JPS6144619B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flexible loader device built into a machine tool for supplying and unloading objects such as workpieces and/or tools to chucks, tables, and turrets of machine tools, and a method for using the same. This is related to the improvement of In recent years, general conveyance robots have begun to be used to automate the supply of materials to machine tools and the unloading of workpieces to enable continuous machining operations. Unexamined Japanese Patent Publication 1987-
Publication No. 152552 has good workability and high safety.
However, the present invention proposes a flexible loader device that does not increase the required floor space and a method of using the flexible loader that allows the operation of the flexible loader to be easily changed within a short period of time. The present invention further improves this to provide accurate positioning by adjusting the amount of displacement of the flexible loader in response to weight differences between various types of transported objects, and also to perform accurate positioning by adjusting the displacement of the flexible loader in response to weight differences between various types of transported objects. Based on the transported object table containing the mounting type processing stored in the storage area of the control device, the This selects the transport/exchange or assembly operation of the conveyed object of the flexible loader device. In an NC lathe, when conveying, exchanging, or assembling conveyed objects such as tools or workpieces of different weights, a motion number, for example, is commanded to the flexible loader as a motion command. Generally, this command has different operation numbers depending on the weight of the conveyed object, but in the present invention, these are the same operation number to simplify the command given by the NC lathe programmer, and to make it easier for the NC lathe or flexible loader to This makes it easy for operators to teach the flexible loader. In addition, it is compatible with tools that change the operation number of the flexible loader when a control device such as an unmanned monitoring function monitors and judges automatic tool replacement in situations where the replacement tool cannot be specified in advance during unmanned operation. By providing this information, it is possible to automatically exchange tools during unmanned operation. In the following embodiments, tools will be described as objects to be transported, but of course the present invention can also be used for transporting and assembling other heavy objects such as drive devices. Another object of the present invention is to automatically generate, within a control device, a displacement correction amount of a robot gripping part in response to a difference in tool weight when a conveyance robot is used to change tools as an automatic tool change system in an NC lathe. This facilitates the setup and simplifies the operation program stored in the control device. Another object of the present invention is that by using it with a robot, it becomes easy to change the order of tool exchange operations, which allows fixed tools for turning (bits, etc.) and rotary tools for drilling and milling (drills, milling cutters, etc.) to be easily changed. ), it is possible to realize an automatic exchange device for tools with different clamp types, such as compound machining tools. Next, the present invention will be explained based on embodiments shown in the drawings. FIG. 1A is a side view schematically showing one operating state of a flexible loader (hereinafter referred to as robot), FIG. 1B is a perspective view of the robot, and FIG. 1A is a replacement tool 2 held by robot 1. The center position 2a of the tool rest 3 is the tool mounting center position 3a of the tool post 3.
Indicates positioning to match the height of
Figure 1B shows the control axes and control directions of each part of the robot in a state where no tool is gripped, where 1 is the robot, 1a is the robot arm, and 1b is the robot arm.
is a robot band, 1c is a robot claw, 1d is a robot body, and 1e is a wrist. Generally, the robot 11 has lower rigidity than a machine tool, and therefore, depending on the weight W of the replacement tool 2 held, _{the angles θ} Change. That is, Now _, if the relationship between _the angular _{displacements} △ _θ It can be seen that there is a proportional relationship with W. Note that this proportional relationship is unique depending on the mechanism such as the length of the arm 1a of the robot. Therefore, the tool mounting center position 3a of the tool rest 3 is set in advance.
Find the relationship between the weight W and _displacement (△ _θ
Tool weight storage area 1 in the control device, which will be described later in the figure.
Magazine number as shown in Table 1 below in 0B,
By preparing a table (tool table) of the tool weight W and the taught standard tool number, it becomes possible to automatically correct the correction amount by teaching for any tool.

