Sheet Shearing Machine
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Sheet shearing machines
shearing has always been known as one of the oldest processes in metalworking. In the manufacturing industries, the use of cutting machines is usually the first process in production. Different shearing machines should be selected based on the required shearing capacity. The quality and efficiency of all shearing machines are rated in terms of their ability to cut steel. shearing a steel sheet or plate is very similar to the function of scissors to cut a piece of paper. In a guillotine sheet shearing machine, the two upper and lower blades are placed side by side at a short distance and gently approach each other during operation.The lower blade is always fixed into the bed of machine and the upper blade can move up and down straight or at an angle.The thicker and harder the workpiece, the gap between the blades or the upper blade angle can be increased to reduce the tonnage required for shearing . A high quality cut saves time for subsequent processes such as bending and welding to begin faster, so to ensure a quality, clean cut is so important.
- Main frame
- Bed
- Squaring arm
- Hold downs
- Blades
- Gaging
- Control
- Accessories
The main frame of the machine supports all the components of the machine such as the lower bed and the drive system. A quality shear has a heavy and hard frame that helps the machine to cut materials with different sizes. Some light shears are prone to breake in the side panels, cracking of the bottom plate or warping of the ram, which are rooted in poor design of the device.
The bed is what your operator performs the shearing operation on it. the bed supports not only the workpiece but also the lower blade. The bed of high quality shears should be heavy and strong so that the operator does not have trouble placing his hands under the metal sheets in order to lift, move and control them. Also, for shears with higher capacity, some balls are usually used to transfer and place the workpiece into shearing spot.
The squaring arm is so crucial because it gives us a 90 degree accurate cut and minimizes shearing angle errors. This squaring arm can be equipped with a measuring scale that is mounted on the front of the machine.This measuring device eliminates the need for a separate measuring gauge at the back of the device. Usually the length of the squaring arm is equal to the length of the upper blade, but you can use the arm with different lengths according to the different purposes of working with the machine.
Hold downs are clamps that are close to the shearing blades. The function of these clamps is to hold the piece steady in order to prevent it from moving during the shearing operation.
Shearing blades are usually steel tools that are hardened to withstand abrasion. The gap between the upper and lower blades is usually a few thousandths of an inch.The upper and lower blades can be replaced with each other. It is also possible to replace the blades with a new blade or sharpen them again. shear blades usually have 2 or 4 sharp sides , which are used depending on the design of the machine.
Currently, 95% of the machines on the market have a measuring system. precise measurement not only helps cut accuracy but also speeds up the operator. These gauges are usually located behind the shearing blades in the machine and are computer controlled.
A shearing controller can be a hand wheel that manually connects the back of the machine to a pedal. This controller can also be a programmable computer system that has a more accurate operation than the manual mode.
By providing some optional accessories for the shearing machine, it can be prepared to meet different needs. This leads to an increase in speed, simplicity, accuracy and reliability of the cut.
Some of the accessories of sheet shearing machines are:
- Hydraulic cooling systems
- Workpiece transfer systems
- Manual cuts
- Gage in front of the machine
- High speed cuts (for hydraulic types only)
- The front cover of the machine
- Foot pedal with emergency stop button
Types of shears:
GuillotineThe guillotine design in a shear refers to the movement of the upper blades. The upper blade is moved directly and without angle by a mechanism. These types of shears usually have a larger and heavier design and are almost always found in designs with a capacity of 1/2″ or more.
Swing beamThis type of shears has been commonly designed to use the force of the lever by the ram to increase the tonnage and shearing capacity of the machine, then the upper blade is guided down by a mechanical or hydraulic action by the force of the lever. These types of shears are usually designed with a lower height. The blades of these shears usually have 2 sharp edges, while in guillotine shears all 4 edges are involved in cutting. Modified versions of these shears are also available, which are very popular these days.
Types of shear drive systems:
Hydraulic: Hydraulic pressure is applied to the ram by one or more cylinders and move the ram and the upper blade downwards. Hydraulic machines usually use one or two hydraulic cylinders for shearing operations.
Mechanical: The motor spins a large anchor wheel at high speed and then operator engages the clutch, which can be pneumatic, hydraulic or mechanical. When the clutch is engaged, the movable anchor wheel connects to a crankshaft, and the ram connects to the assembly. Then the crankshaft rotates the ram and the upper blade up and down.
Important tips for purchasing a sheet shearing machine
Shearing machines are one of the most importand and essential equipments in the manufacturing process. These machines cut, bend and roll metal sheets to their desired dimensions and shapes. As you know, paying attention to the smallest details leads to big improvements and changes for a manufacturing company. That is why it is very important to be careful in choosing the most appropriate shearing machine. In this essay, we have gathered useful information about shearing machines. We have also discussed the tips that buyers should consider before buying a cutting machine.
How to make a right decision
Companies often face many challenges in choosing the best sheet metal SHEARING machine. Obviously, each machine has its pros and cons that buyers need to research in order to be able to make the best decision.
Which is better, mechanical or hydraulic shearing machine?When buying a shearing machine, many people think that hydraulic cutting machines are a better option, they think of these machines as press-breaking machines, while cutting is a completely different process, and mechanical machines can be preferred to hydraulic devices for the following of reasons.
- Speed: Mechanical shears operate faster in a complete cycle.
- Simplicity: Mechanical shear have a simpler mechanism for maintenance and repair.
- Noise: Mechanical machines are less noisy because hydraulic oils do not flow continuously like a hudraulic machine.
- Cost-effective: Mechanical machines do not use hydraulic oil, there is no hydraulic heat (does not require cooling system), these machines do not require any filters.
Some shears design factors to consider
- Rake angle:
- Blade gap adjustment:
The rake angle is the angle of the upper blade, which is considered relative to the lower blade. This angle allows very small parts of the piece to engage with the blade. Therefore, it significantly reduces the force required to cut long pieces. Some manufacturers use a mechanism that allows us to perform shearing operations at any desired angle, which maximizes the shearing capacity of the machine.
In each shearing operation, the more the distance between the upper and lower blades, the less force required to break the workpiece. If the distance between the blades is too much, holes may be emerged in the workpiece. If the distance between the blades is adjusted too close together, the force required to cut the material will exceed the cutting capacity of the machine. Different materials such as aluminum, steel and stainless steel have different failure forces, so the distance between the blades in the cutting of each of these materials is different and must be adjusted separately to provide the best cutting quality. Normally, all types of sheet shearing machines can adjust the distance between the blades. However, in some of them this operation is done manually and in some of them using a mechanism, the distance between the blades is measured, which is naturally much faster in the latter case. In general, depending on the type and thickness of the parts you intend to cut, you must determine whether the purchase of a machine equipped with a blade spacing mechanism is necessary or economical or not.
Dener Makina Company
Dener Company is one of the manufacturers of metal industry machines in Turkey. This company has proven its ability in manufacturing and equipping industrial machines such as shearing machines, laser cutting machines, bending presses, etc. for many years. The video below shows one of the company's guillotine sheet shearing machines.
