Measuring method based on inspection well depth measuring device

Abstract

The invention relates to the technical field of engineering equipment, in particular to a measuring method based on an inspection well depth measuring device. The telemeter rod comprises a telemeter rod body, the telemeter rod body comprises a telescopic rod type structure composed of a plurality of sections of telemeter rod sleeves, and an opening and closing assembly is arranged on the telemeter rod sleeve on the outermost portion so that the telemeter rod sleeves in the contraction state can be sequentially locked from outside to inside or sequentially unlocked from inside to outside; magnetic attraction locking pieces matched with each other are arranged at the connecting positions of the head portions and the tail portions of the adjacent ruler sleeves so that the ruler sleeves in the unfolded state can be locked. The top of the outermost ruler sleeve is provided with a ruler collecting assembly, the ruler collecting assembly comprises a strong magnet capable of moving along the axial direction of the ruler sleeve, and the strong magnet can slide to the magnetic attraction locking piece to unlock the magnetic attraction locking piece and can be in magnetic attraction connection with the second section of ruler sleeve in the unfolded state. The folding and unfolding device is stable in unfolding and folding, parts contaminated with dirt do not need to be held in the unfolding and folding processes, and the influence on physical and psychological health of constructors is small.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering equipment, and particularly to a measurement method based on a measurement device for the depth of inspection wells. Background Technique

[0002] Inspection wells are provided for the convenience of maintenance and installation of power supply, water supply, drainage, sewage discharge, communication, cable TV, gas pipes, street lamp lines, etc. of urban underground infrastructure. Generally, they are located at pipe intersections, turning points, where the pipe diameter or slope changes, and at certain intervals on straight pipe segments, and are auxiliary structures for facilitating regular inspections.

[0003] In the renovation projects of municipal pipe networks and community pipe networks, before construction, it is necessary to measure the depths of rain inspection wells and sewage inspection wells. The measured data can be compared with the original design elevation of the inspection wells to judge the blockage situation of the inspection wells, and can also be used as a reference for the design depth and construction depth of new inspection wells during pipe renovation. During construction, it is also necessary to control the construction progress by measuring the depth of the inspection wells. In addition, after construction, it is also necessary to measure the depth of the inspection wells to judge whether the construction operations meet the standards.

[0004] Most of the existing inspections of inspection wells use the form of measuring with a tower ruler. Most of the existing tower ruler structures are as described in the text of a measuring tower ruler with the Chinese patent publication number CN218297137U, which is a multi-stage telescopic sleeve structure. When in use, the tower ruler can be unfolded or stored by holding and sliding the ruler body located inside, and has high portability and convenience in use. However, during actual operations, especially during the measurement operation of old sewage wells, due to a large amount of dirt in the sewage wells, which is mixed with excrement, oil stains and other filth, when the unfolded tower ruler is inserted into the sewage well and contaminated with a large amount of filth, and then the contaminated ruler body is held to store the tower ruler, it will cause the hands of construction workers to be contaminated with a large amount of filth, which not only easily causes discomfort to construction workers, but also the long-term residue of filth will lead to the invasion of germs and affect the physical health of construction workers. In addition, after the tower ruler is unfolded, the segments in the unfolded state mainly rely on friction to maintain the stability of the unfolded tower ruler. When the sludge thickness in the inspection well is large or the sludge hardness is large, it is often difficult for the bottom of the tower ruler to reach the bottom of the inspection well, resulting in insufficient accuracy of the measurement data, so it needs to be solved urgently. Summary of the Invention

