47results about How to "Prevent being stuck" patented technology

The invention discloses a washing machine inner barrel with a barrel wall self-cleaning function and a washing machine, wherein the inner barrel is coaxially arranged in an outer barrel of the washing machine, cleaning particles for cleaning the barrel wall are arranged between the inner barrel and the outer barrel, and the bottom of the inner barrel of the washing machine is externally provided with particle moving spaces for charging the cleaning particles and leading the cleaning particles to move along with water flow to obtain a moving acceleration so as to clean the wall between the bottom of the inner barrel and the bottom of the outer barrel by means of collision and friction. The particle moving spaces are a plurality of groove spaces formed by strengthening ribs outside the bottom of the inner barrel, the gaps between the strengthening ribs and the bottom of the outer barrel can lead the cleaning particles to be charged along with the water flow, and the sizes of groove spaces can lead at least five of cleaning particles to be put. The washing machine inner barrel and the washing machine disclosed by the invention are simple in structure, and the design and the distribution of the strengthening ribs are changed when the bottom of the inner barrel is injection-molded, so that the spaces for the cleaning particles to move along with the water flow between the bottom of the inner barrel and the bottom of the outer barrel exist, the material cost can not be additively increased, and the strength of the inner barrel can not be reduced.

The invention relates to a double-shield TBM getting stuck prevention method. After geological conditions are accurately grasped, a double-shield TBM is subjected to risk prevention and control or improvement, risk prevention and control of the double-shield TBM are to ensure that the TBM efficiently and continuously tunnels, or guarantee a good TBM gesture, or reasonable tunneling parameters areselected, or the expanding and mining amount is increased, or a single-shield tunneling mode is reasonably adopted, or the combination of one or more kinds of advanced fastening stratum processing isconducted; the TBM is subjected to the combination of one or more kinds of cutter improvement, or shield body improvement, or torque increasing or thrust increasing. The problem that the double-shieldTBM easily gets stuck in the construction process is solved.

The invention discloses a novel compound anti-clamping dual-shield TBM and a construction method thereof. The problem that an existing dual-shield TBM is large in crash risk and single in constructionmode is solved. The TBM comprises a cutter disc, a front shield, a supporting shield and a tail shield, the cutter disc is arranged at the front end of the front shield and connected with a main driver arranged on a shield body, the rear end of the front shield is connected with the supporting shield, an outer stretchable shield and an inner stretchable shield are arranged on the supporting shield, the inner stretchable shield is fixedly connected with the main driver, the outer stretchable shield is movably connected with the main driver, a supporting boot and a double crossed shaped beam are arranged inside the supporting shield, the tail shield is fixedly connected with the double crossed shaped beam, a segment erector and an advance drilling machine are connected to the double crossedshaped beam, the advance drilling machine is located above the segment erector, and an advance grouting tube is arranged at the upper portion of the supporting shield. The crash of the dual-shield TBM in a weak stratum can be avoided in various ways such as rapid lifting and expanding excavation of the cutter disc, dynamic supporting of the shield bodies, advance detection and advance grouting. The TBM is good in trafficability characteristic and high in working efficiency.

The invention provides a sand-proof oil-release oil well pump, which mainly solves the problems that the oil release device in the existing oil pipe string has complex structure and operation and an oil pump piston is easy to be blocked by sands. The invention is characterized in that a variable diameter pump cylinder (5) with a small upper part and a large lower part is connected between an upper joint (1) and a lower joint (2); a piston (3) passes through the small-diameter section on the upper part of the variable diameter pump cylinder (5) and the lower part of the piston (3) is arranged in the large-diameter section at the lower part of the variable diameter pump cylinder (5); the lower end of the piston (3) is always below the small-diameter section of the variable diameter pump cylinder (5) within the stroke; the piston (3) and the small-diameter section at the upper part of the variable diameter pump cylinder (5) adopt a sealable interference fit between; an oil release hole (6) is arranged on the side wall of the small diameter section at the upper part of the variable diameter pump cylinder (5). The oil release hole of the sand-proof oil-release oil well pump is arranged on the side wall of the pump cylinder, and the invention is characterized in that the structure is simple, the operation is convenient, the piston is easy to be blocked by sands, and the operation period is long.

