CN210395488U

CN210395488U - Ditching machine for pipeline laying

Info

Publication number: CN210395488U
Application number: CN201921031180.4U
Authority: CN
Inventors: 石川; 杨熙; 张靖; 杨波; 肖修武
Original assignee: Sinohydro Bureau 9 Co Ltd
Current assignee: Sinohydro Bureau 9 Co Ltd
Priority date: 2019-07-04
Filing date: 2019-07-04
Publication date: 2020-04-24
Anticipated expiration: 2029-07-04

Abstract

The utility model provides a ditching machine for laying pipelines, which belongs to the technical field of municipal pipe network construction and comprises a frame, a cutter chain frame, an excavating part, a lifting mechanism, a control panel and a remote controller, wherein the frame is provided with a driving part and a traveling wheel; one end of the cutter chain frame is hinged with the rack through a hinge; the digging part comprises a driving chain wheel, a driven chain wheel and a cutter chain, and a ditching cutter is arranged on the cutter chain; the lifting mechanism is used for pushing the cutter chain frame to rotate; the soil pushing mechanism is used for pushing the earthwork; the control panel is provided with a controller and a first wireless communication module, the traveling wheels move by means of a driving part, and the first motor, the hydraulic oil cylinder and the driving part are all controlled by the controller; the remote controller is provided with a second wireless communication module for sending instructions to the controller. The depth of the trench pre-excavated by the ditcher and the walking speed of the walking wheels are controllable, the depth of ditching is controllable, the ditcher is convenient to move, the ditcher is convenient to use in a narrow space, the construction efficiency is high, and the progress is fast.

Description

Ditching machine for pipeline laying

Technical Field

The utility model belongs to the technical field of municipal pipe network construction, more specifically say, relate to a pipeline is laid and is used ditching machine.

Background

In municipal pipe network construction, especially the construction of laying of water supply line, often use large-scale ditching machinery to carry out the ditching operation to the highway section of laying in advance, so that burying underground of water supply line, when construction in some narrow highway sections or the limited occasion in space, because large-scale ditching machinery is bulky, generally advance for the crawler-type, it is inconvenient to remove, the ditch depth of digging out differs, cause the influence to the construction, then need the manual work to carry out the ditching operation of digging, not only take a lot of work but also take time, low working efficiency and with high costs, large-scale ditching machinery also can't adapt to the ground of multiple different environment.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a pipe laying uses ditching machine aims at solving and digs the ditch degree of depth in the construction of running water pipe network and differs, removes inconveniently, technical problem that the efficiency of construction is low.

In order to achieve the above object, the utility model adopts the following technical scheme: provided is a trencher for laying a pipeline, comprising:

the upper end of the frame is provided with a driving part, and the bottom of the frame is provided with a plurality of travelling wheels;

one end of the cutter chain frame is hinged with the rack through a hinge, and the other end of the cutter chain frame is a free end;

the digging part is arranged on the cutter chain frame and used for digging a groove and comprises a driving chain wheel, a driven chain wheel and a cutter chain wound between the driving chain wheel and the driven chain wheel, a plurality of digging cutters are arranged on the cutter chain along the length direction of the cutter chain, and the driving chain wheel rotates by means of a first motor;

the lifting mechanism is arranged above the cutter chain frame, is used for pushing the cutter chain frame to rotate, and comprises a hydraulic oil cylinder, one end of the hydraulic oil cylinder is hinged with the cutter chain frame, and the other end of the hydraulic oil cylinder is hinged with the rack;

the bulldozing mechanism is arranged on the side part of the cutter chain frame and used for pushing the earthwork excavated by the excavating part to the side part of the cutter chain frame, and the bulldozing mechanism is fixedly connected to the driving chain wheel and synchronously rotates along with the driving chain wheel;

the control panel is arranged on the rack and is provided with a controller and a first wireless communication module electrically connected with the controller, the travelling wheel moves by means of a driving part, and the first motor, the hydraulic oil cylinder and the driving part are all controlled by the controller;

and the remote controller is provided with a second wireless communication module, and transmits signals to the first wireless communication module through the second wireless communication module so as to send instructions to the controller.

