Anchord cable continuous tensioning jack and step-by-step climbing method thereof

Abstract

The present application relates to the technical fields of coal mine prestressed anchoring, and discloses a continuous tensioning jack for anchor cable and a step-by-step climbing method thereof, comprising: an inner cylinder, a middle cylinder and an outer cylinder in coaxial sleeve type layout and nested; a tool anchor and a reset spring accommodated in the inner cylinder, the middle cylinder being connected with an anchor releasing ring extending into the inner cylinder, linear displacement of the middle cylinder relative to the inner cylinder changing mechanical contact state of the anchor releasing ring and the tool anchor, so as to realize holding and loosening of the steel strand; a top pressure device fixed at the front end of the middle cylinder, and a climbing handle pivoted to the outer structure of the outer cylinder. The climbing method is as follows: in the out-of-cylinder working condition, the top pressure device is used to form a reverse support to pull outwards, and in the retraction working condition, the climbing handle is used to be hung on the external anchor device to form a hanging fulcrum to slide inwards. The present application realizes automatic anchor releasing by internal mechanical linkage, and realizes continuous step-by-step climbing without lifting by means of fulcrum alternation, so as to reduce the machine volume and the construction operation intensity.

Description

Technical Field

[0001] This invention relates to the field of prestressed anchoring technology in coal mines, specifically to a continuous tensioning jack for anchor cables and its step-climbing method. Background Technology

[0002] In coal mine roadway support engineering, prestressed anchor cables are widely used for the reinforcement of the roof and surrounding rock. Anchor cable tensioning jacks are the core construction equipment for applying prestress to steel strands. With increasing stress in deep mining, the demand for long-stroke, high-stress anchoring operations is growing. Traditional anchor cable tensioning jacks typically use conventional hydraulic cylinder structures. After completing a single short-stroke tensioning operation, anchor retraction and cylinder resetting are required before the next tensioning can proceed. This reciprocating cycle usually requires manual disassembly of the clamps or assisted anchor retraction by construction personnel, resulting in cumbersome operations, high work intensity, and low tensioning efficiency.

[0003] Meanwhile, to meet the demands of large tonnage and long tensioning strokes, traditional jacks often require increased physical length and radial dimensions of the hydraulic cylinders, resulting in a significant increase in the overall volume and weight of the jacks. In the narrow cross-sections and confined working spaces of underground coal mines, transporting and operating such cumbersome equipment is extremely difficult. Furthermore, during the cylinder retraction phase after a single tensioning cycle, the front end of a traditional jack loses its thrust support to the external rock mass or anchorage, making the jack itself prone to slipping backward along the steel strand under its own weight. To maintain the jack's working position for the next tensioning cycle, manual lifting is usually required throughout the process, which not only significantly depletes the physical strength of the workers but also poses certain safety hazards under high-pressure working conditions. Therefore, the industry needs a tensioning device that can reduce the frequency of operational intervention, adapt to confined spaces, and possess autonomous stepping capabilities. Summary of the Invention

[0004] The technical problem solved by this invention is that the existing anchor tensioning equipment is large in size and weight, making it difficult to meet the construction needs of narrow cross sections such as underground coal mines; and the anchor removal and cylinder reversal operations in traditional construction operations rely on frequent manual intervention, which is labor-intensive and cannot achieve automatic continuous step-by-step climbing of the equipment along the steel strand without lifting.

[0005] To address the above problems, the present invention provides the following technical solution:

[0006] The first aspect of this invention provides a continuous anchor cable tensioning jack, comprising: The inner cylinder, middle cylinder, and outer cylinder are nested in a coaxial sleeve-like layout. The outer cylinder has an oil port on its side wall that connects to the internal chambers of the multi-stage hydraulic cylinder. The tool anchor housed inside the inner cylinder and the return spring that applies axial thrust to the tool anchor are provided. The middle cylinder is connected to an anchor removal ring that extends into the inner cylinder. The linear displacement of the middle cylinder relative to the inner cylinder changes the mechanical contact state between the anchor removal ring and the tool anchor, thereby achieving the clamping and loosening of the steel strand passing through the central hole. The top pressure device is fixed to the front end of the middle cylinder, and the climbing handle is pivotally connected to the external structure of the outer cylinder.

[0007] As a preferred embodiment of the first aspect of the present invention, a sliding guide structure with clearance fit is formed between the outer side wall of the inner cylinder and the inner side wall of the middle cylinder, and between the outer side wall of the middle cylinder and the inner side wall of the outer cylinder; the pressure-bearing structure of the middle cylinder cooperates with the inner cylinder and the outer cylinder to divide the overall enclosed space inside the multi-stage cylinder into a rodless chamber and a rod chamber; the oil port includes an outlet oil port communicating with the rodless chamber and a return oil port communicating with the rod chamber.

[0008] As a preferred embodiment of the first aspect of the present invention, an anchor cup and a spring seat are coaxially mounted inside the inner cylinder; a tapered hole is machined on the inner wall of the anchor cup, and the tool anchor is slidably accommodated in the tapered hole of the anchor cup; the main body of the spring seat is fixedly assembled in the inner hole at the rear end of the inner cylinder, and the return spring is accommodated inside the spring seat and abuts against the rear end face of the tool anchor; the unloading ring is arranged in front of the tool anchor.

[0009] As a preferred technical solution of the first aspect of the present invention, when the middle cylinder moves forward linearly relative to the inner cylinder, the unloading ring disengages from the mechanical contact with the tool anchor, and the return spring releases elastic potential energy to continuously push the tool anchor to slide forward along the inner conical surface of the anchor cup, forcing the tool anchor to generate radial contraction displacement inward, and initially gripping the steel strand passing through the central hole. When the middle cylinder retracts relative to the inner cylinder, the rear end face of the unloading ring abuts against and overcomes the axial thrust of the return spring, forcibly pushing the tool anchor out of the tight tapered hole area at the front end of the anchor cup, thereby releasing the radial rigid constraint imposed by the anchor cup on the outside.

[0010] As a preferred embodiment of the first aspect of the present invention, the outer wall cone angle of the tool anchor is set to be smaller than the equivalent friction angle between the tool anchor and the anchor cup contact surface, thereby forming a friction self-locking constraint mechanism to prevent the tool anchor from slipping backward inside the anchor cup.

[0011] As a preferred embodiment of the first aspect of the present invention, the top pressure device is a hollow tubular or sleeve-shaped structure, and a through hole is provided in the center of the top pressure device for the steel strand to pass through without interference; the inner contour of the climbing handle is machined with a geometric groove, and the geometric groove is a bayonet structure adapted to the outer steps of the external J-shaped anchor.

[0012] As a preferred embodiment of the first aspect of the present invention, the main body of the climbing handle adopts a symmetrical split structure, and the root of the climbing handle is pivotally connected to be opened and closed through a rotating component.

