CN112723144B

CN112723144B - Crane with anti-falling function

Info

Publication number: CN112723144B
Application number: CN202110128677.3A
Authority: CN
Inventors: 施振菊
Original assignee: Jiangsu Jianyou Construction Machinery Co ltd
Current assignee: Jiangsu Jianyou Construction Machinery Co ltd
Priority date: 2021-01-29
Filing date: 2021-01-29
Publication date: 2024-04-26
Anticipated expiration: 2041-01-29
Also published as: CN112723144A

Abstract

The invention relates to the field of cranes, in particular to a crane with an anti-falling function, which comprises a shell and a hook, wherein two sides of the bottom end of the shell are fixedly connected with fixing plates, a supporting plate is arranged between the two fixing plates, buffer mechanisms are arranged between two ends of the supporting plate and corresponding fixing plates, the upper end of the hook is fixedly connected with a mounting column, the upper end of the mounting column is movably sleeved with the supporting plate, a mounting mechanism is arranged between the mounting column and the supporting plate, an auxiliary groove is arranged on the inner surface of the hook, a supporting mechanism is arranged in the auxiliary groove, a guide mechanism is arranged at the bottom end of the supporting mechanism, a limiting mechanism is arranged outside the guide mechanism through a connecting block, and the upper end of the limiting mechanism corresponds to the supporting mechanism. Through carrying out multiple spacing to the lifting rope, prevent that the lifting rope from appearing sliding or unhooking the phenomenon in the couple, guarantee the stability of lifting rope and heavy object when removing to guarantee safety, simultaneously, also guaranteed the life of couple.

Description

Crane with anti-falling function

Technical Field

The invention relates to the field of cranes, in particular to a crane with an anti-falling function.

Background

A crane refers to a multi-action lifting machine that vertically lifts and horizontally conveys weights within a certain range. The crane is characterized in that the crane is operated intermittently, namely, corresponding mechanisms of taking, transporting, unloading and the like in one working cycle are operated alternately, and the crane is developed and used more and more widely in the market. Because landing leg hanging weight and hanging weight running are not needed, accidents often occur, and the running speed is higher than that of a crawler crane (crawler crane); the operation is stable, the lifting capacity is high, the crane can walk in a specific range, but the road is smooth and firm, the tire pressure meets the requirement, and the crane cannot be lifted off the ground by more than 50CM; and forbidding long-distance walking with load. In order to ensure the operation safety, the hoisting operation without landing leg is basically forbidden in China at present. The steel wire rope varieties matched with the crane comprise phosphatized coating steel wire ropes, galvanized steel wire ropes and polished steel wire ropes.

The existing hanging parts of the hanging hooks of part cranes are all in an open state, when the hanging rope with the heavy objects is hung on the hanging hooks, and when the hanging hooks drive the heavy objects to move in the air, the hanging rope can slide on the hanging hooks due to the fact that the hanging rope does not have a good limiting device, so that the stability of the heavy objects in the air can be affected, the hanging rope is more likely to fall off from the hanging hooks, accidents occur, meanwhile, the hanging hooks have no good buffer device when the heavy objects are loaded to move, and the service life of the hanging hooks can be affected to a certain extent.

Disclosure of Invention

Aiming at the problems that in the prior art, the hanging parts of part of the hanging hooks of the crane are in an open state, when the hanging rope with the heavy object is hung on the hanging hooks, and the hanging hooks drive the heavy object to move in the air, as no good limiting device exists, the hanging rope can slide on the hanging hooks, so that the stability of the heavy object in the air can be influenced, the hanging rope is more likely to fall off from the hanging hooks to cause accidents, and meanwhile, the hanging hooks have no good buffering device when the heavy object is loaded to move, so that the service life of the hanging hooks can be influenced to a certain extent.

