Method for processing traction machine frame based on numerical control milling machine

Abstract

The application discloses a method for processing a traction machine frame based on a numerical control milling machine, which comprises the following steps: a first process: a frame blank is clamped on a workbench of a numerical control planer milling machine in a posture with a back face downward, is corrected and positioned, and in a once clamped state, milling machining is sequentially completed on a bearing gland mounting surface of a front face of the frame, a clamping cylinder mounting surface and a tension shaft hole boss surface, and drilling machining is completed on the front face tension shaft hole and the clamping cylinder bolt hole; all the front face and bottom face elements are processed in the first process, the strict parallelism and coaxiality requirements between the front face and the back face are effectively ensured, the machining precision is improved, the machining contents are reasonably divided into two processes of the front face and the back face, and short cutters with good rigidity are used for boring, so that the cutter cost is reduced, and the surface quality influence caused by long cutter vibration is eliminated.

Description

Technical Field

[0001] This invention specifically relates to a method for machining a traction machine frame based on a CNC milling machine. Background Technology

[0002] In the wire and cable manufacturing industry, the tracked traction machine is one of the core pieces of equipment in the production line. Its function is to smoothly drag the wire and cable from the unloading end to the take-up end at a specific speed, and to complete the cable sheathing, armoring and wrapping processes in the process. The blank of the tracked traction machine frame is usually a welded structural component with many and complex processing elements. It mainly includes: the bearing cover mounting surface and bearing hole, clamping cylinder mounting surface and bolt hole, tension shaft hole boss surface and tension shaft hole on the front, as well as the bearing cover mounting surface and bearing hole, tension shaft hole boss surface and tension shaft hole on the back, and also the bottom surface of the frame.

[0003] In CNC milling, to complete the machining of holes and surfaces distributed on different planes, it is often necessary to flip and re-clamp the workpiece multiple times. This multiple clamping method not only increases auxiliary time and leads to low machining efficiency, but more importantly, each clamping introduces new positioning errors, making it difficult to unify the datum and ultimately making it difficult to stably guarantee the strict form and position tolerance requirements between various machining elements. In addition, when machining back holes, if an extended tool is used in the front clamping state, the long overhanging tool is prone to vibration. Therefore, we propose a method for machining the traction machine frame based on CNC milling. Summary of the Invention

[0004] The purpose of this invention is to provide a method for machining a traction machine frame based on a CNC milling machine, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for machining a traction machine frame based on a CNC milling machine, comprising the following steps:

[0006] First process: The blank of the machine frame is clamped on the worktable of the CNC gantry milling machine with the back facing down. It is corrected and positioned. In one clamping state, the milling of the bearing cover mounting surface, clamping cylinder mounting surface and tension shaft hole boss surface on the front of the machine frame is completed in sequence. The drilling of the tension shaft hole and clamping cylinder bolt hole on the front is completed. The boring of the bearing hole and tension shaft hole on the front is completed. The bottom surface of the machine frame is milled using a side milling head.

[0007] The second process involves flipping the frame that has completed the first process over and clamping it onto the worktable of the CNC gantry milling machine with its front facing down. Using the front feature elements that have been machined in the first process as the positioning reference, the milling of the bearing cover mounting surface and the tension shaft hole boss surface on the back of the frame is completed in sequence during a single clamping operation. The drilling of the tension shaft hole on the back is also completed, as well as the boring of the bearing hole and the tension shaft hole on the back.

[0008] Preferably, the first process includes the following steps:

[0009] Step 1: Place the frame face down on the left and right clamps, align the top surface of the frame, find the midpoints of the upper and lower bearing holes and the upper and lower tensioning shaft holes, use the rear support pin and the right support pin to position the frame, and clamp the front of the frame with the pressure plate.

[0010] Step 2: Rough mill and finish mill the front bearing cover mounting surface and the front tensioning shaft hole boss surface; rough mill and finish mill the clamping cylinder mounting surface.

[0011] Step 3: Drill the positioning holes for the clamping cylinder bolts, and drill the bottom hole and positioning hole for the front tensioning shaft.

[0012] Step 4: Rough mill the tensioning shaft hole and bearing hole on the front side, and leave allowance for fine boring;

[0013] Step 5: Precision boring the front tension shaft hole and the front bearing hole, and rough milling and finish milling the bottom surface of the machine frame using the side milling head.

[0014] Preferably, the second process includes the following steps:

[0015] Step 6: Place the frame face down, using the front tensioning shaft hole boss surface, the front bearing cover mounting surface, and the front upper and lower bearing holes processed in the first process as positioning references. Use the rear support pin and the right support pin for auxiliary support, and clamp the back of the frame with the pressure plate.

[0016] Step 7: Rough milling and finish milling the back bearing cap mounting surface and the back tensioning shaft hole boss surface;

[0017] Step 8: Drill the bottom hole and positioning hole of the tensioning shaft on the back;

[0018] Step 9: Rough mill the tensioning shaft hole and bearing hole on the back side, and leave allowance for fine boring;

[0019] Step 10: Precision boring of the back tensioning shaft hole and bearing hole.

