CN111806506A

CN111806506A - Construction transport vechicle

Info

Publication number: CN111806506A
Application number: CN202010760537.3A
Authority: CN
Inventors: 蒙方葵
Original assignee: 蒙方葵
Current assignee: YELLOW RIVER CONSERVATION GROUP Co.,Ltd.
Priority date: 2020-07-31
Filing date: 2020-07-31
Publication date: 2020-10-23
Anticipated expiration: 2040-07-31
Also published as: CN113665619A; CN113682340A; CN111806506B

Abstract

The invention provides a transport vehicle for building construction, which effectively solves the problems that the existing transport vehicle cannot brake in time after losing traction force and is unsafe in use; the technical scheme for solving the problem is that the track comprises a rail, wherein a flat plate is arranged above the rail, a rotating shaft is arranged below the flat plate, wheels are arranged at two ends of the rotating shaft, an inner shell is arranged outside the wheels, an outer shell is sleeved on the inner shell, a first bevel gear is arranged on one side of the outer shell, double-head screws are arranged at two ends of the flat plate, and a second bevel gear is arranged on the double-head screws; a guide rail is arranged on the lower end face of the flat plate, a sliding block is arranged on the guide rail, a cross rod is arranged below the flat plate, a first connecting rod is arranged on the sliding block, and a U-shaped plate is fixed below the sliding block; the upper side of the flat plate is provided with a carriage, the lower ends of the left and right side plates of the carriage are provided with a plurality of disc-shaped gears, a first rack is fixed on the flat plate, a second rack is arranged above the first rack, a first movable plate is arranged on the upper side of the rear end of the carriage, a second movable plate is hinged to the rear side of the flat plate, and the lower end of the first movable plate is hinged to the middle of the second movable plate through a second connecting rod.

Description

Construction transport vechicle

Technical Field

The invention relates to the technical field of construction engineering construction, in particular to a construction transport vehicle.

Background

At present, many electric rail cars are adopted to transport tunnel earthwork, the scheme is superior to a manual scheme in time cost and labor cost, and especially the safety is high. Under the condition of large gradient, manufacturers generally recommend a scheme of using a winch to pull the rail car. Track construction conveyer is mainly for hoist engine traction trolley, in order to prevent the dolly from falling, what generally adopted among the prior art is to increase wire rope and add the winch reel, however this kind of mode also has the drawback of increaseing, for example, every wire rope's atress is inconsistent, the dolly appears crooked, certain or several atress fracture excessively greatly, remaining wire rope atress increase in the twinkling of an eye is tightened, the fracture appears very easily, cause the dolly to descend fast along the track, cause serious threat to constructor and construction platform below, even injure life, if there is inflammable gas below, that consequence can't imagine.

Most of the existing trolleys are provided with simple braking or speed limiting devices, so that the speed of the trolleys can be prevented from being continuously increased when steel wire ropes are broken, loss is reduced, but the speed limiting devices can only limit the speed of the trolleys below a certain numerical value, but the speed limiting devices do not directly brake the brakes, the trolleys can fall along the slope, and serious accidents can be caused if heavy objects or people exist on the trolleys.

Patent document (CN 210852463U) discloses an anti-falling ramp trolley, which utilizes the traction force of a steel wire rope to control the state of a braking member, but has obvious defects in practical application, for example, in large underground building construction, a track of the trolley is used for temporarily transporting earthwork or building materials, and a part of the track can be built up and down in an up-and-down fluctuating shape according to needs, in the fluctuating stage of the track, the traction force of the steel wire rope to the trolley is unstable, so that the braking member is in direct frequent collision or frictional contact with the surface of a steel rail, loss exists in the trolley, and the upper surface of the rail is also greatly lost, which affects the service life of the rail; after a period of time, the loss of the braking part is quite serious, and the braking part cannot be ensured to provide enough friction force under the condition that the steel wire rope is broken, so that the braking is finally failed, and the trolley can slide downwards; besides, the contact surface in this patent is also extremely limited, increasing the risk of brake failure.

In conclusion, the transport vehicle used in building construction in the prior art is not safe because of few necessary emergency braking devices, and cannot fundamentally solve the risk that the transport vehicle falls down due to loss of traction force after the lifting equipment fails or the steel wire rope is broken.

Disclosure of Invention

Aiming at the situation, the invention provides a transport vehicle for building construction to overcome the defects of the prior art, and effectively solves the problems that the existing transport vehicle cannot brake in time after losing traction force and is unsafe in use.

