JPH04232716A - Apparatus for driving slide core of mold - Google Patents

Abstract

PURPOSE:To provide a slide core driving apparatus simplified in its structure on the side of a mold and capable of being controlled by the control system of an injection molding machine. CONSTITUTION:The ejection rod 18 of the ejection mechanism 16 in an injection molding machine is provided in a horizontally movable and rotationally drivable manner. The connector 9 engaged with the leading end of the ejection rod 18 and the slide core driving mechanism 10 operated in connection with said connector 9 are provided to a mold. A slide core 6 is driven by rotationally driving the ejection rod 18.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for driving a slide core of a mold with a slide core used in an injection molding machine.

0002

2. Description of the Related Art Molds for molded products with complex shapes, molded products with undercut portions, or molded products with threaded portions are equipped with a slide core or have a split mold structure. Since it is necessary to move the slide core and split mold (hereinafter referred to as slide core) during molding, an angular pin or angular cam is installed in the mold to utilize the movement of the movable mold when the mold is opened. A structure in which a rack and pinion structure is constructed inside the mold and driven by hydraulic pressure, air pressure, or a motor is adopted.

Among these, those with a structure driven by a motor do not have mechanical friction or sliding parts like angular pins, so there is no stress on the mold, and the movable mold is It has the advantage of being able to move the slide core at any time without relying on movement, and there is less concern about contaminating the molding environment unlike with hydraulic or air pressure.

[0004] Conventionally, however, the motor for driving the slide core is installed in a mold, which makes the structure of the mold complicated and expensive. Furthermore, in order to control the movement of the slide core, a control device separate from the control of the injection molding machine is required.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a slide core drive device that has a simple structure on the mold side and can be controlled by the control system of an injection molding machine.

[0006]

Means for Solving the Problems An eject rod in an eject mechanism of an injection molding machine is rotatably supported about its longitudinal axis.

A rotational drive mechanism for the eject rod is provided.

[0008] Thereby, the eject rod is used as an output shaft for rotational driving force.

On the other hand, a mold having a slide core is provided with a connector that obtains rotational driving force through engagement with the eject rod, and a slide core drive mechanism interlocked with the connector.

[0010] When the mold is attached to the platen of the mold clamping part, the structure is such that the eject rod and the connector on the mold side are engaged.

[0011] The drive source of the rotational drive mechanism for the eject rod may be an eject servo motor in the eject mechanism.

0012

[Operation] When the eject rod is driven and rotated, the slide core of the mold is driven through the connector.

[0013] When the drive source of the rotational drive mechanism for the eject rod is an eject servo motor in the eject mechanism, the number of servo motors that need to be controlled in the injection molding machine can be suppressed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a mold clamping section 1 in an injection molding machine, which has a conventional structure including a fixed platen 2 and a moving platen 3. Note that mold clamping mechanisms such as a rear platen, tie bars, and toggles are not shown.

A fixed mold 4a is mounted on the fixed platen 2, and a movable mold 4b is mounted on the moving platen 3. In FIG. 1, the mold is in a clamped state immediately after injection, and a molding cavity 5 formed by fixed-side and movable-side molds 4 (a, b) is filled with resin. Since the molded product formed by the molding cavity 5 described above requires a hole penetrating the side surface (which results in an undercut during molding), the stationary side mold 4a is equipped with a slide core 6 that can move up and down in the figure, and the movable side The mold 4b is equipped with an eject pin 8 that slides in the front-rear direction to eject the molded product and is always biased rearward by a spring 7. Furthermore, mold 4 (a, b
) is equipped with a connector 7 and a slide core drive mechanism 8 for driving this. A rack gear 11 is formed on the side surface of the slide core 6 described above. In addition, each mold 4 for fixed and movable (moving) platens 2 and 3
The attachment mechanisms in (a, b) are not shown.

In this embodiment, the connector 9 is an annular gear rotatably supported on the rear surface of the movable mold 4b, and the shaft portion penetrating in the front-rear direction is formed in a spline fitting hole. .

