CN104034478B - The support arrangement that in centroid measurement, ball-and-socket, needling, plane combine - Google Patents

Abstract

A support device that combines ball sockets, column sockets, and planes in centroid measurement involves a support structure to solve the problem that the sensor is difficult to automatically adjust to the center of the bearing point in the existing ball-ball socket support method for centroid measurement. The centering position accuracy is poor and the ball plane support method has the problem of large guiding friction, which includes a ball socket support structure, a ball plane support structure and a measuring platform; the support device also includes a column socket support structure; the column socket support structure Including column nest plate, steel ball, ball seat, load-bearing sensor, load-bearing sensor tray and base, load-bearing sensor is installed on the load-bearing sensor tray, the load-bearing sensor tray is rotated and installed on the base, the base is installed on the measuring pedestal, and the ball seat is detachable and installed On the load-bearing sensor, a steel ball is placed in the middle of the upper surface of the ball seat, and a horizontally arranged column socket plate is placed on the upper part of the steel ball. The invention is used for the measurement of the centroid of large-scale aircraft.

Description

Supporting device combining ball socket, column socket and plane in centroid measurement

technical field

The invention relates to a support structure, in particular to a support structure of large-scale aircraft centroid measurement equipment.

Background technique

The support method of large-scale aircraft centroid measurement equipment and the problem of lateral force have always existed, which affect the measurement accuracy. From the basic principle of the multi-point method, it can be known that the output value of the sensor and the measurement value of the position of the force point of the sensor directly affect the measurement result of the mass center of mass, so how to ensure the accuracy of the output value of the sensor and the measurement value of the position of the force point of the sensor center has become an important issue for improvement. The key factor for the measurement accuracy of the centroid of mass measuring platform. The supporting structure of the sensor is a key factor affecting the output characteristics of the sensor and the position of the force point of the sensor.

At present, the impact of the sensor support method on the centroid measurement results,

The main factors that affect the accuracy of the sensor output value for the mass centroid measuring platform are:

□The sensor data acquisition module is subject to electrical interference, resulting in unstable data acquisition;

□Unreasonable software data processing affects measurement accuracy;

□ The bearing point of the measuring bracket is not aligned with the force point of the sensor center, and there is a lateral force, which leads to deviations in the measurement results.

The main reasons that affect the measurement accuracy of the sensor force point position are:

□ Coordinate measurement equipment accuracy limit;

□ There are human error in the measurement process;

□The bearing point of the measuring bracket is not on the same vertical line as the stress point of the sensor center, and the measured coordinates of the bearing point in the horizontal axis X and vertical axis Y directions are not in the horizontal axis X and vertical axis Y directions of the sensor center force point coordinate of.

It can be seen from the above analysis that the factors that affect the accuracy mainly include measuring instruments, software, electromagnetic interference, and sensor support mechanisms. The accuracy problem of the instrument can be solved by replacing the high-precision instrument, the software processing problem can be improved by modifying the program, and the electromagnetic interference can be solved by the shielding device. If there is a misalignment problem, it is difficult to solve. Because the mechanical structure of the mass center of mass measuring platform is large in size, high in cost, and long in processing cycle, it is difficult to modify it after assembly. Therefore, the mechanical structure design principle of the sensor support structure must be strictly demonstrated and accurately calculated according to the measurement requirements before machining. The distribution position and machining size of the sensor support structure should be as far as possible to ensure that it is on a vertical line with the center point of the sensor to reduce measurement errors.

At present, ball-socket support method and ball-plane support method are the most widely used support methods for measuring brackets and sensors on the centroid measuring platform based on the multi-point method.

Ball-socket support method: The ball-socket support structure is shown in Figure 1-2, generally consists of sensor support structure (base, thrust ball bearing, bearing seat), sensor, pressure steel ball seat, steel ball and ball socket Composition, the size of the ball socket and the ball must meet a certain relationship, can move freely, and can be sensitively returned to the center, and a thrust ball bearing is placed at the bottom of the sensor to reduce the friction between the sensor and the base when it moves. When the steel ball produces a lateral force, the ball can drive the sensor to swim horizontally, thereby eliminating the lateral force and aligning the bearing point with the center of the sensor.

The mechanical structure of the ball-socket support structure is relatively simple, easy to realize, and the sensor is more flexible in centering, which can meet the general measurement requirements and is widely used. However, in the actual measurement process, due to the influence of some factors such as mechanical structure deformation, machining accuracy, and installation and leveling accuracy, it is not flexible for the three sensors to swim horizontally at the same time, and it is difficult for the sensors to automatically adjust to the center of the bearing point. In an ideal state, the centroid measurement device with high precision requirements still cannot meet the measurement requirements, and the improvement in accuracy is not obvious after improvement.

