JPH0518809Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an extrusion molding machine for continuously molding outer jackets of electric wires and cables, and particularly to an extrusion molding machine having an extrusion screw extraction function.

[Conventional technology and its problems]

This type of extrusion molding machine has a hopper for introducing the mixture at the rear of the cylinder into which the screw is rotatably inserted, and a crosshead at the tip of the cylinder. When the mixture is bitten into the cylinder from the hopper, fed into the cylinder, receives heat from the cylinder wall, melts, and is kneaded by the shear force generated between the cylinder wall and screw surface. At the same time, it is sent to the crosshead, where the mixture is coated on the conductors running therein.

By the way, when working with this extrusion molding machine,
Due to reasons such as changing molding mixtures, it becomes necessary to replace the extrusion screw. When extrusion screws are replaced, it is common to push the screw from the rear end and pull it out toward the crosshead.

In this conventional screw replacement, after removing the crosshead, a threaded rod 4 with a handle 3 is attached to the rear surface of the screw drive gear case 2 at the rear of the cylinder 1 via an arm A, as shown in FIG. By screwing in the threaded rod 4, its tip pushes the rear end of the screw 5 and pulls it out.

However, as shown in the figure, the screw base is unstable because it is fixed by arm A.
There is a problem that the extrusion force is not applied smoothly to the screw 5, and since it is performed manually, there is a problem that it cannot be applied to large objects.

[Purpose of invention]

In view of the above points, the present invention aims to provide an extrusion molding machine that is easy to screw out and replace.

[Means for solving the problem] In order to achieve the above purpose, in the present invention,
Attaching a hopper for introducing the mixture to the rear of the cylinder into which the screw is rotatably inserted,
In the extrusion molding machine described above with a crosshead attached to the tip of the cylinder, a gear case with a motor is fixed to the rear end of the cylinder, and a screw hole coaxial with the screw is formed in the center of the output gear in this case. At the same time, a through hole was formed in the gear case opposite to this screw hole, and a threaded rod was inserted into the through hole so as to be movable only in the axial direction.

[Effect]

In an extrusion molding machine constructed in this way, when replacing the screw, first remove the crosshead, insert the threaded rod into the through hole, and thread it through the threaded hole of the gear, and then drive the motor. Due to the threaded connection of the threaded rod, the threaded rod advances toward the screw and pushes against the rear surface of the screw. This action allows the screw to be pulled out. After removing the screw, rotate the motor in reverse to move the threaded rod back, and insert and install a new screw into the cylinder.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, in the extrusion molding machine described above, a gear case 7 to which a geared motor 6 is attached is fixed to the rear of the screw drive gear case 2 at the rear of the cylinder 1. This sticking is caused by welding,
This may be done by tightening bolts or the like, and may be removable. An output gear 8 and a pinion 9 connected to the geared motor 6 are built into the gear case 7 to constitute a reduction mechanism, and a screw hole 10 coaxial with the screw 5 is formed in the center of the gear 8. ing. A through hole 11 is formed in the gear case 7 opposite to this screw hole 10, and axial keys 12 are provided on the upper and lower inner surfaces of the through hole 11, and the screw rod is fitted into the key 12. 13 is inserted through the through hole 11 so as to be movable only in the axial direction, and is inserted into the screw hole 10 of the gear 8.
screwed into. Although the gear 8 does not have a rotating shaft, it will not rattle if the threaded rod 13 is always screwed through. However, in consideration of the possibility that the threaded rod 13 may come out, it is preferable that the peripheral boss portion of the threaded hole 10 be supported on the gear case 7 as a shaft portion.

The rear part of the cylinder 1 has the same structure as the conventionally known structure, and as described above, the gear 2a in the screw drive gear case 2 can be inserted into and removed from the shaft 5a of the screw 5 using the key 2b and the keyway 5b. By pushing the rear end of the shaft 5a forward, the screw 5 moves forward and comes out of the cylinder 1.

This embodiment is constructed as described above, and when replacing the screw 5, first remove the crosshead, insert the threaded rod 13 through the through hole 11, and thread it through the threaded hole 10 of the gear 8. When the geared motor 6 is driven, the threaded rod 13 advances toward the screw 5 due to the screw connection between the gear 8 and the screw rod 13, pushes the rear surface of the screw 5, and the screw 5 is pulled out.

When the screw 5 is removed, the geared motor 6
is reversed to move the threaded rod 13 backward, and
Insert and install a new screw into cylinder 1.

[Effect of idea]

The present invention is configured as described above and the screw is pulled out by motor drive, so the screw can be replaced easily and is particularly suitable for large-sized devices.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an embodiment of an extrusion molding machine according to the present invention, FIG. 2 is a sectional view of a threaded rod in FIG. 1, and FIG. 3 is a sectional view of a main part of a conventional example. 1...Cylinder, 2...Drive gear case, 6
...Geared motor, 7...Gear case, 8...
...Output gear, 9...Pinion, 10...Screw hole,
11...Threaded hole, 12...Key, 13...Threaded rod.

Claims (1)

[Scope of utility model registration request] In an extrusion molding machine, a hopper for introducing the mixture is attached to the rear of the cylinder into which the screw is rotatably inserted, and a crosshead is attached to the tip of the cylinder.A gear case with a motor is fixed to the rear end of the cylinder, and inside this case A screw hole coaxial with the screw is formed in the center of the output gear, and a through hole is formed in the gear case opposite to this screw hole, so that the screw rod can be moved only in the axial direction. An extrusion molding machine having a screw removal function, characterized in that the screw is inserted into a through hole and screwed through the screw hole.