Undercutter Device

Abstract

To easily change an angle of an under cutter part.SOLUTION: An under cutter device includes a coupler part 11 that is connected to the tip of a working arm of a backhoe, a cutter suspension support part 13 that is rotatably connected to the coupler part 11 and has leg parts 13b, 13b extending downward and an under cutter part 14 that is connected to a leg side connecting part 13e of the leg parts 13b, 13b of the cutter suspension support part 13 via a cutter side connecting part 14b, and excavates the track bed by moving multiple excavation claws 14a5. The leg side connecting part 13e and the cutter side connecting part 14b are rotatably connected by a rotation shaft 13e1 extending parallel to the upper surface of the under cutter part 14, and are rotatably connected to the cutter suspension support part 13 and the under cutter part 14. There is an extension mechanism 15 that extends and retracts, so that the under cutter part 14 rotates about the rotation shaft 13e1 to change the angle.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an undercutter device that is replaceably attached to an attachment mounting portion at the tip of a working arm of a backhoe and excavates a roadbed by moving multiple excavation blades attached to a chain belt. [Background technology]

[0002] Undercutter devices have been put into practical use in the past, in which multiple digging claws are attached to a chain belt and moved by rotating the chain belt, thereby digging the construction base surface or the track bed under sleepers (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5869487 [Patent Document 2] Patent No. 6817640 [Patent Document 3] Utility Model Registration No. 3225463 Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, in railway tracks, for example, as shown in Figure 9, a 3% water gradient (also called a drainage gradient) is provided between the roadbed 2 made of concrete or the like and the trackbed 3 made of crushed stone (ballast) that supports sleepers M on which rails R are installed, and rainwater that falls on the tracks during rainfall is designed to be drained by flowing into trackside gutters 2a installed on the roadbed 2 beside the tracks using the 3% water gradient between the roadbed 2 and the trackbed 3.

[0005] However, there was no dedicated machine to create a water gradient between the roadbed 2 and the trackbed 3, and workers had to create the water gradient using shovels, bulldozers, excavators, etc., which meant that the work of setting up the water gradient took a very long time and required efficiency in the work of forming the water gradient.

[0006] Therefore, the present invention has been made with an eye on such problems, and aims to provide an undercutter device that can easily change the angle of the undercutter section, such as by easily creating a water gradient between the roadbed and the trackbed. [Means for solving the problem]

