Plastic article or earthenware shaping or treating: apparatus – Control means responsive to or actuated by means sensing or...
Patent
1988-05-25
1989-09-26
Hoag, Willard
Plastic article or earthenware shaping or treating: apparatus
Control means responsive to or actuated by means sensing or...
72 6, 72 19, 72451, 100 50, 100272, 425149, 4254516, 425593, B29C 4358, B29C 4576
Patent
active
048696595
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
1. Technical Field The present invention relates to a toggle-type die-fastening apparatus of an injection molding machine.
2. Background Art
As shown in FIGS. 1 and 2, a conventional toggle-type die-fastening apparatus of an injection molding machine has the following construction. A die-fastening force adjusting nut 1 registers with a toggle support 4 and is threaded onto the end portion of a corresponding tie bar 3 that is closer to the toggle support 4. Two pairs of links 17, each pair comprising two links, are linked to one another in such a manner that the two pairs are symmetrical with respect to a die-fastening cylinder 16 therebetween. The links 17 are disposed between the toggle support 4 and a movable platen 15 so that the support 4 and the platen 15 are connected to each other through the links 17. Further, a cross head 18 is mounted on the tip of a rod of the die-fastening cylinder 16 and is connected to one link 17 of each link pair through further links 19. With this construction, the die-fastening force adjusting nut 1 is adjusted by being rotated via a gear 20 in order to set a die-fastening force, so that, when the rod of the die-fastening cylinder 16 is extended, the movable platen 15 advances along the tie bars 3, and, when the tie bars 3 are extended, a predetermined die-fastening force can be provided at the front end of the advanced platen 15 as the reaction of a cylinder force which has been amplified by the toggle mechanism 17, 18, and 19.
The conventional apparatus, however, has the following problem. During the operation of the molding machine, if the thermal balance in the molding machine changes, various parts of the machine, including the components of the toggle, become expanded or contracted. In consequence, the die-fastening force of the toggle tends to be slightly varied between the tie bars, making it difficult for the toggle to apply a constant die-fastening force uniformly over the entire mold. Accordingly, the conventional apparatus is not suitable for use in forming high-precision products such as disks, because dimensions of such products must be determined to a very high precision.
The present invention has been accomplished to eliminate this problem of the prior art. An object of the present invention is to provide a toggle-type die-fastening apparatus which is capable of applying the necessary die-fastening force uniformly over an entire mold.
DISCLOSURE OF INVENTION
According to the present invention, there is provided a toggle-type die-fastening apparatus having a plurality of tie bars which are each fixed at one end thereof to a fixed platen and which axially slidably support a movable platen, a toggle support having holes through which the other ends of the tie bars are inserted so as to be supported by the toggle support, die-fastening force adjusting nuts which are threaded onto the other ends of the tie bars and which register with the outer surface of the toggle support, and a toggle mechanism disposed between the movable platen and the toggle support for pressing the movable platen against the fixed platen. The apparatus is characterized by comprising: adjusting cylinders which are each formed by enlarging a corresponding hole in the toggle support on the side thereof on which the adjusting nuts register with the toggle support; pistons slidably disposed within the adjusting cylinders and being capable of pressing against the corresponding adjusting nuts in the direction in which the corresponding tie bars are acted on by tensile forces; a hydraulic circuit for supplying hydraulic pressure to the adjusting cylinders; a pressure adjusting valve provided in the hydraulic circuit for adjusting the pressure within the adjusting cylinders; and a setting device for setting a die-fastening force, wherein the pressure adjusting valve is controlled in accordance with signals from the setting device.
By virtue of the provision of the adjusting cylinders, the toggle-type die-fastening apparatus in accordance with the present invention is capable of eq
REFERENCES:
patent: 3606641 (1971-09-01), Carrieri et al.
patent: 3669599 (1972-06-01), Snider et al.
patent: 3734673 (1973-05-01), Paterson et al.
patent: 3819774 (1974-06-01), Eggenberger et al.
patent: 4059383 (1977-11-01), Tsutsumi
patent: 4281977 (1981-08-01), Farrell
patent: 4301100 (1981-11-01), Farrell
patent: 4685876 (1987-08-01), Loscei
Saito Toshiro
Sakai Seiya
Suzuki Mitsuo
Hoag Willard
Sumitomo Heavy Industrie's, Ltd.
LandOfFree
Toggle-type die-fastening apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Toggle-type die-fastening apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Toggle-type die-fastening apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-184856