Operation and adjustment of the guillotine shear

Preparation before running #

a. Be familiar with the contents of the manual, and understand the main structure, operation method and safety maintenance precautions of the machine.
b. Clean the antirust oil on the surface of the machine. It is allowed to clean it with gasoline and kerosene. It is not allowed to clean it with dissolving detergent.
c. Clean the oil tank before refueling. No impurities are allowed in the oil tank. During refueling, unscrew the nut of the air filter on the oil tank cover plate and inject filtered new oil Yb (c) – N32 or Yb (c) – N46 hydraulic oil (the filtering accuracy of the fuel dispenser shall not be less than 5 μm) Until the oil level reaches more than four fifths of the position indicated by the level gauge. After repeated tests, Mobil AFT-25 hydraulic oil has the best effect; At low temperature (about 5 ℃) in winter, YB-N32 anti-wear hydraulic oil is recommended. The machine tool must be idled for a period of time. If necessary, a heater can be installed in the hydraulic system. The oil temperature of the hydraulic system under normal operation shall not exceed 75 ℃. If the oil temperature is too high, a cooler shall be installed.
d. Add lubricating grease at all moving parts according to this manual;
e. Turn on the power supply, turn the switch of the electric cabinet to the “1” position, do not start the oil pump motor, and check whether the hydraulic valves and relevant electrical components operate normally according to various process specifications and operation modes.

Machine operation #

1) Press the motor start button to start the main motor, check whether the rotation direction of the motor is consistent with the rotation direction on the oil pump label, and you can know the rotation direction of the motor by watching the coupling. If not, stop immediately. When changing the motor direction, professionals must cut off the power supply and change the incoming line phase. When there is air in the pipeline system, press the start button and stop button alternately for several times. After the air is discharged, the oil pump can enter normal operation.
2) The detailed operation of new product programming must be carried out after reading the electrical system operation manual and operation manual in detail.

Machine adjustment #

The machine tool has been accurately adjusted and tested before leaving the factory. All adjustments may change during transportation.

The following checks must be made before formal use.

1) Adjustment of blade clearance: #

The blade clearance of the machine is automatically adjusted by the numerical control system.

Whether the blade clearance is adjusted properly will directly affect the shear quality of sheet metal and the service life of blade.

In order to obtain high-quality cutting end face, a reasonable blade gap must be selected according to the material to be cut.

The following methods are recommended to adjust the blade clearance.

Based on tensile strength σ B = 370-400mpa, elongation δ= 35% low carbon steel is used as the adjustment benchmark, and the blade clearance is selected according to 8% of the plate thickness.

For medium and high carbon steel with low elongation, the blade clearance value shall be greater than that of low carbon steel with equal thickness.

When shearing stainless steel plate, the blade clearance depends on its elongation, and the blade for shearing stainless steel shall be used, because the elongation of some stainless steel is higher than that of high carbon steel with the same strength.

Attention:
a) After the blade clearance is adjusted, the machine must run empty at least once before formal shearing.
b) When shearing plastic materials, the blade clearance should be slightly smaller; When shearing brittle materials, the blade gap should be slightly larger.
c) After adjusting the blade clearance every time, trial cutting must be carried out.

2) Adjustment of shear angle: #

The shearing angle of the machine is automatically adjusted by the numerical control system.

By adjusting the amount of oil in the upper chamber of the auxiliary oil cylinder, the shear angle can be changed.

When the shear angle is increased, the workpiece is easy to deform, and when the shear angle is reduced, the workpiece is easy to produce burrs.

Attention:
a) After adjusting the shearing angle each time, the machine must run empty at least once before formal shearing.
b) When the cutting requirements are not high, the minimum width of the narrow material that can be cut shall not be less than 3 times of the plate thickness, otherwise the blade is easy to be damaged.
c) In order to obtain smooth shear parts without distortion and deformation, the minimum shear plate width shall be greater than 15 times the plate thickness, but not less than 80mm.
d) The larger the width of the shear sheet, the smaller the deformation.

3) Removal and installation of blade #

The standard configuration of the upper and lower blades of the machine is two pieces of knife splicing, which has the advantage of convenient grinding and does not need a special grinder.

According to the needs of users, the whole length of upper and lower blades can be configured.

a) Blade removal

Start the machine, adjust the blade clearance to the maximum value of 0.64mm, adjust the shear angle to 1.0 °, make the tool holder run up and down for several cycles, close the machine tool, and remove the protective fence and cover plate of the pressing cylinder.

Remove the lower blade first:

loosen all the mounting screws of the two lower blades, hold a lower blade with a long wooden square at the back of the machine tool to prevent the lower blade from overturning backward, remove the screws on the blade, and pull out the blade at the side of the machine tool.

Remove the other blade in the same way.

Then remove the upper blade:

loosen all the mounting screws of the two upper blades, pad two suitable wooden squares between one upper blade and the workbench, and tighten the upper blade, remove the screws on the blade, slowly loosen the wooden squares, and pull out the upper blade on the side of the machine tool.

Remove the other upper blade in the same way.

b) Blade installation

The order of installing the blade is the reverse of the order of removing the blade.

Install the upper blade first:

insert two suitable wooden squares at one end between the tool holder and the workbench, insert an upper blade from that end, hold it with two wooden squares, install the screws on the blade without tightening, and then install another upper blade in the same way.

