Coil framework device in tunnel overlapped small loop transient electromagnetic method

Abstract

The invention belongs to the technical field of induction detection equipment, and provides an in-tunnel overlapped small loop transient electromagnetic method coil framework device which comprises eight framework units which are sequentially connected end to end, each framework unit comprises a rod body, an end universal joint and a transition universal joint, a horn-shaped apron board is arranged at the position, close to the end of the rod body, of the rod body, and the transition universal joint is connected with the end universal joint. The apron board is provided with a through hole used for wiring, and the outer sides of the adjacent framework units are provided with shaping units with C-shaped clamping holes. The eight framework units connected in sequence can be synchronously unfolded and synchronously contracted, the framework units and the shaping units in the contracted state are convenient to carry, the framework units and the shaping units in the unfolded state can be matched to form a relatively stable square framework system, and the sensing signal precision can be guaranteed; and the apron boards on the rod body provide constraint nodes for winding of the coil on the square framework system, adhesive tape connection is avoided, the stability is high, the tunnel site building time is saved, and the device is suitable for large-scale popularization.

Description

Technical Field

[0001] The present invention belongs to the technical field of induction detection equipment, and particularly relates to a coil skeleton device for the overlapping small-loop transient electromagnetic method in a tunnel. Background Technique

[0002] The theoretical basis of the transient electromagnetic method is the law of electromagnetic induction. By supplying a bipolar pulse current through an ungrounded loop or a grounded long wire, when the steady current in the loop is suddenly cut off, the sudden change in the current in the transmitting loop will generate a primary magnetic field around it. During the propagation of the primary magnetic field, if it encounters a good-conducting geological body underground, an induced current, i.e., eddy current or secondary current, will be excited inside it. Due to the non-linearity of the conducting geological body, after the primary magnetic field disappears, the eddy current does not disappear immediately but has a transient process, and its speed is related to the electrical parameters, volume scale, burial depth of the conductor, and the shape and frequency of the transmitting current. This transient process of the eddy current will form a corresponding transient magnetic field in space, i.e., the secondary magnetic field. By measuring the spatial distribution pattern of the secondary field with a receiving coil, the existence of abnormal geological bodies underground can be found, and the electrical structure and spatial distribution pattern of the abnormal bodies can be determined.

[0003] For geophysical prospecting operations in a tunnel, the transient electromagnetic method is also adopted. During this operation, the transmitting loop used requires a special coil frame structure. Since the transient electromagnetic method of the multi-turn small-loop device needs to ensure the quality of data acquisition, it is required that the multi-turn loop be arranged as square or circular as possible during construction. When constructing in a tunnel, it is required to place the loop device vertically, and at this time, the coil needs to be placed in a frame with a fixed shape to ensure that its shape meets the requirements. The currently commonly used method is to use materials such as PVC pipes, tees, and straight joints to install a square frame underground, and then bind the coil to the PVC pipes with tape. The problems existing in this way of building the skeleton are that, considering the requirements of the wire frame specifications, 8 1m-long PVC pipes and multiple PVC joints need to be carried, the on-site construction time is long, and it is not convenient to carry; furthermore, due to material problems, after more than 3 times, the joints of the PVC pipes will break and become loose, resulting in the frame being unable to maintain a regular square shape, affecting the accuracy of data signals; secondly, the on-site built skeleton has poor stability and support, and requires multiple people to hold and fix it. Summary of the Invention

[0004] In view of the above technical problems existing in the on-site built skeleton in a tunnel, the present invention provides a coil skeleton device for the overlapping small-loop transient electromagnetic method in a tunnel, which has reasonable design, good portability, high stability, can save the on-site construction time in the tunnel, and is beneficial to ensuring the accuracy of induction signals.

[0005] To achieve the above object, the technical solution adopted by the present invention is that a coil skeleton device for the overlapping small-loop transient electromagnetic method in a tunnel provided by the present invention includes 8 skeleton units. The skeleton units are made of non-metallic materials, and the 8 skeleton units are connected end to end in sequence. The skeleton unit includes a rod body, and end universal joints are provided at both ends of the rod body. A transition universal joint hinged thereto is provided at the end of one of the end universal joints. The transition universal joint is used to connect adjacent skeleton units. A trumpet-shaped skirt plate is provided at a position near the end of the rod body. A plurality of through holes distributed in a circular array are provided on the skirt plate, and the through holes are used for wire routing. A shaping unit is provided on the outer side of adjacent skeleton units. The shaping unit is used to shape the skeleton units into a square. The shaping unit is made of non-metallic materials. The shaping unit includes C-shaped card holes provided at both ends thereof for quick clamping with the rod body.

