阅读说明：本技术 一种纵向距离检测系统及其孔深测量方法 (Longitudinal distance detection system and hole depth measurement method thereof ) 是由 魏凌峰 于 2021-09-10 设计创作，主要内容包括：本发明公开了一种纵向距离检测系统及其孔深测量方法,属于测量技术领域。该系统包括基架和绳索,所述基架上设有放线组件、控制器、长度检测组件、称重组件、手动驱使组件和自动驱使组件,所述手动驱使组件和自动驱使组件均可以通过传动组件驱使放线组件正反转,所述绳索卷绕在放线组件上,所述绳索的一端依次绕过长度检测组件和称重组件后连接有重锤。采用重锤先触孔底,再缓慢回升一定距离的方式确定测量终止点,解决了绳索会在重锤惯性作用下多释放一段长度的问题,消除了重锤的惯性影响,大大提高了孔深检测精度。采用手动方式能够快速将重锤下放至其顶面与孔口端面共面的位置,即测量起始点位置,操作简单、省时,有助于提高孔深检测效率。(The invention discloses a longitudinal distance detection system and a hole depth measurement method thereof, and belongs to the technical field of measurement. The system comprises a base frame and a rope, wherein a pay-off assembly, a controller, a length detection assembly, a weighing assembly, a manual driving assembly and an automatic driving assembly are arranged on the base frame, the manual driving assembly and the automatic driving assembly can drive the pay-off assembly to rotate positively and negatively through a transmission assembly, the rope is wound on the pay-off assembly, and a heavy hammer is connected to one end of the rope after the length detection assembly and the weighing assembly are sequentially wound. The measuring termination point is determined by the way that the heavy hammer firstly touches the bottom of the hole and then slowly rises for a certain distance, so that the problem that the rope can be released for a section of length under the inertia effect of the heavy hammer is solved, the inertia influence of the heavy hammer is eliminated, and the hole depth detection precision is greatly improved. Adopt manual mode can transfer its top surface to fast and the coplanar position of drill way terminal surface with the weight, measure the starting point position promptly, easy operation, save time help improving hole depth detection efficiency.)

1. A longitudinal distance detection system, characterized by: including bed frame (1) and rope (8), be equipped with unwrapping wire subassembly, controller (2), length detection subassembly, weighing component, manual subassembly and the automatic subassembly of ordering about on bed frame (1), manual subassembly and the automatic subassembly of ordering about all can order about the unwrapping wire subassembly through drive assembly just reversing about ordering about the subassembly, rope (8) are convoluteed on the unwrapping wire subassembly, be connected with weight (5) after length detection subassembly and the weighing component are walked around in proper order to the one end of rope (8).

2. The longitudinal distance detection system of claim 1, wherein: the length detection assembly comprises a roller B (10) and a rotary encoder (11), a V-shaped groove is formed in the circumferential direction of the outer circular surface of the roller B (10), the roller B (10) is connected with the base frame (1) through a support B, the rotary encoder (11) is arranged on the support B and is coaxially connected with the roller B (10), and the rotary encoder (11) is electrically connected with the controller (2); all be equipped with support A in length detection subassembly's both sides on bed frame (1), the activity is equipped with wire wheel (9) on support A, and the elevation of wire wheel (9) is greater than gyro wheel B (10).

3. The longitudinal distance detection system of claim 1, wherein: the weighing assembly comprises a roller A (6), a V-shaped groove is formed in the circumferential direction of the outer circular surface of the roller A (6), the roller A (6) is connected with the base frame (1) through a weighing sensor (7), and the weighing sensor (7) is electrically connected with the controller (2); be equipped with display screen (3) and battery (4) on bed frame (1), display screen (3) and controller (2) electric connection, battery (4) and controller (2), display screen (3) electric connection.

