Who has a grinder exam question and answer!

15

Point, each empty

0.3

Integral)

1

, fill in the form

2

Roll preparation before grinding:

(

Grinding machine idling

)

、

(

Alignment between roller center and grinder center

straight

)

、

(Static balance of grinding wheel

)

three

, I

factory

grind

bed

manufacture

use

about

sand

wheel

rule

style

type

figure

(

750mm * 75mm * 305mm

)

、

(

900mm *100mm * 305mm

) materials (

White corundum

) hardness (moderately soft)

)

、

Granularity (

60

) adhesive (resin

)

four

Maintenance of grinding machine is divided into:

(Daily maintenance

)

、

(

Primary maintenance

)

、

(

Secondary insurance

rise

)

five

The roller materials used in rolling mills and levelers in our factory are as follows:

(

9Cr2Mo

)

、

(

9Cr3Mo

)

、

(

9Cr5Mo

)

six

, CNC roll grinder model

:(

MK84 125*50)

Maximum grinding diameter

(

1250

millimetre

)

center to center spacing

(

5000

millimetre

)

model

:(MK8463*50)

, the maximum grinding diameter (

1250 mm

)

center to center spacing

(

5000 mm

)

seven

The lubricating oil used for the spindle of CNC roller grinder is:

(Low temperature wear resistance

46#

hydraulic oil

)

eight

Cold rolling (roll body

)

、

(roll neck

)

、

(Axle head

) consists of three parts.

nine

、

The role of cooling liquid in roller grinding process (cooling

)

、

(lubrication

)

、

(clean

)

、

(

preservative

) and so on.

Second, the judgment (* * *

15

Scores, every question

1.5

Integral)

1

The spindle of grinding wheel frame of grinder is driven by motor.

V

Drive rotation with a belt.

(√

)

2

The retraction of the grinding machine tailstock sleeve has nothing to do with the rapid advance of the grinding wheel frame.

(×

)

three

After replacing the roller, it should be ground immediately.

Work on the computer immediately after grinding,

So as to increase that cycle frequency of the roller.

(

×

)

four

Grinding rollers should be used in pairs, and the pairing difference between the two rollers should be strictly controlled.

(√

)

five

The diameter and hardness of the roller are within the allowable range, and it is not normal to scrap it because of some defects or even fractures.

Damage.

(

√

)

six

In the process of roller grinding, it is very important to choose the correct grinding wheel, which can not only improve the grinding quality, but also improve the grinding efficiency.

The work efficiency can be improved. When selecting grinding wheel, roll material, heat treatment state, surface roughness and grinding allowance should be considered.

Factors.

(

√

)

seven

Grinding fluid should face the contact line between grinding wheel and workpiece.

First, open the grinding liquid, and then grind it.

Prevent any interruption of grinding fluid;

The grinding fluid should be replaced regularly, and the filter element of the filtration system should also be replaced regularly.

(√

)

eight

The newly bought grinding wheel can be used directly on the machine.

(×

)

nine

The reason why polygonal vibration lines and ripples appear on the surface of grinding roller is that the grinding wheel vibrates relative to the grinding roller during grinding.

(√

)

)

10

、

Adopting reasonable cooling mode and grinding fluid can prevent the defects of roller grinding.

Improve the service life of grinding wheel.

(

√

)

Volume name

Minimum diameter (

millimetre

)

Maximum diameter (

millimetre

)

Length of roll body (

millimetre

)

1250

Mill work roll

300

340

1250

1250

Intermediate roll of rolling mill

360

celebrity

1250

1250

Rolling mill backup roll

1050

1 150

1200

Double flat rolling work roll

3 10

350

1280

Double straightening work roll

4 10

460

1280

Double straightening intermediate roll

440

490

1300

Double flat backup roll

1050

1 150

1200

Third, choose (* * * meter.

15

Scores, every question

three

Integral)

1

、

When the drum is clamped, it should

a

Install a suitable fixture, the center hole is lubricated without damage, and the coaxiality is guaranteed.

a

Clean the center hole;

b

, balance roller;

c

, straightness;

2

If the grinding wheel is obviously blocked or dirty when grinding the roller, the passivated sand particles are not easy to fall off and the grinding wheel is easy to stick to the grinding roller.

