A three-dimensional displacement monitoring structure inside a mine

Abstract

The present invention relates to the field of mine monitoring technology, specifically a three-dimensional displacement monitoring structure inside a mine, comprising a mounting frame for support, a walking crawler for movement is arranged at the bottom of the mounting frame, a horizontal propeller for horizontal propulsion and a vertical propeller for vertical propulsion are arranged above the mounting frame, a mounting platform is arranged on the upper surface of the mounting frame, a survey component is arranged on the upper surface of the mounting platform, and the survey component includes a mounting cover, the mounting cover is fixedly connected to the middle of the upper surface of the mounting platform, and a sampling tube is arranged in the middle of the mounting cover. Multiple spaces are separated by a bottom spacer in the sampling tube, so that water at different positions can be stored. When sampling water enters one of the spaces, the internal liquid level rises, and the buoyancy ring arranged inside moves upward under the action of buoyancy until the buoyancy ring blocks the sampling hole, and the sampling hole can be sealed by the side wall of the buoyancy ring.

Description

Technical Field

[0001] The invention relates to the technical field of mine monitoring, in particular to a three-dimensional displacement monitoring structure inside a mine. Background Art

[0002] There are many water sources in mines, and the water contains a large amount of suspended matter such as rock particles, which leads to turbid water quality, poor color, and poor sensory properties. These suspended matter will also increase the chemical oxygen demand, promote bacterial growth, and pollute the environment when discharged. The flowing water inside the mine may be corrosive. The salt content of mine water is generally 1000-3000 mg / L, containing a variety of ions such as calcium ions, magnesium ions, sodium ions, potassium ions, sulfate ions, bicarbonate ions, chloride ions, fluoride ions, etc., resulting in high water hardness. High mineralization and hardness are corrosive to equipment and affect the strength of underground concrete and wooden structures.

[0003] When monitoring a mine, the water flowing inside may affect the displacement inside the mine. Due to the complex internal structure of the mine, the staff needs to survey the inside of the mine, sample the rocks and water inside, and monitor the inside of the mine through monitoring equipment, which is conducive to ensuring the safety of subsequent resource mining. Due to the complex structure inside the mine and the difficulty in determining the depth of the water level in the mine, it is cumbersome for the staff to take samples, and it is troublesome to monitor the water level in the mine cave, and there are certain safety risks. In view of the above problems, the present invention proposes a three-dimensional displacement monitoring structure inside the mine. Summary of the invention

[0004] In view of the problems in the prior art, the present invention provides a three-dimensional displacement monitoring structure inside a mine.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a three-dimensional displacement monitoring structure inside a mine, comprising a mounting frame for support, a walking crawler for movement is arranged at the bottom of the mounting frame, a horizontal thruster for horizontal pushing and a vertical thruster for vertical pushing are arranged above the mounting frame, and a mounting platform is arranged on the upper surface of the mounting frame; a survey component, the survey component is arranged on the upper surface of the mounting platform, and the survey component includes a mounting cover, the mounting cover is fixedly connected to the middle part of the upper surface of the mounting platform, a sampling tube is arranged in the middle part of the mounting cover, the sampling tube slides through the mounting platform, a sampling hole is opened on the outer wall of the sampling tube, and the sampling tube is made of transparent material; a plurality of bottom spacers are arranged on the inner wall of the sampling tube, the bottom spacers are thick at the edges and thin in the middle, and the bottom spacers are made of elastic material.

[0006] Specifically, the bottom spacer is made of anti-corrosion and waterproof material, and the thickness of the middle part of the bottom spacer is between 0.6mm and 1mm, and the thickness of the edge of the bottom spacer is between 2mm and 4mm.

[0007] Specifically, a buoyancy ring is arranged in the sampling tube, a pull rope is arranged at the bottom of the buoyancy ring, the diameter of the pull rope is a 0.8mm-1mm fiber line, and one end of the pull rope away from the buoyancy ring is fixedly connected to the middle of the bottom spacer.

[0008] Specifically, a hanger protrusion is integrally formed on the outer wall of the top of the buoyancy ring, a limiting protrusion is fixedly provided on the inner wall of the sampling tube, the limiting protrusion is placed above the corresponding sampling hole, and the hanger protrusion and the limiting protrusion are matched.