4. The longitudinal distance detection system of claim 1, wherein: the automatic driving assembly comprises a stepping motor (17) and a driving gear A (18), the stepping motor (17) is arranged on the base frame (1), the driving gear A (18) is sleeved on an output shaft of the stepping motor (17), and the stepping motor (17) is electrically connected with the controller (2); the manual driving assembly comprises a driving shaft (20), the middle of the driving shaft (20) is movably connected with the base frame (1), one end of the driving shaft (20) is sleeved with a driving gear B (19), and the other end of the driving shaft is provided with a crank (21).

5. The longitudinal distance detection system of claim 4, wherein: the transmission assembly comprises a transmission shaft (15) and a driven gear (16), the transmission shaft (15) is movably arranged on the base frame (1), one end of the transmission shaft (15) is sleeved with a synchronous pulley B (22), the driven gear (16) is movably sleeved on the transmission shaft (15) and is in sliding connection with the base frame (1) through a connecting block (14), the driven gear (16) can be meshed with a driving gear A (18) and a driving gear B (19), and a row of locking bolts are in threaded connection with the base frame (1) at positions corresponding to the connecting block (14); the middle part of the transmission shaft (15) is provided with a spline, and the driven gear (16) is correspondingly provided with a spline groove; the paying-off assembly comprises a middle shaft, a winding drum (12) and a synchronous belt wheel A (13), wherein the middle shaft is movably arranged on the base frame (1), the winding drum (12) is sleeved on the middle shaft, and the synchronous belt wheel A (13) is sleeved at one end of the middle shaft and is connected with a synchronous belt wheel B (22) through a synchronous belt.

6. A hole depth measuring method of a longitudinal distance detection system is characterized in that: the method comprises the following main steps:

A. determining a measurement starting point: the manual driving component drives the pay-off component to rotate forwards through the transmission component, the heavy hammer (5) is located at a proper position of the orifice, and the controller (2) records relevant data of the length detection component at the moment to serve as a measurement starting point;

B. and (3) lowering a heavy hammer: the automatic driving component drives the pay-off component to rotate positively through the transmission component, and the heavy hammer (5) is quickly lowered to the bottom of the hole;

C. determining a measurement termination point: the automatic driving component drives the pay-off component to rotate reversely through the transmission component, the weight (5) is lifted to a proper position through slow rotation, and the controller (2) records the relevant data of the length detection component at the moment to be used as a measurement termination point;

D. determining hole depth and retrieving rope: the controller (2) automatically calculates the hole depth, and simultaneously controls the automatic driving component to drive the pay-off component to reversely rotate so as to quickly retract the rope (8) and the heavy hammer (5).

7. The hole depth measuring method of a longitudinal distance detecting system according to claim 6, characterized in that: and in the step A, when the top surface of the heavy hammer (5) is flush with the end surface of the hole, the rotary encoder (11) records the forward rotation angle of the roller B (10) and transmits the forward rotation angle to the controller (2) as a measurement starting value.

8. The hole depth measuring method of a longitudinal distance detecting system according to claim 6, characterized in that: and B, when the weight value detected by the load cell (7) is smaller than the gravity of the heavy hammer (5), indicating that the heavy hammer (5) reaches the bottom of the hole.

9. The hole depth measuring method of a longitudinal distance detecting system according to claim 6, characterized in that: and in the step C, when the gravity value detected by the weighing sensor (7) is changed from increasing to decreasing, the rotary encoder (11) records the forward rotation angle of the roller B (10) at the moment and transmits the forward rotation angle to the controller (2) as a measurement termination value.

10. The hole depth measuring method of a longitudinal distance detecting system according to claim 6, characterized in that: in the step D, the controller (2) sets the formula L as (theta)_{Final (a Chinese character of 'gan')}-θ_{Starting point})÷360×C_Wheel+H_HammerCalculating the hole depth, where L is the hole depth, θ_{Final (a Chinese character of 'gan')}Is the normal rotation angle theta of the roller B (10) at the end point_{Starting point}As the starting point, the forward rotation angle of the roller B (10), C_{The wheel is}Circumference of outer circle surface of bottom of V-shaped groove on roller B (10), H_HammerIs the height of the weight (5),and displaying the value of the hole depth L on the display screen (3).