[0006] Preferably, the shaping unit includes an arcuate section, the thickness of the arcuate section gradually thins from the middle to both ends thereof, shovel-shaped sections are provided at both ends of the arcuate section, the width of the shovel-shaped sections is greater than the width of the arcuate section, and the C-shaped card holes are provided at the ends of the shovel-shaped sections.

[0007] Preferably, an arc-shaped opening is provided in the middle of the arcuate section.

[0008] Preferably, a support member matching with the arcuate section and the arc-shaped opening is provided on the shaping unit. The support member has an R-shaped structure and includes a vertical section. An S-shaped arc section is provided at the top of the vertical section, and the end of the S-shaped arc section bends and extends towards the end of the vertical section.

[0009] Preferably, at least 1 reinforcement component is provided on the rod body. The reinforcement component includes a left sleeve buckle and a right sleeve buckle that are relatively clamped and matched. The left sleeve buckle is a semi-cylindrical structure with a pair of arc-shaped buckle grooves provided at both ends thereof. The right sleeve buckle is a semi-cylindrical structure with a pair of buckle teeth provided at both ends thereof for clamping with the buckle grooves. The cross-section where the buckle teeth are located is C-shaped.

[0010] Preferably, a pair of key-shaped positioning grooves are provided on the surface of the left sleeve buckle opposite to the right sleeve buckle, and a pair of key-shaped positioning protrusions are provided on the surface of the right sleeve buckle opposite to the left sleeve buckle.

[0011] Preferably, two pairs of countersunk holes are provided on both the left sleeve buckle and the right sleeve buckle. The countersunk holes on the left sleeve buckle and the right sleeve buckle are connected by 4 symmetrically arranged lock rings in pairs. The lock ring includes an M-shaped section, and a pair of straight sections opposite to the M-shaped opening are provided at both ends of the M-shaped section. A tenon head is provided at the end of the straight section. The M-shaped section can be flipped around the cooperation center of the tenon head and the countersunk hole to the end faces of the left sleeve buckle and the right sleeve buckle.

[0012] Preferably, the end universal joint is threadedly connected to a threaded sleeve disposed in a sink groove at the end of the rod body. An inner shoulder is provided on the inner wall of the threaded sleeve. An axially limiting core is provided inside the threaded sleeve and is axially limited and cooperated with the inner shoulder of the threaded sleeve. A T-shaped sleeve is provided at the end of the threaded sleeve. A plurality of first annular grooves are provided on the inner wall of the T-shaped sleeve. A plurality of second annular grooves are provided on the outer wall of the axially limiting core. A snap ring is provided in the corresponding first annular groove and second annular groove. The T-shaped sleeve is provided with an end hinge head at the end facing away from the threaded sleeve.

[0013] Preferably, the transition universal joint includes a first transition hinge head hinged to the end hinge head. At least two axially spaced third annular grooves are provided on the side of the first transition hinge head. A second transition hinge head is nested on the first transition hinge head. A plurality of radial screws are provided on the outer side of the nested surface of the second transition hinge head and the first transition hinge head. The end of the radial screw is in sliding contact with the groove surface of the third annular groove.

[0014] Preferably, the rod body includes a rod head and a solid rod body. The diameter of the rod body is smaller than the diameter of the rod head. The skirt plate is provided at the position where the rod head and the rod body are connected, and its flared opening faces the middle direction of the rod body.