[0009] Specifically, a storage cover is fixedly arranged at the bottom of the mounting frame, and the lower end of the sampling tube is slidably inserted in the storage cover, and the storage cover seals the sampling hole inside.

[0010] Specifically, a driving motor is fixedly connected to the outer wall of one side of the mounting cover, and the output end of the driving motor rotates and penetrates the outer wall of the mounting cover. A driving gear and a driven gear are rotatably arranged on the inner wall of the mounting cover. The driving gear is fixedly connected to the output end of the driving motor, and the driving gear is meshed with the driven gear. The same side of the driving gear and the driven gear is connected to a first belt pulley through a connecting shaft.

[0011] Specifically, outer control wheels are provided on both sides of the sampling tube, the outer walls of the outer control wheels are roughly provided, rotating shafts are fixedly connected on both sides of the outer control wheels, a sliding block is rotatably provided on one end of the rotating shaft away from the outer control wheel, a sliding groove is provided on the inner wall of the mounting cover, and the sliding block is slidably inserted in the sliding groove.

[0012] Specifically, an electric control push rod is fixedly connected to the end of the inner wall of the sliding groove, and the telescopic end of the electric control push rod is fixedly connected to the sliding block.

[0013] Specifically, a plurality of cylinders are fixedly connected to the outer wall of the rotating shaft, and an arcuate belt pulley is fixedly connected to the telescopic end of the cylinder, a gap is left between two adjacent arcuate belt pulleys, and the arcuate belt pulley is connected to the first belt pulley through a transmission belt.

[0014] Specifically, the upper surface of the mounting frame is fixedly connected with a fixing frame, the middle part of the fixing frame is fixedly connected with a surveyor cover, a transparent cover body is arranged at the front end of the surveyor cover, and a surveyor is installed in the surveyor cover.

[0015] Beneficial effects of the present invention:

[0016] The three-dimensional displacement monitoring structure inside a mine described in the present invention is different from the prior art in that the present application separates multiple spaces through a bottom partition in a sampling tube, thereby being able to store water at different positions. When the sampled water enters one of the spaces, the internal liquid level rises, and the buoyancy ring arranged inside moves upward under the action of buoyancy until the buoyancy ring blocks the sampling hole. When too much water enters, the protrusion of the hanger moves to the top of the limit protrusion for engagement, and the sampling hole can be sealed through the side wall of the buoyancy ring. During the rising process of the buoyancy ring, the middle part of the bottom partition at the bottom is pulled upward by a pull rope, thereby generating negative pressure in the space below. When the buoyancy ring is moved out of the storage cover for liquid collection, the entry of water can be accelerated. At the same time, the bottom of the buoyancy ring is placed in water in the space filled with water by the setting of the pull rope, which can ensure the stability of the buoyancy it is subjected to. Multiple pull ropes are symmetrically arranged to ensure the stability of the buoyancy ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 It is a schematic diagram of the three-dimensional structure of the surveyor cover of the present invention;

[0020] Figure 3 It is a schematic diagram of the three-dimensional structure of the surveying device of the present invention;

[0021] Figure 4 It is the installation cover and sampling tube position diagram of the present invention;

[0022] Figure 5 This is a three-dimensional diagram of the sleeve connection between the storage cover and the sampling tube of the present invention;

[0023] Figure 6 A partial cross-sectional view of the sampling tube of the present invention;

[0024] Figure 7 For the present invention Figure 6 Schematic diagram of the structure at B in the middle;

[0025] Figure 8 For the present invention Figure 6 Schematic diagram of the structure at A in the middle;

[0026] Fig. 9 It is a schematic diagram of the three-dimensional structure of the outer control wheel of the present invention.

