Process method for trimming metal-based CBN conductive grinding wheel through discharge electrolysis

Abstract

The invention discloses a process method for trimming a metal-based CBN conductive grinding wheel through discharge electrolysis, the metal-based CBN conductive grinding wheel is trimmed through a discharge electrolysis machining process, a tool for trimming the conductive grinding wheel is a block-shaped red copper sample piece, and the conductive grinding wheel keeps rotating at a high speed; a numerical control grinding machine is used for controlling a machining gap between the conductive grinding wheel and the red copper sample piece to achieve the discharge electrolysis effect, and the X axis and the Z axis are moved to trim different areas of the end face and the radial circumferential face of the conductive grinding wheel till the size and the abrasive particle protruding height of the trimmed conductive grinding wheel meet the requirements. The finished conductive grinding wheel can achieve simultaneous machining of the end face and the radial circumferential face, and can machine structures such as steps. According to the process, the CBN abrasive particles and the base body can be rapidly removed through the discharge effect, the size precision and the surface quality of the conductive grinding wheel are improved, the base body can be removed through the electrolysis effect, the CBN abrasive particles have a certain protruding height, the finishing efficiency and precision are effectively improved through the process, and the cost is reduced.

Description

Technical Field

[0001] The invention relates to the field of special processing, and in particular to a process for dressing a metal-based CBN conductive grinding wheel by discharge electrolysis. Background Art

[0002] The metal-based CBN conductive grinding wheel is made of a metal matrix composed of copper, nickel and zinc elements, CBN abrasives and adhesives through a powder metallurgy process. Its abrasive layer is thicker than that of a general electroplated conductive grinding wheel, so it can be reused after multiple dressings. CBN abrasives have the characteristics of high hardness and high compressive strength. High hardness means stronger and sharper cutting ability, and CBN has high wear resistance, which means it is more difficult to wear than ordinary abrasives. The ability to maintain the shape of abrasives is one of the main characteristics of CBN as a high-performance abrasive. Not only that, CBN has high compressive strength, and it can keep the particles intact and not easily broken when used under harsh conditions.

[0003] The current electrospark dressing process is based on the discharge effect between diamond and metal-based CBN conductive grinding wheel to dress the conductive grinding wheel surface. During the dressing process, the electrospark action will remove the metal matrix and CBN abrasives at the same time. Although the surface of the conductive grinding wheel after dressing is very flat, the CBN abrasives without protrusion height cannot achieve grinding. The conductive grinding wheel can only have a certain protrusion height through oilstone grinding. Complex procedures, low efficiency and high costs are important factors restricting the development of electrospark dressing of metal-based CBN conductive grinding wheels. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a process method for dressing a metal-based CBN conductive grinding wheel by discharge electrolysis in view of the defects involved in the background technology, which can ensure the dressing efficiency and reduce the cost.

