A numerical control slot milling device for precise automobile parts

Abstract

The application relates to the technical field of slot milling equipment, in particular to a numerical control slot milling device for automobile precision parts, which comprises a power tool holder and a tool bar, the tool bar is detachably connected with the power tool holder, the bottom of the power tool holder is provided with an expansion cylinder, a supporting ring for stabilizing the tool bar is arranged on the movable part of the expansion cylinder, the supporting ring is coaxially sleeved on the tool bar, and a ball spraying mechanism is arranged between the supporting ring and the tool bar; during the rotation of the tool bar, the balls on the ball spraying mechanism roll and coat the surface of the tool bar with cooling medium; the supporting ring is provided with a gas injection mechanism, and the gas injection mechanism is provided with two output parts. During the milling operation, the milling cutter head and the tool bar are continuously air-cooled, the balls continuously roll and coat the surface of the tool bar with cooling medium, the airflow promotes the volatilization of the cooling medium on the surface of the tool bar, the overall cooling efficiency of the tool bar is effectively improved, the overall temperature control effect of the milling cutter is optimized, and problems such as sharp tool wear and tool head melting and sticking of chips caused by high-temperature operation of the tool are avoided.

Description

Technical Field

[0001] This invention relates to the field of milling equipment technology, and more specifically to a CNC milling device for precision automotive parts. Background Technology

[0002] With the rapid development of the automotive lightweight and precision manufacturing industry, various automotive metal parts such as gearbox housings and brackets generally need to be formed and processed using CNC milling technology.

[0003] Existing CNC milling equipment for automotive parts mainly employs two cooling solutions: water spray cooling and compressed air cooling. However, both solutions have limitations. Firstly, some die-cast aluminum parts and powder metallurgy sintered parts have high porosity in their substrates. Direct spraying of cutting fluid can easily cause the medium to penetrate into the micropores of the workpiece, leading to blistering and coating peeling in subsequent processes. Therefore, large-scale water spray cooling is not feasible. Secondly, compressed air cooling relies on air convection for heat transfer, but the air heat transfer coefficient is low. Under the conditions of high-volume continuous high-speed milling of automotive parts, the heat dissipation capacity is insufficient. Long-term high-temperature operation of the milling cutter can easily cause problems such as edge softening and adhesive wear. Frequent tool changes not only increase the cost of tool consumables but also interrupt the production line cycle and reduce processing efficiency. Summary of the Invention

[0004] In view of the above situation and to overcome the defects of the prior art, the present invention provides a CNC milling device for precision automotive parts to solve the above problems.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A CNC milling device for precision automotive parts includes a power tool holder and a tool holder. The tool holder and the power tool holder are detachably connected. The bottom of the power tool holder is provided with a telescopic cylinder. A support ring for stabilizing the tool holder is provided on the movable part of the telescopic cylinder. The support ring is coaxially sleeved on the tool holder, and a ball spraying mechanism is provided between the two. During the rotation of the tool holder, the balls on the ball spraying mechanism roll and coat the surface of the tool holder with a cooling medium. The support ring is equipped with an air injection mechanism, which has two output sections. One output section is connected to the internal fluid of the telescopic cylinder, and the other output section is equipped with a solenoid valve, which is connected to the ball spray mechanism. When the solenoid valve is opened, the air injection mechanism injects air into the ball spray mechanism, causing the ball spray mechanism to spray water mist onto the outer surface of the tool holder.

[0006] Preferably, the power tool holder includes a tool holder body, a power element on the tool holder body and a cooling chamber inside, a heat exchange sleeve rotatably connected through the cooling chamber, the heat exchange sleeve is sleeved on the tool bar, and heat-conducting fins are provided on the heat exchange sleeve inside the cooling chamber. The end of the heat exchange sleeve is provided with an electric clamp for fixing the tool bar, and the output of the power element is connected to the electric clamp for driving. When the power element drives the electric clamp to rotate, it causes the tool holder and heat exchange sleeve to rotate.

[0007] Preferably, the telescopic cylinder includes an outer cylinder, which is installed at the bottom of the tool holder body. A movable cylinder is slidably fitted inside the outer cylinder. A spring is installed between the inner bottom wall of the movable cylinder and the bottom of the tool holder body. A support ring is fixedly installed at the end of the movable cylinder that extends out of the outer cylinder.