Further, the driving part comprises a second motor, a speed reducer connected with a power output end of the second motor, a driving wheel connected with a power output end of the speed reducer and a driven wheel in transmission connection with the driving wheel, the driven wheel is connected with the traveling wheel through a belt, and the second motor is controlled by the controller.

Further, the walking wheel comprises two large wheels which are arranged side by side and coaxially and two small wheels which are arranged side by side and coaxially, the large wheels are connected with the driven wheels, and the top ends of the small wheels are rotatably connected with the rack by means of wheel carriers.

Further, a soil blocking plate is arranged above the cutter chain frame and used for preventing soil excavated by the excavating part from entering the upper part of the cutter chain frame.

Furthermore, a traction frame used for being connected with traction equipment is arranged at the end part of the machine frame, and the traction frame is connected with the wheel frame above the small wheel and synchronously swings relative to the machine frame with the small wheel to control the traction direction.

Furthermore, the lifting mechanism also comprises a first support and a second support, wherein one end of the first support is fixedly arranged on the cutter chain frame, and the other end of the first support is hinged with the pushing end of the hydraulic oil cylinder; one end of the second support is fixed on the rack, and the other end of the second support is hinged with the fixed end of the hydraulic oil cylinder.

Furthermore, the ditching machine for pipeline laying still includes tight chain mechanism, tight chain mechanism including set firmly in tight chain frame on the sword chain frame is located with rotating tight sprocket on the tight chain frame, tight chain frame includes upper bracket and lower carriage, the upper bracket lower extreme with the lower carriage upper end all is equipped with the threaded rod, connects through the nut of looks adaptation between two threaded rods, tight sprocket is used for pushing against the sword chain, tight sprocket with the inboard sliding contact of sword chain and tensioning the sword chain.

Furthermore, the ditching cutter comprises a main cutter and an auxiliary cutter, and blades are arranged on the main cutter and the auxiliary cutter.

Furthermore, the cutter chain frame, the digging part, the bulldozing mechanism, the driving wheel and the driven wheel are arranged in two sets and are symmetrically arranged along the central line of the rack, the lifting mechanism synchronously drives the two sets of cutter chain frames to lift, and the driven wheel is respectively connected with the large wheel on the corresponding side through a belt.

Further, the dozing mechanism includes a rotation shaft connected to the drive sprocket and a helical blade provided on the rotation shaft, and the rotation shaft is rotated by the drive sprocket.

The utility model provides a pair of ditching machine for pipeline laying's beneficial effect lies in: compared with the prior art, the utility model relates to a pipe laying uses ditching machine, the sword chain frame is articulated with the frame, can adjust the lift height of sword chain frame through elevating system, bulldozing mechanism can push away the soil direction both sides and remove, so as not to influence the ditching structure, the walking progress of frame can be controlled respectively to the controller, drive sprocket's excavation dynamics and hydraulic cylinder's promotion length, and then the degree of depth of control slot of digging in advance and the walking speed of walking wheel, it differs to have solved the ditching degree of depth in the construction of running water pipe network, it is inconvenient to remove, the technical problem that the efficiency of construction is low, it is controllable to the degree of depth of ditching, the ditching machine removes conveniently, be convenient for use in narrow and small space, high construction efficiency, the fast technological effect of progress.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural view of a ditcher for laying pipelines according to an embodiment of the present invention;

fig. 2 is a top view of a ditcher for laying a pipeline according to an embodiment of the present invention;

fig. 3 is a schematic view of a partial structure of an excavating part of a ditcher for laying pipelines according to an embodiment of the present invention;

fig. 4 is a schematic structural view of a chain tightening mechanism of a ditcher for pipeline laying according to an embodiment of the present invention.

In the figure: 1. a frame; 11. a traction frame; 12. an illumination device; 13. a support; 2. a cutter chain frame; 21. a hinge; 22. a soil guard plate; 3. an excavating part; 31. a drive sprocket; 32. a driven sprocket; 33. a cutter chain; 34. digging a furrow cutter; 341. a main knife; 342. a secondary knife; 343. a blade; 4. a lifting mechanism; 41. a hydraulic cylinder; 42. a first bracket; 43. a second bracket; 5. a bulldozing mechanism; 51. a rotating shaft; 52. a helical blade; 6. a control panel; 7. a drive section; 71. a second motor; 72. a speed reducer; 73. a driving wheel; 74. a driven wheel; 8. a traveling wheel; 81. a bull wheel; 82. a small wheel; 9. a chain tightening mechanism; 91. a chain tightening frame; 911. putting on a shelf; 912. putting down a rack; 913. a nut; 92. tightening the chain wheel; 10. and a remote controller.

