CN210388054U

CN210388054U - Welding device for stud on inner wall of open caisson

Info

Publication number: CN210388054U
Application number: CN201920822786.3U
Authority: CN
Inventors: 李妍琳; 邱娟; 李东; 洪峰; 苏武平; 潘邵斌; 张晨
Original assignee: Wuhan Wuchang Municipal Construction Group Co ltd
Current assignee: Wuhan Wuchang Municipal Construction Group Co ltd
Priority date: 2019-06-03
Filing date: 2019-06-03
Publication date: 2020-04-24
Anticipated expiration: 2029-06-03

Abstract

The utility model discloses a welding device of open caisson inner wall double-screw bolt, relate to municipal open caisson construction appurtenance's technical field, it includes the support, support up end swing joint has a supporting beam, a supporting beam keeps away from the vertical rotation of one end of support and is connected with the screw rod, it is used for driving screw rod pivoted drive arrangement to be provided with on the supporting beam, threaded connection has the slip table on the screw rod, the one end rigid coupling that the slip table is close to the support has welder, a supporting beam is close to the tip rigid coupling of screw rod has the gag lever post that is on a parallel with the screw rod, the gag lever post runs through the one end that welder was kept away from to. The utility model discloses a slip table that the lift set up drives welder and stretches into to weld the welding of outstanding double-screw bolt in old, need not constructor and operates in going down the open caisson, has reduced the potential safety hazard, has also reduced the human cost, has improved the efficiency of construction.

Description

Welding device for stud on inner wall of open caisson

Technical Field

The utility model belongs to the technical field of municipal administration open caisson construction appurtenance's technique and specifically relates to a weld melting device of open caisson inner wall double-screw bolt is related to.

Background

The open caisson is a well cylindrical structure, and is a foundation for bridge abutment or other structures by digging soil in the well, overcoming the frictional resistance of the well wall by means of the self gravity, sinking to a designed elevation, sealing the bottom by concrete and filling the well hole. The method is generally used for constructing the enclosure device of foundation pits of large-scale piers, sewage pump stations, large-scale equipment foundations, civil air defense shelters, shield assembly wells, underground driveways and station hydraulic foundations. In municipal construction, the caisson is usually used as an observation well of a drainage pipeline or a pipeline laying pipeline, the caisson main body is made of reinforced concrete, a template is generally arranged on the ground in an enclosing mode, a reinforcement cage is woven in the template after the template is fixed, then concrete is poured in the template, the caisson main body is settled to a set elevation by means of the gravity of the caisson main body after being condensed, and the caisson cannot be normally settled due to the blocking of sand and stones.

In order to solve the problems, the Chinese patent with the patent publication number of CN206337572U provides an underground open caisson for municipal engineering, which comprises a well wall, wherein an accommodating cavity for accommodating a well body is arranged in the middle of the well wall; a sliding structure which moves up and down is arranged between the inner wall of the well wall and the outer wall of the well body, and the sliding structure comprises more than one convex part which is arranged outside the well body and is vertical to the well body; the inner side surface of the well wall opposite to the convex part is provided with a concave part corresponding to the convex part, and a rolling piece is embedded into the concave part. The utility model discloses a well wall that adopts steel to make and the well body interact that concrete reinforcement material made form for whole open caisson can guarantee at first the well body fast target in place at the automatic decline in-process, and whether the optional wall of a well of pulling out, solve the open caisson and appear leading to the condition of sinking offset or can not normally sink through the grit contact when the dead weight descends.

The above prior art solutions have the following drawbacks: for guaranteeing the overall stability of the open caisson template when the open caisson template is fixed, a plurality of groups of waterproof counter-pulling screws are required to be arranged on the template to carry out counter-pulling fixation on the template on the opposite side, so that a plurality of studs protruding on the inner side wall of the template are required to be arranged in the template to be used for being in threaded connection with the counter-pulling screws, and after the open caisson is poured, the studs protrude inside the open caisson and need to be cut off. In the existing construction, a constructor is usually required to descend into the open caisson to weld the contact part of the stud and the inner wall of the open caisson by a welding gun, a large amount of toxic gas is generated in the welding process, the health of the constructor is seriously influenced, and the danger is high.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a simple operation's open caisson inner wall double-screw bolt weld melting device.