Ball-plane support method: The structure of the ball-plane support method is shown in Figure 3. It consists of a sensor support structure, a sensor, a steel ball seat and a steel ball. This support method must be used with a guide column, as shown in the figure. The sensor of the ball-plane support method is directly placed on the tray and the base, and is fixed on the base of the measuring table together, and cannot freely move horizontally during the measurement process. Since the contact part of the steel ball and the measuring bracket is a plane, the steel ball is not constrained, for To prevent the measuring bracket and the product to be measured from sideways, install a guide column on the lifting rod of the lifting mechanism to fix the position of the measuring bracket.

In the ball-plane support method, the steel ball is not affected by the lateral force of the upper ball socket, and the side sliding force of the steel ball is small, which makes it easier to achieve the centering of the bearing point and the force point of the sensor center. When the measuring bracket is sideways, although the guide column plays a positioning role, it also produces a lot of friction, which seriously affects the accuracy of the sensor's measurement value. This method is not used much in current measurements.

Contents of the invention

The present invention aims to solve the problems that the existing ball-socket support method for centroid measurement is difficult for the sensor to automatically adjust to the center of the bearing point, the accuracy of the centering position is poor, and the ball-plane support method has a large guide friction force, and then Provided is a support device combining ball sockets, column sockets and planes in centroid measurement.

The technical scheme adopted by the present invention for solving the above-mentioned problems is: the support device combining the ball socket, column socket and plane in the center of mass measurement of the present invention includes a ball socket support structure, a spherical plane support structure and a measuring pedestal; the support device also includes The column socket support structure, the ball socket support structure, the column socket support structure and the spherical plane support structure are arranged in an isosceles triangle on the measuring platform; the column socket support structure includes a column socket plate, steel balls, ball seats, load-bearing sensors, load-bearing The sensor tray and the base, the load-bearing sensor tray is installed with load-bearing sensors, the load-bearing sensor tray is rotated and installed on the base, the base is installed on the measuring platform, the ball seat is detachably installed on the load-bearing sensor, and the middle part of the upper surface of the ball seat is placed with steel The ball is placed on the upper part of the steel ball with a horizontally arranged column socket plate, and the lower surface of the column socket plate is processed with a groove with a semicircular arc in section along the length direction, and the steel ball leans against the groove.

The beneficial effects of the present invention are: the ball-socket and column-socket-plane support method adopts the three-point support method, and the three sensors are installed on the base according to an isosceles triangle, and the contact modes of each sensor and the measuring bracket are different, respectively. Three structures with different degrees of flexibility are adopted: plane, ball socket and column socket. The position of the sensor of the plane support structure does not need to be adjusted, and the free movement of the steel ball on the plane can be used to realize the automatic centering of the support point and the center of the sensor, and the centering process is fast; the ball-and-socket support structure improves the flexibility of the sensor's horizontal swimming characteristics The lateral force caused by the measuring bracket and the product to be tested can be overcome by the horizontal movement of the sensor; in order to solve the side slip problem of the measuring bracket caused by the ball-plane structure without increasing the friction of the system, a column socket structure is designed. The lateral force of the measuring platform is reduced; and the laser tracker is used to measure the bearing point coordinates of the three sensors, which greatly improves the measurement accuracy. The points of three different structures are automatically centered at the same time, the mutual constraints are reduced, the time of the centering process is shortened, and the accuracy of the centering is greatly improved.

The ideal state of the measurement is that when the measuring table falls on the steel ball, if the contact points of the three ball sockets and the steel ball and the force point of the sensor center are on the same vertical line, the measured value of the sensor and the position measurement of the bearing point Highest precision.

The three-dimensional diagram of the ball-socket-column-socket-plane support method structure is shown in Figure 6. The measured value of the sensor can be output and displayed through the acquisition module such as a weighing instrument. When measuring the position coordinates of the force point of the sensor center, the laser tracker is used to measure the pre-designed visible positioning point on the measuring platform, and then the coordinate conversion is used to calculate the sensor center position coordinates. , the above are the measurements of the prior art. The invention adopts the three-point support mode of free and no lateral force of ball socket, column socket and plane, which ensures the uniqueness and repeatability of the action point, and realizes automatic centering free and without lateral force.

