CN202177999U

CN202177999U - Tool for measuring mechanical efficiency of assembly pulley

Info

Publication number: CN202177999U
Application number: CN2011202971331U
Authority: CN
Inventors: 杨宇帆; 杨立华
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-08-16
Filing date: 2011-08-16
Publication date: 2012-03-28
Anticipated expiration: 2021-08-16

Abstract

Disclosed is a tool for measuring the mechanical efficiency of an assembly pulley. The tool is characterized by comprising an assembly pulley, a spring dynamometer, a lightweight board, a filament, a hook weight, and an electromotor, wherein the lightweight board is provided with two calibrated scales having different lengths; the pulley hook above the hook weight is provided with a small pointer; the lower end of the spring dynamometer is provided with another small pointer; the assembly pulley, the spring dynamometer and the hook weight are connected via the filament; the movable pulley of the assembly pulley is driven by the motor; and the electromotor is a bidirectional electromotor. The tool of the utility model features simple structure, convenient operation, visual reflection, accurate measuring result and excellent demonstration effect and is suitable for being promoted in middle schools.

Description

A kind of instrument of measuring the mechanical efficiency of pulley blocks

Technical field

The utility model relates to a kind of Physical Experiment instrument, particularly relates to a kind of instrument that is used for measuring the mechanical efficiency of pulley blocks.

Background technology

Measurement mechanical efficient in junior physics be an emphasis also be a difficult point, teaching material makes every effort to probe into through experiment, lets the student obtain the most lively experimental fact, further understands mechanical efficiency; Grasp the experimental technique of science simultaneously, the mechanical efficiency of pulley blocks is measured by association.Therefore through experiment, can let the student further be familiar with the process and method that science is probed into, cultivate scientific and precise, realistic experiment custom and scientism, and the coordination ability and cooperative spirit.The current experiments instrument has following deficiency: 1, use iron stand fabricated sheave group, and heavy, carry inconvenience.Take fixedly rule to measure when 2, weight lifting height and rope free end displacement are measured, but rule bad fixing on iron stand, and reading error is bigger.When 3, at the uniform velocity promoting weight straight up in the experiment, be difficult to guarantee at the uniform velocity upwards to promote, experiment effect is poor.Therefore how to organize good student's inquiry activity, how to improve the success ratio of experiment, make experimental phenomena more directly perceived, experimental result is more accurate, is the most important thing of teaching.

Summary of the invention

The purpose of the utility model is to provide a kind of success ratio of experiment high, and experimental phenomena is directly perceived, and experimental result is the survey instrument of the mechanical efficiency of pulley blocks accurately.

The technical scheme that the utility model adopts is: a kind of instrument of measuring the mechanical efficiency of pulley blocks; It is characterized in that: include pulley blocks, weight beam, lightweight plank, fine rule, hook sign indicating number, motor; Two rules that are uneven in length are arranged on the described lightweight plank; A little pointer is equipped with at pulley hook place above the hook sign indicating number, in the lower end of weight beam one little pointer is housed also, links to each other through fine rule between pulley blocks, weight beam, the hook sign indicating number; The travelling block of said pulley blocks is by driven by motor, and described motor is a reversing motor.

The utility model adopts plank to replace iron stand to overcome the shortcoming of heavy inconvenience; Utilize motor drives to replace the staff pulling, guarantee that object at the uniform velocity rises, improved the experiment accuracy; Rule and plank are combined together, and adopt the double scale chi, make reading more directly perceived, more accurate, error is littler.The whole apparatus structure of the utility model is simple, and is easy to operate, and phenomenon is directly perceived, and measurement result is accurate, and good demonstration effect is convenient to promote in the middle school.

Description of drawings

Fig. 1 is the structural drawing of the utility model;

Among the figure, the 1st, pulley, the 2nd, weight beam, the 3rd, hook sign indicating number, the 4th, pointer, the 5th, rule, the 6th, fine rule, the 7th, lightweight plank.

Embodiment

According to accompanying drawing and embodiment this utility model is described further below:

Can know from Fig. 1; The utility model includes pulley blocks 1, weight beam 2, lightweight plank 7, fine rule 6, hook sign indicating number 3, motor; Two rules that are uneven in length 5 are arranged on lightweight plank 7, and a little finger of toe pin 4 is equipped with at the pulley hook place above hook sign indicating number 3, in the lower end of weight beam 2 a little pointer is housed also; Link to each other through fine rule 6 between pulley blocks 1, weight beam 2, the hook sign indicating number 3; Wherein the travelling block of pulley blocks is by driven by motor, and motor is a reversing motor, can positive and negative two directions rotate.

Experimental technique: Closing Switch, motor promote the weight segment distance that at the uniform velocity rises, and write down the size of pulling force, and write down the distance that weight and pulling force move; Calculate useful work and the total work done when pulley blocks promotes weight, calculate the pulley blocks mechanical efficiency according to the mechanical efficiency computing formula; With the motor counter-rotation, measure the mechanical efficiency when at the uniform velocity descending again, it is heavy to be convenient to continue to change thing, measures the mechanical efficiency of pulley blocks when promoting that jljl is heavy.

More than show and described ultimate principle of the utility model and the advantage of principal character and the utility model; The technician of the industry should understand; The utility model is not restricted to the described embodiments; The principle of describing in the foregoing description and the instructions that the utility model just is described, under the prerequisite that does not break away from the utility model spirit and scope, the utility model also has various changes and modifications; These variations and improvement all fall in the utility model scope that requires protection, and the utility model requires protection domain to be defined by appending claims and equivalent thereof.

Claims

1. instrument of measuring the mechanical efficiency of pulley blocks; It is characterized in that: include pulley blocks, weight beam, lightweight plank, fine rule, hook sign indicating number, motor; Two rules that are uneven in length are arranged on the described lightweight plank; A little pointer is equipped with at pulley hook place above the hook sign indicating number, in the lower end of weight beam one little pointer is housed also, links to each other through fine rule between pulley blocks, weight beam, the hook sign indicating number; The travelling block of said pulley blocks is by driven by motor, and described motor is a reversing motor.