[0005] In order to avoid and overcome the technical problems existing in the prior art, the present invention provides a measurement method based on a measurement device for the depth of inspection wells, which is stable in unfolding and storing, and during the unfolding and storing processes, there is no need to hold the contaminated parts, and it has less impact on the physical and mental health of construction workers.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A measuring method based on a measuring device for the depth of inspection wells, including a tower ruler body, which includes a telescopic rod structure composed of several ruler sleeves. An opening and closing component is arranged on the outermost ruler sleeve to lock the ruler sleeves in a contracted state from the outside to the inside in sequence or unlock them from the inside to the outside in sequence; magnetic attraction locking parts that cooperate with each other are arranged at the joints of the heads and tails of adjacent ruler sleeves to lock the ruler sleeves in an unfolded state; a ruler retracting component is arranged at the top of the outermost ruler sleeve, and the ruler retracting component includes a strong magnet that can move axially along the ruler sleeve. The strong magnet can slide to the magnetic attraction locking part to unlock the magnetic attraction locking part and can be magnetically connected to the second ruler sleeve in an unfolded state; the measuring method of this measuring device includes the following steps:

[0008] S1. Arrange the tower ruler body in a plumb state at the wellhead of the inspection well in a fully contracted state. Unlock the innermost ruler sleeve from the inside to the outside through the opening and closing component, so that the innermost ruler sleeve slides and unfolds in sequence under the action of gravity, and lock the unfolded ruler sleeve through the magnetic attraction locking part;

[0009] S2. When the bottom of the tower ruler body in an unfolded state abuts against the bottom of the inspection well, read the scale reading on the tower ruler body;

[0010] S3. Slide the strong magnet of the ruler retracting component downward to the magnetic attraction locking part of the second ruler sleeve in an unfolded state. Unlock the magnetic attraction locking part by the strong magnet and magnetically fix it to the second ruler sleeve in an unfolded state. Then move the ruler retracting component upward to make the second ruler sleeve in an unfolded state contract and lock it through the opening and closing component;

[0011] S4. Repeat step S3 until the tower ruler body is in a contracted state.

[0012] As a further scheme of the present invention: the opening and closing component includes an opening and closing insertion rod radially inserted into the inner cavity of the ruler sleeve, and locking insertion holes for cooperating with the insertion of the opening and closing insertion rod are arranged on the ruler sleeve.

[0013] As a further scheme of the present invention: a locking mechanism for locking the position of the opening and closing insertion rod is arranged on the outermost ruler sleeve.

[0014] As a further scheme of the present invention: the locking mechanism includes a fixing ring sleeved outside the opening and closing insertion rod and fixed to the outermost ruler sleeve, and a damping part that abuts against the opening and closing insertion rod is arranged inside the fixing ring.

[0015] As a further scheme of the present invention: annular grooves that form an interference fit with the damping part are coaxially distributed outside the opening and closing insertion rod. The annular grooves are arranged in several intervals along the length direction of the opening and closing insertion rod, and the distribution interval between adjacent annular grooves is the same as the hole depth of the locking insertion hole.

[0016] As a further solution of the present invention: The magnetic attraction locking member includes an iron column and a small magnet magnetically coupled with the iron column. A receiving blind hole distributed along the radial direction of the inner ruler sleeve is provided on the side wall of the head of the inner ruler sleeve, and the iron column slides coaxially in the inner cavity of the receiving blind hole; a locking hole is provided on the inner side wall of the tail of the ruler sleeve, and the small magnet is arranged in the locking hole; when the ruler sleeve is unfolded, the receiving blind holes and the locking holes at the head and tail of adjacent ruler sleeves are aligned, and the iron column slides under the magnetic attraction of the small magnet, so that the head and tail sections of the iron column are respectively located in the locking hole and the receiving blind hole.

[0017] As a further solution of the present invention: A positioning slider and a positioning chute that cooperate with each other are provided between adjacent ruler sleeves. The positioning chute is distributed along the axial direction of the ruler sleeve, and the tail end of the positioning chute is a sealed end, and the extreme state of the unfolding of the ruler sleeve is positioned by this sealed end, thereby positioning the alignment state between the receiving blind hole and the locking hole.

[0018] As a further solution of the present invention: The ruler retracting assembly includes a ruler retracting rod that can be inserted into the inner cavity of the ruler sleeve from the head of the ruler sleeve, and a strong magnet is hinged to the tail end of the ruler retracting rod.