The technical scheme adopted for solving the technical problems is as follows: the utility model provides a hoist with anticreep thing function, includes casing and couple, the equal fixedly connected with fixed plate in casing bottom both sides, two be equipped with the backup pad between the fixed plate, all be equipped with buffer gear between backup pad both ends and the corresponding fixed plate, couple upper end fixedly connected with erection column, erection column upper end and backup pad activity cup joint, be equipped with installation mechanism between erection column and the backup pad, the couple internal surface is equipped with the auxiliary tank, be equipped with supporting mechanism in the auxiliary tank, the supporting mechanism bottom is equipped with guiding mechanism, the guiding mechanism outside is equipped with stop gear through the connecting block, stop gear upper end corresponds with supporting mechanism; the two buffer mechanisms comprise grooves, mounting blocks, pistons, cavities and second springs, the two opposite sides of the fixing plate are respectively provided with a groove, two ends of the supporting plate are respectively inserted into the two grooves, the two ends of the supporting plate are respectively fixedly connected with the mounting blocks, the two ends of the supporting plate are respectively fixedly connected with the pistons, the two sides of the mounting blocks are respectively fixedly connected with the pistons, the two pistons and the corresponding groove side walls form the cavities, the two ends of the supporting plate are respectively sleeved with the second springs, and the two second springs are respectively sleeved on the peripheries of the two ends of the supporting plate.

Specifically, the installation mechanism comprises a sleeve block, a first through hole, external threads, a nut and a first spring, the sleeve block is arranged above the supporting plate, the upper end of the installation column is movably sleeved with the sleeve block through the first through hole, the outer side of the upper end of the installation column is connected with the nut through the external threads, the nut is in contact with the upper end of the sleeve block, the first spring is fixedly connected between the sleeve block and the supporting plate, and the first spring is sleeved on the periphery of the installation column.

Specifically, supporting mechanism includes two side grooves, two montants, two mounting holes, supporting shoe and two third springs, all be equipped with the side groove on the auxiliary tank both sides wall, two all perpendicular is fixed with the montant in the side groove, two all be equipped with the supporting shoe between the side groove, the supporting shoe both ends cup joint with two montant activities through two mounting holes, equal fixedly connected with third spring between supporting shoe both ends and the corresponding side groove diapire, two the third spring overlaps respectively and establishes at two montant outsides.

Specifically, guiding mechanism includes guide bar, guide way, bottom block, two spouts, reference column, constant head tank and fourth spring, the guide bar is fixed perpendicularly in supporting shoe bottom central point put, the connecting block is fixed to be cup jointed in the guide bar outside, the auxiliary tank diapire is equipped with the guide way with the guide bar looks adaptation, the guide bar lower extreme is inserted and is established in the guide way, guide bar bottom fixedly connected with bottom block, all be equipped with the spout with bottom block looks adaptation on the guide way both sides wall, bottom block both ends respectively with two spouts sliding connection, guide bar tank bottom wall central point put vertical fixation has the reference column, the guide bar bottom is equipped with the constant head tank with the reference column looks adaptation, the reference column upper end is inserted and is established in the constant head tank, fixedly connected with fourth spring between bottom block and the guide way diapire, the fourth spring cover is established at the reference column periphery.

Specifically, stop gear includes first side piece, second side piece, fixed column, first opening, riser, second opening, roof, socket, extrusion piece and a plurality of tooth piece, first side piece of connecting block both sides fixedly connected with and second side piece respectively, fixed column and riser are located the guide bar both sides respectively, fixed column fixed connection is on the auxiliary tank diapire, fixed column upper end and first side piece activity cup joint, first opening and second opening are all offered on the supporting shoe, the fixed column top is inserted and is established in first opening, the riser is fixed perpendicularly and is fixed on the second side piece, the riser cup joints with the supporting shoe activity through the second opening, riser top fixedly connected with roof, be equipped with the socket corresponding with the fixed column on the roof, roof bottom fixedly connected with extrusion piece, extrusion piece bottom fixedly connected with a plurality of tooth pieces.

Specifically, inclined planes are arranged on two sides of the upper end of the supporting block, a clamping groove is formed in the center of the upper end of the supporting block, and the clamping groove corresponds to the extrusion block.

