A method for suppressing intersecting burrs in cross holes using variable path and variable parameter helical milling

Abstract

This invention relates to a method for suppressing intersecting burrs in cross-holes using variable-path, variable-parameter helical milling. The method mainly includes the following steps: performing variable-path helical milling to form a single-step hole with a reaming allowance at the intersection of the cross-holes; and then performing variable-parameter helical milling to enlarge the resulting stepped hole, continuously reducing the burr size by progressively decreasing the removal amount, ultimately obtaining a cross-hole without intersecting burrs. This invention uses helical milling instead of drilling, primarily to change the burr formation mechanism from a cutting perspective, significantly reducing the burr size. Furthermore, the variable-path, variable-parameter method uses the previous burr size as a reference; during the reaming process, the removal amount decreases, and the burr size decreases until it is completely suppressed. The method proposed in this invention can achieve cross-hole burr-free operation, effectively saving labor costs, improving production efficiency, and being more environmentally friendly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of burr suppression, and in particular to a method for suppressing intersecting hole through burrs by variable path and variable parameter spiral milling. BACKGROUND

[0002] Multi-channel precision parts are commonly used in the fields of aerospace, electronics and electrical appliances, hydraulic servo equipment, etc. and are widely applied. Taking a common multi-channel servo valve as an example, since the multi-channel valve has a multi-intersecting hole structure inside, intersecting hole through burrs will be generated after the intersecting holes are drilled and milled. The existence of the burrs will reduce the quality of the inner hole and seriously affect the safety of the system. Moreover, the intersecting hole through part is usually narrow and deep, and it is very difficult to remove. The intersecting hole through burr of the multi-channel precision part is an urgent problem to be solved in the industry.

[0003] At present, the method for removing the burrs is still mainly a passive burr removal process, including manual removal, electrolytic removal, abrasive flow removal, ultrasonic vibration removal and laser removal, etc. The manual removal of the burrs mainly uses a brush and a scraper to manually clean the burrs. This method has high labor cost and low production efficiency. It is extremely difficult to design a special burr removal tool for a long and narrow intersecting hole. Moreover, the burr removal quality is unstable. The electrolytic removal of the burrs has very high requirements for the cathode and needs to strictly control the electrolytic parameters to avoid damaging the workpiece. The obvious shortcomings are obvious. The abrasive flow removal of the burrs is to push the burrs out by a cylinder containing abrasive viscous fluid. This method has poor effect on the removal of the intersecting hole through burrs. Moreover, the viscous fluid cannot be discharged in a long and narrow intersecting hole. The ultrasonic vibration is only suitable for removing very fine burrs on the hole wall surface. The laser removal of the burrs is to remove the burrs by high heat generated by the laser. The disadvantage is that the burrs need to be removed one by one, and the efficiency is extremely low. In addition, whether it is the burr removal process itself (such as abrasive flow and electrolysis) or the small metal burr debris removed, it will pollute the environment.

[0004] In summary, for the intersecting hole through burrs in the narrow and long part of the multi-channel precision part, the existing technology adopts the method of adding a burr removal process to solve the problem, which seriously hinders the development process of the automatic and unmanned production of the parts. Moreover, there is no burr removal method that can efficiently, environmentally and high-quality remove the intersecting hole through burrs. SUMMARY

[0005] The purpose of the present application is to provide a method for suppressing intersecting hole through burrs by variable path and variable parameter spiral milling, which can actively suppress the intersecting hole through burrs from the source and replace the passive removal in the later stage, thereby greatly improving the production efficiency of the multi-channel valve and reducing the labor cost.

[0006] The technical scheme adopted by the present application is as follows:

[0007] The method for inhibiting the intersecting hole through burr by variable path and variable parameter spiral milling comprises the following steps.

[0008] S1: clamp the spiral milling cutter on the eccentric milling head, lock and fix the eccentric milling head on the main shaft of the numerical control machine tool by using the locking screw, and clamp and fix the workpiece on the opposite side of the spiral milling cutter;

[0009] S2: adjust the position of the eccentric milling head and move it to the corresponding position to be machined;

[0010] S3: variable path spiral milling hole, that is, before the through hole is formed, the radius of the spiral feed track is contracted, the hole diameter is reduced, and then the feed is continued until the intersecting through hole is formed, and a stepped hole with an expanded hole allowance is formed;

[0011] S4: variable parameter spiral milling of the stepped hole obtained by variable path spiral milling is performed, the removal amount of the hole expansion is gradually reduced, the burr generated by each hole expansion is also reduced, and the burr generated by the last hole expansion is removed in the next hole expansion process; after continuously reducing the removal amount by variable parameter, the removal amount of the last hole expansion is very thin, and no burr is generated, and finally the intersecting hole without burr is obtained.

