JPS5976335A - Trench excavator - Google Patents

Abstract

PURPOSE:To excavate a trench while preventing sideward sliding on steep slope by a method in which a vertically movable trench runner is attached to the lower part of a running vehicle having a trencher on its front, and a runner on the land is also attached to the running vehicle in a vertically movable manner. CONSTITUTION:Four wheels 12 to support a running vehicle 2 while running on the land are separately attached to the running vehicle 2 in a vertically movable manner. A trench runner 96 to run on the bottom of a trench 64 excavated is attached to the central lower part of the vehicle 2 in a vertically movable manner. A trencher 40 is also attached to the front of the vehicle 2 in a vertically movable manner. In excavating a trench in steep slope in the mountaineous and hill areas, the excavation can be exactly and safely attained without the use of the runner 12 on the land and also without causing sideward sliding and sideward drifting of the vehicle 2 on ungraded ground, etc., because the trench runner 96 is used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a trench excavator that makes it possible to construct continuous trenches on steep slopes such as mountains and hills.

Normally, when trench excavators are used to excavate trenches on steep slopes with irregular ground surfaces such as mountains and hills, when the excavating equipment is traversed across the slope, the vehicle that propels or guides the excavating equipment skids or drifts toward the valley side. This made it difficult to excavate on relatively gentle slopes (up to an inclination of about 15°) due to slipping when climbing over obstacles.

In addition, for this type of trench excavator, the ground height of the left and right suspension legs can be changed independently, in other words, the valley side leg is extended high and the mountain side leg is shortened low to keep the traveling body horizontal and excavate along the lateral direction of the slope. However, even with these methods, it is still impossible to avoid skidding 9 etc. on steep slopes with uneven ground surfaces. This was limited to cases where there were few irregularities and the frictional holding force was good. In this way, during excavation work along the lateral direction of a slope, it is a fatal flaw for the traveling vehicle body on which the excavation equipment is attached to skid, and it is especially difficult to excavate trenches along the same height. When trench excavation is carried out continuously using a trencher or the like, problems such as damage to the equipment itself or loss of integrity of the excavated trench occur.

Therefore, in order to prevent the vehicle from skidding, etc. and improve its ability to run on uneven terrain, measures such as sufficiently lowering the ground pressure of the suspension system of the vehicle or increasing the number or size of wheels are adopted. However, on sloped surfaces that are locally uneven, or on wet grass surfaces that become slippery due to low ground pressure, the vehicle width axis may skid or drift laterally when driving on these terrains. It was not possible to prevent this, and there was a safety problem.

In addition, conventional continuous groove excavators are difficult to excavate straight grooves, and it is difficult to excavate curved grooves, and it is even more difficult when the excavation groove is deep. It is not suitable for excavating detour ditches to avoid obstacles such as rocks, trees, roads, streams, etc., turn-around ditches that turn around without interrupting the ditch, and ditches that surround features, and has the drawback of lacking versatility. are doing.

The present invention has been made in view of the above-mentioned drawbacks of the conventional technology, and its first purpose is to provide a movable groove traveling device at the bottom of a traveling vehicle body, and to drive this device in an excavated trench. This prevents the vehicle body from skidding or drifting on steep slopes with uneven or poor ground surfaces in mountains, hills, etc., ensuring work safety and making it possible to excavate continuous deep trenches. Our goal is to provide the following.

A second object of the present invention is to install an excavation device and a groove traveling device on a traveling vehicle body such that they can be raised and lowered and rotated in a horizontal plane, thereby making it possible to drill, for example, in curved grooves along a uniform height, in rock formations, etc. ,
Excavation of trenches to bypass obstacles such as trees, etc. due to terrain, slope, etc.
To provide a trench excavator which can be safely and easily excavated without being affected by obstacles.

Furthermore, a third object of the present invention is to hold the traveling vehicle body horizontally by means of traveling devices which are provided on both sides of the traveling vehicle body, travel on the ground, and are individually raised and lowered.
The present invention will now be described in detail based on embodiments shown in the drawings. on 11
to see clearly.

