JPS6323904B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a filling machine for filling expandable resin beads into a mold for molding a thermoplastic resin foam such as expanded polystyrene.

A typical filling machine of this kind that has been used in the past has a raw material supply cylinder equipped with a resin bead supply port 5 and a pressurized air supply port 2 for filling resin beads on the side, as shown in the first figure of the attached drawing. and a piston cylinder, the plunger 1 that can slide inside the raw material supply cylinder and the piston in the piston cylinder are connected by a rod, and furthermore, there are supply and exhaust ports 3 and 4 for pressurized air to operate the piston. It is made up of the following. As mentioned above, such a known filling machine requires a total of three pressurized air supply or air supply/exhaust ports, resulting in a complex piping structure. Furthermore, for molds in which the size of the mold steam chamber 6 provided behind the mold 7 is large, it is necessary to use a material supply tube with a longer length, which reduces the stroke of the plunger and piston. As a result, the overall length of the filling machine must be increased, which is disadvantageous in that it is inconvenient to operate and increases manufacturing costs.

The present invention solves all of these inconveniences at once, and will be described in detail below with reference to the accompanying drawings.

FIG. 2 is a longitudinal sectional view taken along the longitudinal center axis of the filling machine of the present invention. In the figure, the outer cylinder 20 is connected to the piston cylinder 1 through a thick wall at its rear end.
4 are arranged in series, and a spout 23 for jetting resin beads is protruded from the tip. Inside the outer cylinder 20, an inner cylinder 21 having an outer diameter sufficiently smaller than the inner diameter of the outer cylinder 20 is fitted with one end to the thick part of the rear end of the outer cylinder 20, and is supported in a cantilever manner. The end faces behind spout 23. As mentioned above, since the outer diameter of the inner tube 21 is sufficiently smaller than the inner diameter of the outer tube 20, the cylindrical space 19 is formed along the inner wall surface of the outer tube 20.
The rear end of this cylindrical space 19 communicates with a resin bead supply port 16 attached to the side surface of the rear end of the outer cylinder 20, and the front end communicates with the jet beak 23. A rod 17 having an outer diameter slightly smaller than the inner diameter of the inner tube 21 is inserted into the inner tube 21, so that a narrow gap 18 is left between the inner wall of the inner tube 21 and the rod 17. . The rear end of this rod 17 is fixed to the piston 13 which is slidably fitted into the piston cylinder 14, and the plunger 22 is attached to the front end. The plunger 22 has a cross-sectional shape that matches the cross-sectional inner shape of the jet beak 23, and is designed to have dimensions that allow it to be fitted into and removed from the jet beak. Further, a compressed air supply/exhaust port 12 is provided at the rear end of the piston cylinder 14, and a compressed air supply/exhaust port 11 is also provided at the thick joint between the outer cylinder 20 and the piston cylinder 14.
is bored and opens toward the narrow gap 18 in the inner cylinder 21. The inner opening of the supply/exhaust port 11 is located at a suitable location 15 near the piston cylinder 14. Furthermore, the inner diameter of the tip of the inner cylinder 21 is
It is enlarged to be slightly larger than the outer diameter of the plunger 22, and when the plunger 22 retreats, a narrow gap is left between the plunger 22 and the inner wall of the inner cylinder 21, and the plunger 22 is housed therein. ing. Further, the narrow gap 18 between the inner cylinder 21 and the rod 17 is enlarged 15 from at least a portion including the inner opening of the air supply/exhaust port 11 to the piston cylinder 14. This is preferable because it makes the operation easier.
More preferably, the length of the enlarged part 15 is determined so that the inner opening of the supply/exhaust port 11 faces the enlarged narrow gap part 15 until the piston 13 reaches its most retracted position. However, the above-mentioned expansion is not necessarily necessary, and therefore is not essential. Furthermore, the length of the rod 17 is determined by the length of the piston 13.
When plunger 2 reaches its most advanced position, plunger 2
If the front end surface of the foam molding 2 and the front edge of the spout 23 are set on the same plane, no trace of the spout will be left on the foam molded product. Next, when the piston 13 is in the most retracted position, the plunger 22
However, at this time, since the narrow gap formed between the inner cylinder 21 and the plunger 22 acts as a jet nozzle as described later, the front end surface of the plunger 22 and the front end of the inner cylinder 21 Most preferably, it is substantially on the same plane as the To do this, the relationship between the jet beak 23 and the plunger 22 is taken into account, and the dimensions of the inner cylinder 21 are adjusted so that the distance between the front edge of the jet beak 23 and the front end of the inner cylinder 21 is substantially equal to the stroke of the piston 13. All you have to do is determine.

