阅读说明：本技术 一种立铣刀在机磨损检测装置 (End mill on-machine abrasion detection device ) 是由 刘少洋 刘献礼 张博闻 王志学 于 2021-08-23 设计创作，主要内容包括：本专利公开了一种立铣刀磨损在机检测装置,包括基座、传动系统、磁场检测系统、位置检测系统、信号处理系统。所述的传动系统包括手轮、蜗轮、蜗杆和支架,用于固定和驱动磁场检测装置。所述磁场检测系统包括激励线圈、磁芯和磁场传感器,激励线圈在检测区域产生交变磁场,铣刀处于交变磁场中时产生感应电流,由于集肤效应,交变电流主要集中于铣刀表面；当刀具发生磨损时,切削刃附近的感应电流分布发生变化,从而改变磁场的分布,传感器通过检测铣刀的感应磁场来复映刀具的磨损边界。所述位置检测系统包括红外感应器和角位移传感器,位置传感器用于标定铣刀的位置,角位移传感器用于记录磁场检测系统的角度。所述的信号处理系统包括前置放大电路、信号调节电路、信号处理电路和显示控制电路,用于处理和分析所测信号。本发明适合在机检测立铣刀的磨损,避免了铣刀的装夹所消耗的时间,提高了生产效率；同时避免了由于铣刀拆装产生的误差,提高了检测精度,保证了加工生产的稳定性。(The patent discloses an end mill wearing and tearing are at quick-witted detection device, including base, transmission system, magnetic field detecting system, position detecting system, signal processing system. The transmission system comprises a hand wheel, a worm and a bracket and is used for fixing and driving the magnetic field detection device. The magnetic field detection system comprises an excitation coil, a magnetic core and a magnetic field sensor, wherein the excitation coil generates an alternating magnetic field in a detection area, the milling cutter generates an induced current when positioned in the alternating magnetic field, and the alternating current is mainly concentrated on the surface of the milling cutter due to the skin effect; when the cutter is worn, the distribution of induced current near the cutting edge changes, so that the distribution of magnetic field is changed, and the sensor detects the induced magnetic field of the milling cutter to reflect the wear boundary of the cutter. The position detection system comprises an infrared sensor and an angular displacement sensor, the position sensor is used for calibrating the position of the milling cutter, and the angular displacement sensor is used for recording the angle of the magnetic field detection system. The signal processing system comprises a pre-amplification circuit, a signal regulating circuit, a signal processing circuit and a display control circuit and is used for processing and analyzing the measured signal. The invention is suitable for detecting the abrasion of the end mill on machine, avoids the time consumed by clamping the end mill, and improves the production efficiency; meanwhile, errors caused by disassembly and assembly of the milling cutter are avoided, the detection precision is improved, and the stability of processing production is ensured.)

1. The utility model provides an end mill is at quick-witted wear detection device which characterized in that: the magnetic field detection device mainly comprises a base, a transmission system, a magnetic field detection system, a position detection system and a signal processing system, wherein the base (1) is fixed on a workbench of a machine tool through a T-shaped groove at the bottom; the transmission system is arranged on the base (1); the magnetic field detection device is fixed on the bracket (6); the position detection device is mounted on the base (1).

2. The transmission system according to claim 1 comprises a hand wheel (2), a worm (4), a worm wheel (5) and a support (6), wherein the worm wheel (5) is connected with the base (1) through a thrust bearing, a sliding groove is formed in the worm wheel (5), a horizontal scale is arranged on the sliding groove, the worm (4) is installed on a bearing seat (3) and meshed with the worm wheel (5), and the hand wheel (2) is fixedly connected with the worm (4).

3. The bracket (6) of claim 2 is used for fixing the magnetic field detection device, the bottom of the bracket is fixed in a sliding groove of the worm wheel (5) by a locking device, the height of the bracket (6) can be adjusted, and a scale is engraved on the bracket (6) and used for recording the height of the magnetic field detection device.

