Trailer jack

Abstract

The trailer jack comprises a jack body and a quick adjusting mechanism, the jack body comprises an outer cylinder and an inner cylinder which are in transmission connection through a driving mechanism, a plurality of adjusting holes are formed in the outer cylinder in the vertical direction, and supporting parts corresponding to the adjusting holes are arranged on the inner wall of the outer cylinder; the supporting part is used for deepening the depth of the adjusting hole; the quick adjusting mechanism comprises an adjusting seat and a pin lock assembly, the adjusting seat is arranged on the outer cylinder in a sliding mode and used for being connected with a frame, the pin lock assembly is arranged on the adjusting seat, and the pin lock assembly is matched with the adjusting hole to be used for fixing the position of the adjusting seat on the outer cylinder. The lifting height of the frame can be quickly adjusted through the quick adjusting structure, the supporting part is arranged at the corresponding position of the adjusting hole to disperse stress concentrated on the adjusting hole, and the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of jack, especially a trailer jack. BACKGROUND

[0002] The trailer jack is a lifting and supporting device, which is used for vertical supporting between the trailer frame and the ground when the trailer is separated from the towing vehicle, so as to maintain the parking stability of the trailer. The existing trailer jack usually adopts a telescopic mechanism to adjust the supporting height of the trailer. A screw pair composed of a screw rod and a nut is used as the main driving mode of the telescopic mechanism, which has high adjustment accuracy, good self-locking effect and wide application.

[0003] At present, a trailer jack with quick height adjustment is disclosed in Chinese patent application No. CN212292626U, which was published on January 5, 2021. The trailer jack is provided with an axial long guide plate on the side surface of the outer tube. A plurality of locking holes are arranged longitudinally on the guide plate. A sliding frame is mounted on the guide plate. The sliding frame is fixedly connected with the trailer coupling plate. The upper and lower ends of the sliding frame are respectively provided with a connecting plate extending radially along the outer tube. The outer section of the connecting plate is provided with a U-shaped handle. The two fork rods of the handle are respectively embedded into the locking holes, so as to lock the position of the sliding frame on the guide plate.

[0004] During use, the lifting height of the trailer can be quickly adjusted by adjusting the locking position of the sliding frame on the long guide plate.

[0005] According to the above related technology, the long guide plate needs to be fixed on the peripheral side surface of the outer tube by an additional process, so that the long guide plate needs to bear the weight of the trailer. The connection between the long guide plate and the trailer jack is affected by environmental corrosion and other factors, which may cause unstable connection and has great safety risks. UTILITY MODEL CONTENTS

[0006] In order to improve the stability of the trailer jack when supporting the trailer, increase the firmness of the connection between the trailer and the jack, and improve the safety, the utility model provides a trailer jack.

[0007] The utility model provides a trailer jack, adopts the following technical scheme:

[0008] A trailer jack, comprising a jack body and a quick adjustment mechanism, the jack body comprises an outer tube and an inner tube, the outer tube and the inner tube are drivingly connected through a driving mechanism, a plurality of adjustment holes are arranged on one of the side walls of the outer tube in the vertical direction, a support portion is arranged on the inner wall of the outer tube, and the support portion is arranged correspondingly to the adjustment hole; the quick adjustment mechanism comprises an adjustment seat and a pin lock assembly, the adjustment seat is slidably arranged on the outer tube, the adjustment seat is used for connecting the vehicle frame, the pin lock assembly is arranged on the adjustment seat, and the pin lock assembly is locked in cooperation with the adjustment hole.

[0009] By adopting the technical scheme, the adjusting seat is fixed with the outer cylinder by using the pin locking assembly, when the driving mechanism drives the inner cylinder and the outer cylinder to extend or retract, the adjusting seat fixed with the outer cylinder drives the lifting or landing of the vehicle frame, when a large range of quick adjustment of the lifting height of the vehicle frame is needed, firstly, the pin locking assembly is separated from the adjusting hole on the outer cylinder, secondly, the adjusting seat is controlled to slide on the outer cylinder to the height at which the vehicle frame needs to be adjusted, and finally, the locking assembly on the adjusting seat is locked with the adjusting hole on the outer cylinder, so that the lifting height of the vehicle frame can be quickly adjusted, and after the lifting height of the vehicle frame is quickly adjusted by using the adjusting seat, the driving mechanism can be controlled to finely adjust the lifting height of the vehicle frame.