[0013] The second aspect of this invention provides a step-climbing method for a continuous anchor cable tensioning jack, applied to the continuous anchor cable tensioning jack described in the first aspect, comprising the following alternating cyclic steps: Under the tensioning condition, the multi-stage hydraulic cylinder performs the extension action, and the top pressure device abuts against the end face of the external J-type anchor to form the first rigid force support point. The internal components complete the clamping of the steel strand, and rely on the first rigid force support point to perform axial extension outward. In the retraction stepping mode, the multi-stage hydraulic cylinder performs a retraction action, using the second suspension limiting fulcrum formed by the climbing handle and the J-type anchor step to take over the overall weight. Under the interference of the anchor retraction, the internal components loosen the steel strand and slide inward along the stretched and fixed steel strand, causing the overall shell to move axially towards the J-type anchor along the fixed steel strand.

[0014] As a preferred embodiment of the second aspect of the present invention, under the condition of cylinder tensioning, it specifically includes: High-pressure hydraulic oil is guided into the rodless chamber inside the multi-stage cylinder assembly. Under the action of fluid pressure, the middle cylinder is driven to overcome resistance and extend along the axial direction of the steel strand. The top pressure device fixed at its front end is attached to the end face of the J-type anchor. As the middle cylinder extends, the anchor unloading ring moves forward and disengages from the tool anchor. The internal locking mechanism quickly and radially grips the steel strand passing through the central hole. Based on this fulcrum, the actuator drives the locking mechanism and the clamped steel strand to move backward as a whole, applying axial tension to the steel strand.

[0015] As a preferred embodiment of the second aspect of the present invention, in the retraction stepping condition, it specifically includes: Under the reverse drive of the hydraulic force in the rod chamber, the drive cylinder retracts, the top pressure device loses thrust support, and the climbing handle in the closed state rigidly interferes with the step part of the J-type anchor to take over the load. The unloading ring, which moves with the middle cylinder, abuts against the tool anchor, and the mechanical thrust generated overcomes the effect of the return spring, forcibly pushing the tool anchor out of the conical hole area and releasing the radial clamping of the steel strand. The climbing handle is attached to the J-type anchor to keep the overall shell in place, while the internal cylinder and the reset tool anchor slide inward along the steel strand.

[0016] This invention provides a continuous anchor cable tensioning jack and its step-climbing method. It has the following beneficial effects: 1. The present invention sets up a displacement interference type locking mechanism inside the jack. It uses the relative displacement between the middle cylinder and the inner cylinder to drive the movement of the anchor unloading ring. Through mechanical linkage, it changes the position of the tool anchor in the anchor cup, thereby completing the clamping and loosening of the steel strand. This structure eliminates the manual intervention in the traditional anchor unloading and cylinder reversing process, reducing the intensity of construction work.

[0017] 2. This invention, by setting up a top pressure device and a climbing handle, uses the top pressure device to abut against the external anchor to form a reverse thrust support during the cylinder tensioning condition, and uses the climbing handle to hang on the anchor step to form a suspended load-bearing support during the retraction condition. By relying on the alternating conversion of the force fulcrum, the reciprocating motion of the hydraulic cylinder is converted into the continuous stepping displacement of the jack along the steel strand, thus realizing the lifting operation without lifting.

[0018] 3. The present invention adopts a coaxial sleeve layout in which the inner cylinder, middle cylinder and outer cylinder are nested in sequence. The spatial overlap and clearance fit of the multi-stage oil cylinders form a linear drive foundation. This structure reduces the radial dimension of the jack body and the total weight of the equipment while ensuring the hydraulic pressure bearing area, thus meeting the construction operation needs of narrow cross sections such as underground coal mines. Attached Figure Description

[0019] Figure 1 This is a block diagram of the overall architecture of an automatic continuous anchor cable tensioning system according to an embodiment of the present invention; Figure 2 This is a flowchart illustrating the operation of an automatic continuous anchor cable tensioning system according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of a continuous tensioning jack according to an embodiment of the present invention.

[0020] Among them, 1. Top pressure device; 2. Anchor unloading ring; 3. Climbing handle; 4. Anchor cup; 5. Tool anchor; 6. Spring seat; 8. Inner cylinder; 9. Middle cylinder; 10. Outer cylinder; 12. Cylinder outlet port; 13. Cylinder return port; 15. Steel strand; 16. J-type anchor; 100. External power oil source; 200. Hydraulic logic control assembly; 300. Actuation assembly. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] See attached document Figure 1 The present invention provides an automatic continuous tensioning system for anchor cables, which may include an external power oil source 100, a hydraulic logic control assembly 200, and an execution assembly 300.

[0023] The external power source 100 serves as the basic power generation unit of the system, used to output high-pressure fluid. The output end of the external power source 100 is connected to the oil inlet end of the hydraulic logic control assembly 200.

[0024] The hydraulic logic control assembly 200 receives high-pressure fluid from the external power source 100 and regulates and distributes the flow direction and pressure of the high-pressure fluid. The working port of the hydraulic logic control assembly 200 is connected to the hydraulic port of the actuator assembly 300.

[0025] The actuator assembly 300, as the mechanical work unit of the system, receives hydraulic fluid distributed by the hydraulic logic control assembly 200 and converts the fluid pressure into mechanical energy for linear reciprocating motion. The actuator assembly 300 is coaxially sleeved on the outside of the steel strand 15 to complete the anchoring and axial pulling operations of the steel strand 15.

[0026] See attached document Figure 2 The macroscopic workflow of an automatic continuous anchor tensioning system can specifically include the following steps: S100, The operator passes the steel strand 15 through the center hole of the actuator assembly 300 and completes the initial positioning; S200, external power oil source 100 supplies oil, hydraulic logic control assembly 200 controls hydraulic oil to enter the oil inlet chamber of execution assembly 300, the oil cylinder inside execution assembly 300 extends along the axial direction of steel strand 15 under hydraulic drive, the locking mechanism inside execution assembly 300 undergoes mechanical linkage under the action of displacement difference, generates radial clamping force on steel strand 15, and completes the clamping action; S300, the internal cylinder of the actuator assembly 300 extends continuously, and the front end of the actuator assembly 300 abuts against the end face of the external J-type anchor 16 to form a reverse mechanical fulcrum. Based on this fulcrum, the actuator assembly 300 drives the locking mechanism and the clamped steel strand 15 to move backward as a whole, applying axial tension to the steel strand 15 to complete a single tensioning stroke. S400 After the single tensioning stroke is completed, the hydraulic logic control assembly 200 switches the direction of the hydraulic fluid, and the hydraulic oil enters the return oil chamber of the execution assembly 300. The inlet oil chamber is depressurized, and the internal cylinder of the execution assembly 300 is axially retracted by the hydraulic action. The internal locking mechanism of the execution assembly 300 then undergoes reverse mechanical interference, releasing the radial clamping state of the steel strand 15 and loosening the steel strand 15. S500 During the retraction of the internal cylinder of the actuator assembly 300, the external cooperating structure of the actuator assembly 300 forms a suspension support on the J-type anchor 16. Using this suspension support as a mechanical fulcrum, the overall shell of the actuator assembly 300 moves axially toward the working surface relative to the fixed steel strand 15, completing one stepping action. S600 and hydraulic logic control assembly 200 alternately perform oil supply and reversing operations, while execution assembly 300 cyclically repeats the above clamping, tensioning, releasing and stepping actions. The system utilizes the alternating conversion of the fulcrum to superimpose the short strokes of a single cylinder, thereby realizing the continuous stepping displacement of execution assembly 300 along steel strand 15 and the continuous tensioning operation of steel strand 15. S700, the system executes a tension termination operation. At the end of the cyclic climbing tensioning, when it is determined that the tension force output by the system to the steel strand 15 has reached the target value expected during construction, the above cyclic operation is stopped. S800, the system performs a machine retraction and reset operation. After the multi-stage hydraulic cylinder inside the actuator assembly 300 is fully retracted to its initial position, the oil supply circuit of the external power oil source 100 is shut off, and the actuator assembly 300 is controlled to release and detach from the steel strand 15, completing the continuous tensioning and step-by-step construction operation of the entire anchor cable.

