JPH0154175B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a rotary machine used for molding synthetic resin products having an internal thread.

(Prior Art) Generally, in thread molding, resin is injected between a closed cavity mold and a threaded core, and the threaded core is rotated when the molded product is released from the mold. For this reason, a screw core rotating device is required, and most of these devices are installed inside the cradle of the mold having the screw core.

(Problem to be Solved by the Invention) The internal installation of the rotating device in the mold holder does not pose any structural problems in a normal injection molding machine that opens and closes the mold at the same position, but the turntable does not have any structural problems. Applications to rotary molding machines where multiple screw cores are provided with mold holders to release molded products at different positions, or where molding is performed twice for multicolor molding, are Because the screw core and mold holder are mounted on a moving turntable, the structure is complicated in terms of wiring, etc., and a screw core rotating device is required for each mold, so the design,
Not only does the manufacturing process require special technology, which increases mold manufacturing costs, but the molds also tend to become larger.When selecting a molding machine, it is important to consider the size of the mold rather than the size of the molded product. Problems arise such as having to select a molding machine of a larger class.

(Means for Solving the Problems) This invention was devised to solve the above-mentioned problems when molding threaded products using a rotary molding machine, and its purpose is to: There is no need to provide a screw core rotation device for each mold, and one rotation device can be used to rotate the screw cores of multiple mold holders installed on a turntable, simplifying the structure and improving productivity. An object of the present invention is to provide a rotary screw forming machine.

The present invention for the above-mentioned purpose is such that a mold release plate is movably provided on the mold closing surface of a plurality of mold holders mounted on a turntable facing the cavity mold, and a rotating shaft having a tip formed as a screw core is provided. is inserted through the mold holder with a screw core protruding from the mold release plate, the rear part of the rotation shaft is connected to a rotation mechanism provided on the mold holder, and the screw core is placed at one stop position of the mold holder, A drive device including a transmission shaft that engages with the rotation mechanism is provided on the support member side of the turntable, and the drive device includes a device for engaging and disengaging the rotation mechanism and the drive shaft.

Gears, chains, etc. are used as the rotation mechanism, and an electric motor, a hydraulic motor, etc. are used as the drive device. Regarding the engagement and disengagement of the transmission shaft, either the transmission shaft can be moved directly or together with the drive device.

(Function) In the screw forming machine with the above configuration, the transmission shaft is placed at a position that does not interfere with the rotation of the turntable, and is removed from the rotation axis, and the turntable is rotated. Replace the mold holder. When the turntable rotates and stops,
The transmission shaft moves in the axial direction by the operation of the engagement/disengagement device and engages with the rotation mechanism. When the transmission shaft is rotated by the drive device, the rotation shaft is also rotated by the rotation mechanism, and due to the movement of the release plate and the rotation of the screw core,
The molded product with a thread formed on the inside is demolded.

When the above-mentioned mold release is completed, the transmission shaft returns to its original position by the operation of the locking and disengaging device again, and the turntable can be rotated.

Further, this invention will be explained in detail with reference to Examples.

(Example) Figures 1 and 2 show a vertical rotary molding machine,
1 is a turntable installed horizontally on the machine base 2;
Reference numerals 3 and 4 denote a pair of mold holders mounted on the turntable 1, and these are mounted in positions where they alternately close the molds with the downward facing cavity molds 6 mounted on the movable platen 5.

The movable platen 5 is connected to a ram 8 of a mold clamping cylinder 7 on the upper part of the machine base, and the turntable 1 is controlled by an actuator 9 fixed to the machine base 1.
After rotating 180 degrees, when one mold holder 4 comes to a stop position directly below the cavity mold 6, it is lowered by the ram 8 to close the mold, and after moving to strong mold clamping, the side injection is started. The cylinder 10 is touched with a nozzle, and injection molding of a molded article 11 is performed.

A mold release plate 12,
12 is provided so as to be movable by being constantly pressed upward by spring members 13, 13 housed in the mold holder.

Also, inside the mold holders 3 and 4, there is a screw core 1 at the tip.
A plurality of rotating shafts 15, 15 integrally having 4, 14
However, the screw cores 15, 15 are made to protrude from the mold release plates 12, 12, respectively, and are provided in parallel therewith.

At the rear end of the rotation shafts 15, 15, a mold holder 3,
There are subordinate gears 18, 18 in the lower part of the turntable 1 that mesh with the main gears 17, 17 located in the through hole 16 of the turntable 1, and by the rotation mechanism by these gears, the rotation axis is connected to the screw core. Surrounding molded product 11
Rotate in the direction to pull out.

Reference numeral 19 denotes a drive device for the rotating shaft 15, which is disposed at a stop position of one mold holder 3. This drive device 19
a transmission shaft 21 having a head 21a that fits into a square hole 17a of the main gear 17 facing the through hole 16 from a through hole 20 of the machine top plate overlapping the through hole 16 of the turntable 1; It is equipped with an electric motor 22 that rotates the rotation shaft 15 via the transmission shaft 21 and a rotation mechanism, and the rotational force of the electric motor 22 is transmitted to the transmission shaft 21 through a transmission mechanism 23 consisting of gears and a chain. communicated.