[0019] As a further solution of the present invention: An upper cover is fixed to the head of the outermost ruler sleeve. A swinging jack for the ruler retracting rod to pass through and swing is provided on the upper cover. The head of the ruler retracting rod is a convex head that cannot pass through the swinging jack. A swinging chute is fixed on the ruler retracting rod along its own length direction. A guiding shaft is fixed on the hole wall of the swinging jack and inserted radially into the swinging chute. The ruler retracting rod is slidably matched with the guiding shaft through the swinging chute, and the ruler retracting rod can swing around the axis of the guiding shaft, so that the strong magnet can swing to the position of the magnetic attraction locking member.

[0020] As a further solution of the present invention: The ruler sleeve is made of a transparent material.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. During the unfolding process of the ruler sleeve, only need to hold the outermost opening and closing rod, and unlock the ruler sleeve in sequence through the opening and closing assembly, then the ruler sleeve can be automatically unfolded under the action of gravity, so that it is not necessary to hold the part contaminated with dirt during the unfolding process of the ruler sleeve. And when the construction worker retracts the ruler sleeve, only need to hold the outermost ruler sleeve, and realize the retraction of the ruler sleeve through the sliding of the strong magnet 22, thereby realizing the retraction operation of the ruler sleeve without holding the part contaminated with dirt.

[0023] 2. Magnetic attraction locking members that cooperate with each other are provided at the connection between the head and the tail of adjacent ruler sleeves to lock the ruler sleeve in the unfolded state, ensuring the stability of the ruler sleeve in the unfolded state, and preventing the ruler sleeve from being inserted downward close to the bottom of the inspection well and being restricted by impurities such as silt at the bottom of the well and unable to fully abut against the bottom of the well, thereby reducing the measurement accuracy.

[0024] 3. After the ruler sleeve is unfolded, the iron column slides into the locking hole under the magnetic attraction of the small magnet, realizing pin - type locking, which has a good locking effect and ensures the stability of the ruler sleeve in the unfolded state. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the present invention.

[0026] Figure 2 It is Figure 1 a partially enlarged schematic structural diagram of part A of

[0027] Figure 3 It is a schematic structural diagram of the connection structure between adjacent ruler sleeves in the present invention.

[0028] Figure 4 It is Figure 3 a partially enlarged schematic structural diagram of part B of

[0029] Figure 5 It is a schematic structural diagram of the middle - section ruler sleeve in the present invention.

[0030] Figure 6 It is Figure 5 a partially enlarged schematic structural diagram of part C of

[0031] Figure 7 It is a three - dimensional schematic structural diagram of the outermost ruler sleeve in the present invention.

[0032] Figure 8 It is a sectional schematic structural diagram of the outermost ruler sleeve in the present invention.

[0033] Figure 9 It is Figure 8 a partially enlarged schematic structural diagram of part D of

[0034] In the figure: 10. Tower ruler main body; 11. Ruler sleeve; 111. Locking jack; 112. Accommodating blind hole; 113. Iron column; 114. Locking hole; 115. Small magnet; 116. Positioning chute; 117. Positioning slider; 12. Upper cover; 121. Swing jack; 122. Guide shaft; 20. Retracting ruler rod; 21. Swing chute; 22. Strong magnet; 30. Opening - closing insertion rod; 31. Ring groove; 40. Fixed ring; 41. Damping member. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0036] For ease of understanding, in combination with the accompanying drawings, the specific structure and working mode of the present invention are further described as follows:

[0037] The specific structure of the present invention is referred to Figures 1-9 As shown, its main structure includes a telescopic leveling rod body 10 that can be telescopically deployed or retracted.

