JP2010228429A - Fixed platen for injection molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixed platen used for an injection molding machine, preventing the inclination of a die mounting surface caused by nozzle touch force in a nozzle touch time and preventing the deformation of the die mounting surface caused by the reaction of mold clamping force received from a tie bar. <P>SOLUTION: The fixed platen for the injection molding machine is provided with: a tie bar connecting part 11 having a through-hole for the tie bar 2 to penetrate and a through-hole for a nozzle 7 of an injection apparatus to penetrate; and a die mounting part 10 having the die mounting surface 6 to which a fixed side die 4 is mounted, and a through-hole for the nozzle 7 to penetrate. The tie bar 2 is fixed to the tie bar connecting part 11, and the tie bar connecting part 11 is fixed to a base. The die mounting part 10 is slidably guided along the axial direction of the tie bar 2, and the tie bar connecting part 11 is rotatably connected to the die mounting part 10 around an axis arranged in parallel with a die surface on a horizontal plane passing through the center of the injection nozzle. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an injection molding machine that manufactures a molded product by injecting a molten raw material between a pair of molds, and more particularly to a stationary platen used in the injection molding machine.

  As an injection molding machine for manufacturing a molded product, Patent Document 1 includes a fixed platen and a movable platen provided on a base, a mold clamping mechanism is provided on a support element to drive the movable platen, and force transmission during mold clamping is performed. A technique of an injection molding machine provided with a U-shaped member as an element is disclosed.

  Further, in Patent Document 2, the shaft center passes through the central axis of the fixed platen, and is fixed through an axis parallel to the mold mounting surface of the fixed platen and parallel to the base surface of the injection molding machine. A technique is disclosed in which the platen is supported from both sides to prevent the stationary platen from falling when touching the nozzle, and to prevent the asymmetrical deformation of the stationary platen during mold clamping.

  In Patent Document 3, a support member that is coupled to the vicinity of both sides of the nozzle insertion hole on the side opposite to the die mounting surface of the fixed platen and has a lower end fixed to the base of the injection molding machine is used. A technique for preventing a fall is disclosed.

  In Patent Document 4, a support that rotatably supports a fixed platen is fixed to the base of an injection molding machine, and the bearing portion of the fixed platen is sufficiently separated from the portion that fixes the tie bar, so that the axial deformation of the tie bar is prevented. A technique for supporting a fixed platen that is free and uniformly applies a clamping force to the entire surface of the mold is disclosed.

  Patent Literature 5 and Patent Literature 6 disclose a mold clamping device of an injection molding machine. In this mold clamping device, a fixed platen is connected to a tie bar connecting portion and a mold in order to eliminate a shortage of mold clamping force due to deformation of the platen. A structure is disclosed that is divided into an attachment portion and integrally joined at the center.

JP-A-7-68612 JP 2001-239561 A JP 2008-238769 A Japanese Patent Application Laid-Open No. 2000-301569 JP-A-8-258103 Utility Model Registration No. 2587035

  A mold clamping device of an injection molding machine includes a fixed platen 31 installed on a base, a plurality of tie bars 2 fixed at corners thereof, a movable platen 3 movably installed along the tie bars 2, and a mechanism for driving the movable platen 3. It consists of and. Then, the fixed mold 4 and the movable mold 5 are installed on the opposing surfaces of the fixed platen 31 and the movable platen 3, and the mold of the mold is moved forward and backward with respect to the fixed platen 31. Open and close (see FIG. 6).

  When the nozzle 7 of the cylinder for injection is pressed against the fixed mold 4, the fixed platen 31 is tilted, and the fixed mold 4 attached to the fixed platen 31 is also tilted. 33 is displaced. Therefore, there is a problem that the mold guide pins 32 are worn when the mold is opened and closed repeatedly.

