• Types of machining according to their industrial process.

• Main types of grinding machines according to the desired result.

• Advantages of CNC grinding machines.

 

The first thing we must be clear about when selecting a machine is the machine for the tool making machine is the type of machining we need to perform, as there are different types.

The machining is the set of industrial processes carried out on a piece of raw material raw material or semi-finished products, which although generally made of metal, are metal. It can also be used for machining plastic parts, wood or other rigid materials. During the process the excess material is removed to acquire the final shape and size required for the manufacturing of the manufacture.

The types of are divided into three main types groups depending on the type of operation performed on the raw material. They are generally combined with each other to achieve the desired optimum result in the manufactured parts.

 

1. Machining without chip removal:

These are the processes of forming to which metal parts (with the exception of castings) are subjected at least once during their manufacture, although they may also have been subjected to several times. This type of machining by no chip removal provides significant savings savings of raw material. Examples of machining of workpieces without chip removal are the molding and forging. In the case of pressing, the threaded or drawing by transforming the shape and size of the part without technically removing material, some experts do not include them in this classification.

 

2. Abrasive machining:

It is the process of removal of excess material excess material on a part by abrading it in small quantities, causing particles of material to be released, sometimes incandescent. The machine tool used for this type of machining is the grinding wheel grinding wheel. This type of machining is carried out with a machine equipped with a disc whose surface is made of the following materials abrasives made of quartz grains, silicon carbide, carborundum or corundum and a binder, which remove very small amounts of material. scratching its surface and thus be able to achieve tolerance limits and finishes characteristic surface characteristics, which other machining processes cannot achieve, but within a range of longer time.

 The main protagonist of this article of our blog: grinding machine.

Most experts consider abrasive machining to be the most abrasive machining is more of a finishing process than a finishing finishing process.

 

3. Machining with chip removal:

These are the processes of machining by which the material is removed o cut with a machine tool generating a scrap or chip, using various cutting edges, or cutting edges o blades perfectly defined. There is a wide variety of machining with chip removal such as drilling, sawing (by sawing, laser…) or milling (sawing, laser…) or milling. Depending on the type of machining, the waste is greater or lesser, and therefore the need for machining processes is greater or lesser. 

 

 

 

How do grinding machines work?

 

The machines used in the grinding of machined parts machined parts are known as grinding machines.
Since there are many different types of grinding, the industry also has a corresponding number of versions of grinding machines. grinding machines appropriate to the result that needs to be obtained.

As its name suggests, a grinding grinding machine is a machine whose purpose is to grind the finish of a part of a part according to different requirements, either by very specific measures, or dimensional tolerances (angle or diameter), geometric (cylindricity or other shapes) or surface finish (roughness).

The grinding machines are used, for example, for the manufacture of bearings, guides, dies, plates, rings, molds, pins and profiles for tooling, precision rings or segments, etc. using abrasive machining. abrasive machining.

The machining of parts by abrasion abrasive machining as we already know, is one of the three processes that remove material remove material of a part in order to shape and model it according to its subsequent application. It differs from the other processes of machining because the disposal of excess material is relatively low material is relatively low, so it is more of a part finishing process and the tool used for this. The tool used for this process, as mentioned above, is a grinding wheel, which is used to remove the excess material. grinding wheel.

 

 

The 5 main types of grinding machines:

 

1. Flat or surface grinding machines:

 

These machines are the easiest to operate, as they consist only of a single longitudinal longitudinal slide which gives the translation movement to the workpiece and the grinding wheel, which gives the rotational movement rotation. Two subtypes are distinguished according to the position of the tooth:

a) Face grinding machines: the grinding wheel rotates on a vertical spindle, works flat against the workpiece and moves in a rectilinear motion. They are generally used for fast material removal, although some machines can achieve high precision.

b) Tangential grinding machines: the grinding wheel rotates on a horizontal spindle, works edgewise on the workpiece and moves in a circular and pendular motion. They are used for high-precision work on simple flat surfaces, flared or inclined surfaces, grooves, flat surfaces close to shoulders, recessed surfaces and profiles.

