CN203178143U - Automatic bending rigidity test device - Google Patents

Abstract

The utility model relates to an automatic bending rigidity test device. A CCD (charge coupled device) is used for collecting a light spot image, the displacement of a light spot is measured by utilizing a computer image processing algorithm, a bending deformation turning angle is obtained, the force is measured through a pulling force sensor, a loaded torque is obtained, and the bending rigidity can be calculated through a computer. The automatic bending rigidity test device is simple and convenient to operate and suitable for automatically and efficiently measuring the bending rigidity.

Description

The automatic testing equipment of bending stiffness

Technical field:

The utility model relates to a kind of device for testing stiffness, specifically a kind of automatic testing equipment of bending stiffness.

Background technology:

The bending stiffness test all is widely used in industries such as vehicle, lathe, hoisting devices.Patent 200910264011.X discloses a kind of method for detecting static rigidity of light passenger car body, this method adopts counterweight or lever to load, the displacement sensor torsion angle can produce certain load fluctuation because counterweight loads, and it is bigger to calculate angular errors by displacement.

The utility model content:

The purpose of this utility model is to provide at the deficiencies in the prior art a kind of automatic testing equipment of bending stiffness.This device adopts CCD and computing machine to load measurement, the measuring accuracy height, and the automaticity height, easy and simple to handle.

The technical solution of the utility model: a kind of automatic testing equipment of bending stiffness, measured piece is fixed on the testing machine table top, couple loading frame upper end connects the testing machine loading head, the lower end is connected with measured piece top, laser tube emission laser is to measured piece measuring point catoptron, and reflected light forms luminous point at screen, and CCD looks like to import into computing machine with dot pattern, pulling force sensor in the couple loading frame imports pulling force into computing machine, is obtained the bending stiffness of measured piece by Computer Processing.

Described couple loads by testing machine and produces, and laser spots incides on the measured object front-surface mirror, and CCD gathers the dot pattern picture, and computing machine looks like to handle to dot pattern measures crooked corner, and pulling force sensor is gathered loading force, and computing machine is handled bending stiffness automatically.

The beneficial effects of the utility model are: compared with the prior art, the utility model is a kind of automatic testing equipment of the bending stiffness based on testing machine and CCD, the measuring accuracy height, and the automaticity height, easy and simple to handle.

Description of drawings:

Fig. 1 is structural representation of the present utility model.

Fig. 2 is the crooked corner test philosophy of measuring point figure.

Mark among the figure: 1 measured piece, 2 couple loading frames, 3 testing machines, 4 pulling force sensors, 5 laser tubes, 6 screens, 7CCD, 8 computing machines.

Embodiment:

As shown in Figure 1, the automatic testing equipment of bending stiffness.Comprise 1 measured piece, 2 couple loading frames, 3 testing machines, 4 pulling force sensors, 5 laser tubes, 6 screens, 7CCD, 8 computing machines.

Described measured piece 1 bottom is fixed on testing machine 3 table tops with pressing plate, and measured piece 1 top is connected with couple loading frame 2, and couple loading frame 2 is connected with the loading head of testing machine 3.

Described couple loading frame 2 is made up of horizon bar, wire rope and three fixed pulleys, and when testing machine 3 loading heads moved up, 2 pairs of measured pieces of couple loading frame 1 produced the pure bending force couple role.

Stick catoptron (3 measuring points are arranged among Fig. 1) at the selected measuring point place of measured piece 1, laser tube 5 incides each measuring point place respectively, by mirror reflects to screen 6 at a distance.CCD7 gathers screen 6 glazing dot image, imports computing machine 8 into and carries out the image processing.

Computing machine 8 calculates the luminous point coordinate, obtains spot displacement, and pulling force sensor 4 imports load into computing machine 8, can gather diastrophic moment and corner simultaneously and calculate bending stiffness, and the result is presented on the computer screen, and is kept in the data file.

Measuring principle is as follows:

As shown in Figure 2, establish load before laser incide measuring point place catoptron back reflection A point to the screen, load back reflection light and move to B point on the screen, A, B two spot distance are d, measuring point is S to screen distance, then the corner b of measuring point place has computing formula: b=d/ (2*S).

Wherein spot distance d is obtained by image processing program.Adopt the grey scale centre of gravity formula:

$X_C=\frac{{\mathrm{\Σ}}_{i_0}^{i_i}{\mathrm{\Σ}}_{j_0}^{j_f}j(T-f_{\mathrm{ij}})}{{\mathrm{\Σ}}_{i_0}^{i_f}{\mathrm{\Σ}}_{j_0}^{j_f}(T-f_{\mathrm{ij}})}$

$y_C=\frac{{\mathrm{\Σ}}_{i_0}^{i_i}{\mathrm{\Σ}}_{j_0}^{j_f}i(T-f_{\mathrm{ij}})}{{\mathrm{\Σ}}_{i_0}^{i_f}{\mathrm{\Σ}}_{j_0}^{j_f}(T-f_{\mathrm{ij}})}$

In the formula T be dot pattern as gray threshold, f is each gray values of pixel points, x and y are luminous point gray scale centre coordinates.The difference of two luminous point grey scale centre of gravity coordinates is spacing d.

The spot distance precision is 0.1 millimeter in the image processing system, and measuring point is 5 meters to screen distance, and then measuring point place outer corner measurement precision is 0.1/ (2*5000), i.e. 0.00001 radian.

If it is M that testing machine loads moment of flexure, measuring point place corner is b, and then bending stiffness is K=M/b.

Claims (2)

1. the automatic testing equipment of a bending stiffness, it is characterized in that: measured piece (1) is fixed on testing machine (3) table top, couple loading frame (2) upper end connects testing machine (3) loading head, the lower end is connected with measured piece (1) top, laser tube (5) emission laser is to measured piece measuring point catoptron, reflected light forms luminous point at screen (6), CCD (7) looks like to import into computing machine (8) with dot pattern, pulling force sensor (4) in the couple loading frame (2) imports pulling force into computing machine (8), is handled the bending stiffness that obtains measured piece (1) by computing machine (8).

2. the automatic testing equipment of a kind of bending stiffness according to claim 1, it is characterized in that: couple loading frame (2) is made up of horizon bar, wire rope and three fixed pulleys, when testing machine (3) when loading head moves up, couple loading frame (2) produces the pure bending force couple role to measured piece (1).

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