[0010] Thus, by using the pin locking assembly to fix the adjusting seat and the outer cylinder, the lifting height of the vehicle frame can be quickly adjusted, and by directly fixing the adjusting hole on the outer cylinder of the jack, the outer cylinder can directly support the adjusting seat after the adjusting seat bears the gravity of the vehicle, so that the stability of the jack when supporting the vehicle frame is improved; meanwhile, the adjusting hole is directly arranged on the outer cylinder, so that the installation and processing procedures of the excess components are saved, and the processing cost and time are saved; in addition, the support part is arranged at the position corresponding to the adjusting hole, the support part is arranged inside the outer cylinder and corresponds to the adjusting hole to deepen the depth of the adjusting hole, so that when the adjusting hole is fixed with the pin locking assembly, the adjusting hole can disperse the weight applied by the adjusting seat on the adjusting hole on the support part, reduce the stress concentrated on the inner wall of the adjusting hole, and further reduce the probability of the edge deformation of the adjusting hole after the adjusting hole is stressed, so that the stability of the adjusting seat fixed on the outer tube by the pin locking assembly is improved.

[0011] Optionally, the outer cylinder has a polygonal cross section.

[0012] By adopting the technical scheme, when the adjusting seat slides on the outer cylinder, the adjusting seat is arranged as a polygonal structure same as the outer cylinder, and when the outer cylinder and the adjusting seat slide relative to each other, the polygonal structure can play a role of rotation limiting to limit the sliding of the adjusting seat on the outer cylinder along the length direction of the outer cylinder.

[0013] Optionally, one end of the support part is fixedly arranged on the inner wall of the outer cylinder, and the other end of the support part is close to the outer wall of the inner cylinder.

[0014] By adopting the technical scheme, the inner cylinder of the jack is arranged in the inner cavity of the outer cylinder, and when the inner cylinder moves relative to the outer cylinder, the inner cylinder may swing, one end of the support part is close to the outer wall of the inner cylinder, so that the support part plays a role of radial limiting to the inner cylinder, the shaking of the inner cylinder in the outer cylinder is reduced, and the stability between the inner cylinder and the outer cylinder is improved; the support part extends from the outer cylinder to the position close to the outer wall of the inner cylinder, so that the space between the inner cylinder and the outer cylinder can be used to the greatest extent, the support part is arranged to be longer, and when the support part bears the gravity of the adjusting seat, the stress can be more dispersed, and the bearing capacity of the support part is improved.

[0015] Optionally, the support part is in a ring structure, and an inner ring surface of the support part is used as an extension of an inner ring surface of the adjusting hole, and the support part is integrally formed with the outer cylinder.

[0016] By adopting the above technical scheme, when the adjusting seat is fixed on the adjusting hole through the pin locking assembly, the inner ring surface of the support part and the inner ring surface of the adjusting hole jointly support the pin locking assembly, and the weight of the adjusting seat and the weight borne by the adjusting seat are dispersed on the inner ring surface of the adjusting hole and the inner ring surface of the support part, and the integral forming of the support part and the outer cylinder can increase the stability of the connection between the support part and the outer cylinder, so that the support part is more firm.

[0017] Optionally, a pin hole is arranged on the adjusting seat and corresponds to the adjusting hole; the pin locking assembly comprises a spring frame, a pin shaft and an elastic piece, the spring frame is fixedly arranged on the adjusting seat, the spring frame is provided with an assembly hole, the assembly hole corresponds to the pin hole; the pin shaft is sequentially arranged in the assembly hole, the pin hole, the adjusting hole and the support part, one end of the elastic piece is connected to the pin shaft, and the other end of the elastic piece is connected to the spring frame, and the elastic piece has a tendency to insert the pin shaft into the adjusting hole.

[0018] By adopting the above technical scheme, when the locking assembly is separated from the outer cylinder, the pin shaft is pulled out of the adjusting hole of the outer cylinder, and the locking assembly can be separated from the outer cylinder, and at this time, the adjusting seat can slide up and down relative to the outer cylinder; when the locking assembly is fixed to the outer cylinder, the pin hole is aligned with the adjusting hole, the pin shaft is loosened, and the pin shaft moves towards the adjusting hole under the action of the elastic piece, and the pin shaft is inserted into the pin hole and the adjusting hole to fix the locking assembly to the outer cylinder and fix the adjusting seat at a specific height on the outer cylinder. In this way, the pin shaft can be inserted into the pin hole and the adjusting hole under the action of the elastic piece, and the assembly hole can limit the direction of the pin shaft, so that the pin shaft can be aligned with the pin hole and the adjusting hole during sliding, and the use is more convenient; and the arrangement of the elastic piece can realize self-locking function during sliding of the adjusting seat, thereby reducing the risk of falling of the vehicle frame due to fixation of the adjusting seat through the locking assembly.

[0019] Optionally, one end of the pin shaft close to the adjusting hole is further fixedly provided with a stop ring, and the elastic piece is a spring, one end of the spring abuts against the stop ring, and the other end of the spring abuts against the spring frame, and the spring is in a compressed state.

