JP4885493B2 - Telescopic boom - Google Patents

Description

  The present invention relates to a telescopic boom in which a line-shaped member including an oil feeding hose, a signal transmission line, and the like is disposed along a boom body that is configured to be telescopically movable.

  A telescopic boom provided in an aerial work vehicle, a crane truck, etc. includes a boom main body in which a plurality of boom members are nested, and a boom telescopic means for moving the boom main body relative to each other by relatively moving the plurality of boom members. (For example, an expansion cylinder). In such a telescopic boom, pressure oil is supplied to an actuator (for example, a hydraulic motor that swings a work platform of an aerial work vehicle provided at the distal end of the boom body) disposed at the distal end of the telescopic boom. A line-shaped member consisting of an oil feeding hose and a signal transmission line connecting between the base end side and the tip end side of the boom is provided, and this line-shaped member is also expanded and contracted as the boom body expands and contracts. It is the composition which becomes.

It is necessary to move the line-shaped member smoothly according to the expansion and contraction movement of the boom body and orderly without entanglement with other devices and members arranged inside the boom body (the entire line-shaped member expands and contracts). As a conventional technique that satisfies the requirements, one or more belt-shaped protective guide members are provided inside or outside the boom body of the telescopic boom, and a line-shaped member is accommodated in these (these) protective guide members. (For example, refer to the following patent document). The protective guide member is bent and arranged so as to have a convex shape on the proximal end side or the distal end side of the boom body, and both ends thereof are fixed to two different boom members constituting the boom body. The line-shaped member accommodated in the protective guide member is fixed at both ends of the protective guide member. When the boom body expands and contracts, the protection guide member is deformed (moved) so as to change the length from the bent portion to both fixed ends, and the line-shaped member also moves according to the movement of the protection guide member. Since the line-shaped member is accommodated in the protective guide member, the line-shaped member is not entangled with other devices or members disposed in the boom body, or is not damaged by the other members or devices.
JP 2004-189356 A

  However, in the above conventional configuration, various problems have occurred because the line-shaped member is fixed at both ends of the protective guide member. For example, the line-shaped member housed in the protective guide member is mixed with different types such as an oil feeding hose and a signal transmission line. However, the line-shaped members of different types usually have different materials and sizes (diameters). ) Is different, when a protective guide member is deformed (moved), a certain line-shaped member receives a tensile force, while another line-shaped member receives a compressive force. The line-shaped member may be bent inside the protective guide member and entangled with other line-shaped members. Further, when the line-shaped member is entangled or bent by receiving a compressive force, a force for twisting the protective guide member is generated, and smooth deformation of the protective guide member may be hindered.

  The present invention has been made in view of such a problem, and provides a telescopic boom having a configuration in which the line-shaped members are not entangled in the protective guide member and the protective guide member is not twisted. The purpose is to do.

The telescopic boom according to the present invention includes a boom body (for example, a distal end boom 32a in the embodiment) and a distal end boom (for example, the distal boom 32b in the embodiment) configured in a telescopic manner. The lower boom body 32) in the embodiment, the boom extending / contracting means (for example, the expansion cylinder 33 in the embodiment) for moving the boom body in an axial direction by relatively moving the proximal boom and the distal boom in the axial direction, and one end portion (For example, the upper end portion 37a in the embodiment) is fixed to the outer surface of the base end side boom and extends to the base end side of the boom main body, and then bent so as to be convex toward the base end side of the boom main body. enters the inside of the proximal boom, it is then fixed and the other end portion extending toward the distal end side of the boom assembly (e.g., a lower end portion 37b in the embodiment) inside the tip-side boom A protective guide member for relative movement in the axial direction other end to the distal end portion is deformed as a whole in accordance with the relative movement of the proximal boom and distal boom, the external proximal boom boom After extending from the proximal end side toward the distal end side, it reverses in a U shape toward the proximal end side of the boom body, enters the protective guide member from the one end portion of the protective guide member, and follows the protective guide member And a line-shaped member extending from the other end of the protective guide member and extending in the distal-end boom, and extending from the base end side of the boom body to the distal end side of the line-shaped member. The portion is fixed to the proximal boom, and the portion located at the other end of the protective guide member in the line-shaped member is fixed to the other end of the protective guide member or the other end of the protective guide member That protrudes from the inside of the boom on the tip side It is fixed relative to the distal end side boom, the outer surface of the proximal boom axially where it emerges from the one end portion of the protective guide member of the line-shaped member to the outside of the protective guide member relative to the protective guide member The support means (for example, the support member 54 in the embodiment) is provided so as to be supported so as to be movable relative to each other .