As shown in the figure, the slide core drive mechanism 10 includes a drive shaft 13 which is driven and rotated via a gear train 12 meshed with the connector 9 on the side of the movable mold 4b, and a fixed mold 4.
It is comprised of a driven shaft 15 that is mounted on the a side and includes a pinion 14 that meshes with the rack gear 11 described above. The driven shaft 15 of the stationary mold 4a projects long rearward, and is spline-fitted to the drive shaft 13 of the movable mold 4b having a corresponding length. This makes it possible to slide the shafts 13, 15 in the longitudinal direction along with the transmission of rotational force and mold clamping/mold opening. These are mold 4 (a
, b) are already in a fitted state before they are attached to each platen 2, 3.

The moving platen 3 is the eject mechanism 1
6, which includes a knockout bar 17, an eject rod 18, a ball screw mechanism 19 arranged symmetrically about the rod 18, and an eject servo motor 20.

The eject rod 18 is arranged in the front-rear direction, and its rear end is pivotally supported by the knockout bar 17 so that it can rotate about a longitudinal axis. The front end of the eject rod 18 extends through the moving platen 3. The front part of the eject rod 18 is formed with a spline up to its tip. Further, the ball nut 21 of the ball screw mechanism 19 is fixedly attached to the rear surface of the knockout bar 17, and is screwed onto the ball nut 21 of the above-mentioned eject rod 1.
A ball screw 22 arranged parallel to the moving platen 8 is rotatably supported by a boss 23 of the moving platen 3 at its front end.

The ejecting servo motor 20 is fixed to the moving platen 3, and a first gear 25 is fixed to its output shaft 24, and an extension shaft 27 is connected to its tip via an electromagnetic clutch 26. A second gear 28 is fixed to the extension shaft 27. The output shaft 24 of the eject servo motor 20 is connected to each ball screw 22 via a first timing belt 30 that is looped from a first gear 25 to a clutch brake 29 attached to each ball screw 22. There is. In addition, the extension shaft 2
Reference numeral 7 denotes a second timing belt 32 that is wound around a second gear 28 and a spline gear 31 that is rotatably supported on the rear surface of the moving platen 3 and that fits into the front spline of the eject rod 18. is connected to.

The clutch brake 29 is a type of electromagnetic brake combined with a clutch, and when activated, the clutch brake 29 is a type of electromagnetic brake that is combined with a clutch.
2 and transmits the rotational force, and when the clutch is not in operation, the clutch is disengaged and rotation relative to the ball screw 22 becomes free, and at the same time, the brake part prevents the ball screw 22 from rotating freely, and is commercially available. . The operation of the clutch brake 29 and the electromagnetic clutch 26 is alternative to each other, so that when one is activated, the other is deactivated.

That is, the knockout bar 17, eject rod 18, first gear 25, clutch brake 29
, the first timing belt 30 and the ball screw mechanism 19
constitutes the eject mechanism in this injection molding machine,
The electromagnetic clutch 26, the extension shaft 27, the second gear 28, the spline gear 31, and the second timing belt 32 constitute a rotational drive mechanism for the eject rod 18.

With the above structure, when the fixed side mold 4a and the movable side mold 4b are assembled and the molds 4 (a, b) are attached to the mold clamping part 1, as shown in FIG. The driven shaft 15 of the fixed mold 4a in the slide core drive mechanism 10 is fitted into the drive shaft 13 of the movable mold 4b, and the tip of the eject rod 18 in the eject mechanism 16 transmits rotational force. As an output shaft, it engages with the spline fitting hole of the connector 9 on the side of the mold 4 (a, b).

Therefore, the injection molding machine equipped with this slide core drive device can drive the slide core 6 as follows using the NC device (numerical control device) included in the molding machine.

[0025] After the NC device receives a signal indicating the completion of resin injection, pressure holding, and cooling, the electromagnetic clutch 26 is activated and the clutch brake 29 of each ball screw 22 is deactivated.

The ejecting servo motor 20 is rotated in the forward direction, and the slide core 6 moves upward and retreats from the molding cavity 5. Note that for the forward rotation amount, a preset value is extracted from a shared RAM attached to the CPU of the NC device.

At this time, the eject rod 18 rotates, but the ball screw 22 does not rotate, so the eject rod 18 does not move in the axial direction.

When the slide core 6 is retracted completely, the ejecting servo motor 20 is stopped and the electromagnetic clutch 26 is deactivated. Conversely, each clutch brake 29 is put into an operating state. Once the above is confirmed, the mold is opened.

