Patent Application
20080210649
The invention relates to CNC (Computer Numerical Control) machining and in particular to a system for storing tool holders for use in CNC machining.
A CNC milling machine can make complex parts under computer control. Such machines may use a wide range of different milling cutters and other tools. For example, different milling cutters may be used for different materials or for roughing and finishing operations, and different tools may be used for different operations such as making slots, drilling holes, deburring, contouring and the like.
A typical CNC milling machine has an automatic tool changer that can accommodate up to some maximum number of tools. Each tool is fixed in a holder that can be held by the tool changer and removably attached to the spindle of the milling machine. Ideally, all of the tools required for the current job are held in the tool changer so that the job can be completed without changing the tools in the machine.
Where a machine shop makes production quantities of a range of various parts it is common to make those parts in batches. Setting up to make a particular part involves making sure that the correct tools are in the machine's tool changer and loading a program into the machine for making the part. Where the shop makes a significant range of parts, it is not practical to keep all of the tools required for making all of the parts in the machine's tool changer because the total number of tools is often more than the capacity of the tool changer. Consequently, there is a need for a way to store tools off of the machine. Machine shops that are set up to make a wide range of different parts may have a very large number of tools and tool holders in storage at any time.
Various tool storage systems exist. For example, it is typical to provide a rack cabinet or cart having a number of flat generally-horizontal shelves. The shelves have holes in them that are dimensioned to receive tool holders. These tool storage systems have various disadvantages including the difficulty of identifying and retrieving tools that are at the back of a shelf.
A program for a CNC milling machine typically expects that the working end of a specific tool will be at a specific distance from a datum on the tool holder. A presetter may be used to set a tool to project from a tool holder by a desired distance. It is periodically necessary to remove tools from tool holders for sharpening or replacement. After a tool has been replaced in a tool holder a tool presetter may be used to measure the amount that the tool projects from the tool holder. Presetters are available from various manufacturers. It is desirable to have a presetter conveniently at hand so that a machine operator can prepare tools for a job in an efficient manner.
Different milling machines accept tool holders having different tapers. “30” taper, “40” taper and “50” taper machines exist, among others. Tool holders for CNC machines typically have retention studs (also called “pull studs” or “retention knobs”) on their ends. The retention studs are used to hold the tool holders in the spindle or tool holder of the machine.
There is a need for improved tool storage systems. There is a particular need for such systems that have one or more of the following advantages: cost-effective; store a large number of tool holders and tools in a small amount of floor space; and, permit tools and tool holders to be readily identified and accessed.
The appended drawings illustrate non-limiting embodiments of the invention.
Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.
Each panel supports a plurality of tool storage receptacles 18. In the embodiment of
Receptacles 18 are generally horizontal (e.g. within ±15 degrees or ±20 degrees of horizontal). In the illustrated embodiment, each receptacle 18 extends generally at right angles to the panel 14 that supports it although this is not mandatory. In the illustrated embodiment, an imaginary centerline of each receptacle is inclined at a few degrees to the horizontal such that the centerline rises as one moves toward the front of the receptacle and falls as one moves toward the rear of the receptacle (i.e. the receptacles are tilted upwardly). In an example embodiment, each receptacle 18 is inclined to hold tool holders at an angle of about 6 degrees to the horizontal (i.e. an angle of about +6 degrees). In the illustrated embodiment, the receptacles are oriented to hold tool holders so that the tool holders are inclined upwardly (i.e. with the retention stud end of the tool holder lower than the tool-holding end of the tool holder).
Each receptacle can receive a tool holder. A large number of tools may be stored in tool holders in a fairly small area. Each of the tools is easily visible. System 10 has security bars 20 that prevent people from walking into exposed tools and also protect the tools from damage.
As shown in
Retention portion 26 has an opening 40 that is large enough to pass the head 32A of retention stud 32 below a slot 42 that is too small to pass head 32A of retention stud 32 but is large enough to receive the neck 32B of retention stud 32. Thus, a tool holder 30 may be securely engaged with receptacle 18 by pushing tool holder 30 into socket portion 24 until head 32A of retention stud 32 projects through opening 40 and then allowing tool holder 30 to pivot downwardly until neck 32B is received in slot 42, as shown in
In this engaged embodiment, resilient band 28 supports the tapered part 31 of tool holder 30 from below and retention stud 32 is urged upwardly into slot 42 because the center of gravity of tool holder 30 (together with any tool being held in tool holder 30) is outside of resilient band 28. In this embodiment, resilient band 28 acts as a fulcrum. In the illustrated embodiment, when tool holder 30 is engaged in receptacle 18 the centerline of tool holder 30 is not aligned with the centerline of socket portion 24. It is not necessary for socket portion 24 to have a shape that fits (i.e. that has the same taper as) tapered part 31.