[0007] In order to solve the above problems, the undercutter device of the present invention comprises a coupler section connected to an attachment mounting section at the tip of the operating arm of a backhoe, a cutter hanging support section rotatably connected to the coupler section and having legs extending downward, and an undercutter section connected to the leg side connecting section of the legs via a cutter side connecting section and excavating the track bed by moving multiple excavation claws, the leg side connecting section and the cutter side connecting section are rotatably connected by a rotation shaft extending parallel to the upper side of the undercutter section, and an extension mechanism section having both ends rotatably connected to the cutter hanging support section and the undercutter section, respectively, and is configured so that by extending and contracting the extension mechanism section, the undercutter section rotates relative to the cutter hanging support section via the rotation shaft to change the angle of the undercutter section. The pivot shaft is eccentrically disposed toward the tip of the undercutter from the center of the leg in the longitudinal direction of the undercutter, and an upward inclination stopper is provided on the end surface of the leg at the tip of the undercutter, which contacts the end surface of the cutter-side connecting part when the tip of the undercutter rises with respect to the horizontal plane of the coupler part and inclines by a predetermined angle or more, and the predetermined angle is the angle of the water gradient provided between the roadbed and the track bed. It is characterized by: Further, in the undercutter device according to the present invention, The backhoe excavator is provided with a coupler section connected to an attachment mounting section at the tip of the operating arm of the backhoe, a cutter suspension support section rotatably connected to the coupler section and having legs extending downward, and an undercutter section connected to the leg side connector of the legs via a cutter side connector and excavating the track bed by moving a plurality of excavation claws, the leg side connector and the cutter side connector are rotatably connected by a rotation shaft extending parallel to the upper side of the undercutter section, and an extension mechanism section having both ends rotatably connected to the cutter suspension support section and the undercutter section, respectively, and the undercutter excavator is provided with a coupler section connected to an attachment mounting section at the tip of the operating arm of the backhoe, a cutter suspension support section rotatably connected to the coupler section and having legs extending downward, the undercutter excavator is provided with a coupler section connected to the coupler section rotatably The section is configured to rotate relative to the cutter hanging support section via the rotation shaft to change the angle of the undercutter section, and the rotation shaft is provided eccentrically toward the tip side of the undercutter section relative to the center of the leg section in the longitudinal direction of the undercutter section, and a downward inclination stopper that the lower end surface of the leg section abuts is provided on the telescopic mechanism section side relative to the connection point with the rotation shaft in the cutter side connection section when the undercutter section is inclined downward at the tip by more than a predetermined angle due to the tip side of the undercutter section lowering with respect to the horizontal plane of the coupler section, and the predetermined angle is the angle of the water gradient provided between the roadbed and the track bed. It is also characterized by: In addition, the undercutter device of the present invention is also characterized in that the telescopic mechanism is composed of a nut body having a female thread portion, one end of which is rotatably connected to the underside of the cutter hanging support part, and a threaded rod having a male thread portion, one end of which is rotatably connected to the upper surface of the undercutter part, and the other end of which screws into the female thread portion of the nut body. [Effects of the Invention]

[0008] In the undercutter device of the present invention, an extension mechanism is provided between the cutter hanging support part and the undercutter part, and by extending or contracting the extension mechanism, the undercutter part rotates relative to the cutter hanging support part via the pivot axis, thereby allowing the angle (elevation angle) of the undercutter part to be changed. Therefore, by using the telescopic mechanism to change the angle of the undercutter part relative to the cutter hanging support part, it is possible to change the angle of the undercutter part, for example, to easily create a water gradient between the roadbed and the trackbed, thereby improving work efficiency. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a side view of an entire undercutter device according to an embodiment of the present invention. [Figure 2] 1 is an enlarged side view showing essential parts such as a coupler part and a cutter suspension support part in an undercutter device according to an embodiment of the present invention. FIG. [Figure 3] 3A and 3B are enlarged side views of essential parts showing the mounting positions of an upwardly inclined stopper and a downwardly inclined stopper in an undercutter device according to an embodiment of the present invention. [Figure 4] 1 is an enlarged rear view showing essential parts such as a coupler part and a cutter suspension support part in an undercutter device according to an embodiment of the present invention. FIG. [Figure 5] 1 is a side view showing an undercutter device according to an embodiment of the present invention, with the undercutter section set to a water gradient angle of +3%. FIG. [Figure 6] (a) to (c) are enlarged side views, enlarged front views, and enlarged rear views of key parts, respectively, showing the abutment state of the upward inclined stopper and the downward inclined stopper in an undercutter device of an embodiment of the present invention when the undercutter section is set to a water gradient angle of +3%. [Figure 7] FIG. 1 is a side view showing an undercutter device according to an embodiment of the present invention, with the undercutter section set to a water gradient of −3% in a clockwise direction. [Figure 8] (a) to (c) are enlarged side views, enlarged front views, and enlarged rear views of key parts, respectively, showing the abutment state of the upward inclined stopper and the downward inclined stopper in an undercutter device according to an embodiment of the present invention when the undercutter section is set to a water gradient of -3% in a clockwise direction. [Figure 9] This is a cross-sectional view of the track bed and roadbed that make up the railway. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the undercutter device according to the present invention will be described in detail with reference to the accompanying drawings. Note that the undercutter device 1 of the embodiment described below is merely an example of the present invention, and the present invention is not limited to the following embodiment, and can be modified as appropriate within the scope of the technical concept of the present invention.

