Hole machining cutter for engineering ceramic material

Abstract

A hole machining cutter for engineering ceramic materials comprises a micro-grinding head located at the front end, a drill bit located in the middle and a cutter handle located at the rear end, the micro-grinding head is in a cylinder shape, diamond abrasive particles are fully distributed on the surface of the micro-grinding head, and two spiral grooves are formed in the cylindrical surface of the micro-grinding head; the drill is in a common drill shape, and the top of the drill is fixedly connected with the end of the micro-grinding head. And the cutter handle is fixedly connected with the drill bit. The shape of the drill bit is improved on the basis of a common drill bit, the micro-grinding head is used for replacing an original drill tip part, and during drilling, a small hole is ground through the micro-grinding head at the front end, so that the subsequent drill bit can enter a designated area conveniently, and the blade length of the drill bit participating in cutting is effectively reduced; a drill point and a nearby blade with low cutting speed are prevented from participating in machining during drilling of an original drill bit, the cutting force in machining is reduced, the machining quality is improved, and the service life of a cutter is prolonged.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical manufacturing and processing technology, and in particular relates to a hole-making tool for hard and brittle materials such as engineering ceramics. Background Technology

[0002] Advanced engineering ceramic materials possess excellent physical and chemical properties, exhibiting superior corrosion resistance compared to general metallic materials under various harsh chemical conditions. They are widely used in defense, aerospace, and modern high-tech industries. However, the machining of ceramic materials is easily limited by process conditions, making it difficult to accurately pre-drill holes and grooves for positioning and assembly. Therefore, drilling is frequently required in the production of engineering ceramic products. In drilling, to extend the service life of the cutting parts, relatively expensive cemented carbide or superhard materials (such as PCD and PCBN) tool materials are typically used. These materials are characterized by high hardness and good wear resistance, but are extremely difficult to machine, resulting in high costs for both drilling tool materials and machining. On the one hand, in drilling, the cutting edge of the drill bit is V-shaped. This shape of the cutting edge is relatively long, resulting in a large contact area with the workpiece in the hole and a large cutting force. Even when this type of material is used, there are still problems such as poor machining quality and short tool life, which increases production costs and reduces production efficiency. On the other hand, the central area (the very top) of the drill bit tip is called the axis of the drill bit. The cutting speed is zero at the axis position, which cannot achieve effective cutting. This can easily lead to material extrusion deformation and heat accumulation, thereby affecting machining quality and tool life.

[0003] Currently, the cutting tools used for machining holes in hard and brittle materials such as engineering ceramics are mostly single-function drilling and grinding tools. Among them, the cutting force on the tool is large during drilling and grinding, resulting in significant tool damage, poor hole quality, low precision, and inability to guarantee machining quality, making it difficult to meet the demand for improved hole machining quality in mechanical parts. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to address the shortcomings of existing cutting tool technology by proposing a hole-making tool for hard and brittle materials such as engineering ceramics. Based on a conventional drill bit, its shape is improved by replacing the original drill tip with a micro-grinding head. During drilling, a small hole is ground by the micro-grinding head at the front end, which facilitates the subsequent drill bit to enter the designated area. This effectively reduces the cutting edge length of the drill bit involved in cutting, eliminates the participation of the drill tip and the low-speed cutting edge near it in the original drill bit's drilling process, reduces the cutting force during processing, and improves the processing quality and tool life.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A hole-making tool for engineering ceramic materials includes a micro-grinding head at the front end, a drill bit in the middle, and a tool holder at the rear end. The micro-grinding head is cylindrical in shape, with diamond abrasive grains covering its surface and two helical grooves on its cylindrical surface. The drill bit is in the shape of a conventional drill bit, with its top fixedly connected to the end of the micro-grinding head. The tool holder is fixedly connected to the drill bit.

[0007] Furthermore, through holes are provided on the tool axis to improve the cooling and lubrication effect of the coolant.

[0008] Furthermore, the cylindrical side of the micro-grinding head has two spiral grooves extending from the spiral groove of the drill bit, which enhances the smoothness of chip removal during micro-grinding and can also be used to accommodate the chips generated during grinding, preventing blockage and secondary damage to the abrasive layer. The side surface and bottom have electroplated or brazed diamond abrasive grains with a diamond grit size of 150#-180#, which are used for pre-drilling roughing and machining guidance.

[0009] Furthermore, the drill bit is in the shape of a regular twist drill, but without a drill tip or chisel edge, and the two main cutting edges intersect with the side of the micro-grinding head.

[0010] Furthermore, the tool substrate is made of cemented carbide, and the drill bit cutting edge is made of PCD inserts, which are pressed onto the cemented carbide substrate by brazing.

[0011] Furthermore, the diameter of the micro-grinding head is 0.3 to 0.5 times the diameter of the drill bit, and the length of the micro-grinding head is 0.8 to 1.2 times its own diameter.

[0012] Compared with the prior art, this utility model has the following advantages and effects: Unlike previous single hole-making tools, this utility model fully utilizes the advantages of combining drill bits and micro-grinding heads to complete the machining of holes on the surface of hard and brittle materials such as engineering ceramics. Furthermore, by adopting the tool structure of this utility model, the cutting edge length of the drill bit participating in the cutting can be effectively reduced when drilling engineering ceramics. At the same time, the cutting edge with low cutting speed at the drill tip and its vicinity can be replaced by a micro-grinding head, which reduces the cutting force during machining and improves machining quality and tool life. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a hole-machining tool used for hard and brittle materials such as engineering ceramics.

