JP5939343B2 - Work machine boom - Google Patents

Description

  The present invention relates to a split-type boom equipped in a work machine that performs dismantling work or the like.

  2. Description of the Related Art Conventionally, a work machine such as a demolition machine that performs a building demolition work is used with an ultralong attachment attached to a base machine. Such an ultra-long attachment is used for building demolition and the like, and is a very long part. Therefore, it may be difficult to transport the attachment if the attachment is integrated. In addition, it may be preferable from the viewpoint of work that the attachment can be partially recombined according to the purpose of the work, the work height, or the like.

  Then, like the dismantling machine of patent document 1, the dismantling machine provided with the division | segmentation type boom which is a boom of an attachment and can be divided | segmented about the longitudinal direction is proposed.

  In a conventional split boom, two or more boom bodies are arranged in a straight line, and the boom bodies are pin-coupled to each other. Specifically, one of the two adjacent boom bodies has a pair of side walls that protrude from the main body toward the other boom body and can hold the other boom body from the side. And the other boom body includes a plurality of bosses that are pin-coupled together with the side walls. Boom bodies can be connected by inserting the other boom body between a pair of side walls provided on one boom body and inserting pins into a plurality of bosses through through holes formed in the side walls. Is possible.

  Since the side walls are easily subjected to a load such as a bending load applied to the attachment during work in a state where the boom bodies are connected to each other, a wide range of the side walls is made of thick steel plates in order to ensure the strength and rigidity of the side walls. ing.

Japanese Patent Laid-Open No. 9-3955

  However, in order to ensure the strength and rigidity of the side wall, a wide range of the side wall is made of a thick steel plate, so it is difficult to reduce the weight of the side wall. Moreover, since the number of boom bodies connected to each other increases as the attachment becomes longer, the influence of the increase in the weight of the side wall becomes even greater, and it becomes more difficult to reduce the weight of the boom. Furthermore, since the wide range of the side wall is constituted by the thick steel plate, there is a problem that it is difficult to suppress the manufacturing cost.

  In recent years, a fixed shaft such as a fixing pin is attached to the rear end portion of the other boom body in order to connect the side wall of one boom body to the other boom body in order to speed up the connecting operation between the boom bodies. A structure is proposed in which a notch that can be engaged with the fixed shaft is formed on the side wall and the labor of inserting and removing the pin is reduced by engaging the fixed pin with the notch. Has been.

  However, in such a structure, the portion where the notch is formed in the side wall is more likely to deform due to the inner wall of the notch being opened and deformed more easily than the case where the pin hole is formed, and local stress concentration is likely to occur. There is a problem that the side wall is easily damaged. Therefore, in order to improve the rigidity of the side wall having a notch, it is necessary to configure a wide range of the side wall with a thick steel plate, and there is a problem that it is difficult to reduce the weight and suppress the manufacturing cost.

  The present invention has been made to solve the above-described problems, and provides a boom for a working machine that can reduce the weight of a side wall of a split boom and can reduce labor in assembly work. .

The boom of the work machine according to the present invention includes a first boom body and a second boom body disposed at an end portion in the longitudinal direction of the first boom body, and the first boom body includes: An upper plate, a lower plate, and left and right side plates, and the upper plate, the lower plate, and the left and right side plates constitute a first closed cross section, and a closed cross section component on both sides of the closed cross section component. A pair of side walls respectively provided so as to protrude in the longitudinal direction of the closed cross-section component along the side plate, and a second side wall projecting in the longitudinal direction of the closed cross-section component and covered laterally by the pair of side walls. A projecting portion projecting in a longitudinal direction of the closed section constituting portion, and an end portion in the projecting direction of the projecting portion, and Removably engaged with the end of the boom body in the longitudinal direction A first engaging portion capable of being detachably engaged with a longitudinal end portion of the second boom body, which is disposed at a position lower than the projecting portion and closer to the closed cross-section component. An engaging portion, the first engaging portion has a notch engageable with an end portion in a longitudinal direction of the second boom body, and the projecting portion protrudes from the protruding portion. Rutotomoni that Yusuke from the upper edge parts of the portions which are configured to a range of up to the lower edge, a shape protruding forward so as to have a distal end between said first engaging portion and the second engagement portion Have.

  According to the present invention, the first engaging portion of the first boom body is arranged so as to protrude in the longitudinal direction of the closed cross-section constituent part from the second engaging portion, thereby facilitating the workability of the connecting work between the boom bodies. In the above structure, the side wall is lightened by reinforcing the first engaging portion with the overhanging portion. According to such a configuration, when connecting the first boom body and the second boom body, the first engagement portion and the second engagement portion included in the pair of side walls of the first boom body cause the second Engaged with the end of the boom body in the longitudinal direction. First, the first boom body is moved, and the notch of the first engaging portion provided at the end portion of the protruding portion in the protruding direction of the protruding portion protruding in the longitudinal direction of the closed cross-section constituent portion of the side wall is moved. The second boom body is engaged with the end portion in the longitudinal direction. Then, the boom bodies are connected to each other by engaging the second engaging portion located below the projecting portion and closer to the closed cross-section component part with the end of the second boom body in the longitudinal direction by pin coupling or the like. It is possible to work easily.

  Moreover, since the overhang | projection part has the part comprised in the range extended from the upper edge of a protrusion part to a lower edge, the protrusion part of the side wall in which the 1st engaging part which has a notch was provided is concentrated. It is possible to reinforce. Therefore, it is possible to reduce the possibility that the inner wall of the notch opens and deforms. As a result, even in a side wall having a notch where stress concentration is likely to occur, the thickness of the side wall can be reduced by thinning a material such as a steel plate used for the side wall while ensuring rigidity and strength of the side wall. In addition, the side wall can be reduced in weight and thickness, so that the manufacturing cost can be reduced.