[0027] In the figure: 1. walking track; 2. mounting frame; 21. mounting platform; 3. horizontal thruster; 31. vertical thruster; 32. surveyor cover; 33. surveyor; 34. fixing frame; 6. surveying assembly; 61. mounting cover; 62. driving motor; 63. sampling tube; 631. sampling hole; 632. buoyancy ring; 6321. bracket protrusion; 633. bottom spacer; 634. pull rope; 636. limiting protrusion; 64. storage cover; 65. driving gear; 66. driven gear; 67. first belt pulley; 68. rotating shaft; 681. cylinder; 682. arc belt pulley; 683. transmission belt; 684. electric control push rod; 685. sliding block; 69. external control wheel. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0029] Embodiment 1:

[0030] like Figure 1-Figure 9 As shown, a three-dimensional displacement monitoring structure inside a mine of the present invention comprises a mounting frame 2 for support, a walking crawler 1 for movement is arranged at the bottom of the mounting frame 2, a horizontal propeller 3 for horizontal pushing and a vertical propeller 31 for vertical pushing are arranged above the mounting frame 2, and a mounting platform 21 is arranged on the upper surface of the mounting frame 2; a survey component 6, the survey component 6 is arranged on the upper surface of the mounting platform 21, and the survey component 6 comprises a mounting cover 61, the mounting cover 61 is fixedly connected to the middle part of the upper surface of the mounting platform 21, a sampling tube 63 is arranged in the middle part of the mounting cover 61, the sampling tube 63 slides through the mounting platform 21, a sampling hole 631 is opened on the outer wall of the sampling tube 63, and the sampling tube 63 is made of transparent material; a plurality of bottom spacers 633 are arranged on the inner wall of the sampling tube 63, the bottom spacers 633 are thick at the edges and thin in the middle, and the bottom spacers 633 are made of elastic material.

[0031] The mounting frame 2 can support and install various components, wherein the walking track 1 can be adapted to more complex environments and can also walk underwater. The horizontal propeller 3 can control its movement in the water and the vertical propeller 31 can control its up and down movement in the water, which is convenient for sampling water at different depths in deep pits in mines. The survey component 6 can be used to sample water at different depths in the mine, and the sampling tube 63 can be used to store water. The sampling tube 63 is made of transparent material, which can facilitate observation of the internal water height and ensure sufficient survey samples when sampling.

[0032] Specifically, the bottom spacer 633 is made of anti-corrosion and waterproof material, and the thickness of the middle part of the bottom spacer 633 is between 0.6 mm and 1 mm, and the thickness of the edge of the bottom spacer 633 is between 2 mm and 4 mm.

[0033] The bottom spacer 633 will come into contact with the water in the mine, which may be highly corrosive. The bottom spacer 633 is an anti-corrosion and waterproof material that can separate the space and ensure its service life. The middle part of the bottom spacer 633 has a thickness of 0.6mm-1mm and can be deformed under the action of tension. It can also save materials and make the entire sampling tube 63 lighter.

[0034] Specifically, a buoyancy ring 632 is provided in the sampling tube 63 , a pull rope 634 is provided at the bottom of the buoyancy ring 632 , the pull rope 634 has a diameter of 0.8mm-1mm fiber line, and one end of the pull rope 634 away from the buoyancy ring 632 is fixedly connected to the middle of the bottom spacer 633 .

[0035] Specifically, the top outer wall of the buoyancy ring 632 is integrally formed with a hanger protrusion 6321, the inner wall of the sampling tube 63 is fixedly provided with a limiting protrusion 636, the limiting protrusion 636 is placed above the corresponding sampling hole 631, and the hanger protrusion 6321 and the limiting protrusion 636 are arranged in coordination.

[0036] Specifically, a storage cover 64 is fixedly provided at the bottom of the mounting frame 2 , and the lower end of the sampling tube 63 is slidably inserted in the storage cover 64 , and the storage cover 64 is opposite to the internal sampling hole 631 and sealed.

[0037] The sampling tube 63 is separated into multiple spaces by a bottom spacer 633, so that water at different positions can be stored. When the sampled water enters one of the spaces, the internal liquid level rises, and the buoyancy ring 632 arranged inside moves upward under the action of buoyancy until the buoyancy ring 632 blocks the sampling hole 631. When too much water enters, the bracket protrusion 6321 moves to the top of the limit protrusion 636 for engagement, and the sampling hole 631 can be sealed through the side wall of the buoyancy ring 632.