Fig. 1 (J: Partially omitted side sectional view in the 4ii cutting state showing an embodiment of the i'4 excavator according to the present invention, Fig. 2 is a cross-sectional view of the main part, and Fig. 3 shows the main part. FIG. 4 is a front view shown in cross section, and FIG. 2 is (+iif).In the center of the upper surface of this traveling vehicle body 2, there is provided a driver's cab 4 in which a worker 3 rides and operates various devices, f, etc., which will be described later. A hydraulic power source 5, a prime mover 6 and its related equipment are installed (i1) to generate the specified hydraulic operating force and drive.

It is supplied to various devices and mechanisms that perform cutting, discharge, etc. The hydraulic pressure supplied from the oil Jk power source 5 is controlled by the operator 3 operating the hydraulic pressure controller 7 in the driver's cab 4 or by an automatic control mechanism or the like, and is controlled by various devices.

The mechanism is configured to actuate a hydraulically actuated portion of the mechanism.

There are whistles 2 and 3 on the front and rear of the left and right sides of the traveling vehicle body 2.
As shown in the figure, a total of four traveling devices 1 have the same structure.
i10 is installed. These traveling devices 10 are each independently driven up and down to travel on the ground, and the mounting position (installation height) is variable and set by being moved in a direction perpendicular to the plane of the vehicle body, that is, up and down. 11, and a running wheel 12 that runs on the ground surface except when excavating a trench.
It is made up of. To further explain these structures,
As shown in FIGS. 2 and 3M, the suspension device 11 has a slide leg 15 fitted to a guide block 14 fixed to a side plate 13 of the vehicle body so as to be slidable in the vertical direction. A leg vertical hydraulic motor 16 for driving the slide leg 15 is fixed. On the other hand, inside the guide block 14, there is a bevel gear 17 fixed to the shaft end of the hydraulic motor 16, and a passive bevel gear 19 meshing with the bevel gear 17 at right angles and screwed onto the threaded rod 18. The thrust of the passive bevel gear 19 is received by the inner bottom surface of the guide block 14. The screw frame 18 passes through the guide block 14, and the threaded frame 18 passes through the guide block 14, and T Ol,”,1
are fixedly held at the upper and lower ends of the slide leg 15. Therefore, the bevel gear 1 is driven by the hydraulic motor 16.
1 rotates and this! Passive water meshing with L +'1! ti car 1
When the gear 9 is rotated, the thrust of the gear 19 is received by the guide block 14, so the threaded rod 18 and the slide leg 15 that engage with the gear 19 slide vertically along the guide block 14. The height of the running wheels 12 is arbitrarily changed. This control is based on the direction of rotation of the 1 vomit motor 16.

This is done by adjusting the speed, and depending on the state of running land formation or excavation, each traveling device 10 can be adjusted individually, left and right or front and back simultaneously, or all traveling devices i:t10
By operating these simultaneously, the vehicle body 2 is held substantially horizontally. In this case, the expansion and contraction control of each suspension system 11 is controlled manually or automatically via a posture detector of the traveling vehicle body 2, etc. 7'L.

As shown in FIG. 3, the traveling j5 wheel 12 has a hub axle 20 fixed to the lower end of the sliding leg 15, and a hub 23 having a wheel drive hydraulic motor 22 built into the hub axle 20 and fixed thereto. are integrated. A wheel 26 is rotatably disposed on the outer periphery of the hub 23 via a bearing 25, and the hydraulic motor 220 is connected to the wheel 26.
The rotation is configured to be transmitted via a planetary gear mechanism 28. That is, the planetary gear mechanism 28 includes a sun gear 29 fixed to the output shaft 27 of the drive motor 22;
The sun gear 29 and three planetary gears 30 mesh with an internal gear 31 integrally provided on the inner circumferential wall of the wheel 26, respectively, and these planetary gears 30 are connected to the pin 30 of the hub Each is rotatably supported by a shaft.

A glove 35 that is in contact with the ground is provided on the outer peripheral surface of the wheel 26, while a well-known brake mechanism 3 is provided on the inside.
6 is included.

To drive the traveling vehicle body 2 forward and backward, the rotation of the drive motor 22 built in each traveling wheel 12 is controlled by a planetary gear mechanism 2.
8 and transmits the deceleration to the wheels 26, and turning to the left and right is performed by changing the rotational speed of the left and right running wheels 120, braking the inner wheels, etc. That is, the traveling wheels 12 of each traveling device 100 are controlled individually or in conjunction with each other, thereby enabling the traveling vehicle body 2 to move forward and backward and turn left and right.

