thmdtk1变速箱

2022-09-20

第一篇:thmdtk1变速箱

牛头刨床变速箱设计说明书英文版(推荐)

<<机械CAD/CAM>>课程设

姓名:徐晨晨

扬州大学 机械工程学院

Catalog

1、The design task book: shaper transmission CAD / CAM design……V

Design: shaper gearbox………………………………………………………V

2、Analysis of transmission plan and development The choice of motor

Working conditions and production conditions: continuous unidirectional operation, stable load, shifts at work, use the period of 10 years, small batch production. Reel diameter and D / mm 350 The transport belt velocity V ( M / s )1.20 The transport belt required torque F ( KN )3.6 Analysis of transmission plan and development

Figure 1-1belt conveyer transmission scheme Belt conveyor is driven by an electric motor. Motor through a coupler to incoming power reducer, by coupling the power is transmitted to the roller conveyer, drives the conveyer belt to work. The transmission system adopts two stage helical gear reducer, which has the advantages of simple structure, but the gear relative bearing asymmetrical position, thus requiring shaft has high rigidity, high level and low level using the cylindrical helical gear drive. The choice of motor Motor type selection Motor type according to the power source and working conditions, select Y series three-phase asynchronous motor. Motor power of choice. According to known conditions calculates machine speed: = 60000/ 3.14x 300= 63.694 R / min Working machine is needed for effective power: = 3600/1000 =3.6 kW In order to calculate the required motor power, to determine from the motor to the work between the machine and the total efficiency. A flexible coupling efficiency is 0.99, for rolling bearing transmission efficiency of 0.99, for the gear transmission (8) efficiency0.97, the efficiency of 0.96drum. The transmission device for total efficiency: 0.851 Motor power required for: 3.6 /0.851 = 4.23kW In the mechanical transmission used in synchronous speed is 1500r / min and 1000r / min two motor, the motor according to the required power and the synchronous speed by [2], P14816-1check motor technical data and calculates the total transmission such as shown in table31. Table11motors technical data and calculate the total transmission ratio

For more than two kinds of schemes for calculating, option 1is appropriate and scheme 1motor minimum quality, cheap price. Selection of scheme 1motor model Y112M-4, according to [2] P14916-2check motor of main parameters such as shown in table32. Table12Y112M-4 motor main parameters

The 1.2device motion and dynamic parameter calculation 1.2.1 transmission total transmission ratio and the distribution of various transmission ratio According to motor full load speed and rotate speed of the roller can be used to calculate the total transmission ratio transmission device: 1440 /63.964 =22.61 Double cylinder gear deceleration device assigned to the levels of transmission ratio: The high speed transmission ratio: = = = 5.52 The low-speed transmission ratio: = / = 22.61/ 5.52= 4.10 1.2.2 transmission device of power and motion parameter calculation: A ) the shaft rotating speed calculation: = = = = = = = = = = = =1440r / min = / = 1440/5.52 = 260.870r / min = / = 260.870/4.10 = 63.694r / min = = = = = = = = = = = =63.694r / min B ) the axis of the input power calculation: = = = = = = = = = = = =3.0550.99 = 3.024kW 3.024 = =0.970.99 = 2.904kW 2.904 = =0.970.99 = 2.789kW = = = = = = = = = = = =2.7890.99 x0.99 = 2.733kW C ) the axis of the input torque calculation: = 955095503.055/1440 = 20.26N M = x = 20.26x 0.99= 20.06 N M = x x x = 20.06x 5.52x 0.99x 0.97= 106.34 N M = x x x = 106.34x 4.10x 0.99x 0.67= 418.69 N M = x = 418.69x 0.99 x0.99 = 410.36N M From the above data of each axis motion and dynamic parameters are shown in table13. 1-3each axis motion and dynamic parameters

