A reproduction of a lift test device

Abstract

The application provides a recurrent lift and sink test device and belongs to the technical field of mechanical control. The existing device can realize a working condition with a large load mass, a large recurrent acceleration and a long stroke, and a guide rail needs to bear a large lateral force, especially when the stroke is large, the lateral force can cause large deformation of the guide rail. The device comprises a lifting actuator assembly, a cross beam assembly, a moving platform, a stand, a base and a torque balance assembly, four corners of the lower end surface of the cross beam assembly are provided with the stand, the bottom of the stand is connected with the base, the moving platform is slidingly installed on the stand, four lifting actuator assemblies penetrate through the cross beam assembly and are connected with the moving platform, the torque balance assembly is installed at the connection position of the moving platform and the stand, and the cross beam assembly is provided with an accumulator assembly for supplying energy to the lifting actuator assembly. The device is mainly used for testing the working condition with a large load mass, a large recurrent acceleration and a long stroke.

Description

Technical Field

[0001] This invention belongs to the field of mechanical control technology, and in particular relates to a device for reproducing lifting tests. Background Technology

[0002] For vertical reciprocating motion, the traditional design method uses several vertical guide rails to meet the test requirements. Vertical supports are designed, each with a set of guide rails, and the test is driven by hydraulic actuators. For conditions involving large loads, high reproducible accelerations, and long strokes, the guide rails must withstand significant lateral forces, especially during long strokes, which can cause substantial deformation. Furthermore, to balance the overturning force of the entire system, the guide rail mechanism needs to exhibit minimal thermal deformation under prolonged testing. Additionally, if multiple guide rail systems perform unified vertical motion, inconsistent motion characteristics among the rails can generate significant internal forces, further exacerbating heat generation and deformation. Summary of the Invention

[0003] In view of this, the present invention aims to propose a reproducible lifting test device to solve the problem that existing equipment, when performing tests on conditions with large load mass, large reproducible acceleration, and long stroke, requires the guide rail to withstand a large lateral force, especially when the stroke is large, the lateral force will cause large deformation of the guide rail.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A reproducible lifting test device includes a lifting actuator assembly, a crossbeam assembly, a motion platform, columns, a base, and a torque balancing assembly. Columns are installed at the four corners of the lower end face of the crossbeam assembly, and the bottom of each column is connected to the base. The motion platform is slidably mounted on the columns. Four lifting actuator assemblies pass through the crossbeam assembly and are connected to the motion platform. A torque balancing assembly is installed at the connection between the motion platform and the columns.

[0006] Furthermore, the beam assembly is equipped with an energy storage assembly for powering the lifting actuator assembly.

[0007] Furthermore, the bottom of the base is connected to a pre-embedded tie rod.

[0008] Furthermore, the base is shaped like a star.

[0009] Furthermore, the column has a box structure, and guide plates are installed on two parallel sides of the column.

[0010] Furthermore, the torque balancing assembly includes a torque cylinder and an oil film disc, the oil film disc being mounted on the front end of the piston rod of the torque cylinder, and the torque cylinder being connected to the column.

[0011] Furthermore, the oil film disc is connected to the plunger rod via a ball joint.

[0012] Furthermore, a disc spring is installed on the outside of the torque cylinder.

[0013] Furthermore, a piping assembly is installed on the column.

[0014] Furthermore, the lifting actuator assembly is controlled using a statically indeterminate degree-of-freedom control method.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] The base of this invention is connected to the pre-embedded foundation components poured in the foundation pit. The entire device frame is supported by four columns. Each column serves as both the motion base of the torque balancing component and the vertical support of the crossbeam component. Simultaneously, the oil supply to the crossbeam component is delivered through pipeline components on each column. The upper surface of the motion platform is fixed to heavy loads via mounting holes. The motion platform moves up and down on the columns via torque balancing components attached to the four corner supports. The up-and-down movement of the motion platform is achieved by lifting actuator components inverted and fixed to a pair of frames of the crossbeam. Peak pipeline flow is supplemented by an accumulator component fixed to another pair of frames of the crossbeam. The motion platform employs a statically indeterminate degree-of-freedom control strategy to control three degrees of freedom to achieve the up-and-down movement of the motion platform, avoiding overturning moments, ensuring the flatness of the motion platform, and preventing multiple guide rails from completing uniform vertical movement. If the motion characteristics of each guide rail are inconsistent, large internal forces will be generated, further exacerbating the problems of guide rail heating and deformation. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 This is a schematic diagram of the structure of a reproducible lifting test device according to the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the base described in this invention;