[0012] Further, in the step S1, the model of the spiral milling cutter is selected according to the size and accuracy of the hole to be machined.

[0013] Further, in the steps S2 and S3, the movement track of the spiral milling cutter needs to be programmed and preset, and the milling cutter feeds according to the preset track, and the maximum value of the radius of the feed track is the radius of the vertical hole.

[0014] Further, after the step S4, an endoscope camera is used to check the formation of the hole burr on site.

[0015] Compared with the prior art, the present application has the following beneficial effects:

[0016] 1. The method for inhibiting the intersecting hole through burr by variable path and variable parameter spiral milling discards the passive removal method after the burr is generated in the existing machining process, actively inhibits the formation of the burr from the source in the machining process, instead of the later removal, which is not only beneficial to obtain high-quality multi-channel precision part products with inner holes, but also beneficial to improve the production efficiency, reduce the labor cost and environmental pollution.

[0017] 2, The method for inhibiting the intersecting hole through-wall burr by the variable path and variable parameter helical milling of the application adopts the helical milling mode to replace the drilling, changes the burr forming mode, converts the drilling tearing burr into the minimum Poisson burr, greatly reduces or even eliminates the burr; meanwhile, the helical milling mode replaces the drilling, the cutting force is small, the cutting temperature is low, and the chip removal and heat dissipation during the machining process are better, which is beneficial to improve the hole machining quality.

[0018] 3, The method for inhibiting the intersecting hole through-wall burr by the variable path and variable parameter helical milling of the application forms the stepped hole and then expands the hole through the variable path and variable parameter mode, and the removal amount is reduced constantly with the previous burr forming size as the reference, so that the formed burr is smaller and smaller until the burr is completely inhibited. The application can realize the intersecting hole machining without the through-wall burr, is beneficial to greatly improve the quality of the inner hole of the multi-channel precision part, especially the intersecting hole through-wall part, and has the advantages of high production efficiency, low labor cost, environmental protection and the like. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the application object of the application, and is a schematic diagram of the intersecting hole of a multi-channel part;

[0020] Figure 2 is a schematic diagram of the outlet burr formed in the drilling process of the drilling hole;

[0021] Figure 3 is a schematic diagram of the outlet burr formed in the helical milling hole process;

[0022] Figure 4 is a schematic diagram of the variable path helical milling hole step of the application;

[0023] Figure 5 is a schematic diagram of the variable parameter helical milling hole step of the application;

[0024] Figure 6 is a schematic diagram of the variable path helical milling hole path of the application;

[0025] Figure 7 is a schematic diagram of the variable parameter helical milling hole path of the application;

[0026] Figure 8 is a schematic diagram of the intersecting hole drilling effect in the application;

[0027] Figure 9 is a schematic diagram of the helical milling intersecting hole effect in the application. DETAILED DESCRIPTION

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required by the embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0029] The method for inhibiting the intersecting hole through burr by changing the path and the parameter of the spiral milling, as shown in Figures 1 to 7 The specific implementation process is as follows:

[0030] S1: The spiral milling cutter is clamped on the eccentric milling head, the eccentric milling head is locked and fixed on the spindle of the numerical control machine tool by using the locking screw, and the workpiece is clamped and fixed on the opposite side of the spiral milling cutter; wherein the model of the spiral milling cutter is selected according to the size and accuracy of the hole to be machined.

[0031] S2: Adjust the position of the eccentric milling head, move it to the corresponding position to be machined, and the spiral milling cutter can be made to rotate simultaneously by the numerical control machine tool and the eccentric milling head; start the spindle, push the milling cutter along the axial direction to the outer surface of the workpiece through the numerical control machine tool, record the coordinate position when the two are in contact, complete the tool setting, and prepare for spiral milling hole processing.

