CN201177548Y

CN201177548Y - Concave three-wire pendulum chassis

Info

Publication number: CN201177548Y
Application number: CNU2008200619416U
Authority: CN
Inventors: 梁德富; 王维果
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2008-01-23
Filing date: 2008-01-23
Publication date: 2009-01-07
Anticipated expiration: 2018-01-23

Abstract

The utility model provides a concave three-string pendulum chassis. The chassis has a circular step type concave structure, the periphery of the bottom surface has a step-typed multiple cylinder surface structure, a circular ring in the concave surface and the cylinder surface of the periphery as well as the center of the chassis are coaxial, the vertical thickness of the periphery cylinder surface is the same as the depth of the last step of the corresponding step in the concave surface, the bottom of the concave surface has a circular plane, and the outer edge of the upper end surface of the chassis is fixed with three hooks which are distributed in 120 degrees corresponding to the center of the chassis. The concave three-string pendulum chassis ensures that the mass centers of the chassis and the piece to be detected are in the same vertical line.

Description

Concave surface three string pendulum chassis

Technical field:

The utility model relates to a kind of three string pendulums, particularly a kind of three string pendulum chassis of card steps concave surface.

Background technology:

With three string pendulum Measuring Moment of Inertia Using are ancient physical and mechanical experiments.As the most basic, the most important parts of this experimental provision are chassis.Known three string pendulum chassis all are circular dull and stereotyped.The greatest drawback on this flat chassis is to guarantee to place the barycenter on the barycenter of the test specimen on the chassis and chassis coaxial.The condition precedent of this measurement then requires the two must be coaxial, and only in this way, the theoretical calculation formula that is used for this measurement is just set up, otherwise will cause bigger experimental error.Because the chassis is dull and stereotyped, so whether the barycenter on test specimen and chassis is coaxial, then depends on operator's visual resolving power and experience fully, there is no objective standard, so and the measuring error of generation is also just unavoidable.

The utility model content:

The purpose of this utility model provides a kind of concave surface three string pendulum chassis, and is coaxial with the barycenter on the barycenter of guaranteeing test specimen to be measured and chassis.

The purpose of this utility model is achieved in that the chassis of three string pendulums is a step cutting pattern formula concave surface, the progression of step is 2～5 grades, except that subordinate is the circular flat, the bottom surface of all the other each grade steps is the annular plane, its width is not less than 5mm, the bottom surface is vertical with sidewall, the degree of depth of steps at different levels is not necessarily identical, its degree of depth all is not less than 3mm, the diameter of steps at different levels is consistent with the diameter of the face of cylinder to be measured test specimen that matches with this step respectively, tolerance clearance each other is 0.01mm～0.02mm, the upper surface, chassis is that width is the planar annular of 1～2cm, the lateral surface on chassis is the circular cylinder of step, the transverse gage of each grade cylinder is not less than 5mm, the vertical thickness of upper level cylinder is identical with the thickness of center chassis point, from second level cylinder, the vertical height of each grade cylinder is all identical with the degree of depth of corresponding upper level step in the concave surface of chassis, the cylinder in the annulus of inboard, chassis and the outside, chassis is all concentric with the vertical center line on chassis, the upper surface, chassis is fixed with the hook that is mutually 120 degree angles with respect to core, the diameter of the basic point of each hook is 1～2mm, the distance of end face outer equates and is not more than 5mm therewith, the quality of each hook is not more than 1g, the chassis overall diameter is not less than 20cm, and the thickness at center chassis point place is not less than 10mm.

Adopt such scheme can receive following remarkable result:

1, test specimen to be measured such as cylinder, cylinder, annulus and spheroid are put into conveniently the step convex surface on chassis, can guarantee that promptly the barycenter of these test specimens and the barycenter on chassis are on the same vertical curve, make both coaxial in rotation, can make again in the test specimen rotation and be in steady state (SS), thereby eliminated measuring error in this measurement, and shortened the adjusting time of instrument significantly.

2, because this programme can be guaranteed the radially homogeneity of mass distribution of chassis, so need not change the computing formula that it changes inertia.

3, Chang Gui three string pendulums can't be surveyed the moment of inertia of spheroid, and this programme then can be realized easily.

Description of drawings

Fig. 1 is the sectional view on concave surface three string pendulum chassis.

Embodiment

The chassis of three string pendulums is a step cutting pattern formula concave surface, the progression of step is 2.5 grades, except that subordinate is the circular flat, the bottom surface of all the other each grade steps is the annular plane, its width is not less than 5mm, the bottom surface is vertical with sidewall, the degree of depth of steps at different levels is not necessarily identical, its degree of depth all is not less than 3mm, the diameter of steps at different levels is consistent with the diameter of the face of cylinder to be measured test specimen that matches with this step respectively, tolerance clearance each other is 0.01mm, the upper surface, chassis is that width is the planar annular of 1.5cm, the lateral surface on chassis is the circular cylinder of step, the transverse gage of each grade cylinder is not less than 5mm, the vertical thickness of upper level cylinder is identical with the thickness of center chassis point, from second level cylinder, the vertical height of each grade cylinder is all identical with the degree of depth of corresponding upper level step in the concave surface of chassis, the cylinder in the annulus of inboard, chassis and the outside, chassis is all concentric with the vertical center line on chassis, the upper surface, chassis is fixed with the hook that is mutually 120 degree angles with respect to core, the diameter of the basic point of each hook is 1.5mm, the distance of end face outer equates and is not more than 5mm therewith, the quality of each hook is not more than 1g, the chassis overall diameter is not less than 20cm, and the thickness at center chassis point place is not less than 10mm.

Claims

1, a kind of concave surface three string pendulum chassis, it is characterized in that: the chassis of three string pendulums is a step cutting pattern formula concave surface, the progression of step is 2～5 grades, except that subordinate is the circular flat, the bottom surface of all the other each grade steps is the annular plane, its width is not less than 5mm, the bottom surface is vertical with sidewall, the degree of depth of steps at different levels is at 5～10mm, the diameter of steps at different levels is consistent with the diameter of the face of cylinder to be measured test specimen that matches with this step respectively, tolerance clearance each other is 0.01mm～0.02mm, the upper surface, chassis is that width is the planar annular of 1～2cm, the lateral surface on chassis is the circular cylinder of step, the transverse gage of each grade cylinder is not less than 5mm, the vertical thickness of upper level cylinder is identical with the thickness of center chassis point, from second level cylinder, the vertical height of each grade cylinder is all identical with the degree of depth of corresponding upper level step in the concave surface of chassis, the cylinder in the annulus of inboard, chassis and the outside, chassis is all concentric with the vertical center line on chassis, the upper surface, chassis is fixed with the hook that is mutually 120 degree angles with respect to core, the diameter of the basic point of each hook is 1～2mm, the distance of end face outer equates and is not more than 5mm therewith, the quality of each hook is not more than 1g, the chassis overall diameter is not less than 20cm, and the thickness at center chassis point place is not less than 10mm.