Discrete edge end mill wear on-machine measurement assistive device and method

Abstract

The invention discloses an on-machine measurement assistive device and method for abrasion of a discrete edge end mill. The auxiliary tool comprises a fixing clamp, a worm and gear and rack composite lifting mechanism, a bevel gear driven pivotal bearing mechanism, a camera platform, an industrial camera and a laser gradienter. The fixing clamp comprises a bolt and a gasket; the invention discloses a worm and gear and rack composite lifting mechanism. A bevel gear drives a pivotal bearing mechanism. The measuring method comprises the following steps: vertically lifting and positioning the camera platform by driving the worm and gear mechanism; horizontal rotation positioning of the camera platform is achieved by driving the bevel gear mechanism, the laser gradienter provides position reference, the industrial camera collects cutter abrasion images, and the image processing unit analyzes and processes the collected images and calculates abrasion loss. On-machine real-time monitoring of abrasion of the discrete edge end mill can be achieved, automatic abrasion measurement of chip separating grooves of different heights is completed, frequent manual adjustment is avoided, and the measurement precision and reliability are improved.

Description

Technical Field

[0001] The present invention belongs to the field of metal processing, and more specifically, relates to an auxiliary tool and method for measuring the wear of discrete-edge end mills on a machine. Background Art

[0002] CNC milling technology is widely used in modern manufacturing, and tool wear is a key factor affecting machining quality and production efficiency. Discrete-edge end mills, as cutting tools with complex geometries, are directly affected by flank wear and chip wear, which directly determine cutting performance, machining accuracy, and workpiece surface quality.

[0003] Currently, tool wear detection primarily relies on offline testing, which involves removing the tool from the machine tool spindle and measuring wear using a microscope or industrial camera. This method presents the following technical challenges: low detection efficiency and the need to stop the machine to remove the tool, impacting production continuity; frequent removal and re-clamping operations can easily lead to clamping errors, affecting machining accuracy; and the inability to monitor tool wear in real time, making it difficult to detect abnormal tool wear in a timely manner.

[0004] With the development of machine vision technology, tool wear detection methods based on visual recognition are gaining popularity. However, existing visual inspection technologies still face technical limitations when used with discrete-edge end mills. Discrete-edge end mills have complex chip groove geometry, making it difficult for existing visual recognition algorithms to accurately identify and measure chip groove wear. Optical interference factors such as reflections and shadows on the tool surface affect visual inspection accuracy. Furthermore, there is a lack of specialized detection devices and measurement methods tailored to the structural characteristics of discrete-edge end mills. Therefore, there is an urgent need to develop an on-machine wear detection technology that can adapt to the complex structural characteristics of discrete-edge end mills, enabling rapid and accurate tool wear monitoring and improving the intelligent level of CNC machining.

[0005] In response to the above problems, the present invention proposes an on-machine measurement aid for discrete edge end mill wear, which can quickly measure the wear of the back face and chip groove of the discrete edge end mill during the machining gap without disassembling the tool, significantly improving the measurement efficiency and proposing an effective solution for real-time monitoring of the wear of discrete edge end mills. Summary of the Invention

[0006] The present invention provides an on-machine measurement auxiliary tool for discrete edge end mill wear, which includes a fixing fixture, a bevel gear driven rotary bearing system, a worm gear and rack composite lifting mechanism, and a measuring mechanism; the fixing fixture is fixed to a machine tool workbench, and two worm gear and rack composite lifting mechanisms are matched with the fixing fixture device, and then the bevel gear driven rotary bearing system is lifted and fixed, and the measuring mechanism is placed on a horizontal rotating platform; the mechanism for realizing vertical movement includes a worm gear and a rack, and the worm gear assembly converts the rotational motion into linear motion, driving the rack component to vertically and precisely displace; the worm gear serves as the power end, and vertical movement is realized through the execution of the mechanism; the horizontal rotating mechanism includes a bevel gear and a bearing matching platform, and an auxiliary camera is used to measure the wear values ​​of the back tool face and chip groove on each cutting edge.

[0007] The discrete edge end mill is a wear measurement aid designed for discrete chip grooves of a certain size and position on the peripheral edge of a traditional end mill, so as to realize wear measurement of the discrete edge end mill.

[0008] The industrial camera and infrared laser face the center of the bevel gear driven rotary bearing system and keep the center in the same straight line with the center of the tool tip of the discrete edge end mill.

