A modified nanodiamond coated micro drill bit and coating growth method

Abstract

This invention discloses a modified nanodiamond-coated micro drill bit and a coating growth method, relating to the field of micro drill bit technology. It includes a drill bit assembly and a transmission and clamping assembly. The drill bit body has an internal cooling chamber, and the transmission and clamping assembly is mounted on the upper outer wall of the drill bit body. This modified nanodiamond-coated micro drill bit and coating growth method can switch between two cooling modes based on the real-time temperature of the working part of the drill bit body. When the temperature is below a preset value, the coolant only passes through the interior of the cooling chamber to remove heat, thereby preventing water stains from adhering to the surface of the drill bit body and affecting its operating accuracy. When the temperature is above the preset value, the valve is closed, increasing the water pressure and raising the casing, causing the drain hole and the water passage hole to coincide. This allows the coolant to be sprayed from the outlet onto the working part of the drill bit body, thereby simultaneously cooling both the inside and outside of the drill bit body, forcing the drill bit body to cool down rapidly.

Description

Technical Field

[0001] This invention relates to the field of micro drill technology, specifically to a modified nanodiamond coated micro drill and a coating growth method. Background Technology

[0002] As electronic products become smaller and more high-performance, there is a need to drill a large number of high-precision microholes in extremely small spaces. Ordinary micro drills face problems such as rapid wear, short lifespan, and difficulty in guaranteeing machining accuracy when processing these materials. However, nanodiamond coatings have excellent properties such as high hardness, low coefficient of friction, good thermal conductivity, and chemical stability, which can significantly improve the cutting performance of micro drills and meet the increasingly stringent processing requirements in these fields.

[0003] Existing modified nanodiamond coated micro drill bits inevitably generate heat during operation. They are usually cooled by external cooling technology, such as spray cooling or air cooling. Spray cooling is prone to forming scale or stains on the drill bit surface, affecting the surface smoothness and thus the accuracy, while air cooling is relatively weak. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a modified nanodiamond coated micro drill bit and a coating growth method, solving the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a modified nanodiamond coated micro drill bit, comprising a drill bit assembly and a transmission clamping assembly. The drill bit assembly includes a drill bit body, a cooling chamber, a bearing, a through cap, a water inlet pipe, a water outlet pipe, a spring telescopic rod, a sleeve, a drain hole, a water passage hole, a tube sleeve, and a water outlet. The drill bit body has a cooling chamber inside, and the top of the drill bit body is rotatably connected to the through cap via a bearing. The surface of the through cap is symmetrically provided with the water inlet pipe and the water outlet pipe. A spring telescopic rod is fixed in the middle of the top surface of the inner wall of the through cap. The bottom of the spring telescopic rod is rotatably connected to the sleeve, and the outer wall of the sleeve has a drain hole. The surface of the drill bit body has a water passage hole, and the outer wall of the drill bit body is fixed with a tube sleeve. The bottom of the tube sleeve has a water outlet. The transmission clamping assembly is provided on the upper outer wall of the drill bit body.

[0006] Furthermore, the outer diameter of the casing is adapted to the inner diameter of the drill bit body, and the casing is elastically connected to the insertion cap via a spring telescopic rod.

[0007] Furthermore, the casing is slidably connected to the drill bit body, and the height of the drain hole on the surface of the drill bit body is lower than the height of the water passage hole on the surface of the drill bit body.

[0008] Furthermore, a circular plate is rotatably connected inside the sleeve, and an inlet pipe and an outlet pipe are symmetrically passed through the surface of the circular plate, and the height of the circular plate is higher than the drain hole.

[0009] Furthermore, the transmission clamping assembly includes a drill chuck and a transmission gear, with the transmission gear fixed to the outer wall of the drill chuck.

[0010] Furthermore, the top of the drill chuck is perforated with an inlet pipe and an outlet pipe, and valves are installed at the ends of both the inlet pipe and the outlet pipe.