  In the telescopic boom, a proximal end boom is preferably provided with a hole or notch extending in the axial direction, and the protective guide member extends from the one end to the other end through the hole or notch. . When such a configuration is adopted, a hollow reinforcing member extending in the axial direction of the proximal boom is provided on the outer surface of the proximal boom so as to follow the inner edge of the hole or notch. It is preferable that a portion of the line-shaped member extending from the base end side to the tip end side of the boom body passes through the inside of the reinforcing member.

In the telescopic boom according to the present invention, when the boom main body expands and contracts, the portion of the line-shaped member that is housed inside the protective guide member moves according to the deformation (movement) of the protective guide member (as the entire line-shaped member). The portion of the line-shaped member positioned at one end of the protective guide member (the end on the side fixed to the distal boom) is the end of the protective guide member (the distal boom). (Or the portion of the protective guide member that protrudes from the one end of the protective guide member to the inside of the distal boom) is fixed to the distal boom. The portion located at the other end of the protection guide member (the end on the side fixed to the base end boom) is the end of the protection guide member (the end on the side fixed to the base end boom). Since it is not fixed to the line member Mamoru can be relatively moved in the direction of extension of itself to the guide member (the movement amount, after extending toward the distal end side exterior of the proximal boom from the base end of the boom, boom Is absorbed by deformation of the U-shaped portion that reverses in a U-shape toward the base end side of the Therefore, in the telescopic boom according to the present invention, the portion of the line-shaped member that is accommodated in the protection guide member is accommodated in the protection guide member, which is likely to occur when both ends of the protection guide member are fixed. In addition, since the materials and sizes (diameters) of the plurality of line-shaped members are different, a phenomenon that a certain line-shaped member receives a tensile force but other line-shaped members receive a compressive force does not occur. There is no possibility that the line-shaped members are entangled in the protective guide member or the protective guide member is twisted by the line-shaped member bent by receiving the compressive force. In addition, the assembly is much easier than when the line-shaped member is fixed to both ends of the protective guide member, and the cost required for the assembly of the telescopic boom can be reduced.

  Further, if the proximal boom is provided with a hole or notch extending in the axial direction and the protective guide member extends from the one end to the other end through the hole or notch, the protective guide is provided. Since the entire member can be accommodated in the boom body, the total length of the telescopic boom itself can be shortened. Further, when such a configuration is adopted, a hollow reinforcing member extending in the axial direction of the proximal boom is provided on the outer surface of the proximal boom so as to follow the inner edge of the hole or notch. If the portion extending from the proximal end side of the boom body toward the distal end side passes through the inside of this reinforcing member, while suppressing the rigidity reduction of the proximal boom by forming a hole or notch, It becomes possible to sufficiently protect the line-shaped member that has come out of the protective guide member.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG.2 and FIG.3 has shown the aerial work vehicle 1 provided with the telescopic boom which concerns on one Embodiment of this invention. This aerial work vehicle 1 is provided with traveling wheels 11, 11,... That can be operated from the driving cabin 12 by a truck-type traveling body 10, a swivel strut 20 provided on the traveling body 10, A boom 30 having a base end supported on the upper part of the swivel strut 20 via a foot pin 21 and a work board 60 for boarding an operator attached to the distal end of the boom 30 are configured.

  The swivel strut 20 is mounted on the traveling body 10 so as to be rotatable 360 degrees around the vertical axis. A swing motor (hydraulic motor) 23 is provided inside the traveling body 10, and by rotating the swing motor 23, the swing strut 20 can be swung around a vertical axis via a gear (not shown). it can.