Detailed Description

In order to make the technical problem, technical solution and advantageous effects to be solved by the present invention more clearly understood, the following description is given in conjunction with the accompanying drawings and embodiments to illustrate the present invention in further detail. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1 to 4, a trencher for pipeline construction according to the present invention is illustrated, which includes a frame 1, a cutter chain frame 2, an excavating part 3, a lifting mechanism 4, a soil-shifting mechanism 5, a control panel 6 and a remote controller 10.

The upper end of the frame 1 is provided with a driving part 7, the bottom of the frame is provided with a plurality of walking wheels 8, and the walking wheels 8 are driven by the driving part 7 to move forwards.

One end of the cutter chain frame 2 is hinged with the frame 1 through a hinge 21, the other end of the cutter chain frame 2 is a free end, and the rotation angle of the cutter chain frame 2 is adjusted by means of the lifting mechanism 4.

The digging part 3 is arranged on the cutter chain frame 2 and is used for digging a groove and comprises a driving chain wheel 31, a driven chain wheel 32 and a cutter chain 33 wound between the driving chain wheel 31 and the driven chain wheel 32, a plurality of digging cutters 34 are arranged on the cutter chain 33 along the length direction of the cutter chain 33, and the driving chain wheel 31 is rotated by means of a first motor; the excavation portion 3 is a main performing member for excavating a trench, and is capable of excavating a trench from a soil layer and discharging earth outside the trench.

The lifting mechanism 4 is arranged above the cutter chain frame 2, is used for pushing the cutter chain frame 2 to rotate, and comprises a hydraulic oil cylinder 41, one end of the hydraulic oil cylinder is hinged with the cutter chain frame 2, and the other end of the hydraulic oil cylinder is hinged with the rack 1; the lifting mechanism 4 can adjust the rotation angle of the cutter chain frame 2 so as to adjust the excavating depth of the excavating part 3, and the hydraulic oil cylinder 41 controls the rotation of the cutter chain frame 2 to be stable.

The soil pushing mechanism 5 is arranged at the side part of the cutter chain frame 2 and used for pushing the excavated earthwork of the excavating part 3 to the side part of the cutter chain frame 2, the soil pushing mechanism 5 is fixedly connected to the driving chain wheel 31 and synchronously rotates with the driving chain wheel 31, and after the excavating part 3 excavates a soil layer out of a groove, the earthwork is arranged to the side part of the cutter chain frame 2 along the soil pushing mechanism 5, so that the excavated earthwork is not retained in the groove.

The control panel 6 is arranged on the rack 1 and is provided with a controller and a first wireless communication module electrically connected with the controller, the traveling wheels 8 move by means of a driving part 7, and the first motor, the hydraulic oil cylinder 41 and the driving part 7 are all controlled by the controller.

The remote controller 10 is provided with a second wireless communication module, and the remote controller 10 transmits a signal to the first wireless communication module through the second wireless communication module to send an instruction to the controller.

The utility model provides a pair of ditching machine for pipeline laying, compared with the prior art, sword chain frame 2 is articulated with frame 1, can adjust the height-adjusting of sword chain frame 2 through elevating system 4, bulldoze the mechanism 5 and can promote the earthwork and remove towards the lateral part of sword chain frame 2, so as not to influence the ditching structure, the walking progress of frame 1 can be controlled respectively to the controller, drive sprocket 31's excavation dynamics and hydraulic cylinder 41's promotion length, and then control the degree of depth of the slot of excavating in advance and the walking speed of walking wheel 8, the ditching degree of depth is not uniform in running water pipe network construction has been solved, it is inconvenient to remove, the low technical problem of efficiency of construction, it is controllable to the degree of depth of ditching, the ditching machine removes conveniently, be convenient for use in narrow and small space, high efficiency of construction, the fast technical effect of progress, the function of remote controller 10 is used for remote control, can realize walking wheel, The drive sprocket 31 and the hydraulic cylinder 41 operate and control.

