Mechanical parts problems, what is the failure of mechanical parts

The ratio of the height of the cushion block to the length of the fulcrum under the product to the length of the cushion block is the angle tangent.

That is, the height of the cushion block h=tga*l a is the angle value. l is the distance between the two fulcrums of the product (if the product is placed diagonally, there must be two fulcrums, one of which is the position of the cushion).

TG30°=,TG45°=1,TG60°=,Screw tapping drilling diameter.

Metric Thick Thread American Thick Thread.

Specifications Standard Diameter Grade 2 Dental Drill Diameter Specification (UNC) Standard Diameter Grade 2 Dental Drill Diameter Maximum Minimum Maximum Small.

no8-32(

m10× 2-4-1/2

m11×m12×

m14×m16×

m18×m20×

m22×m24×

m27×m30×

It seems that you are indeed a newbie, and the questions you ask are very basic.

What I can tell you is 1, about the angle, it is indeed related to trigonometric functions, if you don't understand, go to high school math, 2 Whether it is metric ribs or imperial ribs, as well as American ribs are all standard checkable, which means that the standard has specified how big the bottom hole is, how much pitch and so on. But you'll have to look it up for yourself, because it's all about your profession. 3.

If you have time, read more basic books on mechanics, because there is too much knowledge in this industry.

The first one is to look up the trigonometric function directly, which is very simple, and the upstairs is very clear......As for the imperial system, one inch is equal to 1 4 if it is", just use it directly, that is, the thread warp, and you can estimate it yourself and almost know how big the hole is drilled......

1.What kind of grinding do you use, the grinder has a horizontal and longitudinal feed, and you can set the feed.

2.Metric thread type 45 degrees, easy to calculate, inch thread has 60 degrees, there are 55 degrees, check the standard respectively.

GB 12716 GB 7307, the standard is very detailed, and it is not clear here.

Concept: All kinds of parts or components in mechanical equipment have certain functions, such as transmitting motion, force or energy, achieving prescribed actions, maintaining certain geometric shapes, and so on. When a mechanical part loses its originally specified function under the action of load (including mechanical load, thermal load, corrosion and comprehensive load, etc.), it is called failure.

A part is considered to be in one of the following three states: it is completely inoperable; Failure to complete the prescribed functions according to the established specifications; It cannot be used reliably and safely. These three conditions can be used as the judgment principle of whether the mechanism fails or not.

Failure hazards: The failure of mechanical parts and components will eventually lead to the failure of mechanical equipment. The failure of key components can cause equipment accidents, personal accidents, and even catastrophic consequences on a large scale. A small part failure on a production line can paralyze the entire production line.

Therefore, it is of great significance to effectively prevent, control and monitor the failure of parts.

Failure of mechanical parts, this should refer to the failure of a certain kind of mechanical parts, for example, which are easy to deform and are not stored in accordance with the formal requirements, and are stored for too long, etc., resulting in the parts can not continue to be used, which is failure.

1. When the mechanical parts cannot work normally and lose their functions, they become invalid.

2. There are several types of failure modes:

Parts break. Excessive permanent plastic deformation of the part.

Surface damage to parts due to corrosion, wear, or fatigue.

Failure caused by disruption of normal operating conditions.

How to remove the gate riser of iron castings in general ()a knock off.

Normalizing is cooled in air (page 8).

On the cutting shaft 1:20 taper, small diameter d = 30mm, length l = 200mm, quantity = 10 pieces, what method to apply to process b transfer small slide plate method.

In addition to the 8 kinds of surfaces processed by general lathes, except for circles, end faces, holes, threads, and grooving, there are the following three kinds of B cone surface, knurled and curved rotary surface.

When marking the blank with a round hole, how to deal with this hole c hit the hole plug to find the center of the circle.

What kind of saw blade should be used for sawing medium-thickness workpieces.

In order to increase the clamping force of the vice, a long steel pipe is sleeved at the handle, is this operation correct? b incorrect.

What is a threaded tool? What threads is it used for? () C tap, internal thread, D die, external thread.

Judgment is right or wrong) in the gating system, the function of the sprue is to ensure that the filling pressure is right.

Judgment is right or wrong) investment casting shell has a maximum of two parting surface errors.

The most ideal and commonly used welding position in production is flat welding. Right.

Judgment is right or wrong) The reason why acid electrodes are widely used is that the weld has good crack resistance.

Judging whether it is right or wrong) The feed movement transmission route of the general lathe is: spindle - exchange gear - feed box - smooth bar or lead screw - slide box - tool holder pair.

The processing time is t hours.

Then 30t-(30-10)t=40 (the master processes 40 more than the apprentice) to get t=4 hours.

30t+(30-10)t=200pcs.

The number of processing units of the master + the number of apprentices processing = the total number of parts.

1、c 2、c

Here's my reasoning:

Question 1: As shown in the figure below, Figure 1 shows the loose edge on the top and Figure 2 shows the loose edge on the bottom. 1, 2 are small pulley, large pulley of the wrapping angle, from the figure can be seen, loose edge on the time, 1> 3, 2> 4, the wrapping angle is large friction, is conducive to transmission.

<> Question 2: When the tensioner is on the outside of the loose edge and close to the small pulley, the curvature of the V-shaped belt becomes smaller in the small pulley, and the curvature is reversed after reaching the tensioner, and so on, which is equivalent to continuous bending up and down for the V-belt, and the bending stress is constantly changing, resulting in the reduction of life.

This is the knowledge I learned when I learned mechanical design with Bu Lian, [it took a long time to draw], [hope]! Thank you!!!

b Make installation easy.

d. The tensioner is on the inside of the tight edge and close to the small pulley to ask the master to answer.

When the V-belt drive is installed horizontally, the way in which the V-belt life is shortest is, D

As far as employment is concerned, there is almost no difference between the two professional names.

As for the employment prospects, the mechanical major, or the mechatronics and other majors are relatively easy to find and difficult to find, the good thing is that this major has a wide range, and all walks of life have suitable positions for this major, which can be said to be a "panacea" major. The difficulty is that there are many mechanical graduates, and it is difficult to find a job with a satisfactory income, unless your school is a top school in China.

There is basically no difference, they are mainly based on machinery manufacturing, supplemented by electrical automation control courses, in the early years, they were more professional, but now they are not good, employers need compound talents, so the colleges and universities are combined to teach courses.

In terms of employment prospects, machinery manufacturing is extensive, and the machinery industry needs technical personnel.

But in fact, there are a few people who really eat this meal, and most of them are engaged in management, sales and other industries after employment.

Don't research which one is better, as a person who has come over, it is the right thing to see which school has more job opportunities. The South is better than the North, and the big cities are better than the small ones.

The development direction of mechanical assembly is assemblers, maintenance workers or something. The development direction of mechanical manufacturing is mostly in terms of design, engineers or something. The employment prospects are different, and it depends on the depth of your studies, the opportunities to find a job, and so on.

Machinery and equipment itself is a big field, some professional information can be seen in the college column of Wanji.com.

The difference is not too big, it is mainly based on your own interests!

Normally, most students in society have nothing to do with their majors and real jobs! I originally studied numerical control, and then I learned mechatronics, but my current job has nothing to do with my major! That's the way it is, theory and practice are very different, it depends on how you look at it, learn to be a person and then learn to do things, believe in yourself, you can! Come on.