  It is preferable that the tip of the protruding portion in the protruding direction is positioned forward in the protruding direction with respect to a straight line connecting the first engaging portion and the second engaging portion.

  According to such a configuration, both side ends of the overhang portion are coupled to a range between the first engagement portion and the second engagement portion that are likely to receive a load from the second boom body on the side wall. It is possible to reinforce. In addition, since the overhanging portion is coupled to the side walls on both sides near the first and second engaging portions and the side walls on both sides are integrated, the support rigidity of the side walls can be improved.

  Furthermore, it is preferable that a tip of the protruding portion in the protruding direction is disposed at a position closer to the first engaging portion than the second engaging portion.

  According to such a configuration, the overhang portion can be disposed closer to the first engagement portion having the notch, and the portion in the vicinity of the notch in the side wall can be reinforced intensively by the overhang portion. Become. Therefore, it is possible to further reduce the risk of the inner wall of the notch opening and deforming.

  Further, the overhanging portion further includes a longitudinally extending portion obtained by extending the upper plate in the longitudinal direction of the closed cross-section constituent portion, and is configured in a range extending from the upper edge to the lower edge of the protruding portion. The portion is continuous from the distal end side end portion of the longitudinally extending portion to the distal end in the protruding direction of the overhanging portion, and the distal end side end portion of the longitudinally extending portion is more than the second engaging portion. It is preferable that it is arrange | positioned in the front position in the protrusion direction.

  According to such a configuration, not only the front end in the protruding direction in the overhanging portion but also the front end side end portion of the longitudinal extension portion obtained by extending the upper plate in the longitudinal direction of the closed cross-section constituent portion has a notch. It is possible to place the first engagement portion that is configured in a range extending from the upper edge to the lower edge of the projecting portion between the distal end side end portion and the distal end in the projecting direction. It becomes possible to come closer to the part. As a result, it becomes possible to reinforce a more extensive portion of the overhang portion closer to the portion in the vicinity of the notch in the side wall, thereby further reducing the possibility that the inner wall of the notch will open and deform. It becomes possible.

  Furthermore, it is preferable that the second boom body has a recessed portion that is recessed in the longitudinal direction of the second boom body at the end portion in the longitudinal direction and that can accommodate the projecting portion.

  According to such a configuration, the projecting portion of the end portion in the longitudinal direction of the first boom body can enter the recessed portion of the end portion in the longitudinal direction of the second boom body, and in the joint portion between the boom bodies. It is possible to improve the rigidity. Further, by absorbing the protruding amount by the projecting portion by the recessed portion, it is possible to suppress an increase in the dimension of the boom bodies in the longitudinal direction at the joint portion between the boom bodies.

  Furthermore, it is preferable that the second engaging portion is disposed in a direction from the opening in the notch toward the back end with respect to the first engaging portion.

  According to such a configuration, in the state where the longitudinal end portion of the second boom body is engaged with the notch of the first engaging portion, the second engaging portion is the longitudinal end portion of the second boom body. By engaging with the second engagement portion, the movement of the end portion in the longitudinal direction of the second boom body from the back end of the notch of the first engagement portion toward the opening can be reliably restricted by the second engagement portion. Is possible.

  According to the present invention, it is possible to reduce the weight of the side wall of the split boom, and to reduce labor in assembling work.

It is a schematic side view of the state which extended and started up the attachment of the dismantling machine with a super-long attachment concerning the embodiment of the dismantling machine of the present invention. It is a schematic side view of the state which folded the attachment of the demolition machine of FIG. It is a front view of the insert boom of the attachment of FIG. It is a top view of the insert boom of FIG. FIG. 5 is a sectional view taken along line VV in FIG. 4. It is an enlarged view of the overhang | projection part of FIG. FIG. 3 is a cross-sectional view showing a state before connecting the insert booms in a folded state of the attachment of FIG. 2. FIG. 3 is a plan view showing a state before the insert booms are connected to each other in the folded state of the attachment of FIG. 2. It is a bottom view which shows the state before connecting insert booms in the state which the attachment of FIG. 2 was folded. It is sectional drawing which shows the state after connecting the insert booms of FIG. It is a top view which shows the state after connecting the insert booms of FIG. It is a bottom view which shows the state after connecting the insert booms of FIG. It is a front view of the main boom of the attachment of FIG. It is a longitudinal cross-sectional view of the main boom of FIG. It is a perspective view of the main boom of FIG.

  In the following embodiment, as an embodiment of the working machine of the present invention, the dismantling machine 1 with an ultralong attachment is applied as a subject of description of the background art.

  The demolition machine 1 of this embodiment is comprised from the base machine 2 and the work attachment 3, as FIG. The base machine 2 includes a crawler-type lower traveling body 4 and an upper revolving body 5 that is mounted on the lower traveling body 4 so as to be rotatable about a vertical axis. The work attachment 3 is attached to the front part of the base machine 2.

  The work attachment 3 includes a boom 6 attached to the base machine 2 (upper turning body 5) so as to be able to move up and down, and a short inter boom attached to the tip of the boom 6 so as to be rotatable about a horizontal axis in the vertical direction. 7, an arm 8 whose rear end portion is attached to the front end of the inter boom 7 so as to be pivotable in the vertical direction around a horizontal axis, and a crushing device 9 such as a nibler attached to the front end portion of the arm 8. It is equipped with.