[Table] Similarly, if we find the relationship between tool weight W and displacement (△θ′ _X and △θ′ _y ) at the tool magazine position, we can obtain
The amount of robot displacement at the tool magazine position when returning the tool can be corrected. The correction amount due to the difference in tool weight is corrected using the following formula. However, X _C and Y _C are the correction amounts corrected based on the weight difference, X _St and Y _St are the correction amounts of the standard tool, W _St is the weight of the standard tool, W is the weight of the tool held by the robot, and then Figures 3A and 3B show the robot 1, tool holder 5a, and tool magazine 4 at the program origin, that is, the robot start position (V ₀ , W ₀ , X ₀ , Z ₀ in the robot program below).
In the side view and front view showing the arrangement relationship of a, the first
As in the figure, 1 is a robot, 1a is a robot arm, 1
b is a robot hand, 1c is a robot claw, 1d is a robot body, 1e is a wrist, 3 is a tool rest, 4a
5a is a tool magazine, and 5a is a tool holder.
In addition, the commanded movement amount of the robot in the program example is per pulse. It is as follows. Figure 4 shows an example of dovetail groove connection for lathe tools,
The robot claw 1c pulls out the fixed turning tool 6a from the tool magazine 4a in the -Z direction, swings the robot arm 1a in the -Y direction, rotates the wrist 1e in the +Y direction, and rotates the robot hand 1b.
Rotate 90° in the +W direction, then turn robot 1 +
The tool holder 5a is lowered in the V direction to perform dovetail jointing with the tool holder 5a. When the machining with the tool 6a is completed, the fixed tool 6a is lifted out of the tool holder 5a in the -V direction again, and the robot arm 1a,
The wrist 1e and the robot 1b are each swung and rotated in the directions opposite to those described above, and then the robot 1 is moved to +
It is moved in the Z direction and attached to the tool magazine 4a. Fig. 5 shows an example of a taper connection in the shank part of a rotary drilling tool, in which the rotary drilling tool 6b is grasped from the tool magazine 4b by the robot claw 1c and raised in the -V direction, and the robot arm 1a is moved to the -X direction.
At the same time, the wrist 1e is rotated in the +Y direction, and the robot hand 1b is rotated 90 degrees in the -W direction, and then the robot 1 is moved in the +Z direction and fixed to the tool holder 5b. When the machining with the tool 6b is completed, the robot claw 1c is used again to remove the tool 6.
b and pull it out in the -Z direction, swing and rotate the robot arm 1a, wrist 1e, and robot hand 1b in the opposite direction to the above, and then lower the robot 1 in the +V direction and store it in the tool magazine 4b. . Note that the mechanical operation, ie, the operation pattern, performed by modifying the correction amount determined by the correction formula for each tool having a different weight is selected by the tool table corresponding to each tool. The mechanical motion of the robot based on this selected motion pattern is controlled by a robot control device having a circuit configuration shown in FIG. a servo motor 22 for rotating the robot 1 in the Z direction, a servo motor 23 for rotating the robot hand 1b in the W direction, and a servo motor 24 for rotating the robot hand 1b in the W direction.
This is performed by controlling the servo motors 25 for vertical movement of the robot 1 in the V direction by predetermined amounts stored in the teachings. FIG. 6 is a block diagram of a flexible loader control device according to the present invention. In the figure, 7 is a teaching operation panel connected to a central processing unit CPU of a microcomputer 8. A ROM 9 and a RAM 10 are connected to the CPU of the microcomputer 8, of which the ROM 9 has an operation program storage area 9A, and the RAM 10 has an operation storage area 10A and a tool weight storage area 10B. Operation commands from the microcomputer 8 are transmitted to servo amplifiers 11, 12, 13, 14 and 15, thereby driving servo motors 21, 22, 23, 24 and 25, respectively, as described above. In addition, servo amplifiers 11, 12, 13, 1
4 and 15 have servo motors 21, 22, 23,
Feedback signals are provided from pulse generators 16, 17, 18, 19 and 20 provided at 24 and 25, respectively. Here, ROM9 is the microcomputer 8 that controls the flexible loader.
This ROM9 stores the control program of
Area 9 stores an operating program for the flexible loader. The microcomputer 8 reads these programs and generates operation commands for the flexible loader. The RAM 10 is used by the microcomputer 8 to change data contents when processing data, to store the order of operations, to create operation commands, to store and correct them. Of this RAM 10, especially the operation storage area 1
To explain about 0A, among the flexible loader movements stored in the movement storage area 9A, the movement storage area 10A stores teaching movements given by the operator corresponding to teaching command numbers such as H81 and 85 shown in the program example. It is.
Therefore, when the flexible loader actually operates, the operation is performed according to the contents of the operation program storage area 9A, and the H number is the same as the operation stored according to the H number in the operation storage area 10A. The contents are executed. Also, area 10
B is a tool weight storage area in which magazine numbers and tool weights as shown in Table 1 are stored in association with each other from the teaching operation panel 7 in advance, and the content is stored in the operation storage area 10A based on the difference in tool weight. Correct. In this way, the operation command from the microcomputer 8 is appropriately amplified by the servo amplifiers 11, 12, 13, 14, and 15, and then the servo motor 21,
22, 23, 24, and 25, respectively, thereby driving each part of the flexible loader, that is, the robot 1, by a predetermined amount. Table 2 is a tool table for exchanging tools with different clamp types using one exchange device, and instead of the tool table in Table 1, RAM1
By storing it in area 10B of 0, it is used for automatic tool exchange in a multi-tasking machine equipped with tools of different clamp types. Further, the mechanical operations of the robots, which have different tool mounting operation orders due to different clamp types, ie, operation patterns, are selected according to each tool table.

