JP4798228B2 - Work machine boom - Google Patents

Description

  The present invention relates to a boom equipped as a work attachment on a work machine such as a dismantling machine.

  2. Description of the Related Art Conventionally, there is known a boom for a work machine that includes a main boom that is supported by an upper swing body of the work machine so as to be raised and lowered, and that can be detached from the main boom.

  For example, in a work machine such as Patent Document 1, the base end side of an intermediate boom is inserted between a pair of side plates of a lower boom, which is a main boom, and connected by a connecting pin. Similarly, the base end side of the upper boom (second boom) is inserted between a pair of side plates of the intermediate boom (first boom) at the front end and connected by a connecting pin.

Specifically, as shown in FIGS. 8 and 9, in the conventional work machine, the base end side of the second boom 108 is inserted between the pair of side plates 120 of the first boom 106, and the connection pin 122 is connected. The cylinder mounting portion 126 that rotatably supports the boom cylinder 111 that bends and stretches the second boom 108 and the third boom (not shown) has a highly rigid closed cross-section structure (box structure). 108 is provided on the abdominal surface side.
Utility Model Registration Gazette No. 2535667

  However, there may be a case where the size of the work machine is small and space is not taken up in the configuration, or because of the attachment / detachment configuration, the base end side of the second boom cannot be inserted between the pair of side plates of the first boom.

  In such a case, it is necessary to insert the tip of the first boom between the side plates of the second boom, and it is difficult to provide the cylinder mounting portion on the second boom in terms of space and rigidity.

  The present invention has been made in view of such a point, and the purpose of the present invention is that even if the base end side of the second boom cannot be inserted between the pair of side plates of the first boom, An object of the present invention is to provide a cylinder mounting portion on the second boom while maintaining rigidity.

  In order to achieve the above object, in the present invention, a cylinder mounting portion is provided on a rigid member that connects a pair of side plates of the second boom.

Specifically, in the first invention,
At least first, second, and third booms are provided, and the base end side of the first boom is pivotally attached to the work machine body by a first boom base end pin so as to be swingable in the vertical direction. A working machine configured such that a distal end side and a second boom are coupled, and the second boom and the third boom are connected to each other so as to be relatively rotatable about a horizontal axis, and the boom cylinder performs a bending operation. Targeting the boom.

And the second boom is
A pair of side plates that sandwich the tip of the first boom from both sides in the horizontal direction on the base end side;
A rigid member for connecting the pair of side plates in the horizontal direction;
A closed cross section surrounded by the rigid member and the side plate;
A horizontal axis insertion portion formed in the pair of side plates, through which the horizontal axis is inserted;
A connection pin insertion portion formed in the pair of side plates, through which a connection pin for connecting the first boom is inserted;
A side plate extension portion extended from the connecting pin insertion portion to the side opposite to the horizontal axis on the pair of side plates;
A cylinder mounting portion formed in the side plate extension, through which a cylinder support pin that rotatably supports one end of the boom cylinder is inserted;
With
At least a part of the cylinder support pin is disposed closer to the first boom proximal pin than the closed cross-section in a direction along a straight line connecting the first boom proximal pin and the horizontal shaft insertion portion in a side view. Has been.

According to the above configuration, the base end side of the second boom can be inserted between the pair of side plates of the first boom when the size of the work machine is small and the space for the configuration cannot be taken. Even if it is difficult to dispose the cylinder support pins, the pair of side plates of the second boom sandwich the tip of the first boom from both sides in the horizontal direction and connect the pair of side plates in the horizontal direction with a rigid member. The rigid member and the pair of side plates form a closed cross section to ensure rigidity. Moreover, since the load at the time of cylinder expansion and contraction applied to the boom cylinder is supported by the side plate extension portion obtained by extending the side plate, the necessary strength is ensured even in a limited space. Furthermore, since the cylinder mounting portion is provided on the second boom, the second and third booms can be separated from the first boom while the boom cylinder is connected. “At least a part of the cylinder support pin” is a direction along a straight line connecting the first boom base end pin and the horizontal shaft insertion portion in a side view, and the distance from the horizontal shaft insertion portion is closed with the cylinder support pin. It means that there may be an equal part in the cross section.

