1. General rules of tool path:
Rough cutting: Under the maximum load of the machine tool, in most cases, the largest possible cutter, the largest possible feed amount, and the fastest possible feed should be selected. In the case of the same knife, the feed is inversely proportional to the amount of feed. Under normal circumstances, the load of the machine tool is not a problem. The principle of tool selection is mainly based on whether the two-dimensional angle and three-dimensional arc of the product are too small. After selecting the tool, determine the length of the tool. The principle is that the length of the tool is greater than the processing depth. For large workpieces, it is necessary to consider whether the chuck interferes.
picture
Light knife: The purpose of light knife is to meet the processing requirements of the surface finish of the workpiece and reserve an appropriate margin. In the same way, the light knife chooses the largest possible knife and feeds as fast as possible, because the fine knife takes a long time, use the most suitable knife and feed. Under the same feed, the larger the lateral feed, the faster the feed. The feed amount of the curved surface is related to the smoothness after processing. Use the largest knife, the fastest speed, and the appropriate feed.
2. Clamping method:
1. All clamps are horizontally long and vertically short.
2. Vise clamping: The clamping height should not be lower than 10 mm, and the clamping height and processing height must be specified when processing the workpiece. The processing height should be about 5mm higher than the plane of the vise, the purpose is to ensure firmness without hurting the vise. This kind of clamping is a general clamping, and the clamping height is also related to the size of the workpiece. The larger the workpiece, the corresponding increase in the clamping height.
3. Clamping of the splint: the splint is coded on the workbench with a sizer, and the workpiece is locked on the splint with screws. This kind of clamping is suitable for workpieces with insufficient clamping height and large processing force. Generally, the effect is better for medium and large workpieces. .
4. Clamping with code iron: When the workpiece is large and the clamping height is not enough, and it is not allowed to lock the thread at the bottom, use code iron for clamping. This kind of clamping requires secondary clamping, first code the four corners, process the other parts, then code the four sides, and process the four corners. When clamping for the second time, do not let the workpiece loosen, first code and then loosen. It is also possible to code both sides first and process the other two sides.
5. The clamping of the tool: the diameter is above 10mm, and the clamping length is not less than 30mm; the diameter is below 10mm, and the clamping length is not less than 20mm. The clamping of the tool should be firm, strictly prevent the tool from colliding and directly inserting into the workpiece.
3. Classification of knives and their scope of application:
1. According to the material:
White steel knife: easy to wear, used for roughing copper and small steel materials.
Tungsten steel knife: used for clearing corners (especially steel) and light knife.
Alloy Knife: Similar to Tungsten Steel Knife.
Purple knife; used for high-speed cutting, not easy to wear.
2. According to the cutter head:
Flat bottom knife: used for flat and straight sides, clearing the plane angle.
Ball knife: used for light and light knives on various curved surfaces.
Ox nose knife (with one side, two sides and five sides): used for roughing steel materials (R0.8, R0.3, R0.5, R0.4).
Coarse leather knife: used for roughing, pay attention to the method of leaving the margin (0.3).
3. According to the tool holder:
Straight knife: Straight knife is suitable for various occasions.
Inclined knife: but not suitable for straight surfaces and surfaces with a slope smaller than the slope of the rod.
4. According to the blade:
Two blades, three blades, four blades, the more blades, the better the effect, but the more work, the speed and feed should be adjusted accordingly, and the more blades, the longer the life.
5. The difference between the ball knife and the flying knife light knife:
Ball knife: When the concave ruler is smaller than the ball ruler, and the plane ruler is smaller than the ball R, the light will not reach (the bottom corner cannot be cleared).
Flying knife: The advantage is that it can clear the bottom corner. Comparison of the same parameters: V=R*ω The rotation speed is much faster (flying knife), the light is bright when it is powerful, and the flying knife is mostly used for contours, and sometimes the flying knife does not need the middle light. The disadvantage is that the size of the concave surface and the plane ruler are less than the diameter of the flying knife.
Four, processing copper
1. Under what circumstances do copper males (electrodes) need to be made:
If the knife does not go down at all, it will be a Tonggong. In a Tonggong, there are still some that can’t go down. The shape is protruding and needs to be divided again.
The knife can go down, but the knife that is easy to break also needs to be a copper male, which depends on the actual situation.
Products requiring fire patterns need to be made of copper.
If the copper male cannot be made, the bone position is too thin and too high, the male is easy to be damaged and deformed, and the deformation and sparking deformation during processing require inserts at this time.
The east and west surfaces processed by Tonggong (especially the curved surface will be very smooth and uniform) can overcome many problems in precision gongs and many problems in drawing.
When precise shape or large margin is required, thick copper male must be made.