  The boom 30 includes a lower boom 31 which is an embodiment of the telescopic boom according to the present invention, and an upper boom 41 connected to the lower boom. The lower boom 31 includes a lower boom body 32 in which a proximal boom 32a and a distal boom 32b are nested, and the lower boom 31 is provided inside the lower boom body 32 so that the proximal boom 32a and the distal boom 32b are relatively moved in the axial direction. And a telescopic cylinder (hydraulic cylinder) 33 for expanding and contracting the lower boom body 32. Further, a hoisting cylinder (hydraulic cylinder) 24 is straddled between the proximal boom 32a and the swivel strut 20, and the lower boom 31 can be moved up and down by operating the hoisting cylinder 24 to extend and contract. It is.

  The upper boom 41 is composed of an upper rod 41a and a lower rod 41b arranged in parallel. The proximal ends of both the rods 41a and 41b are pivotally supported by a first metal fitting 34 provided at the distal end of the distal boom 32b. In addition, a second metal fitting 42 is attached to the tip side end portions of both rods 41a and 41b. Both rods 41a and 41b constitute a parallel link mechanism together with the first metal fitting 34 and the second metal fitting 42, so that the parallel posture is always maintained. A bending / extending cylinder 43 is straddled between the lower rod 41b and the tip boom 32b, and the entire upper boom 41 can be bent and extended with respect to the lower boom 31 by operating the bending cylinder 43 to extend and contract.

  The lower end of the vertical post 44 is supported by the second metal fitting 42 attached to the tip of the upper boom 41 (tips of both rods 41a and 41b). The vertical post 44 is always held in a vertical posture by a leveling device (not shown).

  The work table 60 has a box shape, and an arm member 61 is provided on a side surface of the work table 60 so as to protrude from the work table 60. The arm member 61 is rotatably attached to the upper end portion of the vertical post 44. By rotating a swing motor (electric motor) 62 provided therein, the entire work table 60 is rotated around the vertical post 44. Can be swung (horizontal turning). Here, since the vertical post 44 is always kept in the vertical posture as described above, as a result, the floor surface of the work table 60 is always kept horizontal regardless of the posture of the boom 30.

  An operation unit 63 projecting outward is provided on the side wall of the work table 60, and an operator who has boarded the work table 60 moves the boom operation lever 63 a and the work table operation lever 63 b provided in the operation unit 63. By operating, it is possible to perform operations such as turning, undulating, expanding and contracting, bending and stretching of the boom 30 and swinging (of the arm member 61) of the work table 60.

  As shown in FIG. 4, the swing motor 23 is connected to the bending cylinder 43 via the swing motor operation valve 23v, the lifting cylinder 24 via the lifting cylinder operation valve 24v, and the expansion cylinder 33 via the expansion cylinder operation valve 33v. The pressure oil discharged from the hydraulic pump P provided in the traveling body 10 is supplied to the swing motor 62 via the bending cylinder operation valve 43v and the swing motor operation valve 62v. The swing motor operation valve 23v, the hoisting cylinder operation valve 24v, the telescopic cylinder operation valve 33v and the bending cylinder operation valve 43v are all electromagnetic proportional directional flow control valves, and the controller 80 provided in the traveling body 10 includes an operation unit. The spools of the swing motor operation valve 23v, the hoisting cylinder operation valve 24v, the telescopic cylinder operation valve 33v, and the bending / extension cylinder operation valve 43v are driven based on the operation signal output by operating the boom operation lever 63a provided in 63. As a result, the swing motor 23, the hoisting cylinder 24, the telescopic cylinder 33, and the bending cylinder 43 operate at directions and speeds corresponding to the driving states of the respective spools (not shown) of the valves 23v, 24v, 33v, 43v. . On the other hand, the swing motor operation valve 62v is a manually operated directional flow control valve, and its spool is directly driven by the operation of a worktable operation lever 63b provided in the operation unit 63. The swing motor 62 is a swing motor. The operation valve 62v operates in a direction and speed corresponding to a driving state of a spool (not shown).