The technical scheme includes that the rail comprises a rail, a horizontal flat plate is arranged above the rail, two horizontal rotating shafts which can rotate are arranged below the flat plate, wheels are arranged at two ends of each rotating shaft and can roll along a rail, a cylindrical inner shell which is coaxial with the wheels is fixed on the outer sides of the wheels, an outer shell is sleeved on the inner shell, when the rotating speed of the inner shell exceeds a certain value, the inner shell can drive the outer shell to rotate together, the outer shell is fixed on the flat plate in a rotating mode, a first bevel gear is fixed on one side, away from the wheels, of the outer shell, double-head screws which are arranged in the front-back direction are arranged on the lower sides of two ends of the flat plate, the double-head screws are fixed below the flat plate in; a guide rail parallel to the rotating shaft is fixed on the lower end face of the flat plate, sliding blocks sliding along the left and right directions are arranged on the guide rail, two transverse rods parallel to the rotating shaft are arranged below the flat plate and are symmetrical front and back, the rotation of the double-end screw can control the two transverse rods to be close to or away from each other, two first connecting rods are hinged to each sliding block, the other ends of the first connecting rods are hinged to the middle parts of the transverse rods, the two transverse rods are close to each other to enable the two sliding blocks to be away from each other along the guide rail, a U-shaped plate with a downward opening is fixed below each sliding block, and the two sliding;

the utility model discloses a platform, including dull and stereotyped, dull and stereotyped front side, the flat board, the carriage is installed to dull and stereotyped upside, the lower extreme of carriage left and right sides board articulates there is a plurality of dish type gears, be fixed with the first rack that corresponds with dish type gear on the flat board, there is the second rack with dish type gear meshing above the first rack, the second rack can only be along the back-and-forth movement, carriage rear end upper side articulates there is first fly leaf, dull and stereotyped rear side articulates there is the second fly leaf of level form, install the extension spring between second fly leaf middle part and the carriage, first fly leaf lower extreme and second fly leaf middle part are together articulated through the second connecting rod, when the second rack rearward movement has promoted first fly leaf and rotates round the pin joint, first.

The trolley has a smart structure, and can be emergently braked under the action of the trolley when traction force is lost, so that the trolley can be firmly fixed on a track, the construction safety is fundamentally ensured, and the falling risk is avoided.

Drawings

FIG. 1 is a front cross-sectional view of the present invention.

FIG. 2 is a side cross-sectional view of the present invention.

Fig. 3 is a schematic connection diagram (bottom view) of the core component of the present invention.

Fig. 4 is a sectional view taken along line a-a of fig. 2.

Fig. 5 is a use state diagram of the present invention.

Fig. 6 is a schematic view of the inner case, the outer case, the first pawl, and the second pawl in an initial state according to the present invention.

Fig. 7 is a state diagram of the first pawl and the second pawl when the inner shell drives the outer shell to rotate according to the present invention.

FIG. 8 is a view showing the construction of a double-headed screw and a second bevel gear in the present invention.

FIG. 9 is a schematic view showing the connection of some parts according to the present invention.

Detailed Description

The following description will explain embodiments of the present invention in further detail with reference to the accompanying drawings.

As shown in fig. 1 to 9, the present invention includes a rail, a horizontal plate 1 is provided above the rail, two horizontal rotating shafts 2 capable of rotating are provided below the plate 1, wheels 3 are provided at two ends of the rotating shafts 2, the wheels 3 can roll along a rail, a cylindrical inner shell 4 coaxial with the wheels is fixed outside the wheels, an outer shell 5 is sleeved on the inner shell 4, when the rotating speed of the inner shell 4 exceeds a certain value, the inner shell 4 can drive the outer shell 5 to rotate together, the outer shell 5 is rotationally fixed on the plate 1, a first bevel gear 6 is fixed on one side of the outer shell 5 far away from the wheels 3, a double-headed screw 7 arranged along the front-back direction is provided at the lower side of each end of the plate 1, the double-headed screw 7 is rotationally fixed below the plate 1, and a second bevel gear 8 engaged with the first bevel gear 6 is fixed on the double; a guide rail 9 parallel to the rotating shaft 2 is fixed on the lower end face of the flat plate 1, a sliding block 10 sliding along the left-right direction is arranged on the guide rail 9, two cross rods 11 parallel to the rotating shaft 2 are arranged below the flat plate 1, the two cross rods 11 are symmetrical front and back, the rotation of the double-head screw 7 can control the two cross rods 11 to approach or separate from each other, two first connecting rods 12 are hinged on each sliding block 10, the other ends of the first connecting rods 12 are hinged with the middle parts of the cross rods 11, the two cross rods 11 approach to each other to enable the two sliding blocks 10 to separate from each other along the guide rail 9, a U-shaped plate 13 with a downward opening is fixed below each sliding block 10, and when the two sliding;