[0009] The present invention provides a method for using an on-machine wear measuring tool for discrete-edge end mills, specifically as follows:

[0010] Step 1: Select a discrete-edge end mill with a certain structure, adjust the motor to drive the worm gear to drive the detection platform to a position flush with the discrete-edge end mill, and use infrared laser to monitor whether it is aligned.

[0011] Step 2: Control the tool to perform cutting processing, stop processing every 3 minutes, and restore it to the original position and align it.

[0012] Step 3: Use the motor to drive the bevel gear to rotate, causing the camera to rotate circumferentially to collect wear images. After completing the wear image collection at this height, the motor drives the worm to rotate the worm wheel to move vertically and perform circumferential measurement at the next height. Compared with the existing technology, this invention has the following advantages:

[0013] (1) Highly targeted: It is specially designed for the complex geometric structure characteristics of discrete edge end mills, and can effectively adapt to their special chip grooves and flank geometry, solving the technical problem that existing detection methods cannot accurately measure the wear of discrete edge end mills.

[0014] (2) On-machine measurement function: It realizes on-machine detection of tool wear without removing the tool from the machine tool spindle, avoiding clamping errors caused by frequent disassembly and assembly, and significantly improving measurement efficiency and production continuity.

[0015] (3) Multi-dimensional motion control: A worm gear and rack-and-pinion composite lifting mechanism is used to achieve precise vertical positioning of the Z axis, and a bevel gear-driven rotary bearing mechanism is used to achieve rotational motion in the XY plane. The two sets of mechanisms work in coordination and can fully measure the chip grooves and back cutting surfaces of discrete edge end mills at different heights and angles.

[0016] (4) High degree of automation: The camera platform is automatically positioned and moved by motor drive, and the laser level provides an accurate position reference, which reduces manual intervention and improves the automation level and repeatability of the measurement.

[0017] (5) High measurement accuracy: A dedicated calibration method is provided, which, combined with industrial cameras and image processing technology, can quickly and accurately obtain tool wear data, providing reliable technical support for real-time monitoring and prediction of tool wear status.

[0018] (6) Wide applicability: The device has a compact structure and can be easily installed on different types of CNC machine tool workbenches through a fixing fixture. It has good versatility and promotion and application value.

[0019] Figures in the specification

[0020] Figure 1 This is the overall assembly diagram of the on-machine measuring aid of the present invention;

[0021] Figure 2 This is a schematic diagram of the horizontal rotation structure of the on-machine measuring auxiliary tool of the present invention;

[0022] Figure 3 It is a schematic diagram of the vertical structure of the on-machine measuring auxiliary tool of the present invention;

[0023] Figure 4 It is the overall flow chart of the measuring method of the present invention;

[0024] Figure 5 It is a schematic structural diagram of the discrete-edge end mill targeted by the present invention;

[0025] Figure 6 is a workflow diagram of the wear image processing unit of the present invention;

[0026] Figure 7 The invention relates to grayscale processing and wear calibration for discrete-edge end mill wear in the method of use. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings.

[0028] like Figure 5The figure shows the structure of a discrete-edge end mill. Discrete-edge end mills feature chip flutes on the spiral cutting edge to improve chip evacuation, reduce cutting vibration, and increase machining efficiency. However, due to their unique structure, the wear values ​​of both the chip flute and the flank face cannot be measured simultaneously on-machine. This invention proposes an on-machine wear measurement tool for discrete-edge end mills that enables rapid on-machine measurement of both the chip flute and the flank face. The tool's main material is 45# steel.

[0029] The bevel gear driven rotary bearing mechanism (2) and the worm gear and rack and pinion composite lifting mechanism (3) in the present invention are driven by a stepping motor.

[0030] like Figure 1 The figure shows a discrete edge end mill wear on the machine measuring auxiliary tool. The fixing fixture is fixed to the workbench by bolts, and then the worm gear and gear rack composite lifting mechanism is fixed to the fixture by a matching method to ensure the stability of the device; the bevel gear drives the rotary bearing mechanism and the measuring mechanism to be fixed together by matching. The measuring mechanism is provided with a camera fixture, and the industrial camera is fixed to the measuring platform through a snap-on design.