[0011] <Configuration of the undercutter device 1 according to the embodiment> As shown in Figures 1 to 8, the undercutter device 1 of the embodiment includes a coupler unit 11, a horizontal rotation mechanism unit 12, a cutter suspension support unit 13, an undercutter unit 14, an extension mechanism unit 15, etc.

[0012] (Coupler section 11) The coupler unit 11 is a portion that connects to an attachment mounting portion (not shown) at the tip of the working arm of a backhoe (not shown), and is composed of a coupler unit main body 11a that incorporates a driven gear (not shown), and a pair of pin connecting plates 11b, 11b, etc., that are provided on the upper surface of the coupler unit main body 11a at a predetermined distance and have three connecting pins: a common connecting pin 11b1, a small backhoe connecting pin 11b2, and a large backhoe connecting pin 11b3, so that it can be connected to both large and small backhoes (not shown). In other words, when connecting to the working arm of a large backhoe, the common connecting pin 11b1 and the large backhoe connecting pin 11b3 are used for connection, and when connecting to the working arm of a small backhoe, the common connecting pin 11b1 and the small backhoe connecting pin 11b2 are used for connection.

[0013] (Horizontal rotation mechanism 12) The horizontal rotation mechanism 12 is provided on the upper surface of the coupler body 11a of the coupler 11, and rotates a built-in drive gear (not shown) using hydraulic pressure or electric current sent from a backhoe (not shown), which in turn rotates a driven gear (not shown) provided on the upper surface of the turntable 13a of the cutter hanging support 13 (described later), thereby rotating the cutter hanging support 13 and the undercutter 14 parallel to the upper or lower surface of the coupler body 11a relative to the coupler 11.

[0014] (Cutter hanging support part 13) The cutter hanging support part 13 is rotatably connected to the coupler part 11, and rotates the undercutter part 14 in a plane parallel to the upper or lower surface of the coupler part main body 11a by the horizontal rotation mechanism part 12. It is composed of a turntable 13a rotated by the horizontal rotation mechanism part 12, a pair of legs 13b, 13b arranged at a predetermined interval on the lower surface of the turntable 13a, a plurality of outer leg reinforcing plates 13c, 13c (here, for example, three, but not limited to three) welded between the outer surfaces of the pair of legs 13b, 13b and the lower surface of the turntable 13a, and a plurality of inner leg reinforcing plates 13d, 13d (here, for example, three, but not limited to three) welded between the inner surfaces of the pair of legs 13b, 13b and the lower surface of the turntable 13a.

[0015] A driven gear (not shown) that meshes with a drive gear (not shown) of the rotation mechanism 12 is provided on the upper surface of the turntable 13a, and rotates in a plane parallel to the upper and lower surfaces of the turntable 13a.

[0016] In addition, on the underside of the turntable 13a and behind the pair of legs 13b, 13b, there is provided an extension mechanism upper end connection portion 13a1 to which the upper end of the nut body 15a (described later) of the extension mechanism portion 15 is rotatably connected, as shown in Figure 3, etc.

[0017] The pair of legs 13b, 13b are each welded to the underside of the turntable 13a, etc., and rotate horizontally together with the turntable 13a to rotate the undercutter section 14. At the lower end of each of the pair of legs 13b, 13b, closer to the tip of the undercutter section 14 than the center of the legs 13b, 13b in the longitudinal direction of the undercutter section 14, a leg side connecting section 13e is provided which is rotatably connected to the cutter side connecting section of the undercutter section 14 via a pivot shaft 13e1, and at the rear end of the undercutter section 14, a leg side abutment section 13f is provided which is not connected to the cutter side connecting section of the undercutter section 14, but abuts against an upwardly inclined stopper provided on the cutter side connecting section.