In a specific embodiment, the frame 1 is welded in a frame type structure, a plurality of traveling wheels 8 are arranged at the bottom of the frame 1, and preferably, the number of the traveling wheels 8 is 4. The cutter chain frame 2 is formed by welding a long strip-shaped frame structure. The driving sprocket 31 and the driven sprocket 32 of the digging part 3 are both connected to the cutter chain frame 2 and can rotate, the driving sprocket 31 rotates by means of a first motor, the first motor is arranged on the cutter chain frame 2, the trenching cutter 34 is fixedly arranged on the cutter chain 33 through transmission of the cutter chain 33, a sharp cutting edge 343 is arranged on the trenching cutter 34, the soil layers with different structures can be cut by the translation of the trenching cutter 34, and the earthwork is dug out well. The lifting mechanism 4 can lift the excavation portion 3, and the excavation depth of the excavation portion 3 can be controlled by controlling the extension length of the hydraulic cylinder 41. The dozing mechanism 5 is an indispensable component on the ditcher, and its effect is to discharge the earthwork excavated through the excavation portion 3 to the both sides of slot, makes the structure that does not influence the slot, and the dozing mechanism 5 is direct to be connected with the axle of driving sprocket 31, and the rotation of driving sprocket 31 drives the rotation of dozing mechanism 5 self to can make the earthwork discharge the slot. The controller sets the running distance of the running wheels 8, the rotating speed of the driving chain wheel 31 and the operation action control parameters of the extension length of the hydraulic oil cylinder 41 to complete the ditching and depth adjustment of the ditcher, the running of the frame 1 and other execution actions. The first wireless communication module can realize the wireless communication of the controller, and can also control the running distance of the travelling wheels 8, the rotating speed of the driving chain wheel 31 and the operation action of the extending length of the hydraulic oil cylinder 41 in the external space by means of the remote controller 10.

As a specific implementation manner of the ditching machine for pipeline laying, please refer to fig. 1 to 2, the driving portion 7 includes the second motor 71, the speed reducer 72 connected with the power output end of the second motor 71, the driving wheel 73 connected with the power output end of the speed reducer 72 and the driven wheel 74 in transmission connection with the driving wheel 73, the driven wheel 74 is connected with the walking wheel 8 through the belt, and the second motor 71 is controlled by the controller. The reducer 72, the driving wheel 73 and the driven wheel 74 are driven to rotate in sequence through the power output of the second motor 71, and the power transmission is stable and smooth.

In one embodiment, the second motor 71 is a servo motor, a large wheel body and a small wheel body are disposed on the driving wheel 73, a belt transmission mode or a belt transmission mode is adopted between the speed reducer 72 and the large wheel body of the driving wheel 73, and a chain transmission mode or a belt transmission mode is adopted between the small wheel body of the driving wheel 73 and the driven wheel 74, so that power transmission is stable.

As a specific embodiment of a ditching machine for pipeline laying, please refer to fig. 1-2, walking wheel 8 includes two bull wheels 81 and two steamboats 82 that just set up coaxially side by side and side by side, bull wheel 81 with from driving wheel 74 to be connected, steamboat 82 top is rotated with the help of the wheel carrier and frame 1 and is connected. Compared with crawler-type walking, the walking wheels 8 can walk fast and stably, and the small wheels 82 can rotate, so that the walking wheels can help to guide the traveling direction of the rack 1.

As a specific embodiment of the present invention, please refer to fig. 1 to 2, the top of the cutter chain frame 2 is further provided with a retaining plate 22, and the retaining plate 22 is used to prevent the earth excavated by the excavating part 3 from entering the top of the cutter chain frame 2. The earthwork can be taken away along the cutter chain 33 in the excavation process, and the earth excavated by the excavation part 3 can be shielded by the retaining plate 22, so that the earth is prevented from entering the upper part of the cutter chain frame 2, and the excavation efficiency and progress are improved.

