CN217076787U - Small-size single cantilever vehicle-mounted loop wheel machine - Google Patents

Abstract

The utility model provides a small-size single cantilever vehicle-mounted crane, the setting is close to locomotive one end at the freight train packing box, including the pneumatic cylinder, the aircraft nose, davit and drive mechanism, the pneumatic cylinder handstand sets up, the piston rod of pneumatic cylinder passes the packing box bottom plate and articulates with the car girder, the cover is equipped with solid fixed ring on the pneumatic cylinder, gu fixed ring articulates with the packing box, aircraft nose level pivoted sets up in the pneumatic cylinder upper end, davit one end is articulated with the aircraft nose, the davit can be followed around the freight train and overturned, drive mechanism sets up on the davit, the aircraft nose includes the front bezel, the back plate, bottom plate and two curb plates, the bottom plate level sets up, two curb plates set up at the bottom plate both ends, back plate and front bezel are along the gliding setting of vertical direction at the both ends of two curb plates, the front bezel is located and is close to freight train one end at the bottom plate, the davit articulates between two curb plates, it is big to have solved traditional vehicle-mounted crane size, the structure is complicated, with high costs, And the like, and the driving safety of the vehicle is easily influenced, the cargo loading efficiency is improved, and the labor intensity is reduced.

Description

Small-size single cantilever vehicle-mounted loop wheel machine

Technical Field

The utility model relates to a jack-up hoist and mount technical field particularly, relates to a small-size single cantilever vehicle-mounted loop wheel machine.

Background

Along with the improvement of living standard and the development of the Internet of things, more and more people enter the logistics transportation industry, one small truck can be applied for transporting goods at home, the goods loading and unloading of a plurality of small transportation vehicles need to be completed by workers, the goods loading and unloading efficiency of manual goods loading and unloading is low, and safety accidents are easy to happen. For some heavy goods, additional hoisting equipment or a forklift is needed to complete loading and unloading of the goods, and transportation cost is increased. The truck-mounted crane mechanism of the large transport vehicle on the market at present has high manufacturing cost, complex structure and larger volume, while the truck-mounted crane mechanism of the small transport vehicle needs smaller crane arm size, and the vehicle body structure is originally small, so that the truck-mounted crane of the large transport vehicle cannot be completely adopted. Therefore, it is necessary to design a truck-mounted crane suitable for a small-sized transportation vehicle, which has a simple structure and low cost.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a small-size single cantilever vehicle-mounted loop wheel machine, it has solved big, the structure is complicated, with high costs, the scheduling problem of travelling safety that the vehicle was influenced easily to traditional vehicle-mounted loop wheel machine size to improve the efficiency of goods loading, reduced intensity of labour.

The embodiment of the utility model discloses a realize through following technical scheme: a small-sized single-cantilever crane with a truck is arranged at one end, close to a truck head, of a truck container and comprises a hydraulic cylinder, a truck head, a boom and a traction mechanism, wherein the hydraulic cylinder is arranged in an inverted mode, a piston rod of the hydraulic cylinder penetrates through a bottom plate of the truck container and is hinged with a truck beam, a fixing ring is sleeved on a cylinder barrel of the hydraulic cylinder and is hinged with the truck body, the cylinder barrel of the hydraulic cylinder is arranged in the fixing ring in a sliding mode, the truck head is arranged at the upper end of the hydraulic cylinder in a horizontally rotating mode, one end of the boom is hinged with the truck head, the boom can turn back and forth along the truck, and the traction mechanism is arranged on the boom;

the machine head comprises a front plate, a rear plate, a bottom plate and two side plates, wherein the bottom plate is horizontally arranged, the two side plates are vertically arranged at the left end and the right end of the bottom plate, the rear plate and the front plate are arranged at the two ends of the side plates in a sliding mode along the vertical direction, the front plate is located at one end, close to the head of the truck, of the bottom plate, a rotating shaft is rotatably arranged between the two side plates, and a lifting arm is sleeved on the rotating shaft.