[0015] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0016] A coil skeleton device for the overlapping small loop transient electromagnetic method in a tunnel provided by the present invention can be synchronously deployed and synchronously contracted through 8 successively connected skeleton units. The skeleton units and the shaping units in the contracted state are convenient to carry, and the skeleton units in the deployed state cooperate with the shaping units to form a relatively stable square skeleton system, which is beneficial to ensuring the accuracy of induction signals; the skirt plate on the rod body provides a constraint node for the coil to wind around the square skeleton system, eliminating the need for tape connection. The device is reasonably designed, simple in structure, good in portability, high in stability, capable of saving the construction time on the tunnel site and beneficial to ensuring the accuracy of induction signals, and is suitable for large-scale promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a perspective view of a coil skeleton device for the overlapping small loop transient electromagnetic method in a tunnel;

[0019] Figure 2 It is a front view of a coil skeleton device for the overlapping small loop transient electromagnetic method in a tunnel;

[0020] Figure 3 Isometric view of the reinforcement component and the locking ring on the skeleton unit;

[0021] Figure 4 Side view of the reinforcement component and the locking ring on the skeleton unit;

[0022] Figure 5 Cross-sectional view of the reinforcement component, the locking ring and the skeleton unit in the H-H direction;

[0023] Figure 6 For Figure 5 Enlarged schematic diagram of structure A in

[0024] Figure 7 Isometric view of the rod body and the skirt provided in this embodiment;

[0025] Figure 8 Exploded view of the reinforcement component and the locking ring provided in this embodiment;

[0026] Figure 9 Isometric view of the shaping unit provided in this embodiment;

[0027] Figure 10 Isometric view of the support provided in this embodiment;

[0028] Figure 11 Schematic diagram of the cooperation between the support and the shaping unit provided in this embodiment;

[0029] Figure 12 Top view of the states of 8 skeleton units during the contraction process provided in this embodiment;

[0030] Figure 13 Stereogram of the states of 8 skeleton units during the contraction process provided in this embodiment;

[0031] Figure 14 Schematic diagram of 8 skeleton units after contraction provided in this embodiment;

[0032] In the above figures, 1 is the framework unit; 11 is the rod body; 111 is the rod shaft; 112 is the rod head; 12 is the end universal joint; 121 is the threaded sleeve; 122 is the inner shoulder; 123 is the shaft core; 124 is the T-shaped sleeve; 125 is the first annular groove; 126 is the second annular groove; 127 is the snap ring; 128 is the end hinge head; 13 is the transition universal joint; 131 is the first transition hinge head; 132 is the third annular groove; 133 is the second transition hinge head; 134 is the radial screw; 14 is the skirt plate; 141 is the perforation; 2 is the shaping unit; 21 is the C-shaped card hole; 22 is the arcuate segment; 23 is the shovel-shaped segment; 24 is the circular arc opening; 3 is the support member; 31 is the vertical segment; 32 is the S-shaped arc segment; 4 is the reinforcement assembly; 41 is the left socket; 42 is the right socket; 43 is the socket groove; 44 is the socket tooth; 45 is the key-shaped positioning groove; 46 is the key-shaped positioning projection; 47 is the counterbore; 5 is the lock ring; 51 is the M-shaped segment; 52 is the straight segment; 53 is the tenon head. Detailed implementation manners

[0033] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described below with reference to the drawings and embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments may be combined with each other. For the convenience of description, the words "upper", "lower", "left" and "right" mentioned below only represent the same directions as the upper, lower, left and right directions of the drawings themselves, and do not limit the structure.

[0034] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention may be implemented in other ways different from those described herein. Therefore, the present invention is not limited by the specific embodiments disclosed in the following specification.

[0035] Embodiment, such as Figures 1-14As shown in the figure, a coil skeleton device for the overlapping small-loop transient electromagnetic method in a tunnel provided by the present invention includes 8 skeleton units 1. The skeleton units 1 are made of non-metallic materials. The 8 skeleton units 1 are connected end to end in sequence. The skeleton unit 1 includes a rod body 11. End universal joints 12 are provided at both ends of the rod body 11. A transition universal joint 13 hinged thereto is provided at the end of one of the end universal joints 12. The transition universal joint 13 is used to connect adjacent skeleton units 1. A trumpet-shaped skirt plate 14 is provided at a position near the end of the rod body 11. A plurality of through holes 141 distributed in a circular array are provided on the skirt plate 14. The through holes 141 are used for wiring. A shaping unit 2 is provided on the outside of adjacent skeleton units 1. The shaping unit 2 is used to shape the skeleton unit 1 into a square. The shaping unit 2 is made of non-metallic material. The shaping unit 2 includes C-shaped card holes 21 provided at both ends thereof and used for quick clamping with the rod body 11. The skeleton unit 1 and the shaping unit 2 are made of non-metallic materials, which can reduce the influence of their materials on the magnetic induction signals generated by the transmitting coil and the receiving coil, and is beneficial to ensuring the efficiency of tunnel transient electromagnetic method detection.

