Combined aerial work platform scissor fork type lifting limiting mechanism and working method
Technical Field
The invention relates to an aerial work platform, in particular to a combined aerial work platform scissor fork type lifting limiting mechanism and a working method.
Background
The aerial working platform is an advanced aerial working machine, can greatly improve the working efficiency, safety and comfort of aerial constructors, reduces the labor intensity and has been widely applied in developed countries. The use of the aerial work platform in China is wider, such as the maintenance of original general municipal street lamps, the pruning of garden trees and the like, and along with the rapid development of the economy in China, the requirements of engineering construction, industrial installation, equipment maintenance, factory building maintenance, shipbuilding, electric power, municipal administration, airports, communication, gardens, traffic and the like on the aerial work platform are continuously increased.
The lifting operation of the scissor type lifting platform is strictly required, and once the lifting operation is incorrect, larger potential safety hazards such as platform shaking, whole vehicle overturning, fork arm instability and the like can appear in the operation process, so that serious personal and economic losses are caused, and real-time monitoring is very necessary to be carried out on the lifting operation of the platform in a hiding manner.
The existing method comprises the following steps: the limit switch is arranged on the chassis, then the slide block is driven by the scissors to move to a certain position on the chassis to trigger the limit switch to stop the scissors from continuously ascending, when the scissors descend, another limit switch is arranged on the chassis, then one limit plate on the scissors is used, when the scissors descend to a certain height, the limit plate touches the other limit switch to enable the scissors to stop briefly, and then the scissors continue to decelerate and descend until the scissors shrink. Although the lifting operation of the platform can be monitored in real time in design, the limit switch is relatively scattered, a plurality of limit protection covers are required to be installed, and the adjustment and maintenance are inconvenient.
Therefore, there is a need for an improved real-time monitoring limit switch mechanism for lifting operation of an aerial work platform, and a combined aerial work platform scissor lift limit mechanism and operating method thereof that overcomes the above-mentioned drawbacks and deficiencies of the prior art.
Disclosure of Invention
The invention aims to provide a combined scissor type lifting limiting mechanism of an aerial work platform and a working method thereof, which have the advantages of simple structure, convenience in installation and higher reliability and durability, and further ensure the use safety of the aerial work platform.
The invention provides a combined scissor type lifting limiting mechanism of an aerial work platform, which comprises a first connecting shaft penetrating between scissor forks and adjacent to a chassis, and a connecting rod arranged in the middle of the scissor forks, wherein one end of the connecting rod is connected with the first connecting shaft, the other end of the connecting rod is connected with a second connecting shaft pivoted with the chassis through a pin joint, the lifting limiting mechanism also comprises a limiting device and an angle sensor, the limiting device penetrates through the connecting shafts and is arranged on two sides of the connecting rod, and the angle sensor is arranged on the outer side of the second connecting shaft, and the other end of the angle sensor is connected with the side face of the connecting rod.
Preferably, the limiting device comprises a first limiting switch and a first cam mechanism which are fixedly arranged on one side of the connecting rod, and also comprises a second limiting switch and a second cam mechanism which are fixedly arranged on the other side of the connecting rod; the first cam mechanism penetrates through the first connecting shaft, and a boss of the first cam mechanism is arranged towards the second connecting shaft; the second cam mechanism penetrates through the connecting shaft, and a boss of the second cam mechanism faces to a position which is connected with the first connecting shaft and the second connecting shaft and rotates clockwise for 60 degrees; the first limit switch is fixedly arranged on the side surface of the connecting rod, and the roller is abutted against the first cam mechanism; the second limit switch is fixedly arranged on the side face of the connecting rod, and the roller wheel of the second limit switch is abutted against the second cam mechanism.
Preferably, the bosses of the first cam mechanism and the second cam mechanism are smaller than the minimum outer diameter size, and a smooth curved surface is arranged on the bosses for rolling the roller of the first limit switch or the second limit switch.
Preferably, the second connecting shaft penetrates through the first support on the chassis, the angle sensor comprises a fixing part and a movable part which extends along the fixing part and can rotate, the fixing part is located on the axis extension line of the second connecting shaft and is arranged on the outer side face of the first support, the movable part is connected with the second support, and the other end of the second support is fixed with the side face of the connecting rod.
Preferably, the section of the second support is in a Z-shaped structure, and the installation direction of the second support is the same as the length extension direction of the connecting rod.