[0020] By adopting the above technical scheme, the spring is sleeved on the pin shaft by abutting against the stop ring and the spring frame, and the spring does not need to be fixed to the pin shaft, so that the spring can be conveniently replaced in the later period; and the arrangement of the stop ring can increase the abutting area of the pin shaft and the spring, so that the spring can be more stably abutted against the pin shaft.

[0021] Optionally, the inner cylinder is a cylindrical structure, and a guide wheel assembly is further fixedly arranged at the bottom of the inner cylinder; the guide wheel assembly is rotationally limited by a rotation limiting assembly and the outer cylinder; the rotation limiting assembly comprises a first limiting ring and a second limiting ring, the first limiting ring is fixedly arranged at the bottom of the outer cylinder, and the second limiting ring is fixedly arranged on the outer wall of the inner cylinder; the first limiting ring and the second limiting ring are correspondingly arranged, and corresponding splines are arranged on the first limiting ring and the second limiting ring.

[0022] By adopting the above technical scheme, the inner cylinder is arranged in a cylindrical structure, so that the inner cylinder can rotate inside the outer cylinder; when the vehicle frame is moved by the guide wheel assembly, the inner cylinder is conveniently rotated to drive the guide wheel assembly to control the rotation direction of the vehicle frame; when the inner cylinder is retracted into the outer cylinder, the first limiting ring and the second limiting ring move towards each other, and when the inner cylinder is completely retracted into the outer cylinder, the splines on the first limiting ring and the second limiting ring are inserted into each other to limit the rotation between the inner cylinder and the outer cylinder; when the guide rail assembly is fixedly arranged at the bottom of the inner cylinder and the jack is retracted on the vehicle frame and moves with the vehicle, the rotation limiting assembly can reduce the swing of the guide wheel assembly and improve the stability; at the same time, the relative movement of the internal parts of the jack is also reduced, and the wear of the parts is reduced.

[0023] Optionally, the spline is in a triangular structure.

[0024] By adopting the above technical scheme, the spline in a triangular structure has the characteristics of automatic alignment; when the inner cylinder is retracted into the outer cylinder, the triangular inclined surfaces of the splines abut against each other, and as the inner cylinder and the outer cylinder are gradually tightened, the first limiting ring and the second limiting ring move towards each other, the splines slide along the triangular inclined surfaces and gradually abut against each other, and the inner cylinder and the outer cylinder rotate relative to each other when the splines slide along the inclined surfaces. By arranging the spline in a triangular structure, the spline can be automatically aligned, and it is not necessary to manually rotate the guide wheel assembly to align the spline, so that the spline is more practical and convenient to use.

[0025] Optionally, the driving mechanism comprises a lead screw, a nut and a thrust bearing, the nut is fixedly arranged on the inner cylinder; a connecting plate is fixedly arranged inside the outer cylinder, the connecting plate is arranged at the top end inside the outer cylinder, the lead screw is rotationally arranged on the connecting plate through the thrust bearing; a oil blocking plate is arranged below the thrust bearing, the oil blocking plate is fixedly arranged inside the outer cylinder, an oil cavity is formed between the connecting plate and the oil blocking plate, and the oil cavity is in communication with the outside of the outer cylinder through an oil injection nozzle.

[0026] By adopting the technical scheme, the screw rod is fixedly arranged on the outer cylinder in rotation through the thrust bearing, when the screw rod drives the inner cylinder and the outer cylinder to relatively stretch and contract through cooperation with the nut, the screw rod and the outer cylinder relatively rotate, the thrust bearing can reduce the friction between the screw rod and the outer cylinder, reduce the abrasion of parts, and make the rotation between the screw rod and the outer cylinder more smooth, further, the oil cavity is arranged for the thrust bearing, and the lubricating oil is added into the oil cavity through the oil injection nozzle, so that the lubricating oil continuously lubricates the thrust bearing, the friction of the thrust bearing can be further reduced, the rotation resistance of the screw rod can be further reduced, and the practical service life of the thrust bearing is prolonged; the oil blocking plate can reduce the overflow of the lubricating oil, and the lubricating oil continuously lubricates the thrust bearing in the oil cavity.

[0027] Optionally, the outer cylinder is provided with a guide plate and a limiting screw, the guide plate is arranged at the bottom of the outer cylinder, and the limiting screw is arranged at the top of the outer cylinder.