Design and calculation of transmission parts The design of cylindrical gear reducer selection standard cylindrical gear transmission. Standard for structural parameters of pressure angle, tooth addendum coefficient, coefficient of top clearance. 2.1 high speed cylindrical gear design and calculation 1) selection of gear materials and heat treatment: Due to the soft tooth surface gear for gear compact size and high precision, small load in low speed. According to the design requirements are selected to soft tooth surface combination: According to [1] P1028-1: The small gear selection of 45 steel quenching and tempering, HBS = 217~ 255; Gear steel is45, HBS = 162~ 217; The two gear minimum hardness difference of 217-162= 55; that value slightly somes small, can be a preliminary trial. 2) the selection of the number of teeth: Now the soft tooth surface gear, tooth root cutting of more than tens is appropriate, primaries = 23 = = = = = = = = = = = = = = = = = =126.96x5.5223 Taking the gear tooth number = 127, then the gear ratio (i.e. the actual ratio ) = / = 127/ 23= 5.5217. With the original requirements only (5.1328-5.1304) / 5.1304= 0.05%, so it can meet the requirements of. 3) choice of helix angle beta: According to the experience,8< < 20degrees, is now the primary = 13degrees 4) calculate the equivalent number of teeth, tooth shape coefficient: Z = Z / cos beta = 23/ cos 13DEG = 24.8631 Z = Z / cos beta = 127/ cos 13DEG = 137.30 From [1] P111table 8-8linear difference obtained: 5) selection of tooth width coefficient: As the reducer for expansion type double stage gear transmission, so the gear relative to the support only for the asymmetric simple structure, so the tooth width coefficient election should not be too large, reference [1]8-5, chosen as 0.7~ 1, choose now = 0.8 6) select Load coefficient: Reference [1] P1068-3, composed of a gear bearing medium impact load, selected load coefficient K is 1.2~ 1.6. Take K = 1.3. 7) calculation of I gear shaft torque TI: 9550000x 3.024/1440 =20100 N mm 8) calculate the geometric parameters: Tan = Tan / cos = TG20/ cos13= 0.374 = = = = = = = = = = = =20.5158 degrees Sin = sin cos = = sin13x cos20= 0.213 = = = = = = = = = = = =12.2103 degrees = 1.68 = 1/ z1tg = 1/ 3.14159=0.823tg13=1.35 9) according to the tooth surface contact fatigue strength design: Regional coefficient:2.4414 Elastic coefficient: Z = 189.8 From [1] P1098-6and safety coefficient S = 1 Allowable contact stress: The small gear pitch circle diameter: Calculation method of surface modulus M M = cos D / z = cos13=36.513 /23 =1.53 mm 10) according to the tooth root bending fatigue strength design: Calculation of helix angle coefficient Y = 1.35> 1, because, according to the calculation of1: Y = 1= 0.892=11 Calculation of tooth shape coefficient and stress ratio: Y / [ ] = 2.7002/ 148.9744= 0.018 Y / [ ] = 2.1365/ 137.1795= 0.016 As a result of Y / [ ] is larger, with a small gear parameter Y / [ ] into the formula, calculation of gear needed for normal module: = = = = = = = = = = = =1.078 11) decide modulus Due to the design of the soft tooth surface gear drive, the main failure is fatigue pitting of tooth surface, if small, may also occur gear fatigue fracture. So compared with the two calculated results, according to the contact fatigue strength for gear modulus larger, prone to pitting failure, namely to Mn =1.53mm. According to the standard module table, tentative modulus: M =2.0mm 12) calculation of center distance: 2(23+127) /2cos13= 154.004mm After standardization for a =154mm 13) correction of spiral angle beta According to the criteria of center distance correction author: 14) calculation of surface modulus: 15) calculation of transmission to other dimensions: 16) calculation on the tooth surface load: 17) selection of precision grade The circumferential speed gear: 3.558 M / S Control [1] P1078-4, for transport for general machinery, so choose the gear accuracy level of 8is appropriate. 18) gear graph:

2.2 speed gear transmission design and calculation 1) selection of gear materials and heat treatment: Due to the soft tooth surface gear for gear compact size and high precision, small load in low speed. According to the design requirements are selected to soft tooth surface combination: According to [1] P1028-1: The small gear selection of 45 steel quenching and tempering, HBS = 217~ 255; Gear steel is45, HBS = 162~ 217; The two gear minimum hardness difference of 217-162= 55; that value slightly somes small, can be a preliminary trial. 2) the selection of the number of teeth: Now the soft tooth surface gear, tooth root cutting of more than tens is appropriate, primaries = 25 = = = = = = = = = = = =4.1025 =102.5 Large gear tooth number Z = 103, then the gear ratio (i.e. the actual ratio ) = Z / Z1 = 103/ 25= 4.12. With the original requirements only (4.12-4.10) / 4.10= 0.487%, so it can meet the requirements of. 3) choice of helix angle beta: According to the experience,8< < 20degrees, the primaries = 12degrees 4) calculate the equivalent number of teeth, tooth shape coefficient: Z = 1/ cos = 25/ cos 12DEG = 26.709 = Z / cos = 103/ cos 12DEG = 110.043 From [1] P111table 8-8linear difference obtained: 5) selection of tooth width coefficient: As the reducer for expansion type double stage gear transmission, so the gear relative to the support only for the asymmetric simple structure, so the tooth width coefficient election should not be too large, reference [1]8-5, chosen as 0.7~ 1.15, choose now = 0.8 6) select Load coefficient: Reference [1] P1068-3, composed of a gear bearing medium impact load, selected load coefficient K is 1.2~ 1.6. Take K = 1.3. 7) calculation of II gear shaft torque TII: 106300 N M 8) calculate the geometric parameters: Tan = Tan / cos = tan20/ cos12= 0.372 = = = = = = = = = = = =20.415 degrees Sin = sin cos = sin12cos20= 0.195 = = = = = = = = = = = =11.27 degrees = 1.68 = 1/ z1tan = 1/ 3.14159=0.825tan12=1.35 9) according to the tooth surface contact fatigue strength design: Coefficient of region: Z = = 2.449 Elastic coefficient: Z = 189.8 K = 1 =450.000MPa S = 1 Allowable contact stress: The small gear pitch circle diameter: Calculation method of surface modulus m: M = cos D / z = cos12=64.868 /25 = 2.53mm 10) according to the tooth root bending fatigue strength design: Calculation of helix angle coefficient Y = 1.35> 1, because, according to the calculation of1: Y = 1= 0.9083=11 Calculation of tooth shape coefficient and stress ratio: Y / [ ] = 2.585/ 144.846= 0.0178 Y / [ ] = 2.174/ 134.615= 0.016 As a result of Y / [ ] is larger, with large gear parameter Y / [ ] into the formula Calculation of gear needed for normal module: = = = = = = = = = = = =1.777 11) according to the contact strength decision model numerical, take M =2.5mm 12) calculation of center distance: A = m ( z1+ Z ) /2cos = 2.5(25+103/2cos12= 163.599 mm ) After standardization for a =164mm 13) correction of spiral angle beta: According to the criteria of center distance correction author: 14) calculation of surface modulus: 15) calculation of transmission to other dimensions: 16) calculation on the tooth surface load:

Main parameters of gears Three axis structure design and calculation The shaft is composed of the main parts of mechanical, it supports other rotary parts and transfer torque, at the same time it through a bearing and a frame connection. All parts on the shaft around the axis of motion, the formation of a shaft for baseline combination -- shafting components. 3.1 structural design of shaft 3.1.1 initially identified the smallest diameter of axis Select the shaft material for 45 steel quenching and tempering treatment. According to the estimation of the diameter of the shaft torsional strength, by [1] P207 12- 2. High speed shaft: take A = 116 Mm Intermediate : take = 112 = = = = = =112 = 25.007mm The low speed shaft : take = 107 = 37.714mm Determination of the structure and size of3.1.2axis Selection and calculation of shaft 1 for I axis through the shaft coupling and motor shaft diameter 28mm, check coupling standard, selected coupling elastic pin coupling. The standard model HL2, and coupling connected shaft diameter selection for25mm. The 2parts of the axial positioning with positioning shaft. H >0.07d. In order to processing and assembly are convenient and setting a positioning shaft shoulder, which is generally 2II and coupling. 5 IIIV position for bearing. 7IVVI for gear shaft. 9VI937207C angular contact ball bearing. 2 in accordance with the shaft shoulder specifications. The shaft structure, and the positioning relationship. IIII for the gear face and the inner wall and part of the inner wall of the gap distance. IVVI for the low-speed and high-speed gear tooth end surface distance. VIII section as the sleeve is positioned and mounted bearing. IIIV section is positioned between the shaft gear. IVVI position for bearing. VI - VII section as the wrench space location and the bearing end cover. VII, VIII and coupling. Bearing specific dimensions as shown