Preferably, the angle sensor is disposed adjacent to the first limit switch and the first cam side.
The invention also provides a working method of the combined overhead working platform scissor fork type lifting limiting mechanism, which is characterized by comprising the following steps of:
when the scissors are lifted up:
1) The operator presses a lifting button, and the hydraulic system pressurizes the hydraulic lifting oil cylinder, so that the stroke of the lifting oil cylinder is increased and the scissor fork is driven to lift;
2) The scissors are lifted to enable the first connecting shaft, the second connecting shaft and the connecting rod to move relatively;
3) The first connecting shaft rotates anticlockwise relative to the connecting rod, and when the boss of the first cam mechanism touches the roller of the first limit switch, the roller of the first limit switch is pressed down, and the first limit switch starts to work;
4) The lifting oil cylinder of the aerial working platform normally works until the lifting oil cylinder approaches to the maximum stroke, the boss of the first cam mechanism is separated from the first limit switch, the roller of the first limit switch is restored to a natural state, the first limit switch stops working, and the hydraulic system of the aerial working platform stops supplying oil to the lifting oil cylinder;
when the scissors are lowered:
5) The operator presses down the descending button, and the hydraulic system releases pressure to the hydraulic lifting oil cylinder, so that the stroke of the lifting oil cylinder is reduced and the scissor fork is driven to descend;
6) When the scissors descend, the first connecting shaft, the second connecting shaft and the connecting rod move relatively;
7) The first connecting shaft rotates clockwise relative to the connecting rod, and when the boss of the second cam structure touches the roller of the second limit switch, the roller of the second limit switch is pressed down, and the second limit switch starts to work;
8) The lifting cylinder stops releasing pressure and the descending stops.
Compared with the prior art, the combined scissor type lifting limiting mechanism for the aerial work platform provided by the invention adopts the limiting device capable of limiting when the scissor rises or falls, and adopts the angle sensor to monitor the whole process, so that the combined scissor type lifting limiting mechanism for the aerial work platform is simple in structure, convenient to install, high in reliability and durability, and further ensures the use safety of the aerial work platform. The invention also provides a working method of the combined overhead working platform scissor fork type lifting limiting mechanism.
Drawings
FIG. 1 is a schematic view of a combined overhead working platform scissor lift limiting mechanism according to the present invention;
FIG. 2 is a schematic working diagram of a first limit switch and a first cam mechanism when a scissor fork of a combined overhead working platform scissor fork type limit mechanism provided by the invention rises;
fig. 3 is a schematic working diagram of the second limit switch and the second cam mechanism when the scissor fork of the combined scissor fork type lifting limit mechanism of the aerial work platform provided by the invention descends.
In the accompanying drawings:
1-a set screw; 2-a first cam mechanism; 3-a first limit switch; 4-connecting rods; 5-a set screw; 6-a second cam mechanism; 7-a second limit switch; 8-a bolt; 9-a gasket; 10-nuts; 11-a second support; 12-an angle sensor; 13-a first support; 14-a first connecting shaft; 15-a second connecting shaft.
Detailed Description
The invention will be described in detail below with reference to the drawings in connection with embodiments. It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other. For convenience of description, the words "upper", "lower", "left" and "right" are used hereinafter to denote only the directions corresponding to the upper, lower, left, and right directions of the drawings, and do not limit the structure.
Referring to fig. 1, fig. 2 and fig. 3, fig. 1 is a schematic structural diagram of a combined overhead working platform scissor-fork type lifting limiting mechanism provided by the invention during installation; FIG. 2 is a schematic working diagram of a first limit switch and a first cam mechanism when a scissor fork of a combined overhead working platform scissor fork type limit mechanism provided by the invention rises; fig. 3 is a schematic working diagram of the second limit switch and the second cam mechanism when the scissor fork of the combined scissor fork type lifting limit mechanism of the aerial work platform provided by the invention descends.
The invention provides a combined scissor type lifting limiting mechanism of an aerial work platform, which comprises a first connecting shaft 14 penetrating between scissor forks and adjacent to a chassis, and a connecting rod 4 arranged in the middle of the scissor forks, wherein one end of the connecting rod is connected with the first connecting shaft 15, and the other end of the connecting rod is connected with the second connecting shaft 15 pivoted with the chassis through a pin joint, and the lifting limiting mechanism also comprises a limiting device and an angle sensor 12.