[0036] Specifically, the present invention forms a deformable overall structure through 8 skeleton units 1 connected end to end in sequence. The skeleton unit 1 can realize rotation and folding in multiple directions through the end universal joints 12 and the transition universal joint 13, so it can be deployed and contracted synchronously; for the skeleton unit 1 in the contracted state, the 8 skeleton units 1 form a parallel relationship of 2 rows and 4 columns. The end universal joints 12 and the transition universal joint 13 are both located at both ends of the contracted whole, and the shaping unit 2 can be clamped on the rod body 11 of some of the skeleton units 1. Therefore, the 8 skeleton units 1 and the shaping unit 2 are all gathered together. Coupled with non-metallic materials such as plastics, they are light in weight and also convenient to carry. They can be deployed at the position where detection operations need to be carried out, which can save the time for building a square skeleton system on the tunnel site.

[0037] In order to better provide the framework required for coil winding, the eight skeleton units 1 in the unfolded state can form a quadrilateral structure or an octagonal structure. The included angle between adjacent skeleton units 1 makes a turn at the position of the transitional universal joint 13. Considering the detection requirements of the present invention, that is, all skeletons need to enclose a square skeleton system, so four shaping units 2 are evenly clamped on the eight skeleton units 1 to form a relatively stable square skeleton system, which is beneficial to ensuring the accuracy of the induction signal. For the skirt plate 14 on the rod body 11, the skirt plate 14 provides a constraint node for the coil to wind around the square skeleton system. The multi-turn coil can pass through the skirt plate 14 in an orderly manner without tape connection. Before the operation is completed, it can contract with the contraction of the eight skeleton units 1, is not easy to burst open and unwind, and has good stability, which is beneficial to improving the efficiency of tunnel operation. The interchangeability of the skeleton unit 1 provided by the present invention is relatively high. Therefore, when a serious quality problem occurs in a single skeleton unit 1, it can be replaced specifically to ensure the comprehensive utilization rate of the whole device.

[0038] As Figure 1 and Figures 9-11 shown, considering that the skeleton unit 1 and the shaping unit 2 are preferably made of PVC material, in order to improve the matching performance between the shaping unit 2 and the skeleton unit 1, the shaping unit 2 provided by the present invention includes an arcuate section 22. The thickness of the arcuate section 22 gradually thins from the middle to both ends. At both ends of the arcuate section 22, there are provided shovel-shaped sections 23 which are relatively flat in shape. The width of the shovel-shaped section 23 is greater than the width of the arcuate section 22. The C-shaped clamping hole 21 is arranged at the end of the shovel-shaped section 23. The shaping unit 2 provided by the present invention has a certain elasticity. Especially at the connection position between the arcuate section 22 and the shovel-shaped section 23, it can produce corresponding elastic deformation under pressure. Therefore, it will not excessively increase the shear force at the position of the C-shaped clamping hole 21 and cause the rod body 11 to break, which is beneficial to extending the comprehensive service life of the device. In tunnel operation, for the situation where handheld positioning is necessary, the arcuate section 22 provides a handheld site to facilitate keeping the entire square skeleton system in the area to be detected.

[0039] Furthermore, the arcuate section 22 provided by the present invention is provided with an arc opening 24 in the middle thereof. The arc opening 24 is arranged on the inner side of the arc of the arcuate section 22. In this way, the toughness of the arcuate section 22 can be improved, enabling it to better adapt to the dynamic pressure on the two skeleton units 1, and to a certain extent, reducing the probability of the C-shaped clamping opening and the rod body 11 being disengaged, thereby ensuring its effective real-time clamping span and further ensuring the stability of the square frame of the device.

