Institutions centering clamping

Institutions centering clamping

 Precision CNC machining parts  When the work piece is processed by the central element of surface (axis, the center plane, etc.) for the base process in order to enable the base to reduce the positioning error of coincidence to be used centering clamping body.   

  Centering centering clamping body and clamping the two functions such as horizontal self-centering three-jaw lathe chuck is a classic example of the most commonly used.   

 Centering centering clamping the role of institutions according to their principle, there are two types, one is relying on the transmission mechanism so that mobile speed centering clamping device in order to achieve centering clamping, such as spiral leveraged institutions such as wedge; the other is the use of thin-walled elastic element force even after the elastic deformation (contraction or expansion), to achieve centering clamping, such as a spring clip drum, diaphragm chuck, bellows units, such as liquid plastic.

   1. Centering clamping body spiral   

   Precision CNC machining parts Rotary screw thread at both ends to the contrary, the same pitch. When it spins, the two V-shaped gag against the constant movement in order to achieve the centering of the work piece clamping or release. V-shaped work pieces of different shapes can shut up the replacement.

     Centering clamping bodies such features are: simple structure the work trip and general good but the centering accuracy is not high mainly suitable for rough or semi-finished tour of the needs of large and less demanding precision centering occasions.   

 2. Leveraged institutions centering clamping 

  Three-jaw self-centering leveraged trading cards, sleeve for axial movement the circle are three fabric hook lever will rotate around the axis, the three struck the slider along the radial movement of the cards in order to promote its claws the work piece centering and clamping or release.  

    Precision CNC machining parts  This centering clamping rigid body, and move fast, by force multiplier, and the work trip is also characterized by relatively large, but its relatively low precision centering. Generally about 0.1mm it is mainly used for rough work. Since the body can not self-locking lever, so that organizations rely on self-locking air pressure or other agencies. 

   3. Centering clamping wedge bodies  

   Wedge mobile folder automatically centering body claw when the work piece surface within the hole and left the position in the fixture after the six-cylinder through the rod so that the left claw clip due to the role of ontology on the slope while the left claw folder to the opened outside the bulge will be centering the workpiece clamping the other hand claw shifted to right folder in the role of spring circle card folder under claw to release the work piece.    

 Centering clamping bodies such compact structure usually ranging from precision centering 0.02mm~ 0.07mm compared with the hole for the workpiece surface for positioning the base of the semi-finishing processes.

  

Holding manipulator and synthesizing

Holding manipulator and synthesizing

Precision metalparts Holding manipulator and synthesizing the robot research and development condition in recent years, a economic scheme is concluded on the basis of the analysis of mechanical configuration, transform system, drive device and control system and guided by the idea of the characteristic and complex of mechanical configuration, electronic, software and hardware. In this article, the mechanical configuration combines the character of direction coordinate which can improve the stability and operation flexibility of the system. The main function of the transmission mechanism is to transmit power to implement department and complete the necessary movement. In this transmission structure, the screw transmission mechanism transmits the rotary motion into linear motion. Worm gear can give vary transmission ratio. Both of the transmission mechanisms have a characteristic of compact structure. The design of drive system often is limited by the environment condition and the factor of cost and technical lever. The step motor can receive digital signal directly and has the ability to response outer environment immediately and has no accumulation error, Precisionmetal parts which often is used in driving system. In this driving system, open-loop control system is composed of stepping motor, which can satisfy the demand not only for control precision but also for the target of economic and practicality. On this basis, the analysis of stepping motor in power calculating and style selecting is also given. The analysis of kinematics and dynamics for object holding manipulator is given in completing the design of mechanical structure and drive system.

 Current industrial approaches Precision metal parts to robot arm control treat each joint of the robot arm as a simple joint servomechanism. The servomechanism approach models the varying dynamics of a manipulator inadequately because it neglects the motion and configuration of the whole arm mechanism. These changes in the parameters of the controlled system sometimes are significant enough to render conventional feedback control strategies ineffective. The result is reduced servo response speed and damping, limiting the precision and speed of the end-effecter and making it appropriate only for limited-precision tasks. Manipulators controlled in this manner move at slow speeds with unnecessary vibrations. Any significant performance gain in this and other areas of robot arm control require the consideration of more efficient dynamic models, sophisticated control approaches, and the use of dedicated computer architectures and parallel processing techniques.

  

Quenching&annealing and Tempering’s different

Quenching&annealing and Tempering’s different

When the term “annealing” is applied to ferrous alloys without qualification, full annealing is applied. Precision metal parts This is achieved by heating above the alloy’s transformation temperature, then applying a cooling cycle which provides maximum softness. This cycle may vary widely, depending on composition and characteristics of the specific alloy.

