CNC engraving technology is the combination of traditional engraving technology and modern CNC technology.CNC engraving machine integrates computer aided design (CAD) technology, computer aided manufacturing (CAM) technology, numerical control (NC) technology and precision manufacturing technology, which is a new unique and advanced CNC machining machine tool.Compared with traditional CNC equipment, engraving machine has the advantages of high speed, high processing efficiency of soft materials, good surface quality and high cost performance.With the advent of CNC technology, cutting tools can be controlled by computer, so that wood products curve, carving, drilling, grooving and other complex processes to achieve mechanization and automation.

    1. Structure of CNC engraving machine

    CNC engraving machine is mainly composed of engraving machine tool, electric control cabinet, control computer, engraving control software and other basic parts, while engraving machine is composed of working table base, fixed working table, movable gantry frame and spindle.The spindle cutting knife moves in the direction of X and Z axis, and the gantry moves in the direction of Y axis, thus forming a three-coordinate three-axis linkage mechanism.

    CNC engraving system is mainly composed of two relatively independent parts from a functional point of view.

    (1) Engraving CAD/CAM software: it is used for engraving product graphic design, shape and calculation of engraving product processing path data, output NC code that can be identified, interpreted and finally completed by CNC engraving machine.

    (2) CNC engraving equipment: the engraving machine tool, which is the specific part of CNC engraving, can interpret the NC machining code output by the engraving CAD/CAM software, perform various complex machining actions described by the machining code, and complete the engraving production task.

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    2, engraving graphics finishing, path programming and processing methods

    The commonly used software for engraving graphic design is CAD graphics assistant design software. Common programming software for CNC engraving machine includes TPE3, Wentai, Cimatron, ARTCAM, etc. The machine tool control system is NCstudio engraving machine control system.

    (1) Analyze and sort out the design drawings to determine the processing technology

    First of all, we should carefully study THE CAD design drawings, according to the specific requirements of processing, analyze which parts of the parts to be processed should be engraved, belong to Yin carving or Yang carving, and on the basis of the original design drawings to delete or draw an accurate path.When sorting out CAD drawings, it is necessary to pay attention to the CAD graphics should not have redundant lines and points, if there should be deleted or re-edit, it is better to edit broken lines or scattered lines into a whole multi-segment line, the plane graphics plane domain to be processed into the overall graphics, in order to edit the tool path in The Ventai programming software.If there are redundant lines or points in the processed CAD graphics, it is easy to make mistakes when programming with The Ventai programming software, resulting in deviation or repetition of the path, resulting in processing errors.

    (2) Edit and carve processing tools, processing parameters and generated tool paths

    CNC engraving is accomplished by computer control of the execution parts of the machine tool and controlled by numerical machining instructions.That is, the operator USES V8 Ventai engraving design software to draw accurate engraving data graphics according to the requirements of engraving processing according to the formed process planning and design drawing.The engraving graphics are the basis of the operation command generation of the engraving machine, and the key to the smooth completion of the engraving graphics is to master the drawing and editing commands of the engraving software.

    Cutting tool path is in the process of the machine tool processing line cutting tool center orbit, and processing procedures and engraving machine carving work instruction, it is made of engraving software according to the operation personnel of process planning and designing the data graphic calculation with how to control CNC engraving machine in the machining process with a knife, determine the cutting depth and feed processing program.

    The generation of tool path is completed by the engraving software. The key is to make the correct process planning according to the processing figure, the processing material and the processing tool. The engraving software calculates the tool path according to the planned process and engraving design figure.

    Generating tool path can be divided into the following six steps:

    1*Choose to carve processing graphics

    2*choose the engraving processing method, and determine the engraving scope
    3*Select the engraving tool and modify the calculation Settings

    4*choose the engraving material, and set the cutting parameters

    5*Generate engraving processing parameters

    6*Generate tool paths.

    Before the CNC engraving machine starts automatic processing, the operator will load the processing program, select the tool for loading and unloading, clamp the material and set the cutting parameters. In other work, the engraving machine will carry out cutting processing with the tool according to the tool path calculated by the engraving software. The machining process will be carried out automatically without intervention during normal processing.