Description of drawings

Fig. 1 is a schematic diagram of the three-dimensional structure of the ball-socket support structure in the background technology, Fig. 2 is an exploded view of Fig. 1, Fig. 3 is a schematic diagram of the three-dimensional structure of the ball-plane support structure in the background technology, and Fig. 4 is a ball-socket support The three-dimensional structural diagram of the structure, Fig. 5 is a schematic diagram of a measuring bracket capable of installing a column socket, a ball socket and a plane three-point support of a guide column, and Fig. 6 is a schematic diagram of a three-dimensional structure of the present invention.

detailed description

Specific embodiment 1: In conjunction with Fig. 4-Fig. 6, the support device combining ball socket, column socket and plane in the centroid measurement of this embodiment includes ball socket support structure 1, spherical plane support structure 2 and measurement platform 3; The support device also includes a column socket support structure 4, the ball socket support structure 1, the column socket support structure 4 and the spherical plane support structure 2 are arranged in an isosceles triangle on the measurement platform 3; the column socket support structure 4 includes a column socket plate 4-1, steel ball 4-2, ball seat 4-3, load-bearing sensor 4-4, load-bearing sensor tray 4-5 and base 4-7, load-bearing sensor 4-4 is installed on the load-bearing sensor tray 4-5, load-bearing The sensor tray 4-5 is rotated and installed on the base 4-7, the base 4-7 is installed on the measuring platform 3, the ball seat 4-3 is detachably installed on the load cell 4-4, and the upper surface of the ball seat 4-3 A steel ball 4-2 is placed in the middle, and a horizontally arranged column socket plate 4-1 is placed on the upper part of the steel ball 4-2. The lower surface of the column socket plate 4-1 is processed with a groove 4 with a semicircular arc in section along the length direction -6, the steel ball 4-2 leans against the groove 4-6.

In this embodiment, the ball socket support structure 1 is preferably used as the apex of an isosceles triangle, and the middle part of the upper surface of the ball seat in this embodiment is processed with a hemispherical groove for placing steel balls.

Embodiment 2: The measurement base 3 in this embodiment is a circular base. This setting meets the design requirements and the actual centroid measurement needs. Others are the same as in the first embodiment.

Embodiment 3: In conjunction with FIG. 6 , the measuring base 3 in this embodiment is a rectangular base. This setting meets the design requirements and the actual centroid measurement needs. Others are the same as in the first embodiment.

Specific Embodiment Four: In conjunction with Fig. 5, the support device described in this embodiment also includes a measuring bracket 5, the upper surface of the ball socket plate 1-1 of the ball socket support structure 1, and the surface of the flat plate 2-1 of the ball plane support structure 2. Both the upper surface and the upper surface of the column socket plate 4 - 1 of the column socket support structure 4 are connected with the measuring bracket 5 . Such setting can meet the needs of mass centroid measurement. Others are the same as the specific embodiment 1, 2 or 3.

Embodiment 5: As described in conjunction with FIG. 4 and FIG. 6 , the load-bearing sensor tray 4-5 of this embodiment is rotatably mounted on the base 4-7 through bearings. In this way, thrust ball bearings are preferred for bearings in this embodiment, and thrust ball bearings are placed at the bottom of the sensor tray, which greatly reduces the friction between the load-bearing sensor and the load-bearing sensor tray when it moves. Others are the same as in Embodiment 4.

Claims (5)

1. the support arrangement that in centroid measurement, ball-and-socket, needling, plane combine, it includes ball-and-socket supporting construction (1), ball plane supporting structure (2) and measures pedestal (3)；It is characterized in that: described support arrangement also includes needling supporting construction (4), ball-and-socket supporting construction (1), needling supporting construction (4) and ball plane supporting structure (2) are arranged in isosceles triangle in measurement pedestal (3)；Described needling supporting construction (4) includes needling plate (4-1), steel ball (4-2), ball seat (4-3), bearing sensor (4-4), bearing sensor pallet (4-5) and base (4-7), bearing sensor pallet (4-5) is provided with bearing sensor (4-4), bearing sensor pallet (4-5) is rotatably installed on base (4-7), base (4-7) is arranged in measurement pedestal (3), ball seat (4-3) is removably mounted in bearing sensor (4-4), the middle part of the upper surface of ball seat (4-3) is placed with steel ball (4-2), steel ball (4-2) top is placed with horizontally disposed needling plate (4-1), the lower surface of needling plate (4-1) processes the groove (4-6) that cross section is semicircular arc along its length, steel ball (4-2) acts against on groove (4-6)。

2. the support arrangement that in centroid measurement according to claim 1, ball-and-socket, needling, plane combine, it is characterised in that: described measurement pedestal (3) is circular table base。

3. the support arrangement that in centroid measurement according to claim 1, ball-and-socket, needling, plane combine, it is characterised in that: described measurement pedestal (3) is rectangle pedestal。

4. the support arrangement that in the centroid measurement according to claim 1,2 or 3, ball-and-socket, needling, plane combine, it is characterized in that: described support arrangement also includes measurement bracket (5), the upper surface of the needling plate (4-1) of the ball-and-socket plate (1-1) of ball-and-socket supporting construction (1), the flat board (2-1) of ball plane supporting structure (2) and needling supporting construction (4) is all connected with measurement bracket (5)。

5. the support arrangement that in centroid measurement according to claim 4, ball-and-socket, needling, plane combine, it is characterised in that: bearing sensor pallet (4-5) is rotatably installed on base (4-7) by bearing。