A traction elevator car guide rail safety braking system

Abstract

The present invention discloses a safety braking system for a traction elevator car guide rail, which includes a speed limiter and a safety clamp having main and driven shafts. The safety clamp includes a base, a clamp body, and an elastic positioning device. The speed limiter is associated with the safety clamp. A stop block is provided on the clamp body. There are two inner wedges on the left and right inside the clamp body, and an outer wedge is provided outside the inner wedge. The base is provided with a limiting mechanism for limiting the positions of the inner and outer wedges. The elastic positioning device makes the large ends of the inner and outer wedges move away from each other in the up and down directions, and the limiting mechanism limits the inner and outer wedges in the initial position in the up and down directions. When the rotational speed of the driving shaft reaches the rated rotational speed, the driving shaft is engaged with the driven shaft through a centrifugal clutch structure, and then drives the clamp body to move. The stop block on the clamp body makes the large ends of the inner and outer wedges approach each other, so that the two inner wedges approach each other and enter the braking state. The present invention can achieve two-way progressive braking for the car, thereby ensuring high safety of the car.

Description

Technical Field

[0001] The present invention relates to the technical field of braking systems for traction elevators, and more particularly to a safety braking system for a car guide rail of a traction elevator. Background Art

[0002] In a traction elevator, a safety braking system is a safety device that must be installed compulsorily. The existing safety braking system includes a speed limiter for sensing the running speed of the car and a braking device for forcibly braking the elevator when the car moves at an excessive speed. The speed limiter usually includes a driving shaft on which a pulley is provided, and a steel wire rope for towing the car is wound around the pulley. When the car ascends or descends, the steel wire rope drives the driving shaft to rotate through the pulley; when the car ascends or descends at an excessive speed, the speed limiter senses the rotation speed of the driving shaft and acts, thereby driving the braking device to act to brake the car, and thus ensuring the safety of the elevator. In the national safety standard of the elevator, it is stipulated that when the running speed of the car exceeds 115% of the rated speed, the speed limiter should start, thereby driving the braking device to brake the car or the counterweight. The braking device is divided into two types: car braking and counterweight braking, which can be used separately or simultaneously according to different safety requirements. When the car moves at an excessive speed on the guide rail, the braking device for braking the car generates frictional force by clamping the guide rail to brake the car. The braking device for braking the counterweight generates frictional force by clamping the steel wire rope connecting the counterweight to brake the counterweight, and thus realizes the braking of the car.

[0003] Since a great impact will be generated on the car during emergency braking, and in severe cases, the passengers in the car may be injured. For this reason, some safety braking systems with a buffering effect have been invented. For example, a "progressive centrifugal brake" disclosed in a Chinese patent document, with a publication number of CN107089610A, specifically includes a rotating shaft and a braking mechanism sleeved on the rotating shaft. The braking mechanism includes a flyweight, a brake disc, and a guide tube. The guide tube is sleeved on the outer wall of the rotating shaft, and the front end of the rotating shaft extends out of the guide tube and is correspondingly equipped with a flyweight: the brake disc is a cylindrical body, the rear end of which is assembled on the outer wall of the guide tube by threads, and the front end extends in front of the rotating shaft. The flyweight is displaced towards the inner wall of the brake disc by centrifugal force. The inner wall of the brake disc is provided with ratchet teeth corresponding to the flyweight, and the outer wall of the guide tube is provided with an elastic buffer member that abuts against the brake disc. The flyweight is thrown out by centrifugal force, and the thrown flyweight engages with the brake disc. The brake disc is driven by the rotating shaft to displace along the guide tube and compress the buffer spring, thereby forming a progressive braking, reducing the impact and damage on the car and the transmission part during instantaneous braking, and avoiding the discomfort of the passengers in the elevator.

[0004] The above-mentioned brake sets the speed limiter and the braking device together and has a buffering effect during braking. However, this brake has the following defects: First, this brake can only initiate safety braking for overspeed rotation in one direction. That is to say, we need to set at least two sets of brakes to separately achieve safety braking for the overspeed upward movement (topping) and overspeed downward movement (bottoming) of the car. Second, this brake does not directly clamp and brake the guide rail supporting the car or the steel wire rope towing the car, but brakes the driving shaft. Therefore, it is ultimately the friction between the steel wire rope and the pulley that brakes the car. This braking method is the same in principle as the inherent braking method of the elevator, which brakes the traction machine and then relies on the friction between the steel wire rope and the traction wheel to achieve the braking of the car. Such a braking method has problems such as small braking force and serious damage to the steel wire rope and the pulley after emergency braking.

[0005] In particular, since the existing elevator car braking system directly performs emergency braking with the maximum braking friction, resulting in an emergency braking effect, during braking, the car guide rail and the braking device will be severely damaged due to excessive braking friction. That is to say, it is difficult for the existing elevator braking system to effectively monitor and control its actual performance and state. People usually simply test whether the speed limiter will operate when the elevator is overspeed and whether the brake blocks in the safety clamp can be lifted as a means and basis for judging whether the braking system is normal, and cannot judge the state of the braking system through real braking data. Summary of the Invention

[0006] An object of the present invention is to solve the problem that the existing elevator safety braking system cannot achieve two-way deceleration braking for a car moving at a speed deviating from the normal lifting speed, and to provide a safety braking system for the guide rail of a traction elevator car, which can effectively achieve two-way braking for a car moving at a speed deviating from the normal moving speed, thereby ensuring a high safety level of the car and simplifying the structure of the braking system.

[0007] Another object of the present invention is to solve the problem that the existing elevator safety braking system cannot perform a braking process test in a real scenario to evaluate the reliability of the system, and to provide a safety braking system for the guide rail of a traction elevator car, which can simulate a real braking scenario to perform simulation detection on the braking system, thereby ensuring its safety and reliability, and at the same time making an assessment of the state and service life of the braking system through recording, comparison and analysis of the detection data.

[0008] To achieve the above objects, the present invention adopts the following technical solutions:

[0009] A safety braking system for a traction elevator car guide rail, comprising an interrelated speed governor and safety tongs. The speed governor includes a frame, a driving shaft, a driven shaft coaxially arranged on the frame, and a damping spring for restricting the rotation of the driven shaft. The steel wire rope of the traction car bypasses a pulley arranged on the driving shaft, and a centrifugal clutch structure is provided between the driven shaft and the driving shaft. The safety tongs include a base, a tong body movably arranged on the base, and an elastic positioning device. At least two upper and lower stoppers are provided on the tong body. Two left and right inner wedges are movably arranged in the tong body. The opposite planes of the inner wedges are braking surfaces for braking. The outer sides of the inner wedges away from each other are inwardly inclined inner driving inclined surfaces. The inner driving inclined surfaces of the two inner wedges are arranged in a V-shaped pattern. A movable outer wedge is provided outside the inner wedges. The inner side surface of the outer wedge is an outer driving inclined surface for cooperating with the inner driving inclined surface. A limiting mechanism for defining the positions of the inner wedges and the outer wedge is provided on the base. The elastic positioning device makes the inner driving inclined surfaces of the inner wedges and the outer driving inclined surfaces of the outer wedges approach each other, and the large ends of the inner wedges and the large ends of the outer wedges are separated from each other in the up and down directions. The limiting mechanism limits the inner and outer wedges in the up and down directions to the initial position, and at this time, the distance between the braking surfaces of the two inner wedges is the largest. When the rotational speed of the driving shaft reaches the rated rotational speed, the centrifugal clutch structure engages the driving shaft and the driven shaft, and the speed governor drives the tong body to move in the up and down directions through an associated mechanism. The stoppers on the tong body make the large ends of the inner and outer wedges approach each other in the up and down directions, so that the two inner wedges approach each other and enter the braking state.