Technical Field

The invention relates to a longitudinal distance detection system and a hole depth measurement method thereof, and belongs to the technical field of measurement.

Background

Laser measuring instruments, infrared measuring instruments, microwave measuring instruments and the like are widely applied to the measuring field, and can accurately measure the height, distance and the like of surface buildings, but the laser measuring instruments, the infrared measuring instruments, the microwave measuring instruments and the like cannot measure the unpredictable depth below the surface of the ground, such as the depth measurement of deep holes, lakes, rivers and the like.

Chinese patent publication No. CN212806887U discloses a pile foundation hole depth measuring device, in which, when in use, the whole device is placed beside the pile foundation hole, and the reel is aligned right above the pile foundation hole. Then put into pile foundation hole with the pouring weight with the rope even, the pouring weight can be because the dead weight drives the reel rotation, rope downstream, is connected through rotary damper between reel and the mounting bracket simultaneously, and the rope is tightened and with a constant speed downstream in the pile foundation hole under the effect of the dead weight of pouring weight and rotary damper finally. After the weight is at the bottom, the dead weight of the weight can not be applied to the rope any more, and the rotary damper is used for keeping the rope straight than the locking drum. The rope drives the roller to rotate in the descending movement process of the rope, the rotation angle of the roller is detected through the photoelectric encoder, and then the descending distance of the rope can be calculated through the controller according to the radius of the roller.

However, this measuring device has the following disadvantages:

first, in the moment the pouring weight reaches the bottom of the hole, the rope can release a section of length more under the inertia effect of pouring weight to be in the bending state, lead to the gyro wheel to have rotated certain number of turns or angle more, further lead to the hole depth detection precision greatly to reduce.

And secondly, the rope needs to be recovered by manually cranking the crank, so that the labor intensity is high and the working efficiency is low.

Chinese patent publication No. CN111006630A discloses a device and a method for detecting depth of sludge in a suction well of a coal mine pump room, which are applied to deep hole detection, and have the following problems: firstly, when hole depth detection is carried out, a connecting cable between a mining intrinsic safety type tension sensor and a mining explosion-proof and intrinsic safety type programmable control box needs to be synchronously placed in a deep hole, operation is inconvenient, and the connecting cable can cause interference on a measured value of the mining intrinsic safety type tension sensor; secondly, the mining intrinsic safety type tension sensor is directly installed on a cable rope and is easy to shake and swing along with the cable rope, so that the tension detection value of the mining intrinsic safety type tension sensor fluctuates, and the hole depth detection precision is reduced; thirdly, the difficulty of controlling the motor to find the initial point (i.e. the reference point) is high, the time is consumed, and when the heavy hammer reaches the bottom of the deep hole, a section of cable rope is released more, so that the hole depth detection precision is low.

Disclosure of Invention

In order to solve the technical problem, the invention provides a longitudinal distance detection system and a hole depth measurement method thereof.

The invention is realized by the following technical scheme:

the utility model provides a longitudinal distance detecting system, includes bed frame and rope, be equipped with unwrapping wire subassembly, controller, length detection subassembly, the subassembly of weighing, manual subassembly and the automatic subassembly of ordering about on the bed frame, manual subassembly and the automatic subassembly of ordering about all can order about the unwrapping wire subassembly through drive assembly just reversing, the rope is convoluteed on the unwrapping wire subassembly, the one end of rope is walked around in proper order and is connected with the weight behind length detection subassembly and the subassembly of weighing.

The length detection subassembly includes gyro wheel B and rotary encoder, is equipped with the V-arrangement groove along circumference on gyro wheel B's the outer disc, and gyro wheel B passes through support B to be connected with the bed frame, and rotary encoder establishes on support B to with gyro wheel B coaxial coupling, rotary encoder and controller electric connection all are equipped with support A in length detection subassembly's both sides on the bed frame, and the activity is equipped with the wire wheel on support A, and the elevation of wire wheel is greater than gyro wheel B.