[0008] Preferably, the movable sleeve is disposed outside the cutter bar, and the support ring is provided with a ventilation opening.

[0009] Preferably, the movable cylinder is provided with a damping bearing, the damping bearing is provided with a first permanent magnet, and the power tool holder is provided with a second permanent magnet that matches the first permanent magnet. When the first permanent magnet is rotated so that the area corresponding to the second permanent magnet increases, the magnetic repulsion between the two increases, pushing the movable cylinder out of the outer cylinder.

[0010] Preferably, the ball spraying mechanism includes a mixing chamber formed inside the support ring and several flow channels, with the input end of the flow channels communicating with the fluid in the mixing chamber; The inner wall of the support ring is provided with several umbrella-shaped grooves. The output end of the flow channel is connected to the internal fluid of the umbrella-shaped groove. The ball is installed inside the umbrella-shaped groove. The support ring is provided with a limiting block for binding the ball.

[0011] Preferably, the input end of the mixing chamber is provided with a one-way valve, and the input end of the one-way valve is provided with a hose, the input end of the hose being in communication with the internal fluid of the cooling chamber.

[0012] Preferably, the gas injection mechanism includes a gas injection pipe mounted on a support ring. The input end of the gas injection pipe is equipped with an electric flow regulating valve. The gas injection pipe has two output ends, one of which is in communication with the fluid inside the movable cylinder. The input end of the solenoid valve is in communication with the fluid inside the other output end, and the output end of the solenoid valve is located inside the mixing chamber.

[0013] Preferably, the air injection pipe passes through the mixing chamber, and a solenoid valve is provided on the air injection pipe located inside the mixing chamber.

[0014] Preferably, the tool holder body is provided with a nozzle, the output direction of the nozzle is directed toward the milling cutter head, and the tool holder body is provided with a temperature sensor for monitoring the temperature of the milling cutter head. The electric flow regulating valve and the solenoid valve are both electrically connected to the temperature sensor.

[0015] The beneficial effects of this invention are as follows: 1. During the milling operation of this invention, the milling cutter head and cutter shank are continuously cooled by air, and the ball bearings continuously roll and coat the surface of the cutter shank with cooling medium. The airflow promotes the evaporation of the cooling medium on the surface of the cutter shank, effectively improving the overall cooling efficiency of the cutter shank, optimizing the overall temperature control effect of the milling cutter, and avoiding problems such as rapid tool wear and melting and sticking chips on the cutter head caused by high-temperature operation of the tool.

[0016] 2. During the milling operation of this invention, the heat generated by the milling cutter head is conducted along the cutter bar to the heat exchange sleeve, and then cooled by the cooling medium in the cooling chamber. The milling cutter is cooled by heat exchange. Furthermore, the effective heat exchange area is increased by setting multiple heat-conducting fins, thereby improving the cooling efficiency. During the milling operation of this invention, the heat-conducting fins continuously rotate and stir the cooling medium in the cooling chamber to achieve forced convection cooling, which further improves the heat exchange and cooling efficiency.

[0017] 3. When the end mill temperature rises beyond the limit and enters a high-temperature abnormal working condition, the air injection pipe automatically increases the air supply to the moving cylinder, thereby improving the air cooling effect. In addition, the invention simultaneously activates the spray cooling function, which, combined with the flow of air to accelerate the evaporation of droplets, significantly improves the overall heat exchange efficiency. The invention relies on the guiding surface of the umbrella-shaped groove and the blocking and diversion effect of the ball bearings to spray the sprayed material in an umbrella-shaped diffused mist onto the outer surface of the cutter bar, thereby increasing the spray cooling range.

[0018] 4. During the spray cooling process of this invention, the support ring moves back and forth with the movable cylinder, simultaneously driving the ball bearings and the umbrella-shaped spray area to sweep along the tool holder direction, further increasing the coverage area of ​​the atomized medium and enhancing the cooling performance of the tool system under high temperature conditions.

[0019] 5. The present invention forms an auxiliary limiting support for the lower end of the tool holder by means of the cooperation of the support ring and the ball bearing, which shortens the tool overhang length and improves the bending resistance of the tool holder. During the milling operation, it can effectively suppress the cutting chatter of the tool holder and avoid the defects of accelerated tool wear and edge chipping caused by severe vibration. Attached Figure Description

[0020] Figure 1 This is a cross-sectional structural diagram of the present invention.

