JP2009045939A - Toggle type mold clamping device of injection molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toggle type mold clamping device constituted by securing a plurality of molds to symmetric positions of a rotary platen in which the mold clamping force from a movable platen can be uniformly transmitted to the plurality of molds. <P>SOLUTION: The movable platen is arranged so as to be freely movable forward and rearward to a mold mounting platen by threading the movable platen through the tie bars coupling the mold mounting platen and a pressure receiving platen. The rotary platen is arranged in the platen face of the movable platen facing the mold mounting platen. A toggle mechanism is arranged between both the platen by coupling toggle links in the upper and lower positions of the pressure receiving platen and the movable platen. The abutting faces of the movable platen and the rotary platen are limited in the corresponding face of the plurality of mold securing faces set in the symmetric positions of the rotary platen. The mold clamping force by the toggle links in the upper and lower positions of the movable platen is uniformly transmitted to the plurality of molds. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mold clamping device of an injection molding machine that simultaneously molds a plurality of sets of symmetric molds by a toggle mechanism.

  The mold clamping device of the injection molding machine is a direct pressure type that directly clamps the mold by operating the ram by hydraulic pressure, and clamps the mold by expanding the force generated by the power source with a toggle mechanism. There is a toggle type. In the direct pressure type, a hydraulic cylinder and a ram are installed on the center line of the mold clamping device to pressurize the center of the movable platen.

  In the toggle type with an electric motor as the power source, a screw shaft that converts rotational motion into linear motion and a crosshead that moves the screw shaft to bend and stretch the toggle link are installed on the center line of the mold clamping device. ing. For this reason, since the link of the toggle link is limited to the vertical position, it cannot be pressurized by connecting the toggle link to the central part of the pressure receiving plate and the movable plate as in the direct pressure type, and the upper and lower sides of the movable plate are pressurized. Yes.

  The direct pressure type pressurizes the center of the movable platen, so when the mold is attached to the center of the movable platen and the mold placement platen, it is said that there is almost no influence on the die due to the bending of both plates. . However, when two sets of molds are mounted at symmetrical positions on both sides of the mold table and the movable plate and the mold is clamped, stress is transmitted from the center of the plate to both sides, and tensile force from the tie bar acts on both sides. For example, the two plates are bent so as to warp in the same direction, and the mold closing tends to be uneven. For this reason, it is said that it is not preferable for molding of products that require molding accuracy. As a solution to this problem, two mold clamping cylinders are arranged in parallel on the movable platen, and two molds are individually clamped simultaneously by the rams of each mold clamping cylinder to prevent bending during mold clamping. It has been broken.

In the toggle type, the movable platen is pressurized at the vertical position, so when the mold attached to the center of the movable platen and the mold placement plate is clamped, the upper and lower sides of the movable plate bend toward the mold placement plate. Since the mold placing plate is easily bent toward the movable platen by the tensile force of the tie bar, the mold clamping force on the mold tends to decrease due to the bending. As a means for reducing the clamping force due to this bending, a movable plate is attached to the top surface of the support mechanism having a truncated pyramid shape, and the clamping force is concentrated on the mold at the center of the movable plate by the support mechanism. is there.
JP 2000-117769 A JP-A-8-258103

  Even in the toggle type, when two sets of molds are mounted at symmetrical positions on both sides of the mold placing plate and the movable plate and the mold is clamped, the mold clamping force acting on both molds is reduced by the bending of the movable plate, Further, the mold closing is uneven and it is easy to open outward. Also, unlike the direct pressure type, where the pressurization position on the movable plate and the mold mounting surface are the same position, the toggle mounting type has the mold mounting surface in the middle of the vertical pressurization position by the toggle link. These toggle mechanisms cannot be juxtaposed to directly pressurize the molds simultaneously and individually. For this reason, it is difficult for the toggle type to attach a plurality of sets of dies and simultaneously mold a plurality of molded products, or to perform two-color or compound molding.

  The present invention has been conceived in order to solve the above-described problems in the toggle type mold clamping device, and its purpose is not to place a plurality of toggle mechanisms side by side, By being configured to transmit uniformly to the mold, new molding can be performed simultaneously, or two-color or composite molding of a plurality of molded products with high molding accuracy, which has been difficult to mold with a toggle mechanism. The object is to provide a toggle type mold clamping device.

  According to the above-described object, the present invention provides a movable plate that is connected to a mold placing plate and a pressure receiving plate with a tie bar, is inserted through the tie bar, and is movable forward and backward with respect to the mold placing plate, and a surface of the movable plate facing the mold placing plate. Toggle type with a plurality of molds attached to the symmetric position of the rotating disk. In the mold clamping device, the contact surface between the movable platen and the rotating plate is limited to a corresponding surface with a plurality of mold mounting surfaces set at symmetrical positions of the rotating plate, and the mold clamping force by the toggle link at the vertical position is It is that it is uniformly transmitted to the mold.