The invention provides an intelligent multi-functional sewing machine and particularly relates to the technical field of sewing machine manufacturing. The intelligent multi-functional sewing machine is characterized in that a composite transmission wheel is fixed on a rear output shaft and equipped with a swinging column; the swinging column is positioned, runs and transfers a swinging source inside the front positioning part of a rotating connecting fork rod, as well as is driven by a driving source to be positioned, idle and perform thread trimming, thread loosening and presser foot liftingactions on the propping circular arc-shaped surface of the rotating connecting fork rod; a presser foot lifting cam component is rotationally propped against a presser foot lifting ejector plate; thepresser foot lifting ejector plate acts on a presser foot lifting ejector rod so as to lift a presser foot; a thread loosening salient point has the function of triggering a thread loosening device ejector rod; a thread trimming crank, namely a pushing component, is mounted and fixed on a front output shaft; and a rotating ball arranged on the thread trimming crank runs and performs thread trimming action in a thread trimming cam. According to the intelligent multi-functional sewing machine, the four actions of presser foot lifting, thread loosening, reinforcing and back-and-forth sewing, as well as thread trimming are controlled through a motor, so that the sewing machine production cost can be greatly reduced, and the problem that the sewing machine manufacturing cost and the noise are high because electromagnets are adopted for thread loosening can be effectively solved.

The invention discloses a large freight vehicle tail anti-impact device which comprises a front face impact board. An oblique board is arranged at the upper end of the front face impact board. A height adjusting mechanism fixed to the tail end of a vehicle girder is arranged on the inner side of the oblique board. A connecting frame is arranged on the inner wall face of the front face impact board. A limiting buffering mechanism located on the two sides of the tail of the vehicle girder is hinged to the two ends of the connecting frame and located on the inner side of the height adjusting mechanism. The limiting buffering mechanism comprises two bases fixed to the vehicle girder. A horizontal guide rod is arranged between the two bases and sleeved with a horizontal sliding seat. The horizontal sliding seat is hinged to the connecting frame. A buffer spring is further arranged on the side face of the horizontal sliding seat, wherein the horizontal guide rod is sleeved with the buffer spring. The large freight vehicle tail anti-impact device has the beneficial effects that the safety protection performance can be improved.

The invention relates to a drilling resistivity advanced detection device used for a TBM and a detection method thereof. The detection device comprises an external bushing, an internal transmission rod, electrodes, a rotating bearing and a position limiting device. The internal circle of the rotating bearing sleeves the internal transmission rod. The electrodes are arranged in the electrode accommodating parts in the external bushing, and the head parts face the external side of the side wall of the external bushing. The rear parts of the electrodes are connected with one end of electrode compression leads. The other end of the electrode compression leads is connected with the external circle of the rotating bearing. The rear ends of the electrodes are provided with springs. The position limiting device comprises an external bushing blocking part and an internal transmission rod protruding part which are matched with each other. When the protruding part and the blocking part have an overlapped part, the external bushing stops axial relative movement of the internal transmission rod. When the positions of protruding part and the blocking part are staggered, the internal transmission rod and the external bushing are in the axial free movement state.

The invention discloses an arrangement method of hobs for directly cutting reinforcements in concrete in a shield tunneling machine. A cutter head of the shield tunneling machine is fixedly provided with multiple double-edge hobs and multiple single-edge hobs capable of freely rotating; edges of one part of the multiple double-edge hobs are positioned in a first plane; edges of the other part of the multiple double-edge hobs are positioned in a second plane and / or a third plane; the distance from the second plane to the surface of the cutter head is larger than the distance from the first plane to the surface of the cutter head; the distance from the third plane to the surface of the cutter head is larger than the distance from the second plane to the surface of the cutter head; edges of one part of the multiple single-edge hobs are positioned in the first plane; edges of the other part of the multiple single-edge hobs are positioned in the second plane and / or the third plane; all the edges of the double-edge hobs and the single-edge hobs are numbered in sequence; and when all the edges are arranged as a straight line, tips of the edges are arranged in a saw tooth form.

The invention disclsoes a guide roller device, which comprises a transfer part, multiple first rollers, multiple second rollers, a belt, a second roller moving part, a first roller rotating part, a torque sensor, and a control part. The transfer part transfers objects along a transfer direction. The first rollers are separately arranged in the side parts of the objects along the transfer direction to transfer the objects in the transfer direction. The second rollers are arranged between the first rollers neighboring along the side parts of the objects. The belt is wound on the first and second rollers. The second roller moving part reciprocates the second rollers in a direction to be closed to or to be escaped from the objects.