[0027] See attached document Figure 3 In this embodiment, in the automatic continuous tensioning system for anchor cables provided by the present invention, the outer shell and the pressure-bearing body of the execution assembly 300 are jointly composed of a multi-stage hydraulic cylinder assembly and a matching guide structure.

[0028] The multi-stage hydraulic cylinder assembly adopts a coaxial sleeve-type layout design. As a specific structural form, the multi-stage hydraulic cylinder assembly includes an inner cylinder 8, a middle cylinder 9, and an outer cylinder 10, all of which are hollow cylindrical tubular structures. In terms of spatial assembly, the inner cylinder 8, middle cylinder 9, and outer cylinder 10 are nested radially from the inside out, with the central axis of the steel strand 15 as the reference. Specifically, the inner cylinder 8 is coaxially arranged on the innermost side and provides a central through hole for the steel strand 15 to pass through; the middle cylinder 9 is fitted onto the outer side of the inner cylinder 8; and the outer cylinder 10 is fitted onto the outermost side of the middle cylinder 9.

[0029] In the aforementioned nested structure, an inner sliding mating surface is formed between the outer wall of the inner cylinder 8 and the inner wall of the middle cylinder 9, while an outer sliding mating surface is formed between the outer wall of the middle cylinder 9 and the inner wall of the outer cylinder 10. To ensure the smooth reciprocating motion of the cylinders, both the inner and outer sliding mating surfaces are clearance mated. Guide rings and seals are provided between the mating surfaces, thus forming a sliding guide structure. The guide rings are used to limit the radial displacement of each stage of the cylinder during axial sliding, while the seals are used to prevent leakage of hydraulic fluid in the mating clearances. Regarding the specific material selection and slot installation method for the guide rings and seals, those skilled in the art can perform conventional selection and matching based on the actual working pressure. Their selection and installation are well-known techniques in the field and will not be elaborated upon here.

[0030] The outer cylinder 10 has an outlet port 12 and a return port 13 on its side wall. The outlet port 12 penetrates the side wall of the outer cylinder 10 and connects to the rodless chamber inside the multi-stage cylinder. Correspondingly, the return port 13 penetrates the side wall of the outer cylinder 10 and connects to the rod chamber inside the multi-stage cylinder. The outlet port 12 and the return port 13 constitute a physical channel for high-pressure fluid to enter and exit the multi-stage cylinder assembly.

[0031] In conjunction with the aforementioned coaxial sleeve layout, the multi-stage hydraulic cylinder assembly inside the actuator 300 needs a specific structure to reduce motion friction and maintain a sealed state for the high-pressure fluid in order to achieve smooth reciprocating motion during relative axial sliding.

[0032] A specific radial clearance is provided between the outer wall of the inner cylinder 8 and the inner wall of the middle cylinder 9, thus forming an inner sliding mating surface. Similarly, a radial clearance is provided between the outer wall of the middle cylinder 9 and the inner wall of the outer cylinder 10, forming an outer sliding mating surface. As a preferred embodiment, annular mounting grooves are machined on the corresponding metal surfaces of both the inner and outer sliding mating surfaces, and guide rings and seals are embedded within the annular mounting grooves.

[0033] The guide ring is embedded between adjacent cylinders to provide radial rigidity support when the inner cylinder 8, middle cylinder 9, and outer cylinder 10 slide relative to each other, thereby preventing axial misalignment or mechanical jamming of the multi-stage cylinder assembly under eccentric loads. The seal is tightly fitted to the mating surfaces where relative sliding occurs, preventing internal oil leakage of high-pressure hydraulic fluid between different pressure chambers and preventing fluid leakage to the external environment. The specific material selection and cross-sectional shape design of the guide ring and seal can be conventionally matched by those skilled in the art based on the target working pressure set by the system. The material selection and installation process are well-known technologies in the field and will not be elaborated upon here.

[0034] To create the sealed volume required for hydraulic operation, the intermediate cylinder 9 typically incorporates a pressure-bearing step or piston end face. This pressure-bearing structure of the intermediate cylinder 9, in conjunction with the outer wall of the inner cylinder 8 and the inner wall of the outer cylinder 10, divides the overall enclosed space inside the multi-stage cylinder into a rodless chamber and a rod chamber. From the general principle of hydraulic volume change, as the intermediate cylinder 9 moves axially, the internal physical volumes of the rodless and rod chambers alternately expand and contract.

[0035] As the physical interface for realizing the aforementioned volume change and fluid transmission, the outer cylinder 10 has an outlet port 12 and a return port 13 machined on its side wall. The internal channel of the outlet port 12 penetrates the side wall structure of the outer cylinder 10 and communicates with the rodless chamber within its internal space. When the system is in the tensioning operation phase, the outlet port 12 constitutes the oil inlet channel for high-pressure fluid to enter the rodless chamber. Correspondingly, the internal channel of the return port 13 also penetrates the side wall structure of the outer cylinder 10 and communicates with the rod chamber within its internal space. After a single tensioning stroke, the return port 13 constitutes the oil inlet channel for high-pressure fluid to enter the rod chamber.

[0036] In actual fluid control processes, the hydraulic fluid interaction process of the system is manifested as follows: Under the tensioning condition of cylinder exit, the hydraulic logic control assembly 200 controls the high pressure fluid to be injected into the rodless chamber of the multi-stage cylinder assembly through the cylinder exit port 12. At this time, the cylinder return port 13 is connected to the low pressure return oil pipeline. The residual fluid inside the rod chamber is squeezed by the middle cylinder 9 and discharged through the cylinder return port 13, so that the middle cylinder 9 can overcome the friction and extend outward. In the retraction and anchoring condition, the hydraulic logic control assembly 200 performs reversing adjustment. High-pressure fluid is injected into the rod chamber of the multi-stage cylinder assembly through the return cylinder oil port 13. At this time, the cylinder outlet oil port 12 is connected to the low-pressure return oil pipeline. The high-pressure fluid inside the rodless chamber is discharged and depressurized through the cylinder outlet oil port 12, causing the middle cylinder 9 to retract inward and return to its original position under hydraulic action.

[0037] In terms of force transmission, the automatic continuous tensioning system of anchor cables mainly utilizes the volume change in the sealed chamber to convert fluid pressure into linear mechanical tension, thereby achieving effective anchoring and tensioning of the steel strand 15.

