Definition

The constraining barrel of the device is operated by hydraulic technique to compress steel sheets. The left and right oil barrel control the blade upwards and downwards motion.

Sheet shearing devices are of two kinds: hydraulic and automated.

Automated kinds consume too much energy and produce clamor, that is why shearing type have got wider use. In terms of knife movement, hydraulic shearing devices fall into two categories: hydraulic rotation shaft and guillotine shears.

Hydraulic Shears and Mechanical Shears

Varieties of Shearing Devices

Guillotine and sheet shears

The shearing device knife operates through a straight movement interchanging with other knives to cut plate metals.

Manual guillotine and sheet shears

These devices are operated manually.

Hydraulic guillotine and hydraulic sheet shears

These are operated by hydraulic technique.

Axle knife and rotation shaft shears 

The top knife holder rotates around the axle.

Hydraulic axle knife and hydraulic rotation shaft shears

These devices are operated by hydraulic technique

Multi-bar cutter and scroll cutting shears

These machines realize cutting scrolls through scissors into numerous bars according to any breadth.

Multi-lane cutter and plate cutting shears

Cuts sheets through scissors into numerous lanes according to any breadth.

Pecking shears

Used to gain required shapes little by little

Circular and rotating devices

This device has got rotating knifes for cutting sheets either in a direct or crooked lane.

Multi-function iron worker intended for perforation, as well as strip or charter shears

These devices are intended for perforation and shearing

Multi-function iron worker to cut sheets and charters

The device realizes metal sheet perforation and shearing

Multi-function iron worker for perforation, sheet, strip and charter shears

Equipment suitable for sheet perforation, sheet and charter cutting

Multi-function iron worker realizing punching, strip or charter shearing and grooving

This device realizes four operations mentioned above.

Ingot and charter steel shears

Realize steel charter cutting

Bar shearing device

Intended to shear bar stuff

Alligator shearing machine

The top knife of this machine acts in scissor movement.

Fortifying bar cutter

Possesses special function to reinforce bars.

Exact bar shearing machine 

Intended for precision bar cutting

Slab shearing machine

Suitable for slab shearing

Slice shears 

Intended to shear slice steel.

Billet shears

Realize ingot shearing.

Basic Structure and functioning of Hydraulic Shearing Machines

Frame of shears

1. The shell is brazed out of steel, which consists of left side and right side boards, a worktop, a clip carrier and oil tank. There is a hydraulic barrel and gliding unit manual stand on either parts of the frame. It is a press-up appliance managing blade gaps.

The press-down barrel upon the clip carrier keeps sheets pressed to shear.

2. Blade carrier

Stationary top blade together with barrel move upwards and downwards, produce shear enforcement and realize shearing. Back gauge appliance stands on the blade carrier as well to adjust sheet sizes.

3. Cutting blades

These are made out of top quality steel and are able to shear stainless steels as well as steels of low carbon.

4. Back gauge appliance

This is set upon the blade carrier and consists of operating engine, mini-dynamic regulating apparatus, a back gauge raising unit, a display a gearbox pin and a manual zone.

The engine operates back gauge motion as well as the cease plate for lengthy cutting.

5. Oil tank

This is set at the back of the shear. The hydraulic combined faucet unit, pump and basic engine are on the left. This part also includes fuel mold, which needs to be just half filled.

6. Gap regulation unit

Proper up and low blade clearance ensures the required force in shearing process. Besides, this makes the serve life of blades longer and produces high quality. In general, the gap between blades should be 10% of the sheet density.

7. The head mainstay

 This supportive unit is fixed upon the worktop and is intended to make shearing sheet vertical to both parts.

8. Finger defense bar

It is set on the clip carrier of the shearing device and is designed to manage secure space for fingers. To achieve safety the defending bar location should be adjusted according to the automated secure standards.

Safe distance for fingers protection
Shearsmax. Amin. B
8/6.5/30001280
8/6/40001280
10/3000/400020120
13/300023200

1. While setting a sheet in the back cease unit, avoid putting fingers between the sheet and worktop.

2. If the back gauge unit is out of its location, do not press the sheet with finger secure bar to avoid finger scrape.

9. Press-down barrel

This is intended to keep the sheet fixed in shearing process.

10. Electric technique of shearing device 

Operation of this technique implies starting and running fuel pump engine to produce the required enforcement for shearing. The managing framework operates the faucet and fuel pressure according to management regulations to put the blade carrier into action for shearing.

Meanwhile, it regulates blade impact, motion backwards and forwards, enlightening of aligning bar, gap size and bevel adjustment.

11. Hydraulic mode of shearing device

This includes fuel pump, hydraulic framework and barrel, pressure barrel, hydraulic tube. The fuel pump ensures cutting pressure. Hydraulic framework manages the framework pressure and fuel flow course. The hydraulic barrel is applied to run blade carrier motion. The press-down barrel keeps the sheet fixed to provide precise cutting.

Operation of Hydraulic Shearing Machine

1. Preparing before function

Swipe the fuel from the face of device parts. Mind that the faucet is open.

Anoint the necessary parts.