[0031] The worm gear and rack composite lifting mechanism (3) is composed of a worm gear and a rack. The worm gear is driven by a motor to drive the worm gear and the rack to move. The worm gear is fixed in the housing 3-4 after being engaged with the rack. The housing 3-4 is fixed to the worm gear by using a matching mechanism 3-3. The bevel gear driving rotary bearing mechanism (2) is driven to rotate by the bevel gear.

[0032] When collecting on-machine wear images of the tool, first return the discrete-edge end mill to its original position, align the center of the bevel gear-driven slewing bearing mechanism with the center of the tool, and perform optical calibration on the industrial camera to enable it to collect clear wear images. After alignment, drive the tool to cut, and return to the original position to collect images every three minutes.

[0033] The wear amount is calculated by image size conversion. This conversion is measured after the tool is horizontally aligned. The length of each gray block on the standard card is 10 mm. The number of pixels on the standard card is obtained through software processing, and the conversion ratio is calculated using the following formula:

[0034]

[0035] Among them, L is the conversion ratio, and D is the number of pixels occupied by the standard card.

[0036] The motor then drives the bevel gear to rotate, collecting an image every 90°. The image is processed by the processing unit and the wear value is output. After each image is completed, the next blade is photographed. After the circumferential image is completed, the worm is driven to drive the worm wheel and rack to move according to the height displacement set according to the discreteness of the chip groove.

[0037] like Figure 6 The image processing flow is shown in Figure 2. Figure 7 When the image acquisition is completed, it is transmitted to the image processing unit through the camera Bluetooth transmission module. The processing unit includes: grayscale processing module, wear calibration module, and wear output module. After the grayscale processing module processes the image, the original image is grayscaled to enhance the contrast of the worn area, and the wear value is calibrated and calculated. The output wear value should be increased on the basis of the previous one. If it does not conform to the physical laws, it needs to be re-measured.

[0038] Those skilled in the art will readily understand that the above description is not intended to limit the present invention, and any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An on-machine wear measuring tool for discrete edge end mills, characterized by: The discrete edge end mill wear on-machine measuring auxiliary tool comprises: a fixing fixture (1), a bevel gear driven rotary bearing mechanism (2), a worm gear and rack composite lifting mechanism (3), and a measuring mechanism (4), wherein the fixing fixture is composed of a cylinder (1-1), a threaded structure (1-2), a clamping block (1-3), and a bolt (1-4); the bevel gear driven rotary bearing system is composed of a rolling bearing (2-1), a rotating platform (2-2), and a pair of vertically placed bevel gears (2-3); the worm gear and rack composite lifting mechanism is composed of a worm gear (3-1), a rack (3-2), a matching mechanism (3-3), and a housing (3-4); and the measuring mechanism is composed of an industrial camera (4-1), a camera fixture (4-2), and an infrared laser (4-3).

2. The on-machine wear measuring aid for discrete edge end mills according to claim 1, characterized in that: The fixing fixture (1) is fixed to the machine tool workbench (5), and two worm gear rack composite lifting mechanisms (3) are matched with the fixing fixture device (1), and then the bevel gear driven rotary bearing system (2) is lifted and fixed, and the measuring mechanism is placed on the horizontal rotating platform; the vertical direction moving mechanism includes a worm gear and rack composite lifting mechanism including a worm gear assembly, a rack component and an adapter mechanism, and the worm gear assembly converts the rotary motion into linear motion, and drives the rack component to move vertically with precision; the worm gear serves as the power end, and realizes vertical movement through the execution of the mechanism; the horizontal rotating mechanism includes a bevel gear and a bearing bearing platform, and the auxiliary camera measures the wear value of the back face and the chip groove on each cutting edge.

3. The on-machine wear measuring aid for discrete edge end mills according to claim 1, characterized in that: The industrial camera (4-1) and the infrared laser (4-3) face the center of the bevel gear driven slewing bearing system (2), and keep the center and the tip center of the discrete edge end mill in the same straight line.

4. A method for using an on-machine wear measuring aid for discrete edge end mills according to claim 1, characterized in that: include: Achieve horizontal alignment and focal length adjustment between the auxiliary tool and the discrete edge end mill tip; Control the tool to cut the workpiece according to the specified path; After cutting, the tool returns to its initial position, and the auxiliary tool moves vertically and horizontally to collect tool wear images; The acquired original wear image is transmitted to the processing unit via Bluetooth for grayscale processing, pixel calibration, wear value calculation, and output of the wear amount.

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