[0038] From the perspective of the conversion principle between fluid mechanics and rigid body statics, after hydraulic fluid enters a closed volumetric chamber, it accumulates on the effective area of ​​the movable part, forming a normal force. To more clearly illustrate this force transmission mechanism, the hydraulic drive force transmission process inside a multi-stage cylinder assembly is specifically manifested as follows: The high-pressure fluid output by the external power oil source 100 is guided into the rodless chamber by the hydraulic logic control assembly 200, so that the static pressure of the fluid inside the rodless chamber gradually increases and reaches the set working threshold. Subsequently, the fluid pressure accumulated in the sealed rodless cavity directly acts on the end face of the middle cylinder 9 located inside the cavity, and the product of the pressure and the area of ​​the end face generates a hydraulic thrust extending outward along the axial direction of the steel strand 15. This causes the middle cylinder 9 to slide forward under the drive of the aforementioned hydraulic thrust. At this time, after deducting the mechanical friction resistance generated when the guide ring and the seal slide relative to each other, the thrust is converted into an effective tension load output outward by the entire actuator assembly 300.

[0039] Having clarified the aforementioned power conversion mechanism, a static calculation model for the output tension of the multi-stage hydraulic cylinder assembly can be established. Typically, the effective tension force generated by the multi-stage hydraulic cylinder assembly mainly depends on the working pressure input to the hydraulic system and the physical structural dimensions of the middle cylinder 9 itself. The calculation of this effective tension force satisfies the following formula: ; In the formula, Represents the effective tensile force output by the multi-stage hydraulic cylinder assembly; This represents the working hydraulic pressure inside the rodless chamber. This represents the effective pressure-bearing area of ​​cylinder 9 within the rodless chamber; This represents the mechanical transmission efficiency constant of the multi-stage hydraulic cylinder assembly. As a supplementary explanation, the mechanical transmission efficiency constant... The specific value is usually determined empirically based on the sliding friction resistance coefficient of the seal under a specific working pressure, and its range is usually set between 0.85 and 0.95.

[0040] To further quantify the application of this mechanical transmission model in practical engineering, this embodiment sets specific structural parameters for the actuator assembly 300. As a preferred embodiment, the effective pressure-bearing area of ​​the cylinder 9 within the rodless chamber is designed to be 57.35 square centimeters. It is worth noting that, considering the limited fluid supply pressure of some construction site foundation pump stations, the system can increase the final input pressure to the rodless chamber through a built-in or external booster circuit. In this embodiment, the system's set basic inlet pressure threshold is between 15 MPa and 20 MPa. Combined with the set booster area ratio (i.e., booster multiple) of 2.5, the target working pressure within the rodless chamber can be stably set to 40 MPa. Substituting the above parameters into the mechanical calculation model, the system is expected to output an effective tensile force of 200 kN.

[0041] The above parameter settings fully demonstrate the space utilization advantage of the coaxial sleeve drive structure. Through the spatial nesting design of multi-stage cylinders, the system maintains an effective bearing area of ​​57.35 square centimeters to ensure an output pulling force of 200 kN, while setting the maximum extension and retraction stroke of a single cylinder to 100 mm. Combined with this structural form, the overall weight of the actuator assembly 300 can typically be controlled within 12.5 kg. This combination of mechanical parameters and physical dimensions effectively balances the output pulling force requirements with the goal of lightweight equipment, thus helping to meet the construction operation needs in narrow cross-sections or confined spaces such as underground coal mines.

[0042] Regarding the internal clamping structure, the actuator assembly 300 is equipped with a displacement interference type locking mechanism. Based on the general mechanical principles of wedge force amplification and displacement interference, this mechanism utilizes the axial spatial arrangement and physical constraints between the internal components to establish clamping and release conditions for the steel strand 15.

[0043] The core components of the locking mechanism include the anchor cup 4, the tool anchor 5, the spring seat 6, and the anchor release ring 2. These core components are sequentially threaded around the outside of the steel strand 15 along the axial direction, with the central axis of the steel strand 15 as the reference. In terms of overall spatial layout, these core components are all placed in the innermost layer of the multi-stage cylinder assembly, i.e., inside the inner cylinder 8, to obtain radial physical protection and axial support for the structure.

[0044] Anchor cup 4 is coaxially mounted inside inner cylinder 8. Preferably, the outer wall of anchor cup 4 and the inner wall of inner cylinder 8 are axially and radially fixed together by fasteners such as threads, steps, or snap rings. This assembly method allows anchor cup 4 to stably transfer the load to inner cylinder 8 under high tensile stress. The inner wall of anchor cup 4 is machined with a tapered hole, which forms a mechanical base for accommodating and compressing the clamping piece.

[0045] The tool anchor 5 is slidably accommodated within the conical hole of the anchor cup 4. The outer conical surface of the tool anchor 5 is adapted to the inner conical surface of the anchor cup 4, forming a wedge-shaped mating surface that can slide relative to each other. From the physical phenomenon of mechanical clamping, when the tool anchor 5 moves towards the small end of the conical hole of the anchor cup 4 under axial thrust, the conical mating surface forces the inner diameter of the tool anchor 5 to contract, thereby generating radial pressure on the steel strand 15 passing through it. Regarding the specific multi-lobed clamping structure of the tool anchor 5 and the toothed design on the inner side of the clamping plates to increase friction, those skilled in the art can conventionally select and match according to the standard specifications of the steel strand 15. Its specific lobed structure and surface hardening treatment are well-known technologies in the art and will not be elaborated here.

[0046] To provide the tool anchor 5 with the initial preload to maintain its clamping state, a spring seat 6 is positioned behind the tool anchor 5. The main body of the spring seat 6 is fixedly mounted in the inner bore at the rear end of the inner cylinder 8, and a compressed return spring is housed inside. One end of the return spring abuts against a reference surface machined inside the spring seat 6, while the other end continuously presses against the rear end face of the tool anchor 5. Relying on the elastic potential energy released by the return spring, the system can continuously apply an axial thrust to the tool anchor 5, moving it forward toward the working end, forcing the tool anchor 5 to maintain its tendency to wedge tightly into the tapered hole of the anchor cup 4.

[0047] An anchor-removing ring 2 is arranged in front of the tool anchor 5. Unlike the components fixed inside the inner cylinder 8, the anchor-removing ring 2 is structurally connected to the middle cylinder 9. The outer edge of the anchor-removing ring 2 is directly connected to or extended and fixed to the inner wall or front face of the middle cylinder 9 through a connecting rod structure. At the same time, the rear end face of the anchor-removing ring 2 faces the front end face of the tool anchor 5, and the two maintain a certain axial distance in the initial or tensioned state. Through this cross-component mechanical assembly method, the anchor-removing ring 2 is physically freed from the constraint of the inner cylinder 8 and moves synchronously with the linear displacement of the middle cylinder 9. When the middle cylinder 9 retracts relative to the inner cylinder 8, the axial distance between the anchor-removing ring 2 and the tool anchor 5 is eliminated, and the rear end face of the anchor-removing ring 2 can directly abut and push the tool anchor 5, thus forming the hardware basis for implementing mechanical interference and anchor-removing actions.

[0048] Based on the aforementioned axial spatial assembly structure, the displacement interference type locking and unanchoring mechanism achieves automatic clamping and loosening of the steel strand 15 through the relative displacement difference of its internal components.

[0049] The spatial motion mechanism triggered by this mechanical linkage mainly relies on the relative linear displacement between the middle cylinder 9 and the inner cylinder 8 to change the internal force balance state of the locking assembly. In order to clearly reveal the internal linkage logic of the mechanism under different operating conditions, this process can be specifically decomposed into two dynamic operating conditions: radial clamping and anchor release.