[0028] By adopting the technical scheme, the guide plate and the limiting screw protrude from the outer circumferential surface of the outer cylinder, when the adjusting seat slides upward to the limit position, the top of the adjusting seat abuts against the limiting screw protruding from the outer circumferential surface of the outer cylinder; when the adjusting seat slides downward to the limit position, the bottom of the adjusting seat abuts against the guide plate protruding from the outer circumferential surface of the outer cylinder, the sliding range of the adjusting seat on the outer cylinder is limited, and the probability that the adjusting seat slides off the outer cylinder is reduced; when the adjusting seat needs to be removed for maintenance and replacement, the limiting screw only needs to be screwed off from the outer cylinder, and then the adjusting seat can be removed from the outer cylinder.

[0029] Optionally, the outer cylinder is further provided with a limiting column, and the limiting column is used for limiting the inner cylinder in the radial direction.

[0030] By adopting the technical scheme, the limiting column can abut against and support the outer wall of the inner cylinder in the inner cylinder, the swing amplitude of the inner cylinder in the outer cylinder is reduced, the stability of the trailer jack is improved, and the stability of the vehicle frame is improved when the jack supports the vehicle frame.

[0031] In summary, the utility model has at least one of the following beneficial technical effects:

[0032] The adjusting seat is fixed through cooperation of the pin locking assembly and the adjusting hole, the lifting height of the vehicle frame can be quickly adjusted, the adjusting hole is fixedly arranged on the jack, the outer cylinder of the jack directly supports when the adjusting hole bears the gravity of the vehicle, and the stability during support of the vehicle frame is improved; and the adjusting hole is directly arranged on the outer cylinder, and the installation process of the redundant parts is saved, the processing cost and time are saved.

[0033] Support parts are arranged at the corresponding positions of the adjusting holes for deepening the depth of the adjusting holes, when the pin locking assembly is arranged in the adjusting holes to fix the adjusting seat, the adjusting holes and the support parts can simultaneously support the adjusting seat, the stress is dispersed on the adjusting holes and the support parts, the stress concentration on the adjusting holes is reduced, and the probability of the edge deformation of the adjusting holes is caused.

[0034] The guide wheel assembly is arranged at the bottom of the inner cylinder, and the rotating limiting assembly is arranged between the guide wheel assembly and the outer cylinder, when the jack is folded on the frame and moves with the vehicle, the rotating limiting assembly can reduce the swing of the guide wheel assembly and the relative movement of the internal parts of the jack, and reduce the wear of the parts; the rotating limiting assembly limits the rotation of the inner cylinder and the outer cylinder through the triangular gear teeth, and the gear teeth arranged in the triangular structure can realize the automatic alignment of the gear teeth, without manually rotating the guide wheel assembly to align the gear teeth, and the utility is more convenient.

[0035] The screw rod is fixedly arranged in rotation on the outer cylinder through the thrust bearing, and an oil cavity is arranged for the thrust bearing on the outer cylinder, so that the lubricating oil continuously lubricates the thrust bearing, further reduces the friction of the thrust bearing, and in turn reduces the rotation resistance of the screw rod and prolongs the service life of the thrust bearing. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall structure of the embodiment of the application;

[0037] Figure 2 It is Figure 1 A-A sectional view of

[0038] Figure 3 It is Figure 2 B part of the local enlarged view in

[0039] Figure 4 It is Figure 2 Part structure of

[0040] Figure 5 It is Figure 2 C-C sectional view of

[0041] Figure 6 It is a schematic diagram of the inner cylinder structure of the embodiment of the application.

[0042] Explanation of reference signs: 100, outer cylinder; 110, connecting plate; 111, through hole; 120, guide plate; 121, guide hole; 130, adjusting hole; 131, support part; 140, limiting screw; 150, limiting column; 160, oil blocking plate; 170, oil injection nozzle; 180, oil cavity; 200, inner cylinder; 300, driving mechanism; 310, screw rod; 311, threaded section; 312, light shaft section; 313, shaft shoulder; 314, torque wrench joint; 320, nut; 330, thrust bearing; 331, shaft ring; 332, seat ring; 333, rolling body; 400, quick adjusting mechanism; 410, adjusting seat; 411, pin fixing hole; 420, pin locking assembly; 421, spring frame; 422, assembly hole; 423, pin shaft; 424, elastic piece; 425, blocking ring; 500, guide wheel assembly; 600, rotation limiting assembly; 610, first limiting ring; 620, second limiting ring; 630, gear shaping. DETAILED DESCRIPTION

[0043] The applicant finds in use that the screw rod-nut screw pair commonly used for driving the lifting of the trailer jack has the defect of slow speed in large stroke adjustment, that is, the extending height of the trailer jack needs to be matched with the height of the trailer frame by first rotating the screw rod, and then the lifting height of the trailer is adjusted by rotating the screw rod again; therefore, using the quick adjusting device to compensate for the above defects of the screw rod-nut screw pair becomes a major direction of product research and development of the trailer jack, and the quick adjusting mechanism set by the applicant can quickly and widely adjust the lifting height of the trailer jack in cooperation with the adjusting hole set on the jack, and meanwhile, the trailer jack designed by the applicant has the characteristics of stable structure and simple processing technology while solving the above problems.