Use these two wooden squares to press an upper blade upward to make the upper blade fully close to the blade edge fitting surface of the tool holder, and then tighten the screws on the blade from the knife joint to the edge in turn. Tighten the screws of the blade on the other blade in the same way.

Then install the lower blade:

insert two lower blades from both sides of the machine, and hold the lower blade with a long wooden square at the back of the machine tool.

First install all screws, and then tighten the screws of the lower blade from the knife joint to both ends in turn.

After the upper and lower blades are installed, install the cover plate and protective fence in turn.

Attention:
a) When removing the blade, the blade is heavy and sharp. The operator must be very careful and wear gloves before operation.
b) The tightening force of blade screw is 35N · M.

4) Blade grinding #

The blade must be grinded regularly.

After the blade is cut blunt, if it continues to be used, the outer grain structure of the blade will be damaged due to excessive pressure, which will not only damage the machine but also get good shear quality.

After grinding the blade, the grains in the outer layer can be removed.

There are four cutting edges for the upper and lower blades of the machine. When the fillet radius of the blade is greater than 0.25mm, grinding is required.

The amount of one-sided grinding is 0.5mm, and the grinding allowance of each blade is 4mm (2mm on one-sided).

If the blade grinding of the normally used plate shears is arranged according to this method, the grinding amount will be the smallest and the service life will be the longest.

5) Adjustment of blade clearance uniformity #

After the blade is grinded or changed, the blade clearance uniformity must be rechecked and adjusted as follows:

a) Start the machine tool, adjust the shear angle to 0 °, make the upper and lower blades parallel, and adjust the blade clearance to the maximum value of 0.64mm.

b) Turn off the oil pump and manually adjust the throttle valve 120 to make the tool holder move down slowly until the upper and lower blades coincide for 1-2mm on the whole length, that is, close the throttle valve to ensure that the tool holder does not slide down.

Valve stack layout

c) Open the electrical cabinet door, press and hold the AC contactor 1KM2 that reduces the blade gap, monitor the actual value of the blade gap through the handwheel page, adjust the gap between the upper and lower blades to a minimum of 0.08mm, and close the electrical cabinet door.

d) Loosen the thrust screws and nuts on the two disc spring supports, loosen the nuts on the four spacer adjusting screws at the rear, and adjust the four adjusting screws to make the distance from both ends of the upper blade to both ends of the lower blade consistent (when adjusting one end, the upper and lower adjusting screws need to be adjusted at the same time).

Measure with a feeler gauge, the gap is 0.05 mm and 0.1mm.

Then tighten the nuts on the four adjusting screws and the thrust screws and nuts on the two disc spring supports.

Structural drawing of tool rest guide rail

e) Adjust the adjusting screw on the tool holder from left to right, and check the edge clearance with 0.05mm and 0.1mm feeler gauge to make the 0.05mm feeler gauge pass, but the 0.1mm feeler gauge cannot pass.

f) After shutdown, restart the machine, adjust the shear angle to the maximum, then close the oil pump, adjust the throttle valve 120 to make the tool holder lower slowly, and check whether the blade clearance of each section is the same as the originally set clearance value of the system.

If not, you can continue to loosen the four adjusting screws on the rear side and adjust the blade clearance to the same value as the originally set clearance of the system.

g) Re-tighten the locking sleeve on the potentiometer and adjust the position of the gap adjustment travel switch.

6) Adjustment of rear stopper #

Rear stopper

a) Angle adjustment

The angle of the rear retaining positioning surface must be consistent with the running angle of the tool holder, otherwise when the shear angle changes, the rear stop positioning surface will change and the rear stop positioning will be inaccurate.

When checking the angle of the rear stop locating surface, place a dial indicator on the wallboards on both sides of the machine, and point the head on the locating surface.

When the tool holder goes down, the reading change of the dial indicator shall not be greater than 0.05mm. If it is greater than 0.05mm, adjust the screw M8 × 30 (GB70-85) and screw M8 × 35（GB85-88）。

b) Parallelism adjustment

Loosen the lock nut, turn the adjusting screw, measure the distance from both ends of the rear stop locating surface to the lower knife edge with a depth ruler, and then tighten the lock nut after the error does not exceed 0.05mm.

Try to cut the plate and check the parallelism. If there is any deviation, continue to adjust.

The distance from the middle of the rear retaining locating surface to the lower knife edge shall be slightly larger than that at both ends.

If the distance deviation from both ends of the rear stop locating surface to the lower knife edge is too large, loosen the screws supporting the transition plate connecting the servo motor, and then loosen the connecting screws between the support and the transition plate, so that the synchronous toothed belt can be loosened, and then rotate the ball screw on one side to make the distance from both ends of the rear stop locating surface to the lower knife edge almost the same, and then install the synchronous toothed belt, tighten the connecting screws and tighten the synchronous toothed belt.

Then adjust the parallelism, and the adjustment method is the same as above.

7) Pressure adjustment of hydraulic system: #

The pressure values of the machine tool have been set according to the working specifications before leaving the factory.

The user does not need to adjust by himself, but after the machine is overhauled or the hydraulic components are replaced, if the user really needs to adjust the system pressure by himself, valve 30 shall be adjusted according to the maximum working pressure (25MPa) of the hydraulic system.