[0018] In addition, an upward inclined stopper 13g is provided on the end surface of the tip of the undercutter portion 14 of the pair of legs 13b, 13b, which abuts against the tip surface of a pair of cutter side connecting pieces 14b2, 14b2 of the cutter side connecting portion 14b described later when the tip of the undercutter portion 14 rises above the horizontal plane of the coupler portion 11 and tilts at a predetermined angle, for example, +3% or more of the water gradient angle.

[0019] The outer leg reinforcing plates 13c, 13c are reinforcing plates that are welded between the outer surfaces of the pair of legs 13b, 13b and the lower surface of the rotating disk 13a for reinforcement.

[0020] The inner leg reinforcing plates 13d, 13d are reinforcing plates that are welded between the inner surfaces of the pair of legs 13b, 13b and the lower surface of the rotating disk 13a for reinforcement.

[0021] (Undercutter part 14) The undercutter section 14 comprises an undercutter section main body 14a that excavates the construction base surface and the track bed 3 under the sleepers using a plurality of excavation claws 14a5 that move in a circular motion between an upper surface 14a1 and a lower surface 14a2, and a cutter side connecting section 14b that is provided on the upper surface 14a1 of the undercutter section main body 14a and is rotatably connected to the leg side connecting sections 13e of a pair of legs 13b, 13b of the cutter hanging support section 13 via a pivot shaft 13e1.

[0022] (Undercutter body 14a) As described above, the undercutter main body 14a is arranged so that the outer peripheral side surface is wrapped around between the upper surface 14a1 and the lower surface 14a2, and multiple excavation claws 14a5 and scraping plates 14a6 are arranged at predetermined intervals, and a chain belt 14a4 is provided that rotates along the outer peripheral side surface between the upper surface 14a1 and the lower surface 14a2 by a chain belt drive gear 14a3 (see Figure 4) on the base end (rear end) side that rotates by hydraulic pressure or electric current supplied from a backhoe (not shown).

[0023] As shown in Figures 1 and 2, the multiple excavation claws 14a5 are arranged alternately at a predetermined interval on the outside of the chain belt 14a4, facing diagonally upward and diagonally downward, and each excavation blade (cutter tip) is provided at the tip of the excavation claws 14a5 that protrude outward from the scraping plate 14a6, so that the construction base surface and the track bed 3 under the sleepers can be excavated not only when the chain belt 14a4 rotates in the forward direction, but also when it rotates in the reverse direction.

[0024] As shown in Figures 1, 2, 4, etc., the scraping plate 14a6 is provided adjacent to the excavation claws 14a5 at a predetermined distance outside the chain belt 14a4 so that the track bed 3 excavated by the excavation claws 14a5 can be scraped outward from the undercutter main body 13b not only when the excavation claws 14a5 rotate in the forward direction but also when the excavation claws 14a5 rotate in the reverse direction.

[0025] (cutter side connecting part 14b) The cutter side connecting portion 14b is provided with a cutter side connecting portion base plate 14b1 attached at four points to the base end side of the upper surface 14a1 of the undercutter main body 14a, and a pair of cutter side connecting pieces 14b2, 14b2 which are erected at a predetermined distance from the upper surface of the cutter side connecting portion base plate 14b1 and are rotatably connected via a pivot 13e1 to leg side connecting portions 13e, 13e provided at the lower ends of a pair of legs 13b, 13b of the cutter hanging support portion 13.

[0026] Here, on the rear side of the pair of cutter side connecting pieces 14b2, 14b2 on the cutter side connecting portion base plate 14b1, there is provided an extension mechanism lower end connecting portion 14b3 to which the lower end of the screw rod 15b of the extension mechanism portion 15, described later, is rotatably connected.

[0027] A downward inclination stopper 14b4 is provided at the rear end of the pair of cutter side connecting pieces 14b2, 14b2, i.e., between the connection point of the pair of cutter side connecting pieces 14b2, 14b2 with the pivot shaft 13e1 and the lower end connecting part 14b3 of the telescopic mechanism, against which the lower end surfaces of the pair of legs 13b, 13b abut when the tip side of the undercutter part 14 drops relative to the horizontal plane of the coupler part 11, causing the tip to incline downward at a predetermined angle, for example, a water gradient angle of -3% or more.

