JPS6349607B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold clamping device for an injection molding machine, and particularly to a mold clamping device with a simplified mechanism and a reduced installation area.

Various types of mold clamping devices have been proposed for injection molding machines. Typical examples include direct pressure, toggle, and composite mold clamping systems. A typical example of composite mold clamping systems is the direct lock system. .
The important components that these mold clamping devices have in common are: firstly, a fixed plate for attaching a fixed mold; second, a movable plate for attaching a movable mold; and thirdly, a clamping force loop for transmitting mold clamping force. Fourthly, there is a tie bar to be formed and a mold clamping cylinder. In addition, a ring housing is required for the toggle type, and a connecting plate is required for the direct lock type.

The indispensable components of the mold clamping device of an injection molding machine are a fixed plate, a movable plate, a tie bar, and a mold clamping cylinder.The ring housing and connecting plate form a loop for mold clamping force and This is a necessary element to easily change the tightening stroke, and if this could be incorporated into the four components described above, the mechanism would be simplified.

The present invention has been made from this point of view, and its purpose is to simplify the mechanism and reduce the cost of the device by removing the connecting plate in the direct lock system and incorporating this mechanism into the fixed plate, moving plate, and tie bar. Another object of the present invention is to provide a mold clamping device for an injection molding machine with a reduced installation area.

The present invention will be explained below with reference to FIGS. 1 to 4 showing one embodiment.

A fixing plate 11 to which a fixed mold (not shown) is fixed in FIG. 1 is fixed to a bed 12.
The movable plate 13 to which the movable mold (not shown) that faces the fixed mold is fixed has a tie bar 14 (two shown in the figure, but there are actually four) having a plurality of grooves or screws 14A approximately in the left half. The movable plate 13 slides when the sliding plate 16, which is penetrated through the sliding plate 16 and attached to the lower surface thereof via a wedge 15, slides on the upper surface of the sliding surface 17 attached to the upper surface of the bed 12.

At one end of the tie bar 14 (the right end in the figure) there is a second
As shown in the figure, the piston A18 is fixed, and the piston A18 is provided on the fixed plate 11 and is placed in the mold clamping chamber 19A.
The left end of the tie bar 14 is supported on the movable plate 13 by a bush 20 provided on the movable plate 13. Note that the right end of the mold clamping cylinder 19 is covered by a lid 21. Also, approximately inside the left half of the tie bar 14 is a boost cylinder 22.
is formed, and a piston B23 is slidably inserted therein. A stop bar 24 having multi-stage grooves is attached to the left side of the piston B23 to adjust the mold clamping stroke via the piston rod 23A. As shown, it is designed to engage with sliding plates 26A and 26B via split collars 27A and 27B, which are divided into two. In addition, connect barrel 25
A hole 25A for inserting a split collar 27A is provided near the left end of the hole 25A. Further, a half-nut cylinder 28 is fixed to the left side of the movable plate 13, and the cylinder 28 is split into two at the same pitch as the plurality of grooves or screws 14A of the tie bar 14.
In FIG. 2, a half nut 30 is connected that cannot be moved in the left-right direction but is slidable in the vertical direction by a sliding plate 29. The movable plate 13 is configured to be integrated with the tie bar 14 by the half nut 30 when the half nut 30 is closed. The piston A18 of the tie bar 14 is provided on all four tie bars 14 because it generates mold clamping force, but the boost cylinder 22 simply slides between the movable plate 13, tie bar 18, stop bar 24, and connect barrel 25. Since it is sufficient to generate the force necessary to move the tie bar 14, two to four tie bars are provided as necessary.

Next, the operation of the present invention will be explained.

FIG. 2 shows the case where the mold clamping stroke L is maximized and both the fixed and movable mold thicknesses are minimized. In this case, the movable plate 13 is connected to the piston B23 via the connect barrel 25 and the stop bar 24 by attaching the split collar 27A to the rightmost groove of the stop bar 24 and the split collar 27B to the left groove thereof. . The solid line on the movable plate 13 is the backward limit position X. In this state, when pressure oil is supplied to the left through hole 22A of the boost cylinder 22, the piston B23, that is, the movable plate 13 moves to the right, and the piston rod 23A is guided by the pusher 31.
Note that when the movable plate 13 moves forward, the half nut 30 is in an open state. When the moving plate 13 advances and moves by the stroke Lmax, the piston B23 collides with the right end of the boost cylinder 22 and stops. This position is indicated by a dashed line and is designated as position Y. At this point, since the thickness of the sliding plate 29 has been adjusted in advance for the multiple grooves of the tie bar 14 or the pitch of the screws 14A and the screw pitch of the half nut 30, it is possible to close the half nut 30 at position Y. The half nut 30 is closed by the cylinder 28, and the movable plate 13 is engaged with the tie bar 14. Next, the mold clamping chamber 1 of the mold clamping cylinder 19
When pressure oil is supplied to 9A, the movable plate 13 further moves to the right to position Z, and the fixed mold and movable mold are brought together to generate a predetermined mold clamping force.