[0038] Among them, as Figure 1 shown, the leveling rod body 10 includes a telescopic rod structure composed of several rod sleeves 11. An opening and closing component is provided on the outermost rod sleeve 11 to lock the rod sleeves 11 in sequence from outside to inside or unlock them in sequence from inside to outside in the retracted state. When measuring the depth of the inspection well, by first unlocking the innermost rod sleeve 11, the innermost rod sleeve 11 slides and unfolds; then unlocking the adjacent inner rod sleeves 11 in sequence, so that the tail of the lowermost rod sleeve 11 abuts against the bottom of the inspection well. After the measurement is completed, only need to continuously retract the second rod sleeve 11 in the deployed state upward and lock it in sequence through the opening and closing component, and the locking after the rod sleeves 11 are retracted can be achieved.

[0039] The opening and closing component is the main structure for the part that does not need to be held and contaminated during the unfolding process of the rod sleeve 11 in this application. During the unfolding process of the rod sleeve 11, only need to hold the outermost opening and closing insertion rod 30, and unlock the rod sleeves 11 in sequence through the opening and closing component, then the rod sleeves 11 can be automatically unfolded under the action of gravity.

[0040] Specifically, as Figure 8 and Figure 9 shown, the opening and closing component includes an opening and closing insertion rod 30 radially inserted into the inner cavity of the rod sleeve 11. Locking insertion holes 111 are provided on the rod sleeve 11 for the opening and closing insertion rod 30 to insert. The above-mentioned locking or unlocking of the rod sleeves 11 in the retracted state from outside to inside or from inside to outside in sequence is achieved by means of sliding plug connection.

[0041] Furthermore, to ensure that the opening and closing insertion rod 30 maintains a relatively stable plugging state, a locking mechanism for locking the position of the opening and closing insertion rod 30 is provided on the outermost rod sleeve 11.

[0042] Preferably, as Figure 9 shown, the locking mechanism includes a fixing ring 40 sleeved outside the opening and closing insertion rod 30 and fixed to the outermost rod sleeve 11. A damping member 41 that abuts against the opening and closing insertion rod 30 is provided inside the fixing ring 40. The damping member 41 is preferably a spring piece or a rubber ring that can generate an elastic extrusion force on the opening and closing insertion rod 30.

[0043] Further, annular grooves 31 which are in transitional fit with the damping member 41 are coaxially distributed outside the opening and closing plug rod 30. A plurality of the annular grooves 31 are arranged at intervals along the length direction of the opening and closing plug rod 30, and the distribution interval between adjacent annular grooves 31 is the same as the hole depth of the locking jack 111. During use, when the damping member 41 slides into the annular groove 31, the locking effect on the opening and closing plug rod 30 can be further improved. In addition, during the sliding process of the opening and closing plug rod 30, by sliding the damping member 41 into the adjacent annular groove 31, the locking or unlocking of one scale sleeve 11 can be realized, ensuring the accuracy of the opening and closing process of the opening and closing plug rod 30.

[0044] Of course, in actual implementation, the locking mechanism can also adopt a pin shaft structure radially inserted into the opening and closing plug rod 30, as long as it can realize the sliding of the opening and closing plug rod 30 and the locking after sliding.

[0045] As Figure 3 shown, magnetic attraction locking members which cooperate with each other are arranged at the connection between the head and the tail of adjacent scale sleeves 11 to lock the scale sleeve 11 in the unfolded state.

[0046] Specifically, as Figure 4 shown, the magnetic attraction locking member includes an iron column 113 and a small magnet 115 which is magnetically attracted to the iron column 113. A receiving blind hole 112 distributed radially along the inner scale sleeve 11 is formed in the side wall of the head of the inner scale sleeve 11, and the iron column 113 slides coaxially in the inner cavity of the receiving blind hole 112; a locking hole 114 is formed in the inner side wall of the tail of the scale sleeve 11, and the small magnet 115 is arranged in the locking hole 114. When the scale sleeve 11 is unfolded, the receiving blind hole 112 and the locking hole 114 at the head and the tail of adjacent scale sleeves 11 are aligned, and the iron column 113 slides under the magnetic attraction of the small magnet 115, so that the head and tail sections of the iron column 113 are respectively located in the locking hole 114 and the receiving blind hole 112, finally realizing the locking of the scale sleeve 11 after unfolding. The plug-in locking method with the iron column 113 sliding into the locking hole 114 has a good locking effect, ensuring the stability of the scale sleeve 11 in the unfolded state, and can prevent the scale sleeve 11 from being inserted downward close to the bottom of the inspection well and being restricted by impurities such as silt at the bottom of the well and unable to be in full contact with the bottom of the well, thereby reducing the measurement accuracy.