[0021] Figure 2 This is a schematic diagram of the tool holder mounting structure of the present invention.

[0022] Figure 3 This is a cross-sectional view of the outer cylinder of the present invention.

[0023] Figure 4 This is a schematic diagram of the ball bearing installation structure of the present invention.

[0024] Figure 5 This is a cross-sectional view of the support ring of the present invention.

[0025] Figure 6 This is a schematic diagram of the spray pattern of the present invention.

[0026] Figure 7 For the present invention Figure 5 A magnified structural diagram of part A in the middle.

[0027] In the attached diagram: 1. Tool holder body; 2. Tool holder; 3. Support ring; 4. Nozzle; 5. Outer cylinder; 6. Ball bearing; 7. Electric flow regulating valve; 8. Movable cylinder; 9. Spring; 10. Cooling chamber; 11. Heat exchange jacket; 12. Heat-conducting plate; 13. Electric clamp; 14. Power element; 15. Vent; 16. Damping bearing; 17. First permanent magnet; 18. Second permanent magnet; 19. Mixing chamber; 20. Flow channel; 21. Umbrella groove; 22. Limiting block; 23. One-way valve; 24. Hose; 25. Air injection pipe; 26. Milling cutter head; 27. Solenoid valve. Detailed Implementation

[0028] The following will be for reference. Figures 1 to 7 The various embodiments of the present invention will be described in detail below. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0029] First embodiment: A CNC milling device for precision automotive parts, such as Figure 1 As shown, the device includes a power tool holder and a tool holder 2. The tool holder 2 is detachably connected to the power tool holder. When the power tool holder outputs power, it drives the tool holder 2 and the end mill head 26 at its end to rotate coaxially, completing the milling groove forming process of the workpiece. The tool holder body 1 is equipped with a nozzle 4, which is connected to an external air supply pipe. The air jet port of the nozzle 4 is arranged facing the working area of ​​the cutting edge of the end mill head 26. When the device is running, the nozzle 4 sprays high-pressure airflow into the end mill head 26, and continuously removes the cutting heat generated by the end mill head 26 during operation through convection heat transfer, thereby achieving air cooling of the tool and avoiding problems such as rapid tool wear and melting and sticking chips on the tool head caused by high-temperature operation, thus extending the service life of the tool.

[0030] The power tool holder includes a tool holder body 1, a power element 14 on the tool holder body 1, and a cooling chamber 10 inside. A heat exchange sleeve 11 is rotatably connected through the cooling chamber 10. When the tool bar 2 is inserted into the tool holder body 1, the heat exchange sleeve 11 is fitted onto the tool bar 2 and fits against the outer wall of the tool bar 2. A heat-conducting plate 12 is provided on the heat exchange sleeve 11 in the cooling chamber 10. Both the heat exchange sleeve 11 and the heat-conducting plate 12 are made of a material with high thermal conductivity, such as aluminum alloy. The device is equipped with a water supply pipe seat and a water return pipe seat, which are not shown. The water supply pipe seat and the water return pipe seat are respectively in closed fluid communication with the medium inlet end and the medium outlet end of the cooling chamber 10, forming a circulating water cooling medium passage.

[0031] During the milling operation, the cutting heat generated by the milling cutter head 26 is conducted to the tool holder 2. Then, the heat is transferred to the cooling medium in the cooling chamber 10 by heat exchange sleeve 11 and heat conduction plate 12. The continuous temperature control and cooling of the milling cutter head 26 and tool holder 2 are achieved by liquid cooling heat exchange.

[0032] It should be noted that by setting multiple heat-conducting plates 12, the effective heat exchange area is increased, thereby improving the cooling efficiency. Furthermore, during the milling operation, the heat exchange sleeve 11 will rotate with the tool holder 2, so that the heat-conducting plates 12 rotate and stir the cooling medium in the cooling chamber 10, thereby achieving forced convection cooling and further improving the heat exchange and cooling efficiency.