Although a wheel type traveling device 10 is shown, the present invention is not limited to this, and it goes without saying that various types of traveling devices such as a crawler type traveling device may be used.

An excavating device 40 shown in FIGS. 1, 2, and 4 is disposed at the front of the traveling vehicle body 2 so as to be able to move up and down and rotate by a predetermined angle in the left and right directions. excavation is possible.

To explain the configuration of the excavation device 40 in more detail, as shown in FIG. 4, a pair of left and right arms 42a extend horizontally in the front-rear direction.
, 42b, and there are four holes between the tips of these arms 42a and 42b. A beam 41 is horizontally suspended, and at the center of the horizontal beam 41 is a vertical vertical beam 43 extending vertically.
The upper end of is fitted and fixed. A pair of chain sprockets 44a are provided at the upper and lower ends of the vertical beam 43, respectively.
, 44b, 45a, 45b (see FIGS. 1 and 2) are rotatably arranged. Further, one arm 4 of the pair of arms 42a and 42b
A hydraulic motor 47 (see FIG. 4) is disposed at the tip of 2a, and a chain sprocket 49 is fitted and fixed to the tip of its shaft 48. The tip of the shaft 48 is connected to the horizontal beam 4
It is pivotally supported by a bracket 55 fixed at the center of 1 and extending rearward. At the rear end of the bracket 55, a rotary shaft 53 having three chain sprockets 51, 52a, and 52b fixed thereto is rotatably arranged, and a driving link chain 56 is connected to the chain sprocket 49 of the shaft 48 and the chain sprocket 51. The bridge is completely crossed, and a pair of chain sprockets (52a, 52b) and the chain sprocket 44a of the vertical beam 43 mentioned above,
Link chains 59a and 59b (see FIG. 1) are also connected to 44b, 45a and 45b, respectively. Therefore, the link chains 59a, 59
The upper end of b protrudes rearward on the back side of the vertical beam 43 to form a substantially rectangular cavity 60 as shown in FIG.
is formed, and the horizontal beam 41 is inserted into this gap 60, and the bracket 55 can be attached thereto. On the other hand, the lower end of the excavation device 40, that is, the excavation operation θ1 section A, has the same cross-sectional shape and is approximately circular due to the cutter 2 described later, thereby making it possible to excavate curved grooves having approximately the same groove width as straight grooves. It makes it possible.

That is, the plurality of cutters 62 commonly attached to the pair of link chains 59a and 59b at a predetermined distance are formed into a flat plate shape and have a substantially D shape, as shown in FIGS. 2 and 4. This includes a linear front blade portion 62a and a pair of side blade portions 62b62c that are integrally connected to both ends of this blade portion 62a and are curved in an arc shape and extend rearward of the blade portion 62a. , the cutters 62 located front and rear with the longitudinal beam 43 in between have a substantially circular cross-sectional shape (see FIG. 2), and the link chain 59a,
By rotating and traveling together with 59b, the groove 64 is excavated, and at the same time, the excavated earth and sand is lifted up and guided to a discharger to be described later.

The link chains 59a and 59b are connected to the chain sprocket 52a through the rotation of the shaft 48 by the drive motor 47 through the link chain 56, chain sprocket 51, and rotating shaft 53.
, 52b, the vertical beam 43 is rotationally driven so as to rise on the front side and descend on the rear side. Further, the cutter 62 is not limited to a flat plate shape, and various modifications such as a chevron shape or a single cutter 62 that is divided and attached with offset in the height direction are possible.

Inside the pair of link chains 59a, 59b, as shown in FIGS. 1, 2, and 4, a plurality of small rollers 70 are rotatably disposed at predetermined intervals.
These small rollers TO are attached to a slide bracket T1 (see FIG. 1) fixed to the approximate center of the back surface of the vertical beam 43.
By rolling on the sliding surface of the link chain 5
9a and 59b are formed.

The rear ends of the seven pairs of left and right arms 42a and 42b are fixed to the door/door 3, and the mount 73 is fixed to a rotation block 74, as shown in FIGS. The rear end of the rotary block 74, ie, the vehicle body part 1, has a cylindrical shape and is rotatably installed in the center of the slide block 75.