The front plate with the interval is provided with a plurality of first springs between the bottom plate, the both ends of first spring respectively with front plate and bottom plate are connected, the back plate with the interval is provided with a plurality of second springs between the bottom plate, the both ends of second spring respectively with back plate and bottom plate are connected.

Furthermore, the davit is close to pivot one end is provided with the drag link, the front bezel with all seted up the through-hole on the back plate, the through-hole is located the rotation route of drag link.

Further, the thickness and width of the rear plate are the same as those of the front plate, and the length of the rear plate is longer than that of the front plate.

Further, the spout has all been seted up at two ends of curb plate, the both ends of front bezel all are provided with first slider, the both ends of back plate all are provided with the second slider, first slider with the second slider slides respectively and arranges in the spout at curb plate both ends.

The upper end of the rotary cylinder is sealed, the rotary cylinder is sleeved at the upper end of the hydraulic cylinder, the bottom plate is sleeved at the upper end of the rotary cylinder, a limiting shaft is vertically arranged at the top of the hydraulic cylinder and penetrates through the rotary cylinder, a pushing bearing is sleeved on the limiting shaft, and two ends of the pushing bearing are respectively abutted against the rotary cylinder and the hydraulic cylinder;

the hydraulic cylinder barrel is sleeved with a large bearing, and the outer end of the large bearing is abutted to the inner wall of the lower end of the rotating cylinder.

Furthermore, the lower end of the rotating cylinder is provided with a movable limiting block, two static limiting blocks are arranged on the opposite sides of the fixing ring, and the static limiting blocks are located on a rotating path of the movable limiting blocks.

The suspension arm is provided with a plurality of support holes at intervals, one end of the support rod is hinged with the lower end of the rotary cylinder, and the other end of the support rod is connected with the support holes.

Further, drive mechanism includes capstan winch, first pulley, second pulley and lifting hook, the davit includes first cantilever and second cantilever, first cantilever one end with the aircraft nose is articulated, be equipped with smooth chamber on the first cantilever, the second cantilever slides and arranges in smooth intracavity, first pulley sets up first cantilever is kept away from aircraft nose one end, the second pulley sets up the second cantilever is kept away from aircraft nose one end, the noose of capstan winch pass first pulley and second pulley in proper order with the lifting hook is connected.

The truck head protection device is characterized by further comprising a protection seat, wherein the protection seat is arranged at the top of the truck head, a U-shaped groove is formed in the protection seat, and the U-shaped groove is located on the rotation path of the first cantilever.

Furthermore, grooves are formed in the front plate and the rear plate, rubber pads are arranged in the grooves, and the grooves are located on the rotation path of the suspension arm.

The utility model discloses technical scheme has following advantage and beneficial effect at least:

the utility model relates to a rationally, simple structure, a small-size single cantilever vehicle-mounted loop wheel machine sets up and is close to locomotive one end at the freight train packing box, including pneumatic cylinder, aircraft nose, davit and drive mechanism, does not influence the vehicle performance of traveling basically. The problem that the driving performance of a vehicle is influenced after an existing crane is installed can be solved, the occupied space of a vehicle cargo compartment is extremely small, the loading space of the cargo compartment is not influenced basically, the labor intensity can be reduced when cargoes are loaded, the labor cost is saved, the working efficiency is improved, the normal driving of the vehicle is not influenced, the cargo loading efficiency is improved, and the labor intensity is reduced.