[0033] The end of the heat exchange sleeve 11 is provided with an electric clamp 13 for fixing the tool bar 2. The output part of the power element 14 is driven and connected to the electric clamp 13. After the electric clamp 13 clamps the tool bar 2, when the power element 14 outputs, it drives the electric clamp 13 to rotate, so that the tool bar 2 and the heat exchange sleeve 11 rotate synchronously.

[0034] Second embodiment: Based on the first embodiment, such as Figures 2-5 As shown, the bottom of the power tool holder is provided with a telescopic cylinder. A support ring 3 for stabilizing the tool bar 2 is provided on the movable part of the telescopic cylinder. The support ring 3 is coaxially sleeved on the tool bar 2. The telescopic cylinder includes an outer cylinder 5, which is installed at the bottom of the tool holder body 1. A movable cylinder 8 is slidably fitted inside the outer cylinder 5. A spring 9 is installed between the inner bottom wall of the movable cylinder 8 and the bottom of the tool holder body 1. The support ring 3 is fixedly installed at the end of the movable cylinder 8 that extends out of the outer cylinder 5. The position of the support ring 3 can be adjusted by the telescopic characteristic of the movable cylinder 8.

[0035] The movable cylinder 8 is equipped with a damping bearing 16, and a first permanent magnet 17 is mounted on the damping bearing 16. The tool holder body 1 is equipped with a second permanent magnet 18 that matches the first permanent magnet 17. When the first permanent magnet 17 is rotated to increase the area corresponding to the second permanent magnet 18, the magnetic repulsion between them increases, pushing the movable cylinder 8 out of the outer cylinder 5, thus moving the support ring 3 away from the tool holder body 1. Conversely, when the first permanent magnet 17 is rotated to decrease the area corresponding to the second permanent magnet 18, the magnetic repulsion between them decreases. Under the action of the spring 9's restoring force, the movable cylinder 8 is pulled into the inner part of the outer cylinder 5, causing the support ring 3 to move closer to the tool holder body 1. This device can adjust the position of the support ring 3 by adjusting the corresponding areas of the first permanent magnet 17 and the second permanent magnet 18. With the setting of the damping bearing 16, the position of the first permanent magnet 17 is automatically fixed after rotation.

[0036] It should be noted that due to the differences in the specifications of milling cutters, the length parameters of the cutter holder 2 vary, and conventional tool holders are difficult to adapt to milling cutters of various sizes and specifications. If the exposed length of the milling cutter holder 2 is too long, the tool is prone to severe chatter during large depth of cut and high speed milling operations, which will aggravate tool wear and even cause problems such as cutting edge breakage.

[0037] In this embodiment, the device is used by rotating the first permanent magnet 17 to change the area corresponding to the magnetic poles of the second permanent magnet 18. As the area corresponding to the two increases, the magnetic repulsion force increases synchronously. Under the driving action of the magnetic repulsion force, the movable cylinder 8 extends out from the inside of the outer cylinder 5, causing the support ring 3 to move away from the tool holder body 1. After the support ring 3 moves close to the lower end of the tool holder 2, the support ring 3 is provided with a ball bearing 6, which forms an auxiliary limiting support for the lower end of the tool holder 2, shortens the tool overhang length, and improves the bending resistance of the tool holder 2. During the milling cutting operation, it can effectively suppress the cutting chatter of the tool holder 2 and avoid the defects of accelerated tool wear and edge chipping caused by severe vibration.

[0038] Third embodiment: It should be noted that existing milling equipment primarily employs two heat dissipation mechanisms for cutting tools: air cooling and coolant spray cooling. While coolant spray cooling offers excellent heat dissipation efficiency, it is unsuitable for machining substrates prone to moisture absorption, delamination, or media penetration, such as PCB boards and powder metallurgy sintered substrates. Air cooling utilizes high-pressure air convection heat transfer to cool the tool, but air's specific heat capacity is far lower than that of coolant, resulting in a low convection heat transfer coefficient. Under conditions of large depth of cut and high-speed milling, tools relying solely on air cooling are still prone to overheating. To address these issues, the following improvements are proposed: Based on the second embodiment, such as Figures 3-5 As shown, a ball spraying mechanism is provided between the support ring 3 and the tool holder 2; the support ring 3 is provided with an air injection mechanism, which has two output parts, one of which is connected to the internal fluid of the telescopic cylinder. The movable cylinder 8 is sleeved on the outside of the tool holder 2, and the support ring 3 has a vent 15. During the milling operation of this device, the tool holder 2 rotates at high speed driven by the power tool holder. Since the balls 6 on the ball spraying mechanism are in close contact with the outer surface of the tool holder 2, the balls 6 roll and coat the cooling medium on the outer wall of the tool holder 2. At the same time, the air injection mechanism continuously injects air into the inner cavity of the movable cylinder 8. After the airflow cools and heats the tool holder 2, it is discharged through the vent 15. The airflow can also promote the evaporation of the cooling medium on the surface of the tool holder 2, which greatly improves the overall cooling efficiency of the tool holder 2 and optimizes the overall temperature control effect of the milling cutter.