[0038] During the rising process of the buoyancy ring 632, the middle part of the bottom partition 633 will be pulled upward through the pull rope 634, so that negative pressure is generated in the space below. When it moves out of the storage cover 64 to collect liquid, the entry of water can be accelerated. At the same time, the bottom of the buoyancy ring 632 is placed in the water by setting the pull rope 634 in the water-filled space, which can ensure the stability of the buoyancy it receives. Multiple pull ropes 634 are symmetrically arranged to ensure the stability of the buoyancy ring 632.

[0039] The storage cover 64 serves to store the sampling tube 63. The sampling tube 63 placed in the storage cover 64 is in a sealed state and no water can enter. When the sampling tube 63 moves upward from the storage cover 64, water will enter the space inside the sampling tube 63 through the corresponding sampling hole 631 for storage.

[0040] Embodiment 2:

[0041] It is basically the same as the first embodiment. Figure 1 , Figure 4-Figure 9 As shown, the difference is that a driving motor 62 is fixedly connected to the outer wall of one side of the mounting cover 61, and the output end of the driving motor 62 rotates and penetrates the outer wall of the mounting cover 61, and a driving gear 65 and a driven gear 66 are rotatably provided on the inner wall of the mounting cover 61, and the driving gear 65 is fixedly connected to the output end of the driving motor 62, and the driving gear 65 is meshed with the driven gear 66, and the same side of the driving gear 65 and the driven gear 66 are connected to a first belt pulley 67 through a connecting shaft.

[0042] The sampling tube 63 is provided with an outer control wheel 69 on both sides, and the outer wall of the outer control wheel 69 is rough. The outer control wheel 69 is fixedly connected with a rotating shaft 68 on both sides. The end of the rotating shaft 68 away from the outer control wheel 69 is rotatably provided with a sliding block 685. The inner wall of the mounting cover 61 is provided with a sliding groove, and the sliding block 685 is slidably inserted in the sliding groove. An electric control push rod 684 is fixedly connected to the end of the inner wall of the sliding groove, and the telescopic end of the electric control push rod 684 is fixedly connected to the sliding block 685. A plurality of cylinders 681 are fixedly connected to the outer wall of the rotating shaft 68, and an arc belt pulley 682 is fixedly connected to the telescopic end of the cylinder 681. A gap is left between two adjacent arc belt pulleys 682, and the arc belt pulley 682 is connected to the first belt pulley 67 through a transmission belt 683.

[0043] The output end of the driving motor 62 drives the driving gear 65 placed in the mounting cover 61 to rotate during the rotation process. When the driving gear 65 rotates, it also drives the meshing driven gear 66 to rotate. The driving gear 65 and the driven gear 66 synchronously drive the first belt pulley 67 connected to one side to rotate. The first belt pulley 67 drives the rotating shaft 68 to rotate during the rotation process. The rotating shaft 68 drives the outer control wheel 69 to rotate during the rotation process. The two outer control wheels 69 can drive the sampling tube 63 in contact in the middle to move upward during the rotation process. Water enters the sampling tube 63 through the sampling hole 631 set on one side of the sampling tube 63 for storage. The sampling tube 63 is clamped by the outer control wheel 69 to ensure that it can be more stable at the bottom of the water.

[0044] There is a gap between the arc-shaped belt pulleys 682. When the belt is compressed, the telescopic end of the cylinder 681 will be shortened, the gap between the arc-shaped belt pulleys 682 will be reduced, and the distance between the two outer control wheels 69 can be changed.

[0045] Embodiment three:

[0046] It is basically the same as the first embodiment. Figure 1-Figure 3 As shown, the difference is that a fixing frame 34 is fixedly connected to the upper surface of the mounting frame 2, a surveyor cover 32 is fixedly connected to the middle of the fixing frame 34, a transparent cover body is provided at the front end of the surveyor cover 32, and a surveyor 33 is installed in the surveyor cover 32.

[0047] The internal environment of the mine can be collected through the surveyor 33, and the surveyor cover 32 can provide protection for the surveyor 33. At the same time, the surveyor cover 32 is a convex lens, which can provide a wider viewing angle for the surveyor 33. When conducting underwater surveys, the liquid level in the sampling tube 63 can be observed, and the surrounding environment can also be observed. When it is observed that the corresponding space of the sampling tube 63 is full of water, sampling can be controlled to another area.