A total of eight low shifters 6, each consisting of a pair of front and rear pairs, are rotatably attached to both ends of the upper and lower surfaces of the slide block 75, and these rollers 76 roll along the inner wall of the gate-shaped guide 17. 411・v is constructed as follows.

1) The IS record lock gate type ID 7T is the slide block 75.
It is attached almost perpendicularly to the front end of a poom 78 disposed on the upper surface of the front end of the traveling vehicle body 2. The pool 78 has a support l1Il111
9, it can freely move in the left and right directions in a horizontal plane, and this rotation is performed by a turning hydraulic cylinder 80 whose one end is connected to the traveling vehicle body 2. Note that 81 and 82 are rollers that are attached to the lower surface of the pool 78, respectively, and that come into contact with the upper surface of the front end portion of the traveling vehicle body 2 and the front end 1 [11].

The slide block T5, in other words, the excavation device 4
The vertical movement of 0 causes the wire 83, one end of which is fixed to the center of the upper surface of the block 15, to be wound up or unwound by the winding winch 84 attached to the upper part of the portal guide 77 via the shear sheave 85. The excavation depth of the groove 64 is thereby set arbitrarily. This excavation depth can be adjusted within a certain limit by changing the ground height H of the traveling vehicle body 2 (see Figure 1) by adjusting the lifting height f of the mower traveling in the trench, which will be described later. . Further, the excavation device 40 is rotated left and right in a horizontal plane by the rotation of the pool 78, and the rotation block 74
It is tilted left and right by zero rotation, and this tilting is performed by a hydraulic cylinder 88 whose one end is fixed to the rotating block 74 via a bracket 89 and the other end is connected to the slide block 75 via a bracket 90. .

A pair of front and rear groove traveling devices 95 and 96 are disposed at the lower part of the traveling vehicle body 2 on the longitudinal center line of the traveling vehicle body 2, and are in charge of running the traveling vehicle body 2 instead of the traveling device 10 during trench excavation. These pair of trench running devices i installed
ff 95 + 96 is disposed on the lower surface of the center frame 98, which is raised and lowered by a pair of front and rear pantograph lifting mechanisms 97A and 97B.

Here, since the pair of groove traveling devices 95, 96 and the lifting mechanisms 97A and 97B are constructed in the same manner, the groove traveling device 95 and the lifting mechanism 97A on the front side of the vehicle body are mainly illustrated in FIGS. 1 and 3. This will be explained in detail based on the figures.

First, the groove traveling device 95 includes a traveling wheel block 101 that is rotatable in a horizontal plane by having an upper end attached to the groove frame 98 via a bearing 100.
At the lower end of this block 101, the top part of a gear box 102, which has an inverted V shape when viewed from the side, is disposed so as to be able to freely swing ν1 via a shaft 103. A pair of left and right running wheels 104 are provided at the front and rear ends of the gear box 102, respectively.
a, 104b, 105a, 105b (105
b (not shown) is rotatably supported.
1. Grousers 106 are provided on the outer circumferential surface of the motor, and a well-known braking device is provided inside. A driving hydraulic motor 1 is mounted on the top side of the gear box 102.
07 is installed, and its rotation is controlled by gear train 10.
The running wheels 104a, 8A, 108B,
104b, 105a, 105b. Note that the wheel block 10
1 is rotated left and right by a hydraulic cylinder 109 shown in FIGS. 1 and 2, thereby making it possible to turn left and right when cutting groove 1;1. Note that one end of the hydraulic cylinder 109 is connected to the wheel block 101 via a bracket 110, and the other end is connected to the lower surface of the groove frame 98 via a bracket 111.

In this case, a wheel-type traveling device 95, 96 is shown, but the present invention is not limited to this, and it goes without saying that various traveling devices such as a crawler type can be used.

The elevating mechanism 97A includes a total of eight link members 116a, 116b, 116c, 11 interposed between the traveling vehicle body 2 and the groove frame 98, four on each side.
6d and 117a, 117b, 117c,
117d (116c and 116d are not shown), and is expanded and contracted by a total of two hydraulic cylinders 108A and 108B disposed at the left and right and front and rear center portions, and when the traveling device 10 is normally traveling. are folded so that the groove frame 98 and the groove traveling devices 95 and 96 are stored in the lower part of the traveling vehicle body 2.

