CN203178145U - Automatic tester for torsional rigidity - Google Patents

Abstract

The utility model discloses an automatic tester for torsional rigidity. An image of a light spot is collected by a CCD (charge coupled device); the displacement of the light spot is measured by a computer according to an image processing algorithm, so as to obtain a torsional deformation angle; the force is measured by a tension sensor; and a loaded moment is obtained, so as to calculate the torsional rigidity. The automatic tester is simple and convenient to operate, and suitable for automatic measurement of high-accuracy torsional rigidity.

Description

The automatic testing equipment of torsional rigidity

Technical field:

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

Background technology:

The torsional rigidity test all is widely used in industries such as vehicle, lathe, space flight.Patent 200810171539.8 discloses a kind of bush torsional rigidity measurement method for automotive suspension, and this method adopts bearing circle to load, and angular transducer is measured torsion angle, can produce certain load fluctuation because bearing circle loads, and the angular transducer error is bigger.

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 torsional rigidity.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 torsional rigidity, 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 torsional rigidity 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 measurement to dot pattern and reverses corner, and pulling force sensor is gathered loading force, and computing machine is handled torsional rigidity 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 torsional rigidity 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 that measuring point reverses corner test philosophy 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 torsional rigidity.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 four fixed pulleys, and when testing machine 3 loading heads moved up, 2 pairs of measured pieces of couple loading frame 1 produced pure torsional couple effect.

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 moment and the corner of torsional deflection simultaneously and calculate torsional rigidity, 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 torsional moment, measuring point place corner is b, and then torsional rigidity is K=M/b.

Claims (2)

1. the automatic testing equipment of a torsional rigidity, 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 torsional rigidity that obtains measured piece (1) by computing machine (8).

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

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