[0011] Furthermore, the transmission clamping assembly also includes a drive gear, the side of which is meshed with the drive gear.

[0012] Furthermore, the transmission clamping assembly also includes a drive motor, and the drive motor is connected to the surface of the drive gear.

[0013] A coating growth method, applied to the aforementioned modified nanodiamond coated micro drill bit, the coating growth method comprising the following steps:

[0014] Step 1: The processed drill bit body is cleaned in an ultrasonic cleaner with acetone and ethanol in sequence to remove surface oil and impurities, then rinsed with deionized water, dried and placed in the reaction chamber.

[0015] Step 2: Evacuate the reaction chamber to a high vacuum, reaching a vacuum level of 10. -3 Pa, then hydrogen gas is introduced at a flow rate between 60 and 800 standard cubic centimeters per minute;

[0016] Step 3: Install the tungsten or tantalum wire in a suitable position inside the reaction chamber, keeping it 5-30 mm away from the drill bit body. Heat the wire with a power source to a temperature between 1800-2500℃.

[0017] Step 4: Once the hot filament reaches the set temperature and the atmosphere in the reaction chamber is stable, a carbon source gas, such as methane, is introduced. At the same time, a gas containing modifying elements, such as ammonia, is introduced for nitrogen doping modification according to the modification requirements. The carbon source gas and the modifying gas decompose under the catalytic action of the hot filament, and the resulting active carbon atoms and modifying element atoms are deposited on the surface of the drill bit body and gradually grow to form a modified nanodiamond coating.

[0018] Furthermore, in step four, during the reaction of the carbon source gas and the modified gas, the pressure in the reaction chamber is generally controlled between 1 and 10 kPa.

[0019] This invention provides a modified nanodiamond coated micro drill bit and a coating growth method, which has the following beneficial effects:

[0020] This modified nanodiamond coated micro drill bit and coating growth method can switch between two cooling modes based on the real-time temperature of the working part of the drill bit body. When the temperature is lower than the preset value, the coolant only passes through the inside of the cooling chamber to remove heat, thereby avoiding water stains adhering to the surface of the drill bit body and affecting its working accuracy. When the temperature is higher than the preset value, the water pressure inside the cooling chamber is increased by closing the valve at the end of the water outlet pipe, thereby raising the sleeve and making the drain hole coincide with the water passage hole. This allows the coolant to be sprayed from the water outlet at the bottom of the sleeve to the working part of the drill bit body, thereby cooling both the inside and outside of the drill bit body at the same time, forcing the drill bit body to cool down quickly and avoiding heat accumulation in the drill bit body that affects its lifespan and accuracy. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the meshing connection structure between the transmission gear and the drive gear of a modified nanodiamond coated micro drill bit according to the present invention.

[0022] Figure 2 This is a schematic diagram of the cap structure of a modified nanodiamond coated micro drill bit according to the present invention;

[0023] Figure 3 This is a schematic diagram of the sleeve structure of a modified nanodiamond coated micro drill bit according to the present invention;

[0024] Figure 4 This is a schematic diagram of the casing structure of a modified nanodiamond coated micro drill bit according to the present invention;

[0025] Figure 5 This is a schematic cross-sectional view of the drill bit body of a modified nanodiamond coated micro drill bit according to the present invention.

[0026] In the diagram: 1. Drill bit assembly; 101. Drill bit body; 102. Cooling chamber; 103. Bearing; 104. Through cap; 105. Water inlet pipe; 106. Water outlet pipe; 107. Spring telescopic rod; 108. Sleeve; 109. Drain hole; 110. Water passage hole; 111. Pipe sleeve; 112. Water outlet; 2. Transmission clamping assembly; 201. Drill chuck; 202. Transmission gear; 203. Drive gear; 204. Drive motor. Detailed Implementation