the utility model discloses a platform, including dull and stereotyped 1, the dull and stereotyped 1 upside install the carriage, the lower extreme of the board of carriage left and right sides articulates has a plurality of dish type gears 14, be fixed with the first rack 15 that corresponds with dish type gear 14 on the dull and stereotyped 1, there is the second rack 16 with the meshing of dish type gear 14 above the first rack 15, second rack 16 can only be along the back-and-forth movement, carriage rear end upside articulates has first fly leaf 17, the board 1 rear side articulates has horizontal second fly leaf 18, install the extension spring between second fly leaf 18 middle part and the carriage, first fly leaf 17 lower extreme and second fly leaf 18 middle part are articulated together through the second connecting rod, when second dish type gear 14 moves backward and has the first fly leaf 17 of promotion to rotate around the pin joint, first fly leaf 17 lower extreme makes the side down tilt behind the second fly leaf 18 through the second connecting rod.

In order to make the two U-shaped plates 13 clamp the rail, the side plates of the U-shaped plates 13 are provided with long blocks 19 corresponding to the rail, when the two sliders 10 drive the U-shaped plates 13 to move away from each other, the two long blocks 19 on the same side can clamp the rail, so that the flat plate 1 is fixed on the rail, and the long blocks 19 are covered with rubber layers.

After exceeding a definite value in order to realize 4 rotational speeds of inner shell, no matter the inner shell 4 can both drive shell 5 and rotate together in corotation or reversal, convenient rescue, the lateral wall of inner shell 4 on open and to have a plurality of notches 20, it has a plurality of first pawls 21 to articulate through the torsional spring in the notch 20, one of keeping away from the pin joint of first pawl 21 is served and is had the inclined plane, there is protruding formation couple on the inclined plane, there are a plurality of second pawls 22 that are the circumference equipartition on the 5 inside walls of shell, second pawl 22 is in the same place through the torsional spring is articulated with shell 5, one of keeping away from the pin joint of second pawl 22 is served and is had the protruding buckle that forms, when inner shell 4 rotates at a high speed, first pawl 21 rotates to the outside, the inclined plane on the first pawl 21 makes first pawl.

For installation double-threaded screw 7, double-threaded screw 7 both ends have first mounting panel 23, double-threaded screw 7's both ends run through first mounting panel 23, install the bearing between first mounting panel 23 and the double-threaded screw 7.

In order to realize that the rotation of the double-end screw 7 can control the two cross rods 11 to be close to or far away from each other, the two ends of the double-end screw 7 are sleeved with the cylinders 24, the cylinders 24 are fixed with the corresponding cross rods 11, and when the double-end screw 7 rotates, the double-end screw 7 can drive the two cross rods 11 to be close to or far away from each other through the cylinders 24.

In order to avoid the mutual separation after the cross rod 11 recovers the original position in rescue, only the middle part of the double-head screw 7 has a threaded structure, a pressure spring is arranged between the cylinder 24 and the first mounting plate 23, the pressure spring can push the cylinder 24 upwards towards the part of the double-head screw 7 with the threaded structure, so that the threads on the cylinder 24 are kept in contact with the threads on the double-head screw 7, when the cylinder 24 is positioned at the part of the double-head screw 7 with no threads at the two ends, the double-head screw 7 can rotate forwards to drive the two cylinders 24 on the double-head screw 7 to be close to each other, and at the moment, the double-head nut rotates backwards.

In order to fix the shell 5 on the lower side of the flat plate 1 in a rotating way, the lower end of the flat plate 1 is provided with a vertical second mounting plate 25, the central shaft of the first bevel gear 6 penetrates through the second mounting plate 25, and a bearing is arranged between the second mounting plate 25 and the central shaft of the first bevel gear 6.

In order to install the rotating shaft 2, a fixing block 26 corresponding to the rotating shaft 2 is fixed at the lower end of the flat plate 1, the rotating shaft 2 penetrates through the fixing block 26, and a bearing is installed between the rotating shaft 2 and the fixing block 26.