Because when the suspension arm is overturned forwards and backwards, when the suspension arm falls to abut against the front plate or the rear plate, great impact force is easy to generate, the suspension arm and the rotating shaft are not friendly, and are easy to damage, the front plate and the rear plate are arranged between the two side plates in a sliding way, and the bottom parts of the front plate and the rear plate are respectively provided with the first spring and the second spring, so that when the suspension arm rotates to abut against the front plate and the rear plate, the suspension arm can be buffered by the first spring and the second spring respectively, and simultaneously the resistance rod is matched, when the suspension arm is overturned to one end of the vehicle head to abut against the front plate, the resistance rod enters into the through hole of the rear plate to lift the rear plate upwards, at the moment, the suspension arm is subjected to deceleration buffering by compressing the plurality of first springs, and is pulled by the plurality of second springs to jointly slow down the impact of the suspension arm on the front plate, and when the suspension arm is rotated to one side of a cargo box, the plurality of first springs and the plurality of second springs are restored to deform, and certain elastic force can be provided, the lifting of the suspension arm is facilitated, the manual adjustment of the overturning of the suspension arm is facilitated, and the same effect is achieved when the suspension arm is abutted to the rear plate in the same way.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic front view of a small single-cantilever crane mounted on a vehicle provided by the present invention;

fig. 2 is a left side view schematically illustrating a small single-cantilever crane mounted on a vehicle provided by the present invention;

fig. 3 is a schematic view of the internal structures of the machine head and the rotary cylinder when the boom of the small single-cantilever crane provided by the utility model is retracted to one side of the machine head;

fig. 4 is a schematic view of the internal structure of the machine head and the rotary drum when the boom of the small single-boom lorry-mounted crane provided by the utility model works;

icon: 1. the cargo box comprises a cargo box body, 101, a cargo box bottom plate, 2, a vehicle head, 3, a vehicle girder, 4, a hydraulic cylinder, 5, a machine head, 51, a front plate, 52, a rear plate, 53, a bottom plate, 54, side plates, 55, a rotating shaft, 56, a through hole, 57, a sliding chute, 58, a first sliding block, 59, a second sliding block, 510, a groove, 6, a suspension arm, 61, a first cantilever, 62, a second cantilever, 63, a sliding cavity, 64, a strand cable, 7, a fixing ring, 8, a first spring, 9, a second spring, 10, a resistance rod, 11, a rotating cylinder, 12, a limiting shaft, 13, a jacking bearing, 14, a large bearing, 15, a movable limiting block, 16, a static limiting block, 17, a supporting rod, 18, a supporting hole, 19, a winch, 20, a first pulley, 21, a second pulley, 22, a lifting hook, 23, a protecting seat, 24, a U-shaped groove, 25 and a rubber pad.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

Referring to fig. 1 to 4, the embodiment provides a small single-cantilever crane with a truck, which is arranged at one end of a truck cargo box 1 close to a truck head 2, and comprises a hydraulic cylinder 4, a machine head 5, a boom 6 and a traction mechanism, wherein the hydraulic cylinder 4 is arranged in an inverted manner, a piston rod of the hydraulic cylinder 4 penetrates through a cargo box bottom plate 101 to be hinged with a truck girder 3, a cylinder barrel of the hydraulic cylinder 4 is sleeved with a fixing ring 7, the fixing ring 7 is hinged with the truck cargo box 1, the cargo box 1 at the hinged position needs to be additionally reinforced, the cylinder barrel of the hydraulic cylinder 4 is slidably arranged in the fixing ring 7, the machine head 5 is horizontally and rotatably arranged at the upper end of the hydraulic cylinder 4, one end of the boom 6 is hinged with the machine head 5, the boom 6 can turn back and forth along the truck, and the traction mechanism is arranged on the boom 6;

the machine head 5 comprises a front plate 51, a rear plate 52, a bottom plate 53 and two side plates 54, wherein the bottom plate 53 is horizontally arranged, the two side plates 54 are vertically arranged at the left end and the right end of the bottom plate 53, the rear plate 52 and the front plate 51 are arranged at the two ends of the two side plates 54 in a sliding mode along the vertical direction, the front plate 51 is positioned at one end, close to the head 2 of the truck, of the bottom plate 53, a rotating shaft 55 is rotatably arranged between the two side plates 54, and one end of the suspension arm 6 is sleeved on the rotating shaft 55.