[0028] Furthermore, when the tip of the undercutter portion 14 rises above the horizontal plane of the coupler portion 11 and is inclined at a predetermined angle, for example, +3% or more of the water gradient angle, the tip surfaces of the pair of cutter side connecting pieces 14b2, 14b2 come into contact with upward inclination stoppers 13g provided at the lower ends of each of the pair of legs 13b, 13b.

[0029] (Extension mechanism section 15) The telescopic mechanism part 15 sets the tilt angle of the undercutter part 14 in the elevation direction to facilitate the work of forming a water gradient (see Figure 9) between the roadbed 2 and the trackbed 3, and is composed of a nut body 15a with a female thread part that is rotatably connected to the telescopic mechanism upper end connecting part 13a1 provided on the underside of the turntable 13a of the cutter hanging support part 13, as shown in Figure 3(a) etc., and a screw rod 15b whose lower end is rotatably connected to the telescopic mechanism lower end connecting part 14b3 and whose male thread part at the upper end screws into the female thread part of the nut body 15a.

[0030] <Operation of the undercutter device 1 of the embodiment> Next, the operation of the undercutter device 1 of the embodiment configured as above will be described.

[0031] (When excavating trackbed 3) First, when performing normal ballast excavation work to excavate the ballast 3 below the sleepers M that support the rails R, as shown in Figures 1 to 3, the extension mechanism 15 is set to its normal length and the angle of the upper surface 14a1 and lower surface 14a2 of the undercutter body 14a of the undercutter unit 14 is set parallel to the angle of the turntable 13a of the cutter hanging support unit 13.

[0032] Then, as in normal ballast excavation work, hydraulic pressure, electric current, etc. are supplied from a backhoe (not shown) to the undercutter device 1 to rotate the chain belt 14a4 of the undercutter main body 14a, and the ballast 3 under the construction base surface and the sleepers is excavated by multiple excavation claws 14a5 provided at predetermined intervals on the chain belt 14a4, and the ballast 3 excavated by the excavation claws 14a5 is scraped outward from the undercutter main body 13b by the scraping plate 14a6.

[0033] (When forming a water gradient of +3% clockwise between roadbed 2 and ballast 3) Next, when forming a water gradient of +3% clockwise between the roadbed 2 and the trackbed 3, that is, a water gradient that slopes downward to the right in Figure 9, the worker rotates the threaded rod 15b that is threaded into the female thread portion of the nut body 15a of the extension mechanism 15 as shown in Figures 5 and 6, thereby contracting the threaded rod 15b relative to the nut body 15a, and rotates the threaded rod 15b until the inclined stoppers 13g, 13g provided on the end faces on the tip side of the undercutter portion 14 of the pair of legs 13b, 13b reach the tip faces of the cutter side connecting piece portions 14b2, 14b2 of the cutter side connecting portion 14b as shown in Figure 6.

[0034] When the inclined stoppers 13g, 13g provided on the end faces of the tip of the undercutter section 14 of a pair of legs 13b, 13b abut the tip faces of the cutter side connecting piece portions 14b2, 14b2 of the cutter side connecting portion 14b, the angle of the upper surface 14a1 and lower surface 14a2 of the undercutter section main body 14a of the undercutter section 14 can be inclined by 1.72 degrees relative to the angle of the turntable 13a of the cutter hanging support part 13, and a water gradient angle of +3% can be set in the clockwise direction on the right side in Figure 9.