In order to mount the second rack 16 and realize that the second rack 16 can only move back and forth, the second rack 16 is provided with a sliding groove which is arranged along the front and back direction, a plurality of pins 27 are arranged in the sliding groove, one end of each pin 27 is fixed with the carriage, the other end of each pin 27 is provided with an annular bulge, and the annular bulge ensures that the second rack 16 is not separated from the pins 27.

In order to fix the carriage and the flat plate 1 together under normal conditions, a plurality of positioning pins 28 are arranged above the flat plate 1, a plurality of positioning holes corresponding to the positioning pins 28 are formed in the lower end face of the carriage, the positioning pins 28 are arranged in the positioning holes, and when the positioning pins 28 are stressed excessively, the positioning pins 28 are broken.

It should be noted that, in order to prevent the flat plate 1 from completely separating from the carriage in the case of the positioning pin 28 being broken, the lower side of the front end of the carriage is connected with the front end of the flat plate 1 through an iron chain; in order to enable the first pawl 21 to smoothly swing outwards through the notch 20, a plurality of limiting rods corresponding to the first pawl 21 are arranged in the inner shell 4, under the normal condition, the first pawl 21 is in contact with the limiting rods under the action of a torsion spring, and when the centrifugal force applied to the first pawl 21 is too large, the first pawl 21 swings out through the notch 20 and is in close contact with the second pawl 22 under the action of an inclined surface on the first pawl 21, so that the outer shell 5 and the inner shell 4 rotate together.

In the scheme, the track is supposed to be in a slope with a high front part and a low rear part, when the device is normally used, the positioning pin 28 is arranged in the corresponding positioning hole, the flat plate 1 is fixedly connected with the carriage, the movable plate is in a horizontal shape under the action of the tension spring, the wheel 3 rotates at a low speed under the traction of the steel wire of the winch, the first pawl 21 and the second pawl 22 are separated from each other, when the steel wire rope is broken, the trolley slides backwards along the track, when the trolley moves backwards rapidly, the wheel 3 rolls at a high speed along the track, the wheel 3 drives the inner shell 4 on the wheel 3 to rotate, when the wheel 3 is at an excessive speed and the centrifugal force applied to the first pawl 21 is too large, the first pawl 21 swings out through the notch 20 and is in tight contact with the second pawl 22 under the action of the inclined plane on the first pawl, so that the outer shell 5 and the inner shell 4 rotate together, the outer shell 5 rotates to drive the second bevel, the two cross rods 11 are enabled to approach each other by positive rotation of the double-headed screw 7, the two sliding blocks 10 are enabled to be away from each other along the guide rail 9 by the cross rods 11 through the first connecting rods 12 on the cross rods, the sliding blocks 10 drive the U-shaped plates 13 on the sliding blocks to move, the long strip blocks 19 on the same side can clamp the rail tightly, and at the moment, the flat plate 1 is fixed on the rail and is not moved to wait for rescue.

In the above process, when a heavy object is in the carriage, after the flat plate 1 is fixed, the carriage still has large inertia, if the inertia is large enough, the positioning pin 28 is broken due to excessive stress, the breakage of the positioning pin 28 can counteract a part of impulsive force, then the carriage moves towards the rear side along the flat plate 1, the disk-shaped gear 14 on the carriage rolls on the first rack 15, the disk-shaped gear 14 drives the second rack 16 to move towards the rear, the second rack 16 props against the first movable plate 17 in the process of moving towards the rear, the lower end of the first movable plate 17 enables the right end of the second movable plate 18 to incline downwards and touch the ground through the second connecting rod, and after the rear end of the second movable plate 18 is subjected to the reaction provided by the ground, the inclined supporting force is provided for the front end of the carriage through the first connecting rod 12, the movable rod and the second rack 16, so that the carriage can be effectively prevented from sliding forwards and the carriage.

After the flat plate 1 and the carriage are fixed, waiting for rescue, and after the rescue workers arrive, fixedly installing a new steel wire rope again, then the trolley is pulled upwards, at the moment, the wheels 3 roll upwards, the end parts of the first pawls 21 and the second pawls 22 are tightly buckled and pulled together, the wheels 3 drive the inner shell 4 to rotate, the inner shell 4 rotates to drive the outer shell 5 to rotate through the first pawls 21 and the second pawls 22, the outer shell 5 rotates to drive the second bevel gear 8 to rotate through the first bevel gear 6, the second bevel gear 8 drives the double-headed screw 7 to rotate reversely, the two cross rods 11 move to one side away from each other through the cylinders 24 due to the rotation of the screws, the long blocks 19 on the two U-shaped plates 13 are gradually away from the rail until the cylinders 24 are positioned on the parts without threads of the double-headed screw 7, the cross rods 11 are restored to the original state, and after the trolley is pulled to a safe position, the whole trolley is comprehensively checked and.