If the surface is burned or hairy, choose a grinding wheel.

c

a

It's too hard;

b

, too soft;

c

Coarse grain size;

three

Hardness of grinding wheel on roller

c

The harder the grinding wheel is, the more serious the surface burn of the roller is.

a

, grinding accuracy;

b

And grinding speed;

c

, surface burns;

four

When clamping the grinding wheel, please clean the impurities in the grinding wheel shaft and the cone hole of the grinding wheel chuck to avoid causing

c

a

, the speed is unstable;

b

The surface of the drum is not only;

c

Eccentricity of grinding wheel;

five

When the grinding wheel rotates at high speed, any part of the grinding wheel will be subjected to

a

The magnitude of centrifugal force and the square of the peripheral speed of grinding wheel.

In direct proportion.

a

, centrifugal force

b

centripetal force

c

Cutting force effect

Fourth, short answer (

1-4

Question grinder answers (each question

7.5

Integral)

7- 10

Question assembler answers (each question

7.5

Integral)

five

、

six

、

1 1

The answer to * *

Points, each type of work to write.

)

1

What is the cause of vibration marks on the surface of workpiece when grinding excircle? How to eliminate it?

A:

When grinding, the grinding wheel vibrates relative to the workpiece.

This vibration is caused by the unbalance of grinding wheel,

The grinding wheel drive motor is not stable.

Balance, uneven transmission belt thickness or inconsistent V-belt length. Measures to prevent polygon and vibration are as follows:

①

.

The grinding wheel needs to be carefully balanced (when the grinding wheel needs to be balanced on the balance frame,

eight

Can stay in all directions)

②

.

Motor dynamic balance (recommended

HYQ-22

The whole machine dynamic balance instrument balances the motor and pulley)

③

.

Motor shock absorption (the motor is installed on the machine tool, the lower part should be padded with wood or leather, and the screws should be tightened).

④

.

Reduce belt vibration

⑤

.

Improve the seismic capacity of grinding wheel frame ⑥

.

Select appropriate grinding parameters.

⑦

.

Select the appropriate grinding wheel (pay attention to hardness, particle size and bond type)

⑧

.

Dress the grinding wheel in time after it is dulled, and pay attention to putting the diamond in the right position when dressing.

2

What is the reason for spiral marks on the surface of workpiece when grinding excircle? How to eliminate

A:

Rough repair of grinding wheel is to repair bus unevenness,

When finishing, it can't be corrected because of the small amount of finishing.

Therefore, in precision grinding,

Before ultra-precision grinding, the cutting depth of rough dressing grinding wheel should not be too large.

No cooling liquid is used when dressing the grinding wheel, or the cooling liquid is only aimed at a part of the grinding wheel. Therefore,

When dressing the grinding wheel,

because

Sufficient coolant, nozzle position and coolant should be aligned with the entire width of the grinding wheel.

The main shaft of the grinding wheel rack is inclined or bent,

The cent line of that grinding wheel is not flush with the guide rail of the grin machine on the vertical plane,

Therefore, in the trimming process,

Will make the grinding wheel bus sag. When installing the grinding wheel, the grinding wheel shaft is allowed to tilt slightly, and each

100 mm

about

0.005 mm

, Lord

The levelness of the shaft can be achieved by trimming the guide rail or turntable of the grinding wheel frame.

When the hardness of grinding wheel is uneven in the width direction, spiral will occur.

Formation time,

The grinding wheel should be replaced. When grinding,

The thermal deformation caused by the rotation of the grinding wheel deflects the grinding wheel, leading to the generatrix and rolling of the grinding wheel.

Poor contact between rollers leads to spiral.

Therefore, it is required to correct the grinding wheel and grinding wheel after the machine tool enters the temperature saturation state.

Grinding.

three

What are the types of roll defects?