[0039] Another output section of the air injection mechanism is equipped with a solenoid valve 27, which is in fluid communication with the ball spray mechanism. When the solenoid valve 27 is opened, the air injection mechanism injects air into the ball spray mechanism, causing the ball spray mechanism to spray water mist onto the outer surface of the cutter bar 2, which further improves the cooling effect on the milling cutter.

[0040] like Figures 4-7 As shown, the ball spraying mechanism includes a mixing chamber 19 formed inside the support ring 3 and several flow channels 20. The input end of the flow channel 20 is in fluid communication with the mixing chamber 19. Several umbrella-shaped grooves 21 are provided on the inner wall of the support ring 3. The output end of the flow channel 20 is in fluid communication with the inside of the umbrella-shaped groove 21. The ball 6 is installed inside the umbrella-shaped groove 21. The support ring 3 is provided with a limiting block 22 for binding the ball 6. The cooling medium in the mixing chamber 19 is input into the inside of the umbrella-shaped groove 21 through the flow channel 20. In this embodiment, the ball 6 abuts against the outer surface of the cutter bar 2. The ball 6 is assembled inside the umbrella-shaped groove 21, and a clearance is reserved between the ball 6 and the groove wall of the umbrella-shaped groove 21 to ensure that the ball 6 can roll freely inside the umbrella-shaped groove 21.

[0041] Several balls 6 are arranged around the circumference of the tool holder 2 and press against the outer wall of the tool holder 2, which plays a role in limiting and assisting the tool holder 2, and can prevent the tool holder 2 from wobble and chatter during high-speed milling. During the milling operation, the tool holder 2 rotates continuously, and the balls 6 are driven to roll by contact friction. During the rolling process, the balls 6 apply the cooling medium to the tool holder 2.

[0042] The mixing chamber 19 is equipped with a one-way valve 23 at its input end, which prevents backflow. The input end of the one-way valve 23 is equipped with a hose 24, which is connected to the internal fluid of the cooling chamber 10. During the operation of this device, the cooling medium in the cooling chamber 10 is input into the mixing chamber 19 through the hose 24, and then input into the umbrella-shaped groove 21 through the flow channel 20.

[0043] The gas injection mechanism includes a gas injection pipe 25 mounted on the support ring 3. The input end of the gas injection pipe 25 is equipped with an electric flow regulating valve 7, which is connected to an external gas supply pipe. The gas injection volume can be adjusted by the electric flow regulating valve 7. The gas injection pipe 25 has two output ends. One output end is in communication with the internal fluid of the movable cylinder 8, and the input end of the solenoid valve 27 is in communication with the other output end. The output end of the solenoid valve 27 is located inside the mixing chamber 19. When the solenoid valve 27 is opened, the high-pressure gas source is introduced into the mixing chamber 19 through the solenoid valve 27. The high-pressure gas flow mixes with the coolant in the mixing chamber 19. Under the action of the internal pressure of the chamber, the gas is sprayed out from the umbrella-shaped groove 21 in the form of water mist to spray and cool the surface of the cutter bar 2. Combined with the airflow in the movable cylinder 8 to accelerate the evaporation of the droplets, the overall heat exchange efficiency is significantly improved.

[0044] It should be noted that, with Figure 6 Based on the guiding surface of the umbrella-shaped groove 21 and the blocking and diversion effect of the ball 6, the sprayed material is sprayed into an umbrella-shaped diffused mist onto the outer surface of the cutter bar 2, which increases the spraying range.