[0010] The safety braking system of the present invention is provided at the guide rail of the car, and specifically includes a speed limiter for detecting the moving speed of the car and a safety clamp for decelerating and braking the car. The safety clamp includes two inner wedges and two outer wedges on the left and right. A braking surface for clamping the guide rail of the car is provided on the opposite side of the two inner wedges. When the car moves up and down, the wire rope can drive the pulley to rotate forward and backward. When the braking surfaces of the two inner wedges clamp the guide rail of the car, the braking of the car can be achieved. Since the large ends of the inner and outer wedges of the present invention are respectively located on the upper and lower sides, and the elastic positioning device makes the inner driving inclined surface of the inner wedge and the outer driving inclined surface of the outer wedge approach each other. Therefore, under the action of the inner and outer driving inclined surfaces, the inner and outer wedges move towards their respective large end sides and move away from each other in the up and down direction. At this time, the limiting mechanism limits the inner and outer wedges in an initial position where they are separated from each other in the up and down direction. As we know, since the inner and outer driving inclined surfaces are in contact with each other, when the inner wedge moves along the outer driving inclined surface of the outer wedge, on the one hand, there will be a longitudinal movement in the up and down direction, and on the other hand, there will be a lateral movement in the left and right direction. When the car moves up and down at a normal speed, the driving shaft and the driven shaft in the speed limiter are separated, so the safety clamp does not act. When a fault occurs in the elevator and the car moves up and down rapidly, the driving shaft rotates rapidly accordingly. At this time, the centrifugal clutch structure can connect the driven shaft and the driving shaft under the action of centrifugal force, thereby driving the driven shaft to rotate. The speed limiter moves the clamp body up or down through the associated mechanism. In this way, the block on the clamp body can drive the inner wedge to move closer to the outer wedge, or drive the outer wedge to move closer to the inner wedge. Under the action of the mutually contacting inner and outer driving inclined surfaces, the two inner wedges move horizontally inward and approach each other to clamp the guide rail of the car, thereby achieving the two-way braking of the car. That is to say, a set of mechanisms of the present invention can simultaneously achieve the two-way braking of the car, which can avoid safety failures such as the car hitting the top and squatting at the bottom, and is beneficial to simplifying the structure of the braking system. It should be noted that in the existing wedge-type braking device, since the acting force for driving the braking wedge is not continuous, that is, when the braking wedge starts to brake under the pulling action, the braking wedge maintains its position in the braking position by the self-locking action formed by its smaller inclination angle. Therefore, when the size or error of the guide rail of the car changes, the braking friction force will change accordingly, thereby affecting the braking performance and effect, and causing difficulties in resetting the braking wedge in the self-locking state during subsequent maintenance. In the whole braking process of the present invention, the wire rope will always drive the clamp body to maintain the braking position through the associated mechanism. That is to say, in the whole braking process, the inner wedge or the outer wedge will always be subjected to a pulling force. Therefore, we can make the inner and outer wedges have a larger inclination angle, so as to avoid the self-locking phenomenon of the inner and outer wedges during braking. During subsequent maintenance, we only need to move the car in the reverse direction to easily unlock and reset the braking device.In particular, when braking, the damping spring causes the driving force output to the safety clamp to gradually increase, and the frictional braking force formed by the safety clamp gradually increases, thereby effectively avoiding the phenomenon of sudden braking and damage to the car guide rail and braking device during braking. Therefore, it is possible to simulate the detection of the braking system under a real braking scenario, effectively improving the safety and reliability of the system.

[0011] Preferably, the centrifugal clutch structure includes a speed-regulating spring, a hammer and a spring seat that are radially slidably arranged on the end face of the pulley, and a limiting block connected to the driven shaft. An articulated connecting rod is provided between the hammer and the spring seat. The speed-regulating spring positions the spring seat at an initial position away from the driving shaft. The spring seat makes the hammer in an initial position close to the driving shaft through the articulated connecting rod. At this time, the driving shaft and the driven shaft are in a separated state. When the rotational speed of the driving shaft reaches the rated speed, the centrifugal force causes the hammer to radially move outwards to a terminal position away from the driving shaft. The hammer makes the spring seat radially move inwards to a terminal position close to the driving shaft through the articulated connecting rod. The outer end of the hammer abuts against the limiting block, and the driven shaft and the driving shaft are in an engaged state.

[0012] The driving shaft can be easily associated with the car through the pulley and the steel wire rope wound around the pulley, so that a simple linear relationship can be formed between the rotational speed of the driving shaft and the lifting speed of the car. It can be understood that we can set a radial T-shaped groove or dovetail groove on the end face of the pulley, so that the hammer and the spring seat can radially move along the T-shaped groove or dovetail groove. Since an articulated connecting rod is provided between the hammer and the spring seat, the hammer and the spring seat can form a linkage. When the hammer moves outwards, the spring seat moves inwards, and vice versa, when the spring seat moves outwards, the hammer moves inwards. The speed-regulating spring drives the spring seat to move outwards, so that the spring seat is positioned at the initial position on the outside. Correspondingly, at this time, the spring seat makes the hammer positioned at the initial position on the inside through the articulated connecting rod. At this time, the driven shaft and the driving shaft are in a separated state. When the pulley rotates, the hammer on the end face of the pulley is subjected to a centrifugal force and moves outwards. At this time, the hammer drives the spring seat to move inwards against the elastic force of the speed-regulating spring through the articulated connecting rod. When the rotational speed of the pulley and the driving shaft reaches the rated speed, the centrifugal force causes the hammer to radially move outwards to a terminal position away from the driving shaft. At this time, the hammer makes the spring seat radially move inwards to a terminal position close to the driving shaft through the articulated connecting rod. The outer end of the rotating hammer can abut against the limiting block provided on the driven shaft. At this time, the driven shaft and the driving shaft are in an engaged state. The driven shaft rotates together with the driving shaft, and the resistance of the steel wire rope is increased by the driven shaft. Correspondingly, the pulling force of the steel wire rope driving the safety clamp is increased through the associated mechanism to achieve the deceleration braking of the car. It can be understood that we can conveniently adjust the rated speed of the driving shaft and the moving speed of the hammer, and further adjust the deceleration braking performance of the car by reasonably setting parameters such as the elastic coefficient and pre-tightening elastic force of the speed-regulating spring.

[0013] Preferably, both sides of the outer end of the hammer away from the driving shaft are first inclined surfaces, so that the outer end of the hammer forms a lap joint end in the shape of a dovetail with a larger outer part and a smaller inner part. A lap joint sleeve is provided at one end of the driven shaft close to the driving shaft, and the limiting block is provided on the inner side wall of the lap joint sleeve. Both sides of the limiting block are second inclined surfaces adapted to the first inclined surfaces, so that the limiting block is in the shape of a dovetail.