[0027] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0028] like Figures 1-5As shown, the present invention provides a technical solution: a modified nanodiamond coated micro drill bit, comprising a drill bit assembly 1 and a transmission clamping assembly 2. The drill bit assembly 1 includes a drill bit body 101, a cooling chamber 102, a bearing 103, a through cap 104, a water inlet pipe 105, a water outlet pipe 106, a spring telescopic rod 107, a sleeve 108, a drain hole 109, a water passage hole 110, a tube sleeve 111, and a water outlet 112. The cooling chamber 102 is provided inside the drill bit body 101, and the top of the drill bit body 101 rotates via the bearing 103. A drill bit body 101 is connected to a drill bit cap 104. A water inlet pipe 105 and a water outlet pipe 106 are symmetrically inserted through the surface of the drill bit cap 104. A spring telescopic rod 107 is fixed to the center of the top surface of the inner wall of the drill bit cap 104. A sleeve 108 is rotatably connected to the bottom of the spring telescopic rod 107. A drain hole 109 is provided on the outer wall of the sleeve 108. A water passage hole 110 is provided on the surface of the drill bit body 101. A pipe sleeve 111 is fixed to the outer wall of the drill bit body 101. A water outlet 112 is provided at the bottom of the pipe sleeve 111. The upper outer wall of the drill bit body 101 is provided with… The transmission clamping assembly 2 has a sleeve 108 whose outer diameter matches the inner diameter of the drill bit body 101. The sleeve 108 is elastically connected to the through cap 104 via a spring telescopic rod 107. The sleeve 108 is slidably connected to the drill bit body 101. The height of the drain hole 109 on the surface of the drill bit body 101 is lower than the height of the water passage hole 110 on the surface of the drill bit body 101. A circular plate is rotatably connected inside the sleeve 108, and a water inlet pipe 105 and a water outlet pipe 106 are symmetrically passed through the surface of the circular plate. The height of the circular plate is higher than the drain hole 109. 09. The transmission clamping assembly 2 includes a drill chuck 201 and a transmission gear 202. The transmission gear 202 is fixed on the outer wall of the drill chuck 201. The top of the drill chuck 201 has a water inlet pipe 105 and a water outlet pipe 106 passing through it. Valves are provided at the ends of the water inlet pipe 105 and the water outlet pipe 106. The transmission clamping assembly 2 also includes a drive gear 203. The drive gear 203 is meshed with the side of the transmission gear 202. The transmission clamping assembly 2 also includes a drive motor 204. The drive motor 204 is connected to the surface of the drive gear 203.

[0029] The specific operation is as follows: First, the working process of the drill body 101 is as follows: the drive motor 204 drives the drive gear 203 to rotate, which causes the transmission gear 202 to drive the drill chuck 201 to rotate, thereby causing the drill body 101 held inside the drill chuck 201 to rotate at high speed to perform drilling or turning operations. The drill chuck 201 holds the upper area of ​​the outer wall of the drill body 101, and the through cap 104 is rotatably connected to the drill body 101 through the bearing 103. The rotation of the drill body 101 does not affect the through cap 104.

[0030] A temperature sensor is used to monitor the temperature of the drill bit body 101 in real time on the outside of the drill bit body 101. When the temperature is below the preset value, a pump body is connected to the end of the water inlet pipe 105. The pump body injects coolant into the water inlet pipe 105. The coolant enters the cooling chamber 102 and is located below the disc of the sleeve 108. The coolant absorbs heat inside the drill bit body 101. After absorbing heat, the coolant is discharged outward along the water outlet pipe 106. Thus, cooling water flows inside the drill bit body 101 to remove heat, and no water stains are generated. This avoids the formation of stains or scale on the outer surface of the drill bit body 101 after water stains dry, which would affect its surface smoothness and prevent the working accuracy of the drill bit body 101 from being affected.

