A drilling and milling combined machine tool for high-precision processing of silica sol castings

Abstract

This application relates to a drilling and milling composite machine tool for high-precision machining of silica sol castings. It includes a machine body with a first axially penetrating central hole inside its spindle unit; a drilling and milling composite tool detachably mounted on the spindle unit of the machine body, the tool having a second central hole communicating with the first central hole, and a spiral chip removal groove on its outer surface; and an atomizing cooling system integrated within the first central hole, comprising a coolant supply channel, an atomizer generator, and an atomizing spray channel connected in sequence, wherein the atomizing spray channel is coaxially connected to the first central hole, allowing the coolant to be atomized and delivered to the cutting zone via the first and second central holes. This application enables the coolant to reach the cutting zone, ensuring the quality of hole forming.

Description

Technical Field

[0001] This application relates to the technical field of drilling and milling composite machine tools, and in particular to a drilling and milling composite machine tool for high-precision machining of silica sol castings. Background Technology

[0002] Silica sol castings are widely used in aerospace, medical devices, and other fields due to their high precision and good surface quality. However, these castings have the following characteristics: the material is hard but brittle, making it prone to microcracks during machining; they have complex structures, often featuring deep holes and thin walls; they require high dimensional accuracy; and they have strict surface roughness requirements. To balance machining quality and efficiency for silica sol castings, drilling and milling combined machine tools are often used for processing.

[0003] When using a drilling and milling machine to perform deep hole drilling on silica sol castings, traditional casting cooling is difficult to reach the cutting zone, resulting in poor chip removal, increased tool wear, and decreased hole quality. Summary of the Invention

[0004] In order to overcome the technical problems described in the prior art, this application provides a drilling and milling composite machine tool for high-precision machining of silica sol castings.

[0005] This application provides a drilling and milling composite machine tool for high-precision machining of silica sol castings, which adopts the following technical solution: A drilling and milling composite machine tool for high-precision machining of silica sol castings, comprising: The machine tool body has an axially penetrating first central hole inside its spindle unit; A drilling and milling compound tool is detachably mounted on the spindle unit of the machine tool body. The drilling and milling compound tool has a second center hole that communicates with the first center hole, and the outer surface of the drilling and milling compound tool is provided with a spiral chip removal groove. The atomizing cooling system, integrated within the first central hole, includes a coolant supply channel, an atomizer, and an atomizing spray channel connected in sequence. The atomizing spray channel is coaxially connected to the first central hole, allowing the coolant to be atomized and then transported to the cutting zone via the first and second central holes.

[0006] Furthermore, the atomizing jet channel is provided with a Venturi acceleration section, and a spiral guide vane is provided on the inner wall of the first central hole. The spiral guide vane is located on the side of the Venturi acceleration section near the second central hole.

[0007] Furthermore, the spiral guide vane is provided in four pieces, which are evenly distributed circumferentially and segmented axially within the first central hole.

[0008] Furthermore, the surface of the spiral chip removal groove is provided with multiple hemispherical pits, the diameter of which is 50-100μm.

[0009] Furthermore, the surface of the spiral chip removal groove is coated with a diamond-like coating.

[0010] Furthermore, the coolant is a water-based solution containing 5%-8% nano-alumina particles, with 0.1%-0.3% surfactant added to the water-based solution. The water-based solution also contains a mixture of compressed air and nitrogen, with a volume ratio of 3:1 between compressed air and nitrogen.

[0011] Furthermore, the connection between the spindle unit and the drilling and milling composite tool is sealed by an airtight ring.

[0012] Furthermore, the front end of the spindle unit is equipped with an infrared temperature measurement module for monitoring the temperature of the cutting zone, and the machine tool body is equipped with an adaptive control module. Both the infrared temperature measurement module and the atomizing generator are electrically connected to the adaptive control module, so that the adaptive control module can dynamically adjust the atomization cooling parameters according to temperature changes and maintain the temperature of the cutting zone in the range of 80-120℃.

[0013] In summary, the beneficial technical effects of this application are as follows: the development of an embedded atomizing cooling system in the spindle unit delivers atomized coolant through the first central hole, and the spiral chip removal groove design on the outer surface of the drilling and milling composite tool achieves forced chip removal, breaking through the limitations of traditional external cooling methods and solving the cooling problem in deep hole machining. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application.

[0015] Figure 2 This is a schematic diagram of the structure of the spindle unit, drilling and milling composite tool, spiral chip removal groove, hemispherical recess, airtight ring and infrared temperature measurement module in the embodiments of this application.

[0016] Figure 3 This is a cross-sectional structural diagram of the spindle unit and the drilling-milling composite tool in the embodiments of this application.

