JPH04301411A - Method for supplying material of rubber material preparation device - Google Patents

Abstract

PURPOSE:To provide the supply method of a rubber-material preparation device with a material, in which no dispersion is generated in the weight of a rubber material lump and which can extrude the rubber material lump in accurate weight. CONSTITUTION:A rubber material is charged into a material-feed cylinder 4 while turning a feed screw 7 at constant speed, and the rubber material is being pushed into a feed head 1 while being kneaded by the feed screw 7. The rubber material fed to the feed head 1 is passed through a transfer valve 2 and introduced into a metering cylinder 3, and pushes up a metering plunger 5 under a free state gradually, and the inside of the metering cylinder 3 is filled slowly with the rubber material. The rubber material is pushed in gradually only by the torque of the feed screw 7 at that time.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material feeding method in a rubber material preparation apparatus for preparing rubber material for molding (rubber material mass weighed to a predetermined weight) for use in compression molding or the like.

0002

[Prior Art] Conventionally, when preparing a rubber material for molding used in compression molding, etc., for example,
Rubber material, that is, a lump of rubber material weighed to a predetermined weight, was prepared using the apparatus and method shown in the publication.

That is, as shown in FIG. 4A, first, a tape-shaped rubber dough is introduced into the material supply cylinder 20 through its input port, and the screw plunger 21 is rotated. At this time, the screw plunger 21 moves backward in the right direction in FIG. 4a due to back pressure, and the material supply cylinder 20
The rubber material is introduced into the tip of the rubber material while being kneaded.

When the screw plunger 21 is retracted to a predetermined position, the switching valve 22 in the supply head 23 is switched as shown in FIG. 4b, and the push cylinder 24 moves the screw plunger 21 forward to the left in FIG. 4b. As a result, the rubber material flows into the metering cylinder 25 in the supply head 23 through the switching valve 22 while pushing up the metering plunger 26, and the metering plunger 26 stops when it hits the stopper 27, and a certain amount of the rubber material flows into the metering cylinder 25. 25 is filled.

Then, the switching valve 22 is switched as shown in FIG. 4c, and the metering plunger 26 is pushed down by a certain stroke by a hydraulic cylinder (not shown), thereby extruding the rubber material from the extrusion port of the supply head 23.
Next, as shown in FIG. 4d, the measured rubber material mass is cut by the cutting blade 28 and supplied.

[0006]

[Problems to be Solved by the Invention] However, in the conventional method, as described above, the screw plunger 21 is pushed in by the pushing cylinder 24, and the rubber material in the material supply cylinder 20 is measured while applying high pressure to the rubber material. Because the rubber material flows into the cylinder 25, there is a local density difference in the rubber material in the material supply cylinder 20, which causes the compression ratio of the rubber material to vary each time it is supplied, resulting in variations in the weighed weight of the rubber material. there were.

That is, the two graphs a and b in FIG. 5 show the change in the weight of the rubber material lump with respect to the number of extrusions of the rubber material when extruded by the conventional material supply method. As can be seen from b, the weight of the rubber material mass varied by about 0.2 g each time the rubber material mass was extruded.

The present invention has been made to solve the above-mentioned problems, and provides a rubber material preparation device that can extrude rubber material lumps of accurate weight without causing variations in the weight of the rubber material lumps. The purpose is to provide a material supply method.

[0009]

[Means for Solving the Problems] To this end, the material supply method of the rubber material preparation device of the present invention is to fill a measuring cylinder in a supply head with the rubber material introduced into a material supply cylinder, and to fill the measuring cylinder in a supply head. In the material supply method of a rubber material preparation device, which extrudes and supplies a certain amount of rubber material from the extrusion part of the supply head by pushing a metering plunger into the material supply cylinder, the rubber material is is characterized in that it is pushed into a supply head and filled into a metering cylinder.

0010

[Operation] Rubber material is introduced into the material supply cylinder while rotating the supply screw at a constant speed, and the rubber material is pushed into the supply head while being kneaded by the supply screw. The rubber material supplied to the supply head passes through the switching valve and enters the metering cylinder, gradually pushes up the metering plunger in the free state, and the rubber material is filled into the metering cylinder. At this time, the rubber material is gradually pushed in only by the rotational force of the supply screw, so
The pressure applied to the rubber material is about half that of the conventional case, and there is almost no local density difference caused by the high pressure in the rubber material forced into the supply head.

When the metering plunger has risen to the set position, the rotation of the supply screw is stopped, the switching valve is switched, and the metering plunger is pushed into the metering cylinder by a predetermined stroke. Extrusion supplies heavy rubber materials.

[0012] By repeating the above operations, rubber material lumps are continuously produced, but since the rubber material is gradually pushed into the supply head only by the rotational force of the supply screw, the pressure applied to the rubber material is reduced. is relatively low, and the rubber material pushed into the feed head has almost no local density differences due to the high pressure, and the compression ratio of the rubber material in the metering cylinder is almost constant from extrusion to extrusion, resulting in a constant weight with no variation. It is possible to make a lump of rubber material.

[0013]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

First, the schematic structure of the rubber material preparation device is shown in FIG.
To explain, 1 is a supply head, and within the supply head 1, a material passage is formed in the horizontal direction. An extrusion part 1a is opened and formed at the left end of the material passage, and a material supply cylinder 4 is connected to the right end so as to push the material therein. Further, a switching valve 2 is disposed approximately in the center of the material passage, and a measuring cylinder 3 is formed in communication with the switching valve 2 above.

