Automatic tool layout apparatus and method

1. Field of the Invention

The present invention relates to tool layout apparatuses and methods, and particularly to an automatic tool layout apparatus and method used in a computer-aided manufacturing system for sheet-metal punching.

2. Background of the Invention

With the ongoing globalization of commerce, market competition between modern international corporations is becoming more and more intense. All such manufacturing corporations have to try their best to improve their competitiveness. Improving production efficiency is a never-ending challenge. Improvements in machine punching tool hardware and falling commodity prices have helped increase many corporations' efficiency. Further, the use of computers to automate manufacturing has become popular, and has improved the speed and quality of sheet-metal punching. Sheet-metal punching at the present time mostly uses CAD (Computer Aided Design) to form 3-dimension models and define workpieces, and CAM (Computer Aided Manufacturing) to select an optimum manufacturing path for a punching tool.

There are two notable problems with automated sheet-metal punching at the present time: only experienced technicians are able to select an optimum punching tool for each type of drawing entity of workpieces, and to select an optimum manufacturing path for the punching tool; and database accessing is numerous and time-consuming when configuring a layout of the punching tools.

There is a need for an apparatus and method which can overcome the abovementioned problems of high labor intensity, human error, and limited production efficiency.

Accordingly, a main objective of the present invention is to provide an automatic tool layout apparatus and method, in which the automatic tool layout apparatus can receive drawings from client computers to obtain information on workpieces, select punching tools and corresponding tool stations for the punching tools, mount the punching tools in the corresponding tool stations, select an optimum manufacturing path for each of the punching tools, and record tool layout information.

To accomplish the above objective, an automatic tool layout apparatus (hereinafter “the apparatus”) used in a computer-aided manufacturing system for sheet-metal punching (hereinafter “the system”) is provided herein. The system includes a plurality of client computers, a database, and a server. The database stores information such as drawings from the client computers, punching tool information, turret information, tool layout information, and materials of workpieces and machining allowances set by users. The client computers can access the server via networks to view related tool layout information timely. The automatic tool layout apparatus resides in the server, and includes a drawing processing module, a condition maintaining module, a matching module, a searching module and a tool layout module.

The drawing processing module is used for receiving drawings from the client computers, obtaining information on workpieces from the drawings, and storing the drawings in the database. The condition maintaining module is used for calculating exact conditions and inexact conditions for each type of drawing entity of the workpieces. The matching module is used for examining whether any punching tool on a turret matches with at least one type of drawing entity according to the calculated exact conditions or inexact conditions of the type of drawing entity, and selecting the punching tool if it matches with the exact conditions or inexact conditions of at least one type of drawing entity. The searching module is used for searching the database for corresponding punching tool information if no punching tool on the turret matches with any one particular type of drawing entity. The tool layout module is used for selecting corresponding tool stations for selected punching tools according to a type of the turret and the specifications of the selected punching tools, mounting the selected punching tools in the corresponding tool stations, selecting an optimum manufacturing path (a machining sequence of a punching tool) for each of the selected punching tools, and recording tool layout information.

Further, the present invention provides an automatic tool layout method comprising the steps of: (a) receiving drawings from client computers to obtain information on workpieces; (b) selecting punching tools according to sizes and shapes of each type of drawing entity of the workpieces and according to materials of the workpieces and machining allowances set by users; (c) selecting corresponding tool stations according to a type of a corresponding turret and specifications of the selected punching tools, mounting the punching tools in the corresponding tool stations, and selecting an optimum manufacturing path for each of the punching tools; and (d) recording tool layout information.

Other objects, advantages and novel features of the present invention will be drawn from the following detailed description with reference to the attached drawings, in which:

FIG. 1 is a schematic diagram of an application environment of an automatic tool layout apparatus according to the present invention;

FIG. 2 is a schematic diagram of main function modules of the automatic tool layout apparatus of FIG. 1 ;

FIG. 3 is a flowchart of a preferred method for implementing the automatic tool layout apparatus; and

FIG. 4 is a flowchart of a preferred method for implementing one of steps of FIG. 3 , namely selecting a punching tool for a type of drawing entity.

FIG. 1 is a schematic diagram of an application environment of an automatic tool layout apparatus 2 (hereinafter “the apparatus”) used in a computer-aided manufacturing system for sheet-metal punching (hereinafter “the system”) according to the present invention. The system comprises a plurality of distributed client computers 7 , a database 3 , and a server 1 . The client computers 7 are connected to the server 1 via a network 4 , in order to obtain relevant tool layout information and to view the tool layout information timely. The network 4 may be any suitable communication architecture required by the system, such as a local area network or a wide area network. The server 1 is connected to the database 3 via a connection 6 . The connection 6 is a database connectivity such as an Open Database Connectivity (ODBC) or a Java Database Connectivity (JDBC). The database 3 stores information such as drawings received from the client computers 7 , punching tool information, turret information, tool layout information, materials of workpieces, and machining allowances set by users. The punching tool information includes specifications, types and parameters of punching tools. The turret information includes a type of each turret, and a size and location of each of tool stations an the turrets. The tool layout information includes locations of punching tools on each turret, and an optimum manufacturing path of each punching tool (a machining sequence of the punching tool). The automatic tool layout apparatus 2 resides in the server 1 , and is used for: receiving drawings from the client computers 7 to obtain information on workpieces; selecting punching tools in accordance with sizes and shapes of each type of drawing entity of the workpieces and in accordance with materials and machining allowances set by users; selecting a corresponding tool station for each punching tool in accordance with a type of a turret and the punching tools specifications; mounting the punching tools in the corresponding tool stations; selecting an optimum manufacturing path for each punching tool; and recording tool layout information.