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    3. The application of CNC engraving machine in the processing of solid wood composite door

    (1) Processing wood door pressure line

    As a result of the pressing line of a lot of solid wood compound door is circular arc shape or unusual shape, have certain difficulty when processing, and waste material.If the engraving machine processing can use the method of overcutting and marking, according to the size of the CAD drawing after programming import, and then processing, both save material and convenient and feasible.Because the workpiece clamping is generally in the edge position, it is necessary to measure and calculate whether the fixture installation position is in the path of tool operation.If the tool running path is likely to occur in the tool and fixture collision, resulting in the pre-set workpiece origin deviation, resulting in path deviation, processing waste;The collision between tool and fixture will not only make the machining error, but also may damage the tool and the machine tool, affecting the machining accuracy of the machine tool;In addition, the fixture is difficult to fix each processing part in the center of the plate parts. When the processing is about to be completed, the workpiece will collapse due to the few connections between the parts and the plate parts, not effectively clamped and the high tool speed, which is relatively dangerous and prone to stubble breakage.So before the processing should pay attention to the thickness of the direction of a certain allowance for processing, to ensure that the processing parts and plate more connected, to prevent the occurrence of the above situation.

    (2) Decorative patterns on the surface of processed wooden doors

    Check the machine tool and clear the working table, install the wooden door, install the tool and set the origin of the workpiece to be processed.According to the pre-designed and edited processing program for automatic processing, processing should pay attention to the engraving size and design size is correct, because the workpiece origin is set visually, the processed product and design size will have a certain error.Should pay attention to according to the wooden door material set processing machine spindle speed and feed speed, so as not to process the product can not guarantee the accuracy and surface roughness.The linear decorative pattern on the surface of this wood door generally USES a cutter for the round bottom of 6mm, carving depth to 3mm for the appropriate parameters of the machine tool set as: spindle speed 20000r/min, feed speed of the machine tool set value of 20% ~ 30% for the appropriate.

    (3) Processing solid wood composite door frame

    The structure of the solid wood composite door determines that the panels and glass frame should be carved on the door, and then the panels and glass should be nailed on the line.Paneled doors and glass doors need high machining precision, and the engraving machine can ensure the machining precision.Using a knife when processing the diameter of 12 mm, tall, in 40 mm straight knife blade processing, step by step feed, the feed is not more than 10 mm. When processing the spindle speed of 20000 r/min commonly, general according to the hardness of lumber and tool feed rate the sharp degree of about 20% of the value choice, feed speed too slow will cause the workpiece burnt, too fast will appear ripple affect surface roughness, generally in the solid wood floor processing feed speed slightly faster, easier because real wood floor processing.

    (4) Processing keyhole

    Check the machine tool and clear the working table, install the wooden door, install the tool and set the origin of the workpiece.Debug the machine according to the keyhole machining program designed and edited in advance.When the tool runs to the given position, keep the X and Y axes motionless, manually control the machine to move along the axis direction, and process the keyhole on the surface of the wooden door.

    (5) processing on the door or mother door tongue-and-groove

    Debug the machine according to the pre-designed and edited processing program.Check the machine tool and clear the working table, install the wooden door, install the tool and set the origin of the workpiece to be processed.When the tool is running to the given position, keep the X and Z axes unchanged to make the machine move along the Y axis, and process the tongue-and-groove at the edge of the wooden door.With engraving machine processing wooden door tongue-and groove can be accurate to 0.01mm, the shape of the tongue-and groove has high precision, smooth processing surface and other advantages in the processing because some wooden doors have a slight bending, so should pay attention to when clamping fixture firm clamping.

    (6) Machining arc or shaped pieces of the template

    In the wood door processing there are a lot of panels are circular arc or shaped, in the end milling machine processing is very difficult and more dangerous, need to make a template, clamping after by die milling.The precision requirements of arc parts and special-shaped parts template are very high and difficult to be machined. It will be very simple to be machined by engraving machine. As long as accurate drawings are designed in AD and programmed into AD, automatic machining can be carried out.

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    CNC engraving machine is a CNC carving and milling machine with the function of computer numerical control. The tools installed are shank milling cutter like the carving and milling machine. Most of the processing procedures can be completed by carving machine.