Hydraulic servo material tester

A material testing, hydraulic servo technology, used in measuring devices, analyzing materials, and testing material strength by applying stable tension/pressure, which can solve problems such as control instability and oscillation

CN1410752AInactive Publication Date: 2003-04-16SHIMADZU SEISAKUSHO CO LTD +2
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2003-04-16
Estimated Expiration
Not applicable · inactive patent

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Abstract

The present invention discloses an adjusting unit in a feedback loop for controlling a hydraulically operated-type load mechanism consists of two portions both adapted to effect proportional action and derivative action. Weights are applied to these two portions independently. Hence, an output y can be made to follow sudden changes in a target value r with fast response without the occurrence of overshoots, and the effect of a disturbance input w is alleviated to a maximum. In addition, since integral action is not effected in the adjusting portions, the term of 1 / s<2 >is not included in transfer functions of inputs and outputs, thereby realizing stability of control.
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Description

technical field

[0001] The invention relates to a hydraulic servo type material testing device. Background technique

[0002] In a hydraulic servo type materials testing apparatus, generally, a loading mechanism for applying a load to a test piece is driven by a hydraulic actuator. A target value related to a physical value selected as a control variable is supplied from a waveform generator or the like. At the same time, a load based on the target value is applied to the test piece by feeding back the detected value of the control variable. For example, the physical value selected as the control variable is the displacement of the loading mechanism, the load applied to the test piece due to the displacement, and the like.

[0003] In a hydraulic servo type material testing apparatus having such a feedback loop, so-called PID control is conventionally performed in which a deviation obtained by feeding back a detection value to a target value undergoes a proportional-integr...

Examples

Embodiment Construction

[0025] Now, referring to the drawings, a description will be given of an embodiment of the present invention.

[0026] figure 1 is a schematic diagram of a device according to an embodiment of the present invention, and figure 2 It is a block diagram illustrating the detailed structure of its control system.

[0027] The test device main body 1 has a structure in which two uprights 12a and 12b are provided on a platform 11, and both ends of a transverse bracket 13 are supported by the uprights 12a and 12b.

[0028] A loading mechanism 14 is provided on the platform 11 in which a hydraulic cylinder operated by pressure oil supplied thereto through the servo valve 2 serves as an actuator. The lower jaw 15 a is fitted to this loading mechanism 14 , while the upper jaw 15 b is fitted to the aforementioned transverse support 13 via the load cell 3 . The test piece TP is used in the test in a state where both ends thereof are clamped by the upper and lower jaws 15a and 15b.

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