The limiting device comprises a first limiting switch 3 and a first cam mechanism 2 which are fixedly arranged on one side of the connecting rod 4, and the first cam mechanism 2 is fixedly arranged on the side face of the connecting rod 4 through a set screw 5. The limiting device further comprises a second limiting switch 7 and a second cam mechanism 6 which are fixedly arranged on the other side of the connecting rod 4, and the second cam mechanism 6 is fixedly arranged on the other side face of the connecting rod 4 through a set screw 1.
The first cam mechanism 2 penetrates the connecting shaft 14 and its boss is disposed toward the second connecting shaft 15. The second cam mechanism 6 penetrates the first connecting shaft 14 and has a boss disposed at a position which is rotated clockwise (clockwise as shown in fig. 3) by 60 degrees from the line connecting the first connecting shaft 14 and the second connecting shaft 15.
The first limit switch 3 is fixedly arranged on the side surface of the connecting rod 4, and the roller of the first limit switch is abutted against the first cam mechanism 2; the second limit switch 7 is fixedly arranged on the side surface of the connecting rod 4, and the roller of the second limit switch is abutted against the second cam mechanism 6. The first limit switch 3 and the second limit switch 7 are all in the prior art, and can be implemented by a person skilled in the art, and are not described herein.
The bosses of the first cam mechanism 2 and the second cam mechanism 6 are smaller than the minimum outer diameter, and a smooth curved surface is arranged on the bosses for rolling the rollers of the first limit switch 3 or the second limit switch 7.
The second connecting shaft penetrates through a first support 13 on the chassis, the angle sensor 12 comprises a fixing piece and a movable piece which extends along the fixing piece and can rotate, and the fixing piece is located on an axis extension line of the second connecting shaft 15 and is arranged on the outer side of the first support 13. The movable piece is connected with a second support 11, and the other end of the second support 11 is fixed with the side face of the connecting rod 4 through a bolt 8, a gasket 9 and a nut 10.
The section of the second support 11 is in a zigzag structure, and the installation direction of the second support is the same as the length extension direction of the connecting rod 4.
In the present embodiment, the angle sensor 12 is provided adjacent to the first limit switch 3 and the first cam 2 side.
The angle sensor 12 is used for monitoring the whole process of the ascending or descending state of the scissors.
The invention also provides a working method of the combined overhead working platform scissor fork type lifting limiting mechanism, which comprises the following steps:
as shown in fig. 2, when the scissors are raised:
s1, an operator presses a lifting button, and a hydraulic system pressurizes a hydraulic lifting oil cylinder, so that the stroke of the lifting oil cylinder is increased and the scissor fork is driven to lift.
S2, lifting the scissors to enable the first connecting shaft 14, the second connecting shaft 15 and the connecting rod 4 to move relatively;
s3, the first connecting shaft 14 rotates anticlockwise relative to the connecting rod 4, when the boss of the first cam mechanism 2 touches the roller of the first limit switch 3, the roller of the first limit switch 3 is pressed down, and the first limit switch 3 starts to work.
S4, the lifting oil cylinder of the aerial working platform normally works until the lifting oil cylinder approaches to the maximum stroke, the boss of the first cam mechanism 2 is separated from the first limit switch 3, the roller of the first limit switch 3 is restored to a natural state, the first limit switch 3 stops working, and the hydraulic system of the aerial working platform stops supplying oil to the lifting oil cylinder.
When the scissors are lowered:
s1, an operator presses a descending button, and a hydraulic system releases pressure to a hydraulic lifting oil cylinder, so that the stroke of the lifting oil cylinder is reduced and a scissor fork is driven to descend;
s2, when the scissors are descended, the first connecting shaft 14, the second connecting shaft 15 and the connecting rod 4 are moved relatively.
S3, the first connecting shaft 14 rotates clockwise relative to the connecting rod 4, when a boss of the second cam structure 6 touches a roller of the second limit switch 7, the roller of the second limit switch 7 is pressed down, and the second limit switch 7 starts to work;
s4, stopping releasing the pressure by the lifting oil cylinder, and stopping descending.
The descending process in the step S4 is segmented descending, and the pressure is released continuously after the descending in the first stage is stopped for a plurality of seconds until the scissors are descended to a natural state.
The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, and all equivalent structures or equivalent processes or direct or indirect application in other related technical fields are included in the scope of the present invention.