[0014] Figure 2 This is a bottom view of the micro-grinding head.

[0015] Figure 3 Schematic diagram of drill bit processing. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] like Figure 1 , Figure 2 As shown, a hole-making tool for engineering ceramic materials includes a micro-grinding head 3 at the front end, a drill bit 2 in the middle, and a tool holder 1 at the rear end. The micro-grinding head 3 is cylindrical in shape, with diamond abrasive grains covering its surface and two spiral grooves on its cylindrical surface. The drill bit 2 is a regular drill bit, with its top fixedly connected to the end of the micro-grinding head 3. The tool holder 1 is fixedly connected to the drill bit 2.

[0018] like Figure 1 , Figure 2 As shown, this utility model has a through hole 4 on the tool axis to improve the cooling and lubrication effect of the coolant.

[0019] like Figure 1 As shown, the cylindrical side of the micro-grinding head 3 of this utility model has two spiral grooves extending from the spiral groove of the drill bit, which enhances the smoothness of chip removal during micro-grinding and can also be used to accommodate the chips generated during grinding, preventing clogging and secondary damage to the abrasive layer. The side surface and bottom of the micro-grinding head 3 have electroplated or brazed diamond abrasive grains with a diamond grit size of 150#-180#, which are used for pre-drilling roughing and machining guidance.

[0020] like Figure 1 As shown, the drill bit 2 of this utility model is in the shape of a common twist drill, but without a drill tip or transverse cutting edge, and the two main cutting edges intersect with the side of the micro-grinding head.

[0021] The tool substrate of this utility model is cemented carbide, and the cutting edge of the drill bit is a PCD insert 21, which is pressed onto the cemented carbide substrate by brazing.

[0022] The diameter of the micro-grinding head 3 of this utility model is 0.3 to 0.5 times the diameter of the drill bit 2, and the length of the micro-grinding head 3 is 0.8 to 1.2 times its own diameter.

[0023] like Figure 3 As shown, when drilling engineering ceramics, the micro-grinding head 3 at the front end participates in the processing first, removing part of the material in the hole. After the processing depth reaches the length of the micro-grinding head 3, the drill bit 2 in the middle participates in the processing, and the PCD insert 21 at the cutting edge of the drill bit removes the remaining material in the hole. This method can avoid the problem that the drill tip axis position cannot generate cutting action due to the lack of cutting speed, and at the same time reduce the amount of material removed from the cutting edge of the drill bit, thereby reducing the cutting force on the tool and extending the tool life.

[0024] This invention fully considers the requirements for high quality and low tool damage in hole machining. Utilizing the characteristics of drilling and grinding processes and the advantages of traditional twist drills, it proposes a hole machining tool for hard and brittle materials such as engineering ceramics. The tool structure of this invention effectively reduces the cutting edge length of the drill bit when drilling engineering ceramics. Furthermore, compared to ordinary drill bits, the lower cutting speed portion at and near the drill tip is replaced by a micro-grinding head, which reduces cutting forces during machining, improves machining quality, and extends tool life.

[0025] The embodiments of this utility model are not limited to the above-described embodiments. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A tool for machining holes in engineering ceramic materials, characterized in that: It includes a micro-grinding head (3) at the front end, a drill bit (2) in the middle, and a tool holder (1) at the rear end. The micro-grinding head (3) is cylindrical in shape and covered with diamond abrasive grains. Two spiral grooves are opened on the cylindrical surface. The drill bit (2) is in the shape of a regular drill bit and is fixedly connected to the end of the micro-grinding head (3) at its top. The tool holder (1) is fixedly connected to the drill bit (2).

2. The hole-making tool for engineering ceramic materials according to claim 1, characterized in that: A through hole (4) is provided on the tool axis to improve the cooling and lubrication effect of the coolant.

3. A hole-machining tool for engineering ceramic materials according to claim 1, characterized in that: The micro-grinding head (3) has two spiral grooves extending from the spiral groove of the drill bit on its cylindrical side. The side surface and bottom of the grinding head have electroplated or brazed diamond abrasive grains with a diamond grain size of 150#-180#, which are used for pre-drilling roughing and machining guidance.

4. A hole-machining tool for engineering ceramic materials according to claim 1, characterized in that: The drill bit (2) is in the shape of a regular twist drill, but without a drill tip or transverse cutting edge. The two main cutting edges intersect with the side of the micro-grinding head.

5. A hole-machining tool for engineering ceramic materials according to claim 1, characterized in that: The tool body is made of cemented carbide, and the cutting edge of the drill bit is made of PCD inserts, which are pressed onto the cemented carbide body by brazing.

6. A hole-machining tool for engineering ceramic materials according to claim 1, characterized in that: The diameter of the micro-grinding head (3) is 0.3 to 0.5 times the diameter of the drill bit (2), and the length of the micro-grinding head (3) is 0.8 to 1.2 times its own diameter.

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