As shown in fig. 1-4, in the specific implementation, the truck-mounted crane needs to punch a hole on the bottom plate of the cargo compartment at the position close to the rail at the longitudinal front edge of the cargo compartment 1 and at the transverse center position, the distance between the outer edge of the crane upright column (hydraulic cylinder 4) and the edge of the cargo compartment 1 is about 5mm, and the aperture is 80-140 mm (the aperture is based on the smooth penetration of the piston rod of the hydraulic cylinder 4). When the hydraulic cylinder 4 is installed, the piston rod of the hydraulic cylinder 4 is downward, the cylinder barrel is upward, the piston rod of the hydraulic cylinder 4 penetrates through the bottom plate 101 of the cargo compartment, a steel pipe penetrates through a connecting hole at the head of the piston rod, two ends of the steel pipe are respectively fixed on two parallel vehicle girders 3 of a vehicle, and the central line of the hydraulic cylinder 4 is superposed with the central lines of the two parallel vehicle girders 3 of the vehicle. The suspension arm 6 hinged on the machine head is turned back and forth, so that the suspension arm 6 is contracted and placed on the vehicle head when not practical, the occupation of the crane on the space of the vehicle cargo compartment 1 is reduced, and the influence of the installation of the crane on the vehicle running safety is reduced to the minimum. The bottom dead center of the cylinder barrel is flush with the bottom of the cargo compartment, the top dead center is determined according to the working requirement, the lifting stroke is 500-1000 mm, the total length of the hydraulic cylinder 4 is from the double parallel girders at the bottom of the vehicle to the top of the passenger compartment, the maximum length can reach 100mm above the top of the passenger compartment, and the wall thickness of the cylinder barrel is 10-15 mm.

The nose 5 is mainly formed by enclosing a front plate 51, a rear plate 52, a bottom plate 53 and two side plates 54 into a square brick shape (the shape can be adjusted as required), holes are formed in the two side plates 54, a rotating shaft 55 is rotatably arranged, one end of the suspension arm 6 is sleeved on the rotating shaft 55, and then the suspension arm 6 can rotate back and forth.

Side plate 54: two steel plates with the length and width of 300 x 300mm (or 200 x 300mm), the width of which is equal to the diameter of the rotary drum 11, and the thickness of which is 10-15 mm.

Front plate 51: the rectangular steel plate is slightly smaller than the outer diameter of the distance between the two side plates 54 in width, 50-100mm in length, is used for supporting the cantilever when a vehicle runs and preventing the cantilever and the winch from colliding with the top of a passenger cabin, and is as thick as the side plates.

The thickness and width of the rear plate 52 are the same as those of the front plate 51, and the length of the rear plate 52 is longer than that of the front plate 51.

Rear plate 52: the rectangular steel plate is slightly smaller than the outer diameter of the distance between the two side plates 54 in width, is 100mm long and 200mm long, is used for supporting the suspension arm 6 when the crane works, and when the supporting rod 17 is used, the suspension arm and the horizontal plane form an angle of 30 degrees through the backing of the rear plate 52, and when the supporting rod 17 is not used, the suspension arm 6 and the horizontal plane form an angle of 45-60 degrees and have the same thickness as the side plates.

A plurality of first springs 8 are arranged between the front plate 51 and the bottom plate 53 at intervals, two ends of each first spring 8 are respectively connected with the front plate 51 and the bottom plate 53, a plurality of second springs 9 are arranged between the rear plate 52 and the bottom plate 53 at intervals, and two ends of each second spring 9 are respectively connected with the rear plate 52 and the bottom plate 53.

One end of the suspension arm 6 close to the rotating shaft 55 is provided with a resistance bar 10, through holes 56 are respectively formed on the front plate 51 and the rear plate 52, and the through holes 56 are positioned on the rotating path of the resistance bar 10.

Sliding grooves 57 are formed in two ends of the two side plates 54, first sliding blocks 58 are arranged at two ends of the front plate 51, second sliding blocks 59 are arranged at two ends of the rear plate 52, and the first sliding blocks 58 and the second sliding blocks 59 are arranged in the sliding grooves 57 at two ends of the side plates 54 in a sliding mode respectively.