[0017] Reference numerals: 1. Machine tool body; 2. Spindle unit; 3. First center hole; 4. Drilling and milling compound tool; 5. Second center hole; 6. Spiral chip removal groove; 7. Coolant supply channel; 8. Atomizer; 9. Atomizing spray channel; 10. Venturi acceleration section; 11. Spiral guide vane; 12. Hemispherical recess; 13. Airtight ring; 14. Infrared temperature measurement module; 15. Adaptive control module. Detailed Implementation

[0018] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] This application discloses a drilling and milling composite machine tool for high-precision machining of silica sol castings. (Refer to...) Figure 1 , Figure 2 and Figure 3 A high-precision drilling and milling composite machine tool for machining silica sol castings includes a machine tool body 1, a drilling and milling composite tool 4, and an atomizing cooling system. The drilling and milling composite tool 4 is detachably mounted on the spindle unit 2 of the machine tool body 1. The connection between the spindle unit 2 and the drilling and milling composite tool 4 is sealed by an airtight ring 13, so that the machine tool body 1 can drive the drilling and milling composite tool 4 to rotate and translate along the X-axis, Y-axis, and Z-axis through the spindle unit 2, so that the drilling and milling composite tool 4 can both mill the workpiece and drill holes in the workpiece.

[0020] Reference Figure 1 , Figure 2 and Figure 3The machine tool body 1 has a first central hole 3 that extends axially through the spindle unit 2, and a second central hole 5 inside the drilling and milling compound tool 4. The outer surface of the drilling and milling compound tool 4 has a spiral chip removal groove 6. When the drilling and milling compound tool 4 is installed at the front end of the spindle unit 2, the first central hole 3 and the second central hole 5 are coaxially connected. When the drilling and milling compound tool 4 performs deep hole drilling on the workpiece, the spiral chip removal groove 6 can transport and discharge chips from the cutting zone to the outside of the deep hole. In this embodiment, the spiral angle β of the spiral chip removal groove 6 is 35°~45°, the ratio of the groove depth h to the diameter D of the drilling and milling compound tool 4 is h / D=0.15~0.25, and the radius of the bottom arc r is 0.2h~0.3h. The spiral chip removal groove 6 with these parameters can achieve a balance between chip removal efficiency and the strength of the drilling and milling compound tool 4, making it particularly suitable for chip removal from silica sol materials, reducing chip removal resistance by more than 40%. The atomizing cooling system is integrated within the first central hole 3. A housing for supplying coolant to the atomizing cooling system is located on one side of the machine tool body 1. The coolant within the housing is a water-based solution containing 5%-8% nano-alumina particles. 0.1%-0.3% surfactant is added to the water-based solution, along with a mixture of compressed air and nitrogen at a volume ratio of 3:1. The nanofluid can improve heat exchange efficiency by over 50%, nitrogen can inhibit high-temperature oxidation of silica sol, and the surfactant improves droplet wettability. When the machine tool body 1 drives the drilling and milling composite tool 4 to perform deep hole drilling on the workpiece via the spindle unit 2, the atomizing cooling system performs high-pressure atomization of the coolant within the housing. The atomized coolant droplets are then sequentially transported to the cutting zone via the first central hole 3 and the second central hole 5. This achieves efficient cooling of the cutting zone while accelerating the movement of chips along the spiral chip removal groove 6 out of the deep hole, forming a synergistic mechanism of fluid chip removal, significantly improving chip removal efficiency and tool life.

[0021] Reference Figure 1 , Figure 2 and Figure 3 The atomizing cooling system includes a coolant supply channel 7, an atomizer 8, and an atomizing spray channel 9 connected in sequence. The atomizer 8 is fixed inside the first central hole 3, and the atomizing spray channel 9 is coaxially connected to the first central hole 3. The atomizer 8 includes a vortex chamber and an ultrasonic atomizing head. The coolant supply channel 7 is located at the inlet end of the vortex chamber. The coolant in the chamber is connected to the coolant supply channel 7 through a pipe, allowing the coolant in the chamber to smoothly reach the vortex chamber and form a swirling flow. The ultrasonic atomizing head is fixed at the outlet end of the vortex chamber. The ultrasonic atomizing head can break the coolant into micron-sized droplets. Using a two-stage atomization mechanism of vortex and ultrasound, it can produce uniform droplets with a particle size of 5-10 μm. Compared with traditional atomization methods, the atomization efficiency is increased by more than 30%, and the coolant permeability is significantly enhanced.

[0022] For the setting of atomizing spray channel 9, refer to... Figure 3 The atomizing injection channel 9 is equipped with a Venturi acceleration section 10, with a contraction ratio of 1:4 to 1:6. The Venturi acceleration section 10 can accelerate the coolant droplets to 50-80 m / s. A spiral guide vane 11 is provided on the inner wall of the first central hole 3. The spiral guide vane 11 is located on the side of the Venturi acceleration section 10 near the second central hole 5. The spiral guide vane 11 imparts swirling characteristics to the coolant droplets, ensuring that the coolant droplets are evenly distributed within the second central hole 5 and preventing the coolant droplets from accumulating during long-distance transport. According to fluid dynamics simulations, the number of spiral guide vanes 11 is 3-6. In this embodiment, four spiral guide vanes 11 are provided, circumferentially distributed and axially segmented within the first central hole 3. The four spiral guide vanes 11 can create a stable spiral flow field for the coolant droplets.

