JP2004025813A - Toggle type mold clamping device for molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To materialize a compact toggle type mold clamping device, with the interval between the pressure platen and the movable platen shortened by changing the toggle link pivoting means against the pressure platen. <P>SOLUTION: The center portion of the pressure platen 2 where a toggle driving device 13 locates is formed in an inward recess 6 which holds a link pin 15 together with a cross-head 12. Expanding slots 7 are provided on both sides in the opening of the recess 6. The ends of the toggle link 17 are inserted into the expanding slots 7 so that the toggle link 17 is pivoted. The toggle link 17 can be sunk into the recess 6 when the toggle is contracted. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a toggle-type mold-clamping device for a molding machine that opens and closes and mold-clamps a mold attached to a fixed platen and a movable platen by a toggle mechanism provided between the pressure receiving platen and the movable platen.
[0002]
[Problems to be solved by the invention]
A normal toggle-type mold clamping device is configured to support the end of a toggle link connected by a link pin to a receiving piece protruding from a facing surface of a fixed plate and a movable plate, and attach a toggle mechanism to both plates. The movable link is moved forward and backward with respect to the fixed board by folding or extending the toggle link by a toggle drive device provided at the center of the pressure receiving board.
[0003]
In the mold clamping of the mold divided and attached to the fixed board and the movable board, the tie bar is extended by the extension force after the mold is closed due to the extension of the toggle, and the tie bar reaction force is applied to the mold as the mold clamping force. Therefore, a force equivalent to the mold clamping force acts on the pressure receiving plate. In addition, since the mold clamping force is determined by the amount of extension of the tie bar, if the pressure receiving plate is deformed by the extension force, the tie bar cannot be extended by the amount of the deformation, and the set mold clamping force cannot be generated. . For this reason, the pressure receiving plate is formed to be thick to have rigidity.
[0004]
When the pressure receiving plate is formed to be thick, the mold clamping device becomes longer by that amount, and the tie bar provided between the fixed plate and the pressure receiving plate becomes longer. In addition, since the amount of elongation of the tie bar is proportional to the length, the toggle mechanism also needs to have a long working stroke, and thus the toggle type mold clamping device tends to be necessarily large in size.
[0005]
The present invention has been conceived in order to solve the problem of the toggle-type mold clamping device, and has as its object to simply change the pivot support means of the toggle link with respect to the pressure receiving plate, and maintain the working stroke as it is. It is another object of the present invention to provide a toggle-type mold clamping device of a new molding machine that can reduce the distance between the movable platen and the movable platen, thereby making the mold clamping device compact.
[0006]
[Means for Solving the Problems]
The present invention according to the above object, the fixed plate and the pressure receiving plate are connected by a tie bar, a driving device is installed in the center of the pressure receiving plate, and a toggle mechanism provided over the pressure receiving plate and a movable plate inserted through the tie bar, In a mold clamping device for opening and closing and clamping a mold attached to a fixed plate and a movable plate, a center portion of the pressure receiving plate where a toggle drive device is located is provided with an inward recess for accommodating a link pin together with a crosshead. In addition, a split groove is provided on both sides inside the opening of the recess, the end of one toggle link is inserted into the split groove to support the shaft, and the toggle link can be immersed in the recess when the toggle is reduced. It is to be done.
[0007]
Further, the toggle drive device of the present invention comprises a screw shaft rotatably supported by a bearing member at the center of the recess, and a cross head inside a nut member screwed with the screw shaft. The drive source for the shaft is an electric motor.
[0008]
Further, the toggle drive device includes a hydraulic cylinder installed outside the center of the pressure receiving plate, a piston rod that is telescopically inserted into the center of the recess from the hydraulic cylinder, and a crosshead attached to a tip of the piston rod. It also consists of.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail for a toggle type mold clamping device of a vertical molding machine.
FIGS. 1 to 3 show an embodiment of a toggle mechanism employing an electric servomotor as a drive source.
[0010]
In the drawing, reference numeral 1 denotes a fixed plate, 2 denotes a pressure receiving plate, and both plates are connected at four corners by tie bars 3, and the fixed plate side is installed on the machine base with the lower side. Reference numeral 4 denotes a movable plate which is inserted between the tie bars 3 and provided between the two plates. A mold 5 is divided and attached to the opposing surfaces of the movable plate 4 and the fixed plate 1.
[0011]
A central portion of the pressure receiving plate 2 is formed as a deep inward concave portion 6 which can accommodate a crosshead and a link pin described later. A plurality of parallel split grooves 7 for link insertion are provided on both sides inside the opening of the recess 6, and a shaft hole 8 perpendicular to the split groove 7 is formed in the pressure receiving plate 2. A bearing member 9 is fitted in the upper center of the recess 6.
[0012]
Reference numeral 10 denotes a double toggle mechanism (hereinafter, referred to as a toggle mechanism), which includes a ball screw shaft 11 (hereinafter, referred to as a screw shaft) rotatably supported at the center of the recess 6 by the bearing member 9 and a ball screw shaft 11. It comprises a drive device 13 comprising a crosshead 12 with a threaded nut member inside, and toggle links (hereinafter referred to as links) 16 and 17 having different lengths connected by an operation link 14 and a link pin 15.
[0013]
Of the links 16 and 17, the longer link 16 has an end portion supported by a support piece 19 protruding from the movable platen 4 with a support shaft 19, and the shorter link 17 has an end portion formed with the split groove. 7 and supported by a support shaft 20 and connected to the respective pressure receiving panels. The operating link 14 is rotatably connected to a lug projecting from a side portion of the crosshead 12 by a pin 21. The operating link 14 moves together with the crosshead 12, and the links 16 and 17 are linked by the link pin 15. The connection part is pulled or pushed back, and the toggle mechanism 10 is expanded and contracted.
[0014]
The toggle drive device 13 uses an electric servomotor 22 attached to a side of the pressure receiving plate 2 as a drive source, and includes a timing belt 25 wound around a pulley 23 at an outer end of a screw shaft and a pulley 24 on an electric servomotor side. The screw shaft 11 rotates. As a result, the crosshead 12 moves up and down the screw shaft 11 together with the internal nut member, and when the crosshead 12 is raised, the operating link 14 pulls the link pin 15 to fold the links 16 and 17 and raises the movable platen 4 to raise the metal. The mold 5 is opened. Further, at the time of lowering, the link pin 15 is pushed back and extended, the movable platen 4 is lowered to close the mold 5 and the mold is clamped by further extending.
[0015]
The embodiment shown in FIG. 4 exemplifies a case in which the toggle mechanism 10 is driven by hydraulic pressure, and is different from the embodiment in which the drive source shown in FIG. Thus, the toggle mechanism 10 has the same configuration. Therefore, the toggle mechanism 10 is denoted by the reference numeral, and the description is omitted.
[0016]
In this embodiment, the bearing member 9 of the recess 6 shown in FIG. 1 is replaced with a seat 26, and a hydraulic cylinder 27 is installed in the seat 26. The seat 26 has a through hole in the center, the piston rod 28 is positioned in the recess 6 through the through hole, the crosshead 12 is pin-connected to the tip of the piston rod 28, and the crosshead 12 is It is configured to move up and down.
[0017]
In any of the above-described embodiments, the central portion of the pressure receiving plate 2 where the toggle drive device 13 is located is formed in the inward recess 6 for accommodating the link pin 15 together with the crosshead 12, and the opening of the recess 6 is formed. Since the ends of the short links 17 are inserted into the split grooves 7 provided on both inner sides and are rotatably connected by the support shaft 20, the support shaft of the link 17 is located inside the pressure receiving plate 2, and As a result, the links are folded up to the inside of the pressure receiving plate, and the entire link 17 is immersed in the pressure receiving plate, and is removed from the working space between the pressure receiving plate 2 and the movable plate 4.
[0018]
Therefore, even if the operation stroke is the same as the toggle mechanism that supports the link on the receiving piece protruding from the conventional pressure receiving plate, the movable platen 4 approaches the pressure receiving plate side by the width of the link 17 immersed in the pressure receiving plate. I will do it. In addition, since the link end is inserted into the pressure receiving plate 2 and supported by the shaft, the distance between the pressure receiving plate 2 and the movable plate 4 can be set shorter by the amount of insertion. As a result, even in a toggle-type mold clamping device in which the thickness of the pressure receiving platen 2 is set to be large for imparting rigidity, the length of the mold clamping device can be shortened, and the entire structure can be made compact. Particularly in a vertical molding machine, the height of the mold clamping device can be designed to be low.
[0019]
The above embodiment describes a vertical molding machine in which the mold clamping device is installed vertically on the machine base. Since there is no change, the present invention can also be adopted as a toggle-type mold clamping device of a horizontal molding machine.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a main part of a toggle type mold clamping device of a molding machine according to the present invention when a mold is opened.
FIG. 2 is a longitudinal sectional side view of a link connecting portion of the above.
FIG. 3 is a longitudinal sectional view of a main part when a mold is closed.
FIG. 4 is a longitudinal sectional view of a main part when a mold is closed according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fixed board 2 Pressure receiving board 3 Tie bar 4 Movable board 5 Die 6 Recess 7 Split groove 9 Bearing member 10 Toggle mechanism 11 Screw shaft 12 Cross head 13 Toggle drive device 14 Operation link 15 Link pin 16, 17 Link 20 Support shaft 22 Electric servo motor 26 Seat 27 Hydraulic cylinder 28 Piston rod