Further, the front and rear elevating mechanisms 97A and 97B can be expanded and contracted independently, thereby making it possible to tilt the groove frame 98 back and forth with respect to the traveling vehicle body 2.

Further, a pair of left and right screw set earth removers 120 and 121 are disposed at the front of the traveling vehicle body 2 and located on both sides of the excavation device 400. These pair of earth removal machines 120,
121 are configured to be raised and lowered independently to accommodate excavation on steep slopes. In other words, the rear end of the earth removal screw 123 of the earth removal machine 120 is rotatably attached to the tip of a support arm 125 that is pivotally supported on one side of the portal guide 77 via a shaft 124 so as to be rotatable in the vertical direction. The support arm 125 is disposed on the side of the excavation device 40 and is configured to move up and down when the support arm 125 is rotated by a hydraulic cylinder 126. Similarly, the earth removing machine 121 on the left also has an earth removing screw 127 (see Figure 2).
and a support arm 128, and is raised and lowered by a hydraulic cylinder (not shown). and each support arm 125
, 128 are provided with hydraulic motors 130, 131, respectively, so that the rotation of these motors 130, 131 is transmitted to the earth removal screws 123, 127 via chains and chain sprockets, respectively. It is configured.

Therefore, the earth and sand excavated and lifted up by the excavation device 40 falls onto the earth removal screws i23 and 127 and is discharged to the outside of the earth removal machines 120 and 121.

Next, the operation of the trench excavator 1 having the above configuration will be explained.

First, when traveling on flat ground, the excavator 40. Ditch traveling device 95,96 and earth removal machine 120,
121 is pulled upward, and the left and right traveling devices 10 are extended by a required dimension to have the same height front and rear, left and right, and the vehicle travels while maintaining the ground clearance and horizontality of the traveling vehicle body 2 and the like.

When climbing up or down a slope, if the grade clearance and horizontal state of the vehicle body 2, etc. are maintained as in the case of running on flat ground, as shown in Figure 5(b), when climbing a steep slope, the front pair of running By retracting the device 10 and extending the pair of rear traveling devices 10 (reverse this in the case of adjacent vehicles), the traveling vehicle body 2
The level of the ground is maintained, preventing a decrease in effective ground contact pressure due to the cutting of the center of gravity G, and at the same time increasing the stability of the traveling vehicle body 20 and increasing the climbing ability.

When climbing a slope for a certain distance and moving across the slope, a pair of front and rear traveling devices 61 on the slope mountain side are used as shown in FIG. 5(c).
0 by a predetermined amount, and the pair of traveling devices 10 on the valley side are extended by a predetermined amount to move the center of gravity G of the traveling vehicle body 20 to the mountain side and maintain horizontality on the left and right sides. This increases the safety level and operability of the traveling vehicle body 2 and its occupants.

In addition, when turning in the running state shown in FIGS. 5(a), (b), and (c), it is necessary to change the driving speed of the left and right traveling devices 10, or to brake or reverse the driving speed of the left and right traveling devices 10. , it goes without saying that it can be turned in any desired direction.

Next, excavation on a steep slope is carried out in a state where the excavation is carried out across the slope as shown in FIG. 5(c). In this case, the traveling vehicle body 2 maintains the required ground clearance, and the excavating device 40° trench traveling device 9
5.96 and earth removal machines 120 and 121 in Fig. 5(d)
As the excavation device 40 is gradually lowered as shown in FIG. ,
The excavating device 4o descends together with the trench traveling device 95, 96 as it excavates to increase the excavation depth, but the required iA
After reaching the depth, by raising the traveling device 10, the running of the traveling vehicle body 2 itself is controlled by the groove traveling devices 19s, s.
Do it by a. FIG. 5(f) shows this state, and the deep grooves 64 are continuously cut. That is, during excavation, the traveling device 10 is lifted off the slope, and the trench traveling device 9 is lifted off the slope.
5.96 prevents the vehicle body 2 from skidding, etc.>.

The left and right earth removers 120 and 121 are set and held at different height positions so as not to touch the slope, and discharge the earth and sand excavated and scooped up by the cutter 62 outward, but when the ground surface is soft. If the soil removal screw 123 on the mountain side is actively driven into the ground surface and rotated, small-scale excavation can also be performed OT, and overhang around the trench can be prevented. 4)
1) The necessary pressing force against the excavation surface of the cutting device 40 is provided by the propulsion force of the traveling vehicle body 2.

