Electricity: motive power systems – Positional servo systems – Program- or pattern-controlled systems
Patent
1989-02-09
1990-11-13
Shoop, Jr., William M.
Electricity: motive power systems
Positional servo systems
Program- or pattern-controlled systems
318571, 425145, 425149, 367473, B29C 4576
Patent
active
049704478
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrically-operated injection molding machine having servomotors as drive sources for various operating sections, and more particularly to a software servo control apparatus for use in an electrically-operated injection molding machine, which is capable of changing servo control variable constants and has a great versatility, and is further capable of performing appropriate torque control.
2. Description of the Related Art
Typically, a conventional electrically-operated injection molding machine is provided with hardware servo circuits each including a position control unit, a speed control unit, and an electric current control unit, for controlling position, speed, and torque of each of plural servomotors associated with various operating sections of the injection molding machine. Also, it has been known to employ a servo circuit of a type having a torque limit means arranged between the speed control unit and the electric current control units for restricting the output torque of an associated servomotor to a commanded torque limit value.
The injection molding machine includes various operating sections such as an injection mechanism, a mold clamping mechansim, etc.; that is, it includes various control axes such as an injection axis, a screw rotation axis, a clamp axis, etc. Therefore, conventionally, it has been necessary to provide the above-mentioned hardware servo circuits for respective axes. Moreover, to change various servo control variable constants which determine reponse characteristics of various sections of a servo system, and the like, replacement of part or all of servo circuit components is required. In addition, since the unit of the torque limit value for presure control is determined in dependence on the hardware arrangement which forms the pressure control system, there is a restriction in improving accuracy in pressure control.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a software servo control apparatus for use in an electrically-operated injection molding machine having a servomotor as drive source, which is capable of controlling the drive of the servomotor without the need of employing a hardware servo circuit.
In order to achieve the above-mentioned object, according to the present invention, a software servo control apparatus for the use in an electrically-operated injection molding machine comprises means for executing a predetermined control program for servo control, and means for driving a servomotor in accordance with a control output from the program executing means.
As mentioned above, according to the present invention, since the drive of a servomotor is controlled in accordance with a control output from means for executing a predetermined servo control program, the drive of the servomotor can be controlled, without the need of using hardware servo circuits, so as to achieve desired control operations in an injection molding machine, and various servo control variable constants can be changed solely by changing the servo control program so as to easily achieve alteration and adjustment of control operation conditions. Further, appropriate pressure control can be achieved since the output torque of the servomotor can be controlled through the medium of the software process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an essential part of an injection molding machine eqipped with a software servo control apparatus according to an embodiment of the present invention; and
FIG. 2 is a block diagram of an injection molding machine equipped with a conventional hardware servo apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Prior to explaining the arrangement of the present invention, an explanation as to a typical conventional arrangement will be given with reference to FIG. 2. In FIG. 2, an arrangement associated with an injection axis alone of an injection molding machine is shown, and illustrations and explanations for m
REFERENCES:
patent: 4411609 (1983-10-01), Yoshii et al.
patent: 4695237 (1987-09-01), Inaba
patent: 4718841 (1988-01-01), Kiya
patent: 4721589 (1988-01-01), Harris
patent: 4734025 (1988-03-01), Kawamura et al.
patent: 4755123 (1988-07-01), Otake
patent: 4759705 (1988-07-01), Otake et al.
patent: 4774675 (1988-09-01), Kagawa
patent: 4826640 (1989-05-01), Neko
patent: 4828473 (1989-05-01), Otake et al.
Kamiguchi Masao
Neko Noriaki
Fanuc Ltd.
Ip Paul
Shoop Jr. William M.
LandOfFree
Software servo control apparatus for use in an injection molding does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Software servo control apparatus for use in an injection molding, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Software servo control apparatus for use in an injection molding will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-778915