JPH0124617B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a composite mold clamping device for an injection molding machine used for molding synthetic resin.

(Prior art) A complex type mold clamping device called a toggle direct pressure type has a structure in which a movable platen and a ram of a mold clamping cylinder are connected by a link toggle, and the mold is opened and closed by the expansion and contraction of the link toggle. Furthermore, mold clamping can be performed by applying pressure to the extended link toggle using a ram.

(Problems to be Solved by the Invention) In general, the above-mentioned composite type mold clamping device can shorten the stroke of the mold clamping cylinder compared to the conventional direct pressure type, and as a result, the mold clamping cylinder can be made smaller. At the same time, it eliminates the need for expensive large pumps.
It is necessary to be able to accurately control the mold clamping force, and with a toggle type, the mold closing position must be set accurately so that a large mold clamping force is generated at the moment the link is fully extended, but with a compound type, the toggle mechanism is Since it is only used to open and close the mold, and there is no need to generate mold clamping force, there is no need to particularly consider the mold closing position, and since no large force is applied when opening and closing the mold, there is no wear on the connecting pins. It has many advantages, including less.

However, since it uses two types, direct pressure and toggle, devices and control means are required to drive the mold clamping cylinder and toggle mechanism, respectively, resulting in higher costs than direct pressure or toggle types. There was a drawback.

(Means for Solving the Problems) This invention was devised to solve the above-mentioned conventional problems, and its purpose is to open and close molds by using one drive source. An object of the present invention is to provide an extremely economical composite type mold clamping device that can perform mold clamping.

According to the present invention, a receiving plate is movably provided on a tie bar provided on a pair of fixed plates together with a movable plate, the receiving plate and the movable plate are connected by a link toggle, and the receiving plate is retracted on the tie bar. A member for regulating the position and a spring member for always pressing the receiver backward are provided, and an arm for expanding and contracting the link toggle is provided between the eccentric position of the link toggle and the operating member of the drive device behind the receiver. The gist of this is that

(Function) In the above configuration, when the ram is pressurized in the forward direction in the mold open state, the pressure is transmitted to the link toggle via the telescopic arm. Both ends of the link toggle are connected to a receiving plate and a movable plate whose retreating position is regulated, and since the connecting part of the arm is in an eccentric position, the link toggle shortened in the bent state will not operate in the extending direction. , move the movable platen in the mold closing direction.

Even when the link toggle is extended, the ram is still pressurized in the forward direction. Due to the pressure, the receiving plate moves forward together with the link toggle against the spring member, presses the movable plate to close the mold, and then moves on to mold clamping.

When the ram is pressurized in the backward direction in the mold-closed state, the receiving plate is first pulled back to the regulating position by the arm together with the link toggle. The link toggle is then pulled and folded outward from the central joint to shorten it. Due to this shortening, the movable platen is also pulled back and the mold is opened.

This will be explained in detail using an illustrated example.

(Example) In the figure, 1 and 2 are fixed plates, and 3 is a movable plate. The stationary plates 1 and 2 are installed on a machine stand (not shown) with a required interval, and both are connected by four tie bars 4, 4. The movable platen 3 and the receiving platen 5 are inserted through the tie bars 4, 4 so as to be able to move forward and backward.
is installed.

The receiving plate 5 is provided close to the other stationary plate 2 provided with the drive device 7. Further, both ends of the receiving plate 5 are inserted onto the tie bar between the regulating members 8, 8 formed by flanges provided on the tie bars 4, 4 at a constant interval, and are always connected to the rear side with the spring member 9, that is, to the fixed plate. Oppressed in two directions.

The movable plate 3 and receiving plate 5 are a pair of link toggles 1
0,10, and each link toggle 10,10 is connected via a parallel arm 11,11 to an actuating member 12, or ram, of the drive device 7 consisting of a hydraulic cylinder.

The arms 11, 11 are connected by pins to a mounting plate 13 provided at the end of the actuating member 12 and to an eccentric position outside the link 10a, so that the actuating member 12 is pressurized in the forward direction. When pressed, the link toggles 10, 10 are pressed, and when pressed in the backward direction, they are pulled back. Note 1
4 is a toggle stopper, and 15 is a connecting portion on the movable plate side.

Next, the mold opening/closing and mold clamping operations will be explained.

In the mold open state shown in FIG.
When pressure oil is supplied to the rear chamber 7a, the actuating member 12 moves forward and presses the arms 11, 11. The pressing force is applied to the link 10 via the connecting pin at the end of the arm.
a, 10a, and is also transmitted to the receiving plate 5. However, since the receiving plate 5 is pressed backward by the spring member 9, it is difficult to move, so the pressing force acts strongly on the link toggle side, and the link 10a rotates inward using the connecting pin with the receiving plate 5 as a fulcrum. .

Further, since the movable platen 3 connected to the link 10b is in a free state, the link 10b is pushed and extended by the rotational force of the link 10a, and the movable platen 3 moves forward.

The rotation of the link 10a is stopped when the link 10a contacts the stopper 14. In addition, at the stop position, as shown in Fig. 2, the arm 1
1, 11 and link toggles 10, 10 are immediately extended, and the movable platen 3 reaches a position where a predetermined gap is left between the molds 6.

Link toggles 10, 10 and arms 11, 11
When both extend, the pressing force transmitted to the link 10a acts on the receiving plate 5 via the connecting pin.
The receiving plate 5 resists the spring member 9 and the link toggle 10,
10 and the movable platen 3, and as shown in FIG. 3, after the mold 6 is closed, more forceful pressure is applied to bring the mold into a clamped state.