The invention has the outstanding advantages and remarkable progress that:

1. the invention utilizes the two U-shaped plates 13 which move oppositely to enable the long blocks 19 to clamp the rail, and then enables the flat plate 1 dropping at high speed to be fixed on the rail, thereby fundamentally ensuring that the trolley is prevented from dropping under the action of no traction force, and further ensuring the construction safety.

2. According to the invention, as long as the wheel 3 rotates too fast at a certain time, the first pawls 21 and the second pawls 22 are matched under the action of centrifugal force, and then the outer shell 5 rotates along with the inner shell 4, when rescuers arrive and are pulled upwards, the second bevel gear 8 rotates reversely to enable the double-headed screw 7 to rotate reversely, so that the cross rod 11 is restored to the original state, the rescue process is simplified, and the rescue efficiency is improved.

3. According to the rail clamp, a small force is converted into a large clamping force by using the threaded structure, so that the trolley and a rail can be effectively and firmly fixed, and the trolley is prevented from continuously falling.

4. According to the invention, the first movable plate 17, the second movable plate 18 and the second connecting rod provide an oblique upward supporting force for the carriage, so that the carriage is effectively prevented from overturning under the inertia effect, and the safety of personnel or articles in the carriage is ensured.

5. According to the invention, the inertia of the carriage is positioned and offset by a part, then the carriage moves backwards relative to the flat plate 1, and the plate-shaped gear 14 rolls on the first rack 15, so that the backward movement distance of the second rack 16 is greater than the movement distance of the carriage, the rear end of the second rack 16 can be ensured to prop against the first movable plate 17, and further the first movable plate 17, the second movable plate 18 and the second connecting rod can provide supporting force for the carriage, and the carriage can be effectively prevented from overturning.

6. When the invention is implemented, in order to increase the braking force, the length and the width of the long block 19 can be adjusted to ensure that enough braking force is provided for the falling trolley.

Compared with the prior art, the trolley can be emergently braked under the action of the trolley when traction force is lost, so that the trolley can be firmly fixed on the track, the construction safety is fundamentally ensured, and the risk of falling is avoided.

Claims

1. A transport vehicle for building construction is characterized by comprising rails, a horizontal flat plate (1) is arranged above the rails, two horizontal rotating shafts (2) which can rotate are arranged below the flat plate (1), wheels (3) are arranged at two ends of each rotating shaft (2), the wheels (3) can roll along a track, a cylindrical inner shell (4) which is coaxial with the wheels is fixed on the outer sides of the wheels, an outer shell (5) is sleeved on the inner shell (4), when the rotating speed of the inner shell (4) exceeds a certain value, the inner shell (4) can drive the outer shell (5) to rotate together, the outer shell (5) is rotationally fixed on the flat plate (1), a first bevel gear (6) is fixed on one side, away from the wheels (3), of the outer shell (5), double-threaded screws (7) arranged in the front-back direction are arranged on the lower sides of two ends of the flat plate (1), the double-threaded screws (7) are rotationally fixed below the flat plate (1), and second bevel gears (8) meshed with the first bevel gears (6) are fixed on the double-threaded screws (7); the lower end face of the flat plate (1) is fixedly provided with a guide rail (9) parallel to the rotating shaft (2), the guide rail (9) is provided with a sliding block (10) which slides along the left-right direction, two cross rods (11) parallel to the rotating shaft (2) are arranged below the flat plate (1), the two cross rods (11) are symmetrical front and back, the two cross rods (11) can be controlled to be close to or away from each other through rotation of the double-headed screw (7), each sliding block (10) is hinged with two first connecting rods (12), the other end of each first connecting rod (12) is hinged with the middle part of each cross rod (11), the two cross rods (11) are close to each other to enable the two sliding blocks (10) to be away from each other along the guide rail (9), a U-shaped plate (13) with a downward opening is fixed below each sliding block (10), and;