Specifically, be equipped with two slots in the backup pad, two slot are located the erection column both sides respectively, two all insert in the slot and be equipped with the inserted bar, two the inserted bar is fixed perpendicularly respectively in cover piece both sides bottom, two the fixed block has all been fixedly cup jointed in the inserted bar bottom outside, two the equal fixedly connected with in the fixed block outside a plurality of stoppers, two all be equipped with a plurality of spacing grooves with stopper looks adaptation on the slot lateral wall, a plurality of stopper respectively with a plurality of spacing groove sliding connection.

The invention has the beneficial effects that:

(1) According to the crane with the anti-falling function, when the crane drives the lifting rope and the heavy object to rise through the hook, the hook moves upwards, the supporting block does not move upwards, so that the supporting block can extrude the two third springs to enable the two third springs to be in a compressed state, meanwhile, the guide rod can be inserted into the guide groove to extrude the fourth spring, stability of the guide rod in moving is guaranteed through the positioning groove and the positioning column, the guide rod enables the top plate to move downwards through the connecting block and the vertical plate when being inserted into the guide groove, the lifting rope is limited through the extrusion block and the tooth blocks when the top plate moves downwards, sliding or unhooking of the lifting rope is prevented, the upper end of the fixing column is combined with the socket when the top plate moves downwards, the lifting rope is further limited, stability of the lifting rope and the heavy object in the air is guaranteed, and therefore safety is guaranteed.

(2) According to the crane with the anti-falling function, when the hook drives the heavy object to move in the air, the hook drives the mounting column to move laterally, the second springs are extruded or stretched through the supporting plate, a certain buffer effect can be achieved by utilizing acting forces of the two second springs, and negative pressure can be generated in the cavity when the piston is pulled by the supporting plate, so that the buffer effect can be further enhanced, and the service life of the hook is guaranteed.

(3) According to the crane with the anti-falling function, the nut is rotated to separate the nut from the mounting column, so that the mounting column and the hook can be easily detached, the hook can be conveniently replaced and maintained, the disassembly time is saved, and time and labor are saved.

Drawings

The invention will be further described with reference to the drawings and examples.

FIG. 1 is a schematic diagram of a crane with anti-drop function according to the present invention;

fig. 2 is a schematic diagram of a partial structure of a crane with an anti-falling function according to the present invention;

fig. 3 is an enlarged schematic diagram of a structure of a crane with an anti-falling function according to the present invention;

fig. 4 is an enlarged schematic diagram of a structure at position B of a crane with an anti-falling function according to the present invention;

fig. 5 is a schematic diagram of a top plate structure of a crane with an anti-falling function according to the present invention;

FIG. 6 is a schematic cross-sectional view of a connection between a plunger and a socket of a crane with anti-drop function according to the present invention;

Fig. 7 is a schematic structural diagram of a supporting block of a crane with an anti-falling function.

In the figure: 1. a housing; 2. a fixing plate; 3. a mounting column; 4. a hook; 5. a mounting mechanism; 51. an external thread; 52. a nut; 53. sleeving blocks; 54. a first through hole; 55. a first spring; 6. a buffer mechanism; 61. a cavity; 62. a groove; 63. a piston; 64. a mounting block; 65. a second spring; 7. a limiting mechanism; 71. a top plate; 72. a socket; 73. a riser; 74. extruding a block; 75. tooth blocks; 76. a second port; 77. fixing the column; 78. a first side block; 79. a first port; 710. a second side block; 8. a support mechanism; 81. a support block; 82. a side groove; 83. a third spring; 84. a mounting hole; 85. a vertical rod; 9. a guide mechanism; 91. a guide rod; 92. a positioning groove; 93. positioning columns; 94. a bottom block; 95. a chute; 96. a guide groove; 97. a fourth spring; 10. a support plate; 11. an auxiliary groove; 12. a rod; 13. a clamping groove; 14. an inclined plane; 15. a fixed block; 16. a slot; 17. a limit groove; 18. a limiting block; 19. and (5) connecting a block.