  With such a configuration, an operator who has boarded the work table 60 operates the boom operation lever 63a to rotate, undulate, extend and contract and extend the boom 30, or operate the work table operation lever 63b to operate the work table 60. , The work table 60 on which it is boarded can be moved to a desired position. Outrigger jacks 13 are provided at the front, rear, left and right four places of the traveling body 10. If the outrigger jacks 13 are protruded downward (extension operation) and brought into a grounded state before work, the traveling body 10 is stably provided. Therefore, it is possible to work safely against a large falling moment acting on the traveling body 10.

  As described above, the lower boom 31 includes the telescopic cylinder 33 in the lower boom body 32, and also includes the line-shaped member 36 and the protective guide member 37 (see FIGS. 1 and 5 to 7). As shown in FIGS. 6 and 7, the telescopic cylinder 33 has a cylinder tube 33a attached to the proximal end side of the proximal boom 32a, and a piston rod 33b attached to the distal end side of the distal boom 32b. Therefore, when the telescopic cylinder 33 is expanded and contracted, the distal end boom 32b moves in the axial direction with respect to the proximal end boom 32a, and the entire lower boom body 32 expands and contracts. A section member 38 having a U-shaped section extending in the axial direction and vertically dividing the inner space of the tip boom 32b is provided in the tip boom 32b. The telescopic cylinder 33 is partitioned by the partition member 38. (See FIG. 6 and FIG. 8). Further, a guide rail 39 having a U-shaped cross section extending in the axial direction of the distal end boom 32b is provided on the upper surface side of the partition member 38 (see FIGS. 6 and 8).

  The line-shaped member 36 is provided between two oil feeding hoses 36 a that supply pressure oil to a hydraulic actuator such as a swing motor 62 disposed at the distal end of the boom 30, and between the proximal end side and the distal end side of the boom 30. 4, each of which extends from the traveling body 10 and passes through the lower boom body 32 and the upper boom 41 to reach the work table 60 (see FIG. 1 and FIG. 1). (See FIG. 6).

  As shown in FIG. 9, a hole (rectangular elongated hole) 40 extending in the axial direction of the proximal boom 32a is formed in the upper portion of the proximal boom 32a (see also FIGS. 6 and 7). On the upper surface of the boom 32a, hollow reinforcing members 52a and 52b extending in the axial direction of the proximal boom 32a are provided along the left and right inner edges of the hole 40. Further, a protective guide member fixing base 51 formed in a trapezoidal shape is attached to a position on the upper surface of the base end boom 32a in front of the front edge of the hole 40 (the front end side of the base end boom 32a).

  As shown in FIG. 10, the protective guide member 37 has a configuration in which a large number of link members L having a hollow rectangular cross-sectional shape are continuously coupled by coupling pins C, and is configured as a belt that can be bent as a whole. Has been. One end portion (upper end portion 37a) of the protection guide member 37 is fixed on the protection guide member fixing base 51 attached to the outer surface (upper surface) of the base end boom 32a by using an upper end portion fixing tool 53, The member 37 extends from here to the base end side of the lower boom body 32. And it bends so that it may become convex shape toward the base end side of the lower boom main body 32 (At this time, it passes the hole 40 formed in the upper surface of the base end boom 32a. Moreover, the part bent in the convex shape is a bending part. 37c (shown as 37c in the drawing) and then extends toward the distal end side of the lower boom body 32, and the other end portion (lower end portion 37b) is located inside the distal end boom 32 (specifically, the guide rail 39). It is fixed to the proximal end (see FIGS. 6 and 7).

  Further, as shown in FIG. 1, the line-shaped member 36 is slidable in the extending direction at a position in front of the upper end fixture 53 (the distal end side of the proximal boom 32a) in the protection guide member fixing base 51. A support member 54 is provided for support. As shown in detail in FIG. 8, the support member 54 is attached by two screws 54d extending in the vertical direction so that the plate-like lower step member 54a, middle step member 54b and upper step member 54c are parallel to each other. The space between the lower step member 54a and the middle step member 54b and the space between the middle step member 54b and the upper step member 54c are respectively connected to the outside of the protection guide member 37 from the upper end portion 37a of the protection guide member 37 of the line member 36. The protruding portion is supported so as to be movable in the direction in which it extends (same as the direction in which the lower boom body 32 extends here).

