A high-efficiency processing method for V-shaped grooves on the working roll surface of a chilled cast iron roll

Abstract

This invention proposes an efficient method for machining V-grooves on the working surface of chilled cast iron rollers, belonging to the field of rubber and plastic machining technology. The method improves machining rigidity by changing the tool's machining position and shortening the spindle extension length; it reduces the cutting depth and area by changing the inclined surface machining method to a face milling method, thereby reducing the tool's cutting force; and it alters the cutting force on the tool, preventing the tool from pressing against the right-angled edge of the V-groove, thus avoiding tooth breakage, improving the groove's surface roughness, increasing tool life, and improving machining efficiency.

Description

Technical Field

[0001] This invention belongs to the field of rubber and plastic machining technology, and relates to an efficient method for machining V-grooves on the working surface of chilled cast iron rollers. Background Technology

[0002] Chilled cast iron rollers are core components in various products such as rubber and plastic open mills, extrusion sheeting machines, and calenders. Their working roller surfaces have a white iron structure with a surface hardness of 53-56 HRC and are highly brittle. With the development of the domestic rubber and plastics machinery industry, orders for open mills and sheeting machines are increasing year by year, and the production volume of V-groove rollers is also increasing annually. These rollers have a unique groove structure with angles ranging from 68° to 60°, and the number can reach 150-200. The original machining method involved using a boring machine with a forming disc milling cutter to machine the top of the roller surface. The main problems with this original method are as follows:

[0003] 1) Multiple "tooth breakage" phenomena are very likely to occur at the sharp angle of the straight edge at the top of the roller groove, resulting in a defect rate of over 50% after processing.

[0004] 2) The design requirement for the surface roughness of the roller groove is Ra3.2μm, but the actual roughness after machining is between Ra6.3μm and Ra12.5μm, which does not meet the requirements of the drawing.

[0005] 3) Self-made forming disc milling cutters have high wear, low durability, require frequent re-grinding, and have a short service life.

[0006] 4) Extremely low processing efficiency. The original processing method involved machining from the top of the roller. Due to the high surface hardness and brittleness of the roller, the cutting speed was low, and the self-made forming disc milling cutter suffered from rapid wear and poor durability. The cutter needed to be re-sharpened after every few grooves machined, frequently resulting in situations where the roller was being processed while the cutter was still being re-sharpened. Under normal circumstances, machining one roller groove takes about 15 days. If defective products are found or the cutter is not re-sharpened in time, the processing cycle can extend to nearly a month. These problems severely impact product quality and production schedules, making it impossible to meet customer requirements. The machining of these roller V-grooves has become a processing bottleneck, urgently requiring the development of a more efficient machining method to solve this problem. Summary of the Invention

[0007] To address the aforementioned problems in the prior art, this invention proposes an efficient machining method for V-grooves on the working surface of chilled cast iron rollers. This method replaces the original machining at the top of the roller with machining at a specific angle on the side of the roller, shortening the spindle extension length and improving machining rigidity. By improving the cutting edge machining method, the inclined surface machining method is changed to a face milling method, reducing the cutting depth and area, and lowering the cutting force. The cutting force on the tool is altered so that the tool does not press against the right-angled edge of the V-groove, thus avoiding tooth breakage. This achieves improved V-groove accuracy, surface roughness meeting design requirements, increased tool life, and improved machining efficiency, ultimately reducing costs and increasing efficiency.

[0008] The technical solution of this invention is as follows:

[0009] A method for efficiently machining V-grooves on the working surface of chilled cast iron rollers includes the following steps:

[0010] Step 1: Clamp the roller using an indexing mechanism, idler rollers, and center.

[0011] Step 2: Use a dial indicator to align the rollers, checking the top and side busbars to ensure that the straightness of the top and side busbars is within 0.05 mm.

[0012] Step 3: Based on the angle α of the V-groove, move the machining tool to the (90-α) position on the side of the roller for machining. This includes the following steps:

[0013] Step 3.1: Using the roller side generatrix as the Y-axis zero point, translate the cutting tool tip along the Y-axis by a distance of _____.

[0014] Y = cosα × R, where α is the V-groove angle and R is the roller radius.

[0015] Step 3.2: After moving the tool tip by the Y-axis distance, move the Z-axis. Set the Z-axis zero point when the tool tip contacts the roller surface.

[0016] Step 3.3: The Z-axis movement distance is calculated based on the depth of the V-groove on the roller and the machining allowance on the roller surface.

[0017] Step 4: Machining the V-groove on the roller. The machining tool starts from the end face of the roller and uses climb milling. The cutting parameters are: cutting speed Vc = 150~200m / min, feed per tooth fz = 0.15~0.2mm / r, and the cutting depth is selected according to the groove depth and the machining allowance of the roller surface. A cutting depth ap = 1~3mm can be used.

[0018] Step 5: After processing each groove, the indexing mechanism rotates the roller to process the next groove, ensuring uniform indexing and consistent groove spacing.

[0019] Furthermore, when the tool for machining grooves is just entering the groove and about to exit after machining a groove, the cutting parameters should be reduced by 50% to prevent vibration caused by intermittent cutting, which could lead to chipping of the groove teeth and damage to the tool.