Receptacles 18 may be dimensioned to accept tool holders of various different configurations and sizes. For example, in some embodiments, receptacles 18 are dimensioned to receive and retain 30-, 40-, 45-, 50- or 60-taper V-flange tool shanks.
The system 10A shown in
As shown in
It can be appreciated that the illustrated embodiments have the advantages of:
In the illustrated embodiment, aperture 63 is keyhole-shaped and has a larger-diameter portion 63A through which head 32A of retention stud 32 can pass and a smaller-diameter portion 63B which is too narrow to allow passage of head 32A but is wide enough to accept neck 32B. This can be seen in
Body 61 may be provided in various sizes. For example, different bodies 61 may be provided to accommodate 30-, 40-, 45-, 50- or 60-taper tool holders. In the illustrated embodiment, body 61 has a resilient band 65, such as an O-ring, in its bore. Band 65 protects the taper of a tool holder retained in receptacle 60.
A range of different styles and sizes of retention studs are used by different machine tool manufacturers. Different plates 62 may be provided to receive different designs of retention studs. The design of receptacle 60 provides flexibility. A receptacle 60 for receiving a particular taper of tool holder equipped with a particular size and style of retention stud can be provided by attaching a body 61 appropriate for the tool holder taper to a plate 62 which is configured to receive and hold the retention stud.
A tool holder 30 may be inserted into a receptacle 60 for storage by pushing the end of the tool holder 30 into the bore 67 of body 61 until the head 32A of retention stud 32 has passed through aperture 63 as shown in
In some embodiments, plate 62 is common to a plurality of receptacles 60. In some embodiments, plate 62 comprises an array of apertures 63 for receiving retention studs 32. In such embodiments, a user may attach bodies 61 to plate 62 adjacent to some or all of the array of apertures 63.
In the illustrated embodiment bodies 61 are attached to plate 62 by means of bolts or screws 66 that pass through apertures in plate 62 into threaded engagement with bodies 61. In alternative embodiments, bodies 61 are affixed to plate 62 by other affixation means such as:
In some embodiments, a plurality of receptacles 60 are arranged to provide a tool storage system wherein receptacles 60 in different regions of the tool storage system have plates 62 adapted to receive and secure different styles and/or sizes of retention studs. Thus, tool holders for one machine tool or group of machine tools may be stored in one region of the tool storage system while tool holders for other machine tools are stored in other regions of the tool storage system. In some embodiments, bodies 61 or plates 62 or receptacles 18 are color coded to identify the different regions of the tool storage system.
Computer 73 contains information relating to tools associated with receptacles 75. This information can be made readily available to machinists on the shop floor by way of display 74. For example, without limitation, computer 73 may contain information such as:
In an embodiment, computer 73 presents a graphical user interface (GUI) 80 of a particular kind as illustrated in
In some embodiments, including the illustrated embodiment, additional icons or other indicia may be associated with some controls 84. In the illustrated embodiment, some tool holders are ‘blocked’. Controls 84 for blocked tool holders are indicated by a fourth icon or other indicia. A tool holder may be marked as being blocked if that a tool holder is unavailable for use for some reason. For example, a user may set a tool holder to a blocked state in computer 73 if that tool holder is broken, unusable, out for repair or the like.
In the illustrated embodiment, computer system 73 has inadequate information for some tool holders. Certain information such as the length, diameter or the like of a tool held by a tool holder may be considered essential. Until all of the essential information has been provided to computer system 73 the compute system 73 may display an icon for the corresponding control 84 that indicates that no or incomplete information for the tool holder/tool is in computer system 73.
Computer 73 comprises an input device that a user may use to activate controls 84 and to otherwise control operations of computer 73. The input device may comprise a mouse, trackball, digital pen, touch pad, or the like. In preferred embodiments, display 74 comprises a touch screen. In such embodiments a user can activate a control 84 by touching a location on display 74 at which an icon representing a desired control 84 is being displayed.
A user may use computer 73 to obtain information about tools in tool storage system 72. For example, in an embodiment, the user finds the tool of interest in tool storage system 72 and locates the control 84 corresponding to the receptacle 75 in which the tool of interest is located. The user activates the control by touching display 74 at the location of the control 84. In response, computer may display information about the tool. The information may include some or all of the information described above, for example. In some embodiment, activating a control 84 causes computer 73 to display only selected parts of the information about the tool that is available in computer 73. In such embodiments, computer 73 may display a menu or the like that allows a user to select additional categories of information regarding the tool to be displayed.