第二篇:自动变速器 — 概述

【课题】 汽车传动系

【教学内容】高等教育出版社第二版 第一章 第四节 自动变速器概述 第

15、16课时 【教学目标】

知识目标:了解自动变速器的发展历史。

能力目标:掌握自动变速器的分类。 情感目标:培养学生认真观察的能力。 【教学重点】自动变速器的分类。 【教学难点】自动变速器的组成。

【教学准备】 多媒体PPT,自动变速器动画。 【教法学法】 演示教学法,讲授法,合作学习法。 【教学过程】

1.新课导入

播放自动变速器的视频,让学生与手动变速器进行对比。 新课进程

一、变速器的发展状况。

(1) 手动变速器MT (手动操控-有级)操控感强。 (2) 自动变速器AT (自动控制-有级)方便,舒适。

(3) 无级变速器CVT(自动控制-无级)舒适性好,经济性好,但其成本高,钢带易打滑(应用于小功率的汽车)。

二、自动变速器的发展史。

(1)二战时期开始研制

(2)1948年出现了可根据车速和节气门位置变化进行自动换档的自动变速器 (3)经过40年的发展,自动变速器于80年代广泛应用于国外的汽车上 (4)21世纪初,在中国开始批量装配

三、自动变速器的优点。 (1)减轻驾驶员的负担

(2)减少传动过程中的冲击,提高了系统寿命和乘坐舒适性 (3)起步、加速平稳 (4)电脑控制、降低排放污染

四、AT的类型

(一)按变速器内部结构的不同可分为:

(1)后驱动型AT:用于FR车辆,输入轴与输出轴同轴线,长度尺寸较长。

(2)前驱动型AT :也称自动驱动桥,用于FF车辆,内部还装有主减速器与差速器,输入轴与输出轴呈前后平行布置,横向尺寸较宽,长度尺寸较短。

(二)按变速器内部所采用齿轮形式的不同可分为: (1)普通齿轮,又称固定轴式。 (2)行星齿轮,又称旋转轴式。

(三)按变速器换档控制方式的不同可分为: (1)液压控制式(液压式)

将决定变速器档位的汽车运行参数转变成液压信号,利用液压控制原理实现对变速器档位的控制。

(2)电子液压控制式(电液式)

将决定变速器档位的汽车运行参数转变成电压信号,利用电子控制原理和液压控制原理实现对变速器档位的控制。

(四)按变速器前进档位数的不同可分为: 2档:如红旗CA770轿车;

3档:如雪佛莱子弹头的3T40型变速器;(2档与3档的变速器已经越来越少) 4档:如别克轿车的4T65E型变速器;(应用广泛,绝大多数变速器都是4档式) 5档:如德国ZF公司的5HP-18型变速器;(新生产的豪华车开始采用5档式)

(五)按变速器功能的不同可分为:

(1)单纯自动式:只有一种功能,即按自动变档方式工作。(大都数AT都采用这种) (2)自动/手动一体式:既可以按自动变速方式运行,又可以以手动换档方式运行。

五、结构组成

(1)变矩器(4元件带锁止离合器的居多)。

(2)齿轮传动装置,辛普森行星轮系(应用最多);拉维奈行星轮系(结构紧凑);平行轴式圆柱齿轮系(本田汽车)。

(3)阀体 (全液控电液控-电磁阀应用越来越多)。 (4)操纵部分。

课堂小结:1。自动变速器的优点。

2.AT的类型。

知识验收:1.按变速器内部所采用齿轮形式的不同可分为。

2.按变速器前进档位数的不同可分为。

作业布置:1.简述自动变速器的优缺点?

2.AT的变速器的分类有那些?

【课后反思】本次利用多媒体PPT和相关的动画进行演示,在知识的突破上取得了明显的效果,学生的参与度也很高,课堂氛围好。 【安全与法治教育】

第三篇:变速器拆装总结

以AE431为例

变速器是汽车传动系中最主要的部件之一。

它的作用是:

1.在较大范围内改变汽车行驶速度的大小和汽车驱动轮上扭矩的大小。

由于汽车行驶条件不同,要求汽车行驶速度和驱动扭矩能在很大范围内变化。例如在高速路上车速应能达到100km/h,而在市区内,车速常在50km/h左右。空车在平直的公路上行驶时,行驶阻力很小,则当满载上坡时,行驶阻力便很大。而汽车发动机的特性是转速变化范围较小,而转矩变化范围更不能满足实际路况需要。