[0020] The beneficial effects of this invention are as follows: This invention improves machining rigidity by changing the tool machining position and shortening the spindle extension length; it changes the inclined surface machining method to a face milling method to reduce the cutting depth and area and the tool cutting force; it changes the cutting force on the tool so that the tool cannot squeeze the right angle edge of the V-shaped groove of the part, avoids groove chipping, improves the groove machining roughness, increases tool life, and improves machining efficiency. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the distribution of V-shaped grooves on the roller surface.

[0022] Figure 2 The original machining method and the efficient machining method of the present invention are compared. The cutting depths of the two methods are ap1 and ap2, respectively; the contact areas are S1 and S2, respectively; and the force directions are F1 and F2, respectively. Detailed Implementation

[0023] The method of the present invention will be further described below with reference to the accompanying drawings in this embodiment.

[0024] A method for efficiently machining V-grooves on the working surface of chilled cast iron rollers includes the following steps:

[0025] Step 1: Clamp the roller using an indexing mechanism, idler rollers, and center.

[0026] Step 2: Use a dial indicator to align the rollers, checking the top and side busbars to ensure that the straightness of the top and side busbars is within 0.05 mm.

[0027] Step 3: Based on the angle α of the V-groove, move the machining tool to the side of the roller at the position (90-α) for machining.

[0028] Step 3.1: Using the roller side generatrix as the Y-axis zero point, translate the cutting tool tip along the Y-axis by a distance of _____.

[0029] Y = cosα × R, where α is the V-groove angle and R is the roller radius.

[0030] Step 3.2: After moving the tool tip by the Y-axis distance, move the Z-axis. Set the Z-axis zero point when the tool tip contacts the roller surface.

[0031] Step 3.3: The Z-axis movement distance is calculated based on the depth of the V-groove on the roller and the machining allowance on the roller surface.

[0032] Step 4: Machining the V-groove on the roller. The machining tool starts from the end face of the roller and uses climb milling. The cutting parameters are: cutting speed Vc = 160 m / min, feed per tooth fz = 0.16 mm / r, and depth of cut ap = 2 mm.

[0033] Step 5: When machining a groove, the cutting parameters should be reduced by 50% when the tool is just entering the groove and when it is about to exit the groove after machining a groove. This is to prevent the tool from vibrating due to intermittent cutting, which could cause chipping of the groove teeth and damage to the tool.

[0034] Step 6: After each groove is processed, the indexing mechanism is used to rotate the rollers to process the next groove, ensuring uniform indexing and consistent groove spacing.

[0035] like Figure 2 As shown, compared with the original processing method, the cutting depth ap2 of the present invention is reduced by 10% compared with ap1; the contact area S2 is reduced by 50% compared with S1; the cutting force is reduced during the processing of the present invention, which reduces tool wear, increases tool life, and improves processing efficiency; the force direction F2 is perpendicular to the right-angle side of the roller groove and away from the right-angle side, and F1 is perpendicular to the inclined side of the roller groove and towards the right-angle side; during the processing of the present invention, the force direction of the tool is away from the right-angle side, the tool cannot squeeze the right-angle side, avoids the groove chipping phenomenon, and improves the groove processing quality.

Claims

1. A method for efficiently machining V-grooves on the working surface of chilled cast iron rollers, characterized in that, The method includes the following steps: Step 1: Clamp the roller using an indexing mechanism, idler rollers, and center. Step 2: Use a dial indicator to align the rollers, checking the top and side busbars of the rollers to ensure that the straightness of the top and side busbars is within 0.05 mm; Step 3: Based on the angle α of the V-groove, move the machining tool to the position 90-α on the side of the roller for machining; Step 3.1: Using the roller side generatrix as the Y-axis zero point, translate the cutting tool tip along the Y-axis by a distance of _____. Y = cosα × R, where α is the V-groove angle and R is the roller radius; Step 3.2: After moving the tool tip by the Y-axis distance, move the Z-axis. Set the Z-axis zero point when the tool tip contacts the roller surface. Step 3.3: The Z-axis travel distance is calculated based on the depth of the V-groove on the roller and the machining allowance on the roller surface; Step 4: Machining the V-groove on the roller. The machining tool starts from the end face of the roller and uses climb milling. The cutting parameters are: cutting speed Vc = 150~200m / min, feed per tooth fz = 0.15~0.2mm / r, and the cutting depth is selected according to the groove depth and the machining allowance of the roller surface. Step 5: After processing each groove, the indexing mechanism rotates the roller to process the next groove, ensuring uniform indexing and consistent groove spacing.

2. The efficient machining method for V-grooves on the working surface of a chilled cast iron roller according to claim 1, characterized in that, In step 4, the cutting depth ap = 1~3mm.

3. The efficient machining method for V-grooves on the working surface of a chilled cast iron roller according to claim 1, characterized in that, When machining grooves, the cutting parameters should be reduced by 50% when the tool is just entering the groove or when it is about to exit the groove after machining a groove. This is to prevent vibration caused by intermittent cutting, which could lead to chipping of the groove teeth and damage to the tool.

4. The efficient machining method for V-grooves on the working surface of a chilled cast iron roller according to claim 2, characterized in that, When machining grooves, the cutting parameters should be reduced by 50% when the tool is just entering the groove or when it is about to exit the groove after machining a groove. This is to prevent vibration caused by intermittent cutting, which could lead to chipping of the groove teeth and damage to the tool.

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