[0014] The outer end of the hammer of the present invention is provided with a lap joint section in the shape of a dovetail. Correspondingly, the limiting block is also in the shape of a dovetail. In this way, when the hammer extends outwards, the first inclined surface of the lap joint section in the shape of a dovetail can abut against the second inclined surface of the limiting block, so that the driven shaft is engaged with the driving shaft. At this time, the lap joint section and the limiting block form an inverted hook structure, which can avoid the retraction of the hammer caused by the decrease in the rotational speed, and further realize the complete braking of the car.

[0015] Preferably, a limiting sleeve is fixedly connected to the frame. The driven shaft extends into the limiting sleeve. The damping spring is a braking coil spring sleeved on the part of the driven shaft extending into the limiting sleeve. One end of the braking coil spring is fixedly connected to the frame, and the other end of the braking coil spring is fixedly connected to the driven shaft.

[0016] When the driving shaft drives the driven shaft to rotate forward, the braking coil spring gradually tightens until the braking coil spring is tightly wound around the driven shaft. At this time, the driven shaft stops rotating. Correspondingly, the driving shaft and the pulley stop rotating, so that the tension of the steel wire rope wound around the pulley of the driving shaft gradually increases until the pulley stops rotating. At this time, the steel wire rope and the pulley form dynamic friction to generate the maximum tension. When the driving shaft drives the driven shaft to rotate reversely, the braking coil spring gradually relaxes until the braking coil spring is tightly attached to the inner side wall of the limiting sleeve. At this time, the driven shaft stops rotating. Correspondingly, the driving shaft and the pulley stop rotating, so that the tension of the steel wire rope wound around the pulley of the driving shaft gradually increases until the pulley stops rotating. At this time, the steel wire rope and the pulley form dynamic friction to generate the maximum tension. That is to say, the braking friction force of the inner wedge block generated by the tension of the steel wire rope gradually increases from zero. It can be understood that, compared with other forms of springs, the braking coil spring has a larger rotational contraction amount. On the one hand, it can significantly reduce the external dimension of the reducer, and at the same time, it can effectively improve the buffering effect during braking, avoid damaging the car guide rail, and further realize the detection of the braking system in the simulated real scene to ensure the safety, effectiveness and reliability of the braking system.

[0017] Preferably, the associated mechanism includes a driving swing arm and a driving slider provided on the clamp body. One end of the driving swing arm is hinged to the driving slider, and a driving shaft rotatably connected to the machine base is provided at the other end of the driving swing arm. The tension of the steel wire rope drives the driving swing arm to swing through the driving shaft, and then drives the clamp body to move in the up and down direction through the driving slider.

[0018] The driving swing arm can conveniently drive the driving slider to move, and further drive the clamping body to move up and down.

[0019] Preferably, two vertical rectangular insertion holes are coaxially provided on the base. Guide bars are fitted in the rectangular insertion holes. At one end of the two guide bars close to each other, there are horizontal sliding bars. The two sliding bars respectively abut against the upper and lower sides of the hinge shaft of the driving swing arm and the driving slider. A clamping body return spring is sleeved on the guide bar.

[0020] The sliding bar and the guide bar intersect to form a T shape, and the guide bar is fitted in the rectangular insertion hole, so the rotation of the sliding bar and the guide bar can be avoided. The two clamping body return springs can position the hinge shaft of the driving swing arm and the driving slider at the middle position through the sliding bar, and further make the clamping body elastically in the initial middle position through the driving slider. When the driven shaft drives the driving slider to move through the swing of the driving swing arm and further drives the clamping body to move up and down, the hinge shaft of the driving swing arm and the driving slider can move horizontally between the two upper and lower sliding bars, avoiding jamming.

[0021] Preferably, square clamping holes are respectively provided on the upper and lower sides of the base. A clamping sleeve with the rectangular insertion hole is arranged in the clamping hole. The guide bar is fitted in the rectangular insertion hole of the corresponding clamping sleeve on one side. A shoulder protruding outward is provided in the middle of the outer side surface of the clamping sleeve. The outer side wall of the part of the clamping sleeve located outside the shoulder is a regular quadrangular prism surface adapted to the corresponding clamping hole. Two adjusting nuts are threadedly connected to the outer side wall of the part of the clamping sleeve located inside the shoulder. One end of the clamping body return spring abuts against the sliding bar on the corresponding side, and the other end is sleeved on the clamping sleeve on the corresponding side and abuts against the adjusting nut. Transition cylindrical surfaces are provided at the four corners of the regular quadrangular prism surface, and external threads are provided on the transition cylindrical surfaces. A locking nut is threadedly connected to the outer end of the clamping sleeve extending out of the clamping hole.

[0022] Since the outer side wall of the part of the clamping sleeve located outside the shoulder is a regular quadrangular prism surface adapted to the corresponding clamping hole, the rotation of the clamping sleeve can be effectively avoided. In particular, in the present invention, transition cylindrical surfaces are provided at the four corners of the regular quadrangular prism surface. Correspondingly, we can set corresponding rounded corners at the corners of the square clamping hole of the base, so as to facilitate the processing of the clamping hole and at the same time facilitate the locking nut to fix the clamping sleeve on the base. By changing the position of the adjusting nut on the clamping sleeve, we can conveniently adjust the pre-tightening force of the clamping body return spring, so as to ensure that the clamping body is accurately positioned at the initial middle position.

[0023] Preferably, the limiting mechanism includes two upper and lower positioning cards disposed on the left side of the front surface of the base, and two upper and lower positioning cards disposed on the right side of the front surface of the base. A sliding space for accommodating the inner and outer wedges is formed between the two upper and lower positioning cards. When the inner and outer wedges are in the initial position in the up and down direction, the upper positioning card abuts against the end surface of the large end of the outer wedge on the corresponding side, and the lower positioning card abuts against the end surface of the large end of the inner wedge on the corresponding side.

[0024] The two upper and lower positioning cards can conveniently define the initial position of the inner and outer wedges in the up and down direction, and the lower positioning card abuts against the end surface of the large end of the inner wedge on the corresponding side. Therefore, when the pliers body pushes down the outer wedge to move the inner wedge inward, the inner wedge can be prevented from separating from the positioning card.

[0025] Preferably, two of the above-mentioned stoppers are provided on the upper part of the pliers body, and two of the above-mentioned stoppers are provided on the lower part of the pliers body. A sliding groove is provided in the middle of the stopper, and the positioning card is slidably located in the corresponding sliding groove. When the pliers body moves upward, the stopper on the lower part of the pliers body drives upward to abut against the inner wedge of the positioning card at the lower part of the base, and the inner and outer wedges approach each other in the up and down direction, and the two inner wedges approach each other and enter the braking state; when the pliers body moves downward, the stopper on the upper part of the pliers body drives downward to abut against the outer wedge of the positioning card at the upper part of the base, and the inner and outer wedges approach each other in the up and down direction, and the two inner wedges approach each other and enter the braking state.