The weighing component comprises a roller A, a V-shaped groove is formed in the outer circular surface of the roller A along the circumferential direction, the roller A is connected with the base frame through a weighing sensor, the weighing sensor is electrically connected with the controller, a display screen and a storage battery are arranged on the base frame, the display screen is electrically connected with the controller, and the storage battery is electrically connected with the controller and the display screen.

The automatic driving component comprises a stepping motor and a driving gear A, the stepping motor is arranged on the base frame, the driving gear A is sleeved on an output shaft of the stepping motor, the stepping motor is electrically connected with the controller, the manual driving component comprises a driving shaft, the middle of the driving shaft is movably connected with the base frame, a driving gear B is sleeved at one end of the driving shaft, and a crank is arranged at the other end of the driving shaft.

The transmission assembly comprises a transmission shaft and a driven gear, the transmission shaft is movably arranged on the base frame, a synchronous belt pulley B is sleeved at one end of the transmission shaft, the driven gear is movably sleeved on the transmission shaft and is connected with the base frame in a sliding mode through a connecting block, the driven gear can be meshed with a driving gear A and a driving gear B, a row of locking bolts are in threaded connection with the position corresponding to the connecting block on the base frame, a spline is arranged at the middle of the transmission shaft, a spline groove is correspondingly formed in the driven gear, the paying-off assembly comprises a middle shaft, a winding drum and the synchronous belt pulley A, the middle shaft is movably arranged on the base frame, the winding drum is sleeved on the middle shaft, the synchronous belt pulley A is sleeved at one end of the middle shaft, and is connected with the synchronous belt pulley B through a synchronous belt.

A hole depth measuring method of a longitudinal distance detection system comprises the following main steps:

A. determining a measurement starting point: the manual driving component drives the pay-off component to rotate forwards through the transmission component, so that the heavy hammer is located at a proper position of the orifice, and the controller records the relevant data of the length detection component at the moment to serve as a measurement starting point;

B. and (3) lowering a heavy hammer: the automatic driving component drives the pay-off component to rotate forwards through the transmission component, and the heavy hammer is quickly lowered to the bottom of the hole;

C. determining a measurement termination point: the automatic driving component drives the pay-off component to rotate reversely through the transmission component, the weight hammer is lifted to a proper position through slow rotation, and the related data of the length detection component at the moment is recorded through the controller to serve as a measurement termination point;

D. determining hole depth and retrieving rope: the controller automatically calculates the hole depth, and simultaneously controls the automatic driving assembly to drive the pay-off assembly to rotate reversely, so as to quickly retract the rope and the heavy hammer.

And B, when the top surface of the heavy hammer is flush with the end surface of the orifice in the step A, the rotary encoder records the forward rotation angle of the roller B and transmits the forward rotation angle to the controller as a measurement starting value.

And B, when the weight value detected by the weighing sensor is smaller than the gravity of the weight, indicating that the weight reaches the bottom of the hole.

And C, when the gravity value detected by the weighing sensor is changed from increasing to decreasing, the rotary encoder records the positive rotation angle of the roller B at the moment and transmits the positive rotation angle to the controller as a measurement termination value.

In the step D, the controller sets (θ) according to the formula L_{Final (a Chinese character of 'gan')}-θ_{Starting point})÷360×C_Wheel+H_HammerCalculating holeDepth, where L is the hole depth, θ_{Final (a Chinese character of 'gan')}The normal rotation angle of the roller B is the end point_{Starting point}The initial point is the positive rotation angle of the roller B, the C wheel is the perimeter of the outer circle surface at the bottom of the V-shaped groove on the roller B, and H_HammerThe height of the weight is shown, and the value of the hole depth L is displayed on the display screen.