  The boom 6 includes a plurality of boom bodies, that is, a main boom 6a, a front boom 6b, and insert booms 6c1 and 6c2. The main boom 6 a constitutes a portion on the base side of the boom 6, and is attached to the upper swing body 5 so as to be raised and lowered. The front boom 6b constitutes a portion on the tip side of the boom 6, and the inter boom 7 is rotatably attached to the tip portion. The insert booms 6c1 and 6c2 are interposed between the main boom 6a and the front boom 6b, and the length of the boom 6 can be extended to a length suitable for the dismantling work.

  The front boom 6b, the insert boom 6c1, the insert boom 6c2, and the main boom 6a are connected in a straight line in that order to constitute a long boom 6.

  1-2, as a cylinder for operating the work attachment 3, a boom cylinder 10 for raising and lowering the boom 6 (the entire attachment 3), an inter boom cylinder 11 for operating the inter boom 7, and an arm 8 And a crushing device cylinder 13 for rotating the crushing device 9 about the horizontal axis.

As shown in FIG. 2, when the work attachment 3 is folded and transported, the attachment 3 is folded in a three-fold state with the front boom 6b on the upper side and the arm 8 on the lower side with the inter boom 7 as a boundary. In other words, the base machine 2 and the main boom 6a are assembled, the work boom 3a excluding the main boom 6a and the insert boom 6c2, and the insert boom 6c2 are separated and transported. After transportation, they are assembled in the same state.

  In this work attachment 3, the insert boom 6c2 is separated from the insert boom 6c1 after being folded in a three-fold state as shown in FIG. 2, and then separated from the main boom 6a. When assembling, they are connected in the reverse order.

(Configuration of insert boom 6c2)
Here, the configuration of the insert boom 6c2 will be specifically described as an example of a plurality of boom bodies constituting the boom 6. Here, the insert boom 6c2 corresponds to the first boom body of the present invention, and the insert boom 6c1 connected to the distal end side of the insert boom 6c2 corresponds to the second boom body of the present invention. Furthermore, since the insert booms 6c1 and 6c2 have the same configuration as described below, the description of the configuration of the insert boom 6c1 is omitted in this embodiment. Further, the main boom 6a (see FIGS. 13 to 15) connected to the rear end side of the insert boom 6c2 is a front portion of the insert boom 6c2 (for example, a pair of front side walls 22, an overhang portion 26 and a pin support portion 25 described later). ) In common with the insert boom 6c2.

  As shown in FIGS. 3 to 5, the insert boom 6 c 2 includes a main body 20, a pair of front side walls 22, a pair of rear side walls 23, a fixing pin 24, and a pin support portion 25.

<Front side wall 22>
The pair of front side walls 22 protrudes in the longitudinal direction (forward in the present embodiment) of a closed cross-section component 21 of the main body 20 described later, and specifically, on the side plates 21c and 21d on both sides constituting the closed cross-section component 21. Along the front ends 21 c 1 and 21 d 1 of these side plates, the front plates 21 are arranged so as to protrude forward of the main body 20. The front side wall 22 corresponds to the side wall of the present invention.

  The front side wall 22 has a protruding portion 22b that protrudes forward. The protrusion 22b only needs to be configured above the pin hole 33, and the distance between the upper edge 22c and the lower edge 22d is not particularly limited in the present invention. Further, the front side wall 22 has a hook portion 30 and a pin attachment portion 31 as two engaging portions that can be detachably engaged with a rear end portion of the insert boom 6c1 provided on the front end side with respect to the insert boom 6c2. ing. The hook portion 30 corresponds to the first engagement portion of the present invention, and the pin attachment portion 31 corresponds to the second engagement portion of the present invention.

  5-6, the hook part 30 is provided in the edge part of the protrusion direction of the protrusion part 22b, and the front side edge part in this embodiment. The hook portion 30 has a notch 32 that can be engaged with the rear end portion of the insert boom 6c1 on the front end side (specifically, a fixing pin having the same shape as the fixing pin 24 in FIGS. 3 to 5). The inner wall near the back end 32b of the notch 32 has an arc shape. The hook portion 30 is disposed closer to the front end 22a in the protruding direction A of the front side wall 22 and closer to the upper plate 21a than the pin mounting portion 31 is. The opening 32 a of the notch 32 opens toward the front upper side of the front side wall 22. In the front side wall 22 of this embodiment, the periphery of the notch 32 is reinforced by partially overlapping steel plates.

  The pin mounting portion 31 is disposed below the projecting portion 22b and closer to the closed cross-section component 21 and in the rear position in this embodiment. The pin mounting portion 31 has a circular pin hole 33 formed through the front side wall 22. The pin hole 33 is disposed in the direction C from the opening 32 a in the notch 32 toward the back end 32 b with respect to the hook portion 30.

  The protrusion 22b of the present embodiment has an upper edge 22c positioned in the distal direction (front) from the closed cross-section component 21, and a lower edge 22d from the pin attachment portion 31 (second engagement portion). It is formed so as to be positioned in the distal direction (front).

<Main body 20>
The main body 20 includes a closed cross-section component 21, a protruding portion 26 on the front side of the closed cross-section component 21, and a recessed portion 27 on the rear side of the closed cross-section component 21.

  The closed cross-section component 21 has an upper plate 21a, a lower plate 21b, and side plates 21c and 21d on both left and right sides, and has a rectangular closed cross section (corresponding to the first closed cross section of the present invention). This is a housing. The upper plate 21a and the lower plate 21b are spaced apart from each other in the vertical direction, and both side ends of the upper plate 21a and the lower plate 21b are welded to the side plates 21c and 21d on both sides.