As a specific embodiment of the ditching machine for pipeline laying, please refer to fig. 1 to 2, the end of the frame 1 is provided with a traction frame 11 for connecting a traction device, and the traction frame 11 is connected to the wheel carrier above the small wheel 82 and swings relative to the frame 1 synchronously with the small wheel 82 for controlling the traction direction. When the trench needs to be moved after a section of trench is dug, the trench needs to be pulled by equipment such as a tractor, during pulling, the traction frame 11 needs to be hung on a bracket of the tractor, then the pipeline ditcher can move, the pipeline ditcher can move flexibly, when the trench is moved by the traction equipment, the connection between the driven wheel 74 and the bull wheel 81 can be temporarily removed, after the trench is in place, the connection of the traction equipment is removed, then the trench is excavated by moving under the driving of the bull wheel 81, at the moment, the traction frame 11 can be manually controlled to guide, so that the trend of the trench is determined, and the connection traction equipment is suitable for long-distance position movement.

As a specific embodiment of the ditcher for pipeline laying provided by the present invention, please refer to fig. 1 to 2, the lifting mechanism 4 further includes a first bracket 42 and a second bracket 43; one end of the first bracket 42 is fixedly arranged on the cutter chain frame 2, and the other end is hinged with the pushing end of the hydraulic oil cylinder 41; one end of the second bracket 43 is fixed on the frame 1, and the other end is hinged with the fixed end of the hydraulic oil cylinder 41. The hydraulic oil cylinder 41 is driven by the control of the controller, the hydraulic oil cylinder 41 is an execution component, and a hydraulic pump station can be arranged on the frame 1 and used for providing hydraulic oil for the hydraulic oil cylinder 41 and helping to push the knife chain frame 2 to rotate.

As a pair of the utility model provides a pair of ditching machine for pipe laying please refer to fig. 1 and 4, ditching machine for pipe laying still includes tight chain mechanism 9, tight chain mechanism 9 is including setting firmly tight chain frame 91 on sword chain frame 2 and rotating the tight sprocket 92 of locating on tight chain frame 91, tight chain frame 91 includes upper bracket 911 and lower bracket 912, upper bracket 911 lower extreme and lower bracket 912 upper end all are equipped with the threaded rod, connect through the nut 913 of looks adaptation between two threaded rods, tight sprocket 92 is used for ejection sword chain 33, tight sprocket 92 and the inboard sliding contact of sword chain 33 and tensioning sword chain 33. The chain tightening mechanism 9 is an auxiliary component for tightening the cutter chain 33, and after the cutter chain 33 is loosened, the chain tightening wheel 92 can be moved outward by manually operating the chain tightening structure, that is, by screwing the nut 913, so as to jack up and tighten the loosened cutter chain 33, thereby facilitating the execution of the digging part 3.

In one embodiment, the upper frame 911 and the lower frame 912 are connected through the nut 913, and the nut 913 is screwed to adjust the distance between the upper frame 911 and the lower frame 912, so that the supporting height of the tightening sprocket 92 can be adjusted, the cutter chain 33 is jacked up and tensioned, the inner side of the cutter chain 33 can contact and rub with the tightening sprocket 92, the tensioning force of the cutter chain 33 is increased, and the excavation earthwork construction of the excavation portion 3 is facilitated.

As a specific embodiment of the ditcher for pipeline laying according to the present invention, please refer to fig. 3, the trenching knife 34 includes a main knife 341 and an auxiliary knife 342, and the main knife 341 and the auxiliary knife 342 are both provided with a cutting edge 343. The main blade 341 is a main actuator, and the sub-blade 342 is an auxiliary actuator that is auxiliary to the main blade 341 and can cut earth.

In one embodiment, the cutting edge 343 is made of cemented carbide material and is wear resistant and durable.

As a specific implementation manner of the ditcher for pipeline laying provided by the present invention, please refer to fig. 1 to 2, the cutter chain frame 2, the digging part 3, the bulldozing mechanism 5, the driving wheel 73 and the driven wheel 74 are two sets and symmetrically arranged with respect to the center line of the frame 1, the lifting mechanism synchronously drives the two sets of cutter chain frames 2 to lift, the driven wheel 74 is respectively connected with the large wheel 81 at the corresponding side through the belt, the driving wheel 73 and the driven wheel 74 are also two sets, and are divided into two sets of same transmission systems and symmetrically arranged through the output of the reducer 72, and the power transmission route is as follows; the second motor 71, the speed reducer 72, the driving wheel 73, the driven wheel 74 and the large wheel 81, the two sets of the digging parts 3 are driven by one first motor respectively, and when two sets of the digging parts 3 are needed, the two sets can be used simultaneously; when one set of transmission system is needed, one set of transmission system can be used and the other set of transmission system can be stopped by operating the controller.

