arm bracket 32, the reaction force of the arm cylinder 26 can be transmitted to the boss 33 via the arm bracket 32, and the thick portion 33a can receive the reaction force.

(4) Furthermore, by providing a gap G between the pin P12 and the thin portion 33b interposed between the left and right thick portions 33a, a region not restrained by the boss 33 is secured in the center portion of the pin P12. be able to. Since the pin P12 is long, it may be bent when a high load acts on it during work. Thus, the load on pin P12 can be reduced.

(5) Since the arm bracket 32 is supported by the end of the thick portion 33a of the boss 33, the length of the thin portion 33b of the boss 33 between the left and right arm brackets 32 can be secured as much as possible. . This makes it possible to obtain the above effect (3) while minimizing the cost of the boss 33 .

(6) Since the pin P13 and the boom bracket 31 are configured so that they do not overlap when viewed from the left and right (the direction of inserting and removing the pin P13), the pin P13 can be inserted and removed from the left and right without interfering with the boom bracket 31, which improves efficiency. The arm cylinder 26 can be detached and attached well.

(7) By providing the reinforcing plate 34, the strength of the boom bracket 31 and the arm bracket 32 can be further improved.

DESCRIPTION OF SYMBOLS 10... Working machine main body 20... Working apparatus 22... Attachment 23... Boom 23a... Lower surface of boom 24... Arm 25... Boom cylinder 26... Arm cylinder 31... Boom bracket 32... Arm bracket 33 Boss 33a Thick portion 33b Thin portion 34 Reinforcing plate G Gap P12 Pin (first pin) P13 Pin (second pin)

Claims (6)

A work machine body and a work device attached to the work machine body, wherein the work device includes a boom rotatably connected to the work machine body, an arm rotatably connected to the boom, and the It comprises an attachment attached to an arm, two boom cylinders for driving the boom, and an arm cylinder for driving the arm, and the boom cylinder and the arm cylinder are arranged below the boom. In a working machine that has been
a first pin that supports the tip of the boom cylinder;
a second pin that supports the proximal end of the arm cylinder;
a boss supporting the first pin;
left and right boom brackets provided on the lower surface of the boom to support the boss;
Left and right arm brackets provided on the lower surface of the boom and supporting the second pin,
The left and right arm brackets are interposed between the left and right boom brackets, and the boom bracket and the arm bracket are arranged to partially overlap when viewed from the left and right ,
an end portion of the arm bracket on the boom tip side protrudes from the boom bracket toward the boom tip side, and the second pin is supported by the protruding portion ;
a base end of the arm cylinder is inserted between the left and right arm brackets, and the left and right arm brackets and the base end of the arm cylinder are connected by the second pin;
The boss penetrates the left and right boom brackets and the left and right arm brackets, the tips of the two boom cylinders are positioned at the left and right ends of the boss, and the two boom cylinders and the boss are attached to the second boom bracket. A working machine characterized by having one pin through it . The work machine according to claim 1,
The boss includes left and right thick-walled portions having a relatively thick wall thickness and thin-walled portions having a relatively thin wall thickness and connecting the left and right thick-walled portions, and
A working machine, wherein both the left and right arm brackets and the left and right boom brackets are supported by the thick portion. 3. A working machine according to claim 2, wherein said left and right arm brackets are respectively supported by opposing ends of said left and right thick portions. 4. The working machine according to claim 3, wherein the thin portion of the boss has a larger inner diameter than the thick portion, and a gap is interposed between the thin portion and the first pin. machine. 2. The work machine according to claim 1, wherein the second pin does not overlap the boom bracket when viewed from the left and right, and the second pin is configured to be removable and insertable to the left and right without interfering with the boom bracket. A working machine characterized by: 2. A working machine according to claim 1, further comprising a reinforcing plate connecting said boom and said boss.

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