JPH042033Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a jig for removing the screw of an in-line screw type injection molding machine from a heating cylinder.

(Prior Art) In an in-line screw type injection molding machine, the screw that performs injection is sometimes removed from the heating cylinder for purposes such as cleaning. In this case, the molten resin must be softened, but even so, the resistance when removing the screw is not small if the resin is viscous. Especially with large screws, it was impossible to do so without using mechanical power.

Therefore, conventionally, as shown in FIG. 4, an operator inserts a push rod 5 of an appropriate length between the screw fitting hole 3 of the drive shaft 2 for advancing, retracting, and rotating the screw 1 and the rear end surface 4 of the screw 1. While holding the screw 1, the drive shaft 2 performs an injection operation at a low speed to push the screw 1 toward the distal end. Furthermore, the reciprocating distance of the drive shaft 2 is fixed, and there are cases where a single push rod cannot push out the product sufficiently. At that time, after the drive shaft 2 is advanced to the full injection stroke, it is moved back and a push rod is added to cause the drive shaft 2 to perform the injection operation again to push out the screw 1.

(Problem to be solved by the invention) However, in the above-mentioned work, the operator must hold the push rod 5 between the screw 1 and the drive shaft, and furthermore, there are cases where the push rod cannot be pushed out with a single push rod. Since the push rod must be attached and the push rod must be held in an unstable condition,
It was extremely dangerous work.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a jig for holding a push rod on a drive shaft and pushing out a screw without using human hands.

(Means for Solving the Problems) As a means to solve the above problems and achieve the purpose, a drive shaft that supports the rear end of the screw and moves it forward, backward, and rotates is provided with a drive shaft that extends in the axial direction of the screw. A through hole is bored, a push rod is inserted into the through hole, one end of the push rod is detachably attached to the drive shaft, and the other end of the push rod is brought into contact with the rear end surface of the screw from the axial direction of the screw. That's what happens.

(Function) With the above configuration, the push rod is inserted into the through hole drilled in the drive shaft to hold one end, the other end is brought into contact with the rear end surface of the screw, and then the drive shaft is caused to perform the injection operation. The screw is pushed out toward the tip. If the push rod is not long enough, the screw can be pushed out a predetermined length by retracting the drive shaft, removing the push rod, pulling it out from the through hole, and replacing it with a longer push rod.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is a longitudinal sectional view of this embodiment, and the configuration will be explained using this.

A screw 7 is inserted into the heating cylinder 6 so as to be freely movable forward and backward. A reduction gear housing 9 containing a drive shaft 8 is provided behind the screw 7, and an injection piston 11 of an injection cylinder 10 is connected to the reduction gear housing 9. The injection cylinder 10 supplies and discharges pressurized oil from hydraulic oil inlets and outlets 12 and 13 to cause the reducer housing 9 to reciprocate.

The drive shaft 8 has a bearing 1 in the reducer housing 9.
4 and 14, and a fitting hole 15 into which the rear end of the screw 7 is fitted is formed in the front end, and a rotation from a drive source such as a hydraulic motor (not shown) is provided in the middle part. A rotary drive gear 16 is provided for transmitting.

Next, the main parts of the present invention will be explained.

A through hole 17 is formed along the axis of the drive shaft 8. The through hole 17 has a diameter that is sufficiently smaller than the diameter of the rear end surface 7a of the screw 7, and the fitting area 15 of the screw 7 is secured to withstand a large injection force.

A flange 18 is connected to the bolt 1 at the rear end of the drive shaft 8.
It is removably attached with 9 and 19, and the push rod 2
0 is inserted into the through hole 17, the through hole 17 is closed by the flange 18, and the push rod 20 is supported.

As shown in FIG. 3, a chamfered portion 20a is formed on the tip side of the push rod 20, and a recessed portion 7b into which the chamfered portion 20a can be fitted is formed on the rear end surface 7a of the screw 7. There is. In this way, the push rod 20 and the screw 7 reliably abut without slipping.

Next, the effects of the above configuration will be explained.

With the reducer housing 9 retracted, a push rod 20 of a length that can come into contact with the rear end surface 7a of the screw 7 is inserted into the through hole 17, and the flange 18 is fixed with the bolt 19,
Fixed at 19.

Next, pressurized oil is supplied from the hydraulic oil inlet/outlet 13 of the injection cylinder 10 to operate the injection piston 11 and move the reducer housing 9 forward. Accordingly, the push rod 20 pushes the screw 7 forward (see FIG. 2).

If the pushed out screw 7 still does not come out, the reducer housing 9 is moved backward, the flange 18 is removed and replaced with a long push rod, and the above operation is repeated again.

In this way, the screw 7 is pushed out from inside the heating cylinder 6.

The extruded screw 7 is cleaned and reinserted into the heating cylinder 6, and its rear end is fitted into the fitting hole 15 of the drive shaft 8, as shown in FIG. Further, the split ring 21 is attached to the stepped portion 7c, and the split ring 21 is fixed to the drive shaft 8 with the presser foot 22, so that the screw 7 is connected to the drive shaft 8 and injection molding is performed.

(Effects of the invention) As explained in detail above, the push rod is supported on the drive shaft so that the screw is pushed out of the heating cylinder by the injection operation, and the length of the push rod can be easily changed, allowing for removal of the screw. The effect is that the work can be done safely and easily.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of one embodiment of the present invention;
The figures are a diagram showing the operating state of Figure 1, Figure 3 is an enlarged view of the shape of the abutting part between the screw and the push rod, Figure 4 is a diagram showing the conventional method for removing the screw, FIG. 5 is an enlarged view showing the means for fixing the screw and the drive shaft. 7... Screw, 7a... Rear end surface, 8... Drive shaft, 20... Push rod.

Claims (1)

[Scope of utility model registration request] A through hole in the axial direction of the screw is formed in a drive shaft that supports the rear end of the screw to move it forward, backward, and rotate, a push rod is inserted into the through hole, and one end of the push rod is connected to the drive shaft. A screw removal jig, which is detachably attached to the screw and has the other end of the push rod abutted against the rear end surface of the screw from the axial direction of the screw.