In the second invention, in the first invention,
The cylinder mounting portion is connected to a side plate connecting portion that connects the left and right side plate extensions, and the side plate connecting portion is configured to receive at least a part of a load applied to the boom cylinder.

  According to the above configuration, since at least a part of the load applied to the boom cylinder is received by the side plate connecting portion and this load is transmitted to the side plate extension portion, the necessary strength is effectively ensured in a limited space.

In the third invention, in the first or second invention,
The rigid member is
A rigid member body for connecting the pair of side plates between the horizontal axis insertion portion and the connection pin insertion portion;
A rigid member extension extending from the rigid member body and connecting the pair of side plates extending to the ventral side of the first boom;
Have
The rigid member body constitutes a part of the closed cross section,
The rigid member extension portion constitutes the side plate connecting portion,
The cylinder mounting portion is connected across the closed cross-section portion and the rigid member extension portion.

  According to said structure, a part of load concerning a cylinder attaching part is transmitted also to a closed cross-section part via a rigid member extension part.

In the fourth invention, in the third invention,
A second closed cross-sectional portion different from the closed cross-sectional portion is formed on the side plate extension portion on the opposite side of the cylinder mounting portion.

  According to said structure, the rigidity of the cylinder attaching part which is easy to apply a load further improves by the 2nd closed cross-section part.

In a fifth invention, in any one of the first to fourth inventions,
The first boom is a main boom supported by the upper swing body of the work machine so as to be raised and lowered,
The second boom is a main front boom connected to the main boom.

  According to the above configuration, even when the space is limited, such as a small work machine, the configuration of the boom of the work machine that can replace the upper side of the main boom with the boom cylinder attached to the cylinder mounting portion Is possible.

As described above, according to the present invention, in the second boom, the pair of side plates into which the front ends of the first boom are inserted are connected by the rigid members, and one end of the boom cylinder is rotated around the side plate extension portion that extends the side plate. A cylinder mounting portion is provided that is movably supported , and at least a part of the cylinder support pin in a direction along a straight line connecting the first boom base end pin and the horizontal shaft insertion portion in a side view, than the closed cross section. In the limited space where the base end side of the second boom cannot be inserted between the pair of side plates of the first boom due to the arrangement on the end pin side , the side plate is connected to the horizontal axis in the axial direction of the boom cylinder. The cylinder mounting portion can be provided on the second boom while ensuring the degree of freedom to inflate to the opposite side and maintaining rigidity.

  According to the second aspect of the present invention, the cylinder mounting portion is connected to the side plate connecting portion, and at least a part of the load applied to the boom cylinder is received by the side plate connecting portion, thereby ensuring the necessary strength with a simple configuration. Therefore, the cylinder mounting portion can be effectively arranged even in a limited space.

  According to the third aspect of the invention, the rigid member extension portion functions as the side plate connecting portion, and the load applied to the boom cylinder is also transmitted to the rigid member, so that the cylinder mounting portion is more effectively provided in a limited space. Can be arranged.

  According to the fourth aspect, by forming the second closed cross section in the side plate extension, it is possible to more effectively support the load applied to the boom cylinder even in a limited space.

  According to the fifth aspect, the first boom is the main boom of the work machine and the second boom is the main front boom, so that even a small work machine can be easily replaced and has a high strength boom. can do.

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

  FIG. 2 shows a hydraulic excavator 1 as a work machine provided with a boom of the work machine according to an embodiment of the present invention. The hydraulic excavator 1 includes a lower traveling body 3 having a crawler 2, and the lower traveling body 3. And an upper revolving body 4 that is rotatably supported.

  A boom foot 5 of the upper swing body 4 has a main boom cylinder 7 that is raised and lowered around a lower end of a main boom 6 as a first boom and a boom foot pin 5a as a first boom base end pin. The lower end is supported. As shown in FIGS. 1, 3, and 4, a hook pin 6 a for hooking the proximal end side of the main front boom 8 when the main front boom 8 is attached protrudes in the horizontal direction on the main boom 6. Is provided. Further, a boss portion 6 b for inserting a cylinder pin 7 a that supports the upper end of the main boom cylinder 7 bulges horizontally on the main boom 6.