[0050] When the system performs the cylinder tensioning operation, the spatial movement process of the internal components is as follows: The external high-pressure fluid drives the middle cylinder 9 to move forward in a linear displacement toward the external J-shaped anchor 16. Since the anchor unloading ring 2 is physically connected to the middle cylinder 9, the anchor unloading ring 2 moves forward synchronously with the middle cylinder 9. As the anchor unloading ring 2 moves forward, the interference force that originally acted on the front end face of the tool anchor 5 is eliminated, and the two are no longer in mechanical contact. After losing the axial restraint of the front unloading ring 2, the compressed reset spring inside the spring seat 6 releases its elastic potential energy and continues to push the tool anchor 5 to slide forward along the inner conical surface of the anchor cup 4. Furthermore, under the physical action of the wedge effect, the inner conical surface of the anchor cup 4 forces each clamp of the tool anchor 5 to produce radial contraction displacement inward, thereby initially clamping the steel strand 15 passing through the central hole and completing the radial clamping and locking before the system is subjected to force.

[0051] Accordingly, at the end of a single tensioning stroke, when the system performs a return reset operation, the dynamic triggering process for anchor release is as follows: The hydraulic logic control assembly 200 changes the fluid flow direction, drives the middle cylinder 9 to retract backward, and in turn drives the unloading ring 2 assembled on it to move backward in the opposite direction. As the retraction displacement of the middle cylinder 9 relative to the inner cylinder 8 increases, the rear end face of the anchor ring 2 gradually abuts against the front end face of the tool anchor 5 housed in the inner cylinder 8. This causes the mechanical thrust generated by the continuous retraction of the anchor ring 2 to overcome the forward axial thrust of the return spring inside the spring seat 6, forcibly pushing the tool anchor 5 to move axially backward relative to the anchor cup 4, causing it to exit the tight tapered hole area at the front end of the anchor cup 4. Finally, as the tool anchor 5 retracts from the tapered hole region, the radial rigid constraint imposed on its exterior by the anchor cup 4 is released. As a well-known mechanical structure in the art, the tool anchor 5 typically has elastic expansion rings, such as O-rings or ring springs, embedded around its multi-lobed clamping plates. After the inward pressure from the external tapered hole is removed, relying on the pre-stored expansion and contraction stress of the elastic components between the multi-lobed clamping plates and the relative friction between the clamping plates and the steel strand 15, the tool anchor 5 radially expands outward, thus completely releasing its physical clamping of the steel strand 15.

[0052] Through the aforementioned displacement interference mechanism, the actuator 300 automatically clamps and releases the steel strand 15 during the natural extension and retraction of the hydraulic cylinder, relying on the inherent mechanical linkage of its internal components. This internal structural linkage design eliminates the need for frequent manual intervention in anchor removal and cylinder reversal operations required by traditional machinery in each tensioning cycle, thereby helping to reduce the intensity of construction work and improve the continuity of the tensioning process.

[0053] In this embodiment, the system needs to maintain a relatively static state between the steel strand 15 and the tool anchor 5 when performing axial tensioning operations. To prevent relative slippage between the two under high loads, the locking and unanchoring mechanism incorporates a friction self-locking mechanical constraint mechanism in its design.

[0054] As the geometric basis for realizing the aforementioned self-locking mechanism, the outer wall cone angle of the tool anchor 5 is designed to be smaller than the equivalent friction angle between the contact surfaces of the tool anchor 5 and the anchor cup 4. In mechanical force analysis, the equivalent friction angle is a critical angle determined by the material properties and surface roughness between the two mechanical contact surfaces. When the cone angle of the tool anchor 5 is within this critical angle, the tool anchor 5 will form a self-locking effect within the cone hole of the anchor cup 4. To meet this self-locking condition and in conjunction with actual processing technology, as a specific structural parameter, the outer wall cone angle of the tool anchor 5 is usually set within the range of 5 to 15 degrees. With the above angle combination, even if the external environment causes vibration or tension fluctuations, the tool anchor 5 is unlikely to slip backward inside the anchor cup 4, thus providing stable boundary conditions for tensioning operations.

[0055] Under the protection of the self-locking effect, the dynamic force transformation process of the anchoring interface is specifically manifested as follows: As the actuator assembly 300 moves backward, the axial tensile load applied by the multi-stage cylinder assembly to the steel strand 15 gradually increases; Directly affected by the internal structural linkage, the increasing axial tensile force is transmitted to the tool anchor 5 through the steel strand 15, causing the tool anchor 5 to have a physical tendency to wedge further into the depth of the cone hole of the anchor cup 4. At this time, the wedge mechanism formed by the tool anchor 5 and the anchor cup 4 generates a force amplification effect, which makes the axial tension of the system greater, and the radial clamping force applied by the tool anchor 5 to the steel strand 15 more intense. This causes the radial clamping force to be converted into static friction between the inner wall of the tool anchor 5 and the outer surface of the steel strand 15, thus maintaining the relative stillness of the interface between the two throughout the tensioning cycle.

[0056] To ensure the reliability of the clamping action under extreme conditions, the radial clamping force generated by the wedge mechanism must satisfy specific rigid static conditions. Specifically, the maximum static friction at the interface must theoretically be greater than or equal to the axial tensile load applied by the system. The mechanical constraints satisfy the following formula: ; In the formula, The maximum static friction force at the interface between tool anchor 5 and steel strand 15; This represents the equivalent static friction coefficient between the contact surfaces of the two objects. The radial positive pressure exerted by the tool anchor 5 on the steel strand 15 represents the radial positive pressure applied by the tool anchor 5. This represents the axial tensile load applied backward by the multi-stage hydraulic cylinder assembly.

[0057] In practical engineering applications, the equivalent static friction coefficient between contact surfaces The specific value is mainly affected by the roughness of the inner surface of the tool anchor 5, the shape of the tooth pattern, and the surface condition of the steel strand 15. To ensure that the above constraint inequality holds true under various working conditions, those skilled in the art can effectively improve the equivalent static friction coefficient by machining specific interlocking teeth on the inner wall surface of the tool anchor 5 and combining it with a surface hardening treatment process. Through this optimization of the physical structure, the system is expected to ensure that the maximum static friction force always covers the peak tensile load. The specific machining parameters and hardness standards for the surface teeth are well-known technologies in the field of mechanical manufacturing and will not be elaborated here.

[0058] Regarding the external reaction support structure, in this embodiment, when the actuator 300 applies a high-load axial tensile force to the steel strand 15, it needs to rely on an external stable physical support to withstand the reaction force. To construct this mechanical support, a pressure device 1 is provided at the front end of the actuator 300.

[0059] As a specific spatial assembly and connection method, the top pressure unit 1 is coaxially mounted on the front end face of the intermediate cylinder 9. Considering the movement space requirements of the internal mechanism, the top pressure unit 1 is usually designed as a hollow tubular or sleeve-shaped structure with a through hole in the center for the steel strand 15 to pass through without interference. At the same time, this hollow structure can also reserve the necessary relative movement and clearance space for the front end of the inner cylinder 8 and the internal unloading ring 2. In terms of physical connection, the top pressure unit 1 and the intermediate cylinder 9 can be rigidly fixed by threaded connection, flange anchoring, or high-strength pin. This assembly structure allows the top pressure unit 1 to strictly follow the synchronous linear displacement of the intermediate cylinder 9 in the multi-stage cylinder in terms of kinematic characteristics, thereby transmitting the hydraulic thrust of the intermediate cylinder 9 to the external environment without loss.