[0035] Then, as in normal ballast excavation work, hydraulic pressure, electric current, etc. are supplied from a backhoe (not shown) to the undercutter device 1 to rotate the chain belt 14a4 of the undercutter main body 14a, and the multiple excavation claws 14a5 attached to the chain belt 14a4 excavate the construction base surface and the ballast 3 under the sleepers, and the scraping plate 14a6 scrapes outward from the undercutter main body 13b the ballast 3 excavated by the excavation claws 14a5, forming a roadbed 2 with a water gradient angle of +3% between the roadbed 2 and the ballast 3.

[0036] (When forming a water gradient of -3% clockwise between roadbed 2 and ballast 3) On the other hand, when forming a water gradient of -3% clockwise between the roadbed 2 and the trackbed 3, that is, a water gradient that slopes downward to the left in Figure 9, the worker extends the threaded rod 15b from the nut body 15a by rotating the threaded rod 15b that is threaded into the female threaded portion of the nut body 15a of the extension mechanism 15 as shown in Figures 7 and 8 in the opposite direction to when forming a water gradient of +3% clockwise, and then rotates the threaded rod 15b in the reverse direction until the lower end surfaces of the pair of legs 13b, 13b abut against the downward inclined stoppers 14b4, 14b4 that are welded or otherwise provided to the pair of cutter side connecting pieces 14b2, 14b2 as shown in Figures 8(a) and (b).

[0037] When the lower end surfaces of the pair of legs 13b, 13b abut against the downward inclined stoppers 14b4, 14b4 which are welded or otherwise attached to the pair of cutter side connecting pieces 14b2, 14b2, the angle of the upper surface 14a1 and lower surface 14a2 of the undercutter main body 14a of the undercutter part 14 can be inclined by 1.72 degrees relative to the angle of the turntable 13a of the cutter hanging support part 13, making it possible to set a water gradient of -3% clockwise.

[0038] Then, as in normal ballast excavation work, hydraulic pressure, electric current, etc. are supplied from a backhoe (not shown) to the undercutter device 1 to rotate the chain belt 14a4 of the undercutter main body 14a, and the multiple excavation claws 14a5 attached to the chain belt 14a4 excavate the construction base surface and the ballast 3 under the sleepers, and the scraping plate 14a6 scrapes the ballast 3 excavated by the excavation claws 14a5 outward from the undercutter main body 13b, forming a ballast 2 with a water gradient of -3% in a clockwise direction between the roadbed 2 and the ballast 3.

[0039] <Summary of the undercutter device 1 according to the embodiment of the present invention> In the undercutter device 1 of the embodiment of the present invention, the leg side connecting portion 13e of the leg of the cutter hanging support portion 13 and the cutter side connecting portion 14b of the undercutter portion 14 are rotatably connected by a pivot shaft 13e1 extending parallel to the upper surface of the undercutter portion 14, and an extension mechanism portion 15 is provided in which both ends are rotatably connected to the cutter hanging support portion 13 and the undercutter portion 14, and which extends and contracts to rotate the undercutter portion 14 relative to the cutter hanging support portion 13 via the pivot shaft 13e1, thereby changing the angle of the undercutter portion 14.

[0040] Therefore, by extending and retracting the extension mechanism part 15, the under-cutter part 14 can be rotated around the pivot axis 13e1 relative to the cutter hanging support part 13 to change the angle, making it possible to easily set the water gradient (water cut-off gradient) on the roadbed upper surface (boundary surface) 2b between the roadbed 2 and the trackbed 3, thereby improving workability when setting the water gradient.

[0041] Furthermore, in the undercutter device 1 of the embodiment according to the present invention, the pivot shaft 13e1 is arranged eccentrically toward the tip of the undercutter section 14 relative to the center of the leg in the longitudinal direction of the undercutter section 14, and an upward inclination stopper 13g is provided on the end face of the leg sections 13b, 13b on the tip side of the undercutter section 14, which abuts against the end face of the cutter side connecting section 14b when the tip of the undercutter section 14 rises above the horizontal plane of the coupler section 11 and is inclined by a predetermined angle or more.