[0020] Figure 3 This is a stress diagram of the column described in this invention;

[0021] Figure 4 This is a schematic diagram of the structure of the motion platform described in this invention;

[0022] Figure 5 This is a stress diagram of the motion platform described in this invention;

[0023] Figure 6 This is a schematic diagram of the torque balancing assembly described in this invention. Figure 1 ;

[0024] Figure 7 This is a schematic diagram of the torque balancing assembly described in this invention. Figure 2 ;

[0025] Figure 8 For the degree of freedom control strategy Figure 1 ;

[0026] Figure 9 For the degree of freedom control strategy Figure 2 .

[0027] 1-Lifting actuator assembly, 2-Accumulator assembly, 3-Crossbeam assembly, 4-Motion platform, 5-Column, 6-Base, 7-Pipeline assembly, 8-Torque balance assembly, 9-Oil film disc, 10-Torque cylinder, 11-Spherical hinge, 12-Disc spring. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0029] See Figure 1-9 This embodiment describes a reproducible lifting test device, comprising a lifting actuator assembly 1, a crossbeam assembly 3, a motion platform 4, a column 5, a base 6, and a torque balancing assembly 8. Columns 5 are installed at the four corners of the lower end face of the crossbeam assembly 3, and the bottom of each column 5 is connected to the base 6. The motion platform 4 is slidably mounted on the columns 5. Four lifting actuator assemblies 1 penetrate the crossbeam assembly 3 and are connected to the motion platform 4. A torque balancing assembly 8 is installed at the connection between the motion platform 4 and the columns 5. The bottom of the base 6 is connected to a pre-embedded tie rod. A pipeline assembly 7 is installed on the columns 5.

[0030] The entire device is installed on the base 6, which is connected to the foundation embedded parts that have been poured in the foundation pit in advance. The entire device frame is supported by four columns 5. Each column 5 serves as the moving base surface of the torque balancing component 8 on one hand, and as the vertical support of the crossbeam component 3 on the other hand. At the same time, the oil supply on the crossbeam component 3 is delivered through the pipeline component 7 on each column 5. The upper surface of the motion platform 4 is fixed with heavy loads through mounting holes. The motion platform 4 moves up and down on the columns 5 by the torque balancing components 8 attached to the four corner brackets.

[0031] Furthermore, a maintenance platform is installed on the outside of the crossbeam assembly 3, the base 6 serves as the installation foundation for the entire frame, the column 5 is the supporting foundation for the crossbeam assembly 3 and plays a guiding role for the motion platform 4, and the crossbeam assembly 3 is the installation foundation for the lifting actuator assembly 1 and also the connecting body for the column 5.

[0032] Furthermore, an energy storage assembly 2 for supplying power to the lifting actuator assembly 1 is installed on the crossbeam assembly 3. The up-and-down movement of the motion platform 4 is achieved by the lifting actuator assembly 1, which is inverted and fixed to a pair of side frames of the crossbeam assembly 3. The peak pipeline flow is supplemented by the energy storage assembly 2.

[0033] Furthermore, the base 6 is shaped like a star. The base 6 is an important component of the test equipment and serves as the overall installation foundation for the equipment. It is necessary to ensure the flatness and parallelism of the mounting surfaces of the four columns 5, as well as the relative dimensional accuracy of the mounting surfaces. It has mounting holes for connecting with the pre-embedded tie rods in the foundation. The base 6 adopts a welded structure. The star-shaped structure ensures the required rigidity while also ensuring a smaller mass. The base 6 is pre-drilled with grouting holes for secondary grouting with the foundation.

