Grinding machine

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Rotating abrasive wheel on a bench grinder. Rotating grinder.gif
Rotating abrasive wheel on a bench grinder.
Pedal-powered grinding machine, Russia, 1902. 1902 - Grinding machine.jpg
Pedal-powered grinding machine, Russia, 1902.

A grinding machine, often shortened to grinder, is any of various power tools or machine tools used for grinding. It is a type of material removal using an abrasive wheel as the cutting tool. [1] Each grain of abrasive on the wheel's surface cuts a small chip from the workpiece via shear deformation.

Contents

Grinding as a type of machining is used to finish workpieces that must show high surface quality (e.g., low surface roughness) and high accuracy of shape and dimension. As the accuracy in dimensions in grinding is of the order of 0.000025  mm, in most applications, it tends to be a finishing operation and removes comparatively little metal, about 0.25 to 0.50  mm depth. However, there are some roughing applications in which grinding removes high volumes of metal quite rapidly. Thus, grinding is a diverse field.

Overview

The grinding machine consists of a bed with a fixture to guide and hold the workpiece and a power-driven grinding wheel spinning at the required speed. The wheel’s diameter and the manufacturer’s rating determine the speed. The grinding head can travel across a fixed workpiece, or the workpiece can be moved while the grinding head stays in a fixed position.

Fine control of the grinding head or table position is possible using a vernier calibrated hand wheel or using the features of numerical controls.

Grinding machines remove material from the workpiece by abrasion, which can generate substantial amounts of heat. To cool the workpiece so that it does not overheat and go outside its tolerance, grinding machines incorporate a coolant. The coolant also benefits the machinist as the heat generated may cause burns. In high-precision grinding machines (most cylindrical and surface grinders), the final grinding stages are usually set up so that they remove about 200  nm (less than 1/10000  in) per pass - this generates so little heat that even with no coolant, the temperature rise is negligible.

Types

A surface grinder. SurfaceGrinder-Proth-insetMagChuck.jpg
A surface grinder.
A cylindrical grinder. Cylindrical grinder, Landis, photo 291.png
A cylindrical grinder.

These machines include the:

Centre Grinding Machine Henninger Zentrumschleifmaschine ZS102.jpg
Centre Grinding Machine

See also

Related Research Articles

<span class="mw-page-title-main">Metalworking</span> Process of making items from metal

Metalworking is the process of shaping and reshaping metals in order to create useful objects, parts, assemblies, and large scale structures. As a term, it covers a wide and diverse range of processes, skills, and tools for producing objects on every scale: from huge ships, buildings, and bridges, down to precise engine parts and delicate jewelry.

An abrasive is a material, often a mineral, that is used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away by friction. While finishing a material often means polishing it to gain a smooth, reflective surface, the process can also involve roughening as in satin, matte or beaded finishes. In short, the ceramics which are used to cut, grind and polish other softer materials are known as abrasives.

<span class="mw-page-title-main">Machining</span> Material-removal process; manufacturing process

Machining is a manufacturing process where a desired shape or part is created using the controlled removal of material, most often metal, from a larger piece of raw material by cutting. Machining is a form of subtractive manufacturing, which utilizes machine tools, in contrast to additive manufacturing, which uses controlled addition of material.

<span class="mw-page-title-main">Bench grinder</span> Grinding machine

A bench grinder is a benchtop type of grinding machine used to drive abrasive wheels. A pedestal grinder is a similar or larger version of grinder that is mounted on a pedestal, which may be bolted to the floor or may sit on rubber feet. These types of grinders are commonly used to hand grind various cutting tools and perform other rough grinding.

<span class="mw-page-title-main">Grinding wheel</span> Abrasive cutting tool for grinders

Grinding wheels are wheels that contain abrasive compounds for grinding and abrasive machining operations. Such wheels are also used in grinding machines.

A grinding dresser or wheel dresser is a tool to dress the surface of a grinding wheel. Grinding dressers are used to return a wheel to its original round shape, to expose fresh grains for renewed cutting action, or to make a different profile on the wheel's edge. Utilizing predetermined dressing parameters will allow the wheel to be conditioned for optimum grinding performance while truing and restoring the form simultaneously.

<span class="mw-page-title-main">Tool and cutter grinder</span>

A Tool and Cutter Grinder is used to sharpen milling cutters and tool bits along with a host of other cutting tools.

<span class="mw-page-title-main">Turning</span> Machining process

Turning is a machining process in which a cutting tool, typically a non-rotary tool bit, describes a helix toolpath by moving more or less linearly while the workpiece rotates.