The utility model aims at realizing through the following technical scheme:

the utility model provides a welding device of open caisson inner wall double-screw bolt, includes the support, support up end swing joint has a supporting beam, a supporting beam is kept away from the vertical rotation of one end of support is connected with the screw rod, be provided with on the supporting beam and be used for the drive screw rod pivoted drive arrangement, threaded connection has the slip table on the screw rod, the slip table is close to the one end rigid coupling of support has welder, a supporting beam is close to the tip rigid coupling of screw rod have be on a parallel with the gag lever post of screw rod, the gag lever post runs through the slip table is kept away from welder's one end, the terminal surface still is provided with the recovery unit who is used.

By adopting the technical scheme, the bracket is fixed on the ground at the periphery of the open caisson, the screw rod is driven to rotate by the driving device, the screw rod drives the sliding table matched with the screw thread to move when rotating, and meanwhile, the limiting rod has a limiting effect on the sliding table, so that the sliding table moves up and down along the length direction of the screw rod; the position of the support beam on the support is adjusted, so that the welding gun aligns at the joint of the stud and the inner wall of the open caisson, the welding gun is started, the screw rod falls off from the inner wall of the open caisson and is transferred into the recovery device below the screw rod after the welding gun welds the end part of the stud, the welding device effectively welds and collects the stud, operation of constructors in the open caisson is not needed, physical and mental health of the constructors is guaranteed as far as possible, labor cost is reduced, and construction efficiency is improved.

Further setting the following steps: the support upper end surface is horizontally and rotatably connected with a sliding rail matched with the support beam in a sliding manner, the cross section of the sliding rail is C-shaped, and a positioning bolt with one end in contact with the upper end surface of the support beam penetrates through the upper end surface of the sliding rail in a threaded manner.

By adopting the technical scheme, after the support is fixed on the ground, the support beam can stretch out and draw back in the slide rail, so that the distance between the welding gun and the inner wall of the open caisson can be adjusted, and the welding operation is more convenient; the positioning bolt can fix the position of the support beam in the slide rail, so that the influence of the support beam sliding on the welding operation when the welding gun works is avoided as much as possible.

Further setting the following steps: the lower end face of the sliding rail is fixedly connected with a rotating shaft which is rotatably connected with the upper end face of the support, the peripheral wall of the rotating shaft is provided with an annular groove perpendicular to the axis of the rotating shaft, the upper end face of the support is fixedly provided with a plurality of positioning pieces, and fixing bolts pointing to the annular groove penetrate through the threads of the positioning pieces.

By adopting the technical scheme, the sliding rail rotates on the support through the rotating shaft, so that the welding gun is driven to swing in the open caisson to a certain extent, and when the support is fixed at one position through the sliding fit of the support beam in the sliding rail, the welding gun can perform welding operation on studs at a plurality of positions in the open caisson, so that the low working efficiency caused by frequently moving the position of the support is avoided; when the welding gun is prepared to perform welding operation, the end parts of the fixing bolts are abutted to the bottom wall of the annular groove by rotating the fixing bolts, so that the rotating shaft is fixed, and the welding tongs can be effectively prevented from driving the supporting beam to move by the sliding rail during operation to influence the welding efficiency.

Further setting the following steps: the slip table is close to the lower terminal surface elasticity of welder one end is provided with the frame of pressing that is used for pressing the double-screw bolt, press the frame including elastic connection just be the mobile jib that the level set up on the slip table, the mobile jib is kept away from the one end rigid coupling of slip table has the decurrent U type depression bar of opening.

By adopting the technical scheme, when the sliding table drives the welding gun to move downwards, the U-shaped pressure rod is firstly contacted with the stud, when the welding gun welds the joint of the stud and the inner wall of the open caisson, the screw rod can be slowly driven to rotate so as to drive the sliding table to slowly descend, the U-shaped pressure rod applies pressure downwards to one end, away from the inner wall of the open caisson, of the stud by virtue of the main rod elastically arranged on the sliding table, so that the welding gun can effectively aim at the unwelded part of the cross section of the stud in the welding process, the fusing speed of the stud is accelerated, and meanwhile, the gas consumption of the.