In the mold clamping state, the front chamber 7b of the pressurizing device 7
When hydraulic pressure is supplied to move the movable member 12 backward, the receiving plate 5, together with the link toggles 10, 10, is moved back by the arms 11, 11 to a position where it contacts the regulating member 8 and stops. As a result, the movable platen 3 also moves backward, and a strong mold opening occurs there.

When the movable member 12 moves further, the link 10a
is pulled by arm 11 and rotates outward.
As a result, the link 10b bends outward from the central connecting part using the connecting pin on the movable platen side as a fulcrum and shortens, and the movable platen 3 also retreats, causing mold opening there, as shown in FIG. The state shown is shown.

Therefore, one pressurizing device 7 can successively perform mold opening or mold closing and mold clamping. Also, the mold opens and closes at high speed because it uses a toggle.

FIG. 4 shows an example in which a mold thickness adjustment device 20 is provided on the side of the movable platen 3, in which a rotatable nut member 21 is provided inside the movable platen 3, and a rotatable nut member 21 is provided at the tips of the link toggles 10, 10. A mold thickness adjustment screw 22 is provided, the two are screwed together, and the nut member 2 is screwed together.
By rotating the movable plate 1 from the outside manually or by an electric motor, hydraulic motor, etc., the movable plate 3 is moved back and forth and changed to a position commensurate with the mold thickness.

FIG. 5 shows a case where the tie bar 4 is provided with a mold thickness adjustment device 30, in which a threaded portion 31 is formed at the rear of the tie bar 4 according to the mold thickness adjustment distance, and is screwed into the threaded portion 31 at the rear. , is rotatable with respect to the movable fixed plate 2, and has a sprocket part 32 on the outer periphery.
A cylindrical rotating member 33 is provided in the front part through which the receiving plate 5 is inserted, and has the regulating members 8, 8 and the spring member 9 at the front and rear parts of the receiving plate 5, and each sprocket 32 is connected to a chain. 34, and a sprocket 36 integrated with the output shaft of a motor 35 is connected to the chain 34, and the rotation of the motor 35 drives the chain 34 and rotates the rotating member 33 in synchronization. The position of the rotating member 33 can be changed, and at the same time, the driving device 7 and receiving plate 5 of the fixed platen 2 connected to the rotating member 33 are relatively moved on the tie bar 4 to change the position of the movable platen 3. However, this allows the mold thickness to be adjusted.

FIG. 6 shows an example of a drive device in which a servo motor 50, a screw shaft 51, and a nut member 52 convert rotational motion into linear motion instead of a hydraulic cylinder.

In this case, a screw shaft 51 that is rotated by the drive of a servo motor 50 is provided between the fixed platen 2 and the receiving plate 5, and has a nut member 52 in the center that is threadedly engaged with the screw shaft 51, and is guided by the tie bar 4. An actuation plate 53 is provided, which is moved backward by the arms 11, 11.
are connected by pins.

Then, the servo motor 50 is operated and the screw shaft 5 is
1, the operating plate 53 moves forward and backward, exhibiting the same effect as the ram of the hydraulic cylinder.

In this case, in order to allow the receiving plate 5 to move forward during strong mold clamping, a gap is provided between the tip of the screw shaft 51 and the receiving plate 5, and a spring 54 is disposed therein.

(Effects of the Invention) As described above, the present invention provides a receiving plate between the movable platen and the drive device, connects the receiving plate and the movable plate by a link toggle, and operates the link toggle and the drive device. An arm was provided across the member, and the arm enabled the link toggle to extend and contract, and a spring member was used to constantly press the receiving plate backwards so that it moved forward and backward only when the link toggle was extended. Equipped with a tightening drive device,
High-speed opening/closing using link toggles is also possible.

Therefore, the toggle drive device and its control device in the conventional toggle direct pressure type can be omitted. In addition, since it is only necessary to interpose a receiving plate between the movable platen and the drive device, it is not particularly complicated compared to conventional systems, and not only can the cost of the device be reduced, but the drive device is also hydraulic. It has the advantage that it can be applied not only to electric vehicles but also to electric vehicles.

[Brief explanation of drawings]

The drawings show a partially longitudinal section of an embodiment of the composite mold clamping device according to the present invention, in which Fig. 1 is a side view when the mold is opened, Fig. 2 is a side view when the mold is closed, and Fig. 3 is a side view when the mold is closed. The figure is a side view when the mold is clamped, Figures 4 and 5 are side views when the mold is closed of an embodiment having a mold thickness adjustment device, and Figure 6 is a side view when the mold is closed.
The figure is a side view of an embodiment equipped with an electric drive device when the mold is opened and closed. 1, 2... fixed plate, 3... movable plate, 4... tie bar, 5... receiving plate, 7... drive device, 8... regulating member, 9... spring member, 10... link toggle,
10a, 10b...Link, 11...Arm, 1
2... Operating member.

Claims (1)

[Claims] 1. A receiving plate is movably provided together with a movable plate on a tie bar provided on a pair of fixed plates, and the receiving plate and the movable plate are connected by a link toggle, and the receiving plate is retracted on the tie bar. A member that regulates the position and a spring member that always presses the receiver backward are provided, and an arm for expanding and contracting the link toggle is provided between the eccentric position of the link toggle and the operating member of the drive device behind the receiver. A composite mold clamping device characterized by: 2. The composite mold clamping device according to claim 1, wherein the drive device comprises a hydraulic cylinder and a ram. 3. The composite mold clamping device according to claim 1, wherein the driving device comprises a screw shaft rotated by an electric motor, and a plate-shaped movable member that moves forward and backward by the screw shaft using a tie bar as a guide member.