As a specific embodiment of the ditcher for pipeline laying according to the present invention, please refer to fig. 1 to 2, the soil shifter 5 includes a rotation shaft 51 connected to the driving sprocket 31 and a helical blade 52 disposed on the rotation shaft 51, and the rotation shaft 51 rotates by means of the driving sprocket 31. The rotation of the driving sprocket 31 can drive the rotation shaft 51 to rotate, the rotation shaft 51 can drive the helical blade 52 to rotate, and the earthwork at the two sides of the cutter chain frame 2 can push the earthwork outwards along the rotation direction of the helical blade 52, so that the earthwork can be pushed outwards, and the excavated groove forming protection is facilitated.

In one embodiment, the rotation speed of the spiral blade 52 is identical to the rotation speed of the driving sprocket 31, and the outer diameter of the spiral blade 52 is twice the diameter of the rotating shaft 51.

As a specific embodiment of the ditcher for pipeline laying provided by the present invention, please refer to fig. 1, the frame 1 is further provided with an illumination device 12 for night illumination, and the illumination device 12 is fixed on the frame 1 through a bracket 13.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. A ditcher for pipeline laying, comprising:

2. The ditcher as claimed in claim 1, wherein the driving part comprises a second motor, a speed reducer connected to a power output end of the second motor, a driving wheel connected to a power output end of the speed reducer, and a driven wheel in transmission connection with the driving wheel, the driven wheel is connected to the driving wheel through a belt, and the second motor is controlled by a controller.

3. A ditcher as claimed in claim 2, wherein the travelling wheels comprise two large wheels arranged side by side and coaxially and two small wheels arranged side by side and coaxially, the large wheels are connected with the driven wheels, and the top ends of the small wheels are rotatably connected with the frame by means of wheel carriers.

4. A trencher for laying a pipeline as claimed in claim 1 wherein a retaining plate is further provided above said blade carrier, said retaining plate preventing earth excavated through the excavation portion from entering above said blade carrier.

5. A trencher for laying pipelines as claimed in claim 3 wherein said frame is provided at an end thereof with a traction frame for connection to a traction apparatus, said traction frame being connected to a wheel carriage above said wheels and oscillating relative to said frame in synchronism with said wheels for controlling the direction of traction.

6. A ditcher as claimed in claim 1, wherein said lifting mechanism further comprises a first support and a second support, one end of said first support being fixed to said cutter chain frame and the other end being hinged to a pushing end of said hydraulic cylinder; one end of the second support is fixed on the rack, and the other end of the second support is hinged with the fixed end of the hydraulic oil cylinder.

7. A ditcher as claimed in claim 1, further comprising a chain tightening mechanism, wherein the chain tightening mechanism comprises a chain tightening frame fixed on the cutter chain frame and a chain tightening wheel rotatably arranged on the chain tightening frame, the chain tightening frame comprises an upper frame and a lower frame, threaded rods are arranged at the lower end of the upper frame and the upper end of the lower frame, the two threaded rods are connected through nuts, the chain tightening wheel is used for pushing against the cutter chain, and the chain tightening wheel is in sliding contact with the inner side of the cutter chain and tightens the cutter chain.

8. A trenching machine as claimed in claim 1 wherein said trenching blade comprises a primary blade and a secondary blade, said primary blade and said secondary blade each having a cutting edge.

9. A ditcher as claimed in claim 3, wherein the cutter chain holder, the digging part, the dozing mechanism, the driving wheel and the driven wheel are provided in two sets and symmetrically arranged with respect to the center line of the frame, the lifting mechanism synchronously drives the two sets of cutter chain holders to lift, and the driven wheel is connected to the large wheel on the corresponding side through a belt.

10. A trencher for laying a pipeline as claimed in claim 1 wherein said dozing mechanism comprises a rotary shaft connected to said drive sprocket and a helical blade provided on said rotary shaft, said rotary shaft being rotated by said drive sprocket.