  The front and rear sides of the left and right side plates 21c and 21d (ie, the front ends 21c1 and 21d1 and the rear ends 21c2 and 21d2 in FIGS. 3 and 5) are directed forward from the lower plate 21b toward the upper plate 21a (FIG. 3). Then, it is inclined in the protruding direction A).

  The overhang portion 26 protrudes forward on the front side of the closed cross-section component portion 21 so as to continue from the upper plate 21 a to the lower plate 21 b between the pair of front side walls 22.

  Side ends 26b (see FIG. 4) on both sides of the overhang portion 26 are joined to the pair of front side walls 22 by welding. Thereby, the overhang | projection part 26 comprises a closed cross section (corresponding to the 2nd closed cross section of this invention) by being covered by the side by a pair of front side wall 22. FIG.

  The overhang portion 26 is a portion that is configured in a range extending from the upper edge 22c to the lower edge 22d of the protrusion 22b so as to cross the protrusion 22b between the pair of side walls 22 on the front side of the closed cross-section component 21. (Hereinafter, referred to as a portion between the upper and lower edges) 26c. In the present embodiment, the portion 26c between the upper and lower edges is configured in a range extending from the vicinity of the upper edge 22b of the protruding portion to the vicinity of the lower edge 22c.

  Since the overhanging portion 26 has a closed cross-sectional structure closed by the front side wall 22 from both sides and has high strength, from the viewpoint of reinforcing the hook portion 30, the portion 26c between the upper and lower edges of the overhanging portion 26 is 30 (first engaging portion) is preferably disposed closer to the hook portion 30, particularly from the upper edge 22 c to the lower edge 22 d of the protruding portion 22 b of the front side wall 22.

  Further, in the overhang portion 26 of the present embodiment, as shown in FIG. 6, the tip 26 a of the overhang portion 26 in the protruding direction A (that is, the same direction as the protruding direction A of the front side wall 22) It is located in front of the straight line L connecting the center O1 of the portion 30 and the center O2 of the pin mounting portion 31 in the protruding direction A. Here, the center O 1 of the hook portion 30 is the center of curvature of the arc-shaped back end face of the notch 32, and the center O 2 of the pin mounting portion 31 is the center of the circular pin hole 33.

  Further, the tip 26a in the protruding direction A of the overhanging portion 26 is arranged to be biased toward the upper plate 21a so as to be closer to the notch 32 of the hook portion 30 than to the pin hole 33 of the pin mounting portion 31. .

  As shown in FIG. 6, when the entire shape of the overhang portion 26 is seen, the overhang portion 26 is composed of a front extension portion 21a1, the above-described upper and lower edge portion 26c, and a tip lower side portion 26d. . The front extension portion 21a1 corresponds to a longitudinal extension portion that extends in the longitudinal direction (forward) of the closed cross-section component portion 21 in the present invention.

  The front extension portion 21a1 is a portion obtained by extending the front end portion of the upper plate 21a forward (in the direction of the protruding direction A) from the front ends of the side plates 21c and 21d (see the front end 21d1 of the side plate 21d in FIG. 6).

  The portion 26c between the upper and lower edges is continuous from the front side end portion P1 of the front extension portion 21a1 to the tip end 26a in the protruding direction A of the overhang portion 26.

  The tip lower portion 26d is a portion that continues from the tip 26a to the lower plate 21b.

  The front side end portion P1 of the front extension portion 21a1 is disposed at a position in front of the pin hole 33 of the pin mounting portion 31 in the protruding direction A.

  On the other hand, when the overhang portion 26 is viewed for each component, the overhang portion 26 includes the front plate 35 bent so as to protrude forward, the front extension portion 21a1 and the bent portion 21a3 of the upper plate 21a, the pin It consists of a cylindrical portion 25a of the support portion 25 and a front extension portion 21b1 of the lower plate 21b.

  The front extension 21a1 of the upper plate 21a is as described above. The bent portion 21a3 of the upper plate 21a is a portion where the front end portion of the upper plate 21a is bent so as to extend obliquely downward from the front end portion P1 of the front extension portion 21a1.

  The front plate 35 is bent at a position corresponding to the distal end 26a of the protruding portion 26 in the protruding direction A. The bent portion 21 a 3 of the upper plate 21 a and the upper end of the front plate 35 are welded at the position of the welding point 36. Thereby, the above-mentioned part 26c between upper and lower edges is constituted by the part above tip 26a in front board 35, and bent part 21a3 of upper board 21a.

  In the present embodiment, the angle θ between the front extension portion 21a1 and the bent portion 21a3 is more than 90 degrees so that the overhang portion 26 has a shape protruding forward from the front end portion P1 of the front extension portion 21a1 of the upper plate 21a. Is set to be a large angle (that is, an obtuse angle), it is possible to alleviate the stress concentration at the front end P1 that occurs during the dismantling operation.

  The front extension portion 21b1 of the lower plate 21b is a portion in which the front end portion of the lower plate 21b extends forward from the front ends of the side plates 21c and 21d (see the front end 21d1 in FIG. 6). The front end portion of the front extension portion 21b1 is welded to the cylindrical portion 25a. The lower end of the front plate 35 is also welded to the cylindrical portion 25a. The lower end portion 26d of the tip is constituted by the front plate 21 from the tip 26a to the end connected to the cylindrical portion 25a. The lower end portion 26 in the present embodiment is connected to the front extension portion 21b1 of the lower plate 21b via the cylindrical portion 25a.

  As shown in FIGS. 3 to 5, the recessed portion 27 is recessed toward the front of the insert boom 6 c 1 at the rear end of the insert boom 6 c 1, and is a protruding portion of the main boom 6 a connected to the rear end side of the insert boom 6 c 1. 26 (refer FIGS. 13-15) has the shape which can be accommodated.