When the mold opening completion signal is received, the ejecting servo motor 20 is further rotated forward by a predetermined amount, the ball screw 22 is rotated, and the knockout bar 17 integrated with the ball nut 21 is advanced. As a result, the eject rod 18 moves forward and pushes the eject pin 8 forward, ejecting the molded product from the cavity 5.

At this time, the electromagnetic clutch 26 is inactive, so the eject rod 18 does not rotate, and the connector 9,
Since the spline gear 31 and the eject rod 18 are spline-fitted, the eject rod 18 is allowed to move in the axial direction without any problem.

[0031] Furthermore, from the movable mold 4b to the fixed mold 4a,
Drive shaft 13 and driven shaft 1 necessary to transmit rotational force to
Since the fitted state with 5 is maintained even at the mold opening completion position, the fitting of both shafts 13 and 15 is not hindered by the mold opening and mold clamping operations.

Next, after a predetermined time or at a set appropriate timing, the ejecting servo motor 20 is reversed, the ejecting rod 18 is returned to its original position, and the mold is clamped. As the eject rod 18 retreats, the eject pin 8 is moved by the spring 7 to release the mold 4 (a
, b).

[0033] At the same time as the mold clamping or when completion of the mold clamping is confirmed, the electromagnetic clutch 26 is activated and the ejecting servo motor 20 is reversely rotated. As a result, the slide core 6 is lowered to a predetermined position in the molding cavity 5, and then injection is performed.

The above is an embodiment in which the drive source of the rotational drive mechanism for the eject rod 18 is the eject servo motor 20 in the eject mechanism 16.

The drive source for the rotational drive mechanism of the eject rod 18 may be a servo motor other than the eject servo motor 20 attached to the eject mechanism 16.

The connector 9 may not be an annular gear, but may be a gear that is pivotally supported by the movable mold 4b and meshes with a wide gear provided at the tip of the eject rod 18 from the outside.

The drive shaft 13 and the driven shaft 15 may be coupled by concave-convex fitting or electromagnetically coupled.

The slide core 6 may be located on the side of the movable mold 4b, or a plurality of slide cores 6 may be provided. Furthermore, it may be a split type.

FIG. 2 shows another embodiment regarding the forward and backward movement and rotation of the eject rod 18.
is a ball screw spline 33, a ball nut 34 and a ball spline nut 35 are attached thereto, and gears 36 and 37 provided thereon are connected to clutch brakes 38 and 39 attached to the output shaft 24 of the eject servo motor 20, respectively. It is connected with a belt. The clutch brakes 38 and 39 are selectively activated or deactivated. As a result, when rotating the eject rod 18, the clutch brake 39 is activated to drive the ball spline nut 35, and when the eject rod 18 is moved forward or backward, the clutch brake 38 is activated and the ball nut 34 is driven.
The slide core 6 can be driven in the same manner as in the above embodiment.

[0040]

[Effects of the Invention] Since there is no drive source for the slide core on the mold side, the structure of the mold is simplified.

[0041] The drive of the slide core can be easily controlled by a control device provided in the injection molding machine.

[0042] It is possible to use the eject servo motor as a drive source for the slide core.

[Brief explanation of the drawing]

[Figure 1] Front view showing the necessary parts in cross section

[Fig. 2] Front view showing a part of another embodiment

[Brief explanation of symbols]

6 Slide core 9 Connector 10 Slide core drive mechanism 16 Eject mechanism 18 Eject rod 20 Servo motor for ejecting

Claims (2)

[Claims] Claim 1: In an eject mechanism of an injection molding machine, an eject rod that moves in the front and rear direction to eject a molded product is rotatably supported around its longitudinal axis, and a rotation drive mechanism is provided for the eject rod. The rod serves as an output shaft for rotational driving force, and on the other hand, a mold having a slide core is provided with a connector that obtains rotational driving force through engagement of the ejector pin, and a sliding core drive mechanism linked thereto, so that the mold clamping part is connected to the platen. A slide core drive device characterized in that the eject rod and the connector on the mold side are engaged with each other when the mold is attached. 2. The slide core drive device according to claim 1, wherein the drive source of the rotational drive mechanism for the eject rod is an eject servo motor in the eject mechanism.