The invention has the beneficial effects that:

1. the measuring termination point is determined by the way that the heavy hammer firstly touches the bottom of the hole and then slowly rises for a certain distance, so that the problem that the rope can be released for a section of length under the inertia effect of the heavy hammer is solved, the inertia influence of the heavy hammer is eliminated, and the hole depth detection precision is greatly improved.

2. Adopt manual mode can transfer its top surface to fast and the coplanar position of drill way terminal surface with the weight, measure the starting point position promptly, easy operation, save time help improving hole depth detection efficiency.

3. Through controller control step motor, realize automatically that the weight is transferred fast, slowly gyration is promoted and the quick process of withdrawing of rising, obviously improved hole depth detection efficiency, greatly reduced intensity of labour, and can realize the weight position accurate control.

4. The weighing sensor is directly arranged on the base frame, the interference is less, the detection value is stable and reliable, and the hole depth detection precision is ensured.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of an assembly structure of the base frame, the manual actuating assembly, the automatic actuating assembly and the transmission assembly according to the present invention;

fig. 3 is a schematic structural diagram of a roller B according to the present invention.

In the figure: 1-base frame, 2-controller, 3-display screen, 4-storage battery, 5-weight, 6-roller A, 7-weighing sensor, 8-rope, 9-wire guide wheel, 10-roller B, 11-rotary encoder, 12-winding drum, 13-synchronous pulley A, 14-connecting block, 15-transmission shaft, 16-driven gear, 17-stepping motor, 18-driving gear A, 19-driving gear B, 20-driving shaft, 21-crank and 22-synchronous pulley B.

Detailed Description

The technical solution of the present invention is further described below, but the scope of the claimed invention is not limited to the described.

As shown in fig. 1 to 3, the longitudinal distance detecting system according to the present invention includes a base frame 1 and a rope 8, wherein the base frame 1 is provided with a pay-off assembly, a controller 2, a length detecting assembly, a weighing assembly, a manual driving assembly and an automatic driving assembly, the manual driving assembly and the automatic driving assembly can drive the pay-off assembly to rotate forward and backward through a transmission assembly, the rope 8 is wound around the pay-off assembly, and one end of the rope 8 sequentially bypasses the length detecting assembly and the weighing assembly and is connected with a weight 5.

Length detecting element includes gyro wheel B10 and rotary encoder 11, it has the V-arrangement groove to process along circumference on gyro wheel B10's the outer disc, gyro wheel B10 passes through support B and is connected with bed frame 1, rotary encoder 11 installs on support B, and with gyro wheel B10 coaxial coupling, rotary encoder 11 and controller 2 electric connection, all install support A in length detecting element's both sides on bed frame 1, movable mounting has wire wheel 9 on the support A, and wire wheel 9's elevation is greater than gyro wheel B10. In use, roller B10 is free to rotate and the V-shaped groove in roller B10 provides a stop for the radial direction of the cord 8. The rope 8 is guided by the two wire guide wheels 9, the wrap angle of the rope 8 on the roller B10 is increased, and the rope 8 is prevented from slipping relative to the roller B10, so that the rotary encoder 11 can accurately detect the rotation angle of the roller B10.

The weighing component includes gyro wheel A6, and it has the V-arrangement groove to process along circumference on gyro wheel A6's the outer disc, and gyro wheel A6 passes through weighing sensor 7 and is connected with bed frame 1, and weighing sensor 7 and 2 electric connection of controller install display screen 3 and battery 4 on the bed frame 1, display screen 3 and 2 electric connection of controller, battery 4 and controller 2, 3 electric connection of display screen. In use, the load cell 7 is used to weigh the weight 5 and the rope 8 between the weight 5 and the roller A6.

