MANUAL OPERATION SYSTEM FOR MACHINE CONTROLLED BY NUMERICAL CONTROL UNIT

Abstract: A manual operation system for a machine controlled by a numerical control unit (1). This system makes it possible to perform a manual operation following the same operating pattern as that of an automatic operation. When it is judged that manual instructions are being produced from selected switches (33a, to 33g, 34a, 34b) through a central processing unit (6) for a programmable controler, the machine is con­ trolled by a manual operation program that includes pre­ determined portions of an automatic operation program, and the operation according to the same operating pattern as that of the automatic operation is executed starting from the pre­ sent position.

Description: The present invention relates to a manual operation system for a machine controlled by a numerical control apparatus, wherein particular operations in a manual operation mode can be performed according to the same operation pattern as in an automatic operation mode. In a conventional machine controlled by a numerical control apparatus, a type of manual mode called jog feed is provided which allows feeding of a machine at a constant speed while a manual feed switch is kept on. Because of this constant speed, operations in this manual feed mode differ from those in the automatic operation mode (in which various feed speeds are generally preprogrammed). Consequently, if the same operation pattern as in automatic operation is required in manual operation, this requirement cannot be satisfied. In conventional injection molding machines, particularly in a conventional hydraulic injection molding machine, an actuator such as a hydraulic valve should be operated in an identical way in both the manual and automatic operation modes. For this reason, it would be desirable if the injection molding machine could follow the same operation patterns in both automatic and manual operation modes. It is therefore desirable to provide a manual operation system for a machine controlled by a numerical control apparatus, wherein the same operation pattern as in the automatic operation mode can be performed in the manual operation mode. US-A-4 115 858 discloses a machine tool controller for automatically controlling the Z-axis (spindle axis) operations of a machine tool during milling, boring operations and the like. Memory locations are each associated with a set of data for controlling the spindle in various operations, and the designation of any one memory location permits a predetermined operation to be carried out. According to the present invention, there is provided a manual operation system for a machine controlled by a numerical control apparatus, comprising switch discriminating means for discriminating actuation states of selection switches, and memory means for storing operation programs including manual operation programs for performing individual tasks in the manual operation mode, the machine being operable in a manual operation mode by holding down a manual feed switch; characterised in that:- said manual operation programs each include a determining portion for determining the current operation state of the machine and a predetermined portion of an automatic operation program used in an automatic operation mode, said determining portion being used to decide where to begin execution in said predetermined portion, whereby said machine is operable in the manual operation mode to perform selectable individual tasks in the same way as in the automatic operating mode whilst taking into account the current operation state of the machine. By means of the above a manual operation program (that is, a program for carrying out a single task, such as opening a clamp, as and when required by an operator) includes a predetermined portion of an automatic operation program (i.e. a program for carrying out a series of tasks fully automatically). The manual operation program is executed upon actuation of a selection switch means, and allows a numerically controlled injection molding machine to use the same operation pattern in the manual operation mode as in the automatic operation mode during the performance of certain individual tasks. Reference is made, by way of example, to the accompanying drawings in which:- Fig. 1 is a view showing the main part of an injection molding machine to which an embodiment of the present invention is applied; and Fig. 2 is a graph showing a mold opening operation pattern according to this embodiment. Fig. 1 shows the construction of the main part of an injection molding machine to which an embodiment of the present invention is applied. A computer built-in numerical controller (to be referred to as a CNC controller) 1 is connected to an operation panel with a display (to be referred to as an MDI/CRT) 2, a main operation panel 3 is arranged on the housing of the injection molding machine, and a servo circuit 4 for each axis is provided for controlling and driving corresponding servo motors for mold clamping, die height adjustment, ejector, injection, metering, and nozzle touch. The main control panel 3 includes a power switch 31, operation mode selection switches 32a to 32c for respectively setting the automatic, semi-automatic, and manual operation modes, manual operation object selection switches 33a to 33g for selecting mechanisms such as a clamp (i.e. a mold clamping mechanism) of the injection molding machine to be operated in the manual operation mode, and direction selection switches 34a and 34b for selecting a movement direction of the selected mechanism. The CNC controller 1 includes an NC central processing unit (to be referred to as an NCCPU) 5 and a programmable controller central processing unit (to be referred to as a PCCPU) 6. The NCCPU 5 and the PCCPU 6 are connected to each other through an interface 7. The NCCPU 5 is connected to a ROM 8 for storing control programs for controlling the entire injection molding machine. The NCCPU 5 is also connected to the servo circuits 4 through a bus 12 and an interface 11. The PCCPU 6 is connected to a ROM 9 for storing a sequence program. The interface 7 is connected to the MDI/CRT 2, the main control panel 3, and a nonvolatile RAM 10. The RAM 10 stores various automatic and manual NC programs such as an automatic operation program of the injection molding machine, a manual operation program for only mold opening operation of the clamp, and a manual operation program for only mold clamping operation of the clamp. The nonvolatile RAM 10 stores various molding conditions such as a mold clamping speed, an injection rate, and a holding pressure, which are set by the use of the MDI/CRT 2. In this embodiment, macro variables are utilised to set and store these molding conditions. In the stop mode of the injection molding machine, the PCCPU 6 monitors the actuation states of the switches on the main operation panel 3 according to the program sequence stored in the ROM 9 and selects the appropriate automatic or manual program from the RAM 10 in response to an output signal from the main operation panel 3. The selected program code is set in a selected program register under the control of the PCCPU 6. The PCCPU 6 also sends a start instruction to the NCCPU 5. In response to this instruction, the NCCPU 5 reads out an NC program corresponding to the selected program code from the RAM 10. The readout program is executed to drive all axis servo motors through the corresponding servo circuits 4. During execution of the NC program, the PCCPU 6 monitors the actuation states of the various switches on the main operation panel 3. When a stop instruction is input, the PCCPU 6 sends a stop instruction to the NCCPU 5 so as to interrupt the execution of the program. For example, when the automatic switch 32a is depressed, the PCCPU 6 detects depression of the switch 32a and selects the automatic operation program. The automatic operation program code is written in the register, and the NCCPU 5 executes the automatic operation program according to the contents stored in the register. When a manual operation instruction is generated, the PCCPU 6 monitors the manual switch 32c, the manual operation object selection switches 33a to 33g, and the direction selection switches 34a and 34b to determine which switches are depressed. The PCCPU 6 then selects a manual operation program stored in the nonvolatile RAM 10 to cause the selected mechanism to perform the same operation as in the automatic operation mode according to each driving direction. The code of this program is set in the register, and the NCCPU 5 executes the selected program according to the code stored in the register. As an example of manual operation assisted by manual operation programs, a case will be described wherein the clamp (the mold clamping mechanism of an injection molding machine) is manually fed in the mold opening direction. The mold opening operation of the clamp (Fig. 2) is performed in the same way as in the automatic operation mode. Mold opening is started from a mold closed position L1 at a low speed V1 and then a high speed V2. The mold opening operation continues at a low speed V3 to a mold opening end position L4. The speed switching positions L1, L2, L3 and L4 and mold opening speeds V1, V2 and V3 are set using macro variables on the operation panel and are stored in the nonvolatile RAM 10. More specifically, the mold closed position L1, the high-speed mold opening start position L2, the low-speed mold opening start position L3, and the mold opening end position L4 are stored at positions of macro variables #500 to #503, respectively. The mold release speed V1, the high-speed mold opening speed V2, and the low-speed mold opening speed V3 are stored at positions of macro variables #504 to #506. The current position of the clamp is stored at a position of a macrovariable #5022. In the stop mode of the injection molding machine, if the operator sequentially depresses the manual selection switch 32c, the clamp switch 33c, and the opening direction switch 34a so as to manually open the molds, the CPUs 5 and 6 are operated as described above. The manual mold opening operation program is selected, and the selected program is executed under the control of the NCCPU 5. The manual mold opening operation program is as listed below, and the injection molding machine is operated according to this program:- As is apparent from the above program sequence, each manual operation program consists of a program (work Nos. 10 to 40 in the above example) for searching the program execution start addresses according to the current operation position of the injection molding machine, and part of the automatic operation program (corresponding to work Nos. 50 to 70). In the manual mold opening operation, if the current clamp position represented by the storage content of the macro variable #5022 is smaller than the value represented by the high-speed mold opening position L1 stored at the address of macro variable #501, the program jumps to work number 50, and the operations in work No. 50 and the subsequent numbers are performed. More specifically, mold opening continues from the current clamp position to the high-speed mold opening position L2 (#501) at the mold release speed V1 (#504). Mold opening is then performed up to the low-speed mold opening position L3 (#502) at the high-speed mold opening speed V2 (#505) and then up to the mold opening end position L4 (#503) at the low-speed mold opening speed V3 (#506). The program is then ended. This operation pattern is the same as the mold opening operation pattern based on the automatic operation program. If the current clamp position represents a value larger than that represented by the high-speed mold opening start position L2 (#501) and at the same time smaller than that represented by the low-speed mold opening start position L3 (#502), the program jumps to work No. 60, and the instructions in work Nos. 60 to 80 are performed. However, if the current clamp position falls within the range between the low-speed mold opening start position L3 (#502) and the mold opening end position L4 (#503), the program jumps to work No. 70, and the instructions in work Nos. 70 and 80 are executed. On the other hand, if the current clamp position represents a value larger than that represented by the mold opening end position L4 (#503), the program jumps to work No. 80, and the instruction at this address is executed. The program is then ended. The above embodiment exemplifies the case of an injection molding machine controlled by the numerical control apparatus. However, the present invention is also applicable to a machine such as a robot controlled by a numerical control apparatus.