a carriage is arranged on the upper side of the flat plate (1), a plurality of disc-shaped gears (14) are hinged to the lower ends of the left and right side plates of the carriage, a first rack (15) corresponding to the disc-shaped gears (14) is fixed on the flat plate (1), a second rack (16) meshed with the disc-shaped gears (14) is arranged above the first rack (15), the second rack (16) can only move back and forth, a first movable plate (17) is hinged to the upper side of the rear end of the carriage, a horizontal second movable plate (18) is hinged to the rear side of the flat plate (1), a tension spring is arranged between the middle part of the second movable plate (18) and the carriage, the lower end of the first movable plate (17) is hinged to the middle part of the second movable plate (18) through, when the second disk-shaped gear (14) moves backwards and pushes the first movable plate (17) to rotate around the hinge point, the lower end of the first movable plate (17) enables the rear side of the second movable plate (18) to incline downwards through a second connecting rod.

2. A construction trolley according to claim 1, wherein the U-shaped plates (133) have strips (19) on their side walls corresponding to the rails, and when the U-shaped plates (133) are moved away from each other by the two sliders (10), the two strips (19) on the same side clamp the rails, so that the plate (1) is fixed to the rails, and the strips (1919) are covered with a rubber layer.

3. The construction engineering truck as claimed in claim 1, wherein the side wall of the inner shell (4) is provided with a plurality of notches (20), the notches (20) are internally hinged with a plurality of first pawls (21) through torsion springs, one end of each first pawl (21) far away from the hinged point is provided with an inclined surface, each inclined surface is provided with a protrusion to form a hook, the inner side wall of the outer shell (5) is provided with a plurality of second pawls (22) which are uniformly distributed in the circumferential direction, the second pawls (22) are hinged with the outer shell (5) through torsion springs, one end of each second pawl (22) far away from the hinged point is provided with a protrusion to form a buckle, when the inner shell (4) rotates at a high speed, the first pawls (21) rotate outwards, and the inclined surfaces on the first pawls (21) enable the first pawls (21) and the second pawls (22) to be matched together.

4. The construction transport vehicle as claimed in claim 1, wherein the two ends of the double-threaded screw (7) are provided with first mounting plates (23), the two ends of the double-threaded screw (7) penetrate through the first mounting plates (23), and a bearing is arranged between the first mounting plates (23) and the double-threaded screw (7).

5. The construction transport vehicle as claimed in claim 1, wherein the two ends of the double-threaded screw (7) are sleeved with cylinders (24), the cylinders (24) are fixed with the corresponding cross bars (11), and when the double-threaded screw (7) rotates, the double-threaded screw (7) can drive the two cross bars (11) to approach or separate from each other through the cylinders (24).

6. The construction transport vehicle as claimed in claim 1, wherein only the middle part of the double-head screw (7) has a threaded structure, a pressure spring is installed between the cylinder (24) and the first mounting plate (23), the pressure spring can push the cylinder (24) upwards towards the part of the double-head screw (7) with the threaded structure, so that the threads on the cylinder (24) are kept in contact with the threads on the double-head screw (7), when the cylinder (24) is located at a part where the two ends of the double-head screw (7) have no threads, the double-head screw (7) can rotate forward to drive the two cylinders (24) on the cylinder to approach each other, and at the moment, the double-head nut rotates backward to prevent the two cylinders (24) from moving.

7. A construction vehicle according to claim 1, wherein the lower end of the plate (1) is provided with a vertical second mounting plate (25), the central axis of the first bevel gear (6) passes through the second mounting plate (25), and a bearing is arranged between the second mounting plate (25) and the central axis of the first bevel gear (6).

8. The construction transport vehicle as claimed in claim 1, wherein a fixing block (26) corresponding to the rotating shaft (2) is fixed at the lower end of the flat plate (1), the rotating shaft (2) penetrates through the fixing block (26), and a bearing is installed between the rotating shaft (2) and the fixing block (26).

9. The construction vehicle as claimed in claim 1, wherein the second rack (16) has a sliding groove arranged in a front-rear direction, the sliding groove has a plurality of pins (27), one end of the pin (27) is fixed to the carriage, the other end of the pin (27) has an annular protrusion, and the annular protrusion prevents the second rack (16) from being separated from the pin (27).

10. The construction transport vehicle as claimed in claim 1, wherein a plurality of positioning pins (28) are arranged above the flat plate (1), a plurality of positioning holes corresponding to the positioning pins (28) are formed in the lower end surface of the carriage, the positioning pins (28) are arranged in the positioning holes, and when the positioning pins (28) are excessively stressed, the positioning pins (28) are broken.