2.实现倒车行驶

汽车发动机曲轴一般都是只能向一个方向转动的,而汽车有时需要能倒退行驶,因此,往往利用变速箱中设置的倒档来实现汽车倒车行驶。

3.实现空档

当离合器接合时,变速箱可以不输出动力。例如可以保证驾驶员在发动机不熄火时松开离合器踏板离开驾驶员座位。

变速箱由变速传动机构和变速操纵机构两部分组成。变速传动机构的主要作用是改变转矩和

转速的数值和方向;操纵机构的主要作用是控制传动机构,实现变速器传动比的变换,即实现换档,以达到变速变矩。

机械式变速箱主要应用了齿轮传动的降速原理。简单的说,变速箱内有多组传动比不同的齿轮副,而汽车行驶时的换档行为,也就是通过操纵机构使变速箱内不同的齿轮副工作。如在低速时,让传动比大的齿轮副工作,而在高速时,让传动比小的齿轮副工作。

组成部分:

液力变矩器、行星齿轮机构、离合器、制动器、油泵、滤清器、管道、控制阀体、速度调压器等,按照这些部件的功能,可将它们分成液力变矩器、变速齿轮机构、供油系统、自动换挡控制系统和换挡操纵机构等五大部分。

注意事项:

1. 找一个干净无灰尘的场地,利用拆卸工具和铜棒,开始拆卸变速器。拆卸顺序一般是:变速器盖、第一轴、第二轴、中间轴、倒挡轴。

2. 拆卸零件时,先看好零件原始的方向和位置后再拆卸,必要时,做好记录;拆下的零件按拆卸先后顺序,分部位排放整齐,必要时可用线或铁丝将各零件按顺序串在一起,像一些细小的零件更要注意些,如:弹簧、节流阀、柱塞、锁销等;齿轮可按原方向和位置套在轴上,以防装错或漏装。

3. 拆卸的所有零件都应该清洗干净,并做相应检查,不能继续使用的应该予以更换;拆卸过的油封、密封垫一般不应该继续使用,应该更换。

4. 装配前各轴承、油封、轴上的键槽、齿轮的内孔以及变速器箱体的轴承孔涂上齿轮油或机油,并将要更换的纸垫浸透机油。

5. 装配顺序与拆卸顺序相反,即后拆下的零件先装,使全部零件都安装到原来的位置上,安装过程中要常转动配合件,注意油封的方向且不得有破损。

6. 在安装变速器盖前,应检查场地有无漏装的零件,各轴及固定齿轮是否有轴向窜动,各处纸垫是否完好,各对啮合齿轮是否在全部齿宽内啮合;用手拨动滑动齿轮,看能否轴向移动到全齿宽啮合;用手转动第一轴,分别试一下各挡,都应能灵活平稳转动,无卡涩现象。按规定在变速箱体内加入适量的润滑油。

制动变速器的解体:

1.卸自动变速器前后壳体、油底壳及阀体。

1) 拧下放油塞螺栓,将残余在变速器内的油液卸掉。

2) 将装在变速器上的附件拆除:档位开关、车速传感器、输入轴传感器等。 3) 拆下前后壳体。

4) 拆下油底壳:19个10号的螺栓。

5) 拆卸阀板:阀体上的线束和电磁阀,再拆下阀板,取下蓄压器4个。

2.拆卸液力变矩器和油泵。 1) 拆卸液力变矩器。

2) 拆卸油泵:有专用工具用专用工具,如果没有专用工具:左右摇晃拔出。

3.分解行星齿轮变速器:

1) 从自动变速器前方取出超速行星架和直接离合器组件和超速齿圈。

2) 拆卸超速制动器:用起子拆下超速制动器卡环,取出超速制动器钢片和摩擦片。拆下超速制动器鼓的卡环,松开壳体上的固定螺栓,用拉具拉出超速制动器鼓。 3) 拆卸2档强制制动器活塞:从外壳上拆下2档强制制动带液压缸盖卡环,取下液压缸盖和活塞。取出中间轴、高档及倒档离合器和前进离合器组件。 4) 拆下2档强制制动带销轴,取下制动带。