[0044] The following will be described in detail Figures 1 to 6 The utility model will be further described in detail.

[0045] The utility model embodiment discloses a trailer jack. Referring to Figures 1 to 3 A trailer jack mainly comprises a jack body and a quick adjusting mechanism 400 arranged on the jack body, wherein the jack body comprises an inner cylinder 200, an outer cylinder 100 and a driving mechanism 300, the outer cylinder 100 is arranged outside the inner cylinder 200 and drives the inner cylinder 200 and the outer cylinder 100 to relatively stretch and shrink through the driving mechanism 300, the quick adjusting mechanism 400 comprises an adjusting seat 410 slidably arranged on the outer cylinder 100 and a pin locking assembly 420 for fixing the adjusting seat 410 and the outer cylinder 100, wherein the adjusting seat 410 is used for being connected with the frame of the trailer, and after the pin locking assembly 420 is loosened to release the fixing of the adjusting seat 410 and the outer cylinder 100, the adjusting seat 410 can slide on the outer cylinder 100, and the lifting height of the frame is adjusted.

[0046] Referring to Figure 1The outer cylinder 100 is a tubular structure with a rectangular cross section, a connecting plate 110 is fixed on the top of the outer cylinder 100, and a guide plate 120 is fixed on the bottom of the outer cylinder 100, a through hole 111 is formed on the connecting plate 110, and a guide hole 121 is formed on the guide plate 120, the through hole 111 and the guide hole 121 are coaxially arranged in the vertical direction.

[0047] In this embodiment, the outer cylinder 100 is a rectangular tube composed of four side walls, and in other embodiments, the outer cylinder 100 can also be a rectangular tube composed of five or more side walls. By setting the cross section of the outer cylinder 100 as a polygonal structure, the rotation of the adjusting seat 410 mounted on the outer cylinder 100 can be limited.

[0048] Referring to Figure 1 and Figure 6 The inner cylinder 200 is a tubular structure with a circular cross section, and a guide wheel assembly 500 is connected to the bottom of the inner cylinder 200; the inner cylinder 200 extends into the inner cavity of the outer cylinder 100 from below through the guide hole 121 on the guide plate 120, and the inner cylinder 200 can slide along the axial direction of the outer cylinder 100 and can rotate relative to the outer cylinder 100, and the top of the inner cylinder 200 is connected to the outer cylinder 100 through a driving mechanism 300.

[0049] Referring to Figure 2 The driving mechanism 300 includes a lead screw 310, a nut 320, and a thrust bearing 330, the nut 320 is fixed on the top of the inner cylinder 200, the lead screw 310 is coaxially arranged with the inner cylinder 200, specifically the lead screw 310 includes an axial threaded segment 311 and a light shaft segment 312, the threaded segment 311 of the lead screw 310 is threadedly connected with the nut 320; the light shaft segment 312 of the lead screw 310 extends out of the outer cylinder 100 through the through hole 111 on the connecting plate 110, and the light shaft segment 312 of the lead screw 310 is rotatably mounted on the connecting plate 110 through the thrust bearing 330, and a torque wrench joint 314 is provided on the top of the light shaft segment 312.

[0050] In use, the torque wrench joint 314 is connected by a matching wrench and a torque is applied, the lead screw 310 is forced to rotate, and under the threaded connection, the lead screw 310 moves axially relative to the nut 320, thereby synchronously driving the outer cylinder 100 and the inner cylinder 200 to slide relative to each other, realizing the telescopic function of the inner cylinder 200 and the outer cylinder 100.

[0051] Referring to Figure 3At the abutment of the threaded section 311 and the light axle section 312, an axle shoulder 313 is formed, a thrust bearing 330 is sleeved on the light axle section 312 of the screw rod 310, the axle ring 331 of the thrust bearing 330 is pressed on the axle shoulder 313, the seat ring 332 of the thrust bearing 330 is pressed on the connecting plate 110 of the outer cylinder 100, and the rolling body 333 is rollingly arranged between the axle ring 331 and the seat ring 332, so that when the screw rod 310 and the outer cylinder 100 rotate relative to each other, the rotating resistance of the screw rod 310 can be reduced through the thrust bearing 330.

