JPS5818898B2 - resin molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin molding machine having a plurality of heating cylinders.

Conventional screw injection molding machines are driven by connecting a heating cylinder with a built-in screw shaft to the screw drive shaft. For example, when changing the color of resin, new resin is injected until there is no remaining resin in the heating cylinder. We continue to send them and mold them.

Therefore, products that are molded before the resin is completely replaced are discarded as defective products, which has the disadvantage of wasting material.

In addition, during the molding process, heating cylinders are frequently replaced due to changes in materials and molding methods, but this requires time and effort to change setups, such as having to suspend the heating cylinder with a winch while removing it. There was a problem.

In view of the above-mentioned circumstances, the present invention provides a molding machine that can solve the above-mentioned problems at once by switchably disposing a plurality of heating cylinders in one molding machine.

The present invention will be specifically described below based on embodiments shown in the drawings.

The drawing shows a screw shaft 41 installed inside the heating cylinder 4.
This figure shows the state in which the present invention is implemented in an in-line injection molding machine that serves as both a kneading machine and an injection plunger.

The injection molding machine has a mold clamping mechanism 2 on one side of the molding machine body 1, and an injection mechanism 3 on the other side that can approach and separate from the mold clamping mechanism 2. forms a space 11 in which a heating cylinder 4, which will be described later, is accommodated.

The injection mechanism 3 includes a frame 30 that slides on the main body 1, and the frame 3.
Two heating cylinders 4, 4a arranged so as to be swingable at 0
and a screw drive device 31 that drives a screw shaft 41 built into the cylinder.

As shown in FIG. 2, the frame 30 is fixed to a slide plate 32 that is slidably fitted into the guide groove 12 of the main body 1, and is reciprocated toward the mold clamping mechanism 2 by a hydraulic cylinder 33 connected to the slide plate 32. do.

The screw drive device 31 has a cylinder 35 provided with a plurality of axial key grooves 34 on its inner surface, which is freely rotatable in the frame 30, and can be slid by fitting a drive shaft 36 having a spline shaft part 21 into the core part 35. And they are engaged so that they rotate together.

The cylinder 35 has a sprocket 37 on its outer periphery, and the sprocket is connected to a motor 38 with a speed reducer disposed on the frame 30.

A hydraulic cylinder 5 is attached to the rear wall 39 of the frame body 30, and a piston rod 51 that slidably passes through the rear wall 39 is connected to the rear end of the drive shaft 36 by a rotary joint so that it can rotate freely and move back and forth as a unit. .

A swinging body 6 is further pivotally fixed to the frame 30 at the end thereof on the side of the mold clamping mechanism 2 so as to be rotatable in a vertical plane.

The rocking body 6 includes a pair of side plates 61 arranged on both sides of the frame body 30,
61, each proximal end is connected to the frame 30 by a short pivot 62.
The side plate is pivoted to be freely rotatable, and the tip of the side plate is connected by a mounting plate 63.

A worm gear 64 is fixed to one of the pivot shafts 62, 62, and is engaged with a worm 65 rotatably attached to the frame 30.

The worm 65 is rotated by hand or linked to a deceleration motor 66 with a reversing device, and rotates the rocking body 6 in the vertical direction about the pivot 62 by operating a switch.

The mounting plate 63 at the tip of the oscillating body 6 is bent at the center, and the upper surface 67 is inclined at 30 to 40 degrees toward the frame body with respect to the lower surface 68. A through hole 60, 60 is formed in the center to face the center during rotation of the rocking body 6, and cylindrical holders 69, 69 are fixed outwardly concentrically with the reading tag.

Heating cylinders 4 and 4a each having a built-in screw shaft 41 are fitted into the holders 69 and 69, respectively, and the material supply hole 52 formed on the side surface of the holder 69 is aligned with the hole 53 formed on the side surface of the heating cylinder 4. let

The supply hole 52 of each holder 69 has a material hopper 7=7a.
As shown in FIG. 4, the lower hopper 7 is laterally attached via an inclined pipe 71 on the side that does not collide with the upper heating cylinder 4a.

The screw shafts 41, 41a protruding from the base ends of the heating cylinders 4, 4a may fall down or the screw drive device 3
1 drive shaft 36 and the locking means 8, and when the rocking body 6 is rocked to the upper or lower position, the lower or upper heating cylinders 4, 4a are connected to the drive shaft 3.
It is on the same extension line as 6 and can be directly connected.

The locking means 8 of this embodiment has an insertion hole 81 at the tip of the drive shaft 36.
is opened, the base end of the screw shaft 410 is fitted into the insertion hole 81, and the clamp bolt 82 is pressed and fixed.

The locking means 8 is not limited to the above, and it goes without saying that a chuck mechanism that can rotate and axially move the screw shaft 41 together with the drive shaft 36 can be used.

A case in which the oscillator 6 is oscillated to the upper position and the screw shaft 41 of the lower heating cylinder 4 is connected to the screw drive shaft 36 will be described.