Further setting the following steps: the end part of the sliding table, which is close to the welding gun, is vertically provided with a sliding groove with a T-shaped cross section, one end of the main rod, which is close to the sliding table, is fixedly connected with a sliding block matched with the sliding groove in a sliding manner, and the upper groove wall of the sliding groove is elastically connected with an elastic part between the sliding blocks.

Through adopting above-mentioned technical scheme, when the tip contact of U type depression bar and double-screw bolt and move down along with the slip table, the double-screw bolt orders about the mobile jib to the reaction force of U type depression bar and drives the slider upwards to slide in the spout, and the elastic component is compressed to produce deformation, and when the double-screw bolt approached to by the fusing, the deformation power of elastic component pushed the slider and drives mobile jib and U type depression bar and bounce off with the double-screw bolt from sinking well inner wall to reduce the damage of butt welding device when U type depression bar and double-screw bolt rigid contact as far as possible.

Further setting the following steps: recovery unit is including fixing terminal surface and level are directional under the slip table the branch of "L" font of support, branch is kept away from the one end of gag lever post is fixed with and is located the collection frame under the welder, the edgewise rigid coupling of collecting the frame has the collection pocket, it has fire prevention heat insulating cloth to collect pocket inside wall subsides.

Through adopting above-mentioned technical scheme, the double-screw bolt welds the back and drops from sinking well inner wall, falls into the collection pocket of below in, and the thermal-insulated portion of preventing fires avoids the waste heat on the double-screw bolt as far as will collect the pocket and melt and wear, has guaranteed recovery unit's validity.

Further setting the following steps: the limiting rod is sleeved with a plurality of sliding rings along the length direction of the limiting rod, and the side wall of each sliding ring is fixed with a hoop.

Through adopting above-mentioned technical scheme, welder's trachea, pipeline etc. slide through the staple bolt and connect on the gag lever post, and the slip table drives trachea, pipeline etc. also go up and down on the gag lever post when the screw rod goes up and down, avoids welder when the operation as far as possible, and its trachea or pipeline landing are fused to welder department, have reduced the potential safety hazard.

Further setting the following steps: the driving device comprises a motor fixedly connected to the upper end face of the supporting beam, the output end of the motor is coaxially and fixedly connected with a first bevel gear, and the upper end of the screw rod is coaxially and fixedly connected with a second bevel gear in meshed fit with the first bevel gear.

Through adopting above-mentioned technical scheme, starter motor, it is rotatory that its output of motor drive drives first bevel gear when rotatory, and first bevel gear drives the second bevel gear rotation of meshing adaptation with it when rotatory, and then drives the screw rod and rotate on a supporting beam, has realized the stable rotation of screw rod.

To sum up, the utility model discloses a beneficial technological effect does:

1. the welding gun is lifted in the length direction of the screw rod through the sliding table, and the welding gun is stretched into the open caisson to perform welding operation on the studs with different depths on the inner wall of the open caisson, so that a constructor is not required to go into the open caisson for operation, the potential safety hazard is reduced, the labor cost is reduced, and the construction efficiency is improved;

2. the support beam can slide and rotate on the support through the slide rail and the rotating shaft, so that the welding gun can extend into the open caisson to weld and fuse a stud in a larger area, the moving frequency of the support is reduced, and the construction efficiency is improved;

3. when the welding gun performs fusing operation on the stud, the end part, far away from the inner wall of the open caisson, of the stud is gradually pressed down by the U-shaped pressure rod, so that the welding gun can effectively aim at the unwelded part of the cross section of the stud in the welding process, the fusing speed of the stud is accelerated, and meanwhile, the gas consumption of the welding gun can be saved.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is an enlarged partial schematic view of portion A of FIG. 1;

fig. 3 is a partially enlarged schematic view of a portion B in fig. 1.