4. The magnetic field detection device according to claim 1 comprises a rectangular excitation coil (7), a magnetic core (8) and a magnetic field sensor (9), wherein the rectangular excitation coil (7) is provided with 12V sinusoidal alternating current, the magnetic core (8) is added into the excitation coil in order to generate a uniform excitation magnetic field, the magnetic field sensor (9) is fixed in the center of the magnetic core (8), a single-layer coil is uniformly wound on the magnetic core, and the output end of each coil is connected with the input end of the signal processing system.

5. The signal processing system of claim 1, comprising a pre-amplification circuit, a signal conditioning circuit, a signal processing circuit, a display control circuit.

6. The position detection system according to claim 1, comprising an infrared sensor (10) and an angular displacement sensor (12), the infrared sensor (10) being fixed to a worm shaft end cap (11) of the transmission for detecting the position of the tool; the angular displacement sensor (12) is fixed on the base (1) to measure the rotation angle of the worm wheel (5); the data signal output ends of the infrared sensor (11) and the angular displacement sensor (12) are connected with the data receiving end of the signal processing system.

Technical Field

The invention relates to a machining detection device, in particular to an on-machine detection device for the abrasion state of an end mill, which can realize on-machine detection.

Background

With the rapid development of machining technology, the requirements on machining precision in the aspects of aerospace, automobiles, machine tools, part machining and the like are higher and higher, and the wear of a cutter not only affects the machining precision, but also increases the manufacturing cost, affects the machining efficiency and even damages the machine tool. Since the wear on the flank face of the tool is relatively severe, the width of the flank face wear zone is usually used as a basis for judging whether the tool is worn or not.

At present, the detection of the abrasion of the cutter mostly stays at an empirical judgment stage, and whether the cutter is abraded or not is judged by judging the sound during cutting, the color of cutting chips, the roughness of a workpiece processing surface and the like. If the estimation of the service life of the cutter is too wide, the defects of the machined workpiece can be caused, the surface quality and the dimensional accuracy of the workpiece are influenced, and the defective rate is increased; if the tool life estimate is too conservative, the tool cannot be fully utilized, thereby increasing tool change times and tool cost. The other main detection method is to use a tool microscope to carry out manual detection, and has the defects that the auxiliary detection is required manually, the manpower and material resources are increased, the disassembly of a cutter is required, the procedure is complicated, and the processing efficiency is influenced.

Disclosure of Invention

In order to solve the problems of complicated cutter abrasion detection procedures, large detection error and the like, the invention designs the on-machine abrasion detection device without detaching the cutter, and the device can realize on-machine abrasion detection of the opposite milling cutter and reduce errors caused by detaching the cutter; and the abrasion value of the rear cutter face of the end mill can be automatically obtained, and the abrasion of the cutter can be measured after the signal is processed.

In order to achieve the purpose, the invention adopts the following technical scheme:

an on-machine detection device for abrasion of an end mill mainly comprises a base, a transmission system, a magnetic field detection system, a position detection system and a signal processing system. The magnetic field detection device is characterized in that the base is fixed on a machine tool workbench through a T-shaped groove, the transmission system is installed on the base, the magnetic field detection device is fixed on the support, and the position detection device is installed on the base.

The transmission system comprises a hand wheel, a worm wheel and a bracket. The worm gear device is arranged on the base through a thrust bearing and a worm gear shaft, and the worm is arranged on the bearing seat and meshed with the worm gear. The worm wheel is provided with a sliding groove, and the sliding groove is provided with a horizontal scale used for recording the distance between the end mill and the magnetic field detection system. The hand wheel is fixedly connected with the worm.

The support is fixedly connected with the magnetic field detection device, the bottom of the support is fixed with a sliding groove in the worm gear through a locking device, the height of the support can be adjusted, and a scale is engraved on the support and used for recording the height of the magnetic field detection device.

The magnetic field detection device comprises a rectangular exciting coil, a magnetic core and a magnetic field sensor, wherein 12V sinusoidal alternating current is conducted to the rectangular exciting coil, and the magnetic core is added into the exciting coil in order to generate a uniform excitation magnetic field. The magnetic field sensor is fixed in the center of the magnetic core, single-layer coils are uniformly wound on the magnetic field sensor, the output end of each coil is connected with the input end of the signal processing system, and the magnetic field size and the corresponding position height on one bus of the cutter are measured.