[0026] Since the positioning card on the base is slidably located in the corresponding sliding groove on the pliers body, the pliers body and the base form a reliable sliding connection, enabling the pliers body to move up and down relative to the base. At the same time, the stopper is divided into left and right parts by the sliding groove and the positioning card fitted in the sliding groove. Therefore, when the pliers body moves up and down, it can ensure sufficient contact area with the inner wedge or the outer wedge, and further enable the inner and outer wedges to approach each other in the up and down direction to clamp the car guide rail. It can be understood that the lower side of the upper stopper should be flush with the lower side of the upper positioning card, and correspondingly, the upper side of the lower stopper should be flush with the upper side of the lower positioning card. In this way, when starting to move the pliers body, the inner and outer wedges can approach each other in the up and down direction, and then the inner wedge moves inward to clamp the car guide rail.

[0027] Preferably, an electromagnet is provided at one end of the rack near the active shaft and away from the driven shaft. A sliding jack is provided inside the active shaft. An armature column driven by the electromagnet and having a return spring is provided inside the sliding jack. The end of the armature column extending into the sliding jack is provided with a conical extrusion head. A radial extrusion through-hole is provided on the active shaft. The inner end of the hammer near the active shaft is provided with an extrusion section adapted to be inside the extrusion through-hole. The end of the extrusion section is provided with an extrusion inclined surface. When the electromagnet drives the armature column to move to the braking position, the conical surface of the extrusion head of the armature column abuts against the extrusion inclined surface, so that the hammer moves radially outwards to the termination position.

[0028] The electromagnet of the present invention works when powered off. When the electromagnet is powered on, the electromagnetic attraction overcomes the elastic force of the return spring, and the clamp body is located at the initial position in the middle. When the elevator control system detects that the elevator has a fault and thus ascends or descends rapidly, or detects that the speed limiter has a mechanical fault and cannot act to brake the car, the control system powers off the electromagnet, and the return spring drives the armature column to move axially. At this time, the extrusion head at the end of the armature column can push open the hammers arranged oppositely in the radial direction, so that the overlapping ends at the outer ends of the hammers overlap with the limit blocks on the driven shaft, and then the driven shaft is engaged with the active shaft to achieve buffering, deceleration and braking of the car, thereby further improving the safety of the elevator. That is to say, when the elevator has a power failure fault, the return spring of the electromagnet can also drive the armature column to move, and then achieve the buffer braking of the car to prevent the car from ascending or descending by itself.

[0029] Therefore, the present invention has the following beneficial effects: it can effectively perform two-way braking on the car deviating from the normal moving speed, thereby ensuring high safety of the car, simplifying the structure of the braking system, simulating the real braking scenario to perform simulation detection on the braking system, thereby ensuring its safety and reliability, and at the same time making an evaluation on the state and service life of the braking system by recording, comparing and analyzing the detection data. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic structural diagram of the present invention.

[0031] Figure 2 is a schematic structural diagram of a safety clamp.

[0032] Figure 3 is a schematic structural diagram of the back of the safety clamp.

[0033] Figure 4 is a schematic installation structural diagram of the decomposition of the clamp body return spring.

[0034] Figure 5 is a schematic structural diagram of a speed limiter.

[0035] Figure 6 is a partial cross-sectional view of the first speed limiter.

[0036] Figure 7 It is a partial sectional view of the second type of speed limiter.

[0037] In the figure: 1. Frame; 11. Limit sleeve; 2. Driving shaft; 21. Pulley; 211. Sliding groove; 22. Hammer; 221. Lapping end; 222. First inclined surface; 223. Extrusion section; 23. Spring seat; 24. Hinged connecting rod; 25. Sliding jack; 3. Driven shaft; 31. Limit block; 311. Second inclined surface; 32. Speed regulating spring; 33. Lapping sleeve; 34. Driving swing arm; 4. Machine base; 41. Clamping sleeve; 411. Shoulder; 42. Locking nut; 43. Adjusting nut; 44. Positioning card plate; 45. Outer wedge block return spring; 46. Special-shaped tension spring; 5. Clamp body; 51. Stop block; 511. Sliding groove; 52. Limit stop block; 53. Driving slider; 54. Guide bar; 541. Sliding bar; 55. Clamp body return spring; 56. Driving shaft; 6. Inner wedge block; 61. Braking surface; 62. Inner driving inclined surface; 7. Outer wedge block; 71. Outer driving inclined surface; 8. Braking coil spring; 9. Electromagnet; 91. Armature iron column; 911. Extrusion head. Specific embodiments

[0038] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0039] Embodiment 1: As Figure 1 shown, a safety braking system for a traction elevator car guide rail is applicable to emergency braking when the car of a traction elevator makes a rapid lift or descent to ensure the safe use of the elevator. Specifically, it includes a speed limiter and a safety clamp. The speed limiter includes a frame 1, a driving shaft 2 arranged on the frame, and a driven shaft 3 coaxially arranged with the driving shaft. A pulley 21 is key-connected to the driving shaft for winding a steel wire rope for towing the car around the pulley. When the car makes a normal lift or descent, the steel wire rope rotates the pulley, and then drives the driving shaft to rotate, and the rotation of the driving shaft has a linear relationship with the lift or descent speed of the car.

[0040] In addition, a centrifugal clutch structure can be arranged between the driven shaft and the driving shaft. When the driving shaft rotates at a normal speed, the centrifugal clutch structure does not act, and the driving shaft and the driven shaft are separated. At this time, the resistance of the driving shaft is close to zero, and the friction between the steel wire rope and the pulley is static friction. Correspondingly, the tension formed by the steel wire rope is extremely small. When the car makes a rapid lift or descent, so that the rotation speed of the driving shaft reaches or exceeds a rated value, the centrifugal clutch structure can make the driving shaft and the driven shaft engage under the action of centrifugal force, and the driving shaft can drive the driven shaft to rotate.