[0005] The present invention adopts the following technical solutions to solve the above technical problems: A process for dressing a metal-based CBN conductive grinding wheel by discharge electrolysis comprises the following steps: Step 1), the metal-based CBN conductive grinding wheel and the rotating spindle of the CNC grinder are coaxially fixedly connected, and the CNC grinder realizes its reciprocating movement in the X, Y, and Z axes and the rotational movement in the Z axis; the copper sample is clamped and fixed on the machine tool workbench by a mechanical bench clamp, and the electrolyte in the processing area is provided by a flexible nozzle capable of adjusting the angle; the rotating spindle of the CNC grinder is perpendicular to the machine tool workbench; the copper sample is a rectangular plate, and its length direction is the X-axis direction, the width direction is parallel to the axis of the rotating spindle of the CNC grinder and is the Z-axis direction, and the direction perpendicular to the copper sample is the Y direction; the width of the copper sample is greater than or equal to the thickness of the metal-based CBN conductive grinding wheel; Step 2), connect the metal-based CBN conductive grinding wheel to the positive electrode of the power supply, and connect the copper sample to the negative electrode of the power supply, to ensure that the flexible nozzle supplies electrolyte to the processing area at a constant electrolyte pressure; Step 3), adjusting the position of the metal-based CBN conductive grinding wheel by a numerically controlled grinder, so that the center of the copper sample and the metal-based CBN conductive grinding wheel are coplanar, and the lower end surface of the abrasive layer of the metal-based CBN conductive grinding wheel is directly above the copper sample, and a discharge gap is maintained between the two, and the metal-based CBN conductive grinding wheel is controlled by the numerically controlled grinder to rotate at a high speed and to perform a cyclic reciprocating motion along the X-axis direction, and discharge electrolysis is realized in the electrolyte provided by the flexible nozzle, and the lower end surface of the abrasive layer of the metal-based CBN conductive grinding wheel is trimmed until the processing gap exceeds the discharge gap; Step 4), adjusting the position of the metal-based CBN conductive grinding wheel by a CNC grinder so that the lower end surface of the abrasive layer of the metal-based CBN conductive grinding wheel and the copper sample maintain a discharge gap; Step 5), repeating steps 3) to 4), until the lower end surface of the abrasive layer of the metal-based CBN conductive grinding wheel is finished; Step 6), adjusting the position of the metal-based CBN conductive grinding wheel by a numerically controlled grinder, so that the center of the copper sample and the metal-based CBN conductive grinding wheel are coplanar, the radial circumferential surface of the metal-based CBN conductive grinding wheel corresponds to the width of the copper sample and a discharge gap is maintained between the two, the metal-based CBN conductive grinding wheel is controlled by the numerically controlled grinder to rotate at a high speed and to perform a cyclic reciprocating motion along the Z-axis direction, discharge electrolysis is achieved in the electrolyte provided by the flexible nozzle, and the radial circumferential surface of the abrasive layer of the metal-based CBN conductive grinding wheel is trimmed until the machining gap exceeds the discharge gap; Step 7), adjusting the position of the metal-based CBN conductive grinding wheel by a numerically controlled grinder so that a radial circumferential surface of the abrasive layer of the metal-based CBN conductive grinding wheel and the copper sample maintain a discharge gap; Step 8), repeat step 6) to step 7), until the radial circumferential surface of the abrasive layer of the metal-based CBN conductive grinding wheel is finished.

[0006] As a further optimization scheme of the process method for discharge electrolysis dressing of metal-based CBN conductive grinding wheels of the present invention, the voltage of the power supply in step 2) is set to 1-15V.

[0007] As a further optimization scheme of the process method for discharge electrolysis dressing of metal-based CBN conductive grinding wheels of the present invention, the electrolyte is a 5wt.% NaCl solution, and the temperature is maintained at 30°C.

[0008] As a further optimization scheme of the process method for discharge electrolysis dressing of metal-based CBN conductive grinding wheels of the present invention, in the steps 3) and 6), the rotation speed of the metal-based CBN conductive grinding wheel is not less than 300 rpm, and the axial speed during reciprocating motion is not less than 10 mm / min.

[0009] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects: The present invention designs a process method for dressing a metal-based CBN conductive grinding wheel by discharge electrolysis. In view of the high conductive strength and hardness of the metal-based CBN, the conductive grinding wheel is used as an anode and the copper sample is used as a cathode. Material removal is achieved through the discharge electrolysis between the copper sample and the conductive grinding wheel. The discharge action can remove the metal matrix and CBN abrasive grains, while the electrolysis action can remove the metal matrix so that the abrasive grains have a certain protruding height. The dressed conductive grinding wheel can simultaneously achieve the grinding action of the end face and the radial circumferential surface, and can process structures such as steps. The present invention effectively reduces the dressing efficiency and cost of the metal-based CBN conductive grinding wheel. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the structure when the present invention is implemented; Figure 2 It is a cross-sectional view of the metal-based CBN conductive grinding wheel of the present invention.

[0011] In the figure, 1-CNC grinder, 2-metal-based CBN conductive grinding wheel, 3-copper sample, 4-machine tool worktable, 5-mechanical vise, 6-flexible nozzle, 7-rotating spindle of CNC grinder, 8-lower end surface of abrasive layer of metal-based CBN conductive grinding wheel, 9-radial circumferential surface of abrasive layer of metal-based CBN conductive grinding wheel. DETAILED DESCRIPTION

[0012] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings: The present invention can be implemented in many different forms and should not be considered to be limited to the embodiments described herein. On the contrary, these embodiments are provided to make this disclosure thorough and complete, and will fully express the scope of the present invention to those skilled in the art. In the accompanying drawings, components are enlarged for clarity.