[0052] With reference to Figure 3 In order to further reduce the rotating resistance of the screw rod 310 and improve the lubrication efficiency of the thrust bearing 330, an oil blocking plate 160 is arranged in the outer cylinder 100 corresponding to the axle ring 331 of the thrust bearing 330, the oil blocking plate 160, the connecting plate 110 and the outer cylinder 100 form an oil cavity 180, an oil injection nozzle 170 is arranged on the side wall of the outer cylinder 100 corresponding to the oil cavity 180, the oil cavity 180 is used for external communication of the outer cylinder 100, and lubricating oil is injected into the oil cavity 180 through the oil injection nozzle 170 for continuous lubrication of the thrust bearing 330, which can further reduce the rotating resistance of the screw rod 310 and prolong the service life of the thrust bearing 330.

[0053] With reference to Figure 1 and Figure 4 The quick adjustment mechanism 400 includes an adjustment seat 410 and a pin locking assembly 420, and eight adjustment holes 130 are uniformly distributed along the length direction of the outer cylinder 100 on the cylinder wall of the outer cylinder 100 away from the inner cylinder 200; the adjustment seat 410 is used for being connected with the frame of the trailer, the adjustment seat 410 is sleeved on the outer side of the outer cylinder 100 and slides along the outer wall of the outer cylinder 100, and a pin fixing hole 411 is arranged on the adjustment seat 410; the pin locking assembly 420 is arranged on the adjustment seat 410, specifically, the pin locking assembly 420 includes a spring frame 421, at least one pin shaft 423 and at least one spring, the spring frame 421 is fixed on the adjustment seat 410, an assembly hole 422 is formed in the spring frame 421, the assembly hole 422 is arranged corresponding to the pin fixing hole 411, the pin shaft 423 is arranged in the assembly hole 422, a stop ring 425 is arranged at the position of the pin shaft 423 between the assembly hole 422 and the pin fixing hole 411, the spring is sleeved on the pin shaft 423, one end of the spring is pressed on the spring frame 421 and the other end of the spring abuts against the stop ring 425, the spring is in a compressed state, the pin shaft 423 has a tendency to move towards the pin fixing hole 411, and the pin locking assembly 420 realizes the limiting of the adjustment seat 410 by controlling the pin shaft 423 to pass through the pin fixing hole 411 and the corresponding adjustment hole 130.

[0054] With reference to Figure 4In the embodiment, the adjusting hole 130 is directly formed on the wall of the outer cylinder 100. In order to improve the connecting strength of the adjusting hole 130, the wall of the adjusting hole 130 on one side of the inner wall of the outer cylinder 100 is treated by flanging process, so that the adjusting hole 130 forms an annular supporting part 131 with the same diameter as the adjusting hole 130 on one side of the inner wall of the outer cylinder 100. When the pin shaft 423 is inserted into the adjusting hole 130, the inner wall of the adjusting hole 130 and the inner wall of the annular supporting part 131 simultaneously support the pin shaft 423, which can effectively disperse the stress concentrated on the adjusting hole 130.

[0055] The adjusting hole 130 is directly formed on the side wall of the outer cylinder 100, which saves the process step of adding a long guide plate on the outer wall of the outer cylinder 100, and can save processing time. Compared with the integral hole structure of the application, other connection methods have the risk of unstable connection or even failure, such as corrosion of the welding seam, poor riveting and gluing strength, easy to fall off, easy to fail in threaded connection, etc.

[0056] Referring to Figure 4 and Figure 5 In the embodiment, in order to reserve a position for the cooperation between the pin lock assembly 420 and the outer cylinder 100, the outer wall of the inner cylinder 200 is only close to three inner walls of the outer cylinder 100, so that the outer cylinder 100 can only support the inner cylinder 200 in three directions. Specifically, in the embodiment, the outer wall of the inner cylinder 200 and the three inner walls of the outer cylinder 100 each have a 5mm assembly gap, so that when the outer cylinder 100 moves relative to the inner cylinder 200, the outer cylinder 100 can provide radial limiting action to the inner cylinder 200; in order to leave a cooperation space for the pin shaft 423 to be inserted into the adjusting hole 130, the inner wall of the side of the adjusting hole 130 of the outer cylinder 100 is spaced apart from the outer wall of the inner cylinder 200, which limits the radial limiting action of the outer cylinder 100 to the inner cylinder 200; in order to solve this problem, in the embodiment, the supporting part 131 of the adjusting hole 130 extends towards the outer wall of the inner cylinder 200, so that when the inner cylinder 200 shakes inside the outer cylinder 100, the end of the supporting part 131 abuts against the outer wall of the inner cylinder 200 to strengthen the radial limiting action to the inner cylinder 200.