[0034] Furthermore, the column 5 is a box structure, and guide plates are installed on two parallel sides of the column 5.

[0035] The uprights 5 are installed at the four corners of the base 6. They are welded from steel plates and have a box-like structure with sufficient rigidity and strength. Planes are milled on two parallel sides of the uprights 5, and guide plates are installed thereon. These guide plates work in conjunction with the torque cylinders installed at the four corners of the moving platform 4, forming a balancing torque. The guide plates guide the lifting and lowering motion of the moving platform and the load 4, and overcome the overturning moment generated when the system is out of control. A flange plate is welded to the bottom of the uprights 5, connecting it to the base 6. A bracket is welded to the top, serving as support for and connecting to the crossbeam assembly 3. The design of the uprights 5 specifically considers the pressure from the torque cylinder 10 in the event of a single-sided hydraulic cylinder failure, which would generate an overturning moment. To verify the strength of the contact surface between the uprights 5 and the torque balancing assembly 8, the uprights 5 are analyzed as a single unit. The mounting surfaces of the uprights and the base 6 are fixedly constrained. The maximum and minimum forces of the torque cylinder 20, i.e., the maximum output force of the torque cylinder when the system is out of control, are applied to the contact surface between the oil film plate 9 and the guide plate of the uprights 5.

[0036] The crossbeam assembly 3 is welded from steel plates and has a box-like structure. One type of crossbeam has two sets of cylinders arranged in the middle to hold the upper ball joint of the lifting actuator assembly 1. The crossbeam assembly 3 has sufficient rigidity and strength and is installed on the brackets above the four columns 5 to connect the four columns into one unit. The crossbeam assembly 3 is used to install the lifting actuator assembly 1 and the accumulator assembly 12 and improve the stability of the entire mechanical frame.

[0037] Furthermore, the torque balancing assembly 8 includes a torque cylinder 10 and an oil film disc 9. The oil film disc 9 is installed at the front end of the piston rod of the torque cylinder 10, and the torque cylinder 10 is connected to the column 5.

[0038] The motion platform 4 is a crucial component, serving as the mounting base for the test specimen and the torque cylinder 10 in the torque balancing assembly 8. It must possess sufficient rigidity and natural frequency, along with minimal mass. The rigidity and strength of the mounting surfaces for the 16 torque cylinders 12 must be guaranteed, and the flatness and relative dimensional accuracy of the mounting surfaces must be considered. The motion platform 4 has mounting flanges on both sides for connection to the lower hinge of the lifting actuator 1. The central area is used for mounting the test specimen. The motion platform 4 is integrally welded, and its mesh structure ensures both the required rigidity and minimal mass. The four corner supports of the motion platform 4 cooperate with the torque cylinders 10 and the columns 5 to form a structure that resists overturning moments.

[0039] The oil film disc 9 is connected to the plunger rod via a ball joint 11.

[0040] A disc spring 12 is installed on the outside of the torque cylinder 10.

[0041] The torque balancing assembly 8 includes a torque cylinder 10, a ball joint 11, and an oil film disc 9 mounted on the four corner supports of the platform. The guide plate on the surface of the column 5 and the oil film disc mounted on the front end of the piston rod of the torque cylinder 10 provide guidance for the reciprocating motion of the motion platform 3. At the same time, the adaptive disc spring of the torque cylinder 10 can overcome the defects caused by the large system stroke, high speed and inconsistent clearance of the guide device, and balance the overturning moment generated when the system is out of control. The piston rod of the torque cylinder 10 and the spherical bearing seat of the ball joint are designed as an integral part. The front end of the piston rod has a spherical cavity in the middle, which tightly wraps the ball joint 11. When the platform rotates at a small angle, the ball joint swings while the torque cylinder is stationary, ensuring that the oil film disc 9 is in parallel contact with the plane of the guide plate, thereby supporting the load-bearing platform.