[0013] like Figure 1 As shown, the present invention discloses a process for dressing a metal-based CBN conductive grinding wheel by discharge electrolysis, comprising the following steps: Step 1), the metal-based CBN conductive grinding wheel and the rotating spindle of the CNC grinder are coaxially fixedly connected, and the CNC grinder realizes its reciprocating movement in the X, Y, and Z axes and the rotational movement in the Z axis; the copper sample is clamped and fixed on the machine tool workbench by a mechanical bench clamp, and the electrolyte in the processing area is provided by a flexible nozzle capable of adjusting the angle; the rotating spindle of the CNC grinder is perpendicular to the machine tool workbench; the copper sample is a rectangular plate, and its length direction is the X-axis direction, the width direction is parallel to the axis of the rotating spindle of the CNC grinder and is the Z-axis direction, and the direction perpendicular to the copper sample is the Y direction; the width of the copper sample is greater than or equal to the thickness of the metal-based CBN conductive grinding wheel; Step 2), connect the metal-based CBN conductive grinding wheel to the positive electrode of the power supply, and connect the copper sample to the negative electrode of the power supply, to ensure that the flexible nozzle supplies electrolyte to the processing area at a constant electrolyte pressure; the voltage of the power supply is set to 1-15V; the electrolyte uses a 5wt.% NaCl solution, maintains a temperature of 30°C, and the electrolyte pressure is not less than 0.1MPa; Step 3), the position of the metal-based CBN conductive grinding wheel is adjusted by a CNC grinder, so that the center of the copper sample and the metal-based CBN conductive grinding wheel are coplanar, and the lower end surface of the abrasive layer of the metal-based CBN conductive grinding wheel is directly above the copper sample, and a discharge gap is maintained between the two. The metal-based CBN conductive grinding wheel is controlled by the CNC grinder to rotate at a high speed and reciprocate along the X-axis direction to achieve discharge electrolysis in the electrolyte provided by the flexible nozzle. Figure 2 The lower end surface of the abrasive layer of the metal-based CBN conductive grinding wheel shown is trimmed until the machining gap exceeds the discharge gap; Step 4), adjusting the position of the metal-based CBN conductive grinding wheel by a CNC grinder so that the lower end surface of the abrasive layer of the metal-based CBN conductive grinding wheel and the copper sample maintain a discharge gap; Step 5), repeating steps 3) to 4), until the lower end surface of the abrasive layer of the metal-based CBN conductive grinding wheel is finished; Step 6), the position of the metal-based CBN conductive grinding wheel is adjusted by a CNC grinder, so that the center of the copper sample and the metal-based CBN conductive grinding wheel are coplanar, the radial circumferential surface of the metal-based CBN conductive grinding wheel corresponds to the width of the copper sample and a discharge gap is maintained between the two, and the metal-based CBN conductive grinding wheel is controlled by the CNC grinder to rotate at a high speed and to reciprocate along the Z-axis direction, and discharge electrolysis is achieved in the electrolyte provided by the flexible nozzle, such as Figure 2 The radial circumferential surface of the abrasive layer of the metal-based CBN conductive grinding wheel shown is trimmed until the machining gap exceeds the discharge gap; Step 7), adjusting the position of the metal-based CBN conductive grinding wheel by a numerically controlled grinder so that a radial circumferential surface of the abrasive layer of the metal-based CBN conductive grinding wheel and the copper sample maintain a discharge gap; Step 8), repeat step 6) to step 7), until the radial circumferential surface of the abrasive layer of the metal-based CBN conductive grinding wheel is finished.

[0014] In step 3) and step 6), the rotation speed of the metal-based CBN conductive grinding wheel is not less than 300 rpm, and the axial speed during reciprocating motion is not less than 10 mm / min.

[0015] During the discharge electrolytic dressing process, the discharge action can simultaneously remove the metal matrix and CBN abrasive grains of the metal-based CBN conductive grinding wheel to ensure the dimensional accuracy of the dressed surface, while the electrolytic action can remove the metal matrix of the metal-based CBN conductive grinding wheel to ensure that the abrasive grains have a certain protruding height. The dressed metal-based CBN conductive grinding wheel can simultaneously grind the end face and radial circumferential surface, and can be used to process structures such as steps, effectively reducing costs and improving dressing efficiency.

