The tips of improve PCD tool grinding machine technology
First, the PCD tool grinding machine equipment selection
In order to improve the sharpening efficiency of PCD tools, sharpening equipment needs to have certain conditions, mainly in the following aspects:
1. Sufficient rigidity and stability: Due to the extremely high hardness of the material to be ground, the PCD tool material cannot remove without a certain pressure between the grinding wheel and the workpiece being ground. Therefore, the grinding wheel shaft and other mechanisms must have sufficient rigidity. In addition, the spindle power should large enough, not less than 1 kW, 2 kW is recommended.
2. Unique grinding wheel swinging mechanism: Unlike the general PCD tool grinding machine, the special tool grinding machine adopts the grinding wheel frame for the lateral swing to prevent the groove on the surface of the grinding wheel due to the low wear ratio of the grinding wheel. The grinding machine should adopt precision. Bearings, precision guides, and precision belt drive systems to avoid edge quality due to small vibrations caused by the wheel's oscillating commutation.
3. The grinding force can adjust in size: according to the different tools to process and the grinding wheel used. The grinding pressure should adjustable to achieve constant pressure. The purpose of adjusting the grinding force is to compensate for the change of the grinding force in the contact area between the grinding wheel and the workpiece. By adjusting the pressure during rough grinding and fine grinding, the grinding force can optimize for the various grinding wheels used.
4. High-precision rotary table system and an optical projection device. The advanced tool grinding machine generally has an optical projection device and high-precision rotary table, so that after the card is installed. Not only the cutting edge can ground, but also the two can accurately ground. The tool arc between the blades, and the arc and edge quality can directly observe on the machine through the projection device.
5. The coolant can fully supply: the cooling system must have a flow rate of at least 20 L/min, and an aqueous solution with a rust inhibitor is usually used as the coolant.
Second, the selection and finishing of the grinding wheel
1. Granular choice
The smaller the particle size of the grinding wheel, the flatter the surface is polished. And the lower the surface roughness obtained by grinding. However, under the premise of satisfying the processing requirements of the cutting edge of the tool, the coarse-grained grinding wheel should select as much as possible. So that the processing quality can ensure and the processing efficiency can improve. For the grinding process of PCD tool grinding machine, it is difficult to achieve satisfactory results by selecting a grinding wheel with particle size. Generally, two or three different grinding wheels are used for coarse and fine grinding.
2. The choice of binder
At present, the commonly used diamond grinding wheel has three kinds of resin bonding agent, metal bonding agent and ceramic bonding agent diamond grinding wheel. And its characteristics are different and can flexibly apply according to processing methods and processing conditions.
(1) Metal bond grinding wheel characteristics: The more common one is the bronze bond. The bronze bond diamond grinding wheel is characterized by good formability, high strength, and certain toughness, but poor self-tanning.
(2) Resin bond grinding wheel characteristics: high strength, good elasticity, stable combination. But the resin material is polymer material, no fixed melting point, poor heat resistance when the grinding temperature reaches 200-300 ° C. Its binding ability Greatly reduced.
(3) Characteristics of the ceramic bond grinding wheel: The ceramic bond grinding wheel is characterized by high hardness. The good self-tanning property, stable chemical property, water resistance, heat resistance, acid resistance, and low cost. However, the ceramic-integrated grinding wheel is generally powder-formed, and the uniformity of the molded body is difficult to ensure and is relatively brittle so that the abrasive grains and the binder tend to collectively fall off during the grinding process.
3. Dressing of the grinding wheel
Grinding wheel dressing is essential in grinding. By dressing, the grinding wheel can keep in a good working condition, ensuring machining efficiency and processing quality. The smoother the dressing of the grinding wheel, the smaller the surface roughness value of the machined surface. To obtain a very low roughness value to grind the surface, the grinding wheel must finely finish. In addition, during the tool grinding process, the working surface of the grinding wheel will block by the grinding debris. At this time, if you continue to use it, the exposed portion of the diamond becomes smaller. The grinding ability is reduced, and the grinding pressure is increased, which will increase the vibration of the machine tool and affect the processing quality. At the same time, the frictional force increases and the heat generation increases. It is possible to burn the PCD blade. In order to avoid the above situation and ensure the processing efficiency and processing quality. It is necessary to trim the grinding wheel in the grinding process, and the dressing tool generally adopts a silicon carbide sand bar.
Third, the PCD tool clamping and adjustment
First, the center of the rotary table of the cross table and the center of the optical projector should adjust. Then, according to the drawings, the PCD tool grinding machine can adjust to the optical projector's reference line through the cross table. This position is sharpening. position. In order to ensure the accuracy of the PCD tool, all the grinding dimensions should complete in one setup. If grinding the PCD tool, all the wear must remove.
Fourth, the vibration parameters of the diamond grinding wheel
Since the diamond grinding wheel is relatively expensive, in order to make full use of the efficiency of the grinding wheel and prevent the occurrence of groove marks. According to the size of the PCD tool grinding machine, attention should pay to the amplitude of the swing, and the grinding wheel and the frequency can ensure by adjusting the swing and frequency of the grinding wheel of the grinding machine tool wheel. The degree of coincidence of the tool is greater than or equal to 1.
Five, the minimum sharpening margin of PCD tools
Usually, the cost of sharpening is very high during the tool making process, and minimizing the amount of removal is the goal pursued. The minimum machining allowance depends on the cutting mode and the depth of damage to the PCD during the heating process. It consists of three parts: one is the depth of damage to the surface layer by the cutting method. The other is the depth of damage to the internal tissue by the cutting method. The third is the influence of the heating method.
Demina is a professional PCD tool grinding machine manufacturer. We produce various types of PCD tool grinder. The equipment performance is good, the quality is reliable, and the factory price for sale. Welcome everyone to come to buy, or come to our factory to visit.