2. Tonggong's approach:
Select the surface to be made of copper, complete the surface to be supplemented, or extend the surface to be extended, to ensure that all edges of the copper are larger than the edge to be punched without damaging the surface of other products, and remove unnecessary cleaning. The plane angle (the intersection with the plane angle is a deeper glue position), make up a regular shape; find the maximum shape of the copper male, use a boundary and then project it to the supporting surface; determine the size of the reference frame, cut off the supporting surface, and This copper map is basically completed; material preparation: length * width * height, length and width ≥ Ymax and Xmax as the reference frame The length and width of the actual copper material must be greater than the reference frame on the drawing. Height ≥ theoretical size of copper male + reference frame height + clamping height.
5. Problems with fixed number of drawings
1. In the absence of a ready-made processing surface, the four sides of the plane are divided into centers, the center is aligned with the origin, and the top is facing zero. If the top surface is uneven (for copper males), a margin of 0.1 is left, that is, when the number is touched, the actual alignment is 0 (z ), which is lower than 0.1 in the figure.
2. When there is a ready-made processing surface, make the ready-made face on the diagram 0(z), and divide the plane if it can be divided into centers. Otherwise, the actual height and width of the processed surface should be checked if the ready-made side touches the number (single side). , The length is different from the drawing, and it is programmed according to the actual material. In general, first process to the size on the drawing and then process the shape on the drawing.
3. When multiple positions are to be processed, for the first position (standard position), the benchmarks of the other positions must be fixed, the length, width and height must be fixed, and all the benchmarks for the next processing must be processed last time. face shall prevail.
4. Positioning of the insert: place it inside the whole, pad the bottom to a certain height and then raise the drawing to this height. Centering; a rough point can be centered with the largest shape; cut a fixture, divide according to the fixture, determine the relative position of the insert drawing and the fixture, and then place the origin of the drawing on the center point of the fixture.
Sixth, rough cutting tool path selection:
1. Surface digging
The key is the selection of the range and the selection of the surface.
The area of tool path processing is: the selected surface in the selected range is used as the termination surface, and all places where the tool can go down from the highest point to the lowest point are the principle. The selected surface is preferably the whole surface, and the boundary can only be the area to be processed. The distance without surface is less than half the tool radius, because there is enough margin for other surfaces so it is automatically protected; it is best to extend the lowest line, because There is a R gong at the lowest point.
Knife selection: If the tool cannot feed in a spiral or oblique line, or the area that cannot be processed, the area that cannot be entered by the knife is sealed, and it is left for the second roughing.
Before smoothing the knife, you must roughen all the unroughed areas, especially small corners, including two-dimensional corners, three-dimensional corners and sealed areas, otherwise the knife will break. Secondary roughing: Generally, three-dimensional grooving is used to select the range, and flat-bottomed knives can be used for plane grooving and shape tool paths. To reach the selected boundary from the center of the tool without damaging other surfaces, generally do not refine the boundary, use fast two-way angle depending on the situation, spiral feed, angle 1.5 degrees, height 1, when the shape of the groove is strip, it cannot The spiral lower knife uses a slanted line to feed the knife. Generally, the filter is opened, especially when the curved surface is rough. The plane of the knife should not be low to avoid collision with the knife.
Retraction: Generally, relative retraction is not needed, but absolute retraction is used, and relative retraction is used when there is no island.
2. Plane grooving: milling various planes, concave and flat grooves. When milling some open planes, it is necessary to define the boundary. In principle, the tool can enter (greater than one tool radius), and the open part is more than half of the tool radius, closed peripheral.
3. Shape: When the selected plane is suitable for shape layering, use the layered shape to lift the knife (plane shape). When the point of lifting the knife and the point of lowering the knife are at one point, there is no need to lift the knife. Z plane generally lifts the knife, and the relative height should not be used as much as possible. ;Correction direction is generally right correction (towards the knife).
4. Tool path setting of mechanical correction: the correction number is 21, change the computer correction to mechanical correction, the feed is vertical feed, and the place where the knife cannot pass is changed to a large R without leaving a margin.
5. Contour shape: it is suitable for closed surfaces. If it is an open surface, if there are four circles, the top surface should be sealed. If it is within four circles or not, the range and height should be selected (certainly arc-shaped knife opening rough ), used for roughing: the machining distance in any plane is less than one tool radius, if it is larger than one tool radius, a larger tool or two equal-height shapes should be used.
6. Curved surface streamline: with the best uniformity and crispness, it is suitable for light knife and can replace the contour shape in many cases.
7. Radial tool path: suitable for situations with large holes in the middle (rarely used). Note: When the knife is played, the knife is not sharp, the knife is too long, and when the workpiece is too deep, it should be circled and cannot go up and down; the sharp corners of the workpiece should be divided into two cutting paths, and the edge should not be crossed. The edge of the light knife is the best Extend (use arc to advance and retreat the knife).