[0047] Further, as Figure 5 and Figure 7 shown, in order to ensure the accurate alignment between the positioning receiving blind hole 112 and the locking hole 114 when the scale sleeve 11 is in the unfolded state, positioning sliders 117 and positioning chutes 116 which cooperate with each other are arranged between adjacent scale sleeves 11. The positioning chute 116 is distributed along the axial direction of the scale sleeve 11, and the tail end of the positioning chute 116 is a sealed end, and the limit state of the unfolded scale sleeve 11 is positioned by this sealed end, thereby positioning the alignment state between the receiving blind hole 112 and the locking hole 114.

[0048] Of course, in actual implementation, the locking of the magnetic attraction locking member can also be directly achieved by respectively arranging magnetic rings at the head and tail of the scale sleeve 11 that can be magnetically attracted and fixed to each other. After the scale sleeve 11 is unfolded, the magnetic attraction between the magnetic rings is utilized to realize the locking after the scale sleeve 11 is unfolded. This implementation method is convenient for processing, but the locking effect between the scale sleeves 11 is average, and it can be used as an alternative implementation method for measuring inspection wells with small silt thickness and low silt hardness.

[0049] The cooperation between the scale retracting assembly and the magnetic attraction locking member is the main structure that enables the scale sleeve 11 of the present application to be retracted without holding the parts contaminated with dirt.

[0050] As Figure 1 、 Figure 2 and Figure 8 shown, a scale retracting assembly is provided at the top of the outermost scale sleeve 11. The scale retracting assembly includes a strong magnet 22 that can move axially along the scale sleeve 11. The strong magnet 22 can slide to the magnetic attraction locking member to unlock the magnetic attraction locking member, and can be magnetically connected to the second scale sleeve 11 in the unfolded state, so that when the strong magnet 22 moves, the second scale sleeve 11 in the unfolded state can be driven to move to the contracted state. Thus, during the retraction process, first, the strong magnet 22 unlocks the magnetic attraction locking member on the second scale sleeve 11 in the current unfolded state. The preferred implementation of the magnetic attraction locking member corresponding to the present application is: by the magnetic attraction force of the strong magnet 22 being greater than that of the small magnet 115, the iron column 113 is adsorbed to be separated from the locking hole 114, thereby realizing the unlocking of the magnetic attraction locking member. After that, by using the magnetic attraction between the strong magnet 22 and the iron column 113, the fixation between the strong magnet 22 and the scale sleeve 11 is realized. At this time, when the strong magnet 22 moves upward, the second scale sleeve 11 in the unfolded state is driven to move to the contracted state. Obviously, in this implementation method, when the construction worker retracts the scale sleeve 11, only the outermost scale sleeve 11 needs to be held, and the retraction of the scale sleeve 11 is realized by the sliding of the strong magnet 22, thereby realizing the retraction operation of the scale sleeve 11 without holding the parts contaminated with dirt.

[0051] Furthermore, as Figure 8 shown, the scale retracting assembly includes a scale retracting rod 20 that can be inserted into the inner cavity of the scale sleeve 11 from the head of the scale sleeve 11. The strong magnet 22 is hingedly connected to the tail end of the scale retracting rod 20, so as to facilitate the strong magnet 22 to be in contact with the inner side edges of different scale sleeves 11.