  In the above configuration, the contact surface between the movable platen and the rotating plate is limited to the corresponding surface with a plurality of mold mounting surfaces, so that the mold clamping force by the toggle mechanism is concentrated on the mold mounting surface of the rotating plate. Even when the movable plate is bent due to the mold clamping force, the mold clamping force can be uniformly applied to the plurality of molds to perform the mold clamping. As a result, it is possible to prevent the mold from opening due to bending that tends to occur when a plurality of molds are mounted in symmetrical positions. Even with a mold clamping device equipped with a normal toggle mechanism, a plurality of high-precision molded products Can be formed simultaneously.

  The drawings show details of the toggle type mold clamping device according to the present invention, in which 1 is a mold placing plate, 2 is a pressure receiving plate, and is connected to four corner tie bars 3 and 3 on a machine base 4. . Reference numeral 5 denotes a movable plate that is inserted through the tie bars 3 and 3 so as to be movable forward and backward with respect to the mold placing plate 1 and functions as a mold clamping plate. , 61, 61 and 61 are provided to connect the toggle links 61, 61 to the upper and lower positions of the pressure receiving plate 2 and the movable platen 5, respectively.

  At the center of the pressure receiving plate 2, a toggle driving screw shaft 62 located in the center between the toggle links is rotatably inserted horizontally and supported, and the toggle links 61, 61 are attached to the screw shaft 62. A cross head 64 that bends and extends through the operating links 63 and 63 is screwed so as to move forward and backward by the rotation of the screw shaft 62 by an electric servo motor (not shown).

  The movable platen 5 has a rotating plate 12 with a gear wheel on the surface facing the mold placement platen 1, and a rotation support device 13 for the rotating plate 12 is provided at the center. The turntable 12 is moved forward and backward together with the movable platen 5 by the bending / extending operation of the toggle mechanism 6, whereby two sets of molds 7 and 7, a movable die 7 a attached to the left and right symmetrical positions on the front surface of the turntable 12, and The movable mold 7a is positioned at the same position so that the mold can be opened / closed and clamped with two sets of fixed molds 7b attached to the left and right sides of the surface of the mold table 1. Further, both lower sides of the movable platen 5 are slidably supported by a guide mechanism 9 on a machine base 4 provided with a height adjusting member 8, thereby maintaining parallelism.

The abutment of the surface of the movable platen 5 and the rotary platen 12 is performed by flat convex surfaces 10 and 10 partially projecting from the front surface of the movable platen 5 (on the mold platen side). The contact surface is formed on a surface corresponding to the plurality of mold attachment surfaces 11 and 11 set at a symmetrical position on the front surface (on the mold placement plate side) of the rotating disk 12 with substantially the same area as the mold attachment surface 11. Is limited contact between the rotating disk 12 and the movable platen 5 by the contact surface by the convex 10, 10, the opposing surface of the rotating disk 12 and the movable platen 5 is other than the abutting surfaces are separated.

  When the toggle mechanism 6 is extended and operated in such a state, the clamping force by the toggle links 61 and 61 at the upper and lower positions of the movable platen 5 is transmitted only from the convex surfaces 10 and 10 to the rotary platen 12, and a certain amount of force is applied to the movable platen 5. Even if the bending occurs, the influence of the bending does not reach the rotating disk 12. Therefore, even if the rotating disk 12 is interposed, the mold clamping force by the toggle links 61, 61 in the upper and lower positions causes the mold mounting surface 11, 11 will be concentrated. This eliminates the tendency of the molds to easily open outward when the two sets of symmetric molds 7 and 7 are clamped, and the two sets of molds 7 and 7 are simultaneously clamped with a uniform clamping force. be able to. This is also applicable to molding of a molded product using two sets of dies having different projected areas.

It is a principal part vertical side view of the toggle type | mold clamping apparatus of the injection molding machine concerning this invention. It is a top view of the principal part same as the above. It is a front view by the side of the turntable of a movable board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Type mounting board 2 Pressure receiving board 3 Tie bar 5 Movable board 6 Toggle mechanism 61 Toggle link 7 Mold 9 Guide mechanism 10 Convex surface (contact surface)
11 type mounting surface 12 turntable

Claims (1)

A mold platen and a pressure plate are connected by a tie bar, a movable plate that is inserted through the tie bar so as to be movable forward and backward with respect to the mold platen, and a rotary plate provided on a surface of the movable plate facing the mold platen, In the toggle type clamping device, which consists of a toggle mechanism that is provided between the pressure plates and the movable plate by connecting a toggle link between the two plates, and in which a plurality of dies are attached to the symmetrical position of the rotating plate.
The abutment surface of the movable platen and the rotating plate is limited to the corresponding surface with the multiple mold mounting surfaces set at the symmetrical position of the rotating plate, and the mold clamping force by the toggle link in the vertical position is evenly applied to the multiple molds A toggle type mold clamping device for an injection molding machine, wherein

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