  The two oil supply hoses 36a extending from the traveling body 10 are fixed to the right side surface of the base end boom 32a by the fixture 55 (see FIGS. 5 and 1), and then attached to the right side surface of the base end boom 32a. The oil feeding hose inlet 35ai drilled in the right bracket 35a enters the right reinforcing member 52a (the side of the right reinforcing member 52a is also provided with an oil feeding hose inlet not shown), and the front of the lower boom body 32 After extending to the (front end side), it reverses in a U shape (toward the base end side of the lower boom body 32) when it exits from the front end portion (the end portion on the front end side of the lower boom body 32) of the right reinforcing member 52a. The protective guide member 37 enters the protective guide member 37 from the upper end portion 37 a of the protective guide member 37 via the support member 54. Further, the four signal transmission lines 36b extending from the traveling body 10 are fixed to the left side surface of the base end boom 32a by a fixing tool 56 (see FIG. 5), and then the left side attached to the left side surface of the base end boom 32a. The signal transmission line inlet 35bi (see FIG. 9) drilled in the bracket 35b enters the left reinforcing member 52b (a signal transmission line inlet (not shown) is also provided on the side of the left reinforcing member 52b), and the lower boom. After extending to the front of the main body 32, when it comes out from the front end portion of the left reinforcing member 52 b, it is reversed in a U shape (toward the base end side of the lower boom main body 32), The protective guide member 37 is entered from the upper end portion 37 a of 37. The two oil feeding hoses 36 a and the four signal transmission lines 36 b that enter the protective guiding member 37 from the upper end portion 37 a of the protective guiding member 37 are respectively in the internal spaces of the link members L constituting the protective guiding member 37. After extending from the lower end portion 37b of the protection guide member 37 to the outside of the protection guide member 37, that is, into the front end boom 32b, the guide member 39 is guided to extend to the front end side of the front end boom 32b. Here, as shown in FIG. 10, clamp members 57 and 58 are provided on the guide rail 39, and line members 36 (two oil feeding hoses 36 a and four oil supply hoses 36 a) extending along the guide rail 39. The signal transmission line 36b) is fixed on the guide rail 39 (that is, with respect to the distal end boom 32b) by these clamp members 57 and 58 (see also FIGS. 6 and 7).

  As shown in FIGS. 2 and 3, a cover member 59 is provided on the upper surface of the proximal boom 32a (see also FIGS. 6 and 7). The cover member 59 is for protecting the protection guide member 37 and the line-shaped member 36 exposed on the upper surface side of the proximal boom 32a, and a plurality of nut members provided on the upper surfaces of the left and right reinforcing members 52a and 52b. A plurality of bolts B (see FIG. 2) screwed with N (see FIGS. 1 and 5) are detachably coupled to the left and right reinforcing members 52a and 52b.

  In the lower boom 31 having such a configuration, when the telescopic cylinder 33 is extended from a state in which the lower boom body 32 is not fully extended (for example, the fully contracted state shown in FIG. 6), the distal boom 32b is moved forward (the distal end of the proximal boom 32a). The protection guide member 37 is deformed (moved) so that the lower end portion 37b is moved forward. On the other hand, when the telescopic cylinder 33 is contracted from a state in which the lower boom body 32 is not fully contracted (for example, the fully extended state shown in FIG. 7), the distal end boom 32b moves rearward (the proximal end side of the proximal boom 32a). The protective guide member 27 is deformed to move the lower end portion 37b rearward. When the protective guide member 37 is deformed to move the lower end portion 37 forward or backward as described above, the bent portion 37c of the protective guide member 37 is a hole provided in the upper portion of the proximal boom 32a. The inside of 40 will move to the front-back direction of the base end boom 32a.

  When the lower boom body 32 expands and contracts, the portion of the line member 36 accommodated inside the protective guide member 37 moves according to the deformation of the protective guide member 37 (the entire line member 36 expands and contracts). However, the portion of the line-shaped member 36 that protrudes from the lower end portion 37b of the protective guide member 37 to the inside of the tip boom 32b is fixed to the tip boom 32b (the clamp member 57 is fixed onto the guide rail 39). However, since the portion located at the upper end portion 37 a of the protection guide member 37 is not fixed to the upper end portion 37 a of the protection guide member 37, the line-shaped member 36 extends in the direction of its own extension with respect to the protection guide member 37. (The amount of movement is absorbed by deformation of the U-shaped portion of the line-shaped member 36).