[0041] In addition, as Figure 1 , Figure 2 , Figure 3As shown, the safety gear includes a base 4, a jaw body 5 movably arranged on the front of the base, and an elastic positioning device. The speed governor and the safety gear are associated through an associated mechanism driven by the tension of the wire rope of the traction car. When the car moves up and down rapidly, the tension of the wire rope can drive the jaw body to move up and down through the associated mechanism. In addition, at least two upper and lower stoppers 51 are arranged on the front of the jaw body. Two left and right inner wedges 6 are movably arranged side by side within the moving area formed by the upper and lower stoppers on the jaw body. The opposite inner planes of the inner wedges are braking surfaces 61 for braking the car guide rail. The outer sides of the inner wedges facing away from each other are inner driving inclined surfaces 62 that are inclined outward from top to bottom, so that the inner driving inclined surfaces of the two inner wedges are arranged in a positive eight-character shape. That is to say, the inner wedges are wedge-shaped parts with a small upper end and a large lower end. In addition, a movable outer wedge 7 is arranged outside the inner wedge. The inner side surface of the outer wedge close to the inner wedge is an outer driving inclined surface 71 that cooperates with the inner driving inclined surface, so that the outer wedge is a wedge-shaped part with a large upper end and a small lower end. Moreover, a limit mechanism for limiting the positions of the inner wedge and the outer wedge in the up and down direction needs to be arranged on the base. The elastic positioning device, on the one hand, makes the large ends of the inner wedges and the outer wedges move away from each other in the up and down direction, and on the other hand, makes the inner driving inclined surface of the inner wedge and the outer driving inclined surface of the outer wedge approach each other. At this time, the limit mechanism makes the large end of the inner wedge located at the lowest initial position, and the large end of the outer wedge is located at the highest initial position. Correspondingly, the distance between the braking surfaces of the two inner wedges is the largest, and the car of the elevator can move up and down freely. When the rotational speed of the driving shaft reaches or exceeds the rated speed, the centrifugal clutch structure engages the driving shaft and the driven shaft. At this time, the speed governor drives the jaw body to move up or down through the associated mechanism. If the jaw body moves up, the stopper at the lower part of the jaw body pushes the inner wedge upward, so that while the inner and outer wedges approach each other in the up and down direction, the inner wedge moves laterally inward. At this time, the two inner wedges approach each other and enter the braking state of clamping the car guide rail. If the jaw body moves down, the stopper at the upper part of the jaw body pushes the outer wedge downward, so that while the inner and outer wedges approach each other in the up and down direction, the inner wedge moves laterally inward. At this time, the two inner wedges approach each other and enter the braking state of clamping the car guide rail. It can be understood that limit blocks 52 that abut against the corresponding outer wedges can be arranged on the left and right sides of the jaw body, so as to limit the outward movement of the outer wedges. In addition, needle roller rows can be arranged between the outer wedge and the limit block and between the inner and outer driving inclined surfaces of the inner and outer wedges, so as to reduce the frictional resistance between them and avoid the self-locking phenomenon of jamming between the inner and outer wedges, which is beneficial to the reset of the safety gear after the elevator fault is eliminated.

[0042] To achieve a good buffering effect during the braking of the safety gear, a damping spring for restricting the rotation of the driven shaft can be arranged on the speed governor. Specifically, as Figure 5 、 Figure 6As shown in the figure, we can fixedly connect a limit sleeve 11 to the frame. One end of the driven shaft away from the driving shaft extends into the limit sleeve, and a gap is formed between the driven shaft and the limit sleeve. A braking coil spring 8 is sleeved on the part of the driven shaft extending into the limit sleeve. One end of the braking coil spring is fixedly connected to the frame, and the other end of the braking coil spring is fixedly connected to the driven shaft. This braking coil spring constitutes a damping spring that restricts the rotation of the driven shaft. When the driving shaft drives the driven shaft to rotate forward, the braking coil spring gradually tightens. Correspondingly, the tension of the steel wire rope on the pulley gradually increases, and static friction is formed between the pulley and the steel wire rope. When the braking coil spring is finally tightly wound around the driven shaft, the driven shaft stops rotating. Correspondingly, the driving shaft and the pulley stop rotating, and dynamic friction is formed between the steel wire rope and the pulley. At this time, the tension of the steel wire rope reaches the maximum. We can use the tension of the steel wire rope to drive the action of the jaws of the safety clamp, so that the safety clamp forms a braking friction force that increases from small to large. Similarly, when the driving shaft drives the driven shaft to rotate in the reverse direction, the braking coil spring gradually relaxes. Correspondingly, the tension of the steel wire rope on the pulley gradually increases, and static friction is formed between the pulley and the steel wire rope. When the braking coil spring finally clings to the inner side wall of the limit sleeve, the driven shaft stops rotating. Correspondingly, the driving shaft and the pulley stop rotating, and dynamic friction is formed between the steel wire rope and the pulley. At this time, the tension of the steel wire rope reaches the maximum, so that the safety clamp forms an increasing reverse braking friction force. That is to say, during the braking process of the car, the braking coil spring makes the tension output by the steel wire rope gradually increase from zero, so that the safety clamp forms an increasing frictional braking force on the car guide rail. Compared with other forms of springs, the braking coil spring has a large rotational contraction amount. On the one hand, it can significantly reduce the external dimensions of the reducer, and at the same time, it can effectively improve the buffering effect during braking, avoid damaging the car guide rail, and then can realize the detection of the simulation of the real scene of the braking system, ensuring the safety, effectiveness and reliability of the braking system.

[0043] It should be noted that since the power of the safety clamp in this solution comes from the tension of the steel wire rope during the lifting of the car, during the braking process of the car, the steel wire rope will always provide power to the safety clamp to keep the jaws in the braking position. That is to say, during the entire braking process, the inner wedge block or the outer wedge block will always be subjected to a pulling force. Therefore, we can make the inner and outer wedge blocks have a large inclination angle, so as to avoid the self-locking phenomenon of the inner and outer wedge blocks during braking. During subsequent maintenance, we only need to move the car in the reverse direction to easily unlock and reset the braking device.

[0044] Further, the centrifugal clutch structure of the present invention includes a speed regulating spring 32, a hammer 22 radially disposed on the end face of the pulley and a spring seat 23, and a limiting block 31 connected to the driven shaft. The hammer and the spring seat are adapted to be arranged in a sliding groove 211 radially disposed on the end face of the pulley. The sliding groove can be a T-shaped groove or a dovetail groove, so that the hammer and the spring seat can move radially on the end face of the pulley. In addition, a hinged connecting rod 24 is arranged between the hammer and the spring seat. One end of the hinged connecting rod is hinged to the hammer, and the other end is hinged to the spring seat. The speed regulating spring is located in the sliding groove provided with the spring seat on the pulley. The inner end of the speed regulating spring presses against the driving shaft, and the outer end presses against the spring seat, so that the spring seat is located at an initial position away from the driving shaft. The spring seat makes the hammer in an initial position close to the driving shaft through the hinged connecting rod. At this time, the driving shaft and the driven shaft are in a separated state, and the driving shaft can rotate idly relative to the driven shaft. When the driving shaft rotates, the centrifugal force makes the hammer move radially outwards along the sliding groove. The hammer makes the spring seat move radially inwards through the hinged connecting rod. At this time, the speed regulating spring is compressed. When the rotational speed of the driving shaft reaches or exceeds the rated speed, the centrifugal force makes the hammer move radially outwards along the sliding groove to a termination position away from the driving shaft. The hammer then makes the spring seat move radially inwards to a termination position close to the driving shaft through the hinged connecting rod. The outer end of the hammer abuts against the limiting block. At this time, the driving shaft and the driven shaft are in an engaged state, and the driven shaft rotates together with the driving shaft.

[0045] As a preferred solution, we can set a cross-shaped sliding groove on the end face of the pulley. Correspondingly, 2 of the above-mentioned hammers are arranged in one of the sliding grooves, and the 2 hammers are symmetrically arranged on both sides of the driving shaft. Similarly, 2 of the above-mentioned spring seats are arranged in the other sliding groove, and the 2 spring seats are symmetrically arranged on both sides of the driving shaft, so that the hammers and the spring seats are distributed in a cross shape around the driving shaft. Of course, we need to respectively arrange the above-mentioned hinged connecting rods between each hammer and the 2 spring seats. The 4 hinged connecting rods are hinged into a rhombus, and the speed regulating springs are respectively arranged between the spring seats and the driving shaft. In order to reliably position the speed regulating spring, we can respectively set positioning grooves on the inner side of the spring seat close to the driving shaft and on the outer side of the driving shaft close to the spring seat. The outer end of the speed regulating spring is located in the positioning groove of the spring seat and presses against the spring seat, and the inner end of the speed regulating spring is located in the positioning groove of the driving shaft and presses against the driving shaft.