Next, the operation of the filling machine of the present invention will be described with reference to FIGS. 2 to 4.

As shown in Fig. 2, the filling machine has two mold steam chambers.
6 and fit the spout 23 into the raw material supply hole on the wall of the mold 7, and after adjusting the mounting position adjusting flange 24 so that the tip of the spout 23 properly matches the inner wall surface of the mold, the tightening flange 25 and attached to the molding machine. The figure shows a state in which compressed air is forced into the air supply/exhaust port 12 to move the piston 13 forward most, and the jet beak 23 is closed by the plunger 22. Next, in Figure 3,
If the supply/exhaust port 12 is switched to exhaust mode and compressed air is introduced from the supply/exhaust port 11, the narrow gap enlarged portion 15
Compressed air flows into the At this time, since the sliding resistance of the piston 13 is smaller than the resistance to the air flow in the narrow gap 18, the compressed air first acts to move the piston 13 backward.

FIG. 4 thus shows the piston 13 in its most retracted state. When this state is reached, the compressed air flow passes through the narrow gap 18 and is ejected toward the jet beak 23 from the narrow gap 28 formed by the inner cylinder 21 and the plunger 22 housed in the front end portion thereof. Since negative pressure is generated in the cylindrical space 19 by this jet flow,
Accompanied by air sucked and flowing in from a bead hopper or the like (not shown) connected to the resin bead supply port 16, the resin beads pass through the bead supply port 16 and the cylindrical space 19, and are supplied from the spout 23 to the inside of the mold 27. be done. When the supply of resin beads is completed, the supply/exhaust port 11 is switched to exhaust, and the supply/exhaust port 12 is switched to exhaust.
When more air is supplied, the piston 13 moves forward and the plunger 22 closes the jet beak 23.

Next, another embodiment of the filling machine of the present invention will be explained with reference to FIGS. 5 and 6.

FIG. 5 shows an example in which a valve mechanism for opening and closing the narrow gap 18 is provided in order to make the operation of the piston 13 of the filling machine of the present invention more reliable. That is, a valve ring 29 for closing the narrow gap 18 is fixedly attached to a suitable position of the rod 17. The mounting position of the valve ring 29 is such that when the piston is in the forward position, the valve ring 29 is located in front of the opening in the narrow gap of the supply/exhaust port 11, and when the piston 13 is in the retracted position, the valve ring 29 is located in front of the opening in the narrow gap of the supply/exhaust port 11. It must be positioned at the rear. Most preferably, the position is selected such that the valve ring 29 is immediately behind said opening when the piston 13 is retracted the most. In this specific example, when the piston 13 is in the forward state, the entire amount of compressed air press-ined from the air supply/exhaust port 11 effectively acts on the piston 13 without leaking through the narrow gap 18, thereby preventing the backward movement of the piston 13. Make it easy and sure.

FIG. 6 shows a still different embodiment for performing the same function as the embodiment shown in FIG. That is, an annular protrusion 30 for closing the narrow gap 18 is provided on the inner wall of the intermediate portion of the inner cylinder 21, and an annular groove 31 surrounding the rod 17 is bored at an appropriate position of the rod 17. At the position where the annular groove 31 meets the protrusion 30,
It has sufficient width and depth to form an air flow path between the two. In addition, the protrusion 30 and the annular groove 3
The relative position with respect to 1 is determined so that when the piston 13 retreats and reaches the rearmost part, the protrusion 30 and the annular groove 31 match to form an air flow path and communicate the front and rear narrow gaps 18. It will be done. The operation of this example will also be explained in the same manner as the example of FIG. 5 described above.