[0060] During the system's cylinder tensioning operation, the establishment and mechanical transfer process of the reverse rigid support can be broken down into the following steps: The external high-pressure fluid drives the middle cylinder 9 to extend outward along the axis of the steel strand 15, and the top pressure device 1 assembled at the front end of the middle cylinder 9 gradually approaches the external J-type anchor 16. As the extension stroke increases, the front end face of the top pressure device 1 eventually flattens and abuts against the front end face of the J-type anchor 16, forming a mechanical contact interface between the two. Driven by the continuous oil supply from the hydraulic system, the middle cylinder 9 tends to extend forward. At this time, the fixed J-type anchor 16 applies an equal and opposite reaction force to the top pressure device 1 through the aforementioned end face abutment. Ultimately, the reaction force is transmitted backward along the cylinder wall of the top pressure device 1 to the pressure-bearing body of the actuator assembly 300, forming the basic mechanical support point when the multi-stage hydraulic cylinder pulls the steel strand 15 backward in macroscopic mechanics.

[0061] Relying on the rigid contact between the top pressure device 1 and the J-type anchor 16, the system converts the outward thrust of the central cylinder 9 into an effective tension force for pulling back the steel strand 15. Regarding the selection of wear-resistant materials for the contact surface of the top pressure device 1 and the end-face profile adaptation design to accommodate anchors of different specifications, those skilled in the art can make conventional selections based on the actual stress conditions of the project. Surface hardening treatment and geometric matching are well-known techniques in the field and will not be elaborated upon here.

[0062] To meet the operational requirements of continuous climbing without lifting, the actuator assembly 300 needs to establish a second mechanical fulcrum, distinct from the top pressure device 1, during the cylinder retraction phase. Therefore, a climbing handle 3 is provided on the front outer housing of the actuator assembly 300.

[0063] As a specific suspension fit structure, the main body of the lifting handle 3 typically adopts a symmetrical, segmented structure. In terms of spatial assembly, the root of the lifting handle 3 is pivotally connected to the outer shell of the actuator assembly 300, specifically the outer cylinder 10, via rotating components such as pins, achieving an openable and closable fit. To achieve mechanical restraint with the external anchor, the internal contour of the lifting handle 3 is machined with specific geometric grooves. The shape of these grooves is a bayonet structure adapted to the outer steps of the J-type anchor 16. Using this bayonet structure, the lifting handle 3 can be semi-enclosed or fully enclosed and fastened to the outer body of the J-type anchor 16 in the closed state.

[0064] During the alternating switching of mechanical fulcrums and the execution of step-by-step yielding, the establishment and translation of the suspension support are specifically manifested as follows: When the assembly 300 enters the retraction and anchoring stage, the climbing handle 3 is kept or adjusted to the closed state, so that the bayonet structure inside the climbing handle 3 is embedded and locked in the step part of the J-type anchor 16. Relying on the mutual interference between the bayonet structure and the step in the axial direction, the climbing handle 3 and the J-type anchor 16 form a mechanical limiting fit for the rearward movement of the actuator assembly 300. As the middle cylinder 9 retracts, the front top pressure device 1 gradually loses its thrust on the end face of the J-type anchor 16. At this time, the aforementioned mechanical limit mechanism takes over the overall weight of the execution assembly 300, providing stable step suspension support for the machine. Furthermore, using the suspension support as a fixed force reference, when the multi-stage hydraulic cylinder performs the internal retraction and return action, since the outer cylinder 10 and the climbing handle 3 are macroscopically mounted on the J-type anchor 16, the hydraulic cylinder assembly that releases the clamping mechanism and the related mechanism move in the opposite direction to the fixed housing. This macroscopically causes the overall housing of the execution assembly 300 to axially translate along the fixed steel strand 15 toward the J-type anchor 16.

[0065] From the perspective of overall kinematics, this alternating mechanical fulcrum switching design reliably switches the end-face thrust support during the cylinder ejection stage to the suspension load-bearing support during the retraction stage. Through the physical gripping of the J-shaped anchor 16 steps by the climbing handle 3, the actuator assembly 300, even when the internal locking mechanism is disengaged from the steel strand 15, can largely avoid slipping or falling backward along the steel strand 15 due to its own weight. Regarding the specific opening and closing locking mechanism design of the climbing handle 3 and the strength verification of the hinge pin, those skilled in the art can perform conventional matching based on the total weight of the machine. The locking device and material selection are well-known technologies in the field and will not be elaborated upon here.

[0066] Before initiating the dynamic tensioning cycle, the automatic continuous anchor cable tensioning system needs to undergo an initial physical assembly and positioning phase. This initial phase aims to establish stable boundary constraints for subsequent hydraulic force transmission and the relative motion of the multi-stage cylinders.

[0067] To achieve the initial docking of the actuator assembly 300 with the operating environment, the initial mechanical limit locking process of the system may specifically include: In the absence of pressure buildup or pre-set cable threading conditions, the internal unloading ring 2 controls the push of the return spring to hold the tool anchor 5 in place, keeping the multi-lobed wedges in a radially open state. Subsequently, the operator sequentially inserts the end of the steel strand 15 extending from the roof or rock mass into the central channel of the front end of the actuator 300, the pressure device 1, the internal multi-stage hydraulic cylinder, and the displacement interference type locking and unloading mechanism, completing the basic cable threading and initial centering positioning of the machine. Then, the actuator assembly 300 is pushed along the axis of the steel strand 15, so that the whole assembly moves toward the J-type anchor 16 fixed at the orifice, until the structure at the front end of the actuator assembly 300 is close to the anchor. Then, the climbing handle 3, which is externally pivotally connected to the closing actuator assembly 300, is operated so that the pre-machined geometric bayonet structure inside the climbing handle 3 is embedded and locked in the step area around the J-type anchor 16. Thus, relying on the rigid interference fit between the bayonet structure and the step part in the axial direction, the overall shell of the actuator 300 is suspended on the J-type anchor 16, thereby completing the initial limiting fixation and self-weight bearing of the actuator 300 on the steel strand 15.

[0068] As a supplementary explanation of technical details, the aforementioned initial mechanical limit locking not only solves the physical support problem of the equipment before heavy-load tensioning, but also provides a force benchmark for the pressure build-up of the internal fluid. After the climbing handle 3 is closed, the external structure of the actuator assembly 300 and the J-type anchor 16 form a relatively static macroscopic constraint system. It should be noted that since the external power oil source 100 has not yet started supplying oil to build up pressure, the locking mechanism inside the actuator assembly 300 has not yet undergone displacement interference linkage for tensioning, and the internal tool anchor 5 and steel strand 15 usually maintain a relatively sliding physical gap. This initial spatial layout reserves the necessary free stroke for the subsequent multi-stage cylinder assembly to generate extension displacement under hydraulic drive and to trigger the internal wedge clamping action.