Answer: Cracking, peeling, scratching, sticking, pulling and breaking.

four

Characteristics of grinding wheel

Answer: Abrasive, granularity, binder, hardness, structure, shape, size and strength.

five

Please write down the type, model and main parameters of the existing grinding machine (

five

Integral)

A:

MK84 125*50

Parameter: Maximum grinding diameter

1250 mm

, minimum grinding diameter

200 mm

, maximum tip distance

5000 mm

Maximum weight of workpiece supporting grinding

25000

Kg, top grinding

5000

Kilogram, grinding wheel specification

Φ

900 *100 * 305mm

MK8463*50

Parameter: Maximum grinding diameter

630 mm

, minimum grinding diameter

90 mm

, maximum tip distance

5000 mm

, the workpiece is the most

heavyweight

6300

kilogram

,

Grinding wheel specification

Φ

750 x 75 x 305 mm

six

, safety operation procedures (

10

)

Safety operation procedures for road roller assemblers:

(1) Before taking up his post, he shall wear complete labor protection, comply with safety regulations and be full of energy.

(2) Ensure that the straddle truck, drum dismounting machine and dismounting platform are clean, and clean up oil stains in time.

(3) It is forbidden to walk across the roller on the dismounting platform to prevent slipping.

(4) Pay attention to anti-skid when disassembling and assembling, and ensure that there are no obstacles in the safe range when disassembling and changing rolls.

⑤ When disassembling the bearing seat,

The driver confirms that the equipment is normal and reminds the assembler to stand firm and hold it well.

Make sure that the bearing seat is in the stop position.

Within the scope of the stable placement, to prevent the bearing seat from falling over.

⑥ Before lifting the drum,

First, check whether the sling is in good condition.

When lifting the drum, two people cooperate and one person directs.

To roll or hang up.

When the roller is stored on the rack, slowly lower the hook.

⑦ When cleaning the bearing seat, confirm whether the bearing seat is placed smoothly, pay attention to anti-skid when cleaning, and clean up the ground oil pollution in time after cleaning.

Safety operation procedure of grinder:

①

Wear complete labor protection before taking up the post, wear and use in line with safety regulations, and be full of energy.

②

Before the grinder works, check the handover record first, and then carry out the trial operation after it is confirmed.

1

—

five

Roll grinding is carried out in minutes.

③

When disassembling and assembling the roller chuck, please handle it carefully to prevent squeezing and squeezing.

④

When the lathe lifts the drum up and down along the grinder,

You have to work with two people,

One-man command,

Confirm the suspension position,

Do it gently.

⑤

Do not wear gloves when operating the grinder, and do not approach the rotating disc. The cuffs, neckline and helmet strap of work clothes must be fastened.

Female workers must put their hair in a helmet to prevent it from being involved in rotating equipment.

⑥

When the grinder grinds normally, the operator shall not leave his post and stand on the tray.

⑦

When grinding the roller, it is forbidden to stand opposite the grinding wheel to prevent the grinding wheel from breaking and hurting people.

⑧

When using manual grinding wheel to guide the angle, you must wear protective glasses to prevent sand from hurting your eyes.

⑨

When checking the surface quality of the roller, the action of the measuring arm must be stopped to prevent extrusion or collision.

⑩

Tools for loading and unloading grinding wheels must meet safety requirements, and substitution is prohibited. When replacing grinding wheels, it is forbidden to use defective grinding wheels.

Grinding wheel, and use special tools, two people cooperate to remove.

When the grinding wheel rotates, it is forbidden to open the safety cover to clean the grinding mud of the grinding wheel nozzle.

When replacing the support tile, the oil stain on the site must be cleaned in time to prevent slipping, falling and squeezing.

seven

Static balance method of grinding wheel.

answer

& lt 1 & gt；

Adjust the balance surface composed of two cylinders of the grinding wheel balance frame to the vertical and horizontal positions.

& lt2 & gt

Remove all the balance weights, insert the balance shaft into the flange hole, put it on the balance frame and roll slowly until it comes to a standstill, and do it at the lowest point of the grinding wheel.

Mark, this mark is the center of gravity.

& lt3 & gt

Relative to the center of gravity

180

Tighten the first counterweight gently. This counterweight is advised not to move in the future.

& lt4 & gt

The other two counterweights are symmetrically fixed to the counterweights.