Reference numerals: 1. a support; 2. a support beam; 3. a screw; 4. a sliding table; 5. a welding gun; 6. a limiting rod; 7. a slide rail; 8. a rotating shaft; 9. an annular groove; 10. positioning plates; 11. fixing the bolt; 12. a main rod; 13. a U-shaped compression bar; 14. a chute; 15. a slider; 16. an elastic member; 17. a strut; 18. a collection frame; 19. collecting bags; 20. fireproof heat-insulating cloth; 21. a slip ring; 22. hooping; 23. a motor; 24. a first bevel gear; 25. a second bevel gear; 26. a first bearing; 27. a second bearing; 28. and (6) positioning the bolt.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1 and 3, for the utility model discloses a welding device of open caisson inner wall double-screw bolt, including support 1, support 1 up end level is fixed with first bearing 26, the coaxial fixedly connected with pivot 8 of inner circle of first bearing 26, the up end level of pivot 8 is fixed with slide rail 7 that the cross section is "C" font, slide rail 7 open-ended side up and its inside connection of sliding have a supporting beam 2, slide rail 7 up end screw thread is worn to be equipped with one end and supporting beam 2 up end contact's positioning bolt 28; the upper end face of the support 1 is fixed with a plurality of positioning pieces 10, the positioning pieces 10 are preferably three and distributed in an equidistant circumferential array with the axis of the rotating shaft 8, the circumferential wall of the rotating shaft 8 is provided with an annular groove 9 vertical to the axis of the rotating shaft, and the positioning pieces 10 are threaded through fixing bolts 11 pointing to the annular groove 9 and the axis of the annular groove 9.

After the support 1 is fixed on the ground, the rotating shaft 8 can drive the sliding rail 7 to swing in the horizontal direction, namely the supporting beam 2 penetrating in the sliding rail 7 swings, and meanwhile, when the supporting beam 2 slides in the sliding rail 7, the area which can be contacted by the end part of the supporting beam 2 is further enlarged, so that the support 1 is prevented from being frequently moved as far as possible, and unnecessary time consumption is reduced; after the position of the supporting beam 2 is adjusted, the positioning bolts 28 are rotated to enable one end of each positioning bolt close to the supporting beam 2 to be tightly abutted against the upper end face of the supporting beam 2, the supporting beam 2 is fixed in the sliding rail 7, the end portions of the fixing bolts 11 are rotated to extend into the annular groove 9 and abut against the bottom wall of the annular groove 9, the rotating shaft 8 is fixed on the support 1, and the stability of the welding device during operation is guaranteed as far as possible.

Referring to fig. 1, a supporting beam 2 keeps away from the one end of support 1 and has vertically seted up the perforation (not shown in the figure), a supporting beam 2 has second bearing 27 in the perforation rigid coupling, the inner circle coaxial fixation of second bearing 27 has vertical screw rod 3, a supporting beam 2 keeps away from the tip of support 1 and still vertically is fixed with the gag lever post 6 that is on a parallel with screw rod 3, threaded connection has slip table 4 on the screw rod 3, slip table 4 is close to the up end rigid coupling of support 1 one end and has welder 5, the other end is run through by gag lever post 6, gag lever post 6 is equipped with a plurality of sliding rings 21 along its length direction cover, sliding ring 21 lateral wall rigid coupling has the staple.

The support 1 is erected on the ground around the open caisson, so that the screw rod 3 and the limiting rod 6 extend into the open caisson, the screw rod 3 is driven to rotate, the screw rod 3 drives the sliding table 4 matched with the screw thread to move when rotating, and meanwhile, the limiting rod 6 plays a limiting role in the sliding table 4, so that the sliding table 4 moves up and down along the length direction of the screw rod 3, the position of the support beam 2 on the support 1 is adjusted, the muzzle of the welding gun 5 is aligned with the combination part of the stud and the inner wall of the open caisson, the welding gun 5 is started, and after the end part of the stud is welded and melted by the welding gun 5, the screw rod 3 falls off from the inner wall of the open caisson, so that the stud is effectively welded and melted by the welding and melting device, construction personnel do not need to go into the; the trachea, the pipeline of welder 5 etc. slide through staple bolt 22 and connect on gag lever post 6, and slip table 4 drives trachea, pipeline etc. also go up and down on gag lever post 6 when screw rod 3 goes up and down, avoids welder 5 when the operation as far as possible, and its trachea or pipeline landing are fused to welder 5 department, have further reduced the potential safety hazard.

Referring to fig. 2, the lower terminal surface elasticity that slip table 4 is close to welder 5 one end is provided with the frame of pressing that is used for pressing the double-screw bolt, press the frame including elastic connection at 4 tip of slip table and be the mobile jib 12 that the level set up, the one end rigid coupling that slip table 4 was kept away from to mobile jib 12 has opening decurrent U type depression bar 13, slip table 4 is close to welder 5's tip vertical offer the spout 14 that the cross section is "T" font, mobile jib 12 is close to the one end rigid coupling of slip table 4 has the slider 15 with the adaptation that slides 14 of spout, elastic connection has elastic component 16 between spout 14 upper groove wall and the slider 15.