[0031] When the temperature of the working part of the drill bit body 101 is detected to be higher than the preset value, the valve at the end of the water outlet pipe 106 is closed. At this time, the coolant enters the cooling chamber 102 and is located below the disc of the sleeve 108. As the water pressure increases, the disc is raised, causing the sleeve 108 to slide upward along the inside of the drill bit body 101. At this time, the spring telescopic rod 107 is compressed until the drain hole 109 on the outer wall of the sleeve 108 is highly aligned with the water passage hole 110 on the surface of the drill bit body 101. At this time, the coolant inside the cooling chamber 102 flows through the drain hole 109 and the water passage hole 110 and then flows along the inside of the sleeve 111. Finally, the coolant is sprayed from the outlet 112 at the bottom of the sleeve 111 to the working part of the drill bit body 101. By changing the flow direction of the coolant, it passes through the inside and outside of the working part of the drill bit body 101 in sequence, thereby cooling the drill bit body 101 from both the inside and outside simultaneously to improve the cooling effect.

[0032] Based on the above description, the present invention can switch between two cooling modes based on the real-time temperature of the working part of the drill bit body 101. When the temperature is lower than the preset value, the coolant only passes through the inside of the cooling chamber 102 to remove heat, thereby preventing water stains from adhering to the surface of the drill bit body 101 and affecting its working accuracy. When the temperature is higher than the preset value, the water pressure inside the cooling chamber 102 is increased by closing the valve at the end of the water outlet pipe 106, thereby raising the sleeve 108, so that the drain hole 109 coincides with the water passage hole 110, thereby causing the coolant to spray from the water outlet 112 at the bottom of the sleeve 111 to the working part of the drill bit body 101. This simultaneously cools the inside and outside of the drill bit body 101, forcing the drill bit body 101 to cool down quickly and preventing heat accumulation in the drill bit body 101 from affecting its lifespan and accuracy.

[0033] A coating growth method, applied to the aforementioned modified nanodiamond coated micro drill bit, includes the following steps:

[0034] Step 1: The processed drill bit body 101 is cleaned in an ultrasonic cleaner with acetone and ethanol in sequence to remove oil and impurities from the surface, then rinsed with deionized water, dried and placed in the reaction chamber.

[0035] Step 2: Evacuate the reaction chamber to a high vacuum, reaching a vacuum level of 10. -3 Pa, then hydrogen gas is introduced at a flow rate between 60 and 800 standard cubic centimeters per minute;

[0036] Step 3: Install the tungsten wire or tantalum wire in a suitable position inside the reaction chamber, keeping it 5-30 mm away from the drill bit body 101. Heat the wire with a power source to a temperature between 1800-2500℃.

[0037] Step 4: When the hot wire reaches the set temperature and the atmosphere in the reaction chamber is stable, a carbon source gas such as methane is introduced. At the same time, a gas containing modifying elements, such as ammonia, is introduced according to the modification requirements for nitrogen doping modification. The carbon source gas and the modifying gas decompose under the catalytic action of the hot wire. The generated active carbon atoms and modifying element atoms are deposited on the surface of the drill bit body 101 and gradually grow to form a modified nanodiamond coating.

[0038] In step four, during the reaction of the carbon source gas and the modified gas, the pressure in the reaction chamber is generally controlled between 1 and 10 kPa.

[0039] In summary, when using the modified nanodiamond coated micro drill bit and coating growth method, the first working process of the drill bit body 101 is as follows: the drive motor 204 drives the drive gear 203 to rotate, which causes the transmission gear 202 to drive the drill chuck 201 to rotate, thereby causing the drill bit body 101 held inside the drill chuck 201 to rotate at high speed for drilling or turning operations.

[0040] A temperature sensor is used to monitor the temperature of the drill bit body 101 in real time outside the drill bit body 101. When the temperature is below the preset value, a pump body is connected to the end of the water inlet pipe 105. The pump body injects coolant into the water inlet pipe 105. The coolant enters the cooling chamber 102 and is located below the disc of the casing 108. The coolant absorbs heat inside the drill bit body 101. After absorbing heat, the coolant is discharged outward along the water outlet pipe 106.