  Side ends 27b (see FIG. 4) on both sides of the recessed portion 27 are joined to the pair of rear side walls 23 by welding.

  The recessed portion 27 is provided on the rear side of the closed cross-section component 21 and has a shape recessed forward (in the direction of the protruding direction A). The recessed portion 27 includes a rear plate 37 bent so as to protrude forward, a rear extension portion 21a2 of the upper plate 21a, a rear extension portion 21b2 of the lower plate 21b, an upper cylinder 28, and a lower cylinder 29. . The rear extension portion 21a2 of the upper plate 21a is a portion in which the rear end portion of the upper plate 21a extends rearward from the rear ends of the side plates 21c and 21d (see the rear end 21d2 of the side plate 21d in FIG. 5). The rear extension portion 21b2 is a portion in which the rear end portion of the lower plate 21ba extends rearward from the rear ends of the side plates 21c and 21d (see the rear end 21d2 in FIG. 5). The upper cylinder 28 extends in the width direction W (see FIG. 4) of the insert boom 6c2, and is welded to the rear extension portion 21a2 and the rear plate 37 of the upper plate 21a. Similar to the upper cylinder 28, the lower cylinder 29 extends in the width direction W (see FIG. 4) of the insert boom 6c2, and is welded to the rear extension portion 21b2 of the lower plate 21b and the rear plate 37, respectively.

  In the main body 20 of the present embodiment, the range having the side plates 21c and 21d on both the left and right sides constitutes a closed cross-section component 21 having a rectangular closed cross section, and protrudes forward from the front ends 21c1 and 21d1 of the side plates 21c and 21d. The portion constitutes an overhanging portion 26, and the portion protruding rearward from the rear ends 21 c 2, 21 d 2 of the side plates 21 c, 21 d constitutes a recessed portion 27.

<Back side wall 23>
As shown in FIGS. 3 to 5, the pair of rear side walls 23 are located behind the rear ends 21 c 2 and 21 d 2 of the side plates along the side plates 21 c and 21 d on both sides of the closed cross-section component 21 (see FIGS. 3 and 5). It extends in the direction B) opposite to the protruding direction A and is provided so as to protrude rearward of the main body 20.

  The rear side wall 23 is connected to the hook portion 30 and the pin attachment portion 31 (see FIGS. 13 to 15) of the main boom 6a connected to the rear end side of the insert boom 6c2.

  A pin hole 23 a is formed at a position above the rear end of the rear side wall 23. The pin holes 23a of the pair of rear side walls 23 are set to dimensions that allow both end portions of the fixing pin 24 to be fitted.

  Further, a rear projecting portion 23b projecting rearward (direction B in FIGS. 3 and 5) is formed on the lower side of the rear end of the rear side wall 23. A pin hole 23c is formed near the tip of the rearward projecting portion 23b. The pin hole 23c has substantially the same diameter as the pin hole 33 (see FIGS. 13 to 15) of the pin attachment portion 31 of the front side wall 22 of the main boom 6a connected to the rear end side of the insert boom 6c2.

  When connecting the insert boom 6c2 and the main boom 6a, the pin hole 23c on the rear side wall 23 on the insert boom 6c2 side and the pin hole 33 on the front side wall 22 on the main boom 6a side are overlapped, and these pin holes 23c and 33 are overlapped. Is inserted so that the rear side wall 23 on the insert boom 6c2 side and the front side wall 22 on the main boom 6a side are engaged.

  As shown in FIGS. 10 to 12, as the pins 50, for example, two short pieces respectively engaged with the pair of rear side walls 23 on the insert boom 6 c 2 side so that the operator can easily insert and remove the pins. Pins are used.

<Fixing pin 24>
As shown in FIGS. 3 to 5, the fixing pin 24 extends in the width direction W (see FIG. 4) of the upper plate 21 a, and both end portions thereof are fitted in the pin holes 23 a at the rear end of the rear side wall 23. doing. The fixing pin 24 has a length equal to or greater than the width of the insert boom 6c2. The fixing pin 24 is engaged with the notch 32 of the hook portion 30 in the front side wall 22 of the main boom 6a connected to the rear end side of the insert boom 6c2.

<Pin support part 25>
As shown in FIGS. 3 to 5, the pin support portion 25 is inserted into the pin holes 33 of the pair of front side walls 22 of the insert boom 6 c 2 and the pin holes 23 c of the pair of rear side walls 23 of the insert boom 6 c 1 on the distal end side thereof. A short pin 50 (see FIGS. 10 to 12) is supported from the outside in the width direction W of the insert boom 6c2. The pin support portion 25 has a cylindrical portion 25a and a pair of connecting plates 25b.

  The cylindrical portion 25 a is provided through the pair of front side walls 22. The cylindrical portion 25a is welded to the front plate 35 and the front extension portion 21b1 of the lower plate 21b between the pair of front side walls 22, respectively. Further, the cylindrical portion 25a and the pair of front side walls 22 are welded around a portion of the front side wall 22 through which the cylindrical portion 25a passes.

  The pair of connecting plates 25b is made of an elongated plate-like member. The rear side portion of the connecting plate 25b is welded to both ends of the cylindrical portion 25a so that a gap 34 is formed between the connecting plate 25b and the front side wall 22. In the gap 34, a rear protruding portion 23b (see FIGS. 7 to 9) of the rear side wall 23 of the insert boom 6c1 connected to the distal end side of the insert boom 6c2 can be inserted.