The electric motor 22 and the transmission shaft 21 are connected to the machine base 1
It is attached to a frame 24 fixed to the bottom plate of. The transmission shaft 21 is one gear 23a of the transmission mechanism 23 rotatably attached to the upper part of the frame 24.
Although not shown in the drawings, it is fitted with a spline so that it can move up and down, and its lower end is rotatably connected to the piston 26 of a hydraulic cylinder 25 provided in the frame using a coupling ring 27. be.

The hydraulic cylinder 25 is the head 2 of the transmission shaft 21.
1a and the square hole 17a of the main gear 17, and the upper and lower limit positions of the transmission shaft 21 are detected by proximity switches a and b that operate at the coupling 27 portion.

In such a molding machine, when the mold pedestal 3, which is in the molding position due to the rotation of the turntable 1, is moved to the illustrated position with the molded product 11 attached around the screw core 14 and stopped, The hydraulic cylinder 25 operates, the piston 26 rises, and the transmission shaft 21 placed below the turntable 1 is moved upward. As a result, the head 21 of the transmission shaft 21
a is from the through holes 20 and 16 to the square hole 1 of the main gear 17
7a, the electric motor 22 is activated by the action of the proximity switch c, and the transmission shaft 21 is rotated via the transmission mechanism 23. Furthermore, the rotational force is applied to both rotation shafts 1 via the main gear 17 and the follower gear 18.
5.

When the rotation shaft 15 rotates in the screw removal direction, for example, counterclockwise rotation for a right-handed screw and clockwise rotation for a left-handed screw,
Since the molded product 11 is pressed upward by the mold release plate 12, which is constantly pressed upward by the spring member 13, the screw core 11 is pressed upward by the pressing force and the screw lead as shown in the figure. Get out of 14.

Once the molded product 11 has come out of the screw core 14, the rotation is stopped and the hydraulic cylinder 25 lowers the transmission shaft 21 to its original position. Head 21a
Get off at a place where it will not interfere with the rotation of turntable 1.

FIG. 3 shows an example of application in the case of a rotary two-color molding machine. Two cavity molds 61 on the 28 side,
It is provided opposite to 62. Also, mold holders 3 and 4
As in the previous embodiment, there is a mold release plate 12 and a rotating shaft 15.
The main gear 17 bearing on the arm 29 on the side of the mold holder and the follower gear 18 at the end of the rotating shaft are connected by a chain 30, and are positioned opposite to the cavity mold 62 for molding the second color. The driving device 19 is attached to the side of the movable platen 51 at the stop position of one of the mold holders 3. This drive device 19
An electric motor 22 is mounted on a sliding member 31 connected to a piston 26 of a hydraulic cylinder 25, and the transmission shaft 21 moves together with the electric motor 22 to connect the square hole 17a of the main gear 17 and the head 21a. It is possible to engage and disengage.

Two cavities 61, 6 in this molding machine
2 and the mold holders 3 and 4 are simultaneously opened and closed by the movable platen 51, the turntable 1 is rotated by the actuator 9, and the molded product 1 which has completed two-color molding is
The first screw core 14 is released from the mold when the mold is opened.

(Effects of the Invention) As described above, the present invention provides a drive device for the screw cores penetrating the plurality of mold holders attached to the turntable on the supporting member side of the turntable. Since the screw core of the mold holder is rotatable, there is no need to provide a drive device for the screw core for each mold holder, which simplifies the mold structure and also solves difficulties such as wiring. Therefore, each mold can be manufactured at low cost and in a small size.

In addition, the transmission shaft that engages with the rotation mechanism on the mold holder side,
When the turntable rotates, a locking and disengaging device is installed that moves the turntable to a position that does not interfere with the rotation of the turntable, making it possible to mold threaded items even with a rotary molding machine, and also to allow multicolor molding. It has the advantage that it can also be applied to

[Brief explanation of drawings]

The drawings show an embodiment of the rotary screw forming machine according to the present invention, in which Fig. 1 is a longitudinal sectional view of the main part of the vertical rotary forming machine, Fig. 2 is a side view of the rotating mechanism, and Fig. 3 is a cross-sectional view of the main part of the vertical rotary forming machine. FIG. 2 is a longitudinal cross-sectional side view of the main parts of the two-color rotary molding machine. 1... Turntable, 2... Machine stand, 3, 4...
...Mold pedestal, 6,61,62...Cavity mold, 1
DESCRIPTION OF SYMBOLS 1... Molded product, 12... Release plate, 14... Screw core, 15... Rotating shaft, 17... Main gear, 17a...
...Square hole, 18...Following gear, 19...Drive device, 2
1... Transmission shaft, 22... Electric motor, 23... Transmission mechanism, 25... Hydraulic cylinder.

Claims (1)

[Claims] 1 Mold release plates are movably provided on the mold closing surfaces of a plurality of mold holders mounted on a turntable facing the cavity mold, and a rotating shaft having a screw core at the tip is connected to the mold release plate. A screw core is made to protrude from the plate and penetrate through the mold holder, and the rear part of its rotation shaft is connected to the rotation mechanism provided on the mold holder, and the screw core is connected to the rotation mechanism at one stop position of the mold holder. A rotary screw thread forming machine, characterized in that a drive device having mating transmission shafts is provided on the support member side of the turntable, and the drive device is equipped with a device for engaging and disengaging the rotation mechanism and the drive shaft. .