[0041] When the temperature of the working part of the drill bit body 101 is detected to be higher than the preset value, the valve at the end of the water outlet pipe 106 is closed. At this time, the coolant enters the cooling chamber 102 and is located below the disc of the sleeve 108. As the water pressure increases, the disc is raised, causing the sleeve 108 to slide upward along the inside of the drill bit body 101. At this time, the spring telescopic rod 107 is compressed until the drain hole 109 on the outer wall of the sleeve 108 is highly aligned with the water passage hole 110 on the surface of the drill bit body 101. At this time, the coolant inside the cooling chamber 102 passes through the drain hole 109 and the water passage hole 110 and flows along the inside of the sleeve 111. Finally, the coolant is sprayed from the outlet 112 at the bottom of the sleeve 111 to the working part of the drill bit body 101. This changes the flow direction of the coolant, allowing it to pass through the inside and outside of the working part of the drill bit body 101 in sequence, thereby cooling the drill bit body 101 from both the inside and outside.

[0042] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A modified nanodiamond-coated micro drill bit, comprising a drill bit assembly (1) and a transmission clamping assembly (2), characterized in that: The drill bit assembly (1) includes a drill bit body (101), a cooling chamber (102), a bearing (103), a drill bit cap (104), a water inlet pipe (105), a water outlet pipe (106), a spring telescopic rod (107), a sleeve (108), a drain hole (109), a water passage hole (110), a pipe sleeve (111), and a water outlet (112). The drill bit body (101) has a cooling chamber (102) inside, and the top of the drill bit body (101) is rotatably connected to the drill bit cap (104) through the bearing (103). The surface of the drill bit cap (104) is symmetrically perforated with water inlets and outlets. A water pipe (105) and a water outlet pipe (106) are provided, and a spring telescopic rod (107) is fixed in the middle of the top surface of the inner wall of the cap (104). The bottom of the spring telescopic rod (107) is rotatably connected to a sleeve (108), and a drain hole (109) is provided on the outer wall of the sleeve (108). A water passage hole (110) is provided on the surface of the drill bit body (101), and a pipe sleeve (111) is fixed on the outer wall of the drill bit body (101). A water outlet (112) is provided at the bottom of the pipe sleeve (111). A transmission clamping assembly (2) is provided on the upper outer wall of the drill bit body (101).

2. The modified nanodiamond coated micro drill bit according to claim 1, characterized in that: The outer diameter of the casing (108) is adapted to the inner diameter of the drill bit body (101), and the casing (108) is elastically connected to the through cap (104) through a spring telescopic rod (107).

3. The modified nanodiamond coated micro drill bit according to claim 1, characterized in that: The casing (108) is slidably connected to the drill bit body (101), and the height of the drain hole (109) on the surface of the drill bit body (101) is lower than the height of the water passage hole (110) on the surface of the drill bit body (101).

4. The modified nanodiamond coated micro drill bit according to claim 1, characterized in that: The sleeve (108) has a circular plate rotatably connected inside, and the surface of the circular plate is symmetrically penetrated by the water inlet pipe (105) and the water outlet pipe (106), and the height of the circular plate is higher than the drain hole (109).

5. The modified nanodiamond coated micro drill bit according to claim 1, characterized in that: The transmission clamping assembly (2) includes a drill chuck (201) and a transmission gear (202), with the transmission gear (202) fixed to the outer wall of the drill chuck (201).

6. A modified nanodiamond-coated micro drill bit according to claim 5, characterized in that: The top of the drill chuck (201) is connected to an inlet pipe (105) and an outlet pipe (106), and valves are provided at the ends of both the inlet pipe (105) and the outlet pipe (106).

7. A modified nanodiamond-coated micro drill bit according to claim 5, characterized in that: The transmission clamping assembly (2) further includes a drive gear (203), and the drive gear (203) is meshed with the side of the transmission gear (202).

8. A modified nanodiamond-coated micro drill bit according to claim 7, characterized in that: The transmission clamping assembly (2) also includes a drive motor (204), and the drive gear (203) has the drive motor (204) connected to its surface.

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