Plastic article or earthenware shaping or treating: apparatus – Female mold and charger to supply fluent stock under... – With means to close mold
Patent
1985-07-23
1987-02-10
Miles, Tim
Plastic article or earthenware shaping or treating: apparatus
Female mold and charger to supply fluent stock under...
With means to close mold
4254516, B29C 4566
Patent
active
046420444
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a toggle type lock in an injection molding apparatus.
BACKGROUND ART
A conventional toggle type lock in an injection molding apparatus is driven by a hydraulic mechanism. For this reason, a hydraulic pump, valves or the like complicate the construction of the conventional lock drive mechanism. The locking operation must be controlled by a hydraulic pressure. As a result, locking speed control is complex and cannot be easily performed.
SUMMARY OF THE INVENTION
It is an object of the present invention to eliminate the drawbacks of the prior art and to provide a toggle type lock whose locking operation can be easily controlled.
A lock in an injection molding apparatus for causing a toggle mechanism to perform locking according to the present invention, comprises a servo motor and a transmission mechanism having a screw and a nut mechanism for converting the rotational force of the servo motor to a linear force, the toggle mechanism being driven by an output from the transmission mechanism.
In this manner, according to the present invention, the servo motor is used as a drive source of the toggle mechanism for performing locking, so that locking speed control can be easily performed to obtain a desired locking speed. Furthermore, since a toggle mechanism is employed, a compact servo motor can be used, thus resulting in a simple structure and easy maintenance. When a locking force is controlled, a position sensor mounted on the servo motor precisely controls the positions of the screw and the toggle mechanism, thereby simplifying locking force control.
When molds are closed and continuously locked at a predetermined pressure, a link of the toggle mechanism is kept straight. The toggle mechanism itself is stably operated to hold the molds while the molds are locked. For this reason, not much power need be supplied to the servo motor. Only a small current need be supplied to the servo motor only for preventing the molds and the link of the toggle mechanism from being moved due to vibrations or the like, thereby decreasing energy consumption.
Unlike the conventional lock, a hydraulic mechanism is not used, so that operation reliability is improved. In the conventional lock, a hydraulic pump is operated with power to generate a hydraulic pressure used to drive the drive mechanism. In order to maintain a predetermined pressure, a large power loss occurs. However, according to the present invention, electric power is used only to drive the servo motor, and the drive mechanism is directly driven by the output from the servo motor. As a result, an energy loss can be decreased.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a first embodiment of the present invention;
FIG. 2 shows a second embodiment of the present invention; and
FIG. 3 shows a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a first embodiment of the present invention. Reference numeral 1 denotes a servo motor; 2 and 3, gears, respectively; 4, a nut fixed on the gear 3; and 5, a screw engaged with the nut 4. The gears 2 and 3, the nut 4, the screw 5 and the like constitute a transmission mechanism for transmitting power from the servo motor 1 to a toggle mechanism 6. The toggle mechanism 6 is of double toggle type. One end of each of links 9 and 9' is pivotally supported by a crosshead 10 mounted at a distal end of the screw 5. The other end of each of the links 9 and 9' is pivotally supported by a corresponding one of links 7 and 7'. Links 8 and 8' are pivotally supported by the links 7 and 7', respectively. The links 7 and 7' are pivotally supported by a fixed back pressure plate 12. The links 8 and 8' are pivotally supported by a movable base 11. The links 7 and 7', 8 and 8' and 9 and 9' and the crosshead 10 constitute the toggle mechanism 6. Reference numerals 14 and 15 denote molds, respectively. The molds 14 and 15 are fixed on the mova
REFERENCES:
patent: 2358686 (1944-09-01), Caron
patent: 2498264 (1950-02-01), Goldhard
patent: 3345691 (1967-10-01), Aoki
patent: 4341511 (1982-07-01), Lawrent et al.
patent: 4360335 (1982-11-01), West
Fukuroi Takeshi
Ishikawa Yasushi
Fanuc Ltd
Miles Tim
LandOfFree
Lock does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lock, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lock will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2361534