  Various booms can be connected to the tip of the main boom 6. In this embodiment, the main front boom 8 as the second boom is coupled so as not to rotate. An intermediate boom 9 as a third boom is coupled to the tip of the main front boom 8 so as to be relatively rotatable around a boom connection pin 10 as a horizontal axis, and is configured to bend and extend by a boom cylinder 11. ing.

  As shown in FIG. 2, the lower end of the arm cylinder 12 is rotatably connected to the back side of the intermediate boom 9. The base end side of the arm 13 is rotatably supported at the tip end of the intermediate boom 9, and the upper end of the arm cylinder 12 is rotatably connected to the base end side of the arm 13, thereby The arm 13 is connected so as to be relatively rotatable.

  The proximal end side of the bucket 14 is rotatably connected to the distal end of the arm 13, and a bucket link 16 is connected to the proximal end side of the bucket 14 and the distal end side of the arm 13, and the bucket cylinder 15 is connected to the bucket link 16. The tips of are connected. Thus, the bucket 14 is connected to the arm 13 so as to be rotatable relative to the arm 13.

  As shown in FIGS. 1, 3, and 4, the main front boom 8 includes a pair of side plates 20 that sandwich the tip of the main boom 6 from both sides in the horizontal direction on the base end side. The side plate 20 has a boss-like horizontal shaft insertion portion 20a having a through hole, and a boom connection pin 10 connected to the intermediate boom 9 is inserted into the pair of left and right horizontal shaft insertion portions 20a. Further, the side plate 20 has a pair of connecting pin insertion portions 20b through which the connecting pins 22 for connecting the main boom 6 are inserted. The horizontal axis insertion portion 20a and the pair of connecting pin insertion portions 20b are arranged in a triangular shape in a side view. A hook-like hook 20c is formed at the end of the pair of side plates 20 opposite to the horizontal shaft insertion portion 20a (on the main boom 6 side) so as to be hooked on the hook pin 6a. Moreover, the main boom 6 side edge part of a pair of side plate 20 is cut | disconnected so that it may be rounded so that the boss | hub part 6b of the main boom 6 may be continued following the hook 20c. As shown only in FIG. 1, the boom connection pin 10 and the coupling pin 22 have rotation prevention members 10 a and 22 a, respectively, and the rotation prevention members 10 a and 22 a protrude from the surface of the main front boom 8. The rotation is stopped by 8a.

  A rigid member 23 that connects the pair of side plates 20 in the horizontal direction is welded to a region surrounded by the horizontal shaft insertion portion 20a and the pair of connection pin insertion portions 20b. The rigid member 23 includes a rigid member main body 23a that connects the pair of side plates 20 between the horizontal shaft insertion portion 20a and the connection pin insertion portion 20b, and a pair of the rigid member main body 23a that extends from the rigid member main body 23a and that is on the abdominal surface side of the main boom 6. And a rigid member extension 23b for connecting the side plates 20 to each other. The rigid member main body 23a and the rigid member extension 23b may be formed by bending a single steel plate or welded to each other.

  A first reinforcing plate 23c having both ends bent toward the pair of connecting pin insertion portions 20b is welded to the horizontal shaft insertion portion 20a side of the rigid member main body 23a. The first reinforcement plate 23c, the rigid member main body 23a, and a pair A closed section 25 is formed in a region surrounded by the side plate 20.

  The rigid member extension 23b extends from the rigid member main body 23a in a direction away from the horizontal axis insertion portion 20a so as to bypass the ventral connection pin insertion portion 20b, and then bends in a direction away from the connection pin insertion portion 20b. It extends. A cylinder mounting portion 26 is welded to the rigid member extension 23b and the first reinforcing plate 23c. The cylinder mounting portion 26 includes a pair of rib portions 26a that are continuously welded across the rigid member extending portion 23b and the first reinforcing plate 23c at a distance in the horizontal direction, and each rib portion 26a has a boss portion. 26b is formed. A cylinder support pin 27 that rotatably supports one end (the tube side in the present embodiment) of the boom cylinder 11 is inserted into the boss portion 26b.