[0042] Therefore, the upward tilt stopper 13g prevents the tip of the undercutter portion 14 from tilting upward by more than a specified angle, so the angle (elevation angle) of the undercutter portion 14 can be set safely, improving work efficiency.

[0043] Furthermore, in the undercutter device 1 of the embodiment according to the present invention, the pivot shaft 13e1 is arranged eccentrically toward the tip of the undercutter section 14 relative to the center of the legs 13b, 13b in the longitudinal direction of the undercutter section 14, and a downward inclination stopper 14b4 is provided on the extension mechanism section 15 side relative to the connection point with the pivot shaft 13e1 in the cutter side connection section 14b, which abuts against the leg side abutment section 13f at the bottom of the legs 13b, 13b when the undercutter section 14 is inclined downward at the tip by more than a predetermined angle due to the tip side of the undercutter section 14 lowering relative to the horizontal plane of the coupler section 11.

[0044] Therefore, the downward inclination stopper 14b4 prevents the tip of the undercutter portion 14 from inclining downward by more than a predetermined angle, so the angle (elevation angle) of the undercutter portion 14 can be safely set, improving work efficiency.

[0045] In addition, in the undercutter device 1 of the embodiment of the present invention, the predetermined angle when the upward inclined stopper 13g abuts against the end face of the cutter side connecting portion 14b and the predetermined angle when the downward inclined stopper 14b4 abuts against the leg side abutment portion 13f at the lower part of the legs 13b, 13b are set to the angle of the water gradient to be set between the roadbed 2 and the trackbed 3.

[0046] Therefore, by using the upward inclination stopper 13g and the downward inclination stopper 14b4, it becomes possible to easily set a water gradient on the roadbed upper surface (boundary surface) 2b between the roadbed 2 and the trackbed 3, thereby improving workability when setting up the water gradient.

[0047] In addition, in the undercutter device 1 of the embodiment of the present invention, the pivot axis 13e1 is provided on the tip side of the undercutter section 14 on the leg sections 13b, 13b, while the extension mechanism section 15 is provided on the base end (rear end) side of the undercutter section 14.

[0048] Therefore, when changing the angle (elevation angle) of the undercutter section 14, the extension mechanism section 15 can be operated at the base end (rear end) side of the undercutter section 14, which protrudes less from the legs 13b, 13b, thereby improving work efficiency in this respect as well.

[0049] In addition, in the undercutter device 1 of the embodiment of the present invention, the extension mechanism part 15 is composed of a nut body 15a having a female threaded portion and one end of which is rotatably connected to the underside of the cutter hanging support part 13, and a threaded rod 15b having a male threaded portion and one end of which is rotatably connected to the upper surface of the undercutter part 14, and the other end of which screws into the female threaded portion of the nut body 15a.

[0050] Therefore, the angle (elevation angle) of the undercutter part 14 can be adjusted by the extension mechanism part 15 having a simple structure, and in this respect too, the work efficiency can be improved.

[0051] In particular, when setting the angle (elevation angle) of the undercutter section 14, the nut body 15a operated by the worker is provided on the upper cutter hanging support section 13 side rather than the lower undercutter section 14 side, making it easier to operate the nut body 15a, and since the threaded rod 15b protrudes from the lower end of the nut body 15a, it is less likely that crushed stone, mud, garbage, etc. will get in between the nut body 15a and the threaded rod 15b, which also makes it easier to operate the nut body 15a and improves work efficiency.