FIG. 2 is a schematic diagram of main function modules of the automatic tool layout apparatus 2 . The automatic tool layout apparatus 2 includes a drawing processing module 10 , a condition maintaining module 20 , a matching module 30 , a searching module 40 , and a tool layout module 50 . The drawing processing module 10 is used for receiving drawings from the client computers 7 via the network 4 , obtaining information on workpieces from the drawings, and storing the drawings in the database 3 . The condition maintaining module 20 is used for calculating exact conditions and inexact conditions for each type of drawing entity of the workpieces. The exact conditions are calculated according to shapes and sizes of the type of drawing entity. The inexact conditions are calculated according to materials of the workpieces and machining allowances set by users. The exact conditions calculated for each type of drawing entity comprise a radius, an including angle and an apex of the type of drawing entity. The inexact conditions calculated for each type of drawing entity comprise a rotational angle and a rotational direction of the type of drawing entity. The matching module 30 is used for examining whether any punching tool on a turret matches with at least one type of drawing entity according to the calculated exact conditions or inexact conditions of the type of drawing entity, and selecting the punching tool if it matches with the exact conditions or inexact conditions of at least one type of drawing entity. The searching module 40 is used far searching in the database 3 for corresponding punching tool information if no punching tool on the turret matches with any one particular type of drawing entity. The tool layout module 50 is used for selecting a corresponding tool station on the turret for each selected punching tool according to the type of the turret and the selected punching tool's specifications, mounting the punching tool in the corresponding tool station, selecting an optimum manufacturing path (a machining sequence of the punching tool) for the selected punching tool, and recording tool layout information.

FIG. 3 is a flowchart of a preferred method for implementing the automatic tool layout apparatus 2 . In step S 301 , the drawing processing module 10 receives a drawing from a client computer 7 , and obtains information on workpieces from the drawing. In step S 302 , the automatic tool layout apparatus 2 selects a punching tool for each type of drawing entity according to sizes and shapes of the type of drawing entity and according to materials of the workpieces and machining allowances set by users. (The procedure of selecting a punching tool for a type of drawing entity is described in detail below in relation to FIG. 4 .) In step S 303 , the tool layout module 50 selects a corresponding tool station for each selected punching tool according to the type of a corresponding turret and specifications of the selected punching tool, mounts the selected punching tools in the corresponding tool stations, and selects an optimum manufacturing path for each of the punching tools. In the preferred embodiment of the present invention, drawing entities of the same type are machined using the same punching tool. Selecting an optimum manufacturing path for each punching tool means selecting a machining sequence for drawing entities of each same type using the same punching tool. In step S 304 , the tool layout module 50 records the tool layout information.

FIG. 4 is a flowchart of a preferred method for implementing step S 302 of FIG. 3 , namely selecting a punching tool for a type of drawing entity according to sizes and shapes of the type of drawing entity and according to materials of the workpieces and machining allowances set by users. In step S 401 , the condition maintaining module 20 calculates exact conditions for the type of drawing entity according to the shapes and the sizes of the type of drawing entity, and calculates inexact conditions according to the materials of the workpieces and machining allowances set by users. In step S 402 , the matching module 30 examines whether a same type of drawing entity has been processed before. If the same type of drawing entity has been processed before, in step S 403 , the matching module 30 selects the punching tool, that was previously used to machine the same type of drawing entity. If the type of drawing entity has not been processed before, in step S 404 , the matching module 30 examines whether any punching tool on a corresponding turret matches with the exact conditions of the type of drawing entity. If any punching tool on the turret matches with the exact conditions of the type of drawing entity, the procedure goes directly to step S 410 described below. If no punching tool on the turret matches with the exact conditions of the type of drawing entity, in step S 405 , the searching module 40 searches in the database 3 for corresponding punching tool information that matches wit the exact conditions of the type of drawing entity. In step S 406 , the searching module 40 determines whether any corresponding punching tool exists according to searched punching tool information in the database 3 . If any corresponding punching tool exists, in step S 407 , the matching module 30 determines whether the punching tool can be mounted on the turret according to specifications of the punching tool, a type of the turret, and sizes of tool stations on the turret. If the punching tool can be mounted on the turret, the procedure goes directly to step S 410 described below. If no corresponding punching tool exists according to searched punching tool information in the database 3 , or if the punching tool cannot be mounted on the turret, in step S 408 , the matching module 30 examines whether any punching tool on the turret matches with the inexact conditions of the type of drawing entity. If any punching tool on the turret matches with the inexact conditions of the type of drawing entity, the procedure goes to step S 410 described below. If no punching tool on the turret matches with the inexact conditions of the type of drawing entity, in step S 409 , the searching module 40 searches in the database 3 for corresponding punching tool information that matches with the inexact conditions of the type of drawing entity, whereupon the procedure returns to step S 406 described above. In step S 410 , the matching module 30 selects the punching tool.