[0023] To achieve thermal stability control during the processing, refer to Figure 2 and Figure 3 An infrared temperature measurement module 14 for monitoring the temperature of the cutting zone is installed at the front end of the spindle unit 2. The infrared temperature measurement module 14 is ring-shaped and coaxially fixed at the end of the spindle unit 2. An adaptive control module 15 is installed on the machine tool body 1. The infrared temperature measurement module 14 and the atomizing generator 8 are both electrically connected to the adaptive control module 15, enabling the adaptive control module 15 to dynamically adjust the atomization cooling parameters according to temperature changes, maintaining the temperature of the cutting zone within the range of 80-120℃. Closed-loop temperature control can avoid thermal damage to the silica sol material, improving surface quality consistency by 60%.

[0024] Reference Figure 2 and Figure 3 The surface of the spiral chip removal groove 6 is provided with multiple hemispherical recesses 12, each with a diameter of 50-100 μm. Since the size of silica sol chips is mostly 200-500 μm, the silica sol chips do not accumulate in the hemispherical recesses 12 during the chip removal process. Instead, the micro-texture formed by the multiple hemispherical recesses 12 creates an air cushion effect, where the micro-vortices within the recesses generate an upward lift component, thus reducing chip removal friction. To prevent wear on the spiral chip removal groove 6 caused by chips, its surface is coated with a diamond-like carbon (DLC) coating. This DLC coating significantly improves the wear resistance of the spiral chip removal groove 6, extending the life of the drilling and milling composite tool 4 by 3-5 times.

[0025] The implementation principle of a high-precision drilling and milling composite machine tool for machining silica sol castings according to an embodiment of this application is as follows: The machine tool body 1 drives the drilling and milling composite tool 4 to rotate and translate along the X, Y, and Z axes via the spindle unit 2, enabling the drilling and milling composite tool 4 to both mill and drill the workpiece. During deep hole drilling, the atomization cooling system is activated, allowing the atomized coolant droplets to be sequentially transported to the cutting zone through the first center hole 3 and the second center hole 5, achieving efficient cooling of the cutting zone. Simultaneously, as the drilling and milling composite tool 4 rotates, chips in the cutting zone can move outward along the spiral chip removal groove 6, forming a synergistic mechanism of fluid chip removal, significantly improving chip removal efficiency and tool life.

[0026] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A drilling and milling composite machine tool for high-precision machining of silica sol castings, characterized in that, include The machine tool body (1) has an axially penetrating first central hole (3) inside its spindle unit (2); The drilling and milling composite tool (4) is detachably mounted on the spindle unit (2) of the machine tool body (1). The drilling and milling composite tool (4) has a second center hole (5) that communicates with the first center hole (3) inside. The outer surface of the drilling and milling composite tool (4) is provided with a spiral chip removal groove (6). The atomizing cooling system is integrated into the first central hole (3) and includes a coolant supply channel (7), an atomizer (8) and an atomizing spray channel (9) connected in sequence. The atomizing spray channel (9) is coaxially connected to the first central hole (3), so that the coolant is atomized and transported to the cutting zone through the first central hole (3) and the second central hole (5).

2. The drilling and milling composite machine tool for high-precision machining of silica sol castings according to claim 1, characterized in that, The atomizing jet channel (9) is provided with a Venturi acceleration section (10), and a spiral guide vane (11) is provided on the inner wall of the first central hole (3). The spiral guide vane (11) is located on the side of the Venturi acceleration section (10) near the second central hole (5).

3. The drilling and milling composite machine tool for high-precision machining of silica sol castings according to claim 2, characterized in that, The spiral guide vane (11) is provided in four pieces, which are evenly distributed circumferentially and segmented axially within the first central hole (3).

4. The drilling and milling composite machine tool for high-precision machining of silica sol castings according to claim 1, characterized in that, The surface of the spiral chip removal groove (6) is provided with a plurality of hemispherical pits (12), the diameter of which is 50-100μm.

5. A drilling and milling composite machine tool for high-precision machining of silica sol castings according to claim 4, characterized in that, The surface of the spiral chip removal groove (6) is coated with a diamond-like coating.

6. A drilling and milling composite machine tool for high-precision machining of silica sol castings according to claim 1, characterized in that, The coolant is a water-based solution containing 5%-8% nano-alumina particles. 0.1%-0.3% surfactant is added to the water-based solution. The water-based solution also contains a mixture of compressed air and nitrogen, with a volume ratio of 3:

1.

7. A drilling and milling composite machine tool for high-precision machining of silica sol castings according to claim 1, characterized in that, The connection between the spindle unit (2) and the drilling and milling composite tool (4) is sealed by an airtight ring (13).

8. A drilling and milling composite machine tool for high-precision machining of silica sol castings according to claim 1, characterized in that, The spindle unit (2) is equipped with an infrared temperature measurement module (14) for monitoring the temperature of the cutting zone at its front end. The machine tool body (1) is equipped with an adaptive control module (15). The infrared temperature measurement module (14) and the atomizing generator (8) are electrically connected to the adaptive control module (15), so that the adaptive control module (15) can dynamically adjust the atomizing cooling parameters according to the temperature change and maintain the temperature of the cutting zone in the range of 80-120℃.

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