  The fixed platen 31 has a structure in which a corner portion is supported by the tie bar 2 and receives a clamping force from the fixed mold 4 at the central portion. Therefore, when a mold clamping force is applied to the mold, the mold mounting surface 6 of the fixed platen 31 is deformed into a concave bowl shape with respect to the fixed mold 4 due to the bending moment. If it does so, since a contact surface pressure will fall in a metal mold | die center part, there exists a problem which a burr | flash generate | occur | produces in the molded product near the metal mold | die center part.

  In the technique of the injection molding machine disclosed in Patent Document 1 described in the background art, since the stationary platen on the mold mounting side is fixed to the base, the stationary platen falls when receiving the nozzle touch force. There's a problem. The technique of the injection molding machine disclosed in Patent Literature 2 can prevent the fixed platen from tilting due to the nozzle touch force, but cannot prevent the mold mounting surface from being deformed by the clamping force (FIG. 7 of Patent Literature 2). reference). The technique disclosed in Patent Document 3 prevents the fixed platen from falling when the nozzle is touched, and does not attempt to prevent deformation of the mold mounting surface. In the technique disclosed in Patent Document 4, the tie bar fixing portion and the bearing portion of the support shaft are arranged in the peripheral portion of the fixed platen, and it is difficult to prevent the mold mounting surface from being deformed into a bowl shape. . Further, in the mold clamping devices disclosed in Patent Document 5 and Patent Document 6, since the tie bar connecting portion and the mold attaching portion are integrally configured, at the time of nozzle touch, the tie bar connecting portion and the mold attaching portion are Can not prevent the fixed platen from falling down.

  Accordingly, an object of the present invention has been made in view of the above circumstances, and at the same time, the mold mounting surface is prevented from being inclined by the nozzle touch force at the time of nozzle touch, and at the same time, the mold is mounted by the reaction force of the mold clamping force received from the tie bar. It is an object of the present invention to provide a stationary platen used for an injection molding machine capable of preventing surface deformation.

  In the invention according to claim 1 of the present application, a tie bar connecting portion having a first through hole through which a tie bar passes and a second through hole through which a barrel of an injection cylinder of an injection device passes, and a fixed side mold are attached. A mold mounting portion having a third through hole through which the mold surface and the tie bar pass and a fourth through hole through which the nozzle of the injection device passes, and the mold mounting portion is formed in the third through hole. The tie bar is passed through and is guided by the base of the tie bar or the injection molding machine so as to be slidable along the axial direction of the tie bar, and the tie bar is fixed to the tie bar connecting part. Fixed to the base, and the tie bar connecting portion is rotatably connected to the mold mounting portion around an axis arranged in parallel with the mold surface on a horizontal plane passing through the nozzle center of the injection device. A fixed platen of an injection molding machine according to symptoms.

  According to the present invention, an injection molding machine capable of preventing the mold mounting surface from being inclined by the reaction force of the mold clamping force received from the tie bar while preventing the mold mounting surface from being inclined due to the nozzle touch force at the time of nozzle touch. The stationary platen used can be provided.

It is a schematic block diagram of the injection molding machine provided with embodiment of the stationary platen of this invention. It is an external appearance perspective view of the metal mold | die attaching part and tie bar connection part which comprise embodiment of the stationary platen of this invention. It is sectional drawing of embodiment of the stationary platen of this invention. It is a figure explaining a deformation | transformation when nozzle touch force is added to embodiment of the stationary platen of this invention. It is a figure explaining the deformation | transformation of the tie bar connection part of a stationary platen when the mold clamping force acts on embodiment of the stationary platen of this invention. It is a figure explaining deformation | transformation of a stationary platen when a nozzle touch force acts on the stationary platen of a prior art. It is a figure explaining deformation | transformation of a stationary platen when a clamping force acts on the stationary platen of a prior art.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is demonstrated about the component which is the same as that of a prior art, or similar.
FIG. 1 is a schematic view of an injection molding machine using an embodiment of a fixed platen of the present invention. The injection molding machine includes an injection device Mi and a mold clamping device Mc on a base 9. The mold clamping device Mc is installed so as to be movable along a fixed platen 1 installed on the base 9, a plurality of (four in this specification) tie bars 2 fixed to a corner portion of the fixed platen 1, and the tie bars 2. The movable platen 3 and a toggle mechanism for driving the movable platen 3 are provided. A fixed mold 4 and a movable mold 5 are attached to the opposing surfaces of the fixed platen 1 and the movable platen 3, respectively. The molds 4 and 5 are opened and closed by moving the movable platen 3 forward and backward toward the fixed platen 1 side. As will be described with reference to FIG. 2, the fixed platen 1 includes a mold attachment portion 10 and a tie bar connecting portion 11.