[Table] Below are examples of robot operation programs, including a dovetail clamp type tool as shown in Figure 4, and a
An example of operation in the case of a taper clamp type tool as shown in the figure is shown. In other words, in the case of a dovetail groove, the tool holder 5a example is commanded to move the V axis and the tool magazine 4a side is instructed to move the Z axis, and in the case of a taper, the tool holder 5b side is instructed to move the Z axis,
On the tool magazine 4b side, commands are given to move the V-axis, respectively, and tools are attached and detached. Note that the dovetail groove is effective as a clamp type for turning tools, and the taper is suitable as a clamp type for rotating tools.

【table】

[Table] The above is an example of a robot operation program, but if conventional weight correction was not performed, programs with changed program numbers and teaching amount memory numbers (H81, etc.) would have to be prepared for the number of tools, and each Although it is necessary to teach each tool, if correction is performed based on weight as in the present invention, there is no need for such complicated program creation. FIG. 7 shows a flowchart for teaching the operation. The teaching mode of this flowchart is exactly the same as the flowchart shown in Fig. 8 of JP-A No. 56-152552, so the explanation will be omitted. The command amount stored in area 10B is corrected according to equation (2) using the tool weight stored in area 10B, and then each operation is executed in a predetermined order to complete the command H81. . As described above, in the present invention, the displacement △θ of the robot arm is calculated from the weight table of each tool inputted in advance.
By calculating _X , Δθ _y and automatically determining the correction amount, by teaching only one tool, the correction amount is determined for all tools with weight differences, making setup easier. Furthermore, by teaching the operating order of the robot according to the clamp type of the tool, tools of different clamp types can be automatically replaced by one robot. Further, since a storage area is provided in the robot control device, there is no need to prepare an operation program for each tool.

[Brief explanation of the drawing]

FIG. 1A is a side view showing the relationship between the claw 1c of the robot 1 and the tool post 3, FIG. 1B is a full perspective view, FIG. 2 is a line diagram showing the relationship between gripping tool weight W and angle change, and FIG. Figure 3B shows the robot 1, tool holder 5a, and tool magazine 4 at the program origin.
FIG. 4 is a side view and front view showing the arrangement relationship of FIG. FIG. 6 shows a block diagram of a control device according to the present invention, and FIG. 7 shows an example of a flowchart. In the figure, 1 is a robot, 1a is a robot arm, 1b is a robot hand, 1c is a robot claw, 2 is a replacement tool, 3 is a tool rest, 4a, 4b
is a magazine, 5a, 5b are tool holders, 6a,
6b is a fixed rotary tool, 7 is an operation panel, 8 is a microcomputer, 9 is a ROM, 9A is an operation program storage area, 10 is a RAM, 10A is an operation storage area, 10B is a tool weight storage area, 11-
15 is a servo amplifier, 16 to 20 are pulse generators, and 21 to 25 are servo motors.

Claims (1)

[Claims] 1. An automatic exchange or automatic assembly system for conveyed objects using a flexible loader device, comprising a memory that stores a table specifying conveyed objects and corresponding operations of the flexible loader,
The operation pattern of the flexible loader can be automatically selected according to the object to be transported.It is equipped with a storage area in the control device of the flexible loader and a storage area for the weight of the object to be transported, so that the weight of the object to be transported can be stored in advance in the table of objects to be transported. and modifying the operation program contents of the flexible loader stored in the operation storage area based on the weight difference between the selected tool and the reference tool in the weight of the transported object. How to use flexible loader equipment. 2. In an automatic exchange or automatic assembly system for conveyed objects using a flexible loader device, for each conveyed article having a wide variety of attachment types and weights, which are exchanged or assembled between the conveyed article storage means and the conveyed article attachment means. The transport/replacement or assembly operation of the flexible loader is selected based on the conveyed object table including the mounting type and weight stored in the storage area in the control device of the flexible loader, and a predetermined conveyed object is loaded onto the conveyed object mounting means. A flexible loader device, characterized in that, prior to mounting the flexible loader, a positioning error of the flexible loader is corrected based on the weight of the transported object. 3. In a storage area that includes a microcomputer 8 that controls the operation of the flexible loader, a ROM 9 that is connected to the microcomputer 8 and gives fixed operation commands, and a RAM 10 that inputs and outputs operation modification commands, the ROM 9 stores the operation program of the loader device. The RAM 10 includes an area 9A for storing contents for changing the operation of the flexible loader stored in the area 9A, and an area 10A for storing contents stored in the operation storage area 10A based on the difference in the weight of the transported object. 3. The flexible loader device according to claim 2, further comprising a transported object weight storage area 10B for correcting the weight of the transported object.