In embodiments, computer 73 permits a user to search for tools having particular configuration. for example, computer 73 may permit a user to search for tools:
Computer 73 may be interfaced to a tool presetter by way of a suitable data communication path. This can enable information about tool length and diameter for a particular tool, as measured by the presetter, to be directly loaded into computer 73. In some embodiments, this also permits a particular tool to be identified.
For example, a tool presetter 77 is shown in
Each tool holder/tool combination may be labelled with indicia identifying the receptacle 75 of tool storage system 72 with which the tool/tool holder is associated. The indicia may, for example, be marked on labels attached to the tool holders, marked directly on the tool holders, engraved or etched into the tool holders, or the like.
Computer 73 may provide a tool-identification function. In a case where a label affixed to a tool holder has come off or become unreadable the tool identification function may be used to identify the tool based on information about the tool. For example, the offset of the tool may be measured. The tool identification function may search data maintained by computer 73 to locate any records associated with tools having the measured offset. In some embodiments the offset may be measured by presetter 77 and the measured value may be transmitted directly to computer 73 and provided as a search term for the tool identification function.
Computer 73 may track the current locations of tools that are not in tool storage system 72. In some embodiments, computer 73 comprises a function for coordinating the transfer or one or more tools from tool storage system 72 to a machine and/or coordinating the transfer of one or more tools from a machine back to assigned receptacles of tool storage system 72. In some embodiments the tool transfer function records the particular tool pocket in a machine (e.g. a local ID in the machine) to which a tool has been transferred. In such embodiments, computer 73 may maintain for each machine what tool is in each tool pocket of the machine (and which tool pockets are empty) as well as records of which tools are assigned to each receptacle 75 of tool storage system 72, which receptacles 75 do not have an assigned tool, and which tools that are assigned to a receptacle 75 are (or should be) present in the assigned receptacle 75.
In some embodiments, computer 73 applies tool placement rules to determine in which pocket in a machine certain tools ought to be loaded. For example:
In some embodiments, computer 73 is in data communication with a controller of a CNC machine 79. For example,
In some embodiments, additional information about tools present in a CNC machine is uploaded from computer system 73 to CNC machine 79. The additional information may comprise, for example, speeds or feeds or other operating parameters for the tools. The additional information may be stored as parameters in a controller of the CNC machine 79 so that the additional information is available to programs that are run on the controller of the CNC machine 79.
In some embodiments, computer 73 maintains information relating to machining jobs to be performed by CNC machines 79. The information may include, for example, lists of tools required for specific jobs and/or CNC programs to be run on CNC machines 79 in order to perform machining as required by the specific jobs. In some such embodiments, computer 73 executes a function that causes it to compare a list tools required for a job to the tools recorded as being present on a machine 79 which will be used in the job. Computer 73 then prompts a user to transfer any required tools not present in the machine 79 from tool storage system 72 to the machine 79. Computer 73 may specify which open tool pockets of the machine 79 the tools will be inserted into or, in the alternative, may allow a user to select an arrangement for the tools in the tool pockets and input into computer 73 which tool is in which pocket of the machine 79.
A CNC machine typically has a tool changer. The controller of the machine can cause the tool changer to transfer a tool that is currently in a spindle of the machine or otherwise ready for use into a pocket and to load a new tool from another pocket. Tool changes are typically specified by a program that controls the machine. The program typically requests tools by an ID (pocket) for the tool. In cases where a tool is always returned to the same location in a magazine then the ID may be an ID associated with that magazine location. Some CNC machines have ‘random’ tool storage. In such machines a tool may not be returned to an original magazine location when it is changed out. In such machines the machine controller assigns an ID to each tool and keeps track of the magazine locations in which different tools are stored. In such machines the program can request tools by tool ID.
In some embodiments, computer 73 has a function for uploading programs to CNC machines 79. In some such embodiments, the programs stored in computer 73 reference different tools that they require using placeholder information that identifies directly or indirectly the receptacles in tool storage system 72 corresponding to the required tools. In such embodiments, before uploading a program to a CNC machine 79 computer 73 identifies the local ID (e.g. pocket) in which each of the required tools is stored on the CNC machine 79. Computer 73 then modifies the program by substituting for the placeholder information in the program the corresponding local ID in the CNC machine 79 for each tool to be used by the program. Computer 73 can then upload the modified program to the CNC machine 79. This may be done automatically or with user input or assistance.
In some embodiments, a program stored in computer system 73 may have placeholders for or references to information other than tool locations. An example of such other information is speeds or feeds for certain tools. In some such embodiments, computer system 73 modifies the program with information for the selected tools. This information may be retrieved from a data store accessible to computer system 73. The program modifications could be performed, for example, by replacing the placeholders with corresponding information for the selected tools or by supplying information to be stored at locations identified by the references.