1N; Since the pair of front and rear groove running devices 95 and 96 that are inserted into the groove 64 and run are individually rotated in the horizontal plane, stable running in the curved groove 140 shown in FIG. In this case, since the lower end of the excavation equipment fEZ40 has a substantially circular cross-sectional shape, it is possible to dig a curved groove with almost the same groove width as a straight groove, and the cutter 6
2. Prevent damage accidents, etc.

The groove traveling devices 95 and 96 include a swingable gear box 102 (see FIG. 1) and traveling wheels 104a.

Since 104b + 105a...11 are installed,
Even if foreign objects are exposed on the ocean floor, it can overcome them and will not interfere with forward movement.

As explained above, the trench excavator according to the present invention has a trench traveling device that can be raised and lowered at the lower part of the traveling vehicle body, and when excavating, 419 people move the trench traveling load into the trench along the bottom surface of the trench. 'Would you like to run?'f'i completed 7゛This eliminates the need to use a ground traveling device when excavating trenches by traversing a slope. Lateral drift of the axis can be reliably prevented, and trench excavation on steep slopes can be performed stably and reliably.

In addition, since the ground running devices installed on both sides of the vehicle body to support the vehicle body can be raised and lowered independently, it is easy to maintain the vehicle body horizontally when traversing a slope, resulting in excellent maneuverability and safety. ing. In addition, since this traveling device is mounted vertically and its lifting height changes, the traveling vehicle body does not move back and forth due to the mounting height, and changes in slopes and ground surfaces continue, resulting in To enable smooth running even when the mounting height of each traveling device is changed.

Furthermore, since the excavation equipment and trench traveling equipment fh5 are arranged so that they can be raised and lowered and rotated in a horizontal plane, they can be moved directly.
I! Not just the grooves, but the songs! ! Grooves, folded grooves.

Any desired trench, such as a zigzag trench, can be excavated continuously without interruption in various terrains. In addition, the trench excavator has a ground running device and a trench running device, allowing it to travel on its own blade and traverse slopes, and during continuous trench excavation, it can be used in rocky or wooded areas that are difficult to excavate or detour around.

Even if you encounter a stream or a mountain road, by switching between the two traveling devices, you can easily and safely get over it without falling over or skidding, and then resume excavation. is very large and versatile.

[Brief explanation of the drawing]

Fig. 1 is a partially omitted side sectional view showing an embodiment of the trench excavator according to the present invention in an excavating state, Fig. 2 is a cross-sectional view of the main part, and Fig. 3 is a front view showing the main part in cross section. 4 is a sectional view taken along the line TV-N in FIG. 1, and FIG. 5 is a diagram for explaining the running and digging operation of the trench excavator, in which (a) is running on flat ground, (b)
4C) is the state of traversing the slope, (d) is the state of starting trench excavation, (e) is the state immediately after starting trench excavation, and (f) is the state of traversing.
) is a diagram showing the state of deep trench excavation, and FIG. 6 is a diagram showing the state of curved trench digging. 1. Meeting... trench excavator, 2-... traveling vehicle body, 1°...
・Running gear fi? , 40...excavation, 62...0...
Cutter, 64...Groove, 95,960...Groove traveling device. Patent applicant Ube Industries Co., Ltd. agent Kazubin Yamakawa (1 person) (C) (e) Soko, So0 Figure 5 (d)

Claims (2)

[Claims] (1) A traveling vehicle body, a plurality of traveling devices that are respectively disposed on both sides of the traveling vehicle body and run on the ground, and that are independently raised and lowered to hold the traveling vehicle body horizontally; The excavation device is provided with an excavation device that is freely disposed to excavate a trench, and a trench traveling device that is disposed under the traveling vehicle body so as to be freely raised and lowered, and that is inserted into the trench and runs on the bottom surface of the trench when excavating the trench. A trench excavator characterized by: (2) a traveling vehicle body, a plurality of traveling devices that are respectively disposed on both sides of the traveling vehicle body, travel on the ground, and hold the traveling vehicle horizontally by being raised and lowered independently; An excavation device that is disposed freely and rotatably in a horizontal plane to excavate a trench; A trench excavator characterized by comprising a trench traveling device that is inserted and runs by itself on the bottom surface of the trench.