As shown in fig. 3 and 4, in the specific implementation, when the boom 6 is turned back and forth, when the boom falls down to abut against the front plate 51 or the rear plate 52, an extremely large impact force is easily generated, the boom 6 and the rotating shaft 55 are not friendly, and are very easy to damage, the front plate 51 and the rear plate 52 are slidably arranged between the two side plates 54, and the first spring 8 and the second spring 9 are respectively arranged at the bottom of the front plate 51 and the bottom of the rear plate 52, so that when the boom 6 is turned to abut against the front plate 51 and the rear plate 52, the front plate 51 and the rear plate 52 can be buffered by the first spring 8 and the second spring 9 respectively, and the resistance rod 10 is matched, when the boom 6 is turned to abut against one end of the vehicle head 2 and the front plate 51, the resistance rod 10 enters into the through hole 56 of the rear plate 52 to pick up the rear plate 52, at this time, the boom 6 is decelerated and buffered by not only compressing the first springs 8, but also pulling the second springs 9, so as to slow down the impact of the boom to the front plate 51, simultaneously when lifting boom 6 and rotating to packing box 1 one side, a plurality of first springs 8 and a plurality of second spring 9 can also provide certain elasticity when resumeing deformation, help lifting of boom 6, made things convenient for the upset of manual regulation cantilever 6, like this when boom 6 and back plate 52 butt, also have same effect.

The hydraulic cylinder is characterized by further comprising a rotating cylinder 11, the upper end of the rotating cylinder 11 is sealed, the rotating cylinder 11 is sleeved at the upper end of the hydraulic cylinder 4, the bottom plate 53 is sleeved at the upper end of the rotating cylinder 11, a limiting shaft 12 is vertically arranged at the top of the hydraulic cylinder 4, the limiting shaft 12 penetrates through the rotating cylinder 11, a pushing bearing 13 is sleeved on the limiting shaft 12, and two ends of the pushing bearing 13 are respectively abutted against the rotating cylinder 11 and the hydraulic cylinder 4;

the lower end of the rotating cylinder 11 is provided with a movable limiting block 15, the opposite side of the fixing ring 7 is provided with two static limiting blocks 16, and the static limiting blocks 16 are positioned on the rotating path of the movable limiting block 15.

The cylinder barrel of the hydraulic cylinder 4 is sleeved with a large bearing 14, and the outer end of the large bearing 14 is abutted to the inner wall of the lower end of the rotating barrel 11. As shown in fig. 1-4, in specific implementation, the rotary cylinder 11 can smoothly and horizontally rotate on the hydraulic cylinder 4 through the pushing bearing 13 and the large bearing 14, and meanwhile, through the cooperation of the static limiting block 16 and the dynamic limiting block 15, when the suspension arm 6 is positioned on one side of the center line of the cargo compartment 1, the rotation can be pushed by 90 degrees from left to right, and the rotation towards one side of the front passenger compartment is limited, so that the unnecessary trouble caused by collision of cargo and the like to the passenger compartment in the hoisting process is avoided.

The lifting arm is characterized by further comprising a supporting rod 17, a plurality of supporting holes 18 are formed in the lifting arm 6 at intervals, one end of the supporting rod 17 is hinged with the lower end of the rotary cylinder 11, and the other end of the supporting rod 17 is connected with the supporting holes 18. As shown in fig. 4, in specific implementation, the free end of the hinged support rod 17 is connected with different support holes 1818 through bolts, so as to control the elevation angle of the suspension arm 6, and the free end is matched with the lifting of the hydraulic cylinder 4, so as to hoist the goods with different heights.