  Further, a pin hole 25b1 is formed in a portion on the front side of the connecting plate 25b. The pin hole 25b1 has substantially the same diameter as the pin hole 33 on the front side wall 22 facing the connecting plate 25b, and is aligned on the same axis as the pin hole 33.

(Configuration of main boom 6a)
The main boom 6 a shown in FIGS. 13 to 15 includes a pair of front side walls 22, a pin support portion 25, a main body 51 having an overhang portion 26, an upper swing body connecting cylinder 52, and a cylinder connecting cylinder 53. Yes.

  As described above, the main boom 6a is common to the insert boom 6c2 in that it includes the front side portion of the insert boom 6c2, that is, the pair of front side walls 22, the overhang portion 26, and the pin support portion 25. Also in the main boom 6a, as in the insert boom 6c2, the overhanging portion 26 extends from the upper edge 22c to the lower edge 22d between the pair of side walls 22 between the pair of side walls 22 on the front side of the closed cross-section component portion 54. It has the part 26c between the upper and lower edges comprised by the range. Detailed description of these parts is omitted.

  The main body 51 of the main boom 6 a has a closed cross-section component 54 and an overhang 26 on the front side of the closed cross-section component 54.

  The closed cross-section component 54 includes an upper plate 54a, a lower plate 54b, and a pair of side plates 54c and 54d. The side plates 54c and 54d are sandwiched from above and below between the upper plate 54a and the lower plate 54b. The upper and lower ends of the side plates 54c and 54d are welded to the upper plate 54a and the lower plate 54b. Both side ends of the upper plate 54a and the lower plate 54b protrude outward in the width direction from the side plates 54c and 54d. The lower plate 54b is disposed so as to be inclined upward as it goes to the rear side. The rear side ends of the upper plate 54 a and the lower plate 54 b are welded to the upper swing body connecting cylinder 52.

  The upper swing body connecting cylinder 52 is rotatably supported by a horizontal shaft attached to the upper swing body 5 of the base machine 2 shown in FIGS. Thereby, the main boom 6a is attached to the upper revolving body 5 so that it can be raised and lowered.

  The cylinder coupling cylinder 53 is slidably coupled by a pin or the like to the rod tip of the boom cylinder 10 shown in FIGS.

(Configuration of front boom 6b)
The inter boom 7 is connected around the rotation axis around the horizontal axis on the front end side of the front boom 6b shown in FIGS. Moreover, the front-end | tip part of the insert boom 6c1 is connected to the rear end side of the front boom 6b.

  The rear part of the front boom 6b has the same configuration as that of the rear part of the insert boom 6c2, that is, a pair of rear side walls 23, a recessed part 27, and a fixing pin 24. Description of these parts is omitted.

(Explanation of connection method between insert booms 6c1 and 6c2)
Next, as an example of a method for connecting a plurality of boom bodies constituting the boom 6 of the present invention, a method for connecting the insert booms 6c1 and 6c2 will be described with reference to FIGS.

  Before connecting the insert boom 6c1 and the insert boom 6c2, as shown in FIGS. 7 to 9, the rear end portion of the insert boom 6c1 faces the front end portion of the insert boom 6c2. Specifically, as shown in FIG. 2, a set of work attachments 3a excluding the main boom 6a and the insert boom 6c2 in the work attachment 3 is installed on the ground in a state of being folded in three, and the main boom 6a The insert boom 6c2 connected in advance to the tip end of the insert boom 6c2 is moved to align the tip end portion of the insert boom 6c2 with the rear end portion of the insert boom 6c1.

  Next, as shown in FIGS. 10 to 12, by driving the base machine 2, the insert boom 6 c 2 is advanced and connected to the rear end portion of the insert boom 6 c 1.

  Specifically, first, the hook portion 30 which is on the distal end side in the protruding direction A (see FIG. 3) of the front side wall 22 of the insert boom 6c2 and is closer to the upper plate 21a than the pin hole 33 of the pin mounting portion 31. The notch 32 is engaged with the fixing pin 24 arranged at the rear end portion of the insert boom 6c1.

  At this time, as shown in FIGS. 11 to 12, the rear protruding portion 23 b of the rear side wall 23 on the insert boom 6 c 1 side is inserted into the gap 34 between the connecting plate 25 b on the insert boom 6 c 2 side and the front side wall 22. Thereby, the pin hole 23c of the rear side wall 23 on the insert boom 6c1 side communicates with the pin hole 33 on the front side wall 22 on the insert boom 6c2 side and the pin hole 25b1 of the connecting plate 25b in a coaxial manner.

  At the same time, as shown in FIG. 10, the overhanging portion 26 protruding forward of the closed cross-section component 21 on the insert boom 6c2 side is located inside the recessed portion 27 recessed forward from the rear end portion of the insert boom 6c1. Get in.

  Thereafter, the operator passes a pair of short pins 50 through all of the pin holes 25b1, 23c and 33 from both sides of the insert boom 6c2, and the front side wall 22 on the insert boom 6c2 side and the rear side wall 23 on the insert boom 6c1 side. And engage. Thereby, the insert boom 6c1 and the insert boom 6c2 are engaged with the fixing pin 24 and the notch 32 on the upper side of the front side wall 22, and on the lower side, the front side wall 22 and the rear side wall 23 are connected by the pin 50. By being coupled, the rear end portion of the insert boom 6c1 and the front end portion of the insert boom 6c2 are stably fixed at two locations. Thereby, the connection between the insert booms 6c1 and 6c2 is completed.