[0052] In the above embodiment, the telescopic mechanism 15 is described as being composed of a nut body 15a and a threaded rod 15b, but the present invention is not limited to this and any mechanism that can be extended and retracted to change the angle of the undercutter portion 14 is acceptable. For example, the telescopic mechanism may be composed of a cylinder with an extendable piston or an adjustment plate with a long hole, and pins or screws fixed at any or multiple predetermined positions in the long hole. [Explanation of symbols]

[0053] 1 Undercutter device 11 Coupler Section 11a Coupler body 11b Coupler body 11b1 Common connecting pin 11b2 Small backhoe connecting pin 11b3 Large backhoe connecting pin 12 Horizontal rotation mechanism 13 Cutter hanging support 13a Turntable 13a1 Upper end connection part of telescopic mechanism 13b Legs 13c Outer leg reinforcement plate 13d Inner leg reinforcement plate 13e Leg side connection part 13e1 Rotating shaft 13f Leg side contact part 13g upward tilt stopper 14 Undercutter section 14a Undercutter body 14a1 Top side 14a2 Bottom side 14a3 Chain belt drive gear 14a4 chain belt 14a5 digging claw 14a6 scraping plate 14b Cutter side connection part 14b1 Cutter side connection base plate 14b2 Cutter side connecting piece 14b3 Lower end connection part of telescopic mechanism 14b4 Downward Slope Stopper 15 Telescopic mechanism section 15a nut body 15b threaded rod 2 Roadbed 2a Railroad gutter 3 Road bed R rail M sleeper

Claims

1. A coupler portion connected to an attachment mounting portion at the tip of the working arm of the backhoe; a cutter hanging support part that is rotatably connected to the coupler part and has a leg part that extends downward; an undercutter unit connected to the leg-side connecting portion of the leg portion via a cutter-side connecting portion and excavating the ballast by moving a plurality of excavation claws; The leg-side connecting portion and the cutter-side connecting portion are rotatably connected by a rotation axis extending parallel to the upper surface of the undercutter portion, and an extension mechanism portion is provided whose both ends are rotatably connected to the cutter hanging support portion and the undercutter portion, By extending and retracting the extension mechanism, the undercutter unit rotates relative to the cutter hanging support unit via the rotation shaft to change the angle of the undercutter unit, The rotation shaft is provided eccentrically toward the tip end of the undercutter with respect to the center of the leg in the longitudinal direction of the undercutter, An upward inclination stopper is provided on the end surface of the leg portion at the tip side of the undercutter portion, and when the tip side of the undercutter portion rises with respect to the horizontal plane of the coupler portion and is inclined at a predetermined angle or more, the upward inclination stopper abuts against the end surface of the cutter side connecting portion, An undercutter device characterized in that the predetermined angle is the angle of the water gradient between the roadbed and the ballast.

2. A coupler portion connected to an attachment mounting portion at the tip of the working arm of a backhoe; a cutter hanging support part that is rotatably connected to the coupler part and has a leg part that extends downward; an undercutter unit connected to the leg-side connecting portion of the leg portion via a cutter-side connecting portion and excavating the ballast by moving a plurality of excavation claws; The leg-side connecting portion and the cutter-side connecting portion are rotatably connected by a rotation axis extending parallel to the upper surface of the undercutter portion, and an extension mechanism portion is provided whose both ends are rotatably connected to the cutter hanging support portion and the undercutter portion, By extending and retracting the extension mechanism, the undercutter unit rotates relative to the cutter hanging support unit via the rotation shaft to change the angle of the undercutter unit, The rotation shaft is provided eccentrically toward the tip end of the undercutter with respect to the center of the leg in the longitudinal direction of the undercutter, A downward inclination stopper is provided on the telescopic mechanism side relative to the connection point with the pivot shaft of the cutter side connection part, against which the lower end surface of the leg part abuts when the tip side of the undercutter part is lowered with respect to the horizontal plane of the coupler part and the tip is inclined downward by a predetermined angle or more, An undercutter device characterized in that the predetermined angle is the angle of the water gradient between the roadbed and the ballast.

3. The undercutter device according to claim 1 or 2, The undercutter device is characterized in that the telescopic mechanism is composed of a nut body having a female thread portion, one end of which is rotatably connected to the underside of the cutter hanging support part, and a threaded rod having a male thread portion, one end of which is rotatably connected to the upper side of the undercutter part, and the other end of which screws into the female thread portion of the nut body.

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