[0048] Working principle: When it is necessary to monitor the inside of the mine, the walking track 1 can adapt to various road conditions through remote control, the internal environment of the mine can be collected through the surveyor 33, and the surveyor cover 32 can provide protection for the surveyor 33. At the same time, the surveyor cover 32 is a convex lens, which can provide a wider viewing angle for the surveyor 33.

[0049] When encountering a pool or a deep water area in a mine, the walking track 1 can be used to directly enter the water, and the air cylinder can prevent water from entering the surveyor 33 through the surveyor cover 32. After entering the water, the horizontal propeller 3 can be used to control the movement in the water. When water sampling is required during the movement, the sampling tube 63 is driven by controlling the drive motor 62 to move for sampling, which is convenient for the subsequent analysis of the water in the mine.

[0050] The output end of the driving motor 62 drives the driving gear 65 placed in the mounting cover 61 to rotate during the rotation process. When the driving gear 65 rotates, it also drives the meshing driven gear 66 to rotate. The driving gear 65 and the driven gear 66 synchronously drive the first belt pulley 67 connected to one side to rotate. The first belt pulley 67 drives the rotating shaft 68 to rotate during the rotation process. The rotating shaft 68 drives the outer control wheel 69 to rotate during the rotation process. The two outer control wheels 69 can drive the sampling tube 63 in contact in the middle to move upward during the rotation process. Water enters the sampling tube 63 through the sampling hole 631 set on one side of the sampling tube 63 for storage. The sampling tube 63 is clamped by the outer control wheel 69 to ensure that it can be more stable at the bottom of the water.

[0051] The sampling tube 63 is separated into multiple spaces by a bottom spacer 633, so that water at different positions can be stored. When the sampled water enters one of the spaces, the internal liquid level rises, and the buoyancy ring 632 arranged inside moves upward under the action of buoyancy until the buoyancy ring 632 blocks the sampling hole 631. When too much water enters, the bracket protrusion 6321 moves to the top of the limit protrusion 636 for engagement, and the sampling hole 631 can be sealed through the side wall of the buoyancy ring 632.

[0052] During the rising process of the buoyancy ring 632, the middle part of the bottom partition 633 will be pulled upward through the pull rope 634, so that negative pressure is generated in the space below. When it moves out of the storage cover 64 to collect liquid, the entry of water can be accelerated. At the same time, the bottom of the buoyancy ring 632 is placed in the water by setting the pull rope 634 in the water-filled space, which can ensure the stability of the buoyancy it receives. Multiple pull ropes 634 are symmetrically arranged to ensure the stability of the buoyancy ring 632.

[0053] When the sampling tube 63 needs to be taken out, the telescopic end of the electric control push rod 684 is controlled to shorten. When the telescopic end of the electric control push rod 684 shortens, the sliding block 685 pulls the rotating shaft 68 to move away from the first belt pulley 67. At this time, the cylinder 681 will be pressurized by the transmission belt 683, the telescopic end of the cylinder 681 will shrink, and the two outer control wheels 69 will move away from each other, so that the sampling tube 63 can be taken out easily.