Load the tank with N32-N46 dense fuel (in filtered condition). 

Turn on the electricity deliver system.

Prior to operating see about the ball knob condition.

2. Shearing machine functioning

1. Run the device for several circles.

2. While cutting unveil the pressure gauge and note the fuel pressure. If any abnormality, make the required faucet flow settings.

3. Regulate gap between blades appropriate to sheet density.

4. Place the sheet on the worktop.

5. Regulate the back gauge in accordance with plate size.

6. Press the sheet to put it into touch with the back gauge sheet and adjust shearing size.

7. Press the foot button to realize shearing.

8. Do it again 4-6 times to shear the next plate.

9. After shearing process, pass to the working out process.

10. Switch off the device after operation and maintain it daily.

Secure rules

The shear worker should master the unit framework and functioning.

The worker should know the usage and maintaining norms.

Anoint the proper points, mind the fuel amount and properties. Shut the fuel cup.

Correct blades before functioning. Blade slit needs to be regulated sheet density demands. In general 5-7% of the sheet density. Set blade slit by rotating the fly wheel and mind it through sensitive gauge.

Weaken the anchor screw appropriate to the work piece, regulate the fixing plate then tighten it. Operate the device from two to three times prior to work.

Avoid harsh actions while weakening the back gauge unit or regulating the gap between knives. Before regulating the gap, switch off the device.

Blades always need sharpness. So if required, they must be substituted.

The clip spring pressure together with gap have to be regulated as required to prevent the spring crash and damaging knife ridges.

Avoid cutting steel bars and mind that while cutting random objects do not appear on the worktop to keep them from getting into blades.

Mind proper clipping and fixing. Stop running the device if any problem.

After operation switch off the power supply, clean the device.

It is not advisable to shear too long and dense sheets, steel requiring top velocity and mold iron.

Start the engine with unloaded device. Make proper checking before starting operation.

Explosive items, too thin work pieces and stuff of non-metal type are forbidden to cut.

Keep hands and fingers away from blades. Having two operating workers meanwhile is forbidden. No one should stand at the back of the device.   

Note these tips

1. Often mind the blade slit and regulate it appropriate to sheet density.

2. Knives must always be in proper condition, the cutting face must have no scratches.

3. Cease operation while making necessary regulations.

4. The utmost heat of the tank should not surpass 60 degrees.

5. Avoid cutting slim bars. The narrowest cut stuff should be at least of 40 mm.

6. If hydraulic shear allows cutting sheets with utmost density of 16 mm, the density of Q345 sheet is 13 mm, 8 mm. For Q235 sheet and 6 mm for Q345 steel sheet.

Blade stuff of hydraulic shears

Average blade solidity

6.5/10mmHRC58/59
13/16mmHRC56/57

These types of knives are able to shear rolling sheet and steel sheets. In case of shearing solid stuff knives with 56/57 HRC solidity are suitable.

See also 8 Widely Applied Materials for Hydraulic Shearing Blades.

Regulation of blade bevel

Estimating clearance and knife bevel is dependent on the sheet. Gas case bears a chart for regulating the necessary records. For instance, increased lean bevel decreases the shearing ridge. Though it might also bring to deformity if a strip is being cut. Occasionally, decreasing the lean bevel might decrease deformity.

The least cutting breadth for hydraulic shearing machines

It has to be triple as dense as the sheet with no required shear precision. Otherwise, plate breadth should be six times as thick as the sheet while bending. If cutting sheet is wider, the deformity will be smaller.

 Shearing precision

The records of shearing rolling sheet of 2 mm are:

While adjusting x=100 mm, the sample parallelism limit is 0.15 mm and the directness is 0.25 mm in every 1000 mm.

The recurring set precision of X axles is 0,02 mm.

Shear device blade adjustment

Top blade installment

Raise the blade, fix M12*40 bolt on the top blade. Avoid tightening bolts at both ends meanwhile. Hold the top blade by a rod. Screw M12*40 bolt while the top blade face is contracted to the glider face. Bring downwards the glider, turn off the pump engine, then fix M12*40 bolt on blade tips. The bolt torque should be 35 N/M.

Bottom blade installment

Start the fuel pump, raise the glider until it gets fixed, when the fuel pump is off, install the knife and fix the hexagon bolt M12*45. Push the blade by a rod to set it closer to the worktop base and bolt the M12*45 screw as required.

Blade slit regulation

1. Excessively little gap

In general, the average blade slit is 0.02 mm and this is the same density of A4 format paper. Cutting paper with shearing device is a widely applied mode to regulate blade slit.

If blade gap is too little:

The blade ridge appears under an excess enforcement, and this will result in the blade distortion.

The top and bottom blade disturbance brings about blade fracture and is dangerous for the worker.

2. Excessively large blade gap

If so, the these troubles are possible;

The plate size is not imprecise. Many bumps appear on ridges.

The sheet gets clutched and becomes hard to remove it. This may bring on the cease of functioning. But this is not the case if a dense sheet is cut.