[0016] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0017] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A process for dressing a metal-based CBN conductive grinding wheel by discharge electrolysis, characterized in that: The following steps are involved: Step 1), the metal-based CBN conductive grinding wheel and the rotating spindle of the CNC grinder are coaxially fixedly connected, and the CNC grinder realizes its reciprocating movement in the X, Y, and Z axes and the rotational movement in the Z axis; the copper sample is clamped and fixed on the machine tool workbench by a mechanical bench clamp, and the electrolyte in the processing area is provided by a flexible nozzle capable of adjusting the angle; the rotating spindle of the CNC grinder is perpendicular to the machine tool workbench; the copper sample is a rectangular plate, and its length direction is the X-axis direction, the width direction is parallel to the axis of the rotating spindle of the CNC grinder and is the Z-axis direction, and the direction perpendicular to the copper sample is the Y direction; the width of the copper sample is greater than or equal to the thickness of the metal-based CBN conductive grinding wheel; Step 2), connect the metal-based CBN conductive grinding wheel to the positive electrode of the power supply, and connect the copper sample to the negative electrode of the power supply, to ensure that the flexible nozzle supplies electrolyte to the processing area at a constant electrolyte pressure; Step 3), adjusting the position of the metal-based CBN conductive grinding wheel by a numerically controlled grinder, so that the center of the copper sample and the metal-based CBN conductive grinding wheel are coplanar, and the lower end surface of the abrasive layer of the metal-based CBN conductive grinding wheel is directly above the copper sample, and a discharge gap is maintained between the two, and the metal-based CBN conductive grinding wheel is controlled by the numerically controlled grinder to rotate at a high speed and to perform a cyclic reciprocating motion along the X-axis direction, and discharge electrolysis is realized in the electrolyte provided by the flexible nozzle, and the lower end surface of the abrasive layer of the metal-based CBN conductive grinding wheel is trimmed until the processing gap exceeds the discharge gap; Step 4), adjusting the position of the metal-based CBN conductive grinding wheel by a CNC grinder so that the lower end surface of the abrasive layer of the metal-based CBN conductive grinding wheel and the copper sample maintain a discharge gap; Step 5), repeating steps 3) to 4), until the lower end surface of the abrasive layer of the metal-based CBN conductive grinding wheel is finished; Step 6), adjusting the position of the metal-based CBN conductive grinding wheel by a numerically controlled grinder, so that the center of the copper sample and the metal-based CBN conductive grinding wheel are coplanar, the radial circumferential surface of the metal-based CBN conductive grinding wheel corresponds to the width of the copper sample and a discharge gap is maintained between the two, the metal-based CBN conductive grinding wheel is controlled by the numerically controlled grinder to rotate at a high speed and to perform a cyclic reciprocating motion along the Z-axis direction, discharge electrolysis is achieved in the electrolyte provided by the flexible nozzle, and the radial circumferential surface of the abrasive layer of the metal-based CBN conductive grinding wheel is trimmed until the machining gap exceeds the discharge gap; Step 7), adjusting the position of the metal-based CBN conductive grinding wheel by a numerically controlled grinder so that a radial circumferential surface of the abrasive layer of the metal-based CBN conductive grinding wheel and the copper sample maintain a discharge gap; Step 8), repeat step 6) to step 7), until the radial circumferential surface of the abrasive layer of the metal-based CBN conductive grinding wheel is finished.

2. The process for dressing a metal-based CBN conductive grinding wheel by discharge electrolysis according to claim 1, characterized in that: In step 2), the voltage of the power supply is set to 1-15V.

3. The process for dressing a metal-based CBN conductive grinding wheel by discharge electrolysis according to claim 1, characterized in that: The electrolyte is a 5 wt.% NaCl solution, and the temperature is maintained at 30°C.

4. The process for dressing a metal-based CBN conductive grinding wheel by discharge electrolysis according to claim 1, characterized in that: In the steps 3) and 6), the rotation speed of the metal-based CBN conductive grinding wheel is not less than 300 rpm, and the axial speed during reciprocating motion is not less than 10 mm / min.

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