[0040] As Figure 11As shown in the figure, a support member 3 is provided on the shaping unit 2 and is matched with its arcuate section 22 and circular arc opening 24. The support member 3 has an R-shaped structure and includes a vertical section 31. The top of the vertical section 31 is provided with an S-shaped arc section 32, and the end of the S-shaped arc section 32 bends and extends towards the end of the vertical section 31. The gap between the waist of the S-shaped arc section 32 and the middle position of the vertical section 31 is small. During the quick clamping process, this gap can be correspondingly expanded until the arcuate section 22 is clamped within the clamping range formed by the head of the S-shaped arc section 32 and the vertical section 31, and it will not come off without obvious external force. By adopting the support member 3 that can be quickly clamped with the shaping unit 2, manpower can be liberated. Especially in the case where the detection position in the tunnel is relatively narrow or there are good fulcrums, the support member 3 is clamped at the position of the circular arc opening 24, and the roots of the vertical section 31 and the S-shaped arc section 32 are supported on the tunnel wall surface, so as to ensure the stability of the square skeleton system and the position of the transmitting coil. Only by moving the position of the receiving coil can the corresponding detection operation be carried out.

[0041] Considering that the rod body 11 is made of plastic material, the straight line formed by the two skeleton units 1 on the same horizontal plane is likely to have a certain bending arc. Therefore, the present invention adopts a reinforcement component 4 to improve the straightness of a single rod body 11 in the direction of its straight line. Specifically, as Figures 1-3 and Figure 8 shown, at least one reinforcement component 4 is provided on the rod body 11. The reinforcement component 4 includes a left sleeve buckle 41 and a right sleeve buckle 42 that are relatively clamped and matched. The left sleeve buckle 41 has a semi-cylindrical structure with a pair of arcuate buckle grooves 43 provided at both ends, and the right sleeve buckle 42 has a semi-cylindrical structure with a pair of buckle teeth 44 provided at both ends for clamping with the buckle grooves 43. The cross-section where the buckle teeth 44 are located is C-shaped. The reinforcement component 4 adopts a design of being sleeved left and right, and is not restricted by the existing connection relationship of the eight skeleton units 1, and can flexibly establish a sleeved relationship with the rod body 11. Among them, the left sleeve buckle 41 and the right sleeve buckle 42 can quickly form a hugging relationship through the cooperation of the buckle grooves 43 and the buckle teeth 44 designed at their ends, and the hugging center of the two is the center of the rod body 11; generally, the overall length of the skeleton unit 1 is 1 m, and the reinforcement component 4 can be about 10 cm. The reinforcement component 4 has a certain axial length and is preferably arranged near the middle of the rod body 11, so as to reduce the probability of the rod body 11 having an obvious bending arc and is beneficial to extending the actual service life of the rod body 11.

[0042] Furthermore, a pair of key-shaped positioning grooves 45 are provided on the surface of the left sleeve buckle 41 opposite to the right sleeve buckle 42 of the present invention, and a pair of key-shaped positioning protrusions 46 are provided on the surface of the right sleeve buckle 42 opposite to the left sleeve buckle 41. By adopting the key-shaped positioning grooves 45 and the key-shaped positioning protrusions 46, a positioning effect can be achieved, avoiding obvious axial displacement between the left sleeve buckle 41 and the right sleeve buckle 42, and sharing a part of the pressure for the buckle teeth 44, reducing the probability of tearing at the root of the buckle teeth 44.

[0043] In order to improve the winding effect of the coil on the square skeleton system formed by this device, two pairs of countersunk holes 47 are provided on both the left socket 41 and the right socket 42 provided by the present invention. The countersunk holes 47 on the left socket 41 and the right socket 42 are connected by 4 symmetrically arranged locking rings 5. The locking ring 5 includes an M-shaped section 51. Both ends of the M-shaped section 51 are provided with flat sections 52 opposite to its M-shaped opening. The end of the flat section 52 is provided with a tenon 53. The M-shaped section 51 can be flipped around the cooperation center of the tenon 53 and the countersunk hole 47 to the end faces of the left socket 41 and the right socket 42. Among them, the locking ring 5 can be fitted with the left socket 41 and the right socket 42 by expanding the relative distance between the two tenons 53 at its end until the tenon 53 and a part of the flat section 52 are stuck in the countersunk hole 47, and the tension of the locking ring 5 is used to improve the connection reliability of the reinforcement component 4; at the same time, if the coil passes through the position of the locking ring 5, it can pass through from the inner direction of the ring of the locking ring 5. The locking ring 5 can press the coil on the rod body of the rod 11 by folding, and the middle point of its M shape can be stuck on the end face of the reinforcement component 4 by friction and clamping. Thus, in cooperation with the through hole 141 provided on the skirt plate 14, the winding effect of the coil on the square skeleton system can be guaranteed, which is beneficial to ensuring the accuracy of the induction signal.