The invention provides an intelligent multifunctional sewing machine, and particularly relates to the technical field of sewing machine manufacturing. The intelligent multifunctional sewing machine comprises a driving source, a thread cutting crank and a thread cutting cam. The intelligent multifunctional sewing machine is characterized in that the driving source drives a rotary ball of the threadcutting cam to apply rotation force on the thread cutting action face to cut a thread, and the driving source drives the rotary ball of the thread cutting cam to operate to push the thread cutting return face. The intelligent multifunctional sewing machine provided by the invention has the advantages that after a thread cutting mechanism finishes thread cutting in a single direction, the intelligent multifunctional sewing machine is provided with the assisted-reset arrangement for preventing the mechanism from being clamped, the situation that needle breakage of a clamping knife at the clamping position is avoided, and the performance of the sewing machine is more stable and reliable.

The invention relates to an anti-blocking throw-in type draining pump of a coal-bed gas well. The anti-blocking throw-in type draining pump comprises a water extracting and draining part, a piston and a cylinder barrel, wherein the piston is sleeved with the cylinder barrel. The water extracting and draining part is driven by the piston to extract and drain water inside the coal-bed gas well. The water extracting and draining part is fixedly arranged at the bottom of the cylinder barrel. The full-stroke outer circle of the piston is in seal fit with part of the inner circle of the cylinder barrel. The anti-blocking throw-in type draining pump of the coal-bed gas well can effectively prevent the piston from being blocked and can reduce abrasion.

The invention relates to the technical field of vending machines, and discloses a material jam preventing device of a beverage vending machine. The material jam preventing device comprises a main body, wherein a selling cavity and a falling cavity are formed in the inner side of the main body, the selling cavity is positioned above the falling cavity, a semicircular pickup groove is formed in thebottom part of the falling cavity, and a sliding plate and a mounting plate are welded to the inner side of the selling cavity. According to the material jam preventing device of the beverage vendingmachine, a turntable is installed below a material storage pipe, when in use, a corresponding position is selected according to samples displayed on the front surface of the turntable; the turntable is controlled to rotate anticlockwise by means of an output shaft, beverage in the material storage pipe falls into an outer groove of the turntable, the turntable continues to rotate to transfer the beverage onto a sliding plate, the beverage falls onto the buffer plate by means of the inclined sliding plate and finally falls into the pickup groove by means of a guide plate, so that the beverage is flatly placed, the beverage rolls down by means of the inclined sliding plate, and the problems that the beverage is clamped in the falling process, the consumer cannot take commodities and sufferseconomic losses are prevented.

The invention provides a multifunctional structure of an intelligent sewing machine, and particularly relates to the technical field of sewing machine manufacturing. The multifunctional structure is characterized in that a swing column operates in a swing positioning groove of a rotary connecting fork rod, a driving source drives the swing column to perform positioning idling on an abutting arc surface of the rotary connecting fork rod to perform thread trimming, thread loosening and presser foot lifting actions, a composite transmission wheel is further provided with a presser foot lifting cam part, the presser foot lifting cam part abuts against a presser foot lifting top plate in a rotating mode, the presser foot lifting top plate acts on a presser foot lifting top rod to achieve presser foot lifting, the composite transmission wheel is further provided with a thread loosening protruding point, and the thread loosening protruding point is used for triggering a thread loosening device ejector rod. According to the multifunctional structure of the intelligent sewing machine, the problems of high manufacturing cost and high noise of the sewing machine due to adoption of an electromagnet for thread loosening are effectively solved, a purely mechanical thread loosening scheme is ingeniously combined with the presser foot lifting mechanism and a reinforcing seam free sewing pattern stitch length automatic adjusting mechanism, and the excellent technical effect that four sewing actions are achieved under one motor is achieved.

The invention discloses a balance capability training device for rats with brain injury. The device comprises an outer frame bracket, a console and a plurality of training cages, wherein the console is connected to the outer side of the outer frame bracket; the training cages are arranged abreast in the outer frame bracket, and comprise at least one ordinary training cage and at least one forward and backward balance training cage; a treadmill is arranged in each training cage; a forward and backward swinging regulation mechanism is arranged below the forward and backward balance training cage; the console is electrically connected with each treadmill and the forward and backward balance regulation mechanism. The device can be used for simplex treadmill training and implementing a feeling-balance-motion multifunctional habilitation training mode, the experimental requirements of a researcher can be met, and an advanced animal experiment means can be provided for researches on the neural mechanism rehabilitation of brain injury diseases.