The switching valve 2 is a three-way switching valve, and switches whether the measuring cylinder 3 is communicated with the material supply cylinder 4 or with the extrusion section 1a by a motor or the like (not shown). A metering plunger 5 is fitted into the metering cylinder 3 so as to be movable up and down with its upper portion protruding upward.

The material supply cylinder 4 is formed with an input port 4a for inputting rubber material, and a supply screw 7 rotated by a motor 6 is inserted into the cylinder so as to knead the rubber material and send it to the supply head. will be placed in

Above the supply head 1 is a metering plunger 5.
An extrusion cylinder 8 for extruding rubber material by pressing down is arranged vertically with its piston rod facing downward. A stopper 9, which the tip of the metering plunger 5 contacts, is replaceably attached to the tip of the piston rod, and by changing the thickness of the stopper 9, the weight of the rubber material mass to be extruded can be changed.

Reference numeral 10 denotes a proximity switch for detecting the rise of the metering plunger, which is attached near the stopper 9, and outputs a detection signal when the metering plunger 5 rises and comes into contact with the stopper 9. Reference numeral 11 denotes a cutting blade for cutting the rubber material, and is disposed above and outside of the extrusion portion 1a of the supply head 1.

Next, the material supply method of the rubber material preparation device will be explained with reference to FIG.

First, a tape-shaped dough (
Rubber material) is introduced into the material supply cylinder 4 from the input port 4a. The rubber material advances toward the left in FIG. 1A and enters the supply head 1 while being kneaded by the supply screw 7.

Then, as the rubber material is further supplied to the supply head 1, it passes through the switching valve 2 and enters the metering cylinder 3, gradually pushing up the metering plunger 5 in the free state, and the rubber material flows into the metering cylinder 3. (Fig. 1B). At this time, the rubber material is fed to the supply screw 7.
Since the rubber material is gradually pushed in only by the rotational force of Almost no density difference occurs.

When the tip of the metering plunger 5 comes into contact with the stopper 9, this is detected by the proximity switch 10, and at this time, the motor 6 stops and the supply screw 7
rotation is stopped, and the switching valve 2 is switched to communicate the metering cylinder 3 with the extrusion section 1a.

Next, as shown in FIG. 1C, the extrusion cylinder 8 lowers its piston rod. Then, the piston rod pushes the metering plunger 5 into the metering cylinder 3 via the stopper 9, whereby the rubber material is extruded to the outside from the extrusion portion 1a. Then, when the metering plunger 5 stops at the lower end, a measured constant weight of rubber material is extruded from the extrusion section 1a.

In this state, the cutting blade 11 descends, and a certain weight of rubber material extruded from the extrusion part 1a is cut off.
A rubber material mass is produced.

Then, the extrusion cylinder 8 raises its piston rod and stopper 9 to the position shown in FIG. 1A, and the switching valve 2 is switched to communicate the metering cylinder 3 with the material supply cylinder 4. Then, the supply screw 7 is driven to rotate again, and similarly to the above, the rubber material is filled into the measuring cylinder 3 and extruded by the extrusion cylinder 8. By repeating the above-mentioned operation, rubber material lumps are produced one after another. It will be made.

Graphs A and B in FIG. 2 show experimental results when a rubber material was extruded using the above material supply method, and show changes in the weight of the rubber material lump with respect to the number of extrusions of the rubber material. As can be seen from graphs A and B, the variation in the weight of the rubber material mass is approximately 0.08g when it reaches a stable range.
Therefore, the variation in the weight of the rubber material lumps is greatly reduced to about 2/5 compared to the conventional method, and it is possible to extrude rubber material lumps with accurate weights.

[0027]

As explained above, according to the material supply method of the rubber material preparation device of the present invention, by rotating the supply screw in the material supply cylinder, the rubber material is pushed into the supply head and into the measuring cylinder. Since the rubber material is gradually pushed into the supply head only by the rotational force of the supply screw, the pressure applied to the rubber material is relatively low, and the rubber material pushed into the supply head is , almost no local density differences occur due to high pressure. Therefore, the compression ratio of the rubber material in the measuring cylinder becomes almost constant for each number of extrusions, and it is possible to continuously produce rubber material lumps of constant weight without variation.

Furthermore, since the pushing cylinder used in the conventional rubber material preparation apparatus is not required, equipment costs can be reduced. Furthermore, unlike conventional rubber material preparation devices, the supply screw does not move inside the material supply cylinder by the push cylinder, so the tape-shaped rubber material may be forcibly pulled and cut at the input port of the material supply cylinder. No problems will occur.

[Brief explanation of drawings]

FIG. 1 is a process explanatory diagram of a material supply method of a rubber material preparation device.

FIG. 2 is a graph showing the change in weight of a rubber material lump with respect to the number of extrusions.

FIG. 3 is a schematic configuration diagram of a rubber material preparation device.

FIG. 4 is a process explanatory diagram of a conventional material supply method.

FIG. 5 is a graph showing the change in weight of a rubber material lump with respect to the number of conventional extrusions.

[Explanation of symbols]

1 - supply head, 2 - switching valve, 3 - metering cylinder, 4 material supply cylinder, 5 - metering plunger, 7 - supply screw.

Claims (1)

[Claims] Claim 1: A metering cylinder in a supply head is filled with rubber material input into a material supply cylinder, and a metering plunger is pushed into the metering cylinder, whereby a certain amount of rubber is delivered from the extrusion part of the supply head. In the material supply method of the rubber material preparation device that extrudes and supplies the material, the rubber material is pushed into the supply head and filled into the measuring cylinder by rotating a supply screw in the material supply cylinder. Material feeding method for rubber material preparation equipment.