[0044] In order to improve the folding performance between adjacent skeleton units 1, as Figure 6 shown, the end universal joint 12 provided by the present invention is threadedly connected to a threaded sleeve 121 provided in a counterbore at the end of the rod body 11. The inner wall of the threaded sleeve 121 is provided with an inner shoulder 122. An axially limited core 123 is provided inside the threaded sleeve 121 and axially limitedly cooperates with its inner shoulder 122. The end of the threaded sleeve 121 is provided with a T-shaped sleeve 124. The inner wall of the T-shaped sleeve 124 is provided with a plurality of first annular grooves 125. The outer wall of the axially limited core 123 is provided with a plurality of second annular grooves 126. Snap rings 127 are provided in the first annular grooves 125 corresponding to the second annular grooves 126. The T-shaped sleeve 124 is provided with an end hinge head at one end facing away from the threaded sleeve 121. Among them, the threaded sleeve 121 and the end of the rod body 11 maintain a relatively static relationship; the axially limited core 123 is a stepped shaft with a shaft shoulder design, and the shaft shoulder forms an axially limited relationship with the inner shoulder 122. On the other side of the inner shoulder 122, an axially limited relationship in the opposite direction is formed by the snap ring 127 and the T-shaped sleeve 124. Therefore, the axially limited core 123 cannot axially move in the threaded sleeve 121, but it can be guaranteed to have a rotation function; the T-shaped sleeve 124 and the end hinge head are connected by bolts, and the two can rotate synchronously, and other structures hinged to the hinge hole on the end hinge head, that is, the transition universal joint 13 can generate a folding action around the hinge hole.

[0045] Furthermore, the transitional universal joint 13 provided by the present invention includes a first transitional hinge head 131 hinged to the end hinge head. At least two third annular grooves 132 axially spaced apart are provided on the side surface of the first transitional hinge head 131. A second transitional hinge head 133 is nested on the first transitional hinge head 131. A plurality of radial screws 134 are provided on the outer side of the nested surface of the second transitional hinge head 133 and the first transitional hinge head 131. The end of the radial screw 134 is in sliding contact with the groove surface of the third annular groove 132. Among them, the relative ends of the first transitional hinge head 131 and the second transitional hinge head 133 adopt a nested design. Between the nested surfaces, through the cooperation of the third annular groove 132 and the radial screw 134, the axial movement of the first transitional hinge head 131 and the second transitional hinge head 133 can be restricted, but the two can maintain relative rotational movement. Especially when the skeleton unit 1 needs to perform an action in the folding direction, by flexibly adjusting the rotation direction of the transitional universal joint 13, a reasonable converging state can be ensured for the 8 skeleton units 1 finally.

[0046] As Figure 7 shown, the rod body 11 includes a rod head 112 and a solid rod body 111. The solid rod body 111 is beneficial to ensuring the structural strength of the rod body 11. The diameter of the rod body 111 is smaller than the diameter of the rod head 112. The skirt plate 14 is arranged at the position where the rod head 112 and the rod body 111 are connected, and its flared mouth faces the middle direction of the rod body 111. In this way, the coil turns can extend along the rod body 111 and then pass through or out of the flared mouth, so that the coil will not be folded sharply and affect the normal transmission of current.

[0047] The above is only the preferred embodiment of the present invention, and it is not a limitation of the present invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or modifications into equivalent embodiments with equivalent changes and apply them to other fields. However, as long as it does not depart from the technical solution content of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A coil skeleton device for transient electromagnetic method with overlapping small loops in a tunnel, comprising 8 skeleton units, the skeleton units being made of non-metallic materials, characterized in that, Eight skeleton units are connected end to end in sequence. The skeleton unit includes a rod body, and both ends of the rod body are provided with end universal joints. One end of one of the end universal joints is provided with a transition universal joint hinged thereto. The transition universal joint is used to connect adjacent skeleton units. The rod body is provided with a trumpet-shaped skirt plate near its end. The skirt plate is provided with a plurality of perforations distributed in a circular array. The perforations are used for wire routing. A shaping unit is arranged on the outer side of adjacent skeleton units. The shaping unit is used to shape the skeleton unit into a square. The shaping unit is made of a non-metallic material. The shaping unit includes C-shaped card holes arranged at both ends thereof and used for quickly clamping with the rod body.