Since the filling machine of the present invention has the above-described structure and function, even if the size of the mold steam chamber 26 is large, there is no need to increase the stroke of the plunger, and it is not necessary to increase the stroke of the plunger. Only two exhaust ports are required, making it possible to reduce the size and weight, and not only improve operational convenience such as installation and operation of the mold, but also reduce production costs. It has the following advantages.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventionally known foamable resin bead filling machine. Figures 2 to 6 are longitudinal sectional views of the filling machine of the present invention, with Figure 2 showing the filling machine in its closed state, Figure 3 showing the state at the start of operation, and Figure 4 showing the state at the time of filling resin beads. 5 and 6 respectively.
indicates another aspect. 1... Plunger, 2... Pressure air supply port, 3,
4... Supply/exhaust port, 5... Resin bead supply port, 6... Mold steam chamber, 7... Mold, 11, 12... Supply/exhaust port, 13
...Piston, 14...Piston cylinder, 15...
Narrow gap enlargement part, 16... Resin bead supply port, 17... Rod, 18... Narrow gap, 19... Cylindrical space, 20... Outer cylinder, 21... Inner cylinder, 22... Plunger, 23... Spout beak, 24... Installation position adjustment flange for use, 25...tightening flange, 26...mold steam chamber, 27...mold, 28
...Narrow gap, 29...Valve ring, 30...Protrusion, 31
...Annular groove.

Claims (1)

[Claims] 1. An outer cylinder 20 with a piston cylinder 14 connected to the rear end and a jet beak 23 protruding from the tip, and a cylindrical space 19 formed along the inner wall surface of the outer cylinder 20. A narrow gap 18 is formed between the inner cylinder 21 and the inner wall surface of the inner cylinder 21.
The rod 17 is inserted into the inner cylinder 21 leaving behind the rod 17,
It consists of a piston 13 that is fixed to the rear end of the rod 17 and can slide inside the piston cylinder 14, and a plunger 22 that is connected to the front end of the rod and can be inserted into and removed from the jet beak 23. An inner cylinder 21 is provided in the thick part connecting the outer cylinder 20 and the piston cylinder 14.
A supply/exhaust port 11 is provided that opens in the piston cylinder vicinity portion 15 of the inner narrow gap 18, and the inner diameter of the tip portion of the inner cylinder 21 is set to a retracted plunger 2.
The cylindrical space 19 is enlarged to such an extent that it can be accommodated with a narrow gap 28 remaining between it and the inner wall of the inner cylinder, and the rear end of the cylindrical space 19 communicates with the resin bead supply port 16, and the front end thereof communicates with the jet beak 23. A foamable resin bead filling machine characterized by being configured as follows. 2. A valve ring 29 that closes the narrow gap 18 is fixed to the rod 17, and when the piston 13 moves forward, the valve ring 29 is located forward of the narrow gap opening of the air supply/exhaust port 11, and the piston 13 is 2. The foamable resin bead filling machine according to claim 1, wherein the fixing portion of the valve ring 29 is positioned behind the opening in the retracted position. 3 Convex strip 3 that closes the narrow gap 18 on the inner wall of the inner cylinder 21
0 is provided around the rod 17, and an annular groove 31 surrounding it is bored in the rod 17 so that the protrusion 30 and the annular groove 31 match at the most retracted position of the piston 13, allowing the front and rear narrow gaps 18 to communicate with each other. , the foamable resin bead filling machine according to claim 1, wherein the relative positions of the protrusions 30 and the annular grooves 31 are determined. 4. The length of the rod 17 is determined so that the front end surface of the plunger 22 and the front edge of the jet beak 23 are on the same plane when the piston 13 is in the advanced position. The described expandable resin bead filling machine. 5. The foamability according to claim 4, wherein the dimensions of the inner cylinder 21 are determined so that the distance between the front edge of the jet beak 23 and the front end of the inner cylinder 21 is substantially equal to the stroke of the piston 13. Resin bead filling machine.