Claims: A manual operation system for a machine controlled by a numerical control apparatus, comprising switch discriminating means for discriminating actuation states of selection switches (32, 33, 34), and memory means (10) for storing operation programs including manual operation programs for performing individual tasks in the manual operation mode, the machine being operable in a manual operation mode by holding down a manual feed switch (32c); characterised in that:- said manual operation programs each include a determining portion for determining the current operation state of the machine and a predetermined portion of an automatic operation program used in an automatic operation mode, said determining portion being used to decide where to begin execution in said predetermined portion, whereby said machine is operable in the manual operation mode to perform selectable individual tasks in the same way as in the automatic operating mode whilst taking into account the current operation state of the machine. A system according to claim 1, wherein said selection switches comprise a plurality of manual operation object selection switches (33a ... 33g) corresponding to respective mechanisms of the machine and direction selection switches (34a, 34b) for selecting an operation direction of said mechanisms, said switch discriminating means discriminating the states of said selection switches (33a ... 33g, 34a, 34b) so as to determine an individual task being selected and thus the manual operation program to be executed. A system according to claim 1 or 2, wherein said memory means (10) also stores data defining the current operation state of the machine, said determining portion of each manual operation program performing a search of said data in order to determine the current operation state. A system according to claim 1, 2 or 3, wherein the machine controlled by the numerical control apparatus is an injection molding machine. A system according to claim 3 and 4, wherein said individual tasks include a mold opening operation, and wherein said memory means (10) stores data on speed switching positions and mold opening speeds for the mold opening operation.

Inventors: OTAKE, HIROMASA 4-5-3, MINAMI-CHO
Applicants: FANUC LTD.
Application year: 1986
Main classification: G05B19
IPC codes: B29C45, G05B19