[0046] Furthermore, on both sides of the outer end of the hammer away from the driving shaft, first inclined surfaces 222 that incline outward from the inside to the outside are provided, so that the outer end of the hammer forms a lap end 221 in the shape of a dovetail with a larger outer part and a smaller inner part. A lap sleeve 33 is fixedly provided at one end of the driven shaft close to the driving shaft, and four such limiting blocks are provided on the inner side wall of the lap sleeve, and the four limiting blocks are evenly distributed in the circumferential direction. Both sides of the limiting block are second inclined surfaces 311 adapted to the first inclined surfaces, so that the limiting block is in the shape of a dovetail. When the hammer extends out of the sliding groove under the action of centrifugal force, the first inclined surface of the dovetail-shaped lap section can abut against the second inclined surface of the limiting block, so that the driven shaft is engaged with the driving shaft. At this time, the lap section and the limiting block form a barb structure, which can avoid the retraction of the hammer due to the decrease in speed, and thus can achieve the complete braking of the car.

[0047] The associated mechanism of the present invention includes a driving swing arm 34 and a driving slider 53 provided on the clamp body. One end of the driving swing arm is hinged to the driving slider, and the other end of the driving swing arm is provided with a driving shaft 56 rotatably connected to the machine base, and the driving shaft is associated with the steel wire rope. When the car moves up and down at an excessive speed, the tension of the steel wire rope on the pulley gradually increases, so as to drive the driving swing arm to swing up and down through the driving shaft, and then drive the clamp body to move in the up and down direction through the driving slider. Since the driving swing arm will cause a lateral displacement of the driving slider when swinging up and down, a lateral sliding groove can be provided on the back of the clamp body, and the driving slider is adapted to be in the sliding groove. When the driving swing arm swings up and down, the clamp body can be driven to move up and down through the driving slider hinged thereto. At the same time, the driving slider can form a left-right lateral movement in the sliding groove on the back of the clamp body.

[0048] In order to enable the clamp body to be reliably positioned at the initial position in the middle, two vertical rectangular insertion holes can be coaxially provided on the base, a guiding strip 54 is adapted in the rectangular insertion hole, a lateral sliding strip 541 is provided at the inner ends of the two guiding strips close to each other, the guiding strip and the sliding strip are connected into a T shape, and the two sliding strips respectively abut against the upper and lower sides of the hinge shaft of the driving swing arm and the driving slider. A clamp body return spring 55 is sleeved on the guiding strip, and the inner end of the clamp body return spring presses against the sliding strip. The two clamp body return springs position the hinge shaft of the driving swing arm and the driving slider at the middle position through the sliding strip, and then elastically position the clamp body at the initial position in the middle through the driving slider. When the driven shaft drives the driving slider to move through the swing of the driving swing arm and then drives the clamp body to move up and down, the hinge shaft of the driving swing arm and the driving slider can move laterally between the two sliding strips to avoid jamming.

[0049] For the convenience of installation, square clamping holes can be respectively provided on the upper and lower sides of the base, a clamping sleeve 41 is provided in the clamping hole, and the inner hole of the clamping sleeve is the rectangular insertion hole slidably connected to the guiding strip on the corresponding side. As Figure 5As shown in the figure, a protruding shoulder 411 is provided in the middle of the outer side of the snap sleeve for axial positioning during the assembly of the snap sleeve. The outer side wall of the part of the snap sleeve located outside the shoulder is a regular quadrangular prism surface adapted to fit in the corresponding snap hole. Transition cylindrical surfaces are provided at the four corners of the regular quadrangular prism surface, and external threads are provided on the transition cylindrical surfaces. A locking nut 42 is threadedly connected to the outer end of the snap sleeve protruding from the snap hole, thereby fixing the snap sleeve to the base. During processing, we can first make the part of the snap sleeve located outside the shoulder into an external threaded column, and then cut four flat parts on the external threaded column. The four flat parts are evenly distributed in the circumferential direction. In addition, the part of the snap sleeve located inside the shoulder is an external threaded column, and two adjusting nuts 43 are threadedly connected. When we rotate the adjusting nut that abuts against the reset spring of the pliers body, the pre-tightening elastic force of the pliers body reset spring can be adjusted, so as to ensure that the pliers body is accurately positioned at the initial position in the middle. Then tighten the other adjusting nut so that the two adjusting nuts are closely abutted against each other to form self-locking and prevent the adjusting nut from loosening by itself.

[0050] In order to determine the initial positions of the inner and outer wedges, the limiting mechanism of the present invention includes two vertically arranged positioning cards 44 provided on the left side of the front of the base, and two vertically arranged positioning cards provided on the right side of the front of the base. A sliding space for accommodating the inner and outer wedges is formed between the lower side of the upper positioning card and the upper side of the lower positioning card. Of course, the lower sides of the upper positioning cards on the left and right sides are at the same height, and the upper sides of the lower positioning cards on the left and right sides are at the same height, so that the initial positions of the inner and outer wedges on the left side are the same as the initial positions of the inner and outer wedges on the right side. When the inner and outer wedges are in the initial position in the up and down direction, the lower side of the upper positioning card abuts against the end face of the large end of the outer wedge on the corresponding side, and the upper side of the lower positioning card abuts against the end face of the large end of the inner wedge on the corresponding side.

[0051] In addition, two of the above-mentioned stoppers are provided on the upper part of the pliers body, and two of the above-mentioned stoppers are provided on the lower part of the pliers body. A sliding groove 511 adapted to the width of the positioning card is provided in the middle of the stopper. The upper positioning card on the left side slides in the upper sliding groove on the left side, and the lower positioning card on the left side slides in the lower sliding groove on the left side. Correspondingly, the upper positioning card on the right side slides in the upper sliding groove on the right side, and the lower positioning card on the right side slides in the lower sliding groove on the right side. When the pliers body moves upward, the stopper on the lower part of the pliers body drives the inner wedge that abuts against the lower positioning card of the base upward. The inner and outer wedges approach each other in the up and down direction, and the two inner wedges approach each other and enter the braking state. When the pliers body moves downward, the stopper on the upper part of the pliers body drives the outer wedge that abuts against the upper positioning card of the base downward. The inner and outer wedges approach each other in the up and down direction, and the two inner wedges approach each other and enter the braking state. It should be noted that the lower side of the upper stopper should be flush with the lower side of the upper positioning card.