And in this embodiment, as shown in FIG. 3, at least one part of the cylinder support pin 27 followed the straight line which connects the boom foot pin 5a of the main boom 6 base end and the horizontal axis insertion part 20a by side view . It is arrange | positioned by the direction at the main boom 6 side (boom foot pin 5a side) rather than the closed cross-section part 25. That is, when the boom foot pin 5a is viewed from the horizontal shaft insertion portion 20a, there may be a portion where the distance is equal between the cylinder support pin 27 and the closed cross-section portion 25, but at least a part of the cylinder support pin 27 is closed. What is necessary is just to be in the main boom 6 side (boom foot pin 5a side) rather than the cross-sectional part 25. FIG. This arrangement is achieved by inflating the side plate 20 rearward to form the side plate extension 21.

  The load applied to the cylinder mounting portion 26 is transmitted to the side plate extension portion 21 via the rigid member extension portion 23 b and is transmitted to the connecting pin 22. A part of the load is also transmitted to the closed cross section 25.

  Further, a second reinforcing plate 23d bent in a V shape in a side view is welded to the opposite side of the rigid member extension 23b to the cylinder mounting portion 26, and the second reinforcing plate 23d and the pair of side plates 20 are rigid. A second closed section 29 is formed by the member extension 23b. The second closed cross-section portion 29 further improves the rigidity of the cylinder mounting portion 26 that is easily loaded. The shape of the rigid member extension 23b may be a U shape or a semicircular shape in a side view, and is not limited to a V shape.

  With the above configuration, the upper side of the main boom 6 can be replaced by removing the main front boom 8 while the boom cylinder 11 is attached to the cylinder mounting portion 26. The excavator 1 can be replaced not only with a bucket boom as in the present embodiment but also with a plurality of types of booms such as an ultra-long attachment and a separate boom, for example.

  Therefore, in the present embodiment, the base end side of the main front boom 8 is inserted between the pair of side plates 20 of the main boom 6 when the size of the work machine is small and the space for the configuration cannot be taken, or due to the configuration of detachment. Even if this is not possible, the pair of side plates 20 of the main front boom 8 sandwiches the front end of the main boom 6 from both sides in the horizontal direction, and the pair of side plates 20 are connected in the horizontal direction by the rigid members 23 so that the rigid members 23 and the pair of side plates 20 form a closed section 25 to ensure rigidity and support the cylinder mounting portion 26 on the side plate extension 21 that extends the side plate 20, so in a limited space, To effectively support the load applied to the cylinder support pin 27 by ensuring the degree of freedom of inflating the side plate 20 in the direction of the axis of the boom cylinder 11 in the direction opposite to the boom connection pin 10. It can be.

-Modification 1 of embodiment-
FIG. 6 shows a first modification of the embodiment of the present invention, which differs from the above embodiment mainly in that the rigid member extension 23b is not provided. In the following embodiments, the same portions as those in FIGS. 1 to 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this modification, the rigid member 123 consists only of a portion corresponding to the rigid member main body 23a of the above-described embodiment, and the closed cross-section portion 25 is formed by this portion and the first reinforcing plate 23c.

  The side plate extension portion 21 is welded with a side plate connecting portion 125 made of a round pipe extending left and right.

  A pair of left and right rib portions 126a are welded to the side plate connecting portion 125, and a boss portion 126b is formed on each rib portion 126a. A cylinder mounting portion 126 is constituted by the rib portion 126a and the boss portion 126b. One end of the boom cylinder 11 is inserted between the boss portions 126b, and the cylinder support pin 27 is inserted.

  With such a configuration, at least a part of the load applied to the boom cylinder 11 is received by the side plate connecting portion 125. Then, this load is transmitted to the side plate extension 21 and is transmitted to the connecting pin 22.

  Therefore, also in this modification, the required strength is effectively ensured in a limited space.

-Modification 2 of embodiment-
FIG. 7 shows a second modification of the embodiment of the present invention, which is different from the first modification in that the side plate connecting portion 225 is formed of a square pipe.

  Also in this modification, the cylinder mounting part 226 is comprised by the rib part 226a and the boss | hub part 226b, and required intensity | strength is effectively ensured in the limited space similarly to the modification 1. FIG.

—Modification 3 of Embodiment—
Although not shown in detail, the boss portion may be welded directly to the side plate extension portion 21 to transmit the load applied to the boom cylinder 11 to the side plate extension portion 21 in order to cause the boss portion to function as the side plate connecting portion. Even in this case, the required strength is effectively ensured in a limited space as in the first and second modifications.

(Other embodiments)
The present invention may be configured as follows with respect to the above embodiment.