   Quenching is a rapid cooling of a steel or alloy from the austenitizing temperature by immersing the workpiece in a liquid or gaseous medium. Quenching medium commonly used include water, 5% brine, 5% caustic in an aqueous solution, oil, polymer solutions, or gas (usually air or nitrogen).

  Selection of a quenching medium depends largely on the hardenability of material and the mass of the material being treating (principally section thickness).

  Precision metal parts The cooling capabilities of the above-listed quenching media vary greatly. In selecting a quenching medium, it is best to avoid a solution that has more cooling power than is needed to achieve the results, thus minimizing the possibility of cracking and warp of the parts being treated. Modifications of the term quenching include direct quenching, fog quenching, hot quenching, interrupted quenching, selective quenching, spray quenching, and time quenching.

  Tempering. Precision metal parts In heat treating of ferrous alloys, tempering consists of reheating the austenitized and quench-hardened steel or iron to some preselected temperature that is below the lower transformation temperature (generally below 1300 ℃ or 705 ℃). Tempering offers a means of obtaining various combinations of mechanical properties. Tempering temperatures used for hardened steels are often no higher than 300 ℃(150 ℃). The term “tempering” should not be confused with either process annealing or stress relieving. Even though time and temperature cycles for the three processes may be the same, the conditions of the materials being processed and the objectives may be different.

 

http://en.renohopmt.com/

Classification of Heat Treating Processes

Classification of Heat Treating Processes

 Precision CNC machining parts In some instances，heat treatment procedures are clear-cut in terms of technique and application．whereas in other instances，descriptions or simple explanations are insufficient because the same technique frequently may be used to obtain different objectives．For example, stress relieving and tempering are often accomplished with the same equipment and by use of identical time and temperature cycles．The objectives，however，are different for the two processes．

 The following descriptions of the principal heat treating processes are generally arranged according to their interrelationships．

 Normalizing consists of heating a ferrous alloy to a suitable temperature (usually 50°F to 100°F or 28℃ to 56℃) above its specific upper transformation temperature．This is followed by cooling in still air to at least some temperature well below its transformation temperature range．For low-carbon steels, the resulting structure and properties are the same as those achieved by full annealing；for most ferrous alloys, normalizing and annealing are not synonymous.

 Precision CNC machining parts  Normalizing usually is used as a conditioning treatment, notably for refining the grains of steels that have been subjected to high temperatures for forging or other hot working operations. The normalizing process usually is succeeded by another heat treating operation such as austenitizing for hardening, annealing, or tempering.

  Precision CNC machining parts Annealing is a generic term denoting a heat treatment that consists of heating to and holding at a suitable temperature followed by cooling at a suitable rate. It is used primarily to soften metallic materials, but also to simultaneously produce desired changes in other properties or in microstructure. The purpose of such changes may be, but is not confined to, improvement of machinability, facilitation of cold work (known as in-process annealing), improvement of mechanical or electrical properties, or to increase dimensional stability. When applied solely to relive stresses, it commonly is called stress-relief annealing, synonymous with stress relieving.

    

Heat treatment of metal

Heat treatment of metal 

  Precision CNC machining parts The generally accepted definition for heat treating metals and metal alloys is “heating and cooling a solid metal or alloy in a way so as to obtain specific conditions or properties.” Heating for the sole purpose of hot working (as in forging operations) is excluded from this definition．Likewise，the types of heat treatment that are sometimes used for products such as glass or plastics are also excluded from coverage by this definition．

 Transformation Curves 

 Precision CNC machining parts The basis for heat treatment is the time-temperature-transformation curves or TTT curves where，in a single diagram all the three parameters are plotted．Because of the shape of the curves，they are also sometimes called C-curves or S-curves．

 To plot TTT curves，the particular steel is held at a given temperature and the structure is examined at predetermined intervals to record the amount of transformation taken place．It is known that the eutectoid steel (T80) under equilibrium conditions contains，all austenite above 723℃，whereas below，it is the pearlite．To form pearlite，the carbon atoms should diffuse to form cementite．The diffusion being a rate process，would require sufficient time for complete transformation of austenite to pearlite．From different samples，it is possible to note the amount of the transformation taking place at any temperature．These points are then plotted on a graph with time and temperature as the axes．Through these points，transformation curves can be plotted as shown in Fig.1 for eutectoid steel． Precision CNC machining parts The curve at extreme left represents the time required for the transformation of austenite to pearlite to start at any given temperature．Similarly，the curve at extreme right represents the time required for completing the transformation．Between the two curves are the points representing partial transformation. The horizontal lines Ms and Mf represent the start and finish of martensitic transformation.