[0045] like Figure 7As shown, the tool holder body 1 is equipped with a temperature sensor for monitoring the temperature of the milling cutter head 26. The temperature sensor is not shown. The electric flow regulating valve 7 and the solenoid valve 27 are both electrically connected to the temperature sensor.

[0046] In the conventional milling operation of the device in this embodiment, the electric flow regulating valve 7 is in the normal opening state, the solenoid valve 27 is in the closed state, and the air source air is sent into the inner cavity of the movable cylinder 8 through the electric flow regulating valve 7 and the air injection pipe 25.

[0047] During the milling process, the tool holder 2 rotates at high speed driven by the power tool holder. As the balls 6 on the ball spray mechanism are in close contact with the outer wall of the tool holder 2, the balls 6 roll and coat the outer wall of the tool holder 2 with the cooling medium. At the same time, the airflow in the inner cavity of the movable cylinder 8 exchanges heat with the tool holder 2 and is discharged through the vent 15. The airflow can also promote the evaporation of the cooling medium on the surface of the tool holder 2, effectively improving the overall cooling efficiency of the tool holder 2, optimizing the overall temperature control effect of the milling cutter, and avoiding problems such as rapid tool wear and melting and sticking chips on the tool tip caused by high-temperature operation.

[0048] When the end mill temperature rises beyond the limit and enters a high-temperature abnormal working condition, the temperature sensing element collects temperature data in real time and feeds back electrical signals to the PLC control system. The control system outputs control commands, which on the one hand drive the electric flow regulating valve 7 to switch to the fully open flow state, and on the other hand control the solenoid valve 27 to perform intermittent opening and closing.

[0049] When the electric flow regulating valve 7 is fully open, the air supply from the air injection pipe 25 to the movable cylinder 8 increases, and the air pressure inside the movable cylinder 8 rises rapidly, pushing the movable cylinder 8 to extend out from the outer cylinder 5. Simultaneously, the support ring 3 slides away from the tool holder body 1. When the solenoid valve 27 is opened, some of the high-pressure airflow inside the air injection pipe 25 is diverted to the mixing chamber 19, and the air flow into the movable cylinder 8 drops instantaneously. As the gas inside the movable cylinder 8 is continuously depressurized through the vent 15, the spring 9 pulls the movable cylinder 8 and the support ring 3 to reset in the opposite direction. That is, during the intermittent opening and closing of the solenoid valve 27, the support ring 3 slides back and forth along the direction of the tool holder 2.

[0050] It should be noted that when the solenoid valve 27 is opened, high-pressure gas is introduced into the mixing chamber 19 through the solenoid valve 27. The airflow mixes with the coolant in the mixing chamber 19. Under the action of the internal pressure of the chamber, it is sprayed out from the umbrella-shaped groove 21 in the form of water mist, which sprays and cools the surface of the tool bar 2. In addition, the airflow in the movable cylinder 8 accelerates the evaporation of the droplets, which significantly improves the overall heat exchange efficiency. Relying on the guiding surface of the umbrella-shaped groove 21 and the blocking and diversion effect of the ball 6, the sprayed material is sprayed onto the outer surface of the tool bar 2 in an umbrella-shaped diffused mist, which increases the spray cooling range.

[0051] It is worth noting that during the repositioning process of the support ring 3 along with the movable cylinder 8, the ball bearing 6 and the umbrella-shaped spray area are simultaneously driven to sweep along the direction of the tool holder 2, further increasing the coverage area of ​​the atomized medium and enhancing the cooling performance of the tool system under high temperature conditions.

[0052] It should be noted that in the description of this invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," which indicate direction or positional relationships, are based on the direction or positional relationships shown in the accompanying drawings. These are used merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0053] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A CNC milling device for precision automotive parts, comprising a power tool holder and a tool holder (2), wherein the tool holder (2) is detachably connected to the power tool holder, characterized in that, The bottom of the power tool holder is provided with a telescopic cylinder, and a support ring (3) for stabilizing the tool bar (2) is provided on the movable part of the telescopic cylinder. The support ring (3) is coaxially sleeved on the tool bar (2), and a ball spraying mechanism is provided between the two. During the rotation of the tool bar (2), the balls (6) on the ball spraying mechanism roll and coat the surface of the tool bar (2) with a cooling medium. The support ring (3) is provided with an air injection mechanism. The air injection mechanism has two outputs. One output is connected to the internal fluid of the telescopic cylinder, and the other output is provided with a solenoid valve (27). The solenoid valve (27) is connected to the ball spray mechanism. When the solenoid valve (27) is opened, the air injection mechanism injects air into the ball spray mechanism, so that the ball spray mechanism sprays water mist onto the outer surface of the cutter bar (2).