After long work blade clearance has to be regulated. On average the recommended gap is 10 % of sheet density. The bottom blade determines proper gap, as it is stuck on the device, the top knife regulating in accordance with it. The least gap must be 0.05-0.1 mm. Weaken the locking knob at the regulation handle base, rotate the regulation handle till the same gap on both blades. If the gap of the down blade has no correspondence with proper demands, set allen bolt M16*60 and M12*65 to leave 0.05 mm gap. To achieve perfect gap M12*65 and M16*60 hexagon bolt should be regulated from time to time.

Operation principles of Hydraulic Shearing Machine

Shearing metals is done by the motion of top and bottom knives, functioned by hydraulic technique. Mind Hydraulic Guillotine Shears vs Swing Shaft Shears to gain a complete understanding of  hydraulic technique.

Required care 

Realize machine care continuously, which implies anointment, cleaning fuel tank as well as the whole device.  

1. Secure tips.

Realizing maintenance it is advisable to switch off the device.

Prior to removing the faucet switch off the pump. Bring down the glider to the fuel barrel with no fuel. If any failure to do this, pad by a log and note the pressure.

2. Anointment of shearing device parts

Anoint the device once a week. Calcium base oil is the most suitable and it must be instilled into every proper point. Anointment points can be seen beneath:

Anointment points are ball bolt, clutch and screw holder, glide path and base, gliding guide path and gap regulating bolt and clutch.

3. Hydraulic oil and calcium base oil

These types of hydraulic oil are the advisable: NUTO H46, TELLUS 46, HARMONY 46 AW, HLP46, RANDO OIL 46, MOBIL DTE 25.

No.Lubrication PointGrease
1Ball screw, nut and screw and bearingCalcium base greace
2Guide rail and slide guide base Calcium base greace
3Sliding block guide rail Calcium base greace
4Guide rail and clearance adjustment screw and nut Calcium base greace

4. Oil changing

It needs changing after 2000-hour function for the first time, then change it once 2 years or 4000 hours of operation.

Before taking off the tank lid, wipe the around setting to avoid impurity. Wipe the inner side with cloth and resolvent. Change the filters. Fill fresh fuel. Before functionning the unit let the pump to work up to 60 minutes.

5. Maintenence manipulation

These data are correct in case of eight-hour working day.

Machine part Spots requiring care Interval
Whole framework Clean the device and anoint the knives Every week
Slider Gun anointment Every week
Back gauge holder Gun anointment Every week
Back gauge ball bolt Gun anointment Every week
Slider pathNote the deepness regulation Once within three months
Mind back gauge location If it surpasses 0.1 mm, then set it again Three months
Hydraulic details Pay attention to fuel quantity. In case of replacing new fuel, insert fresh filter. Every week
Hydraulic details Empty old fuel and add new. After twelve months
Hydraulic details Make necessary checking to avoid leak and obstruction. Three months
Foot switch Note its normal state. Every motnh
Power management unit Mind the switches in the power block. In case of outwear make replacement. Three times
Finger defender Mind its normal condition to avoid physical harms. Every motnh

Swing shaft shearing devices are generally called QC12K/Y, guillotine shearing ones QCK/Y.

Design of hydraulic shears

1. Glider motion upwards and downwards

Fuel flows in S6B through S6P, uncover S8 faucet to let the fuel flow into the bottom part of right side barrel, let the fuel flow from the right side tank in the down bottom of the left barrel. So fuel of the left side barrier top ward flows into S6A and S6T making glide raise.

If S6Y1 gets power, the fuel runs to S6A through S6, later to the top ward of the left side barrel and the top ward of the right side barrel. The fuel runs from S7 to S6T through S6B and returns fuel tank making glider lower.

2. Bevel regulation 

If no data is put in the shearing bevel of the device, the gliding unit is not able to move up or downwards. Regulate shear bevels like this:

After getting power the fuel from S2 and Y2A, flows into S2B through S2P, unlock hydraulic one way faucet S3, flows into left side barrel bottom ward and top ward of the right side barrel. As the left side barrel top ward is not able to circulate, the left fuel barrel remains fixed. When the right side barrel bottom barrel fuel returns to tank through S6T, S7 and S6B faucet, the shearing bevel shrinks.

On the other hand, if Y2B gets power, fuel runs into S2A through S2P, uncover one way S4 faucet and into the right side barrel bottom ward. The right side cylinder top ward fuel enters only one way faucet S3, then S2T through S2B causing cutting bevel to expand.

The relationship between shear angle and shear force:

Mild Steel (mm)681013131313161620
Stainless Steel (mm)3468888101012
Shear Force (KN)1322204307306206206507308501270
Shear Angle Adjustment0.5-2.5 0.5-2.5 0.5-2 0.5-2 0.5-2.5 0.5-2.5 0.5-2 0.5-3 0.5-2.5 0.5-3

3. Press down barrel operation

When S9 gets power, the fuel flows in S9A through S9P, later comes to the top ward of clipping unit, holds the cylinder downwards forming pressing. When S9 does not receive power, clipping cylinder springs up, causing the fuel in top ward of clipping piston flow into S9T through S9 faucet.

Design of hydraulic shear framework

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