The signal processing system comprises a preamplifier circuit, a signal conditioning circuit, a signal processing circuit and a display control circuit. Used for processing and analyzing the signals detected by the magnetic field detection device.

The position detection system comprises an infrared sensor and an angular displacement sensor, the position sensor is fixed on a worm wheel shaft end cover of the transmission device to detect the position of a cutter, and the angular displacement sensor is fixed on the base to measure the rotation angle of the worm wheel. The data signal output ends of the position sensor and the angular displacement sensor are connected with the input end of the signal processing system.

When the device is used, the position of the milling cutter is adjusted until the infrared sensor detects that the milling cutter is positioned on the central axis of a worm wheel shaft, the positions of the bracket and the magnetic field detection device are adjusted, the worm drives the magnetic field detection device on the worm wheel to rotate around the spiral end mill for a circle by rotating the hand wheel, a magnetic field signal on the rear cutter face of the cutter is measured, and the abrasion boundary on the rear cutter face of the cutter is reflected through the distribution and the reflection of the magnetic field signal, so that the abrasion condition on the rear cutter face is detected.

Drawings

Fig. 1 is a schematic structural view of a wear detection device.

Fig. 2 is a schematic view of a stent structure.

Fig. 3 is a schematic view of a slider structure.

Fig. 4 is a block diagram of a signal processing system.

FIG. 5 is a graph of a worn end mill wear boundary remapping.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, the on-machine wear detection device for the end mill comprises a base, a transmission system, a magnetic field detection system, a position detection system and a signal processing system. The base 1 is fixed on a machine tool workbench through a T-shaped groove; the transmission system comprises a hand wheel 2, a worm 4, a worm wheel 5 and a bracket 6, wherein the worm 4 and the worm wheel 5 are arranged on the base, the hand wheel 2 is fixedly connected with the worm 5, and the bracket 6 is fixed in a chute on the worm wheel 4 through a locking device; the magnetic field detection device comprises an excitation coil 7, a magnetic core 8 and a magnetic field sensor 9, wherein the excitation coil 7 is wound on the magnetic core 8, the magnetic field sensor 9 is fixed between two ends of the magnetic core 8, the magnetic field sensor 9 consists of coils arranged in a single layer, each coil is marked with a number, a signal output end is connected with an input end of a signal processing system, and the magnetic field detection device is fixed on the worm wheel 5 through a bracket 6; the position detection device comprises an infrared sensor 10 and an angular displacement sensor 12, wherein the infrared sensor 10 is fixed on a worm gear shaft end cover 11, the angular displacement sensor 12 is fixed on the base 1, and the signal output end of the angular displacement sensor is connected with the signal input end of a signal processing system.

The structure of the bracket 6 is shown in fig. 2, and the bracket 6 mainly comprises a locking mechanism and a guide rail sliding block mechanism.

The locking mechanism comprises a locking bolt 61, a bottom plate 62 and a cylindrical sliding block 63. The bottom plate 62 is provided with a threaded hole, the width of the cylindrical sliding block 63 is the same as that of the sliding groove, the height of the cylindrical sliding block 63 is smaller than the depth of the sliding groove, the center of the cylindrical sliding block 63 is provided with a through hole, and the diameter of the through hole is equal to that of the rod part of the locking bolt 61. During installation, the bottom plate 62 is placed on the lower surface of the sliding groove, the cylindrical sliding block 63 is placed in the sliding groove, and the support guide rail 64 is placed on the upper surface of the sliding groove and connected through the locking bolt 61. Because the diameter of the cylindrical sliding block 63 is the same as the width of the sliding groove, and the height is smaller than the depth of the sliding groove, the locking bracket 6 does not move in the sliding groove under the action of friction force.

