AUTOMATIC SYSTEM FOR CUTTING TOOL INSPECTION AND REPLACEMENT

Abstract

A method and an automatic system for evaluating the condition of a cutting tool insert in a machine tool comprising an inspection device and a processing software for tool wear evaluation. Such system comprises means for manipulating the cutting tool insert(s), replacing it/them when worn or broken, based on the assessment provided by the post processing software or based on user defined settings.

Claims

1. An automatic system for detecting a wear condition of cutting tool inserts of a machine tool, each cutting tool insert being housed in a respective tool body of a tool holder in a machine tool magazine or in a confined space adapted to safely handle said tool holder, wherein the system comprises: manipulating means able to pick up from said machine tool magazine or from said confined space one of said tool holders housing the cutting tool insert/s to be subjected to wear inspection; a support detached from the machine tool able to stably holding said picked up tool holder; an inspection device able to detect the wear condition data related to said cutting tool insert/s housed in the picked up tool holder; a data management platform able to collect said detected wear condition data for each of said inspected cutting tool inserts; a control unit able to (i) evaluate the effective wear condition of said cutting tool insert either directly or by comparing said detected wear condition data with a pre-established set of tool wear condition data; and means to a) eventually remove from the tool holder an integral cutting tool insert detected as worn by the wear inspection and to replace it with a new one, or to b) eventually remove from the tool holder an individual cutting tool insert detected by the wear inspection as having at least one not-worn cutting face and to eventually reposition it in said tool body of the tool holder so that said not-worn cutting face of the individual cutting tool insert is repositioned in an effective operative position.

2. The automatic system as set forth in claim 1 wherein said manipulating means comprise a robot provided with a wrist eventually bearing removable end-effectors, such as a gripper able to grab said tool holder while it is removed from said machine tool magazine or from said confined space and positioned onto the support, or such as a brush-like device, or other solid, liquid and gaseous means able to remove dirt and other impurities from the surface of the cutting tool insert to be subjected to inspection.

3. The automatic system as set forth in claim 1 wherein said inspection device is a camera, a laser scanner, a microscope, or similar devices, or any combination of such devices.

4. The automatic system as set forth in claim 1 wherein said support for stably holding the picked-up tool holder is a rotating table.

5. The automatic system as set forth in claim 2 wherein said robot is able to move said inspection device around said tool holders housing the cutting tool insert to be subjected to wear inspection.

6. The automatic system as set forth in claim 1 wherein said cutting tool insert to be subjected to wear inspection housed in the tool body of the tool holders is an individual cutting tool insert provided with a plurality of cutting faces whose wear condition are detected independently one from each other.

7. The automatic system as set forth in claim 1 wherein said cutting tool insert to be subjected to wear inspection housed in the tool holder is an integral cutting tool insert, which is fastened on the tool holder.

8. The automatic system as set forth in claim 7 which further comprises means for calculating an offset for the correct utilization of the new integral cutting tool insert which replace the worn one.

9. The automatic system as set forth in claim 1 which further contains collecting means for collecting any replaced worn cutting tool insert.

10. The automatic system as set forth in claim 1 which further contains a cutting tool insert container housing not yet used spare cutting tool inserts to be used to replace said worn detected cutting tool inserts.

11. The automatic system as set forth in claim 1 wherein said pre-established set of tool wear condition data is able to be updated each time at least one of said worn cutting tool insert has been replaced by a new one.

12. The automatic system as set forth in claim 1 which further contains a graphical user interface able to show data related to the cutting tool insert wear evaluation, to the tool useful life statistics, and/or suggesting optimal tool replacement strategies.

13. A method for automatically inspecting a wear condition of at least a cutting tool insert housed in a tool body of a tool holder of a machine tool, wherein for each cutting tool insert to be wear inspected the method comprises: a) picking up, or receiving from a machine tool magazine or from a confined space adapted to safely handle said tool holder, the tool holder housing the cutting tool insert to be inspected and transferring it to a detached support for stably holding the tool holder during the cutting tool insert wear inspection; b) cleaning the cutting tool insert held in the corresponding tool holder housing it; c) detecting the wear condition data of said cutting tool insert; d) collecting said wear condition data of the inspected cutting tool insert on a data management platform; e) comparing said detected cutting tool insert wear condition data with a pre-established set of cutting tool insert wear condition data in order to establish its wear condition; f) eventually removing from the tool holder a) the integral cutting tool insert detected by the wear inspection as completely worn and replacing it with a not-worn one, or b) the individual cutting tool insert which has at least one not-worn cutting face and eventually repositioning it in the tool body of the tool holder in such a way that said not-worn cutting face of the individual cutting tool insert is re-positioned in an effective operative position.

14. The method as set forth in claim 13 which further comprises identifying said tool holder housing the cutting tool insert before the wear inspection starts.