As an example application consider the case where a tool holder initially holds a ½-inch diameter end mill of a type for which the recommended speed in a material for the job is 2000 RPM. In this case, when the program, as modified by computer 73 is run on the CNC machine 79 the program will cause the CNC machine 79 to operate the tool at 2000 RPM. If the tool is replaced with a high-performance endmill that can be operated at a speed of 10,000 RPM in the material for the job and the data in computer 73 is updated to specify 10,000 RPM as the speed for the tool then the next time the program is uploaded to the CNC machine 79 computer system 73 will modify the program such that the CNC machine 79 will operate the tool at 10,000 RPM. This can be achieved without requiring any human operator to manually edit the program at the CNC machine or elsewhere.
In some embodiments, the programs uploaded by computer 73 include G-code, which may be based upon the RS-274D standard originally developed by the Electronic Industry Association. In such programs, tools may be selected by a T-word. For example, in such programs T10 would cause the tool changer of a CNC machine 79 to select the tool having ID “10”.
Computer 73 may provide additional useful functions. For example, computer 73 may monitor the amount of time taken by various jobs, the jobs run by different machine shop personnel, the cost of tooling expended on a job, etc.
In an example embodiment, a user wishes to run a job on a particular CNC machine 79. The user selects the job on an interface provided by computer 73. This may be done by touching a touch-sensitive display 74. Computer 73 determines what tools are required for the job and determines which, if any of those tools are already present in the selected CNC machine 79. Computer 73 generates a set of transfer instructions which, when performed by a machine operator will result in the selected machine 79 having the tools required for the selected job. The transfer instructions instruct the operator to transfer tools from tool storage system 72 to the selected machine 79 and/or from the machine 79 to tool storage system 72. An example of a transfer instruction is “Transfer the tool at location #45 on the tool storage system to pocket #7 on machine #1.”
The machine operator confirms completion of each transfer instruction by, for example, touching a control on display 74. Computer 73 updates its internal records regarding the location of each tool. In this example, computer 73 then uploads offset information for each tool to the controller of the selected machine 79. Computer 73 also uploads a program for the selected job to the controller of machine 79. In uploading the program, computer 73 replaces placeholder references to tools with references to the local ID (e.g. pocket number) of each referenced tool in the selected machine 79. The operator can then run the job on the selected machine 79. Computer 73 tracks statistics regarding the job (for example, the time taken to run the job etc.).
In some workplaces there are CNC machines that accept different types of tool holders. For example, the workplace may have some CNC machines that accept one taper of tool holder and other machines that accept another taper (e.g. some machines may be 50-taper machines and other may be 30-taper machines). As another example, some machines may require one geometry of retention stud while other machines may require another geometry of retention stud. In these cases, tool holders are not interchangeable between machines of the different groups. In such cases, a separate tool storage system 72 or a separate section of a tool storage system 72 may be assigned to each group of machines. Computer 73 may be configured to separately perform the functions as described herein for each of two or more groups of non-compatible tool holders. This permits a single computer system 73 to be used to manage tools for multiple different groups of CNC machines.
Certain implementations of the invention comprise data processors which execute software instructions which cause the processors to perform a method of the invention. For example, one or more processors in a computer 73 may implement methods as described herein executing software instructions in a program memory accessible to the processors. Computer 73 need not be a general-purpose computer. The functions of computer 73 could be provided by a suitable embedded processor in a system customized to perform functions of the nature described herein. The invention may also be provided in the form of a program product. The program product may comprise any medium which carries a set of computer-readable instructions which, when executed by a data processor, cause the data processor to execute a method of the invention. Program products according to the invention may be in any of a wide variety of forms. The program product may comprise, for example, physical media such as magnetic data storage media including floppy diskettes, hard disk drives, optical data storage media including CD ROMs, DVDs, electronic data storage media including ROMs, flash RAM, or the like. The computer-readable instructions on the program product may optionally be compressed or encrypted.
Where a component (e.g. a panel, frame, receptacle, slot, member, device, display, computer, etc.) is referred to above, unless otherwise indicated, reference to that component (including a reference to a “means”) should be interpreted as including as equivalents of that component any component which performs the function of the described component (i.e., that is functionally equivalent), including components which are not structurally equivalent to the disclosed structure but which perform the function in the illustrated exemplary embodiments of the invention.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. For example:
This application claims the benefit of U.S. Provisional Application Ser. No. 60/886,717 filed 26 Jan. 2007 and entitled STORAGE SYSTEM FOR TOOL HOLDERS which is hereby incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60886717 | Jan 2007 | US |