The rail-slide mechanism includes a carriage rail 64 and a slide 65. Structure of the slider 65 referring to fig. 3, the slider 65 includes a slider body 651, a locking screw 652, and a top block 653. Two ends of the sliding block body 651 are respectively provided with a cavity, the two top blocks 653 are respectively positioned in the two cavities on the sliding block body 651, the wall of each cavity is respectively provided with a through threaded hole, and the locking screw 652 is screwed into the through threaded holes. During operation, the sliding block 65 is connected with the bracket guide rail 64 through a dovetail groove, and the locking screw 652 is rotated to push the top block 653 to clamp the bracket guide rail 64, so that the sliding block 65 is locked.

The tool wear detection consists of two parts: the device comprises a signal acquisition part and a signal processing part.

Each point on the surface of the helical end mill can be represented by a cylindrical coordinate system, which is represented by the form (r, θ, z). The radius r of the cutter is kept unchanged, and the position of each point on the surface of the cutter can be obtained by measuring the rotation angle theta and the height z.

The magnetic field intensity distribution on the cutting edge of an unworn milling cutter is firstly collected as a reference. Placing the unworn end mill in a detection device, and moving the end mill until the infrared sensor 10 detects that the axis of the end mill moves to a position overlapped with the axis of the worm wheel; moving the bracket 6 in the chute, and moving the magnetic field sensor 9 to a position 1mm away from the surface of the end mill through a scale on the chute; adjusting the height of the magnetic field sensor 9 to enable the cutting edge part to be completely arranged at a position which can be detected by the magnetic field sensor 9, and recording the height y of a magnetic field detection system through a ruler on the bracket 6, wherein the magnetic field energizes the exciting coil 7 with 12V sinusoidal alternating current; the hand wheel 2 is rotated, the worm gear device drives the magnetic field detection device to rotate around the surface of the cutter for a circle, and the coils distributed in the magnetic field sensor 9 can acquire the magnetic field intensity B at different points i on each bus of the milling cutter cylinder.

In the rotation process, the magnetic field sensor 9 measures the magnetic field intensity on each bus of the milling cutter, each bus passes through a chip groove area and a cutting edge area of the milling cutter, and the distance between the magnetic field sensor 9 and the chip groove is far greater than that between the magnetic field sensor and the cutting edge area, so that the magnetic field intensity on a cutting edge line is greater than that of the chip groove area, and the magnetic field intensity transiting from the chip groove to the cutting edge has sudden change. The magnetic field sensor 9 records the intensity B' of the magnetic field at the position of the magnetic field sudden change, the corresponding coil number i is the corresponding height z, and the angular displacement sensor records the rotating angle theta of the worm wheel. Finally, the position (theta, z) at which each magnetic field strength is abruptly changed to B' (actual cutting edge) is acquired, and the data is transmitted into a signal processing system.

The structure of the signal processing system is shown in fig. 4, the output ends of the magnetic field sensor 9 and the angular displacement sensor 12 are connected with the input end of the preamplifier circuit, the output end of the preamplifier circuit is connected with the input end of the signal conditioning circuit, the output end of the signal conditioning circuit is connected with the input end of the signal processing circuit, and the output end of the signal processing circuit is connected with the input end of the display control circuit. When the cutting edge angle control device works, the magnetic field sensor 9 and the angular displacement sensor 12 convert a magnetic field signal B, a height z corresponding to a magnetic field and a corner signal theta into electric signals to be output, the electric signals are input into a preamplification circuit to be amplified due to the fact that the electric signals are weak, the amplified electric signals are input into a signal conditioning circuit to be subjected to noise reduction and analog-to-digital conversion and are converted into signals capable of being recognized by a signal processing circuit, the signal processing circuit processes and reconstructs the obtained cutting edge position information in a cylindrical coordinate system, and finally the cutting edge position information is displayed through a display control circuit.

When the end mill is worn, the shape of the cutting edge will change, affecting the magnetic field strength B at each position on the edge line. The process of collecting the distribution of the magnetic field strength of the unworn cutter is repeated for the worn end mill, the position (r, theta, z) where the magnetic field strength on each generatrix is suddenly changed to be B' is collected, and the points are input into a signal processing system to reconstruct the wear boundary of the flank face, as shown in FIG. 5. The magnitude of the wear amount of the end mill is determined by comparing the position of the cutting edge of the tool with that of the tool which is not worn.