Detailed Description

The invention is further described in connection with the following detailed description in order to make the technical means, the creation characteristics, the achievement of the purpose and the effect of the invention easy to understand.

As shown in fig. 1-7, the crane with the anti-falling function comprises a shell 1 and a hook 4, wherein two sides of the bottom end of the shell 1 are fixedly connected with fixing plates 2, a supporting plate 10 is arranged between the two fixing plates 2, buffer mechanisms 6 are arranged between two ends of the supporting plate 10 and the corresponding fixing plates 2, a mounting column 3 is fixedly connected to the upper end of the hook 4, the upper end of the mounting column 3 is movably sleeved with the supporting plate 10, a mounting mechanism 5 is arranged between the mounting column and the supporting plate 10, an auxiliary groove 11 is arranged on the inner surface of the hook 4, a supporting mechanism 8 is arranged in the auxiliary groove 11, a guiding mechanism 9 is arranged at the bottom end of the supporting mechanism 8, a limiting mechanism 7 is arranged on the outer side of the guiding mechanism 9 through a connecting block 19, the upper end of the limiting mechanism 7 corresponds to the supporting mechanism 8, and through multiple limiting of a lifting rope, the sliding or unhooking phenomenon of the lifting rope in the hook 4 is prevented, the stability of the lifting rope and a heavy object during movement is ensured, so that safety is ensured, and meanwhile, the service life of the hook 4 is also ensured.

Specifically, two buffer gear 6 all include recess 62, installation piece 64, piston 63, cavity 61 and second spring 65, two fixed plate 2 opposite sides all are equipped with recess 62, the backup pad 10 both ends are inserted respectively and are established in two recesses 62, the equal fixedly connected with installation piece 64 in backup pad 10 both ends, two equal fixedly connected with pistons 63 in one side of installation piece 64, all form cavity 61 between two pistons 63 and the corresponding recess 62 lateral wall, two equal fixedly connected with second spring 65 between two installation piece 64 and the corresponding recess 62 inner wall, two second springs 65 overlap respectively establish at backup pad 10 both ends periphery, couple 4 drives the heavy object when moving in the sky, couple 4 drives when erection column 3 lateral movement, can extrude or tensile second spring 65 through backup pad 10, utilize the effort of two second springs 65 can play certain cushioning effect, backup pad 10 when pulling piston 63, can make in the cavity 61 produce the negative pressure, thereby can further strengthen the cushioning effect, guarantee couple 4's life.

Specifically, the installation mechanism 5 includes cover piece 53, first through-hole 54, external screw thread 51, nut 52 and first spring 55, backup pad 10 top is equipped with the cover piece 53, the erection column 3 upper end is cup jointed with cover piece 53 activity through first through-hole 54, there is nut 52 at the erection column 3 upper end outside through external screw thread 51 threaded connection, nut 52 and cover piece 53 upper end contact, fixedly connected with first spring 55 between cover piece 53 and the backup pad 10, first spring 55 cover is established at erection column 3 periphery, rotate nut 52, make nut 52 and erection column 3 separation, can very light erection column 3 and couple 4 dismantle, thereby be convenient for change and maintenance to couple 4, save the dismouting time, labour saving and time saving.

Specifically, supporting mechanism 8 includes two side slots 82, two montants 85, two mounting holes 84, supporting shoe 81 and two third springs 83, all be equipped with side slot 82 on the lateral wall of auxiliary tank 11, all be fixed with montant 85 perpendicularly in two side slots 82, all be equipped with supporting shoe 81 between two side slots 82, supporting shoe 81 both ends are cup jointed with two montant 85 activity through two mounting holes 84, equal fixedly connected with third springs 83 between supporting shoe 81 both ends and the corresponding side slot 82 diapire, two third springs 83 overlap respectively and establish at two montant 85 periphery, when the hoist passes through couple 4 and drives lifting rope and heavy object and rise, couple 4 shifts up, and supporting shoe 81 can not shift up, consequently supporting shoe 81 can extrude two third springs 83, make two third springs 83 be in compression state.