Claims (3)

The fixed plate and the pressure receiving plate are connected by a tie bar, and a driving device is installed in the center of the pressure receiving plate, and a toggle mechanism provided between the pressure receiving plate and the movable plate inserted through the tie bar provides a fixed plate and a movable plate. In a mold clamping device that opens and closes and clamps the mounted mold,
The center portion of the pressure receiving plate where the toggle drive device is located is formed in an inward recess for accommodating the link pin together with the crosshead, and split grooves are provided on both sides inside the opening of the recess, and one of the split grooves is provided in the split groove. A toggle-type mold clamping device for a molding machine, wherein an end of a toggle link is inserted and supported so that the toggle link can be immersed in a recess when the toggle is reduced. The toggle drive device includes a screw shaft rotatably supported by a bearing member at the center of the recess, and a cross head with a nut member screwed into the screw shaft, and a drive source for the screw shaft is provided. 2. A toggle mold clamping device for a molding machine according to claim 1, wherein said device is an electric motor. The toggle drive device includes a hydraulic cylinder installed outside the center of the pressure receiving plate, a piston rod that is inserted from the hydraulic cylinder into the center of the recess so as to be extendable and contractable, and a crosshead attached to the tip of the piston rod. The toggle-type mold clamping device for a molding machine according to claim 1, wherein:

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