These surface or flat grinding machines are used for are used for flat workpiece usually machined on other machines in the shop, such as lathes or lathes, milling machines  and polishers machines. The workpieces are fixed to the bed by means of a magnetic clamping plate and can be moved manually or mechanically under the grinding wheel. The machine is equipped with an internal pump and a network of pipes for the automatic application and recirculation of a cooling liquid for the workpiece and the grinding wheel.

 

SG SERIE 5015AHR Flat Grinding Machine SG SERIES 5015AHR

 

 

2. Cylindrical grinding machines:

 

The cylindrical grinding machine can operate in a variety of ways, however, the part must have a central axis of rotation. This includes, but is not limited to, forms such as a cylindera conea ellipsea cam or a crankshaft. Several subtypes are also distinguished:

a) External cylindrical grinding machinesGrinding is performed on the external surface of a workpiece between centers, which allow the rotation of the workpiece. In turn, the grinding wheel also rotates in the same direction when it comes into contact with the workpiece.

b) Internal cylindrical grinding machines: grinding is performed on the inside of a workpiece. The grinding wheel is always smaller than the width of the workpiece. A metal ring holds the piece, giving it movement.

c) Centerless grinding machines: This type of machine grinds small cylindrical parts, such as bushings, pins or pins. The mechanism consists of two grinding wheels rotating in the same direction, between which the workpiece is placed, without clamping (this is why the mechanism is called “centerless”), which rotates in the opposite direction to that of the wheels, driven by the movement of the driving wheel, which is inclined at an angle of between 1 and 5 degrees, depending on the hardness of the material to be ground and the diameter of the workpiece.

 

 

3. Universal grinding machines:

 

These are the machines that offer greater working capacity since they machine bodies of revolution. With these machines of great robustness and size grinding of the outside and inside of camshafts, crankshafts, cylinder bores, cones, liners and many other parts is achieved.

The longitudinal carriage of the machine provides the translation movement to the rotating parts through its automatic advance and return provided by a hydraulic mechanism hydraulic mechanism while the grinding wheels receive the rotational movement, opposite to that of the workpiece. The hardness or characteristics of the parts define the shaft rotation speed by means of speed controllers.

 

 

4. Special grinding machines:

 

For the grinding of parts with a certain mechanical geometry or which contain holes and cannot rotate on themselves, special machines are used, which are generally of small dimensions and wingspan and are known as special grinding machines. They have a vertical spindle (sometimes called planetary spindle) whose grinding wheel, in addition to rotating, performs a circular translation. These machines are used, for example, to grind an infinite number of parts, such as, among others, gear teeth, profiles, gearwheels, threads, rolling cylinders, bed guides brake pads, splines, hobs, bearings, spokes, turbine blades, and aircraft landing gear.

With regard to the main tool of the grinding machines, the grinding wheel. There are a variety of grinding wheels of different shapes and grit sizes, all of which are standardized by international standards.

 

MT-210 x 750 slant bed CNC turning center

 

 

5. Grinding machines with CNC control system:

 

One of the most important technological advances that has been introduced into the grinding machine market is a CNC control  on these 5 main types of grinding machines, which provides a number of advantages over conventional advantages over conventional grinding machines among which we can highlight:

• The unification of movements for grinding (top, front and bottom) with a single machine.
• Full automation, with minimal operator intervention.
• Larger machine dimensions, making it possible to grind parts of larger sizes.
• Magnetic workpiece clamping systems for greater precision.
• The availability on the market of various forms of benches or work tables.
• Optimization of grinding times and precision.
• The incorporation of servomotors for each axis, which allows a more precise positioning of the part.
• Automatic control of the condition of the grinding wheels, for their replacement.
• Possibility to program Cartesian coordinates and set the exact grinding distance.
• Operation in a closed environment, thanks to its protective screens, with no external projection of chips, dust or debris.

 

Fanuc 0i-T CNC assembly