[0052] Since the positioning latch on the base is slidably located in the corresponding sliding groove on the pliers body, the pliers body and the base form a reliable sliding connection, enabling the pliers body to move up and down relative to the base. At the same time, the stop block is divided into left and right parts by the sliding groove and the positioning latch fitted in the sliding groove. Therefore, when the pliers body moves up and down, it can ensure sufficient contact area with the inner wedge block or the outer wedge block, and further enable the inner and outer wedge blocks to approach each other in the up and down direction to clamp the car guide rail. It can be understood that the lower side edge of the upper stop block should be flush with the lower side edge of the upper positioning latch, and correspondingly, the upper side edge of the lower stop block should be flush with the upper side edge of the lower positioning latch. That is to say, when the moving area defined by the limiting mechanism composed of the upper and lower positioning latches and the moving area composed of the upper and lower stop blocks are the same in the up and down direction, the large end of the inner wedge block abuts against the upper side edges of the lower stop block and the positioning latch at the same time, and the large end of the outer wedge block abuts against the lower side edges of the upper stop block and the positioning latch at the same time. In this way, when starting to move the pliers body, the inner and outer wedge blocks can approach each other in the up and down direction, and then the inner wedge block moves inward to clamp the car guide rail, avoiding the empty stroke of the pliers body.

[0053] In order to reliably position the inner and outer wedge blocks in the initial position, the elastic positioning device of the present invention includes two outer wedge block return springs 45 on the left and right, and a plurality of special-shaped tension springs 46 arranged between the inner and outer wedge blocks. The outer wedge block return spring can be a cylindrical compression spring. The lower end of the outer wedge block return spring presses against the base, and the upper end presses against the small end of the lower part of the corresponding outer wedge block on one side, so that the large end of the outer wedge block abuts against the upper positioning latch on the corresponding upper side. In addition, the special-shaped tension spring is formed by a spring wire reciprocating left and right in the same plane to form a snake shape, and insertion sections perpendicular to the plane where the special-shaped tension spring is located are bent at both ends of the special-shaped tension spring. Correspondingly, insertion holes are respectively arranged on the front and back surfaces of the inner wedge block and the front and back surfaces of the outer wedge block. The insertion section at one end of the special-shaped tension spring is inserted into the insertion hole of the inner wedge block, and the insertion section at the other end of the special-shaped tension spring is inserted into the insertion hole of the corresponding outer wedge block, thereby forming a pulling force between the inner and outer wedge blocks, and further enabling the inner wedge block to be located in the initial position of abutting against the lower positioning latch. Of course, at this time, the insertion hole on the inner wedge block should be higher than the corresponding insertion hole on the outer wedge block, so that the pulling force of the special-shaped tension spring on the inner wedge block can generate a downward component force to ensure that the inner wedge block is positioned in the initial position of abutting against the lower positioning latch.

[0054] To ensure the reliability of car braking, we can also set an electromagnet 9 at one end of the frame near the driving shaft and far from the driven shaft. A sliding jack 25 is coaxially set on the end face of the driving shaft far from the driven shaft. An armature iron column 91 driven by the electromagnet is inserted into the sliding jack. The armature iron column is connected to a return spring (not shown in the figure). The end of the armature iron column extending into the sliding jack is provided with a conical extrusion head 911. Correspondingly, a rectangular extrusion through-hole is radially set on the driving shaft, and the inner end of the flyweight near the driving shaft is provided with a reduced extrusion section 223, so as to form a step between the extrusion section and the flyweight. When the flyweight is in the initial position, the extrusion section is fitted in the extrusion through-hole. In addition, the end of the extrusion section is provided with an extrusion inclined surface, and the inclination direction of the extrusion inclined surface is the same as that of the conical surface of the extrusion head of the armature iron column.

[0055] When the elevator is running normally, the electromagnet is energized to generate magnetic suction force, so that the armature iron column overcomes the elastic force of the return spring and is located at the initial position at the outer end of the sliding jack. When the elevator control system detects that the elevator fails and the car gets out of control and moves up and down at a speed lower than the set maximum speed, or detects that the speed governor has a mechanical failure and cannot operate, the control system energizes the electromagnet. The electromagnet drives the armature iron column to move inward in the sliding jack to the braking position. The conical surface of the extrusion head of the armature iron column abuts against the extrusion inclined surface of the flyweight, so as to push the flyweight to move radially outward to the termination position. The overlapping end at the outer end of the flyweight overlaps with the limit block on the driven shaft. The driven shaft is engaged with the driving shaft, and the buffering deceleration and braking of the car can be realized, so as to further improve the safety of the elevator.

[0056] It should be noted that in this embodiment, the side of the base where the clamp body and the inner and outer wedge blocks are set is called the front, and the other side is called the back. For the inner wedge block, the side close to the corresponding outer wedge block is the outer side, and the side where the two inner wedge blocks are close to each other is the inner side.

[0057] Embodiment 2: To achieve a good buffering effect during the braking of the safety clamp, as Figure 7 shown, we can make the driven shaft form a rotational connection with the overlapping sleeve. A limit sleeve 11 is fixedly connected to the frame. One end of the driven shaft far from the driving shaft extends into the limit sleeve, and a gap is formed between the driven shaft and the limit sleeve. A braking coil spring 8 is sleeved on the part of the driven shaft extending into the limit sleeve. One end of the braking coil spring is fixedly connected to the overlapping sleeve, and the other end of the braking coil spring is fixedly connected to the driven shaft. The braking coil spring constitutes a damping spring, so that an elastic connection can be formed between the driving shaft and the driven shaft. In addition, one end of the driven shaft extending into the limit sleeve is coaxially connected to the driving shaft on the safety clamp. The rest of the structure is the same as that in Embodiment 1 and will not be described here.

[0058] When the car ascends or descends at an excessive speed, the pulley engages with the lapping sleeve, thereby driving the lapping sleeve to rotate. At this time, the lapping sleeve drives the driven shaft to rotate through the braking coil spring, and the driven shaft drives the caliper body to act through the driving shaft. The two inner wedges then clamp the car guide rail, and thus start braking the car guide rail. When the pulley continues to rotate, since the driven shaft cannot rotate at this time, relative rotation is formed between the pulley and the driven shaft. The braking coil spring is gradually tightened or gradually relaxed. Correspondingly, the torque transmitted from the pulley to the driven shaft through the braking coil spring gradually increases, and correspondingly, the force transmitted from the driven shaft to the caliper body through the driving shaft gradually increases, thereby gradually increasing the braking friction force formed by the inner wedges. At this time, static friction is formed between the pulley and the steel wire rope. When the braking coil spring is finally tightly wound around the driven shaft or closely adheres to the inner side wall of the limit sleeve, the pulley cannot continue to rotate relative to the driven shaft, and dynamic friction is formed between the steel wire rope and the pulley. At this time, the pulley outputs the maximum torque to the driving shaft through the driven shaft, and the braking friction force of the safety clamp on the car guide rail reaches the maximum.