[0052] Furthermore, the head of the outermost scale sleeve 11 is fixed with an upper cover 12. An oscillation jack 121 for the retractable scale rod 20 to penetrate and swing is provided on the upper cover 12. The head of the retractable scale rod 20 is a convex head that cannot pass through the oscillation jack 121, which can locate the limit position of the downward sliding of the retractable scale rod 20. A swing chute 21 arranged along the length direction of the retractable scale rod 20 is fixed on the retractable scale rod 20. A guide shaft 122 inserted radially along the swing chute 21 is fixed on the hole wall of the oscillation jack 121. The retractable scale rod 20 is slidably engaged with the guide shaft 122 through the swing chute 21, and the retractable scale rod 20 can swing around the axis of the guide shaft 122, so that the strong magnet 22 can swing to the magnetic attraction locking part.

[0053] It is worth mentioning that in this application, the scale sleeve 11 is made of a transparent material, which is convenient for observing the position of the strong magnet 22 in the scale sleeve 11, so as to operate the retractable scale rod 20 to realize the contraction operation of the scale sleeve 11.

[0054] Specifically, the measuring method of the measuring device includes the following steps:

[0055] S1. Arrange the tower ruler main body 10 in a fully retracted state vertically at the wellhead of the inspection well. Unlock the innermost scale sleeve 11 from the inside to the outside through the opening and closing component, so that the innermost scale sleeve 11 slides and unfolds in sequence under the action of gravity, and lock the unfolded scale sleeve 11 through the magnetic attraction locking part;

[0056] S2. When the bottom of the tower ruler main body 10 in the unfolded state abuts against the bottom of the inspection well, read the scale reading on the tower ruler main body 10;

[0057] S3. Slide the strong magnet 22 of the retracting component downward to the magnetic attraction locking part of the second scale sleeve 11 in the unfolded state. Unlock the magnetic attraction locking part by the strong magnet 22, and magnetically fix it with the second scale sleeve 11 in the unfolded state. Then move the retracting component upward to make the second scale sleeve 11 in the unfolded state contract, and lock it through the opening and closing component;

[0058] S4. Repeat step S3 until the tower ruler main body 10 is in a retracted state.

[0059] Of course, for those skilled in the art, the present invention is not limited to the details of the above exemplary embodiments, but also includes the same or similar structures that can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0060] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0061] The technologies, shapes, and structures not detailedly described in the present invention are all well-known technologies.

Claims

1. A measurement method based on a manhole depth measurement device, characterized in that It includes a leveling rod main body (10), which includes a telescopic rod structure composed of several rod sleeves (11). An opening and closing assembly is provided on the outermost rod sleeve (11) to lock the rod sleeves (11) in the contracted state from the outside to the inside in sequence or unlock them from the inside to the outside in sequence; Magnetic locking parts that cooperate with each other are provided at the joints of the heads and tails of adjacent rod sleeves (11) to lock the rod sleeves (11) in the unfolded state; A retracting ruler assembly is provided at the top of the outermost rod sleeve (11). The retracting ruler assembly includes a strong magnet (22) that can move axially along the rod sleeve (11). The strong magnet (22) can slide to the magnetic locking part to unlock the magnetic locking part and can be magnetically connected to the second rod sleeve (11) in the unfolded state; The measuring method of this measuring device includes the following steps: S1. Place the leveling rod main body (10) in a plumb position at the wellhead of the inspection well in a fully contracted state. Unlock the innermost rod sleeve (11) from the inside to the outside through the opening and closing assembly, so that the innermost rod sleeve (11) slides and unfolds successively under the action of gravity, and lock the unfolded rod sleeve (11) through the magnetic locking part; S2. When the bottom of the leveling rod main body (10) in the unfolded state abuts against the bottom of the inspection well, read the scale reading on the leveling rod main body (10); S3. Slide the strong magnet (22) of the retracting ruler assembly down to the magnetic locking part of the second rod sleeve (11) in the unfolded state. Unlock the magnetic locking part by the strong magnet (22) and magnetically fix it to the second rod sleeve (11) in the unfolded state. Then move the retracting ruler assembly upward to make the second rod sleeve (11) in the unfolded state contract and lock it through the opening and closing assembly; S4. Repeat step S3 until the leveling rod main body (10) is in a contracted state.