[0042] The lifting actuator assembly 1 is controlled using a statically indeterminate degree-of-freedom control method.

[0043] To prevent the platform from generating overturning moments, and to reduce internal forces during the vertical lifting process of the four lifting actuators 1, a statically indeterminate degree-of-freedom control strategy is proposed to control three degrees of freedom, rather than the traditional approach of controlling only the vertical degree of freedom. Figure 8As shown, the three degrees of freedom controlled here are translation along the Z-axis, rotation around the X-axis, and rotation around the Y-axis. The translation command is the given control command, while the commands for rotation around the X and Y axes are zero. This ensures that the angles around the X and Y axes are not excessively large, resulting in a smaller overturning moment. The control structure employs a degree-of-freedom synthesis module and a degree-of-freedom decomposition module. The degree-of-freedom synthesis module converts the displacements of the four lifting actuators into three degrees of freedom values, while the degree-of-freedom decomposition module decomposes the drive command adjusted by the controller into excitation values ​​for the four lifting actuators, thereby controlling the actuator motion. The degree-of-freedom synthesis module D and the degree-of-freedom decomposition module C are shown below.

[0044]

[0045] This avoids the overturning moment generated by the motion platform 4, ensures the flatness of the motion platform 4, and prevents multiple guide rails from completing uniform vertical movement. If the motion characteristics of each guide rail are inconsistent, a large internal force will be generated, which will further aggravate the problems of heat generation and deformation of the guide rails.

[0046] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A reproducible lift-off test apparatus, characterized by: It includes lifting actuator assembly (1), beam assembly (3), motion platform (4), column (5), base (6) and torque balance assembly (8), the lower end surface of the beam assembly (4) is installed at four corners, the bottom of the column (5) is connected with the base (6), the motion platform (4) is slidingly installed on the column (5), four lifting actuator assemblies (1) are connected with the motion platform (4) through the beam assembly (3), the motion platform (4) is installed with torque balance assembly (8) at the connection with the column (5), the torque balance assembly (8) includes torque cylinder (10) and oil film disc (9), the oil film disc (9) is installed at the front end of the plunger rod of the torque cylinder (10), the torque cylinder (10) is connected with the column (5), the oil film disc (9) is connected with the plunger rod through ball hinge (11), the torque cylinder (10) is installed with disc spring (12) outside, the oil film disc (9) provides guidance for the reciprocating motion of the motion platform (3), at the same time, the self-adaptive disc spring of the torque cylinder (10) automatically expands and contracts to balance the overturning moment generated when the system loses control, the plunger rod of the torque cylinder (10) is integrally designed with the spherical bearing seat of the ball hinge, the front end of the plunger rod is a spherical cavity, tightly wrapping the ball hinge (11), when the platform is overturned by a small angle, the ball hinge swings under the condition that the torque cylinder does not move, ensuring that the oil film disc (9) and the guide plate plane are in parallel contact, thereby supporting the bearing platform.

2. A reproducible lifting test device according to claim 1, characterized in that The beam assembly (3) is installed with accumulator assembly (2) for supplying energy to the lifting actuator assembly (1).

3. A reproducible lift-off test device according to claim 1, characterized in that: The bottom of the base (6) is connected with a pre-buried pull rod.

4. A reproducible lift-off test apparatus according to claim 1, wherein: The base (6) is in the shape of a rice character.

5. A reproducible lift-off test apparatus according to claim 1, wherein: The column (5) is in the form of a box body, and the two parallel sides of the column (5) are installed with guide plates.

6. A reproducible lift-off test apparatus according to claim 1, wherein: The column (5) is installed with pipeline assembly (7).

7. A reproducible lift-off test apparatus according to claim 1, wherein: The lifting actuator assembly (1) is controlled by using the superstatic degree of freedom control method.

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