CN102393277A - Measuring apparatus of rotational inertia of object and method thereof - Google Patents

Abstract

The invention relates to static equilibrium testing apparatus of a machine or a structure part and a method thereof and further relates to measurement of rotational inertia of an object. The invention provides a measuring apparatus of rotational inertia of the object and the method thereof. The apparatus can be operated simply. The apparatus comprises: a flat, which is horizontally placed and is suspended; three slings, which are arranged on the flat; a horizontal support, which is connected with another ends of the slings; force sensors, which are arranged on the each sling; a tiny gap, which is arranged on an edge of the flat; a photoelectric sensor; a photoelectric signal reading device, which is connected with a photoelectric signal sensor. In the invention, a principle is simple. The apparatus and the method are easy to control. Operation is convenient. The apparatus and the method are suitable for most of complex power equipment.

Description

Object rotation inertia measurement mechanism and method

Technical field

The present invention relates to the orthostatic proving installation and the method for machine or structure member, further relate to the mensuration of object rotation inertia.

Background technology

Object rotation inertia is an important physical parameter in the Machine Design; Particularly for complicated, erose object; Its centroid position is to be difficult to rely on observe obtain, must be by means of testing, and the method that the measurement moment of inertia adopts usually in the prior art is: (1) applies certain moment of torsion to object; Measure its angular acceleration then, extrapolate moment of inertia apart from theorem through momentum; (2) adopt the suspension wire arrangement, calculate moment of inertia through the torsional oscillation cycle of measuring it; (3) measure moment of inertia through the single pendulum method.These methods realize complicated, and error is bigger, and lay particular emphasis on the object of measurement quality less than 500kg, therefore, are badly in need of a kind of easy object mass center measurement mechanism and method.

Summary of the invention

The invention provides a kind of object rotation inertia measurement mechanism and method easy and simple to handle.Surpass 500kg for quality, the large-sized power plant that physical dimension surpasses 1.5m has remarkable advantages more.

The technical scheme that the present invention adopted is following:

The object rotation inertia measurement mechanism comprises: the flat board of the unsettled placement of level, and dull and stereotyped geometric shape is that circle or limit number are the regular polygon of 3N, N is the integer more than or equal to 1, is used to hold testee; Be positioned at dull and stereotyped outer rim place, equidistantly distribute, equal length and perpendicular to 3 hoist cables of flat board; The horizontal stand that is connected with hoist cable other end item; Be positioned at the pulling force sensor on the every hoist cable; Be positioned at the small gap of plate edge; The photoelectric sensor of opening position under the static steady state (SS), said photoelectric sensor and support keep fixing position relation, and when flat board along the center of circle minor rotation took place, the signal of photoelectric sensor changed; The photosignal reading device that links to each other with photoelectric signal sensor.

Preferred equilateral triangle of said flat board or regular hexagon, hoist cable are distributed in wherein three summits uniformly.

On said apparatus, realize the object rotation inertia measuring method; Definition: three ropes are respectively first rope, second rope, the 3rd rope; Its length is defined as L, and its corresponding pulling force sensor is respectively first pulling force sensor, second pulling force sensor, the 3rd pulling force sensor, on flat board; Three ropes are defined as first node, second node, the 3rd node respectively with dull and stereotyped node, and dull and stereotyped moment of inertia along vertical center line is defined as I _o, the distance definition at first node, second node, the 3rd node and dull and stereotyped center is R, the acceleration of gravity of measuring the place is defined as g; It is characterized in that step comprises:

Step 1: the adjustment horizontal stand, guarantee to be in same surface level with the node of rope;

Step 2: adjustment is dull and stereotyped, makes it keep surface level;

Step 3: testee is placed on the flat board, and the center of guaranteeing its barycenter and flat board is on same vertical direction;

Step 4: give dull and stereotyped small power, make it with a low-angle torsional oscillation, said angle is greater than 0, and smaller or equal to 5 degree; Read the torsional oscillation cycle T through photoelectric sensor; At this moment, the reading of first, second, third pulling force sensor is respectively F1, F2, F 3; The computing formula of moment of inertia is:

$I=\frac{(F1+F2+F3)*R^2*T^2}{4{\mathrm{\π}}^2*L}-I_O.$

The principle of the invention is simple, is easy to control, is convenient to operation, is suitable for the power-equipment of most of complicacies.

Description of drawings

Fig. 1 is the synoptic diagram of embodiment.1 represents support among the figure, and 2 represent pulling force sensor; 3 represent testee, and 4 represent hoist cable, and 5 represent the rope lengths regulating device, and 6 represent flat board, and 7 represent charge amplifier, and 8 represent computing machine, and 9 represent photoelectric sensor.