15. The method as set forth in claim 13 wherein, when said individual cutting tool insert comprises a plurality of cutting faces, said detecting relates to detect the wear condition of each of said plurality of cutting faces.

16. The method as set forth in claim 13 wherein, when said cutting tool insert consists of an integral cutting tool insert that results to be worn after being subjected to said wear inspection, the entire integral cutting tool insert is discarded and replaced by a new one.

17. The method as set forth in claim 13 which further comprises statistically analyzing the data collected during the wear inspection of said cutting tool inserts in order to extend the knowledge of a machining process and provide further optimization.

18. The method as set forth in claim 13 which further comprises interfacing to other company systems, such as ERP or process monitoring systems, to provide suggestions for improving/adapting the estimation of an effective tool life of the cutting tool inserts.

19. The method as set forth in claim 13 which further comprises monitoring stability of a cutting process in the machine tool.

20. The method as set forth in claim 13 where tool wear inspection and tool inserts replacement are performed while the tool holder is still clamped on a machine tool spindle.

Description

[0104] Further characteristics and advantages of the present invention will be better highlighted by examining the following detailed description of a preferred but not exclusive embodiment, illustrated by way of non-limiting examples, with the support of the attached drawings, in which:

[0105] FIG. 1 schematically shows a tool holder being placed onto a rotary table for wear inspecting the cutting tool insert(s) housed in the tool holder;

[0106] FIG. 2 shows a robot provided with an end-effector with an insert cleaning brush;

[0107] FIG. 3 shows the cutting tool insert shown in FIG. 2 subjected to wear inspection by a camera;

[0108] FIG. 4 shows an individual cutting tool insert with three inserts, each of them having four cutting faces;

[0109] FIG. 5 shows an integral cutting tool element with four cutting faces.

DETAILED DESCRIPTION OF THE INVENTION

[0110] The following detailed description refers to particular embodiments of the cutting tool insert inspection/replacement system and related method of the present invention shown in FIGS. from 1 to 5, without limiting its content.

[0111] With particular reference to FIGS. from 1 to 4 a first embodiment of the system comprises a rotating table 12 able to stably hold a picked-up tool holder 3 bearing individual cutting tool inserts 6 during a wear inspection. The system further comprises a robot 14 provided with a wrist 13 to which a gripper 11 for holding the tool holder 3 and for positioning it onto the rotating table 12 has been fixed. A camera 10 is fixed to the robot 14 through a support arm 16; the camera 10 is used as an inspection device to detect the wear condition of the individual cutting tool insert 6.

[0112] FIG. 2 shows the same system of FIG. 1 wherein the wrist 13 is equipped with a brush-like end-effector 15 (rather than the gripper 11 shown in FIG. 1) able to remove dirt and other impurities from the surface of the individual cutting tool insert 6 before subjecting it to wear inspection, while FIG. 3 shows the same system of FIG. 1 wherein all end-effectors are removed from the wrist 13 of the robot 14 in order to render easier the wear inspection accomplished by the camera 10.

[0113] The tool holder 3 bearing the individual cutting tool insert 6 is shown in detail in FIG. 4, wherein the tool holder includes the shank 1, which is fixed to the rotating table 12 through the lower protuberance 17, and the flange 2, which is used for handling the tool holder 3. Furthermore, the tool body 4 allows the tool holder 3 to bear the individual cutting tool insert 6. In FIG. 4 three individual cutting tool inserts 6 are shown, each of them has four cutting faces 5 and a fixing screw 7.

[0114] Operatively, the wear inspection procedure of the individual cutting tool insert 6 starts by the numerical control whenever the automatic system is installed close to the working area, in proximity of the machine tool or in the tool magazine. The numerical control communicates to the system several information including the individual cutting tool insert ID number and the position in the tool magazine. The individual cutting tool insert is identified by retrieving the tool number information from the machine numerical control, or directly via RFID, or by scanning with the camera 10 the tool's quick response code (QR), barcode, or serial number.

[0115] The tool holder 3 bearing the individual cutting tool insert 6 is picked from its position on the tool magazine of the machine tool by the gripper 11 fixed to the wrist 13 of the robot 14, as shown in FIG. 1. Then, the tool holder 3 is positioned onto the rotating table 12. The individual cutting tool insert 6 has to be cleaned, removing the unwanted material from the tool surface. To this end, the gripper 11 is removed from the wrist 13 of the robot 14 and replaced by the brush 15 as shown in FIG. 2. Once the individual cutting tool insert 6 is completely clean, the brush 15 is removed from the wrist 13 of the robot 14 and the wear inspection through the camera 10 starts.