When the sliding table 4 drives the welding gun 5 to move downwards, the U-shaped pressure rod 13 firstly contacts with the stud, when the welding gun 5 welds the joint of the stud and the inner wall of the open caisson, the screw rod 3 can be slowly driven to rotate so as to drive the sliding table 4 to slowly descend, the reaction force of the stud on the U-shaped pressure rod 13 drives the main rod 12 to drive the sliding block 15 to slide upwards in the sliding groove 14, and the elastic piece 16 is compressed to generate deformation; the U-shaped pressure lever 13 can effectively aim at the unwelded part of the cross section of the stud in the welding process in the process of pressing one end of the stud, which is far away from the inner wall of the open caisson, downwards, so that the fusing speed of the stud is increased, and the air consumption of the welding gun 5 can be saved; when the stud is close to being fused, the deformation force of the elastic piece 16 pushes the sliding block 15 to drive the main rod 12 and the U-shaped pressure lever 13 to bounce the stud from the inner wall of the sinking well, so that the damage to the welding device when the U-shaped pressure lever 13 is in rigid contact with the stud is reduced as much as possible.

Referring to fig. 1 and 2, the lower end face of the limiting rod 6 is further provided with a recovery device, the recovery device comprises an L-shaped supporting rod 17 which is fixed on the lower end face of the sliding table 4 and horizontally points to the support 1, one end, far away from the limiting rod 6, of the supporting rod 17 is fixed with a collecting frame 18 which is located right below the welding gun 5, one end, far away from the sliding table 4, of the collecting frame 18 is arranged into an arc shape, a collecting pocket 19 is fixedly connected to the edge of the collecting frame 18, fireproof heat-insulating cloth 20 is attached to the inner side wall of the collecting pocket 19, and the fireproof heat-insulating; the upper end face of the supporting beam 2 is provided with a driving device for driving the screw rod 3 to rotate, the driving device comprises a motor 23 fixedly connected to the upper end face of the supporting beam 2, the output end of the motor 23 is coaxially and fixedly connected with a first bevel gear 24, and the upper end part of the screw rod 3 is coaxially and fixedly connected with a second bevel gear 25 meshed and matched with the first bevel gear 24.

After the stud is welded and melted, the stud falls off from the inner wall of the caisson and falls into the collecting bag 19 below, the fireproof heat insulation part avoids the waste heat on the stud from melting the collecting bag 19 as far as possible, the effectiveness of the recovery device is guaranteed, and meanwhile, the end, close to the inner wall of the caisson, of the collecting frame 18 is set into an arc shape, so that the fitting degree of the collecting frame 18 and the inner wall of the caisson is guaranteed as far as possible, and the stud is further guaranteed to fall into the collecting bag 19.

After the fusing and collection of a certain stud is completed, the locking of the positioning bolt 28 on the supporting beam 2 is released, the supporting beam 2 is moved to enable the collecting frame 18 to be away from the outermost end of the bolt below, the motor 23 is started, the motor 23 drives the output end of the motor to rotate, the first bevel gear 24 drives the second bevel gear 25 which is meshed with the first bevel gear to rotate when rotating, the screw rod 3 is further driven to rotate on the supporting beam 2, the sliding table 4 drives the collecting frame 18 to move downwards, after the stud passes through the lower part, the supporting beam 2 is moved again to enable the cambered surface of the collecting frame 18 to be in contact with the inner wall of the open caisson, the motor 23 is started again, the position of the sliding table 4 is finely adjusted, the muzzle of the welding gun 5 is aligned with the joint.

The implementation principle and the beneficial effects of the embodiment are as follows:

fix support 1 on the peripheral subaerial of open caisson, it is rotatory to drive screw rod 3 through drive arrangement, under the limiting displacement of gag lever post 6 to slip table 4, screw rod 3 drives slip table 4 of screw thread adaptation with it and goes up and down along its length direction when rotatory, the position of adjustment supporting beam 2 on support 1, make welder 5 aim at double-screw bolt and open caisson inner wall joint part, welder 5 opens welder 5, after welder 5 welds the double-screw bolt tip, screw rod 3 drops and transfers into the recovery unit of below from the inner wall of open caisson, the effective welding and the collection of double-screw bolt of welding device has been realized, need not constructor and go down to the interior operation of open caisson, the potential safety hazard has been reduced, the human cost has also been reduced, the efficiency of construction has been improved.