  As shown in FIG. 2, the fixed platen 1 includes a mold attachment portion 10 and a tie bar connection portion 11. The mold attaching part 10 is arranged in parallel to the movable platen 3 side of the tie bar connecting part 11, and through holes 21 into which the tie bars 2 are inserted are provided at the four corners. A bush 17 is press-fitted into each through-hole 21 in order to allow the mold mounting portion 10 to slide with respect to the tie bar 2. A through hole 22 is provided in the center portion of the mold mounting portion 10 so that the tip of the nozzle 7 can be pressed against the stationary mold 4.

  Furthermore, two flat mountain-shaped protrusions projecting toward the tie bar connecting portion 11 are formed on the surface of the mold attaching portion 10 on the side facing the tie bar connecting portion 11 when the die attaching portion 10 is assembled to the mold clamping device Mc. A coupling portion 12 is provided. Each coupling portion 12 is provided with a through hole 23 through which the pin 14 passes. A bush 15 is press-fitted into the through-hole 23 so that the coupling portion 12 can rotate with respect to the pin 14. A state of penetrating the pin 14 will be described with reference to FIG.

  The tie bar connecting portion 11 is provided with through holes 18 into which the tie bars 2 are inserted at four corners and through holes 19 into which the barrel 8 of the injection cylinder is inserted at the center thereof. Further, on the surface of the tie bar connecting portion 11 on the movable platen 3 side (surface opposite to the installation portion of the injection device Mi), four flat mountain-shaped coupling portions 13 protruding toward the movable platen 3 are provided. Yes. Each coupling portion is provided with a through hole 20 through which the pin 14 (see FIG. 3) passes. In this embodiment, four protruding flat mountain-shaped coupling portions 13 are arranged symmetrically around the through hole 19 two by two. The two coupling portions 13 are provided at intervals so that the coupling portion 12 of the mold attachment portion 10 fits between the two coupling portions 13.

  FIG. 3 is a cross-sectional view of the fixed platen 1 taken along the arrow AA shown in FIG. The fixed platen 1 is configured by connecting a mold attaching portion 10 and a tie bar connecting portion 11 to connecting portions 12 and 13 by pins 14. A bush 15 is press-fitted into the through hole 23 of the coupling portion 12. The pin 14 is arranged in parallel to the mold surface and on a horizontal plane including the central axis of the barrel 8. The pin 14 is inserted into the through hole 20 provided in the tie bar connecting portion 11 and is inserted into the through hole 23 provided in the mold attaching portion 10. The pin 14 is bolted to the tie bar connecting portion 11 or is press-fitted into the through hole 20, and the pin 14 and the tie bar connecting portion 11 do not rotate relative to each other. On the other hand, since the bush 15 is press-fitted into the through-hole 23 provided in the mold attaching part 10, the pin 14 and the bush 15 can slide relative to each other around the axis of the pin 14. Therefore, the mold attaching part 10 and the tie bar connecting part 11 are configured to be swingable around the center of the pin 14. When the mold clamping force does not act on the mold and the nozzle 7 is not pressed, the mold attaching portion 10 and the tie bar connecting portion 11 of the fixed platen 1 are in a parallel state.

