This is a U.S. national stage of application No. PCT/DE00/03575, filed on Oct. 4, 2000. Priority is claimed on that application and on the following application: Country: Germany, Application No.: 100 05 676.8, Filed: Feb. 7, 2000.
1. Description
The invention relates to an ejector device for an injection-molding machine for plastics, having at least one ejector pin, which can be moved toward the mold and away from the latter through the center of a moveable die clamping plate by an actuator.
2. Description of the Related Art
EP 0 585 671 A1 has disclosed an ejector for molding dies in the case of injection-molding machines, in which an electric motor provided on a mold mounting plate is seated, the motor being connected continuously, for purposes of actuation, by means of a mechanism to a rotatable threaded spindle, which is connected to an ejector plunger.
EP 0 890 426 A2 has disclosed a device in which a servomotor is connected by an endless belt to a recirculating-ball screw, which is in operative connection with an ejector pin.
The ejector units known from the above-mentioned documents not only suffer from the disadvantage of a complex construction but also of not inconsiderable wear.
It is an object of the invention to provide an ejector device for an injection-molding machine which, while being of simple structural design and economical in terms of energy consumption, requires little maintenance and is reliable and takes up only a little free space in the region of the drive for the moveable die clamping plate.
According to the invention, a linear motor is provided outside the central axis of the injection-molding machine and is connected to the ejector pin by means of bar-shaped force-transmission elements. The linear motor is secured on the moveable die plate and arranged parallel or at right angles to the principal axis of the latter.
In a refinement of the invention, a two-armed lever is used, the end of which is connected to the ejector pin and the other end of which is connected by means of a compression link to the linear motor and which is connected approximately centrally, by means of a tension link, to the movable die clamping plate.
In another refinement of the invention, a two-armed lever is provided, the end of which is connected to the ejector pin, the other end of which is connected to the linear motor by means of a compression link, and which is connected approximately centrally to the moveable die clamping plate by means of a tension link.
The two-armed lever is configured in such a way that the lever ratios are adjustable and, in a refinement, the lever has various holding elements, while, in a further refinement, the lever is of telescopic configuration to enable the lever ratios of the lever component a which is oriented toward the linear motor and/or the lever component b which is oriented toward the ejector pin to be adjusted.
In a further refinement of the invention, a mechanism formed by a two-armed and a one-armed lever is provided, permitting linear guidance of the ejector pin over a sufficient range. This refinement makes it possible to dispense with the use of a bearing for the ejector pin. Insofar as bearings are used, sliding bearings, in particular porous bearings, are provided.
The linear motors used are electric motors, which have recirculating-ball or planetary-roller screws. It is furthermore proposed to use reluctance motors as linear motors, in which the comb-shaped inductor is connected either to the moveable die clamping plate or, by means of a compression or tension link, to the two-armed lever.
In a further refinement of the invention, a rigid lever is used, which is driven by a linear motor arranged parallel to the principal axis.
All the figures show a fixed die clamping plate 11 and a moveable die clamping plate 12 of an injection-molding machine 10. Secured on the moveable die clamping plate 12 there is in each case a linear motor 21, which is in operative connection via force-transmission elements 30 in the form of levers with an ejector pin 41, which can be passed centrally through the moveable die clamping plate 12.
In
The ejector plate 44 is connected to a two-armed lever 31 by means of a compression link 33. At one end, the two-armed lever 31 is secured by means of a bracket 13 in a manner that allows angular motion and, at its other end, is connected to the linear motor 21 by means of a tension link 32. The linear motor 21 is configured as a reluctance motor 23, the comb-shaped inductor 24 of which is arranged at the head of the die clamping plate 12, parallel to the principal axis I.
The ratios of lever-arm component a to lever component b of the two-armed lever 31 can be adjusted by means of holding element 34 and 35 in conjunction with the brackets 13 and 14. In
The end of the holding bar 45 is secured on one end of the two-armed lever 31 in a manner that allows angular motion.
The two-armed lever is held approximately centrally, by means of the tension link 32, on brackets 13 or 14, which are secured on the moveable clamping plate 12.
Provided at the other end of the two-armed lever 31 is a compression link 33, which is in operative connection with a spindle 22 of the linear motor 21 provided here.
In
The two-armed lever 31 is configured as a telescope, allowing the ratios of the lever arms a and b to be adjusted in an infinitely variable manner as required.
One end of the two-armed lever 31 is connected by a compression link 33 to the linear motor 21, which is configured as a reluctance motor 23. The comb-shaped inductor 24 has adjusting element 25, which allow the axis II of motion to be adjusted relative to the central axis I.
In
The two-armed lever 31 has an angular configuration and is connected approximately centrally to the moveable die clamping plate 12 at a bracket 13 in a manner that allows angular motion.
Provided at the other end of the two-armed lever 31 is a compression link 33, which is connected to the holding bar 45, which is connected to the ejector plate 44 and the ejector pin 41 secured thereon.
The holding bar 45 is mounted in a bearing 15, which is connected to the moveable clamping plate 12.
The ejector plate 44 connected to the rigid arm 39 is mounted by means of the bearings 42 and 43 on guide pins 16 and 17, which are secured on a moveable die clamping plate 12.
Number | Date | Country | Kind |
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100 05 676 | Feb 2000 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE00/03575 | 10/4/2000 | WO | 00 | 8/6/2002 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO01/58659 | 8/16/2001 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
1781339 | Oliver et al. | Nov 1930 | A |
3752622 | Vladana | Aug 1973 | A |
3807682 | Catinella et al. | Apr 1974 | A |
3807915 | Rees | Apr 1974 | A |
4635463 | Dumschat | Jan 1987 | A |
5067892 | Rahn et al. | Nov 1991 | A |
5481147 | Kaplan et al. | Jan 1996 | A |
6113376 | Eppich | Sep 2000 | A |
6183235 | Taniguchi et al. | Feb 2001 | B1 |
6478566 | Ito et al. | Nov 2002 | B1 |
20020110616 | Meschia | Aug 2002 | A1 |
Number | Date | Country |
---|---|---|
0585 671 | Aug 1993 | EP |