Specifically, guiding mechanism 9 includes guide bar 91, guide slot 96, the bottom block 94, two spouts 95, reference column 93, constant head tank 92 and fourth spring 97, guide bar 91 vertical fixation is in supporting shoe 81 bottom central point put, connecting block 19 is fixed cup joint in the guide bar 91 outside, auxiliary tank 11 diapire is equipped with the guide slot 96 with guide bar 91 looks adaptation, guide bar 91 lower extreme inserts and establishes in guide slot 96, guide bar 91 bottom fixedly connected with bottom block 94, all be equipped with on the lateral wall of guide slot 96 with spout 95 looks adaptation of bottom block 94, bottom block 94 both ends respectively with two spouts 95 sliding connection, guide slot 96 diapire central point put vertical fixation have reference column 93, the guide bar 91 bottom is equipped with the constant head tank 92 with the constant head tank 93 looks adaptation, the constant head tank 93 upper end inserts and establishes in the constant head tank 92, fixedly connected with fourth spring 97 between bottom block 94 and the guide slot 96 diapire, fourth spring 97 overlaps and establishes at the periphery of constant head tank 93, guide bar 91 also can insert in guide slot 96, extrude fourth spring 97, stability when guaranteeing through constant head tank 92 and constant head tank 93.

Specifically, stop gear 7 includes first side piece 78, second side piece 710, fixed column 77, first through-hole 79, riser 73, second through-hole 76, roof 71, socket 72, extrusion piece 74 and a plurality of tooth piece 75, connecting block 19 both sides are fixedly connected with first side piece 78 and second side piece 710 respectively, fixed column 77 and riser 73 are located guide bar 91 both sides respectively, fixed column 77 fixed connection is on the sub-tank 11 diapire, fixed column 77 upper end and first side piece 78 activity cup joint, first through-hole 79 and second through-hole 76 all offer on supporting shoe 81, the fixed column 77 top is inserted and is established in first through-hole 79, riser 73 fixed vertical fixation is on second side piece 710, riser 73 passes through second through-hole 76 and the activity cup joints of supporting shoe 81, riser 73 top fixedly connected with roof 71, be equipped with the socket 72 corresponding with fixed column 77 on the roof 71, roof 71 bottom fixedly connected with extrusion piece 74 bottom fixedly connected with a plurality of tooth piece 75, guide bar 91 makes through 19 and riser 73 and move down through the movement of jack 71 when inserting guide bar 91 in guide slot 96 and during the time of messenger's position rope, prevent that lifting rope and rope from moving down at the top of hanging down in the roof 71, and the rope position is guaranteed to take place, the lifting rope position is fixed to the rope position and the rope position is fixed to the position is down, and is guaranteed to the lifting rope position is down to the top to the rope position to be combined with the top to the roof 71.

Specifically, inclined planes 14 are respectively arranged on two sides of the upper end of the supporting block 81, a clamping groove 13 is arranged at the central position of the upper end of the supporting block 81, the clamping groove 13 corresponds to the extrusion block 74, the lifting rope is placed in the clamping groove 13, the lifting rope is positioned through the clamping groove 13, the clamping groove 13 is matched with the extrusion block 74 again to limit the lifting rope, and the sliding of the lifting rope is prevented.

Specifically, be equipped with two slots 16 on the backup pad 10, two slot 16 are located the erection column 3 both sides respectively, all insert and be equipped with inserted bar 12 in two slots 16, two inserted bar 12 are fixed perpendicularly respectively in cover piece 53 both sides bottom, fixed block 15 has all been fixed to the equal fixed sleeve in two inserted bar 12 bottom outsides, a plurality of stopper 18 of equal fixedly connected with in two fixed block 15 outsides, all be equipped with a plurality of spacing grooves 17 with stopper 18 looks adaptation on two slot 16 lateral walls, a plurality of stopper 18 respectively with a plurality of spacing groove 17 sliding connection, stability when guaranteeing the removal of cover piece 53, thereby make the stable extrusion to first spring 55 of cover piece 53, and then guarantee the cushioning effect.