[0020] Preferably, the frame clamping method in both the first and second processes is a flat clamping method.

[0021] Preferably, the processing of the first and second processes ensures that the coaxiality of the bearing holes and tensioning shaft holes on the front and back of the frame meets the preset accuracy requirements.

[0022] Preferably, the frame blank is a welded structural component.

[0023] Preferably, the positioning of the first and second processes is achieved by using two types of pins on the same side to ensure the form and position tolerance accuracy between the processed elements on the back and the processed elements on the front.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] The first step of this invention completes the machining of all front and bottom surface elements in one clamping, avoiding the conversion error of the positioning datum. The second step uses the precision surface and hole already machined in the first step as the datum, and uses the positioning method of two positioning pins on the same surface to perform back-side machining, effectively ensuring the strict parallelism and coaxiality requirements between the front and back surfaces, improving machining accuracy. The machining content is reasonably divided into two processes, front and back, and each process is boring with a short tool with good rigidity, avoiding the use of extra-long tools to accommodate both front and back surface machining. This reduces tool costs and eliminates the surface quality risk caused by the vibration of long tools. In addition, the flat clamping method is used during the machining process, which makes the workpiece clamping quick and stable, reducing the time for auxiliary alignment. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the front clamping structure of the frame of the present invention;

[0027] Figure 2 This is a schematic diagram of the frame back clamping structure of the present invention;

[0028] Figure 3 This is a schematic diagram of the right support pin and the frame mating structure of the present invention;

[0029] Figure 4 This is a schematic diagram of the existing machine frame to be processed;

[0030] Figure 5 A schematic diagram showing the effect of the bearing holes in the existing machine frame to be processed;

[0031] Figure 6 This is a schematic diagram of the existing rack layout.

[0032] In the diagram: 1. Frame; 201. Front bearing cap mounting surface; 202. Clamping cylinder mounting surface; 203. Front tensioning shaft hole boss surface; 204. Bearing hole; 206. Tensioning shaft hole; 208. Rear bearing cap mounting surface; 209. Rear tensioning shaft hole boss surface; 210. Frame bottom surface; 211. Clamping cylinder bolt hole; 212. Frame top surface; 301. Left clamp; 302. Right clamp; 303. Rear support pin; 304. Right support pin; 305. Pressure plate; 401. Cylindrical pin; 402. Diamond pin. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see Figures 1-6 The present invention provides a technical solution: a method for machining a traction machine frame based on a CNC milling machine, comprising the following steps:

[0035] First step: Place the machine frame blank 1 face down on the left clamp 301 and right clamp 302 of the worktable. First, level the top surface 212 of the machine frame. Then, use a dial indicator or edge finder to find the midpoint of the upper and lower bearing holes 204 and the midpoint of the upper and lower tension shaft holes 206. After positioning, use the rear support pin 303 and the right support pin 304 of the clamp to abut against the corresponding reference edge or surface of the machine frame for precise positioning. Finally, use the pressure plate 305 to press the non-machined area on the front of the machine frame to complete the clamping.

[0036] In this clamping state, the CNC gantry milling machine performs machining according to the following sequence of steps:

[0037] Use a face milling cutter to rough and finish mill the front bearing cover mounting surface 201 and the front tensioning shaft hole boss surface 203 to achieve the flatness and surface roughness required by the drawing. Rough and finish mill the clamping cylinder mounting surface 202 to ensure the perpendicularity of the surface to the datum.

[0038] Use a center drill or short drill bit to drill the clamping cylinder bolt hole 211 positioning hole, the front tensioning shaft hole 206 bottom hole and its positioning hole;

[0039] Use a boring bar or a large-diameter milling cutter to rough mill the front tensioning shaft hole 206 using helical interpolation or circumferential interpolation, leaving a fine boring allowance of 0.3mm to 0.5mm. Use helical interpolation or circumferential interpolation to rough mill the front bearing hole 204, leaving a fine boring allowance of 0.3mm to 0.5mm.

[0040] Use a precision boring tool to precision bore the front tensioning shaft hole 206 and the front bearing hole 204 to achieve the final dimensional tolerances and surface roughness required by the drawing.

[0041] Call the side milling head attachment configured on the machine tool, rotate the spindle head to the horizontal direction, and perform rough milling and finish milling on the bottom surface 210 of the frame to ensure the parallelism and distance dimensional tolerance between the bottom surface and the center lines of each shaft hole.

[0042] Second step: Rotate the frame 1, which has completed the first step, 180 degrees so that the finished front side is facing down. At this time, the front tensioning shaft hole boss surface 203 and the front bearing cover mounting surface 201, which have been precision machined in the first step, are used as the main positioning reference planes. Cylindrical pins 401 and diamond pins are inserted into the precision machined front bearing hole 204 and front tensioning shaft hole 206, respectively, to achieve precise positioning on the same surface using two types of pins. The rear support pin 303 and the right support pin 304 abut against the side of the frame as auxiliary support to prevent processing vibration. Finally, the pressure plate 305 is used to press the non-processed area on the back of the frame.