The automatic driving assembly comprises a stepping motor 17 and a driving gear A18, the stepping motor 17 is installed on the base frame 1, the driving gear A18 is sleeved on an output shaft of the stepping motor 17, the stepping motor 17 is electrically connected with the controller 2, the manual driving assembly comprises a driving shaft 20, the middle of the driving shaft 20 is movably connected with the base frame 1, one end of the driving shaft 20 is sleeved with a driving gear B19, and the other end of the driving shaft is provided with a crank 21. The stepping motor 17 is used for driving the driving gear A18 to rotate, so that the winding and unwinding linear speed and the rotation angle of the winding drum 12 can be conveniently controlled, the lifting speed and the lifting height of the heavy hammer 5 can be conveniently and accurately controlled, and the hole depth detection precision is ensured. Through the manual drive shaft 20 of crank 21 and driving gear B19 rotation, can transfer weight 5 fast to its top surface and the coplanar position of drill way terminal surface, measure the initial point position promptly, easy operation, save time help improving hole depth detection efficiency.

The transmission assembly comprises a transmission shaft 15 and a driven gear 16, the transmission shaft 15 is movably mounted on the base frame 1, one end of the transmission shaft 15 is sleeved with a synchronous pulley B22, the driven gear 16 is movably sleeved on the transmission shaft 15 and is in sliding connection with the base frame 1 through a connecting block 14, the driven gear 16 can be meshed with a driving gear A18 and a driving gear B19, a row of locking bolts are in threaded connection with the position, corresponding to the connecting block 14, on the base frame 1, a spline is machined in the middle of the transmission shaft 15, a spline groove is correspondingly machined on the driven gear 16, the paying-off assembly comprises a middle shaft, a winding drum 12 and a synchronous pulley A13, the middle shaft is movably mounted on the base frame 1, the winding drum 12 is sleeved on the middle shaft, the synchronous pulley A13 is sleeved on one end of the middle shaft and is connected with a synchronous pulley B22 through a synchronous belt. When the automatic power transmission device is used, power transmission is achieved through the transmission assembly, the driven gear 16 can be meshed with the driving gear A18 and the driving gear B19, manual driving and automatic driving switching is achieved, and the connecting block 14 is locked through the locking bolt after switching in place.

A hole depth measuring method of a longitudinal distance detection system comprises the following main steps:

A. determining a measurement starting point: the manual driving component drives the pay-off component to rotate forwards through the transmission component, so that the heavy hammer 5 is located at a proper position of the orifice, and the controller 2 records the relevant data of the length detection component at the moment to be used as a measurement starting point;

B. and (3) lowering a heavy hammer: the automatic driving component drives the pay-off component to rotate forwards through the transmission component, and the heavy hammer 5 is quickly lowered to the bottom of the hole;

C. determining a measurement termination point: the automatic driving component drives the pay-off component to rotate reversely through the transmission component, the weight 5 is lifted to a proper position through slow rotation, and the controller 2 records the relevant data of the length detection component at the moment to be used as a measurement termination point; when the device is used, the speed of the slow rotation and lifting of the heavy hammer 5 is 6-60 mm/min.

D. Determining hole depth and retrieving rope: the controller 2 automatically calculates the hole depth, and simultaneously controls the automatic driving component to drive the pay-off component to reversely rotate so as to rapidly retract the rope 8 and the heavy hammer 5.

In step a, when the top surface of the weight 5 is flush with the end surface of the opening, the rotary encoder 11 records the normal rotation angle of the roller B10 and transmits the recorded normal rotation angle to the controller 2 as the measurement start value.

In step B, when the weight value detected by the load cell 7 is smaller than the gravity of the weight 5, it indicates that the weight 5 has reached the bottom of the hole. In use, the weight sensor 7 is used for weighing the weight of the weight 5 and the rope 8 between the weight 5 and the roller A6, and during the process of lowering the weight 5, the detection value of the weight sensor 7 gradually increases and is larger than the weight of the weight 5 along with the gradual increase of the length of the rope 8 between the weight 5 and the roller A6, so when the detection value of the weight sensor 7 is smaller than the weight of the weight 5, the weight 5 reaches the bottom of the hole.