[0069] After initial positioning is completed, the system enters its core working state. This stage aims to convert the energy of the hydraulic fluid into effective mechanical tension on the steel strand 15.

[0070] To achieve the force-driven elongation of the steel strand 15, the system's cylinder top compression and axial pulling process can specifically include: Release the external forced interference applied to the anchor ring 2 during the initial cable-threading stage, restoring the free movement state of the internal mechanical linkage of the multi-stage hydraulic cylinder assembly. Subsequently, operate the multi-way reversing valve of the external power oil source 100 to keep the system in a continuous oil supply state; High-pressure hydraulic oil is guided into the rodless chamber inside the multi-stage cylinder assembly. Under the action of fluid pressure, the middle cylinder 9 inside the actuator 300 begins to overcome resistance and extend axially along the steel strand 15. As the middle cylinder 9 extends, the top pressure device 1 fixed at its front end gradually fits against the end face of the J-type anchor 16, thereby forming a reverse rigid support point based on the J-type anchor 16. As the middle cylinder 9 extends, due to the change in relative displacement, the unloading ring 2 moves forward and disengages from the limit on the tool anchor 5. Under the linkage of the return spring and the wedge effect, the internal locking mechanism quickly and radially clamps the steel strand 15 passing through the central hole. Then, when the internal locking mechanism completes clamping and the top pressure device 1 provides stable support, the actuator 300 uses hydraulic thrust to drive the locking mechanism and the clamped steel strand 15 to move backward as a whole, thereby applying a set axial tension force to the steel strand 15 until the middle cylinder 9 reaches the maximum extension stroke or the hydraulic system reaches the set target working pressure threshold, and the single cylinder extension tension stroke ends.

[0071] Under this operating condition, the above steps are a mechanical linkage process that occurs simultaneously with the expansion of the hydraulic chamber volume. The establishment of the support point and the clamping of the internal mechanism are completed synchronously within a very short stroke. This linkage logic allows the system to achieve a stable output of external pulling force without the need for an additional clamping control oil circuit, relying solely on the oil inlet command of a single fluid pipeline. Regarding the specific structure of the multi-way directional valve in the external power oil source 100 and the corresponding hydraulic circuit overpressure overflow prevention design, those skilled in the art can make conventional selections based on standard explosion-proof requirements for underground coal mines, etc. The valve group setup and safety protection are well-known technologies in this field and will not be elaborated upon here.

[0072] After a single tensioning stroke is completed, the system needs to release the clamp on the steel strand 15 and allow the equipment itself to retract and shift to reserve stroke space for the next tensioning cycle.

[0073] To achieve the reset of the internal components of the machine and the relative translation of the whole, the system's retraction and anchor release and step translation process can specifically include: The hydraulic logic control assembly 200 responds to stroke completion or pressure threshold signals by switching the direction of hydraulic fluid. At this time, the rod chamber in the multi-stage cylinder assembly receives oil and builds pressure, while the rodless chamber releases pressure to the low-pressure return line. Under the reverse drive of the hydraulic pressure in the rod chamber, the intermediate cylinder 9 inside the actuator assembly 300 begins to retract. As a result, the top pressure device 1, which was originally against the J-type anchor 16 during the cylinder exit phase, gradually loses its thrust support; With the failure of the top support, the closed climbing handle 3 and the stepped part of the J-type anchor 16, which is engaged, rigidly interfere with each other. As an alternating bearing design, this fit takes over the physical weight of the actuator assembly 300, providing a suspension stress point for the system; As the middle cylinder 9 retracts relative to the inner cylinder 8, the unloading ring 2, which moves with the middle cylinder 9, pushes back against the tool anchor 5. As the displacement difference accumulates, the mechanical thrust generated by the unloading ring 2 overcomes the effect of the return spring, forcibly pushing the tool anchor 5 out of the conical hole area, thereby releasing its radial clamping on the steel strand 15; After the clamping constraint of the steel strand 15 is released, the multi-stage cylinder assembly continues to perform the internal retraction action. From a relative kinematics perspective, since the steel strand 15 has been pulled outward during the previous tensioning stage, the outer climbing handle 3 is now attached to the J-type anchor 16, keeping the overall shell spatially fixed. The internal cylinder 9 and the reset tool anchor 5 slide inward along the steel strand 15. Macroscopically, this is equivalent to the actuator assembly 300 swallowing a new length of steel strand 15, achieving axial stepping translation along the steel strand 15 towards the working surface, i.e., forward.

[0074] The aforementioned retraction and anchor loosening operation demonstrates the coordination between the mechanical fulcrum conversion and the internal mechanical linkage. During the retraction stroke, the system utilizes the reverse movement of the same set of cylinders to simultaneously complete the forced disengagement of the tool anchor 5 and its stepping displacement relative to the steel strand 15. This yielding method reduces the frequency of manual disassembly of the clamping plates, removal of the cylinders, and repositioning. Regarding the specific selection of the limit switches or pressure relays used to trigger commutation within the hydraulic logic control assembly 200 and the electro-hydraulic control wiring, those skilled in the art can perform conventional settings based on the system's level of automation. The automated logic triggering and circuit construction are well-known technologies in this field and will not be elaborated upon here.

[0075] By combining and switching between two basic working conditions—cylinder extension and retraction—the automatic continuous tensioning system for anchor cables can, to some extent, compensate for the single-stroke limitation of multi-stage hydraulic cylinder components in terms of physical structure, thereby achieving continuous operation without slinging at the macroscopic operation level.

[0076] As a specific system operation mechanism, the dynamic coordination process of fulcrum alternation and cyclical ascent can be decomposed into the following steps: The external power oil source 100 maintains a continuous fluid output state, and the hydraulic logic control assembly 200 periodically changes the pipeline direction of the high-pressure fluid entering the execution assembly 300 according to the internally set reversing logic triggering conditions. Under the tensioning condition, the system uses the top pressure device 1 to abut against the end face of the J-type anchor 16 to form the first rigid force support point. The internal components complete the clamping of the steel strand 15 and rely on this support point to perform axial stretching outward. As a key component in the system's cyclic operation, the J-type anchor 16 at the orifice is typically equipped with a one-way locking device, such as a working clamp, during the retraction stepping condition. When the actuator assembly 300 prepares to release the steel strand 15, the J-type anchor 16 can lock the stretched steel strand 15 to prevent it from rebounding due to internal stress. Based on this force boundary, the system switches the load-bearing and positioning reference to the second suspension limit fulcrum formed by the climbing handle 3 and the step of the J-type anchor 16. Under the interference of the anchor retraction, the internal components release the steel strand 15 and slide inward along the stretched and fixed steel strand 15. Finally, with the continuous reversal of the hydraulic fluid, the first rigid force support and the second suspension limit support alternately bear the system load between the two working stages, and the execution assembly 300 performs the superimposed action of clamping and pulling and releasing and sliding on the steel strand 15 in a cycle.

[0077] Based on the physical constraint design of alternating fulcrum switching, during the return phase when the execution assembly 300 loses the support of the first force-bearing fulcrum, it relies on the replacement of the second suspension fulcrum, reducing the risk of leaving the existing working position. This mechanical mechanism of displacement superposition through alternating support transforms the short-stroke discrete action of a single hydraulic cylinder into a continuous stepping displacement of the entire equipment along the steel strand 15 towards the working surface in a time sequence.