Traction mechanism includes capstan winch 19, first pulley 20, second pulley 21 and lifting hook 22, davit 6 includes first cantilever 61 and second cantilever 62, first cantilever 61 one end is articulated with aircraft nose 5, be equipped with smooth chamber 63 on the first cantilever 61, second cantilever 62 slides and arranges in smooth chamber 63, first pulley 20 sets up and keeps away from aircraft nose 5 one end at first cantilever 61, second pulley 21 sets up and keeps away from aircraft nose 5 one end at second cantilever 62, the noose 64 of capstan winch 19 passes first pulley 20 and second pulley 21 in proper order and is connected with lifting hook 22. The first locking hole is arranged at one end, far away from the machine head 5, of the first cantilever 61 in a penetrating mode, the second locking holes are arranged on the second cantilever 62 at intervals, and after the second cantilever extends out of the sliding cavity 63 by a proper length, the corresponding first locking hole and the corresponding second locking hole are inserted through the bolt, so that the first cantilever 61 and the second cantilever 62 are locked, and relative sliding in the hoisting process is avoided.

In the specific implementation, as shown in fig. 1, the winch 19 uses a small vehicle-mounted winch, 12/24V vehicle power supply, and is mounted on the first cantilever 61, and the cable 64 of the winch 19 is engaged with the first pulley 20 and the second pulley 21, so that the hook 22 can be driven to lift the cargo.

Still including protecting seat 23, protecting seat 23 sets up at freight train locomotive 2 top, has seted up U-shaped groove 24 on protecting seat 23, and U-shaped groove 24 is located first cantilever 61's rotation route.

As shown in fig. 1, in the specific implementation, when the suspension arm 6 is located on one side of the vehicle head 2, the protection seat 23 and the U-shaped groove 24 thereof are disposed in the U-shaped groove 24, so as to prevent the suspension arm 6 from horizontally rotating, achieve the effect of fixing the suspension arm 6, and improve the driving safety during vehicle driving.

Grooves 510 are formed in the front plate 51 and the rear plate 52, rubber pads 25 are arranged in the grooves 510, and the grooves 510 are located on the rotation path of the boom 6.

As shown in fig. 2-4, in practical application, the grooves 510 on the front plate 51 and the rear plate 52 can increase the contact area with the boom 6, and the rubber pads 25 in the grooves 510 can not only play a role of buffering, but also protect the boom 6 and avoid abrasion between metals.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The utility model provides a small-size single cantilever vehicle-mounted loop wheel machine, sets up and is close to locomotive (2) one end in freight train packing box (1), its characterized in that: the hydraulic lifting device comprises a hydraulic cylinder (4), a machine head (5), a suspension arm (6) and a traction mechanism, wherein the hydraulic cylinder (4) is arranged in an inverted mode, a piston rod of the hydraulic cylinder (4) penetrates through a bottom plate (101) of a cargo box to be hinged with a vehicle girder (3), a fixing ring (7) is sleeved on a cylinder barrel of the hydraulic cylinder (4), the fixing ring (7) is hinged with the cargo box (1), the cylinder barrel of the hydraulic cylinder (4) is arranged in the fixing ring (7) in a sliding mode, the machine head (5) is horizontally and rotatably arranged at the upper end of the hydraulic cylinder (4), one end of the suspension arm (6) is hinged with the machine head (5), the suspension arm (6) can turn over back and forth along the cargo vehicle, and the traction mechanism is arranged on the suspension arm (6);

the machine head (5) comprises a front plate (51), a rear plate (52), a bottom plate (53) and two side plates (54), the bottom plate (53) is horizontally arranged, the two side plates (54) are vertically arranged at the left end and the right end of the bottom plate (53), the rear plate (52) and the front plate (51) are arranged at the two ends of the two side plates (54) in a sliding manner along the vertical direction, the front plate (51) is positioned at one end, close to the truck head (2), of the bottom plate (53), a rotating shaft (55) is rotatably arranged between the two side plates (54), and one end of the suspension arm (6) is sleeved on the rotating shaft (55);

the utility model discloses a spring assembly, including front bezel (51) and bottom plate (53), the interval is provided with a plurality of first springs (8) between front bezel (51) and bottom plate (53), the both ends of first spring (8) respectively with front bezel (51) and bottom plate (53) are connected, back plate (52) with the interval is provided with a plurality of second springs (9) between bottom plate (53), the both ends of second spring (9) respectively with back plate (52) and bottom plate (53) are connected.