In the step C, at the moment when the gravity value detected by the load cell 7 changes from increasing to decreasing, the rotary encoder 11 records the forward rotation angle of the roller B10 at that time, and transmits the forward rotation angle to the controller 2 as a measurement termination value. During the process of slowly rotating and lifting the weight 5 on the drum 12, the detection value of the load cell 7 is gradually increased, when the weight 5 completely falls off the bottom of the hole and further rises, the length of the rope 8 between the weight 5 and the roller a6 is gradually decreased, and the detection value of the load cell 7 is correspondingly gradually decreased, so that the moment when the detection value of the load cell 7 is gradually decreased from the increasing moment to the decreasing moment, i.e. the critical point at which the weight 5 just falls off the bottom of the hole, is also the measurement end point.

In step D, the controller 2 sets (θ) to L_{Final (a Chinese character of 'gan')}-θ_{Starting point})÷360×C_Wheel+H_HammerCalculating the hole depth, where L is the hole depth, θ_{Final (a Chinese character of 'gan')}To end the normal rotation angle of the roller B10,θ_{starting point}The initial point is the positive rotation angle of the roller B10, the wheel C is the perimeter of the outer circle surface of the bottom of the V-shaped groove on the roller B10, H_HammerIs the height of the weight 5, and the value of the hole depth L is displayed on the display screen 3. When in use, C_WheelAnd H_HammerIs a known quantity, θ_{Starting point}And theta_{Final (a Chinese character of 'gan')}Detected by the rotary encoder 11 and transmitted to the controller 2.

Specifically, the rope 8 is a kevlar rope.

The working principle or the using process of the longitudinal distance detection system is as follows:

the locking bolts are loosened, the driven gear 16 is pushed to be engaged with the driving gear B19, and the corresponding locking bolts are tightened to fix the connecting block 14. The crank 21 is rotated to drive the winding drum 12 to rotate forward through the driving shaft 20, the driving gear B19, the driven gear 16, the transmission shaft 15, the synchronous pulley B22, the synchronous belt, the synchronous pulley A13 and the middle shaft, so that the weight 5 is gradually lowered to the measurement starting point position.

After the controller 2 records the forward rotation angle of the roller B10 when the weight 5 reaches the measurement start point, the driven gear 16 is pushed to the position engaged with the driving gear a18, and the locking bolt is tightened to fix the connecting block 14. Then, the controller 2 controls the stepping motor 17 to act, so that torque is transmitted to the winding drum 12 through the driving gear a18, the driven gear 16, the transmission shaft 15, the synchronous pulley B22, the synchronous belt, the synchronous pulley a13 and the middle shaft, the winding drum 12 rotates forwards or backwards, the heavy hammer 15 is rapidly lowered to the bottom of the hole, slowly rotates and is lifted to a measurement termination point position, and the heavy hammer is rapidly retracted.

The longitudinal distance detection system and the hole depth measurement method thereof have the following beneficial effects:

1. the measuring termination point is determined by the way that the heavy hammer 5 firstly contacts the bottom of the hole and then slowly rises for a certain distance, so that the problem that the rope can be released for a section of length under the inertia effect of the heavy hammer 5 is solved, the inertia influence of the heavy hammer 5 is eliminated, and the hole depth detection precision is greatly improved.

2. Adopt manual mode can transfer its top surface to fast and the coplanar position of drill way terminal surface with weight 5, measure the starting point position promptly, easy operation, save time help improving hole depth detection efficiency.

3. Through controller 2 control step motor 17, realize weight 5 automatically and transfer fast, slowly turn around to promote and rise fast and withdraw the process, obviously improved hole depth detection efficiency, greatly reduced intensity of labour, and can realize weight 5 position accurate control.

4. The weighing sensor 7 is directly arranged on the base frame 1, the interference is less, the detection value is stable and reliable, and the hole depth detection precision is ensured.