  Therefore, in the lower boom 31, the line-shaped member 36 is accommodated in the protective guide member 37 that tends to occur when the portions accommodated in the protective guide member 37 are fixed at both ends of the protective guide member 37. Since a plurality of line-shaped members 36 (two oil feeding hoses 36a and four signal transmission lines 36b) are different in material and size (diameter), a certain line-shaped member 36 receives a tensile force. However, the other line-shaped member 36 is not subjected to a phenomenon such as receiving a compressive force, and the line-shaped member 36 is entangled in the protective guide member 37 or is bent by receiving the compressive force. The protective guide member 37 is not twisted by 36. Further, the assembly is much easier than when the line-shaped member 36 is fixed to both ends of the protective guide member 37, and the cost required for the assembly of the lower boom 31 can be reduced.

  In the lower boom 32, a hole 40 extending in the axial direction is provided in the proximal boom 32 a, and the protective guide member 37 extends from the upper end portion 37 a to the lower end portion 37 b through the hole 40. For this reason, the entire protection guide member 37 can be accommodated in the lower boom body 32, and the entire length of the lower boom 32 itself can be shortened. Further, hollow reinforcing members 52a and 52b extending in the axial direction of the base end boom 32a along the inner edge of the hole 40 are provided on the upper surface of the base end boom 32a, and the lower boom body 32 of the line member 36 is provided. Since the portion extending from the proximal end side toward the distal end side passes through the inside of the reinforcing members 52a and 52b, the rigidity of the proximal end boom 32a due to the formation of the hole 40 is suppressed, and the protective guide member 37 is protected. The line-shaped member 36 that has come out to the outside can be sufficiently protected.

  The preferred embodiments of the present invention have been described so far, but the scope of the present invention is not limited to those shown in the above-described embodiments. For example, in the above-described embodiment, the portion of the line-shaped member 36 that protrudes from the lower end portion 37b of the protection guide member 37 to the inside of the tip boom 32b is fixed to the tip boom 32b. A clamp member may be provided at the lower end portion 37 b of the member 37, and a portion of the line-shaped member 36 positioned at the lower end portion 37 b of the protection guide member 37 may be fixed to the lower end portion 37 b of the protection guide member 37. .

  Further, in the above-described embodiment, the protective guide member 37 extends from the upper end portion 37a to the proximal end side of the lower boom body 32, then bends into a convex shape through the hole 40, and then enters the distal end boom 32b. However, the base end boom 32a is not provided with the hole 40, and the protective guide member 37 extends from the upper end portion 37a to the base end side of the base end boom 32a. It is good also as a structure which bends so that it may become convex shape through the outer side of the rear edge of the end boom 32a, and then enters into the front end boom 32b and extends toward the front end side of the lower boom body 32. In the above-described embodiment, the protective guide member 37 has a configuration extending from the upper end portion 37a to the lower end portion 37b through the hole 40 provided in the proximal end boom 32a. The notch which has an open part in the rear edge (base edge side edge) of the end boom 32a may be sufficient.

  Further, in the above-described embodiment, of the two end portions of the protection guide member, the end portion on the side attached to the outer surface of the base end side boom (base end boom 32a) is attached to the upper surface of the base end side boom. However, it can also be attached to the bottom and side surfaces of the proximal boom. In the above-described embodiment, the boom main body (lower boom main body 32) that is expanded and contracted by the expansion / contraction cylinder 33 that is a boom expansion / contraction means is configured by a two-stage boom member including a proximal boom 32a and a distal boom 32b. However, the boom main body of the telescopic cylinder to which the present invention is applied does not necessarily have to be composed of two-stage boom members, and has at least two-stage boom members of a proximal end boom and a distal end boom. Any number of boom configurations may be used.