[0043] In this clamping state, the CNC gantry milling machine performs machining according to the following sequence of steps:

[0044] Use a face milling cutter to rough and finish mill the bearing cover mounting surface 208 and the tensioning shaft hole boss surface 209 on the back side.

[0045] Use a center drill or short drill bit to drill the bottom hole of the tensioning shaft hole 206 on the back and its positioning hole;

[0046] Use a boring bar or a large-diameter milling cutter to rough mill the tensioning shaft hole 206 and the bearing hole 204 on the back side, and leave a fine boring allowance;

[0047] Use a precision boring tool to perform precision boring on the tension shaft hole 206 and the bearing hole 204 on the back side.

[0048] like Figure 6The diagram shows an existing frame. One end of the front surface of the traction machine frame 5 has a traction wheel 6, and the other end has a tensioning wheel 8. Rubber tracks 7 are mounted on the traction wheel 6 and tensioning wheel 8. The middle of the front surface of the traction machine frame 5 has a clamping assembly 9 that pushes the rubber tracks 7 to move, thereby achieving a clamping engagement between the rubber tracks 7 and the cable. This invention, through the above method, utilizes the multi-axis linkage and side milling head function of a CNC gantry milling machine. By scientifically dividing the processing steps and strictly adhering to the principle of unified benchmarks, it achieves high-precision integrated processing of complex welded structural parts. Verification shows that the parallelism error between the upper and lower bearing holes and between the upper and lower tensioning shaft holes of the frame processed using this method can be stably controlled within 0.02mm, and the coaxiality error between the front and back bearing holes can be stably controlled within φ0.02mm, fully meeting the high-precision transmission requirements of the tracked traction machine. Furthermore, the processing efficiency is improved by approximately 30% or more compared to the traditional multi-clamping process.

[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for processing a traction machine frame based on a numerical control milling machine, characterized in that, Includes the following steps: First process: The blank of the machine frame is clamped on the worktable of the CNC gantry milling machine with the back facing down. It is corrected and positioned. In one clamping state, the milling of the bearing cover mounting surface, clamping cylinder mounting surface and tension shaft hole boss surface on the front of the machine frame is completed in sequence. The drilling of the tension shaft hole and clamping cylinder bolt hole on the front is completed. The boring of the bearing hole and tension shaft hole on the front is completed. The bottom surface of the machine frame is milled using a side milling head. The second process: The frame that has completed the first process is flipped over and clamped on the worktable of the CNC gantry milling machine with its front facing down. The front feature elements that have been machined in the first process are used as the positioning reference. In one clamping state, the milling of the bearing cover mounting surface and the tension shaft hole boss surface on the back of the frame are completed in sequence, the drilling of the tension shaft hole on the back is completed, and the boring of the bearing hole and the tension shaft hole on the back is completed. The first process includes the following steps: Step 1: Place the frame face down on the left and right clamps, align the top surface of the frame, find the midpoints of the upper and lower bearing holes and the upper and lower tensioning shaft holes, use the rear support pin and the right support pin to position the frame, and clamp the front of the frame with the pressure plate. Step 2: Rough mill and finish mill the front bearing cover mounting surface and the front tensioning shaft hole boss surface; rough mill and finish mill the clamping cylinder mounting surface. Step 3: Drill the positioning holes for the clamping cylinder bolts, and drill the bottom hole and positioning hole for the front tensioning shaft. Step 4: Rough mill the tensioning shaft hole and bearing hole on the front side, and leave allowance for fine boring; Step 5: Precision boring the front tensioning shaft hole and the front bearing hole, and rough milling and finish milling the bottom surface of the machine frame using the side milling head; The second process includes the following steps: Step 6: Place the frame face down, using the front tensioning shaft hole boss surface, the front bearing cover mounting surface, and the front upper and lower bearing holes processed in the first process as positioning references. Use the rear support pin and the right support pin for auxiliary support, and clamp the back of the frame with the pressure plate. Step 7: Rough milling and finish milling the back bearing cap mounting surface and the back tensioning shaft hole boss surface; Step 8: Drill the bottom hole and positioning hole of the tensioning shaft on the back; Step 9: Rough mill the tensioning shaft hole and bearing hole on the back side, and leave allowance for fine boring; Step 10: Precision boring of the tensioned shaft hole and bearing hole on the back side.

2. The method for processing the frame of a traction machine based on a numerical control milling machine according to claim 1, characterized in that: The frame clamping method in both the first and second processes is a flat clamping method.

3. The method of claim 1, wherein: The first and second processing steps ensure that the coaxiality of the bearing holes and tensioning shaft holes on the front and back of the frame meets the preset accuracy requirements.

4. The method of claim 1, wherein: The frame blank is a welded structural component.

5. The method of claim 1, wherein: The positioning of the first and second processes is achieved by using two types of pins on the same side to ensure the form and position tolerance accuracy between the processed elements on the back and the processed elements on the front.

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