  

Drilling and Milling Machines

Drilling and Milling Machines 

      Precision CNC machining parts Upright drilling machines or drill presses are available in a variety of sizes and types, and are equipped with a sufficient range of apindle speeds and automatic feeds to fit the neds of most industries. Speed ranges on a typical machine are from 76 to 2025 rpm., with drill feed from 0.002 to 0.020 in.per revolution of the spindle.   

  Radial drilling machines are used to drill workpieces that are too large or cumbersome to conveniently move. The spindle with the speed and feed changing mechanism is mounted on the radial arm; by combining the movement of the radial arm around column and the movement of the spindle assembly along the arm, it is possible to align the spindle and the drill to any position within reach of the machine. For work that is too large to conveniently support on the base, the spindle assembly can be swung out over the floor and the workpiece set on the beside the machine.    

 Plain radial drilling machines provide only for vertical movement of the spindle; universal machines allow the spindle to swivel about an axis normal to the radial arm and the radial arm to rotate about a horizontal axis, thus permitting drilling at any angle. 

 A multispindle drilling machine has one or more heads that drive the spindles through universal joints and telescoping splined shafts. All spindles are usually driven by the same motor and fed simultaneously to drill the desired number of holes. In most machines each spindle is held in an adjustable plate so that it can be moved relative to the others. The area covered by adjacent spindles overlap so that the machine can be set to drill holes at any location within its range. 

   Precision CNC machining parts The milling operation involves metal removal with a rotating cutter. It includes removal of metal from the surface of a workspiece, enlarging holes, and form cutting, such as threads and gear teeth. 

Within an knee and column type of milling machine the column is the main supporting member for the other components, and includes the base containing the drive motor, the spindle, and the cutters. The cutter is mounted on an arbor held in the spindle, and supported on its outer extremity by a bearing in the overarm. The knee is held on the column in dovetail slots, the saddle is fastened to the knee in dovetail slots, and the table is attached to the saddle. Thus, the build-up the knee and column machine provides three motions relative to the cutter. A four motion may be provided by swiveling the table around a vertical axis provided on the saddle. 

 Precision CNC machining partsFixed-bed milling machines are designed to provide more rigidity than the knee and column type. The table is mounted directly on the machine base, which provides the rigidity necessary for absorbing heavy cutting load, and allows only longitudinal motion to the table. Vertical motion is obtained by moving the entire cutting head.   

  Tracer milling is characterized by coordinated or synchronized movements of either the paths of the cutter and tracing elements, or the paths of the workpiece and model. In a typical tracer mill the tracing finger follow the shape of the master pattern, and the cutter heads duplicate the tracer motion.

Operational safety and environmental protection

Operational safety and environmental protection

 Precision wire cutting Along with advance in technology and human culture development, the people are more and more high to the working condition improvement and the environmental protection request. The electric spark forming processing as a result of its own characteristic, can have the driving fluid splash, the smog, the noise, the electromagnetic radiation, the noxious gas inevitably in the processing process and so on the safety factor and the pollution, is noticeable to the operator personal safety and the environment harm. Therefore, for the guarantee electrical finishing industry sustainable development, must act according to “the green manufacture principle”, the realization resources most effective use and the reject threshold produces with the emissions. Should take following measure specifically:

①         Precision wire cutting Seal engine bed work area. This is advantageous to the improvement driving fluid, the smog, the electromagnetic radiation and so on to the human body, the engine bed, the working conditions pollution, is advantageous in the operating process prevented receives an electric shock the danger as well as to the noxious gas centralized processing emissions;

 ②Precision wire cutting Vicarious technical utilization. For example, the environmental pollution which creates for the reduced use driving fluid, may in the guarantee processing efficiency, the processing precision, the processing cost as well as under the processing process stable premise, selects the pollution small driving fluid as far as possible, simultaneously should study, the development vigorously does not use the driving fluid the formed processing technology;

  ③ Reject post-processing. The waste liquid, the waste gas produces which after the processing in must pass through processing to be able to discharge. Needs to point out specially, has pollutant reasonable processing to the processing process, not only is advantageous to the enhancement work security, the reduction environmental pollution, but also is advantageous in improves operator's working conditions, causes when the operator work the mood is happy, this regarding enhances the electrical finishing industry the social image and the market competitive power also is extremely beneficial.