[0116] The evaluation can be done by comparing the reference information of the individual cutting tool insert 6 (in the same position) with the current one, acquired via the inspection device or it may be done by a direct measurement of the wear. The reference information of the individual cutting tool insert 6 is the one acquired before the first use of the system or the first use of the individual cutting tool insert 6, when it is new. The presence of wear on the individual cutting tool insert 6 is detected by analyzing the differences between the reference picture(s) and the current one(s) taken by the camera 10.

[0117] The picture(s) or the features extracted from the picture(s) taken by the camera 10 during the analysis are saved in the data management platform for tracking updated information about the wear development process of the individual cutting tool insert 6.

[0118] The individual cutting tool insert 6 accumulated machining time is compared to the tool lifetime defined by the end user or available on the data management platform for that individual cutting tool insert 6. The lifetime of the individual cutting tool insert 6 is here intended as a predefined fixed value.

[0119] If the lifetime is already reached or will be reached in few machining cycles, the individual cutting tool insert 6 has to be changed; otherwise, the individual cutting tool insert 6 can be used again.

[0120] In case the individual cutting tool insert 6 is to be replaced, it must be removed from the tool body 4. This operation involves the unscrewing of the screw 7 which fixes the individual cutting tool insert 6 to the tool insert holder 3 in operating conditions. The screwdriver may be an electric or pneumatic screwdriver; the size of the screw is calculated based on the images of the camera 10 or retrieved from the tool information stored in the data management platform and an adequate screwdriver or screwdriver bit is selected for carrying out the unscrewing operation. The direction and the position of the screwdriver can be calculated by using the information gathered via the camera 10; this information can be advantageously stored in the data management platform when the reference information of the individual cutting tool insert 6 is acquired and used automatically in the following inspections for reducing the individual cutting tool insert 6 replacement time.

[0121] Then, the worn individual cutting tool insert 6 is picked up by means of a dedicated gripper (not shown) and positioned in a suitable collecting means for collecting any replaced worn individual cutting tool insert 6. A new individual cutting tool insert 6 of the same type of the discarded worn one, is picked up from a tool insert storage, housing a plurality of individual cutting tool inserts 6 by using the same gripper used for picking the worn individual cutting tool insert 6. The system can include information on the level of each tool insert storage, in order to communicate to the operator when to refill it with additional individual cutting tool inserts 6.

[0122] In the particular embodiment of the present invention shown in FIG. 4, the individual cutting tool insert 6 is of the indexable type, that means it is constituted by a plurality of cutting faces 5. In this case, the wear inspection procedure checks all the cutting faces 5 of the individual cutting tool insert 6, or data on tool faces status are retrieved from the data management platform. If all the cutting faces 5 are worn, then the indexable individual cutting tool insert 6 cannot be used anymore and is to be replaced. If, on the contrary, at least one cutting face 5 is not worn, the automatic system re-orients the individual cutting tool insert 6 in such a configuration that the selected cutting face 5 can be used in the next machining operation.

[0123] This inspection and replacement process is repeated for all the individual cutting tool inserts 6 in the tool holder 3.

[0124] When the inspection/replacement process is over, a signal is sent to the numerical control of the machine or to the operator, confirming the availability of the tool for the next machining operation.

[0125] Once all the individual cutting tool inserts 6 are ready to be used again because new or not completely worn, all the necessary information retrieved in the process are stored in the data management platform and kept for further analyses. Once a sufficient amount of data on the wearing process of the individual cutting tool inserts 6 in a particular machining process is available, the system performs a statistical analysis and provides to the user some suggestions on how to optimize the usage and the replacement of the individual cutting tool inserts 6 in order to minimize costs, processing times or other key performance indicators defined by the user. This information is made available by the system to the user via a graphical user interface at the machine, but the same information can be made available also remotely via a dedicated app developed both for mobile devices and for PCs. The system can also issue and send periodic reports to the user.

[0126] With particular reference to FIG. 5 a second embodiment of tool holder 3 is shown; in this embodiment, the insert tool is an integral cutting tool insert 8, that means it is realized by a single block which is fastened on the tool holder 3, and bears four cutting faces 9.

[0127] When the integral cutting tool insert 8 is worn, the cutting faces 9 can be replaced only by replacing the whole integral cutting tool insert 8. In this case, since every time they are replaced their dimensions can vary with respect to those of a reference integral cutting tool insert 8, the method includes the phase to measure and calculate an offset during the replacement of the worn integral cutting tool insert 8. The measurement of the dimensions of the new integral cutting tool insert 8 is known as tool presetting and the difference between the reference values and the measured value is communicated to the numerical control of the machine before the integral cutting tool insert 8 is used in the next process.

[0128] Naturally, many modifications and variations of the described preferred embodiments will be evident to those skilled in the art, still remaining within the scope of the invention.

[0129] Therefore, the present invention is not limited to the preferred embodiments described, illustrated only by way of non-limiting example, but is defined by the following claims.