JPS644894B2 - - 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 absolutely essential 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 the mold clamping force and control the mold clamping stroke. This is a necessary element to facilitate changes.
If this could be incorporated into the four components mentioned 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 fixed plate 11 to which a fixed mold (not shown) is fixed in FIG.
A tie bar 14 (two shown in the figure, but there are actually four) having a plurality of grooves or screws 14A passes through approximately half of the movable plate side (left side in the figure), and a wedge 15 is inserted into the lower surface of the tie bar 14. The attached sliding plate 16 slides on the upper surface of the sliding surface 17 attached to the upper surface of the bed 12, so that the movable plate 13 moves.

As shown in FIG. 2, a piston A18 is fixed to one end of the tie bar 14 on the fixed plate side (the right end in the figure), and the piston A18 is a mold clamping member provided in the fixed plate 11 and having a mold clamping chamber 19A and an open chamber 19B. It is adapted to slide within the cylinder 19, and the end of the tie bar 14 on the side opposite to the piston A is supported by the movable plate 13 by a bush 20 provided on the movable plate 13. Note that the cylinder head of the mold clamping cylinder 19 is covered by a lid 21. Further, a hole 22 is formed in approximately half of the tie bar 14 from the end opposite to the piston, into which one end is inserted so as to be movable forward and backward without contacting the inner surface of the hole 22 of the tie bar 14. The other end is a stopper 2 with multi-stage grooves for adjusting the mold clamping stroke.
4 is attached to the shaft 23. Stroke bar 2
4 is adapted to engage with a hole at the left end of the connect barrel 25 fixed to the movable plate 13 via slide plates 26A and 26B and split collars 27A and 27B, which are split into two parts, as shown in FIG. . The connect barrel 25 has one open end connected to the movable plate 1.
It is a cylindrical body with a bottom that is mounted in a cantilever state on the anti-mold mounting surface of No. 3, and a hole 25B is provided at the bottom of the other end through which the stopper 24 of the shaft 23 passes, and a split hole is provided near the bottom. Hole 25A for inserting collar 27A
is open. Further, a half nut cylinder 28 is fixed to the left side of the movable plate 13, and the cylinder 28 is connected to the plurality of grooves of the tie bar 14 or the screws 1.
A half nut 30 is connected to the half nut 30, which is divided into two parts at the same pitch as 4A, and which cannot be moved in the left-right direction in FIG. The movable plate 13 is configured to be integrated with the tie bar 14 by a half nut 30.

As shown in FIG. 1, a relatively small diameter boost cylinder 31 is attached to the movable plate 13, and a piston B32 within the boost cylinder 31 is connected to the fixed plate 11 via a piston rod 32A. In addition, since the piston A18 of the tie bar 14 generates mold clamping force, four tie bars 14 are used.
However, the boost cylinder 31 only needs to generate the force necessary to slide the movable plate 13, the connect barrel 25, the stop 24, and the tie bar 18, so two to four boost cylinders are required. They are provided accordingly.

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 1
3 is connected to the shaft 23 via a connect barrel 25 and a stop bar 24. The solid line on the movable plate 13 is the backward limit position X. In this state, when pressure oil is supplied to the right through hole 31B of the boost cylinder 31, the movable plate 13 moves to the right. Note that when the movable plate 13 moves forward, the half nut 30 is in an open state. Moving plate 13
As the forward movement progresses and the stroke Lmax is moved, axis 2
3 collides with the innermost end of the hole 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 from the cylinder 28 and engaged with the tie bar 14. Subsequently, when pressure oil is supplied to the mold clamping chamber 19A of the mold clamping cylinder 19, the movable plate 13 further advances to position Z.
(Move to the right in the diagram). , the fixed mold and the movable mold are brought together and a predetermined mold clamping force is generated.

Figure 4 shows the split collar 27B on the stop bar 24.
When the device is installed in the groove at the rear end (leftmost in the figure),
In this case, the mold clamping stroke of the movable plate 13 is the minimum, and both the fixed and movable 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 through hole 31B on the right side of the boost cylinder 31 to move the movable plate 13 to the right to the position shown in FIG. (When in the intermediate position between Fig. 2 and Fig. 4, press the boost cylinder 3 to the desired position.)
1 to move the movable plate 13 to the right) Then, when the split collars 27A and 27B are attached to the stop bar 24, the adjustment of the mold clamping stroke is completed. Fourth
In the figure, the mold clamping stroke is at its minimum, and the movable plate 13 is moved to the right by the boost cylinder 31 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 left side through hole 31A of the boost cylinder 31 is different among the operations described above, and the other operations are the same, so a description thereof will be omitted.

When the movable plate 13 is at position Z in Fig. 2 and in the mold clamping state, an injection mechanism (not shown) fills the cavity made up of both fixed and movable plate molds with resin, and when the resin is solidified, the mold clamps. cylinder 19
When pressure oil is removed from the mold clamping chamber 19A and pressure oil is supplied to the opening chamber 19B, the tie bar 14 moves to the left in the figure. At this time, the half nut 30 is engaged with the tie bar 14, so the movable plate 13 moves to the second From position Z to position Y in the diagram
Go backwards until. (Go left in the diagram). At this point, the supply of pressure oil to the open chamber 19B is stopped and the half nut 3
0 and then supply pressure oil to the left side through hole 31A of the boost cylinder 31, the movable plate 13 retreats and returns to position X. If the pressure oil supply to the boost cylinder 31 is stopped when the position X is reached, the movable plate 1
3 is stopped and one cycle is completed.

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 shaft sliding in the hole of the tie bar via the stop bar and the split collar. , the mold clamping stroke was adjusted, so the connecting plate of the conventional example was 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]

Each of the figures shows an embodiment of the present invention; FIG. 1 is a side view of the entire mold clamping device, FIG. 2 is a partial vertical sectional view, and FIG. 3 is an enlarged sectional view of a portion of FIG. 2. , FIG. 4 is a longitudinal sectional view with some parts omitted during an operation different from FIG. 2. 11... Fixed plate, 13... Moving plate, 14... Tie bar, 14A... Groove or screw, 18... Piston A, 19... Mold clamping cylinder, 22... Hole, 2
3...Shaft, 23A...Piston rod, 24...
Stop bar, 25...Connect barrel, 27
A, 27B... split collar, 30... half nut, 31... boost cylinder.

Claims (1)

[Claims] 1. A fixed plate supporting a fixed mold and forming a mold clamping cylinder, a movable plate to which a movable mold is attached, one end of which is formed into a piston A that slides inside the mold clamping cylinder, and a piston A that slides in the mold clamping cylinder from approximately the center. A plurality of grooves or screws are provided on the opposite outer periphery of the piston A to engage with a half nut described later, and the piston A
A tie bar having a hole formed from the opposite end surface toward the center thereof, and a tie bar provided on the opposite mold mounting surface of the movable plate, and engaged with the groove or screw of the tie bar from the outer peripheral surface of the tie bar at the mold clamping limit. A half nut divided into two parts, a shaft whose one end is movably inserted into an internal hole provided in the tie bar, and whose opposite end of the tie bar hole is a stopper with multi-stage grooves for adjusting the mold clamping stroke, and an opening. It is a bottomed cylindrical body whose one end is cantilevered on the opposite mold mounting surface of the movable plate, and the bottom has a hole through which the stopper passes, and the side near the bottom has a hole for inserting a split collar, which will be described later. A mold clamp for an injection molding machine comprising a connect barrel provided with a hole, and a split collar for adjusting the mold stroke that engages a groove of the stopper from the circumferential direction so as to sandwich the bottom inside and outside the bottom of the connect barrel. Device.