The invention relates to the technical field of special-shaped steel pipe machining, in particular to a machining fixing device for a special-shaped steel pipe. The device comprises a supporting mechanism, two clamping mechanisms, a material lifting mechanism and a dust receiving mechanism. When a steel pipe of a semi-circular structure is machined, the inner wall of the steel pipe of the semi-circular structure is fixed through the two clamping mechanisms with the side walls of the arc-shaped structures, meanwhile, steel pipes of different types and of semi-circular structures are expanded and fixed, and the surface of the steel pipe of the semi-circular structure can be comprehensively ground and polished. The surface of the supporting mechanism is slidably connected with the material lifting mechanism located between the two clamping mechanisms, the two clamping mechanisms are loosened when the ground semicircular steel pipe is cut, the material lifting mechanism is adjusted to abutagainst the bottom of the semicircular steel pipe, and saw clamping is avoided; and the dust receiving mechanism used for storing sundries falling when the semicircular steel pipe is cut is installedat the bottom of the supporting mechanism, when the steel pipe is cut, chippings fall into the dust receiving mechanism, and cleaning is convenient.

A power device for jacking pipes comprises four jacks and a support for supporting the jacks and is characterized in that the rear end of each jack is coaxially provided with a small gear, parameters of the four small gears are identical and meshed with a center large gear, and the axes of the four small gears around the center large gear are evenly distributed. The four small gears are located in an outer gear ring and meshed with the outer gear ring. The outer gear ring is fixed on the support. A driving gear is coaxially installed on the center large gear, and the driving gear is connected with a driving motor through a transmission mechanism. The driving motor is fixedly installed on the support. The device can prevent pipes from moving off course in the advancing process, prevent blocking of the pipes, improve pipe abutting connection coaxility and improve the abutting connection quality.

The invention discloses an integrated feeling-balance-motion training device for rats with brain injury. The device comprises an outer frame bracket, a console and a plurality of training cages, wherein the console is connected to the outer side of the outer frame bracket; the training cages are arranged abreast in the outer frame bracket, and comprise at least one forward and backward balance training cage and at least one leftward and rightward balance training cage; a treadmill is arranged in each training cage; a forward and backward swinging regulation mechanism is arranged below the forward and backward balance training cage; a leftward and rightward swinging regulation mechanism is arranged below the leftward and backward balance training cage; the console is electrically connected with each treadmill, the forward and backward balance regulation mechanism and the leftward and rightward swinging regulation mechanism. The device can be used for simplex treadmill training and implementing a feeling-balance-motion multifunctional habilitation training mode, the experimental requirements of a researcher can be met, and an advanced animal experiment means can be provided for researches on the neural mechanism rehabilitation of brain injury diseases.

The invention relates to a testing, adjusting and sealing examining integrated device for a separate injection well. The testing, adjusting and sealing examining integrated device is applied to underground separate layer water injection of an oil field and comprises an underground separate injection tubular column and a testing, adjusting and sealing examining system. The testing, adjusting and sealing examining system comprises an integrated testing, adjusting and sealing examining instrument, and the integrated testing, adjusting and sealing examining instrument comprises a control unit, a flow sensor, an internal pressure sensor, an upper motor, a lead screw, an axial positioning unit, an upper and lower packing unit, an external pressure sensor, a circumferential positioning unit and a rotating unit. The axial positioning unit comprises a positioning block provided with an axial anti-clamping sliding groove, and the lead screw is provided with an upper setting thread and a lower setting thread which are opposite in rotating direction. The flow sensor is an electromagnetic flow sensor. A packing piece is a compression type rubber sleeve or a packing cup. The upper setting thread and the lower setting thread are trapezoidal threads. The two-stage packing element and the setting mechanism of the two-stage packing element are arranged on the integrated testing, adjusting and sealing examining instrument and matched with an efficient water distributor, testing, adjusting, pressure measuring and sealing examining operation can be completed at a time.