[0032] S3: Change the path of spiral milling hole, first, according to the radius of the vertical hole to be machined as the feed trajectory radius, spiral milling hole, when the feed is deep enough and the vertical hole is not penetrated, change the feed path, that is, before the through hole is formed, the radius of the spiral feed trajectory is contracted, the hole diameter is reduced, and then the feed is continued until the vertical hole is penetrated to form a cross through hole, forming a stepped hole with an expanded hole allowance.

[0033] The movement trajectory of the spiral milling cutter needs to be programmed and preset, and the milling cutter feeds according to the preset trajectory. The maximum value of the radius of the feed trajectory is the radius of the vertical hole.

[0034] S4: Perform variable parameter spiral milling hole expansion on the stepped hole obtained by variable path spiral milling. Based on the stepped hole processed in step S3, variable parameter spiral milling hole expansion is performed, and the radial depth of cut of the spiral milling cutter is reduced gradually. The burr produced by each hole expansion decreases with the decrease of the removal amount. The size of the burr produced by the last hole expansion is determined according to the size of the burr produced by the last hole expansion, so that the burr produced by the last hole expansion is removed in the next hole expansion process. After continuously changing the parameters to reduce the burr size and the removal amount, the removal amount of the last hole expansion is very thin, and no burr is produced after removal. Finally, the intersecting cross hole without burr is obtained.

[0035] After retracting the tool, the machine tool stops running, and the cross hole machining is completed. An endoscope camera probe is inserted into the cross hole on site to check whether the burr suppression at the intersection of the cross holes meets the requirements.

[0036] The working principle of this invention is as follows: First, it changes the formation method of burrs: Drilling produces tearing burrs, which are relatively large in size, while variable path and variable parameter spiral milling can transform tearing burrs into Poisson burrs. Among various types of burr formation, Poisson burrs are the smallest. By replacing drilling with spiral milling to process holes, the size of the burrs can be effectively and significantly reduced. In addition, compared with drilling, spiral milling also has advantages such as lower cutting force, easier chip removal, and better heat dissipation. Second, it uses a variable path and variable parameter method to process the hole: First, a single-step hole is formed by variable path spiral milling, and then the hole is enlarged by variable parameters. During the enlargement process, the size of the burr formed in the previous step is used as a reference, and the parameters are continuously changed to reduce the amount of material removed, thereby making the burrs smaller and smaller until they are completely suppressed.

[0037] All matters not covered in this invention are common knowledge.

[0038] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for suppressing burrs at the intersection of intersecting holes using variable path and variable parameter helical milling, characterized in that, The method comprises the following steps: S1: clamping the helical milling cutter on the eccentric milling head, locking and fixing the eccentric milling head on the main shaft of the numerical control machine tool using locking screws, and clamping and fixing the workpiece on the opposite side of the helical milling cutter; S2: adjusting the position of the eccentric milling head and moving it to the corresponding position to be processed, so that the helical milling cutter can simultaneously revolve and rotate by the numerical control machine tool and the eccentric milling head; turn on the main shaft, and push the milling cutter along the axial direction to the outer surface of the workpiece by the numerical control machine tool, record the coordinate position when the two are in contact, complete the tool setting, and prepare for helical milling hole processing; S3: variable-path helical milling hole, first helical milling hole according to the radius of the vertical hole to be processed as the feed track radius, when the vertical hole is not penetrated when the feed is deep enough, change the feed path, that is, before the through hole is formed, the radius of the helical feed track is contracted, the hole diameter is reduced, and then the feed is continued until the vertical hole is penetrated to form a cross through hole, forming a stepped hole with an expanded hole allowance; S4: variable-parameter helical milling of the stepped hole obtained by variable-path helical milling, gradually reducing the removal amount of the hole expansion, and the burr produced by each hole expansion is also reduced, and the burr produced by the last hole expansion is removed in the next hole expansion process; after continuously reducing the removal amount by changing the parameters, the removal amount of the last hole expansion is very thin, and no burr is produced, and finally a cross hole without burr is obtained.

2. The method of claim 1, wherein the method is characterized by: In step S1, the model of the helical milling cutter is selected according to the size and precision of the hole to be processed.

3. The method of claim 1, wherein the method is characterized by: In steps S2 and S3, the motion track of the helical milling cutter needs to be programmed and preset, and the milling cutter feeds according to the preset track, and the maximum radius of the feed track is the radius of the vertical hole.

4. The method of claim 1, wherein the method is characterized by: After step S4, use an endoscope camera to check the formation of burrs in the hole on site.

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