2. The coil skeleton device of the overlapping small loop transient electromagnetic method in a tunnel according to claim 1, characterized in that, The shaping unit includes an arcuate section, and the thickness of the arcuate section gradually thins from the middle to both ends. Both ends of the arcuate section are provided with shovel-shaped sections. The width of the shovel-shaped section is greater than the width of the arcuate section. The C-shaped card holes are arranged at the ends of the shovel-shaped sections.

3. A coil skeleton device for the overlapping small-loop transient electromagnetic method in a tunnel according to claim 2, characterized in that, The arcuate section is provided with an arc opening in the middle thereof.

4. A coil skeleton device for the overlapping small-loop transient electromagnetic method in a tunnel according to claim 3, characterized in that, A support member is arranged on the shaping unit and is matched with its arcuate section and arc opening. The support member has an R-shaped structure and includes a vertical section. The top end of the vertical section is provided with an S-shaped arc section. The end of the S-shaped arc section bends and extends towards the end of the vertical section.

5. The coil skeleton device for the overlapping small loop transient electromagnetic method in a tunnel according to claim 1, wherein At least one reinforcement component is arranged on the rod body. The reinforcement component includes a left sleeve buckle and a right sleeve buckle that are relatively clamped and matched. The left sleeve buckle is a semi-cylindrical structure with a pair of arc-shaped buckle grooves arranged at both ends thereof. The right sleeve buckle is a semi-cylindrical structure with a pair of buckle teeth arranged at both ends thereof and used for clamping with the buckle grooves. The cross-section where the buckle teeth are located is C-shaped.

6. The coil skeleton device for the overlapping small loop transient electromagnetic method in a tunnel according to claim 5, characterized in that, The left sleeve buckle is provided with a pair of key-shaped positioning grooves on the surface opposite to the right sleeve buckle. The right sleeve buckle is provided with a pair of key-shaped positioning protrusions on the surface opposite to the left sleeve buckle.

7. A coil skeleton device for transient electromagnetic method with overlapping small loops in a tunnel according to claim 6, characterized in that, Both the left sleeve buckle and the right sleeve buckle are provided with two pairs of countersunk holes. The countersunk holes on the left sleeve buckle and the right sleeve buckle are connected by four symmetrically arranged locking rings in pairs. The locking ring includes an M-shaped section. Both ends of the M-shaped section are provided with straight-shaped sections opposite to its M-shaped opening. The end of the straight-shaped section is provided with a tenon head. The M-shaped section can be flipped around the fitting center of the tenon head and the countersunk hole to the end faces of the left sleeve buckle and the right sleeve buckle.

8. A coil skeleton device for the overlapping small-loop transient electromagnetic method in a tunnel according to claim 1, characterized in that, The end universal joint is threadedly connected to a threaded sleeve arranged in a sink groove at the end of the rod body. The inner wall of the threaded sleeve is provided with an inner shoulder. An axially limiting fit shaft core is arranged inside the threaded sleeve. The end of the threaded sleeve is provided with a T-shaped sleeve. The inner wall of the T-shaped sleeve is provided with a plurality of first annular grooves. The outer wall of the shaft core is provided with a plurality of second annular grooves. Snap rings are arranged in the corresponding first annular grooves and second annular grooves. The T-shaped sleeve is provided with an end hinge head at the end facing away from the threaded sleeve.

9. A coil skeleton device for transient electromagnetic method with overlapping small loops in a tunnel according to claim 8, characterized in that, The transition universal joint includes a first transition hinge head hinged to the end hinge head. At least two axially spaced third annular grooves are arranged on the side surface of the first transition hinge head. A second transition hinge head is nested on the first transition hinge head. A plurality of radial screws are arranged on the outer side of the nested surface of the second transition hinge head and the first transition hinge head. The end of the radial screw is in sliding contact with the groove surface of the third annular groove.

10. A coil skeleton device for the overlapping small-loop transient electromagnetic method in a tunnel according to any one of claims 1-9, characterized in that, The rod body includes a rod head and a solid rod shaft. The diameter of the rod shaft is smaller than that of the rod head. The skirt plate is arranged at the position where the rod head is connected to the rod shaft, and its flared opening faces the middle direction of the rod shaft.

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