  That is, in the above embodiment, the first boom is the main boom 6, the second boom is the main front boom 8, and the third boom is the intermediate boom 9. However, the present invention is not limited to such a boom configuration. One boom may be a joint boom connected to the main boom, a backhoe type with the bucket 14 facing upward may be connected to the tip of the boom, or a crusher may be connected. The third boom may be an arm.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use.

It is a perspective view which expands and shows the main front boom of the boom of the working machine concerning embodiment of this invention, and its periphery. It is a side view showing the whole hydraulic excavator. It is an enlarged side view which shows a main front boom and its periphery. It is an enlarged bottom view which shows a main front boom and its periphery. It is a side view which expands and shows a main front boom. It is an enlarged side view which shows the main front boom and its periphery concerning the modification 1 of embodiment. It is an enlarged side view which shows the main front boom concerning the modification 2 of embodiment, and its periphery. It is a side view which shows the connection part of the boom of the working machine concerning a prior art. It is a bottom view which shows the connection part of the boom of the working machine concerning a prior art.

1 Excavator (work machine)
4 Upper swing body 6 Main boom (first boom)
8 Main front boom (second boom)
9 Intermediate boom (third boom)
10 Boom connection pin (horizontal axis)
DESCRIPTION OF SYMBOLS 11 Boom cylinder 20 Side plate 20a Horizontal axis insertion part 21 Side plate extension part 10a, 22a Anti-rotation member 22 Connection pin 23 Rigid member 23a Rigid member main body 23b Rigid member extension part (Side plate connection part)
23c 1st reinforcement board 23d 2nd reinforcement board 25 Closed cross-section part 26,126,226 Cylinder attachment part 27 Cylinder support pin 29 2nd closed cross-section part 125 Side plate connection part 225 Side plate connection part

Claims (5)

At least first, second, and third booms are provided, and the base end side of the first boom is pivotally attached to the work machine body by a first boom base end pin so as to be swingable in the vertical direction. A working machine configured such that a distal end side and a second boom are coupled, and the second boom and the third boom are connected to each other so as to be relatively rotatable about a horizontal axis, and the boom cylinder performs a bending operation. Boom,
The second boom is
A pair of side plates that sandwich the tip of the first boom from both sides in the horizontal direction on the base end side;
A rigid member for connecting the pair of side plates in the horizontal direction;
A closed cross section surrounded by the rigid member and the side plate;
A horizontal axis insertion portion formed in the pair of side plates, through which the horizontal axis is inserted;
A connection pin insertion portion formed in the pair of side plates, through which a connection pin for connecting the first boom is inserted;
A side plate extension portion extended from the connecting pin insertion portion to the side opposite to the horizontal axis on the pair of side plates;
A cylinder mounting portion formed in the side plate extension, through which a cylinder support pin that rotatably supports one end of the boom cylinder is inserted;
With
At least a part of the cylinder support pin is disposed closer to the first boom proximal pin than the closed cross-section in a direction along a straight line connecting the first boom proximal pin and the horizontal shaft insertion portion in a side view. The boom of the working machine characterized by being made. In the boom of the working machine according to claim 1,
The cylinder mounting portion is connected to a side plate connecting portion that connects the left and right side plate extensions, and the side plate connecting portion is configured to receive at least a part of a load applied to the boom cylinder. Boom of work machine. In the boom of the working machine according to claim 2,
The rigid member is
A rigid member body for connecting the pair of side plates between the horizontal axis insertion portion and the connection pin insertion portion;
A rigid member extension extending from the rigid member body and connecting the pair of side plates extending to the ventral side of the first boom;
Have
The rigid member body constitutes a part of the closed cross section,
The rigid member extension portion constitutes the side plate connecting portion,
The boom of a working machine, wherein the cylinder mounting portion is connected across the closed cross-section portion and the rigid member extension portion. In the boom of the working machine according to claim 3,
A boom of a working machine, wherein a second closed cross-section portion different from the closed cross-section portion is formed on the side plate extension portion on the opposite side of the cylinder mounting portion. In the boom of the working machine according to any one of claims 1 to 4,
The first boom is a main boom supported by the upper swing body of the work machine so as to be raised and lowered,
The boom of a working machine, wherein the second boom is a main front boom coupled to the main boom.

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