[0057] Referring to Figure 5 and Figure 6 In other embodiments, the inner cylinder 200 can be further radially limited by the following method, that is, at least one limiting column 150 is arranged on the guide plate 120, the limiting column 150 is arranged in the inner cavity of the outer cylinder 100, and the limiting column 150 is tangent to the outer wall of the inner cylinder 200 and the inner wall of the outer cylinder 100 respectively; when the inner cylinder 200 is forced to swing radially, the outer wall of the inner cylinder 200 is in close contact with the limiting column 150, the limiting column 150 is supported radially by the outer cylinder 100, and the occurrence of radial swinging of the inner cylinder 200 is limited, preferably, the limiting column 150 is symmetrically provided with two, so that the limiting range of the limiting column 150 to the radial swinging trend of the inner cylinder 200 is wider.

[0058] With reference to Figure 2 In order to prevent the adjusting seat 410 from sliding off the outer cylinder 100, a limiting screw 140 is arranged on the side wall of the outer cylinder 100 near the top, the limiting screw 140 protrudes outward from the outer wall of the outer cylinder 100 to form a protruding structure, and the guide plate 120 at the bottom of the outer cylinder 100 extends outward from the outer cylinder 100 to form a protruding edge relative to the outer wall of the outer cylinder 100, so that the limiting screw 140 and the guide plate 120 can limit the adjusting seat 410 at the top and bottom of the outer cylinder 100, respectively.

[0059] With reference to Figure 1 In order to limit the relative angle of the guide wheel assembly 500 and the outer cylinder 100, in the present embodiment, a rotation limiting assembly 600 is arranged between the bottom of the outer cylinder 100 and the inner cylinder 200, the rotation limiting assembly 600 is divided into a first limiting ring 610 and a second limiting ring 620 that cooperate with each other, the first limiting ring 610 is fixed on the guide plate 120 of the outer cylinder 100, and the second limiting ring 620 is fixedly arranged on the outer wall of the inner cylinder 200, the mating surfaces of the first limiting ring 610 and the second limiting ring 620 are respectively uniformly distributed with insert teeth 630 that can be inserted and fitted, the first limiting ring 610 and the second limiting ring 620 can limit the relative angle of the outer cylinder 100 and the guide wheel assembly 500 through the combination of different insert teeth 630, which can reduce the random swinging of the guide wheel assembly 500 when it is retracted, and can also set and lock the steering angle when the trailer is adjusted in direction, the guide wheel assembly 500 is limited by the insert teeth 630, and the limiting range is wider and the limiting position is more flexible.

[0060] In the present embodiment, the insert teeth 630 uniformly distributed in a ring shape on the mating surfaces of the first limiting ring 610 and the second limiting ring 620 are in a triangular structure, the triangular insert teeth 630 have the characteristics of automatic matching and locking when being inserted, so that the abutting position of the guide wheel assembly 500 or the inner cylinder 200 does not need to be manually adjusted when the insert teeth 630 are abutted, which is more convenient in use; in other embodiments, the insert teeth 630 can also be structures with inclined surfaces or other equivalent types of guide surfaces, such as trapezoidal, arc-shaped, and wavy cross sections.

[0061] The embodiment of the utility model discloses a trailer jack's implementation principle is: when using first pull pin shaft 423, make pin shaft 423 move to the direction of overcoming spring elasticity, until pin shaft 423 extracts adjustment hole 130, adjustment seat 410 and outer tube 100 slide relative to each other at this moment;Secondly adjust the relative position of adjustment seat 410 and outer tube 100, select the adjustment hole 130 corresponding with pin fixed hole 411, make the guide wheel assembly 500 close to the ground;Thirdly loosen pin shaft 423, pin shaft 423 passes through pin fixed hole 411 and inserts in the corresponding adjustment hole 130 under the spring elasticity, lock the relative position of adjustment seat 410 and outer tube 100;Finally, through the drive mechanism 300 fine adjustment inner tube 200's length of extension, until guide wheel assembly 500 ground, and through drive mechanism 300 adjustment inner tube 200's length of extension, realize the support adjustment of trailer frame height.

[0062] Summarized above, when pin shaft 423 inserts in adjustment hole 130, the inner wall of adjustment hole 130 and the inner wall of support part 131 support pin shaft 423 simultaneously, reduce stress concentration on adjustment hole 130, lead to the probability of adjustment hole 130 force edge deformation;When inner tube 200 contracts in outer tube 100, rotating limiting assembly 600 can limit the relative angle of guide wheel assembly 500 and outer tube 100, and through the triangular pin gear 630, make rotating limiting assembly 600 have the characteristics of automatic locking when inserting, more convenient to use;Adopt fast adjustment mechanism 400 to replace the screw rod 310 - nut 320 screw pair of drive mechanism 300 through large stroke telescopic to adjust the mode of guide wheel assembly 500 landing, can improve the frame height adjustment efficiency greatly.