The invention discloses a cutting device of a box frame riveting die. A rectangular frame is movably hinged to the right side of the upper surface of a base through a hinge support; an object placingplate is fixedly arranged, right below a cutting wheel, on the upper surface of the base; a right clamping plate is fixedly arranged on the right side of the top of the object placing plate; a left clamping plate is movably arranged on the left side of the top of the object placing plate; semicircular through grooves are formed in the inner sides of a right clamping plate and a left clamping plate; and a driven roller and a driving roller are in transmission connection through a conveying belt. The cutting wheel can move up and down in the rectangular frame, so that the upper position and thelower position of a cutting gear can be adjusted in the actual operation process, the cutting gear is prevented from being clamped in the cutting part, and a phenomenon that the driving motor is burntis avoided; the left clamping plate and the right clamping plate can clamp and fix the parts to be cut, so that the deviation of the position of the cutting part during the cutting process is prevented, and the cutting quality of the end face of the cutting part is guaranteed.

The invention discloses a medical walking stick with lifting and anti-skid functions. The medical walking stick comprises an axilla support and a supporting column, and also comprises an adjusting mechanism used for adjusting the height of the medical walking stick, and an anti-skid mechanism, wherein the adjusting mechanism is arranged below the axilla support; the supporting column is arranged below the adjusting mechanism; the anti-skid mechanism is arranged on the supporting column; a retractable anti-skid supporting rod is arranged on the anti-skid mechanism; and a control switch used forcontrolling the anti-skid mechanism is arranged on the side surface of the axilla support. The medical walking stick with the lifting and anti-skid functions provided by the invention has the following advantages: the anti-skid function is high; through anti-skid arrangement, the medical walking stick can be automatically folded and unfolded according to different external environments and conditions; the use is flexible and convenient; meanwhile, the height of the walking stick can be adjusted; and high universality is achieved.

The invention discloses a top drive lining type hydraulic drill rod elevator which comprises a main body left hinge and a main body right hinge, wherein rear ends of the main body left hinge and the main body rear hinge are fixedly arranged together through a valve; and a plunger latch is arranged at the front end of the main body left hinge. The top drive lining type hydraulic drill rod elevator is characterized in that a hydraulic cylinder I is arranged at the front end of the main body left hinge; a cylinder body I of the hydraulic cylinder I is fixedly connected with the main body left hinge through a connecting piece I; and a piston rod I of the hydraulic rod I is fixedly connected with the plunger latch. The top drive lining type hydraulic drill rod elevator disclosed by the invention has the advantages that the opening, the closing and the locking of the main body left hinge and the main body right hinge of the hydraulic drive main body are realized; a drill rod is prevented from being clamped in the main body left hinge and the main body right hinge during work; the work efficiency and the safety are improved; and the labor intensity is reduced.

The invention relates to an automobile tire, and particularly discloses a prick-proof automobile tire. The automobile tire comprises a felly, a spoke, a shaft hole and a tire skin, wherein the spoke is fixed in the felly, and the shaft hole is formed in the center of the spoke; the tire skin is sleeved on the felly, an inner tire is arranged between the tire skin and the felly, and the inner wall of the tire skin is fixedly connected with a prick-proof steel ring; a clamping groove is arranged on the tire skin, the prick-proof steel ring is embedded into the clamping groove so as to be fixedly connected with the tire skin, and radiating holes are formed in the prick-proof steel ring. The prick-proof automobile tire provided by the invention has the advantages that the inner tire is prevented from pricking, the time is saved, and the effect of the running process is improved.

The invention provides a coring drilling tool with compressed air as a conveying medium and a scouring medium. The coring drilling tool comprises a coring device and an auxiliary device; the auxiliary device comprises a drill rod and a positioning ring arranged in the drill rod; the coring device comprises a rod body, a penetrating mechanism, a sealing ring and a suspension ring; the rod body is sleeved with the drill rod; a gas circulation channel is formed in the rod body; a gas hole is formed in the side wall of the middle of the rod body and communicates with the gas circulation channel; the penetrating mechanism is arranged in the rod body and used for controlling opening and closing of the gas hole and the gas circulation channel; the rod body is sleeved with the sealing ring, and the sealing ring is used for guaranteeing the sealing performance of the rod body and the drill rod; and the suspension ring is connected to the end of the rod body. In the propelling process of the coring device, the suspension ring abuts against the positioning ring. According to the coring drilling tool, the compressed air serves as the conveying medium and the scouring medium, a rock core and a rock core tube are protected, waste gas of a down-the-hole hammer is prevented from blowing away the rock core, and powder slag is prevented from being accumulated between a hammer head and the rock core tube; and the compressed air serves as the scouring medium, water resources are saved, and the environment is protected.

