Testing apparatus and respective control circuit

Claim 3

The apparatus according to claim 1, wherein said first and second load applying means comprise respective piston cylinder means including piston rods arranged to be effective substantially at right angles relative to each other and on a common force application point of said sample.

Claim 4

The apparatus according to claim 2, further comprising lever means journaled to said sample, said lever means having an effective length substantially corresponding to the diameter of a wheel carried by an axle, and means for Connecting said piston rods to said lever means at a point corresponding to a point of contact between said wheel and the road.

Claim 5

The apparatus according to claim 1, comprising means providing rated values representing rated displacements and rated forces wherein one of said control value input means comprise input terminal means for receiving rates values representing a rated displacement of the respective load applying means and further input terminal means for receiving rated values representing a rated force to be applied by the respective load applying means.

Claim 6

The apparatus according to claim 1, wherein said one of said control value input means comprise transducer means arranged to sensing the displacement of the respective load applying means to provide actual displacement representing values of the respective load applying means, sensing means for ascertaining actual force representing values of the respective load applying means, and means applying said actual displacement representing values and actual force representing means to the respective control means.

Claim 7

The apparatus according to claim 1 for testing a motor vehicle axle, wherein said first load applying means comprises a first hydraulic piston cylinder means including a respective load applying piston rod which is effective vertically to simulate road shocks, said second load applying means comprises a second hydraulic piston cylinder means including a second load applying piston rod which is effective substantially horizontally and in a direction extending substantially in parallel to said axle to apply lateral forces, and a third hydraulic piston cylinder means including a third piston rod which is effective substantially horizontally and substantially perpendicularly relative to said first and second piston rod to apply acceleration forces and braking forces, said control value input means comprising a rated force input terminal and a rated displacement input terminal as well as displacement sensing means and force sensing means for said control means, a force differentiating and integrating circuit means having three inputs and an output, a displacement differentiating and integrating circuit means also having three inputs and an output, first switching means for alternately connecting one of said three inputs of the displacement differentiating and integrating circuit means to said first mentioned output and to said rated displacement input terminal, said output terminal means of said function generator means comprising a plurality of output terminals, second switching means for alternately connecting another of said inputs of the displacement differentiating and integrating circuit means to different ones of said output terminals of said function generator means, means for connecting the third input of the displacement differentiating and integrating means to said displacement sensing means, means for connecting said force sensing means to one of the inputs of said force differentiating and integrating circuit means, means for connecting said rated force input terminal to another of said inputs of the force differentiating and integrating circuit means, means for connecting the third input terminal of said force differentiating and integrating circuit means to one of said output terminals of said function generator means, braking signal input means, means for connecting said braking signal input means to said first and second switching means for controlling said first and second switching means in response to the application of a braking signal, and means for connecting said control means of the third hydraulic piston cylinder means to the output of said displacement differentiating and integrating circuit means whereby said third hydraulic piston cylinder means is displacement controlled when said first and second switching means are in one position and whereby said third hydraulic piston cylinder means is force controlled when said first and second switching means are in another position in reSponse to the presence of a braking signal at the braking signal input means.

Claim 8

The apparatus according to claim 6, wherein said piston rods are effective on a common load application point spaced from said axle, means for connecting said common load application point to said axle, said third piston rod which applies acceleration and braking forces to said common point, maintaining said point vertically below said axle in response to a rated displacement value applied to said rated displacement input terminal whereby said third piston cylinder means is controlled in response to displacement.

Claim 9

The apparatus according to claim 7, comprising further differentiating and integrating circuit means also including a respective plurality of inputs and an output connected to one input of said first mentioned differentiating and integrating circuit means, said function generator means comprising means for computing force correction values from said rated and actual displacement representing values as a function of the geometric dimensions of said sample, means for supplying said force correction values from respective ones of said plurality of said function generator output terminals to respective inputs of said further differentiating and integrating circuit means, and means for also supplying said rated and actual displacement representing values to respective ones of said further differentiating and integrating circuit means.

Claim 10

The apparatus according to claim 6, wherein said piston rods are effective on a common load application point spaced from said axle, means for connecting said common load application point to said axle, said third piston rod which applies acceleration and braking forces to said common point maintaining said point spaced from the vertical extending through said axle and below said axle in response to a force value applied to said force differentiating and integrating circuit means, whereby said third piston cylinder means is force controlled.

Claim 11

The apparatus according to claim 1, wherein said control means comprise differentiating and integrating circuit means including a plurality of inputs and an output as well as a control member for the respective load applying means, means for connecting said output to said control member, said control value input means comprising a rated displacement input terminal and actual displacement sensing means, said input terminal means and output terminal means comprising a plurality of input terminals and a plurality of output terminals respectively, means for connecting said rated displacement input terminal and said actual displacement sensing means to respective ones of said plurality of inputs of the differentiating and integrating circuit means and to respective ones of said plurality of input terminals of said function generator means for computing a displacement correction value from rated and actual displacement representing values dependent on the geometric dimensions of said sample, and means for connecting one of said output terminals of said function generator means also to a respective input of said differentiating and integrating circuit means whereby said displacement correcting value is applied to said last mentioned input.

Claim 12

The apparatus according to claim 1, wherein loads are applied to at least two points of a test sample, said apparatus further comprising means operatively connected to said computer means for supplying to said function generator means displacement representing values for each of said two points, said function generator means comprising means for calculating correction values as a function of coupling factors representing the mutual influence between said two load application points and in response to said displacement representing values.

Claim 13

The apparatus according to claim 1, comprising brake means coupled to said sample, means for actuating said brake means wherein said function generator means comprise storage means for storing displacement values in response To the actuation of said brake means, and means for calculating correction values as a function of displacement curves of said load application point whereby said curves are determined by said stored displacement values.

Claim 14

The apparatus according to claim 1, wherein said sample is a vehicle axle, said apparatus further comprising lever means, and means for operatively connecting one end of said lever means to said axle while the other end of said lever means constitutes said load application point whereby torque moments may be applied to said axle through said lever means.

Claim 15

The apparatus according to claim 13, wherein said connecting means comprise means for rotatably securing one end of said lever means to said axle whereby the lever is rotatable about said axle.

Claim 16

The apparatus according to claim 13, wherein said connecting means comprise means for blocking rotation between said lever and said axle.