[0054] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A three-dimensional displacement monitoring structure inside a mine, characterized by: It comprises a mounting frame (2) for supporting, a walking crawler (1) for moving is arranged at the bottom of the mounting frame (2), a horizontal propeller (3) for horizontal propulsion and a vertical propeller (31) for vertical propulsion are arranged above the mounting frame (2), and a mounting platform (21) is arranged on the upper surface of the mounting frame (2); A survey component (6), the survey component (6) being arranged on the upper surface of the mounting platform (21), and the survey component (6) comprising a mounting cover (61), the mounting cover (61) being fixedly connected to the middle part of the upper surface of the mounting platform (21), a sampling tube (63) being arranged in the middle part of the mounting cover (61), the sampling tube (63) slidingly passing through the mounting platform (21), a sampling hole (631) being arranged on the outer wall of the sampling tube (63), and the sampling tube (63) being made of a transparent material; The inner wall of the sampling tube (63) is provided with a plurality of bottom spacers (633), the bottom spacers (633) are thick at the edges and thin in the middle, and the bottom spacers (633) are made of elastic material; A buoyancy ring (632) is arranged in the sampling tube (63), a pull rope (634) is arranged at the bottom of the buoyancy ring (632), and one end of the pull rope (634) away from the buoyancy ring (632) is fixedly connected to the middle of the bottom spacer (633); The top outer wall of the buoyancy ring (632) is integrally formed with a hanger protrusion (6321), the inner wall of the sampling tube (63) is fixedly provided with a limit protrusion (636), the limit protrusion (636) is placed above the corresponding injection hole (631), and the hanger protrusion (6321) and the limit protrusion (636) are arranged in coordination; The sampling tube (63) is divided into a plurality of spaces by a bottom spacer (633), and water at different positions can be stored. When sampling water enters one of the spaces, the internal liquid level rises, and the buoyancy ring (632) arranged inside moves upward under the action of buoyancy until the buoyancy ring (632) blocks the sampling hole (631). When too much water enters, the bracket protrusion (6321) moves to the top of the limit protrusion (636) to engage, and the sampling hole (631) is sealed through the side wall of the buoyancy ring (632).

2. A three-dimensional displacement monitoring structure inside a mine according to claim 1, characterized in that: The bottom spacer (633) is made of an anti-corrosion and waterproof material, and the thickness of the middle portion of the bottom spacer (633) is between 0.6 mm and 1 mm, and the thickness of the edge of the bottom spacer (633) is between 2 mm and 4 mm.

3. A three-dimensional displacement monitoring structure inside a mine according to claim 2, characterized in that: The pull rope (634) has a diameter of 0.8 mm to 1 mm fiber wire.

4. The three-dimensional displacement monitoring structure inside a mine according to claim 1, characterized in that: A storage cover (64) is fixedly provided at the bottom of the mounting frame (2), and the lower end of the sampling tube (63) is slidably inserted into the storage cover (64), and the storage cover (64) is sealed against the sampling hole (631) inside.

5. A three-dimensional displacement monitoring structure inside a mine according to claim 4, characterized in that: A driving motor (62) is fixedly connected to an outer wall of one side of the mounting cover (61); an output end of the driving motor (62) rotatably penetrates the outer wall of the mounting cover (61); a driving gear (65) and a driven gear (66) are rotatably provided on an inner wall of the mounting cover (61); the driving gear (65) is fixedly connected to the output end of the driving motor (62); the driving gear (65) and the driven gear (66) are meshedly provided; and a first belt pulley (67) is connected to the same side of the driving gear (65) and the driven gear (66) via a connecting shaft.

6. A three-dimensional displacement monitoring structure inside a mine according to claim 5, characterized in that: External control wheels (69) are provided on both sides of the sampling tube (63), the outer wall of the external control wheel (69) is roughly provided, and rotating shafts (68) are fixedly connected to both sides of the external control wheel (69), and a sliding block (685) is rotatably provided at one end of the rotating shaft (68) away from the external control wheel (69), and a sliding groove is provided on the inner wall of the mounting cover (61), and the sliding block (685) is slidably inserted in the sliding groove.

7. A three-dimensional displacement monitoring structure inside a mine according to claim 6, characterized in that: An electric control push rod (684) is fixedly connected to the end of the inner wall of the sliding groove, and the telescopic end of the electric control push rod (684) is fixedly connected to the sliding block (685).

8. The three-dimensional displacement monitoring structure inside a mine according to claim 6, characterized in that: A plurality of cylinders (681) are fixedly connected to the outer wall of the rotating shaft (68); a telescopic end of the cylinder (681) is fixedly connected to an arcuate belt pulley (682); a gap is left between two adjacent arcuate belt pulleys (682); and the arcuate belt pulley (682) is connected to the first belt pulley (67) via a transmission belt (683).

9. The three-dimensional displacement monitoring structure inside a mine according to claim 1, characterized in that: A fixing frame (34) is fixedly connected to the upper surface of the mounting frame (2), a surveyor cover (32) is fixedly connected to the middle of the fixing frame (34), a transparent cover body is provided at the front end of the surveyor cover (32), and a surveyor (33) is installed in the surveyor cover (32).

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