[0063] The above are the preferred embodiments of the utility model, not limited to the protection scope of the utility model, therefore: all equivalent changes made according to the structure, shape, principle of the utility model should be covered in the protection scope of the utility model.

Claims

1. A trailer jack, comprising a jack body and a quick adjustment mechanism (400), the jack body comprising an outer cylinder (100) and an inner cylinder (200), the outer cylinder (100) and the inner cylinder (200) being drivingly connected by a driving mechanism (300), characterized in that: a plurality of adjustment holes (130) are arranged on one side wall of the outer cylinder (100) in a vertical direction, and a support portion (131) is arranged on the inner wall of the outer cylinder (100) and corresponds to the adjustment hole (130); the quick adjustment mechanism (400) comprises an adjustment seat (410) and a pin lock assembly (420), the adjustment seat (410) is slidingly arranged on the outer cylinder (100), the adjustment seat (410) is used for connecting a vehicle frame, and the pin lock assembly (420) is arranged on the adjustment seat (410) and cooperates with the adjustment hole (130) to be locked. One end of the support portion (131) is fixedly arranged on the inner wall of the outer cylinder (100), and the other end of the support portion (131) is close to the outer wall of the inner cylinder (200).

2. A trailer jack as claimed in claim 1 wherein: The support portion (131) has a ring structure, an inner ring surface of the support portion (131) is used as an extension of an inner ring surface of the adjustment hole (130), and the support portion (131) is integrally formed with the outer cylinder (100).

3. A trailer jack as claimed in claim 2 wherein: A pin hole (411) is arranged on the adjustment seat (410) and corresponds to the adjustment hole (130); 4. A trailer jack as claimed in any one of claims 1 to 3, wherein: the pin lock assembly (420) comprises a spring frame (421), a pin shaft (423) and an elastic member (424), the spring frame (421) is fixedly arranged on the adjustment seat (410), an assembly hole (422) is arranged on the spring frame (421) and corresponds to the pin hole (411); the pin shaft (423) is sequentially arranged in the assembly hole (422), the pin hole (411), the adjustment hole (130) and the support portion (131), one end of the elastic member (424) is connected to the pin shaft (423), the other end of the elastic member (424) is connected to the spring frame (421), and the elastic member (424) has a tendency to insert the pin shaft (423) into the adjustment hole (130). One end of the pin shaft (423) close to the adjustment hole (130) is further fixedly provided with a stop ring (425), the elastic member (424) is a spring, one end of the spring abuts against the stop ring (425), the other end of the spring abuts against the spring frame (421), and the spring is in a compressed state.

5. A trailer jack as claimed in claim 4 wherein: The inner cylinder (200) is a cylinder, and a guide wheel assembly (500) is further fixedly arranged at the bottom of the inner cylinder (200); the guide wheel assembly (500) is rotationally limited by a rotation limiting assembly (600) and the outer cylinder (100).

6. A trailer jack as claimed in any one of claims 1 to 3, wherein: ​ The rotation limiting assembly (600) comprises a first limiting ring (610) and a second limiting ring (620), the first limiting ring (610) is fixedly arranged at the bottom of the outer cylinder (100), the second limiting ring (620) is fixedly arranged on the outer wall of the inner cylinder (200), the first limiting ring (610) and the second limiting ring (620) are correspondingly arranged, and the first limiting ring (610) and the second limiting ring (620) are provided with corresponding pin gears (630).

7. A trailer jack according to claim 6 wherein: The pin gear (630) is a triangular structure.

8. A trailer jack as claimed in any one of claims 1 to 3, wherein: The driving mechanism (300) comprises a lead screw (310), a nut (320) and a thrust bearing (330), the nut (320) is fixedly arranged on the inner cylinder (200); The outer cylinder (100) is internally fixedly provided with a connecting plate (110), the connecting plate (110) is arranged at the top end in the inner cylinder (100), the lead screw (310) is rotatably arranged on the connecting plate (110) through the thrust bearing (330); The thrust bearing (330) is provided below a grease blocking plate (160), the grease blocking plate (160) is fixedly arranged in the outer cylinder (100), an oil cavity (180) is formed between the connecting plate (110) and the grease blocking plate (160), and the oil cavity (180) is communicated with the outside of the outer cylinder (100) through an oil injection nozzle (170).

9. A trailer jack as claimed in any one of claims 1 to 3, wherein: The outer cylinder (100) is provided with a guide plate (120) and a limiting screw (140), the guide plate (120) is arranged at the bottom of the outer cylinder (100), and the limiting screw (140) is arranged at the top of the outer cylinder (100).

10. A trailer jack as claimed in any one of claims 1 to 3, wherein: The outer cylinder (100) is further provided with a limiting column (150) inside, and the limiting column (150) is used for radially limiting the inner cylinder (200).

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