The invention discloses an elevator system and control method for improving elevator safety. The elevator system comprises an elevator body, a detection assembly and safety tongs, a car of the elevator body is slidably connected with an elevator shaft, a traction machine is rotatably connected with the car and a counterweight through a pull rope, a speed limiter is mounted on one side of a car body, a first photoelectric sensor and a tachometer wheel are arranged on one side of the car body, multiple temperature sensors and multiple smoke sensors of the detection assembly are mounted on different floors of the elevator shaft, and temperature and smoke information of the different floors can be obtained. When the fire requirement is met, a control system drives the traction machine to lowerthe car body at a constant speed and sends distance information of a safety floor to a circuit board, the circuit board calculates the moving distance and triggers the safety tongs to carry out braking, the car body can stop on the safety floor, people can escape, and therefore the safety of people in a fire disaster can be guaranteed.

The invention discloses a grinding assembly of a food waste disposer. The grinding assembly comprises a grinding ring and a grinding disc which cooperate with each other, and the grinding disc is provided with a tool bit capable of being suspended in a limiting mode. The tool bit capable of suspended in the limiting mode can float within a certain range, and when the food waste disposer disposes waste, due to the fact that the tool bit can be suspended, the tool bit can bypass certain large waste or accumulated waste, and the tool bit is prevented from being clamped. According to the grinding assembly, the tool bit adopts a suspensible design structure, so that the tool bit can be effectively prevented from being clamped, and the disposal effect of the food waste disposer is ensured.

The invention belongs to a fixing valve, comprising a strip-shaped nut, a fixing valve shield and a U-shaped combined joint; a first round hole is formed in the top of the fixing valve shield; a second round hole is formed in the bottom of the fixing valve shield; the strip-shaped nut is arranged in the second round hole; the U-shaped joint is arranged in the first round hole; a scale settling device is arranged below the strip-shaped nut. The mode of jointing the U-shaped combined joint and the scale settling device is adopted by the fixing valve, the sundry, sand and scales are blocked in the annular space formed by the U-shaped combined joint and the fixing valve shield, sands and scales are prevented from being accumulated in the inner cavity of the scale settling device, and the fixing valve is prevented from being blocked, so the use period is prolonged and the production efficiency o f an oil field is improved.

The invention provides a bare bobbin conveying device of an automatic winder. The bare bobbin conveying device comprises a gearbox, a flat belt, a flat belt wheel, a lifting belt wheel, a lifting belt and stop blocks on the lifting belt and is characterized in that an arc-shaped guard plate is arranged between the flat belt wheel and the lifting belt wheel; the concave surface of the arc-shaped guard plate faces to the lifting belt wheel and is consistent with the lifting belt wheel in radian; the lower end of the arc-shaped guard plate is positioned under the lifting belt wheel; the upper end of the arc-shaped guard plate is close to the upper-layer flat belt on the flat belt wheel; the upper part of the arc-shaped guard plate is a flat plate which is bent towards to flat belt wheel and is inclined; and the position of the tail end of the flat plate is slightly lower than the upper-layer flat belt on the flat belt wheel. When a bobbin is not stopped, smoothly lifted and carried away by one stop block, the bobbin falls on the arc-shaped guard plate and is supported, lifted and carried away by the next stop block. The bobbin is effectively prevented from being stuck, the bare bobbin conveying efficiency is improved, and the service life of the bare bobbin conveying device is prolonged. The added arc-shaped guard plate is convenient to disassemble and assemble and low in cost.

The invention discloses an anti-collision device for the tail of a large freight vehicle, which comprises a front impact plate, an inclined plate is arranged on the upper end of the front impact plate, a height adjustment mechanism fixed on the tail end of the vehicle beam is arranged on the inner side of the inclined plate, and an inner wall of the front impact plate is provided with The connecting frame, the two ends of the connecting frame are respectively hinged with the limit buffer mechanism located on both sides of the tail of the vehicle frame, and the limit buffer mechanism is located inside the height adjustment mechanism; the limit buffer mechanism includes two bases fixed on the vehicle frame There is a horizontal guide rod between the two bases, a horizontal slide seat is set on the horizontal guide rod, and the horizontal slide seat and the connecting frame are hinged to each other, and the side of the horizontal slide seat is also provided with a horizontal guide rod buffer spring on the The invention has the characteristics of being able to improve the safety protection performance.