  Moreover, the connection between other boom bodies is also possible similarly to the connection between said insert boom 6c1 and 6c2. For example, for the connection between the front boom 6b and the insert boom 6c1, it is possible to perform the connection work according to the above procedure. In this case, the insert boom 6c1 corresponds to the first boom body of the present invention, and the front boom 6b corresponds to the second boom body of the present invention. Similarly, the connection between the insert boom 6c2 and the main boom 6a can be performed according to the above procedure. In this case, the main boom 6a corresponds to the first boom body of the present invention, and the insert boom 6c2 corresponds to the second boom body of the present invention.

  On the other hand, when releasing the connection between the boom bodies, it is possible to release the connection between the boom bodies by a procedure reverse to the connection method described above.

(Features of this embodiment)
(1)
In the boom 6 of the present embodiment, when a plurality of boom bodies constituting the boom 6 are connected to each other, for example, when the insert boom 6c2 and the insert boom 6c1 on the distal end side are connected, the pair of front side walls 22 of the insert boom 6c2 is provided. The hook portion 30 and the pin attachment portion 31 that are provided are engaged with the rear end portion of the insert boom 6c1. First, the insert boom 6c2 is moved so that the notch 32 of the hook portion 30 provided at the front end of the protrusion 22b in the protrusion 22b protruding forward from the front upper portion of the front side wall 22 is inserted into the insert boom 6c1. It engages with the fixing pin 24 at the rear end. Next, the pin hole 33 of the pin mounting portion 31 located below the protruding portion 22b and rearward (near the closed cross-section component 21) is overlapped with the pin hole 23c at the rear end portion of the insert boom 6c1 to pin 50. By joining together, it becomes possible to engage the front side wall 22 of the insert boom 6c2 and the rear side wall 23 of the insert boom 6c1 on the tip side. As a result, it is possible to easily connect the insert boom 6c1 and the insert boom 6c2.

  Further, by the same procedure as this, it is possible to easily connect other boom bodies, that is, between the front boom 6b and the insert boom 6c1 and between the insert boom 6c2 and the main boom 6a. It is.

(2)
Moreover, in this embodiment, the overhang | projection part 26 is comprised in the range ranging from the upper edge 22c of the protrusion part 22b to the lower edge 22d between a pair of front side walls 22 in the front side of the closed cross-section component part 21. Since it has the edge part 26c, it is possible to concentrate and reinforce the protrusion part 22b of the front side wall 22 in which the hook part 30 which has the notch 32 was provided. Therefore, the possibility that the inner wall of the notch 32 opens and deforms can be reduced. As a result, even in the front side wall 22 having the notch 32 where stress concentration is likely to occur, the front side wall 22 is made thin by thinning a material such as a steel plate used for the front side wall 22 in a state where the rigidity and strength of the front side wall 22 are secured. Can be reduced in weight. Moreover, since the front side wall 22 can be reduced in weight and thickness, the manufacturing cost can be suppressed.

(3)
Further, in the present embodiment, the overhanging portion 26 projecting forward from the closed cross-section component portion 21 of the main body 20 has a straight line L (see FIG. 6) where the tip 26a in the protruding direction A connects the hook portion 30 and the pin mounting portion 31. Since it is located further forward in the projecting direction A, it can be disposed closer to the hook portion 30, and a portion of the front side wall 22 near the notch 32 can be reinforced by the overhanging portion 26. Become. Therefore, the possibility that the inner wall of the notch 32 opens and deforms can be reduced. In addition, both side ends of the overhang portion 26 can be connected to a range between the hook portion 30 and the pin attachment portion 31 that are likely to receive a load from the insert boom 6c1 on the front side wall 22, and the range can be reinforced. It is. Further, since the overhanging portion 26 is coupled to the front side walls 22 on both sides near the hook portion 30 and the pin mounting portion 31 and the front side walls 22 on both sides are integrated, the support rigidity of the front side wall 22 is improved. Yes. As a result, even in the front side wall 22 having the notch 32 where stress concentration is likely to occur, the front side wall 22 is made thin by thinning a material such as a steel plate used for the front side wall 22 in a state where the rigidity and strength of the front side wall 22 are secured. Can be reduced in weight. Moreover, since the front side wall 22 can be reduced in weight and thickness, the manufacturing cost can be suppressed.

  In addition, since the support rigidity of the front side wall 22 is improved by the coupling with the protruding portion 26, the distance between the hook portion 30 and the pin mounting portion 31 can be increased.

(4)
In the boom 6 of the present embodiment, the tip 26a in the protruding direction A of the overhang portion 26 is disposed at a position closer to the hook portion 30 than the pin mounting portion 31, and therefore the overhang portion 26 has a notch 32. It becomes possible to arrange the portions closer to each other, and the portion near the notch 32 in the front side wall 22 can be reinforced intensively by the overhang portion 26. Therefore, the possibility that the inner wall of the notch 32 opens and deforms can be further reduced.

(5)
In the boom 6 of this embodiment, the overhang portion 26 has a front extension portion 21a1 that extends the upper plate 21a forward, and the portion 26c between the upper and lower edges extends from the front end P1 of the front extension portion 21a1. The overhang portion 26 continues to the tip 26a in the protruding direction A, and the front side end portion P1 of the front extension portion 21a1 is disposed at a position ahead of the pin mounting portion 31 in the protruding direction A. With this configuration, not only the front end 26a in the protruding direction A of the overhang portion 26 but also the front side end portion P1 of the front extension portion 21a1 obtained by extending the upper plate 21a forward is disposed close to the hook portion 30 having the notch 32. It becomes possible. Thereby, it is possible to bring the portion 26c between the upper and lower edges between the front end P1 and the tip 26a in the protruding direction A closer to the hook portion 30. As a result, it is possible to reinforce intensively by bringing a wider part of the overhanging portion 26 closer to the portion in the vicinity of the notch 32 in the front side wall 22, and the possibility that the inner wall of the notch 32 will open and deform further. It becomes possible to reduce.