2. The small single-cantilever crane with a truck as claimed in claim 1, wherein a resistance bar (10) is arranged at one end of the boom (6) close to the rotating shaft (55), a through hole (56) is formed in each of the front plate (51) and the rear plate (52), and the through hole (56) is located on a rotating path of the resistance bar (10).

3. A compact single boom truck crane according to claim 2, characterized in that the thickness and width of the back plate (52) are the same as the thickness and width of the front plate (51), the length of the back plate (52) being longer than the length of the front plate (51).

4. The small single-cantilever truck-mounted crane according to claim 3, wherein sliding grooves (57) are formed in two ends of each of the two side plates (54), first sliding blocks (58) are arranged at two ends of the front plate (51), second sliding blocks (59) are arranged at two ends of the rear plate (52), and the first sliding blocks (58) and the second sliding blocks (59) are respectively slidably arranged in the sliding grooves (57) at two ends of the side plates (54).

5. The small single-cantilever crane with a truck as claimed in claim 1, further comprising a rotating cylinder (11), wherein the upper end of the rotating cylinder (11) is sealed, the rotating cylinder (11) is sleeved on the upper end of the hydraulic cylinder (4), the bottom plate (53) is sleeved on the upper end of the rotating cylinder (11), a limiting shaft (12) is vertically arranged at the top of the hydraulic cylinder (4), the limiting shaft (12) penetrates through the rotating cylinder (11), a pushing bearing (13) is sleeved on the limiting shaft (12), and two ends of the pushing bearing (13) are respectively abutted against the rotating cylinder (11) and the hydraulic cylinder (4);

a large bearing (14) is sleeved on a cylinder barrel of the hydraulic cylinder (4), and the outer end of the large bearing (14) is abutted to the inner wall of the lower end of the rotating cylinder (11).

6. The small single-cantilever truck-mounted crane according to claim 5, wherein a movable limiting block (15) is arranged at the lower end of the rotary cylinder (11), two static limiting blocks (16) are arranged on the opposite sides of the fixed ring (7), and the static limiting blocks (16) are positioned on the rotation path of the movable limiting block (15).

7. The small single-cantilever crane with a truck as claimed in claim 5, further comprising a support rod (17), wherein a plurality of support holes (18) are arranged at intervals on the boom (6), one end of the support rod (17) is hinged with the lower end of the rotary drum (11), and the other end of the support rod (17) is connected with the support holes (18).

8. A small single boom truck mounted crane according to claim 1, characterized in that the traction mechanism comprises a winch (19), a first pulley (20), a second pulley (21) and a hook (22), the boom (6) comprises a first boom (61) and a second boom (62), one end of the first cantilever (61) is hinged with the machine head (5), a sliding cavity (63) is arranged on the first cantilever (61), the second cantilever (62) is arranged in the sliding cavity (63) in a sliding way, the first pulley (20) is arranged at one end of the first cantilever (61) far away from the machine head (5), the second pulley (21) is arranged at one end of the second cantilever (62) far away from the machine head (5), the cable (64) of the winch (19) passes through the first pulley (20) and the second pulley (21) in sequence to be connected with the hook (22).

9. The small single-cantilever truck-mounted crane according to claim 8, further comprising a protective seat (23), wherein the protective seat (23) is arranged on the top of the truck head (2), a U-shaped groove (24) is formed in the protective seat (23), and the U-shaped groove (24) is located on a rotation path of the first cantilever (61).

10. A small single-boom truck-mounted crane according to claim 1, characterized in that the front plate (51) and the rear plate (52) are each provided with a groove (510), a rubber pad (25) is arranged in each groove (510), and the grooves (510) are located in the rotation path of the boom (6).

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