5) 拆出前行星排,拆下前行星架上的卡环,拆出前行星架组件和行星齿轮组件。 6) 取出前后太阳轮组件和低档单向离合器。 7) 拆卸2档制动器:拆下卡环,取出2档制动器的所有摩擦片、钢片及活塞套。拆卸输出轴、后行星排和低档及倒档制动器组件:拆下卡环,固定输出轴,取出输出轴、后行星排、前进单向超越离合器、低档及倒档制动器和2档制动器鼓组件。

8) 在分解自动变速器时,应将所有组件和零件按分解顺序依次排放,以便于检修和组装。要特别注意各个止推垫片、止推轴承的位置,不可错乱。

4.由于液压阀板的零部件比较繁多,阀板中各个控制阀的加工精度和配合度都极高,不正确的安装、检修都损坏控制阀,影响其正常工作,因此在此重点讲解下拆卸的注意事项: 1) 拆检阀板时,不可让阀芯等重要零件掉落。不要将铁丝、起子等硬物伸入阀孔中,以免损伤阀芯和阀孔的精密配合表面。 2) 阀板解体后的所有零件在清洗后,可用压缩空气吹干,不允许用棉布擦拭,以免粘上细小的纤维丝,造成控制阀卡滞。 3) 装配阀板时,应检查各控制阀阀芯是否能在阀孔中活动自如。如有卡滞,应拆下,经清洗后重新安装。 4) 不要在阀板衬垫及控制阀的任何零件上使用密封胶或粘合剂。 5) 拆出阀板所有的控制阀,在拆出每个控制阀时,应先取出锁销和柱塞,在让阀芯或弹簧从阀孔中自由落出。若阀芯在阀孔中有卡滞,不能自由落出,可用木锤或橡皮锤敲击阀板,将阀芯震出:不要用铁丝或钳子伸入阀孔去取阀芯,以免损坏阀孔内径或阀芯。

总结:

通过本次的学习,我们对变速器有了进一步的了解。不管从变速器的拆装上熟练度上,还是从变速器的工作原理以及传递路线上,都有了更深了解和更新的概念。在拆装过程中,我们以拍摄制作文档的形式研究学习,不解的地方与老师一起探讨,学习过程轻松、深刻。将复杂的自动变速器,在这种方式下,深刻清晰的刻印在脑海之中。对以后的学习和工作上都有较大的帮助。学习一种型号,不如学习一种方法。相信在即将到来的的工作、学习里,我们能用自己的实力锻造自己的未来。

第四篇:自动变速器档位介绍

1.档位介绍

所谓自动档,顾名思义就是不用驾驶者去手动换档,车辆会根据行驶的速度和交通情况自动选择合适的档位行驶。但是自动变速箱为什么还有那么多档位呢~现在就先把自动变速箱的各个档位及功能做个简单的介绍。

先以本田新雅阁为例~新雅阁的变速箱有P,R,N,D,3,2,1几个档位,

P代表泊车档,停车时使用(关闭发动机时和较长时间怠速停车)!~

R代表倒车档,这个相信不用我解释吧!~

N代表空档,和手动档的空档一个意思,用于短暂停车时使用!~

D表示前进档,这个档位下变速箱会在1~5档根据速度和油门情况自动切换~

3同样是前进档,这个档位下变速箱在1~3档自动切换,不会升入

4、5两档。可在交通不太通畅的时作为限制档使用,可以避免3档和4档间的跳档情况!~(具体它是如何避免的将在下文中做介绍)

2表示2档,此档时,变速箱就在2档上,用于湿滑路面起步,或者慢速前进时作为限制档使用,可避免1和2档以及2和3档间的跳档!~

1就是1档,此档时,变速箱就在一档。这就不用我解释了吧,你就看着情况用吧:)