2. The measurement method of a measurement device based on the inspection well depth measurement according to claim 1, characterized in that, The opening and closing assembly includes an opening and closing insertion rod (30) radially inserted into the inner cavity of the rod sleeve (11), and a locking insertion hole (111) for cooperating with the insertion of the opening and closing insertion rod (30) is provided on the rod sleeve (11).

3. A measurement method based on the inspection well depth measurement device according to claim 2, characterized in that, A locking mechanism for locking the position of the opening and closing insertion rod (30) is provided on the outermost rod sleeve (11).

4. A measurement method based on the inspection well depth measurement device according to claim 3, characterized in that, The locking mechanism includes a fixing ring (40) sleeved outside the opening and closing insertion rod (30) and fixed to the outermost rod sleeve (11), and a damping part (41) abuting against the opening and closing insertion rod (30) is arranged inside the fixing ring (40).

5. A measuring method based on the inspection well depth measuring device according to claim 4, characterized in that, A ring groove (31) that forms an interference fit with the damping part (41) is coaxially distributed outside the opening and closing insertion rod (30). The ring grooves (31) are arranged in several intervals along the length direction of the opening and closing insertion rod (30), and the distribution interval between adjacent ring grooves (31) is the same as the hole depth of the locking insertion hole (111).

6. A measurement method based on the inspection well depth measurement device according to any one of claims 1-5, characterized in that, The magnetic attraction locking member includes an iron column (113) and a small magnet (115) magnetically coupled with the iron column (113). A receiving blind hole (112) radially distributed along the inner sleeve (11) is formed in the side wall of the head of the inner scale sleeve (11), and the iron column (113) slides coaxially in the inner cavity of the receiving blind hole (112); a locking hole (114) is formed in the inner side wall of the tail of the scale sleeve (11), and the small magnet (115) is arranged in the locking hole (114); when the scale sleeve (11) is unfolded, the receiving blind holes (112) and the locking holes (114) at the head and tail of adjacent scale sleeves (11) are aligned, and the iron column (113) slides under the magnetic attraction of the small magnet (115) so that the head and tail sections of the iron column (113) are respectively located in the locking hole (114) and the receiving blind hole (112).

7. A measuring method based on the inspection well depth measuring device according to claim 6, characterized in that A positioning slider (117) and a positioning chute (116) which cooperate with each other are arranged between adjacent scale sleeves (11). The positioning chute (116) is distributed along the axial direction of the scale sleeve (11), and the tail end of the positioning chute (116) is a closed end, and the extreme state of the unfolding of the scale sleeve (11) is positioned by the closed end, so as to position the alignment state between the receiving blind hole (112) and the locking hole (114).

8. A measuring method based on a manhole depth measuring device according to any one of claims 1-5, characterized in that, The retractable scale assembly includes a retractable scale rod (20) that can be inserted into the inner cavity of the scale sleeve (11) from the head of the scale sleeve (11), and a strong magnet (22) is hingedly connected to the tail end of the retractable scale rod (20).

9. A measuring method based on the inspection well depth measuring device according to claim 4, characterized in that An upper cover (12) is fixed to the head of the outermost scale sleeve (11). A swinging jack (121) for the retractable scale rod (20) to pass through and swing is arranged on the upper cover (12). The head of the retractable scale rod (20) is a convex head that cannot pass through the swinging jack (121). A swinging chute (21) is fixed on the retractable scale rod (20) along its own length direction. A guiding shaft (122) is fixed on the hole wall of the swinging jack (121) and inserted radially into the swinging chute (21). The retractable scale rod (20) is slidably matched with the guiding shaft (122) through the swinging chute (21), and the retractable scale rod (20) can swing around the axis of the guiding shaft (122) so that the strong magnet (22) can swing to the position of the magnetic attraction locking member.

10. A measurement method based on a manhole depth measurement device according to any one of claims 1-5, characterized in that, The scale sleeve (11) is made of a transparent material.

Images