(6)
In the boom 6 of this embodiment, the insert boom 6c1 has a recessed portion 27 that is recessed forward of the insert boom 6c1 and can accommodate the overhang portion 26 at the rear end. With this configuration, the protruding portion 26 on the distal end side of the insert boom 6c2 can enter the recessed portion 27 on the rear end side of the insert boom 6c1, and the rigidity at the joint portion between the boom bodies can be improved. . Further, by absorbing the protruding amount by the projecting portion 26 by the recessed portion 27, it is possible to suppress an increase in the dimension of the boom bodies in the longitudinal direction at the joint portion between the boom bodies.

(7)
In the boom 6 of the present embodiment, the pin attachment portion 31 is disposed in the direction C from the opening 32 a in the notch 32 toward the back end 32 b with respect to the hook portion 30. With this configuration, the pin mounting portion 31 engages with the fixing pin 24 at the rear end portion of the insert boom 6c1 while the fixing pin 24 at the rear end portion of the insert boom 6c1 is engaged with the notch 32 of the hook portion 30. Thus, the pin mounting portion 31 can reliably restrict the movement of the fixing pin 24 at the rear end portion of the insert boom 6c1 from the back end of the notch 32 of the hook portion 30 toward the opening.

(Modification)
(A)
In the above embodiment, on the front side of the closed cross-section component 21 of the insert boom 6c2, a structure in which the protruding portion of the side wall provided with the first engaging portion having the notch is reinforced by the overhanging portion, that is, the front side wall 22 is provided. A hook portion 30 (first engaging portion) is provided at the front end of the protruding portion 21b, and a pin mounting portion 31 (second engaging portion) is provided below and behind the protruding portion 21b. A structure is shown in which an overhanging portion 26 is provided on the front side of the closed cross-section component 21, and the overhanging portion 26 is configured in a range extending from the upper edge 21c to the lower edge 21d of the protruding portion 21b. However, the present invention is not limited to this. On the rear side of the closed cross-section component 21, the protruding portion of the side wall provided with the first engaging portion having the notch is compensated by the overhanging portion. It may be a structure that.

  In this case, a first engagement portion having a notch is provided at the rear side end portion of the rear protrusion provided on the rear side wall 23, and the first engagement portion is provided below the rear protrusion and forward (closed cross-section component 21). 2 engaging portions are provided, and a protruding portion is further provided on the rear side of the closed cross-section component portion 21, and the protruding portion has a portion configured in a range extending from the upper edge to the lower edge of the rear protruding portion. Thus, the protruding portion of the rear side wall 23 provided with the first engaging portion having the notch can be reinforced by the overhanging portion.

(B)
In the above embodiment, one fixing pin 24 having a length equal to or longer than the width of the insert boom 6c2 is fitted in the pin hole 23a of the pair of rear side walls 23 at the rear end portion of the insert boom 6c2. Both ends are fixed by being combined, but the present invention is not limited to this, and each of the pair of short fixing pins protrudes inward from the pin holes 23a of the pair of rear side walls 23, respectively. You may make it fit in this pin hole 23a.

(C)
In the above embodiment, the dismantling machine has been described as an example of the working machine of the present invention. However, the present invention is not limited to this, and the other apparatus such as a riff mag machine having a magnet attached to the tip of the attachment. It can be widely applied to work machines.

DESCRIPTION OF SYMBOLS 1 Dismantling machine 2 Base machine 3 Work attachment 4 Lower traveling body 5 Upper turning body 6 Boom 6a Main boom 6b Front boom 6c1, 6c2 Insert boom 7 Inter boom 8 Arm 9 Working device 21 Closed cross-section component 21a Upper plate 21a1 Front extension (Longitudinal extension)
21b Lower plate 21c, 21d Side plate 21e Front plate 22 Front side wall (side wall)
22a front end 23 rear side wall 24 fixing pin 25 pin support part 26 overhang part 26a front end 26b side end 26c upper and lower edge part 26d front end lower part 27 recessed part 30 hook part (first engaging part)
31 Pin mounting part (second engaging part)
32 Notch 32a Opening 32b Back end 33 Pin hole

Claims (1)

A first boom body;
A second boom body disposed at the longitudinal end of the first boom body,
The first boom body includes an upper plate, a lower plate, and left and right side plates, and the upper plate, the lower plate, and the left and right side plates constitute a closed cross section constituting the first closed cross section, A pair of side walls provided so as to protrude in the longitudinal direction of the closed cross-section component along the side plates on both sides of the closed cross-section component, and projecting in the longitudinal direction of the closed cross-section component, and sided by the pair of side walls An overhanging portion covering the side and forming a second closed cross-section,
The side wall is provided at a projecting portion projecting in the longitudinal direction of the closed cross-section component portion and an end portion in the projecting direction of the projecting portion, and is detachably engaged with an end portion in the longitudinal direction of the second boom body. A first engaging portion capable of being detachably engaged with a longitudinal end portion of the second boom body, which is disposed at a position lower than the projecting portion and closer to the closed cross-section component. An engaging portion,
The first engagement portion has a notch that can be engaged with an end portion in the longitudinal direction of the second boom body,
The overhanging portion has a portion configured in a range extending from the upper edge to the lower edge of the protruding portion, and has a front end between the first engaging portion and the second engaging portion. With a protruding shape ,
The boom of the working machine characterized by this.

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