其他自动档车辆可能出现的档位还有S档、L档(例如本田的飞度等)还有的在变速箱上有个雪花的按键(如别克的赛欧等)、ODOFF按键等。

S表示运动模式(sport)在这个档位下变速箱可以自由换档,但是换档时机会延迟,使发动机在高转速上保持较长时间,使车辆动力加大。当然显然这个会造成油耗增加。

L表示低速档,应该和新雅阁的1,是一个意思,这个档位时变速箱会保持在1档而不升档

第五篇:匀变速直线运动教学设计

《匀变速直线运动的研究》复习课的教学设计海林市高级中学李雪丽

一、课程标准

1、通过史实,初步了解近代实验科学产生的背景,认识实验对物理学发展的推动作用。

2、经历匀变速直线运动的实验研究过程。了解匀变速直线运动的规律,体会实验在发现自然规过程与方法

1. 通过对所学实验的复习,理解小车在砝码拉动下运动的特点及规律,体验物理研究的科学思维方法

2. 通过对匀变速直线运动规律的复习,会分析、解决相关问题

3. 通过对自由落体运动规律的复习,理解其特点、规律,会分析、解决一些实际问题,理解在物理中对一些问题理想化的研究方法

律中的作用。

3、能用公式和图象描述匀变速直线运动,体会数学在研究物理问题中的重要性。

二、教材设计

本章从最简单的匀变速运动开始研究,通过对实验的分析了解关于匀变速运动的规律,从本章的基础性地位同时还体现在方法和能力培养方面,用图像来分析物理问题是高中物理的重要数学方法之一,作为最简单的变速运动,匀变速直线运动的学习将为认识其他更复杂的运动创造了条件。了解匀变速直线运动的规律,才能进一步了解必修2的平抛运动规律;认识匀变速直线运动加速度的特点,才有利于进一步认识匀速圆周运动和简谐运动加速度的特点;掌握了匀变速直线运动位移和时间的关系,通过牛顿第二定律,就能进一步推导出动能定理的关系式。可见,本章的知识在整个力学中具有基础性的地位。

三、教学分析

这节课是对第二章所学习的内容进行总结,一共安排两课时,首先引导学生对本章的主要内容进行复习概括,学生的自行归纳为主,教师的总结为辅。提前布置任务,让学生在课上进行交流,互相补充,争取形成知识网络。同时教师对学生的总结进行点评,最后利用学案的习题进行巩固,使学生能够应用总结出的结论、公式解决具体问题,提高运用所学知识解决具体问题的能力。

四、学情分析

本章学生在已经学习了关于运动的基本概念之后,具备了学习本章新知识的基础,由于学生对匀变速运动的规律还不是很了解,思维方式,解题习惯,计算速度等方面还有很多不同,学习观念、方法还有待改进,对规律的掌握还须加强,公式的掌握的不扎实,甚至有些学生,概念不理解,公式记不准,练习又做的少,导致产生一些学习物理的畏难情绪,教师应及时发现帮助学生走出困境。

五、教学目标及重、难点 知识与技能

1. 会使用打点计时器、会对纸带数据处理和测量瞬时速度、加速度 2.利用匀变速直线运动的规律分析、解决实际问题 3.理解匀变速直线运动的v-t图象,会用图象处理实验数据

4.掌握重力加速度的方向、地球上的不同地方重力加速度大小不同、通常情况下g的取值 5.掌握自由落体运动的特点及规律、会用自由落体运动的特点规律解决实际问题

4.通过对匀变速直线运动v-t图象的复习,培养学生在物理中用图象法解题的思维,认识数学工具在物理解题中的作用 情感、态度与价值观

1. 通过对实验的理解,体验物理研究的科学思维方法 2. 通过作图,培养严谨的科学态度,初步体验到科学的简单美

3. 通过对实际生活中的观察,体验自由落体在生活中的奥妙,体会科学的力量

4. 通过学习伽利略对自由落体运动的研究,培养学生热爱科学、勇于探索、坚持真理的高尚情操 教学重点

匀变速直线运动的规律以及匀变速直线运动的v-t图象 教学难点

具体公式的选择。 教学方法与学习方法

讲练结合、整理、交流和总结

六、教学流程

(一)小组汇报,基本知识点:

1.探究小车的速度随时间变化的规律

实验装置、探究方法、数据处理、实验结论、注意事项 2.匀变速直线运动定义,分类,特点,公式及推导 其他小组,教师补充,学生练习反馈,小结

(二)小组汇报,基本规律整理

3.匀变速直线运动规律:

中间位移瞬时速度中间时刻的瞬时速度连续相等时间内的位移差为定值 初速度为零的匀变速直线运动比例关系 4.自由落体运动

(三)图像应用

(四)小结

(五)作业

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