When in use, the lifting rope is placed in the clamping groove 13, the clamping groove 13 is utilized to limit the lifting rope, when the crane drives the lifting rope and the heavy object to ascend through the hook 4, the hook 4 moves upwards, the supporting block is not moved upwards by the acting force 81 of the heavy object, therefore, the supporting block 81 can extrude the two third springs 83, the two third springs 83 are in a compressed state, meanwhile, the guide rod 91 can be inserted into the guide groove 96 to extrude the fourth spring 97, the stability of the guide rod 91 in moving is ensured through the positioning groove 92 and the positioning column 93, the top plate 71 moves downwards through the connecting block 19 and the vertical plate 73 when the guide rod 91 is inserted into the guide groove 96, the lifting rope is limited through the extruding block 74 and the plurality of tooth blocks 75 when the top plate 71 moves downwards, the lifting rope is prevented from sliding or unhooking when the top plate 71 moves downwards, the fixed column 77 upper end can combine together with socket 72, further carry out spacingly to the lifting rope, guarantee lifting rope and heavy object stability in the sky, thereby guarantee safety, couple 4 drives the heavy object when moving in the sky, couple 4 drives when erection column 3 lateral movement, can extrude or stretch second spring 65 through backup pad 10, can play certain cushioning effect by the effort of two second springs 65, backup pad 10 can make the cavity 61 produce the negative pressure when pulling piston 63, thereby can further strengthen the cushioning effect, guarantee couple 4's life, when maintaining and changing couple 4 in the later stage, rotate nut 52, make nut 52 and erection column 3 separation, can very light erection column 3 and couple 4 dismantle, thereby be convenient for change and maintenance to couple 4, save the dismouting time, labour saving and time saving.

The invention has the beneficial effects that:

The foregoing has shown and described the basic principles, principal features and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the foregoing examples, and that the foregoing description and description are merely illustrative of the principles of this invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The utility model provides a hoist with anticreep thing function, includes casing (1) and couple (4), its characterized in that, casing (1) bottom both sides all fixedly connected with fixed plate (2), two be equipped with backup pad (10) between fixed plate (2), all be equipped with buffer gear (6) between backup pad (10) both ends and the corresponding fixed plate (2), couple (4) upper end fixedly connected with erection column (3), erection column (3) upper end and backup pad (10) activity cup joint, be equipped with installation mechanism (5) between erection column (3) and backup pad (10), couple (4) internal surface is equipped with auxiliary tank (11), be equipped with supporting mechanism (8) in auxiliary tank (11), supporting mechanism (8) bottom is equipped with guiding mechanism (9), guiding mechanism (9) outside is equipped with stop gear (7) through connecting block (19), stop gear (7) upper end and supporting mechanism (8) are corresponding; the two buffer mechanisms (6) comprise grooves (62), mounting blocks (64), pistons (63), cavities (61) and second springs (65), the grooves (62) are formed in opposite sides of the two fixing plates (2), two ends of the supporting plate (10) are respectively inserted into the two grooves (62), the mounting blocks (64) are fixedly connected to two ends of the supporting plate (10), the pistons (63) are fixedly connected to one sides of the two mounting blocks (64), the cavities (61) are formed between the two pistons (63) and the side walls of the corresponding grooves (62), the second springs (65) are fixedly connected between the two mounting blocks (64) and the inner walls of the corresponding grooves (62), and the two second springs (65) are respectively sleeved on the peripheries of two ends of the supporting plate (10); the mounting mechanism (5) comprises a sleeve block (53), a first through hole (54), an external thread (51), a nut (52) and a first spring (55), wherein the sleeve block (53) is arranged above the supporting plate (10), the upper end of the mounting column (3) is movably sleeved with the sleeve block (53) through the first through hole (54), the nut (52) is connected with the outer side of the upper end of the mounting column (3) through the external thread (51) in a threaded manner, the nut (52) is in contact with the upper end of the sleeve block (53), the first spring (55) is fixedly connected between the sleeve block (53) and the supporting plate (10), and the first spring (55) is sleeved on the periphery of the mounting column (3); the supporting mechanism (8) comprises two side grooves (82), two vertical rods (85), two mounting holes (84), supporting blocks (81) and two third springs (83), wherein the side grooves (82) are formed in two side walls of the auxiliary groove (11), the vertical rods (85) are vertically fixed in the side grooves (82), the supporting blocks (81) are arranged between the side grooves (82), two ends of each supporting block (81) are movably sleeved with the two vertical rods (85) through the two mounting holes (84), the third springs (83) are fixedly connected between two ends of each supporting block (81) and the bottom wall of the corresponding side groove (82), and the two third springs (83) are sleeved on the peripheries of the two vertical rods (85) respectively; the guide mechanism (9) comprises a guide rod (91), a guide groove (96), a bottom block (94), two sliding grooves (95), a positioning column (93), a positioning groove (92) and a fourth spring (97), wherein the guide rod (91) is vertically fixed at the center position of the bottom end of the support block (81), the connecting block (19) is fixedly sleeved outside the guide rod (91), the bottom wall of the auxiliary groove (11) is provided with the guide groove (96) matched with the guide rod (91), the lower end of the guide rod (91) is inserted into the guide groove (96), the bottom block (94) is fixedly connected to the bottom end of the guide rod (91), the sliding grooves (95) matched with the bottom block (94) are formed in the two side walls of the guide groove (96), the two ends of the bottom block (94) are respectively and slidably connected with the two sliding grooves (95), the positioning column (93) is fixedly arranged at the center position of the bottom wall of the guide groove (96), the bottom end of the guide rod (91) is provided with the positioning groove (92) matched with the positioning column (93), the positioning groove (92) and the positioning block (92) is fixedly arranged between the bottom wall of the fourth spring (93), and the fourth spring (97) is fixedly arranged between the bottom block and the bottom block (93). The limiting mechanism (7) comprises a first side block (78), a second side block (710), a fixed column (77), a first through hole (79), a vertical plate (73), a second through hole (76), a top plate (71), a socket (72), an extrusion block (74) and a plurality of tooth blocks (75), wherein the first side block (78) and the second side block (710) are fixedly connected to two sides of the connecting block (19) respectively, the fixed column (77) and the vertical plate (73) are positioned on two sides of the guide rod (91) respectively, the fixed column (77) is fixedly connected to the bottom wall of the auxiliary groove (11), the upper end of the fixed column (77) is movably sleeved with the first side block (78), the first through hole (79) and the second through hole (76) are formed in the supporting block (81), the top end of the fixed column (77) is inserted in the first through hole (79), the vertical plate (73) is fixedly and vertically fixed on the second side block (710), the vertical plate (73) is fixedly connected with the supporting block (91) through the second through hole (76) and the corresponding top plate (71), the top plate (71) is fixedly connected to the top plate (71), the bottom end of the extrusion block (74) is fixedly connected with a plurality of tooth blocks (75); inclined planes (14) are arranged on two sides of the upper end of the supporting block (81), a clamping groove (13) is formed in the center of the upper end of the supporting block (81), and the clamping groove (13) corresponds to the extrusion block (74); two slots (16) are formed in the supporting plate (10), the two slots (16) are respectively located on two sides of the mounting column (3), the two inserting rods (12) are respectively inserted in the slots (16), the two inserting rods (12) are respectively and vertically fixed at two bottom ends of two sides of the sleeve block (53), the two fixing blocks (15) are fixedly sleeved on the outer sides of the bottom ends of the inserting rods (12), the two fixing blocks (15) are fixedly connected with a plurality of limiting blocks (18) on the outer sides of the fixing blocks (15), a plurality of limiting grooves (17) matched with the limiting blocks (18) are formed in the side walls of the slots (16), and the limiting blocks (18) are respectively and slidably connected with the limiting grooves (17).