Claims

1. A safety braking system for a traction elevator car guide rail, comprising an interrelated speed governor and safety tongs, characterized in that, The speed limiter includes a frame, a driving shaft, a driven shaft coaxially arranged on the frame, and a damping spring for restricting the rotation of the driven shaft. The wire rope for hoisting the car bypasses the pulley arranged on the driving shaft, and a centrifugal clutch structure is provided between the driven shaft and the driving shaft. The safety gear includes a base, a jaw body movably arranged on the base, and an elastic positioning device. At least two upper and lower stoppers are arranged on the jaw body. Two left and right inner wedges are movably arranged in the jaw body. The opposite planes of the inner wedges are braking surfaces for braking. The outer sides of the inner wedges facing away from each other are inwardly inclined inner driving inclined surfaces. The inner driving inclined surfaces of the two inner wedges are arranged in a V-shaped pattern. A movable outer wedge is arranged outside the inner wedge. The inner side of the outer wedge is an outer driving inclined surface cooperating with the inner driving inclined surface. The base is provided with a limiting mechanism for limiting the positions of the inner wedge and the outer wedge. The elastic positioning device makes the inner driving inclined surface of the inner wedge and the outer driving inclined surface of the outer wedge approach each other, and the large ends of the inner wedge and the outer wedge are separated from each other in the vertical direction. The limiting mechanism limits the inner and outer wedges in the vertical direction to the initial position, and at this time, the distance between the braking surfaces of the two inner wedges is the largest. When the rotational speed of the driving shaft reaches the rated speed, the centrifugal clutch structure engages the driving shaft and the driven shaft, and the speed limiter drives the jaw body to move in the vertical direction through an associated mechanism. The stoppers on the jaw body make the large ends of the inner and outer wedges approach each other in the vertical direction, so that the two inner wedges approach each other and enter the braking state. The centrifugal clutch structure includes a speed regulating spring, a flyweight radially arranged on the end face of the pulley, and a spring seat. A hinged connecting rod is arranged between the flyweight and the spring seat. One end of the hinged connecting rod is hinged to the flyweight, and the other end is hinged to the spring seat. The inner end of the speed regulating spring presses against the driving shaft, and the outer end presses against the spring seat.

2. The safety braking system for the traction elevator car guide rail according to claim 1, characterized in that, The centrifugal clutch structure further includes a limiting block connected to the driven shaft. The speed regulating spring makes the spring seat located at the initial position away from the driving shaft. The spring seat makes the flyweight located at the initial position close to the driving shaft through the hinged connecting rod. At this time, the driving shaft and the driven shaft are in a separated state. When the rotational speed of the driving shaft reaches the rated speed, the centrifugal force makes the flyweight radially move outwards to the end position away from the driving shaft. The flyweight makes the spring seat radially move inwards to the end position close to the driving shaft through the hinged connecting rod. The outer end of the flyweight abuts against the limiting block, and the driven shaft and the driving shaft are in an engaged state.

3. The safety braking system for the traction elevator car guide rail according to claim 2, characterized in that, Both sides of the outer end of the flyweight away from the driving shaft are first inclined surfaces, so that the outer end of the flyweight forms a lap end with a large outer part and a small inner part in the shape of a dovetail. A lap sleeve is arranged at one end of the driven shaft close to the driving shaft. The limiting block is arranged on the inner side wall of the lap sleeve. Both sides of the limiting block are second inclined surfaces adapted to the first inclined surfaces, so that the limiting block is in the shape of a dovetail.

4. A safety braking system for a traction elevator car guide rail according to claim 2, characterized in that, in A limiting sleeve is fixedly connected to the frame. The driven shaft extends into the limiting sleeve. The damping spring is a braking coil spring sleeved on the part of the driven shaft extending into the limiting sleeve. One end of the braking coil spring is fixedly connected to the frame, and the other end is fixedly connected to the driven shaft.

5. A safety braking system for a traction elevator car guide rail according to claim 1, characterized in that, The associated mechanism includes a driving swing arm and a driving slider arranged on the pliers body. One end of the driving swing arm is hinged to the driving slider. The pulling force of the steel wire rope drives the driving swing arm to swing, and then drives the pliers body to move in the up-and-down direction through the driving slider.

6. The safety braking system for the traction elevator car guide rail according to claim 1, characterized in that, Two vertical rectangular insertion holes are coaxially arranged on the base. Guide bars are fitted in the rectangular insertion holes. One ends of the two guide bars close to each other are provided with horizontal sliding bars. The two sliding bars respectively abut against the upper and lower sides of the hinge shaft of the driving swing arm and the driving slider. A pliers body return spring is sleeved on the guide bar.

7. A safety braking system for a traction elevator car guide rail according to claim 6, characterized in that, Square clamping holes are respectively arranged on the upper and lower sides of the base. A clamping sleeve with the rectangular insertion hole is arranged in the clamping hole. The guide bar is fitted in the rectangular insertion hole of the corresponding clamping sleeve on one side. A shoulder protruding outwards is arranged in the middle of the outer side surface of the clamping sleeve. The outer side wall of the part of the clamping sleeve located outside the shoulder is a regular quadrangular prism surface adapted to be fitted in the corresponding clamping hole. Two adjusting nuts are threadedly connected to the outer side wall of the part of the clamping sleeve located inside the shoulder. One end of the pliers body return spring abuts against the sliding bar on the corresponding side, and the other end is sleeved on the clamping sleeve on the corresponding side and abuts against the adjusting nut. Transition cylindrical surfaces are arranged at the four corners of the regular quadrangular prism surface. External threads are arranged on the transition cylindrical surfaces. A locking nut is threadedly connected to the outer end of the clamping sleeve protruding out of the clamping hole.

8. A safety braking system for a traction elevator car guide rail according to claim 1, characterized in that, The limiting mechanism includes two upper and lower positioning clamping plates arranged on the left side of the front surface of the base and two upper and lower positioning clamping plates arranged on the right side of the front surface of the base. A sliding space for accommodating the inner and outer wedges is formed between the two upper and lower positioning clamping plates. When the inner and outer wedges are in the initial position in the up-and-down direction, the upper positioning clamping plate abuts against the end surface of the large end of the outer wedge on the corresponding side, and the lower positioning clamping plate abuts against the end surface of the large end of the inner wedge on the corresponding side.

9. A safety braking system for a traction elevator car guide rail according to claim 8, characterized in that, Two of the above-mentioned stoppers are arranged on the upper part of the pliers body, and two of the above-mentioned stoppers are arranged on the lower part of the pliers body. A sliding groove is arranged in the middle of the stopper. The positioning clamping plate is slidably located in the corresponding sliding groove. When the pliers body moves upwards, the stopper on the lower part of the pliers body drives upwards to abut against the inner wedge of the positioning clamping plate at the lower part of the base. The inner and outer wedges approach each other in the up-and-down direction, and the two inner wedges approach each other and enter the braking state. When the pliers body moves downwards, the stopper on the upper part of the pliers body drives downwards to abut against the outer wedge of the positioning clamping plate at the upper part of the base. The inner and outer wedges approach each other in the up-and-down direction, and the two inner wedges approach each other and enter the braking state.

10. A safety braking system for a traction elevator car guide rail according to claim 9, characterized in that, An electromagnet is arranged on the frame at a position close to one end of the driving shaft away from the driven shaft. A sliding insertion hole is arranged in the driving shaft. An armature column driven by the electromagnet is arranged in the sliding insertion hole. The end of the armature column extending into the sliding insertion hole is provided with a conical extrusion head. A radial extrusion through hole is arranged on the driving shaft. The inner end of the fly hammer close to the driving shaft is provided with an extrusion section adapted to be fitted in the extrusion through hole. An extrusion inclined surface is arranged at the end of the extrusion section. When the electromagnet drives the armature column to move to the braking position, the conical surface of the extrusion head of the armature column abuts against the extrusion inclined surface, so that the fly hammer moves radially outwards to the termination position.

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