The motor 38 of the screw 1 driving device 31 is operated to rotate the lower screw shaft 41, and the pellets supplied from the hopper 7 are melted by the heat of the heating cylinder 4 and sent to the tip side of the screw shaft 41.

When molten resin accumulates on the front part of the screw shaft, the internal pressure causes the screw shaft to retreat.

Next, the frame 30 is moved to the mold clamping mechanism 2 side by the cylinder 33, the nozzle at the tip of the heating cylinder 4 is applied to the sprue of the mold clamping mechanism 2, and then the screw shaft 41 is advanced by the operation of the hydraulic cylinder 5, and the molten resin is moved forward. Pour into mold.

The mold is opened, the molded product is taken out, and the above operations are repeated to perform injection molding exactly the same as in a normal injection molding machine.

When producing two types of molded products of the same type in different colors, first, a predetermined quantity of one type of molded product is manufactured using pellets placed in the lower hopper 7.

Next, the frame 30 is moved outward to separate the nozzle and sprue, the clamp bolt 82 of the locking means 8 is loosened, the drive shaft 36 is moved backward, and the connection with the screw shaft 41 is removed.

In this state, the worm 65 is rotated to rotate the rocking body 6 downward so that the axes of the upper heating cylinder 4a and the drive shaft 36 are aligned.

Next, the drive shaft 36 is advanced by the oil field cylinder 5,
The base end of the upper screw shaft 41a is fitted into the insertion hole 81 of the shaft 36 and fixed with a clamp bolt 82.

In the above state, if injection molding is performed by charging pellets of a different color to the upper hopper 7a than those in the lower hopper 7, a new colored molded product of pellets will be obtained immediately, and no pellets will be mixed with the injection molded product. .

Therefore, there is no loss of material, and the work required to change the color is much easier and faster than the conventional method of suspending the heating cylinder together with the screw shaft using a winch.

As mentioned above, when the heating cylinders 4 and 4a are rotated in a vertical plane, there is an advantage that the heating cylinders 4 and 4a can be operated in a narrow factory space without getting in the way of workers. 30 by attaching it to the heating cylinder 4,4
Of course, it is possible to switch by rotating a in the horizontal plane.

The heating cylinders 4, 4a are arranged so as to be movable up and down parallel to the molding machine main body 1, and any heating cylinder and drive shaft 36
We are also specialized in connecting and switching.

Similarly, when carrying out the present invention, resins with different properties, such as a thermoplastic resin in one hopper 7a and a thermosetting resin in the other hopper 7a, can be injection molded, and furthermore, the thickness of each heating cylinder 7.7a can be By changing the injection volume, the shape of the valley screw is not the same, and for example, one is a constant pitch type screw, and the other is a gradually decreasing pitch type screw, which can be selected according to the characteristics of the resin. You can easily switch.

The present invention can also be implemented in an extrusion molding machine with a single screw by attaching an extrusion die (not shown) to the tip of the heating cylinder 4 and providing only rotational drive to the screw shaft 41 without moving it in the axial direction.

As described above, the present invention allows molding to be carried out by removably connecting the drive shaft 36 to the screw shaft 41 in any cylinder 4 among the plurality of heating cylinders 4 each equipped with a material hopper 7. In this way, there is no possibility of producing defective molded products due to the mixing of different types of pellets, and wasteful consumption of materials can be avoided.

In addition, by attaching the cylinder 4 to a swinging body 6 that rotates in a vertical plane or a horizontal plane, switching between cylinders 4 can be easily performed by simply rotating the swinging body 6, which has many excellent effects. It is something.

[Brief explanation of the drawing]

FIG. 1 is a front view of an injection molding machine according to the present invention, FIG. 2 is a cross-sectional view of the injection mechanism, FIG. 3 is a cross-sectional view taken along the line ■-■ in FIG. FIG. 3 is a sectional view taken along the TV line. 2...Mold clamping mechanism, 30...Frame body, 4,
4a... Heating cylinder, 41.41a...
... Screw shaft, 6 ... Rocking body, 8 ...
...Locking means.

Claims (1)

[Claims] 1. The material hopper 7 is integrally mounted on the extension of the tip of the screw drive shaft 36 provided in the main body 1 of the molding machine, so that a plurality of heating cylinders 4 each having a screw shaft 41 inside can be switched. A resin molding machine characterized by its deployment. 2. The resin molding machine according to claim 1, wherein the screw shaft 41 is rotationally and axially driven by the drive shaft 36 and also serves as a plunger for injection molding. 3 Each heating cylinder 4 has a rocking body 6 whose base end on the drive shaft 36 side is pivoted so as to be rockable within a vertical plane including the drive shaft 36.
A resin molding machine according to claim 1 or 2, which is mounted on the resin molding machine. 4. The resin molding machine according to claim 1 or 2, wherein the valley heating cylinder 4 is disposed in the molding machine main body 1 so as to be movable up and down or rotatable in a horizontal plane.