Embodiment

Map 1 explanation embodiment of the present invention.

The object rotation inertia measurement mechanism comprises: the flat board 6 of the unsettled placement of level, dull and stereotyped geometric shape are circular, are used to hold testee 3; Be positioned at dull and stereotyped outer rim place, equidistantly distribute, equal length and perpendicular to 3 hoist cables 4 of flat board; The horizontal stand 1 that is connected with hoist cable other end item; Be positioned at the pulling force sensor 2 on the every hoist cable; Be positioned at the small gap of plate edge; The photoelectric sensor 9 of opening position under the static steady state (SS), said photoelectric sensor and support keep fixing position relation, and when flat board during along center line generation minor rotation, the signal of photoelectric sensor changes; The photosignal reading device that links to each other with photoelectric signal sensor---computing machine 8.

On said apparatus, realize the object rotation inertia measuring method; Definition: three ropes are respectively first rope, second rope, the 3rd rope; Its length is defined as L, and its corresponding pulling force sensor is respectively first pulling force sensor, second pulling force sensor, the 3rd pulling force sensor, on flat board; Three ropes are defined as first node, second node, the 3rd node respectively with dull and stereotyped node, and dull and stereotyped moment of inertia along vertical center line is defined as I _o, the distance definition at first node, second node, the 3rd node and dull and stereotyped center is R, the acceleration of gravity of measuring the place is defined as g; It is characterized in that step comprises:

Step 1: the adjustment horizontal stand, guarantee to be in same surface level with the node of rope;

Step 2: realize that through regulating rope lengths regulating device 5 adjustment is dull and stereotyped, make it keep surface level;

Step 3: testee is placed on the flat board, and the center of guaranteeing its barycenter and flat board is on same vertical direction;

Step 4: give dull and stereotyped small power, make it with a low-angle torsional oscillation, said angle is greater than 0, and smaller or equal to 5 degree; Read the torsional oscillation cycle T through photoelectric sensor; At this moment, the reading of first, second, third pulling force sensor is respectively F1, F2, F3; The computing formula of moment of inertia is:

$I=\frac{(F1+F2+F3)*R^2*T^2}{4{\mathrm{\π}}^2*L}-I_O;$ $I_O=\frac{1}{2}{\mathrm{MR}}^2.$

Claims (3)

1. The measuring device for moment of inertia of an object is characterized in that it comprises: A flat plate placed horizontally in the air. The geometric shape of the flat plate is a circle or a regular polygon with sides of 3N, where N is an integer greater than or equal to 1, and is used to hold the measured object; 3 slings located at the outer edge of the slab, equally spaced, of equal length and perpendicular to the slab; A horizontal bracket connected to the other end item of the sling; Tension sensors located on each sling; A tiny nick at the edge of the slab; A photoelectric sensor located at the gap in a static and stable state, the photoelectric sensor maintains a fixed positional relationship with the support, and when the plate rotates slightly along the center line, the signal of the photoelectric sensor changes; A photoelectric signal reading device connected with a photoelectric signal sensor. 2 . The device for measuring the moment of inertia of an object according to claim 1 , wherein the flat plate is an equilateral triangle or a regular hexagon, and the slings are evenly distributed at three vertices thereof. 3. Realize the object moment of inertia measurement method on the device described in claim 1, define: three ropes are respectively the first rope, the second rope, the third rope, and its length is defined as L, and its corresponding tension sensor is respectively the first The tension sensor, the second tension sensor, and the third tension sensor, on the plate, the nodes of the three ropes and the plate are respectively defined as the first node, the second node, and the third node, and the moment of inertia of the plate along the vertical centerline Defined as _Io , the distance between the first node, the second node, the third node and the center of the plate is defined as R, and the gravitational acceleration of the measurement site is defined as g; it is characterized in that the steps include: Step 1: Adjust the horizontal support to ensure that it is at the same level as the knot of the rope; Step 2: Adjust the flat panel to keep it horizontal; Step 3: Place the object to be measured on the plate and ensure that its center of mass is in the same vertical direction as the center of the plate; Step 4: Give the plate a small force to make it torsionally vibrate at a small angle, the angle is greater than 0 and less than or equal to 5 degrees; read the torsional vibration period T through the photoelectric sensor; at this time, the first, second, and second The readings of the three tension sensors are F1, F2, and F3 respectively; the calculation formula of the moment of inertia is: $\mathrm{<span\; class="notranslate">\; I</span>}<span\; class="notranslate">\; =</span>\frac{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; f</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; f</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; f</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; R</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; *</span>{\mathrm{<span\; class="notranslate">\; T</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 4</span>}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}}<span\; class="notranslate">\; .</span>$

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