FIG. 4 shows the split collar 27B installed in the leftmost groove of the stopper 24, in which case the movable plate 1
The mold clamping stroke of No. 3 is the minimum, and indicates when both the fixed and moving mold thicknesses are maximized.

When changing from the state shown in FIG. 2 to the state shown in FIG. 4, that is, the mold clamping stroke is adjusted as follows. First, the split collars 27A and 27B are removed from the stop bar 24, and pressure oil is supplied to the left through hole 22A of the boost cylinder 22 to move the piston B23 to the right to the position shown in FIG. (Figures 2 and 4
If it is at the intermediate position in the figure, move the piston B2 to the desired position.
3 to the right) Next, the split collars 27A and 27B are attached to the stop bar 24, and the adjustment of the mold clamping stroke is completed. In FIG. 4, the mold clamping stroke is at its minimum, and the movable plate 13 is moved to the right by the boost cylinder 22 to the position indicated by the dashed line. When changing from the state shown in FIG. 4 to the state shown in FIG. 2, only the supply of pressure oil to the right through hole 22B of the boost cylinder 22 is different among the operations described above, and the other operations are the same, so a description thereof will be omitted. However, when supplying oil to the through hole 22B of the boost cylinder, if the tie bar 14 moves, the specified stroke cannot be obtained. Therefore, the oil pressure supplied to the through hole 22B must be set to a pressure that does not cause the tie bar 14 to move, or the open cylinder chamber 19B Supply pressure oil to the cylinder chamber 19B, or block the outlet of the open cylinder chamber 19B, and
Do this without moving.

When the movable plate 13 is in the position shown in FIG. 2 and the mold is in a clamped state, an injection mechanism (not shown) fills the cavity made up of both fixed and movable molds with resin, and when the resin is solidified, the mold clamping cylinder 19 If the pressure oil in the mold clamping chamber 19A is removed and pressure oil is supplied to the opening chamber 19B, the tie bar 14 moves to the left and at this time the half nut 30 is engaged with the tie bar 14, so
The moving plate 13 moves leftward from position Z to position Y in FIG. At this point, open Half Nut 30. Subsequently, when pressure oil is supplied to the right side passage hole 22B of the boost cylinder 22, the piston B23 moves to the left, and since the piston B23 is connected to the movable plate 13 via the split collars 26A and 26B and the connect barrel 25, The moving plate 13 moves to the left and returns to position X. Here, when supplying pressure oil to the right side through hole 22B of the boost cylinder 22, it is performed while preventing movement of the tie bar 14 using the same method as when adjusting the mold clamping stroke. If the pressure oil supply to the boost cylinder 22 is stopped when the position X is reached, the movable plate 13
stops and one cycle ends.

As described above, the mold clamping device of the injection molding machine according to the present invention is constructed by fixing the connect barrel to the movable plate and engaging the connect barrel with the piston in the boost cylinder via the split collar, thereby replacing the connecting plate of the conventional example. has been removed. Since the additional components have a simple structure and are relatively small and lightweight, the present invention has the advantage of reducing the weight of the injection molding machine as a whole, thereby reducing costs and installation area.

[Brief explanation of the drawing]

The figures all show one embodiment of the present invention, and Fig. 1 is a side view of the entire mold clamping device, Fig. 2 is a longitudinal sectional view of a part,
FIG. 3 is an enlarged sectional view of a part of FIG. 2, and FIG. 4 is a longitudinal sectional view with a part omitted during an operation different from that in FIG. 11... Fixed plate, 13... Moving plate, 14... Tie bar, 14A... Groove or screw, 18... Piston A,
19...mold clamping cylinder, 22...boost cylinder,
23... Piston B, 23A... Piston rod, 2
4...Stop bar, 25...Connect barrel, 27
A, 27B... split collar, 30... half nut.

Claims (1)

[Claims] 1. A fixed plate that supports a fixed mold and forms a mold clamping cylinder, a movable plate that holds a movable mold and has a half nut slidably attached thereto, and a connect barrel fixed to the opposite side of the fixed plate, and one end. is formed on the piston A that slides within the mold clamping cylinder, and a plurality of grooves or screws are provided from approximately the center to the opposite outer periphery of the piston A to engage with the half nut, and from the opposite end surface of the piston A. A tie bar forming a boost cylinder toward approximately the center, a piston B sliding inside the boost cylinder, a stop bar connected to the piston B via a piston rod and provided with a plurality of grooves, and the stop bar connected to the above. A mold clamping device for an injection molding machine consisting of a split collar for engaging the barrel.