[0078] By repeatedly cycling within a local space, the system gradually accumulates the macroscopic tensile length, thereby helping to meet the continuous requirements of deep-hole or high-stress anchor cable tensioning operations. Regarding the specific valve control cycle controlling the fluid alternation frequency in the hydraulic logic control assembly 200, and the internal flow channel arrangement of various hydraulic control elements used to set trigger thresholds, those skilled in the art can perform conventional matching based on the expected total tensile allowance of the actual steel strand 15 and the pump station displacement. The setting of its cycle control parameters and the valve body integration design are well-known technologies in the field and will not be elaborated upon here.

Claims

1. An anchor cable continuous tensioning jack, characterized by, include: A multi-stage hydraulic cylinder assembly, comprising an inner cylinder (8), a middle cylinder (9), and an outer cylinder (10) arranged in a coaxial sleeve layout, wherein an oil port communicating with the internal chamber of the multi-stage hydraulic cylinder assembly is provided on the side wall of the outer cylinder (10). The tool anchor (5) housed inside the inner cylinder (8) and the return spring that applies axial thrust to the tool anchor (5) are connected to the middle cylinder (9) with an anchor removal ring (2) extending into the inner cylinder (8). The linear displacement of the middle cylinder (9) relative to the inner cylinder (8) changes the mechanical contact state between the anchor removal ring (2) and the tool anchor (5), thereby achieving the clamping and loosening of the steel strand (15) passing through the central hole. The top pressure device (1) is fixed to the front end of the middle cylinder (9), and the climbing handle (3) is pivotally connected to the external structure of the outer cylinder (10).

2. The anchor cable continuous tensioning jack according to claim 1, characterized in that, A sliding guide structure with clearance fit is formed between the outer side wall of the inner cylinder (8) and the inner side wall of the middle cylinder (9), and between the outer side wall of the middle cylinder (9) and the inner side wall of the outer cylinder (10). The pressure-bearing structure of the middle cylinder (9) cooperates with the inner cylinder (8) and the outer cylinder (10) to divide the overall enclosed space inside the multi-stage cylinder assembly into a rodless chamber and a rod chamber. The oil port includes an outlet oil port (12) that connects to the rodless chamber and a return oil port (13) that connects to the rod chamber.

3. The anchor cable continuous tensioning jack according to claim 1, characterized in that, An anchor cup (4) and a spring seat (6) are also coaxially installed inside the inner cylinder (8); The inner wall of the anchor cup (4) is machined with a conical hole, and the tool anchor (5) is slidably accommodated in the conical hole of the anchor cup (4); The main body of the spring seat (6) is fixedly assembled in the inner hole at the rear end of the inner cylinder (8), and the reset spring is housed inside the spring seat (6) and abuts against the rear end face of the tool anchor (5). The unloading ring (2) is arranged in front of the tool anchor (5).

4. The anchor cable continuous tensioning jack according to claim 3, characterized in that, When the middle cylinder (9) moves forward in a linear displacement relative to the inner cylinder (8), the unloading ring (2) disengages from the mechanical contact with the tool anchor (5), and the reset spring releases its elastic potential energy to continuously push the tool anchor (5) to slide forward along the inner conical surface of the anchor cup (4), forcing the tool anchor (5) to generate radial contraction displacement inward, and initially gripping the steel strand (15) passing through the central hole. When the middle cylinder (9) retracts relative to the inner cylinder (8), the rear end face of the unloading ring (2) abuts against and overcomes the axial thrust of the reset spring, forcibly pushing the tool anchor (5) out of the tight conical hole area at the front end of the anchor cup (4), thereby releasing the radial rigid constraint imposed by the anchor cup (4) on the outside.

5. The anchor cable continuous tensioning jack according to claim 3, characterized in that, The outer wall cone angle of the tool anchor (5) is set to be smaller than the equivalent friction angle between the contact surface of the tool anchor (5) and the anchor cup (4), forming a friction self-locking constraint mechanism to prevent the tool anchor (5) from slipping backward inside the anchor cup (4).

6. The anchor cable continuous tensioning jack according to claim 1, characterized in that, The top pressure device (1) is a hollow tubular or sleeve-shaped structure, and a through hole is provided in the center of the top pressure device (1) for the steel strand (15) to pass through without interference. The internal contour of the climbing handle (3) is machined with a geometric groove, which is a bayonet structure adapted to the outer steps of the external J-type anchor (16).

7. The anchor cable continuous tensioning jack according to claim 6, characterized in that, The main body of the climbing handle (3) adopts a symmetrical split structure, and the root of the climbing handle (3) is pivotally connected to be opened and closed through a rotating component.

8. A step-climbing method for a continuous anchor cable tensioning jack, characterized in that, The application of the anchor cable continuous tensioning jack as described in claims 1-7 includes the following alternating cyclic steps: Under the tensioning condition of cylinder release, the multi-stage hydraulic cylinder assembly performs an extension action, using the top pressure device (1) to abut against the end face of the external J-type anchor (16) to form a first rigid force support point, the internal assembly completes the clamping of the steel strand (15), and performs axial extension outward based on the first rigid force support point; In the retraction stepping condition, the multi-stage hydraulic cylinder assembly performs a retraction action, and the second suspension limiting support point formed by the climbing handle (3) and the step of the J-type anchor (16) takes over the load. Under the interference of the anchor retraction, the internal component releases the steel strand (15) and slides inward along the stretched and fixed steel strand (15), causing the overall shell to move axially towards the J-type anchor (16) along the fixed steel strand (15).

9. The step-climbing method for a continuous anchor cable tensioning jack according to claim 8, characterized in that, The aforementioned conditions under cylinder tensioning specifically include: High-pressure hydraulic oil is guided into the rodless chamber inside the multi-stage cylinder assembly. Under the action of fluid pressure, the middle cylinder (9) is driven to overcome resistance and extend axially along the steel strand (15). The top pressure device (1) fixed at its front end is attached to the end face of the J-type anchor (16). As the middle cylinder (9) extends, the unloading ring (2) moves forward and disengages from the limit on the tool anchor (5). The internal locking mechanism quickly and radially clamps the steel strand (15) passing through the central hole. Based on this fulcrum, the jack drives the locking mechanism and the clamped steel strand (15) to move backward as a whole, applying axial tension to the steel strand (15).

10. The step-climbing method for a continuous anchor cable tensioning jack according to claim 8, characterized in that, The retraction step operation specifically includes: Under the reverse drive of the hydraulic pressure in the rod chamber, the middle cylinder (9) is driven to retract, the top pressure device (1) loses its thrust support, and the climbing handle (3) in the closed state and the step part of the J-type anchor (16) rigidly interfere to take over the load. The unloading ring (2) that moves with the middle cylinder (9) moves backward against the tool anchor (5), and the mechanical thrust generated overcomes the effect of the return spring, forcibly pushing the tool anchor (5) out of the cone hole area and releasing the radial clamping of the steel strand (15); The climbing handle (3) is attached to the J-type anchor (16) so that the overall shell is kept in space and the internal cylinder (9) and the reset tool anchor (5) slide inward along the steel strand (15).

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