2. The CNC milling device for precision automotive parts according to claim 1, characterized in that, The power tool holder includes a tool holder body (1), a power element (14) is provided on the tool holder body (1), and a cooling chamber (10) is provided inside. A heat exchange sleeve (11) is rotatably connected through the cooling chamber (10). The heat exchange sleeve (11) is sleeved on the tool bar (2). A heat-conducting plate (12) is provided on the heat exchange sleeve (11) inside the cooling chamber (10). The end of the heat exchange sleeve (11) is provided with an electric clamp (13) for fixing the knife bar (2), and the output of the power element (14) is driven and connected to the electric clamp (13). When the power element (14) drives the electric clamp (13) to rotate, it causes the tool bar (2) and the heat exchange sleeve (11) to rotate.

3. The CNC milling device for precision automotive parts according to claim 2, characterized in that, The telescopic cylinder includes an outer cylinder (5), which is installed at the bottom of the tool holder body (1). A movable cylinder (8) is slidably fitted inside the outer cylinder (5). A spring (9) is installed between the inner bottom wall of the movable cylinder (8) and the bottom of the tool holder body (1). A support ring (3) is fixedly installed at one end of the movable cylinder (8) that extends out of the outer cylinder (5).

4. The CNC milling device for precision automotive parts according to claim 3, characterized in that, The movable cylinder (8) is sleeved on the outside of the knife bar (2), and the support ring (3) has a vent (15).

5. The CNC milling device for precision automotive parts according to claim 3, characterized in that, The movable cylinder (8) is provided with a damping bearing (16), and the damping bearing (16) is provided with a first permanent magnet (17). The power tool holder is provided with a second permanent magnet (18) that matches the first permanent magnet (17). When the first permanent magnet (17) is rotated to increase the area corresponding to the second permanent magnet (18), the magnetic repulsion between the two increases, pushing the movable cylinder (8) to extend out of the outer cylinder (5).

6. The CNC milling device for precision automotive parts according to claim 3, characterized in that, The ball spraying mechanism includes a mixing chamber (19) opened inside the support ring (3) and several flow channels (20), the input end of the flow channel (20) being in fluid communication with the mixing chamber (19); The inner wall of the support ring (3) is provided with several umbrella-shaped grooves (21). The output end of the flow channel (20) is connected to the internal fluid of the umbrella-shaped groove (21). The ball (6) is installed inside the umbrella-shaped groove (21). The support ring (3) is provided with a limiting block (22) for binding the ball (6).

7. The CNC milling device for precision automotive parts according to claim 6, characterized in that, The mixing chamber (19) is provided with a one-way valve (23) at the input end, and a hose (24) is provided at the input end of the one-way valve (23). The input end of the hose (24) is connected to the internal fluid of the cooling chamber (10).

8. The CNC milling device for precision automotive parts according to claim 6, characterized in that, The gas injection mechanism includes a gas injection pipe (25) installed on the support ring (3). The input end of the gas injection pipe (25) is provided with an electric flow regulating valve (7). The gas injection pipe (25) has two output ends. One output end is connected to the internal fluid of the movable cylinder (8). The input end of the solenoid valve (27) is connected to the other output end. The output end of the solenoid valve (27) is located inside the mixing chamber (19).

9. A CNC milling device for precision automotive parts according to claim 8, characterized in that, The gas injection pipe (25) passes through the mixing chamber (19), and a solenoid valve (27) is provided on the gas injection pipe (25) located inside the mixing chamber (19).

10. A CNC milling device for precision automotive parts according to claim 8, characterized in that, The tool holder body (1) is provided with a nozzle (4), the output direction of the nozzle (4) is set towards the milling cutter head (26), the tool holder body (1) is provided with a temperature sensor for monitoring the temperature of the milling cutter head (26), and the electric flow regulating valve (7) and the solenoid valve (27) are both electrically connected to the temperature sensor.

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