  FIG. 4 is a diagram for explaining deformation when a nozzle touch force is applied to the embodiment of the fixed platen of the present invention. As shown in FIGS. 1, 4, and 5, the tie bar connecting portion 11 is directly fixed to the base 9. The mold mounting portion 10 is guided by the tie bar 2 via the bush 17 so that the mold mounting surface 6 does not tilt with respect to the vertical direction. As another embodiment, it may be guided by the base 9 through a linear guide (not shown). Note that a guide hole 33 is provided in the fixed mold 4 (not shown). The movable die 5 is provided with guide pins 32 (not shown).

The tie bar connecting portion 11 is directly fixed to the base 9, and the portion of the tie bar connecting portion 11 fixed to the base 9 and the portion receiving the nozzle touch force are separated in the vertical direction. When the touch force is received, the tie bar connecting portion 11 receives a moment and tilts with respect to the vertical direction.
On the other hand, as described with reference to FIGS. 2 and 3, the mold attachment portion 10 is rotatable because the coupling portion 16 that is a connection portion between the mold attachment portion 10 and the tie bar connection portion 11 is rotatable. A moment acting on the tie bar connecting portion 11 does not act on the mold attaching portion 10. Therefore, even if a nozzle touch force acts on the tie bar connecting portion 11, the mold attaching portion 10 does not tilt with respect to the vertical direction.

  FIG. 5 is a view for explaining deformation of the tie bar connecting portion of the fixed platen when a mold clamping force is applied to the embodiment of the fixed platen of the present invention. When a mold clamping force acts on a mold composed of the fixed mold 4 and the movable mold 5, the reaction force of the mold clamping force is transmitted from the mold mounting portion 10 to the tie bar connecting portion 11 through the coupling portion 16. . Although the tie bar connecting portion 11 is deformed into a bowl shape by a bending moment, the coupling portion 16 is disposed at the center portion of the mold attaching portion 10 and the tie bar connecting portion 11 and has a structure that receives the reaction force of mold clamping at the center. No bending moment is applied to the mold mounting portion 10 and it does not deform.

  As described with reference to FIGS. 4 and 5, the fixed platen of the present invention prevents the mold mounting surface from being inclined due to the nozzle touch force at the time of nozzle touch, and at the same time, due to the reaction force of the mold clamping force received from the tie bar. It is possible to provide a stationary platen used in an injection molding machine that can prevent deformation of a mold mounting surface.

DESCRIPTION OF SYMBOLS 1 Fixed platen 2 Tie bar 3 Movable platen 4 Fixed side metal mold 5 Movable side metal mold 6 Mold attachment surface 7 Nozzle 8 Barrel 9 Base 10 Mold attachment part 11 Tie bar connection part 12 Connection part 13 Connection part 14 Pin 15 Bush 16 Connection Part 17 Bush 18 Through-hole 19 Through-hole 20 Through-hole 21 Through-hole 22 Through-hole 23 Through-hole 31 Fixed platen 32 Guide pin 33 Guide hole

Claims (1)

A tie bar connecting portion having a first through hole through which the tie bar passes and a second through hole through which the barrel of the injection cylinder of the injection device passes;
A mold mounting portion having a mold surface to which the fixed-side mold is mounted, a third through hole through which the tie bar passes, and a fourth through hole through which the nozzle of the injection device passes,
The mold attaching portion is guided by the base of the tie bar or the injection molding machine so that the tie bar passes through the third through hole and is slidable along the axial direction of the tie bar.
The tie bar is fixed to the tie bar connecting portion, the tie bar connecting portion is fixed to a base of an injection molding machine,
The injection molding characterized in that the tie bar connecting portion is rotatably connected to the mold mounting portion around an axis arranged in parallel to the mold surface on a horizontal plane passing through the nozzle center of the injection device. Fixed platen of the machine.

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