The embodiment of this specific implementation mode is the preferred embodiment of the present invention, not limit according to this the utility model discloses a protection scope, so: all equivalent changes made according to the structure, shape and principle of the utility model are covered within the protection scope of the utility model.

Claims

1. The utility model provides a weld melting device of open caisson inner wall double-screw bolt which characterized in that: including support (1), support (1) up end swing joint has a supporting beam (2), it keeps away from to prop up supporting beam (2) the vertical rotation of one end of support (1) is connected with screw rod (3), it is used for the drive to be provided with on supporting beam (2) screw rod (3) pivoted drive arrangement, threaded connection has slip table (4) on screw rod (3), slip table (4) are close to the one end rigid coupling of support (1) has welder (5), it is close to prop up supporting beam (2) the tip rigid coupling of screw rod (3) has and is on a parallel with gag lever post (6) of screw rod (3), gag lever post (6) run through slip table (4) are kept away from the one end of welder (5), the terminal surface still is provided with the recovery unit who is used for collecting the double-screw bolt under slip table (4).

2. The welding and fusing device for the stud on the inner wall of the open caisson according to claim 1, wherein: the horizontal rotation of support (1) up end be connected with slide rail (7) of the adaptation that slides of supporting beam (2), slide rail (7) transversal personally submit "C" font, slide rail (7) up end screw thread wear to be equipped with one end with positioning bolt (28) of supporting beam (2) up end contact.

3. The welding and fusing device for the stud on the inner wall of the open caisson according to claim 2, wherein: the end face rigid coupling has under slide rail (7) with pivot (8) that support (1) up end rotated and is connected, ring channel (9) of perpendicular to its axis are seted up to pivot (8) perisporium, support (1) up end is fixed with a plurality of spacer (10), the screw thread is worn to be equipped with the sensing on spacer (10) fixing bolt (11) of ring channel (9).

4. The welding and fusing device for the stud on the inner wall of the open caisson according to claim 3, wherein: slip table (4) are close to the lower terminal surface elasticity of welder (5) one end is provided with the frame of pressing that is used for pressing the double-screw bolt, press the frame including elastic connection in mobile jib (12) that just is the level setting on slip table (4), mobile jib (12) are kept away from the one end rigid coupling of slip table (4) has opening decurrent U type depression bar (13).

5. The welding and fusing device for the stud on the inner wall of the open caisson according to claim 4, wherein: the end part of the sliding table (4) close to the welding gun (5) is vertically provided with a sliding groove (14) with a T-shaped cross section, the main rod (12) is close to one end of the sliding table (4) and fixedly connected with a sliding block (15) matched with the sliding groove (14) in a sliding mode, and the upper groove wall of the sliding groove (14) is elastically connected with an elastic piece (16) between the sliding blocks (15).

6. The welding and fusing device for the stud on the inner wall of the open caisson according to claim 1, wherein: recovery unit is including fixing terminal surface and level point to under slip table (4) branch (17) of "L" font of support (1), branch (17) are kept away from the one end of gag lever post (6) is fixed with and is located collection frame (18) under welder (5), the edgewise rigid coupling of collecting frame (18) has collection pocket (19), it has fire prevention heat insulating cloth (20) to collect pocket (19) inside wall subsides.

7. The welding and fusing device for the stud on the inner wall of the open caisson according to claim 1, wherein: the limiting rod (6) is sleeved with a plurality of sliding rings (21) along the length direction of the limiting rod, and the side walls of the sliding rings (21) are fixed with hoops (22).

8. The welding and fusing device for the stud on the inner wall of the open caisson according to claim 1, wherein: the driving device comprises a motor (23) fixedly connected to the upper end face of the supporting beam (2), a first bevel gear (24) is fixedly connected to the output end of the motor (23) in a coaxial mode, and a second bevel gear (25) meshed and matched with the first bevel gear (24) is fixedly connected to the upper end portion of the screw rod (3) in a coaxial mode.