  Moreover, although the aerial work vehicle equipped with the telescopic boom according to the present invention is configured to travel by tire wheels in the above-described embodiment, it does not necessarily have to travel by tire wheels. For example, the vehicle may travel. Alternatively, it may be an aerial work platform for running on a track with wheels for running on a track, or an aerial work vehicle for both roads and roads equipped with both tire wheels and wheels for running on a track. . Further, in the above-described embodiment, the case where the telescopic boom according to the present invention is applied to an aerial work vehicle is shown, but this is an example, and it can also be applied to other boom work vehicles, for example, crane vehicles. It is.

It is a perspective view of a lower boom of an aerial work vehicle, which is a telescopic boom according to an embodiment of the present invention. It is a back perspective view of the aerial work vehicle. It is a side view of the aerial work vehicle, (A) shows a state where the lower boom in a horizontal posture is extended, and (B) shows a state where the lower boom and the upper boom are positioned so as to extend in the vertical direction. ing. It is a block diagram which shows the operation system of the boom in the said aerial work vehicle, and a worktable. It is a partial top view of the said lower boom. It is sectional drawing of the lower boom seen from arrow VI-VI in FIG. 5, and is a figure when a lower boom main body is made into a fully contracted state. It is a fragmentary sectional view of a lower boom when a lower boom body is made into a fully extended state. It is sectional drawing of the lower boom seen from arrow VIII-VIII in FIG. It is a partial exploded perspective view of the lower boom which shows the attachment condition of the reinforcement member with respect to a base end boom. It is a perspective view of the protection guide member connected with the guide rail.

Explanation of symbols

31 Lower boom (telescopic boom)
32 Lower boom body (Boom body)
32a Base end boom (base end side boom)
32b Tip boom (tip boom)
33 Telescopic cylinder (Boom telescopic means)
36 Line-shaped member 36a Oil supply hose 36b Signal transmission line 37 Protection guide member 37a Upper end portion of protection guide member (one end portion of protection guide member)
37b Lower end of the protection guide member (the other end of the protection guide member)
40 hole 52a, 52b reinforcement member

Claims (3)

A boom body including a proximal boom and a distal boom configured in a telescopic manner; and
Boom extending and retracting means for expanding and contracting the boom body by relatively moving the proximal end boom and the distal end boom in the axial direction;
After having one end extending proximally of the boom body is fixed to the outer surface of the proximal-side boom, the proximal-side boom is bent so as to project toward the base end side of the boom of enters the inside, is then fixed the extending toward the distal end side of the boom assembly second end portion to an inside of the distal-side boom deflection as a whole in accordance with the relative movement of the proximal-side boom and the distal-side boom A protective guide member that deforms and the other end portion moves relative to the tip portion in the axial direction ;
The outside of the base end side boom extends from the base end side of the boom main body toward the front end side, and then reverses in a U shape toward the base end side of the boom main body, and the one end portion of the protection guide member A line-shaped member that extends into the protective guide member and extends along the protective guide member, and extends from the other end portion of the protective guide member and then extends through the distal end boom.
A portion of the line-shaped member extending from the proximal end side to the distal end side of the boom body is fixed to the proximal-end boom, and the other end portion of the protective guide member in the line-shaped member is fixed to the proximal end-side boom. A portion located is fixed to the other end portion of the protective guide member, or a portion that protrudes from the other end portion of the protective guide member into the distal end boom is fixed to the distal end boom .
On the outer surface of the base end side boom, a portion of the linear member that protrudes from the one end portion of the protection guide member to the outside of the protection guide member along the axial direction with respect to the protection guide member. And a telescopic boom, characterized in that it is provided with a support means for supporting it in a relatively movable manner .   A hole or notch extending in the axial direction is provided in the proximal boom, and the protective guide member extends from the one end to the other end through the hole or notch. The telescopic boom according to Item 1.   A hollow reinforcing member extending in the axial direction of the base end side boom is provided on the outer surface of the base end side boom so as to follow the inner edge of the hole or notch, and the base end of the boom body in the line member The telescopic boom according to claim 2, wherein a portion extending from the side toward the tip side passes through the inside of the reinforcing member.

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