Superfinishing, also known as microfinishing and short-stroke honing, is a metalworking process that improves surface finish and workpiece geometry. This is achieved by removing just the thin amorphous surface layer of fragmented or smeared metal left by the last process with an abrasive stone or tape; this layer is usually about 1 μm in magnitude.

<span class="mw-page-title-main">Polishing (metalworking)</span> Abrasive process for creating smooth finished surfaces

Buffing are finishing processes for smoothing a workpiece's surface using an abrasive and a work wheel or a leather strop. Technically, polishing refers to processes that uses an abrasive that is glued to the work wheel, while buffing uses a loose abrasive applied to the work wheel. Polishing is a more aggressive process, while buffing is less harsh, which leads to a smoother, brighter finish. A common misconception is that a polished surface has a mirror-bright finish, however, most mirror-bright finishes are actually buffed.

<span class="mw-page-title-main">Diamond tool</span> Cutting tool with diamond grains

A diamond tool is a cutting tool with diamond grains fixed on the functional parts of the tool via a bonding material or another method. As diamond is a superhard material, diamond tools have many advantages as compared with tools made with common abrasives such as corundum and silicon carbide.

<span class="mw-page-title-main">Rotary tool</span> Handheld power tool used for grinding, drilling, machining, etc.

A die grinder or rotary tool is a handheld power tool and multitool used for grinding, sanding, honing, polishing, or machining material. All such tools are conceptually similar, with no bright dividing line between die grinders and rotary tools, although the die grinder name tends to be used for pneumatically driven heavy-duty versions whereas the rotary tool name tends to be used for electric lighter-duty versions. Flexible shaft drive versions also exist.

<span class="mw-page-title-main">Cylindrical grinder</span> Grinding machine

The cylindrical grinder is a type of grinding machine used to shape the outside of an object. The cylindrical grinder can work on a variety of shapes, however the object must have a central axis of rotation. This includes but is not limited to such shapes as a cylinder, an ellipse, a cam, or a crankshaft.

<span class="mw-page-title-main">Centerless grinding</span> Machining process

Centerless grinding is a machining process that uses abrasive cutting to remove material from a workpiece. Centerless grinding differs from centered grinding operations in that no spindle or fixture is used to locate and secure the workpiece; the workpiece is secured between two rotary grinding wheels, and the speed of their rotation relative to each other determines the rate at which material is removed from the workpiece.

<span class="mw-page-title-main">Grinding (abrasive cutting)</span> Machining process using a grinding wheel

Grinding is a type of abrasive machining process which uses a grinding wheel as cutting tool.

<span class="mw-page-title-main">Honing (metalworking)</span> Production of a precise surface on a metal workpiece

Honing is an abrasive machining process that produces a precision surface on a metal workpiece by scrubbing an abrasive grinding stone or grinding wheel against it along a controlled path. Honing is primarily used to improve the geometric form of a surface, but can also improve the surface finish.

Electrochemical grinding is a process that removes electrically conductive material by grinding with a negatively charged abrasive grinding wheel, an electrolyte fluid, and a positively charged workpiece. Materials removed from the workpiece stay in the electrolyte fluid. Electrochemical grinding is similar to electrochemical machining but uses a wheel instead of a tool shaped like the contour of the workpiece.

Surface grinding is done on flat surfaces to produce a smooth finish.

<span class="mw-page-title-main">Flat honing</span> Metalworking grinding process

Flat honing is a metalworking grinding process used to provide high quality flat surfaces. It combines the speed of grinding or honing with the precision of lapping. It has also been known under the terms high speed lapping and high precision grinding.

Grinding wheel wear is an important measured factor of grinding in the manufacturing process of engineered parts and tools. Grinding involves the removal process of material and modifying the surface of a workpiece to some desired finish which might otherwise be unachievable through conventional machining processes. The grinding process itself has been compared to machining operations which employ multipoint cutting tools. The abrasive grains which make up the entire geometry of wheel act as independent small cutting tools. The quality, characteristics, and rate of grinding wheel wear can be affected by contributions of the characteristics of the material of the workpiece, the temperature increase of the workpiece, and the rate of wear of the grinding wheel itself. Moderate wear rate allows for more consistent material size. Maintaining stable grinding forces is preferred rather than high wheel wear rate which can decrease the effectiveness of material removal from the workpiece.

References

  1. "Grinding machine | Grinding Wheels, Abrasives, Precision | Britannica". www.britannica.com. Retrieved 2024-10-31.
  2. "Boron Carbide: Key Properties & Applications". Advanced Ceramic Materials. April 12, 2024. Retrieved October 1, 2024.
  3. CNpatent 103770027A