JPH0788859A - Raw material filling machine - Google Patents

Abstract

PURPOSE:To provide a foam molding raw material filling machine capable of efficiently filling a mold with a raw material by preventing the generation of the clogging of the gap between a piston and the inner wall of a raw material supply pipe with the raw material and reduced in the stroke of a cylinder. CONSTITUTION:In a foam molding raw material filling machine wherein a piston 4 opening and closing the opening part 2 for filling a foaming mold with a pre-foamed granular raw material by the operation of a cylinder is provided to the rear of a raw material supply pipe 1 having the opening part 2 provided to the leading end thereof, a nozzle pipe 15 which becomes smaller in its inner diameter toward the leading end thereof and injects air for supplying the raw material toward the gap between the piston 4 and the raw material supply pipe 1 from the rear position of the piston at the time of the return movement of the piston 4 is provided in the raw material supply pipe 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foam molding raw material filling machine capable of efficiently filling a pre-expanded particle raw material into a mold.

[0002]

2. Description of the Related Art Conventionally, in an expanded synthetic resin molding machine using a pre-expanded particle material such as expanded polystyrene products,
A foam molding raw material filling machine provided with a piston for opening and closing the opening by a cylinder operation at the rear of a raw material supply pipe having an opening formed at the tip for filling a pre-expanded particle raw material in a mold for foam molding. It is generally used (for example, see Japanese Utility Model Publication No. 4-3786).

Recently, a piston having a retracted position which is located in the middle of the front portion of the raw material supply pipe instead of the rear end portion of the conventional raw material supply pipe has been shortened and the cylinder has been downsized. However, in the case of such a filling machine, since the pre-expanded particulate material is supplied toward the opening while the piston is stopped in the middle of the material supply pipe, the gap between the piston and the material supply pipe is sharp. However, there is a problem in that the raw material is clogged in this gap portion, called a bridge, and the raw material cannot be efficiently supplied.

[0004]

The problem to be solved by the present invention is to solve the above-mentioned conventional problems, and when the piston is retracted, a gap is formed between the piston and the inner wall of the raw material supply pipe. Completed for the purpose of providing a foam molding raw material filling machine that can fill the raw material efficiently into the mold for foam molding while making it a small device with a small cylinder stroke to prevent the material from clogging. It was done.

[0005]

The raw material filling machine of the present invention made to solve the above-mentioned problems is a raw material having an opening at the tip for filling a pre-expanded particle raw material into a mold for foam molding. In a foam molding raw material filling machine provided with a piston for opening and closing the opening by the operation of a cylinder at the rear of the supply pipe, in the interior of the raw material supply pipe, when the piston is retracted, a piston is provided from a position behind the piston. The present invention is characterized in that a nozzle tube is provided in which the inner diameter for ejecting the air for supplying the raw material toward the gap with the raw material supply tube is gradually reduced toward the tip.

[0006]

The present invention will now be described in detail with reference to the illustrated embodiments. FIG. 1 shows an embodiment of the present invention, in which 1 is a raw material supply pipe having an opening 2 for filling the raw material formed at its tip, and 3 is the same as the raw material supply pipe 1 which is connected coaxially to the rear side thereof. A cylinder having a relatively small stroke for operating a piston 4 that opens and closes the opening 2 is a piston rod, and 6 is a cylinder head. Further, the cylinder 3 is connected to a piston advancing air supply hole 7a for advancing and retreating the piston 4 and a piston retreating air supply hole 7b.

In the embodiment, a raw material flow passage 8 parallel to the axial direction is provided on the outer peripheral portion of the cylinder 3, and the rear end portion of the raw material flow passage 8 communicates with the raw material supply port 9. The cylinder 3 and the raw material flow passage 8 are formed in an integrally formed member 10 formed by, for example, a precision extrusion molding method or a pultrusion molding method using an aluminum alloy block as a base material. By using the integrally molded member 10 having a different structure, the assembling work can be facilitated and the manufacturing cost can be reduced.

A piston 4 is attached to the raw material supply pipe 1.
There is provided a nozzle pipe 15 for ejecting the air for supplying the raw material toward the gap S between the piston 4 and the raw material supply pipe 1 from the rear of the piston 4 when retreating. This nozzle tube 1
Reference numeral 5 denotes a piston 4 and a raw material supply pipe 1 in which the air supplied from the raw material supply air supply hole 13 has the smallest space.
The pre-expanded particles, which are the raw material, are jetted toward the portion of the gap S between the nozzle tube 1 and the nozzle tube 1
5 is that the inner diameter is gradually reduced toward the tip,
This point is a characteristic configuration of the present invention. The pressure of the air ejected from the nozzle tube 15 is thereby sufficiently increased so that the raw material can be efficiently charged into the mold in a short time.

Further, if a thin portion 1a for expanding a gap with the piston 4 is formed in a portion of the inner wall of the raw material supply pipe 1 surrounding the piston 4 when the piston 4 is retracted, it is most preferable. Piston 4 with a narrow space
The distribution of the raw material in the gap S between the material and the raw material supply pipe 1 becomes extremely smooth, and the filling efficiency can be further improved. Further, a portion corresponding to the raw material inlet 8a at the rear portion of the raw material supply pipe 1 of the piston rod 5 is a small diameter portion 5a,
If the connecting portion between the small-diameter portion 5a and the piston rod 5 is formed as a gentle taper portion 5b, the resistance of the piston rod 5 can be made extremely small when the raw material flows into the raw material supply pipe 1 through the raw material inlet 8a. Therefore, the filling efficiency can be further improved.

[0010]

With this structure, the cylinder 2 is actuated to move the piston 4 forward and backward to move the opening 2
The nozzle pipe 15 which is gradually opened and closed as the inner diameter of the piston 4 retreats when the opening 2 is opened from the rear position of the piston 4 toward the gap between the piston 4 and the raw material supply pipe 1. Air for raw material supply is jetted from the tip of
As a result, the raw material sucked from the raw material supply port 9 through the raw material flow passage 8 into the raw material supply pipe 1 is air-supplied into the mold by this jet flow. Even if the retracted position of the piston 4 is located in the middle of the passage, the raw material forms a bridge between the piston 4 and the inner wall of the raw material supply pipe 1 because the tip of the nozzle pipe 15 is at the rear position of the retracted piston 4. As a result, it is possible to reduce the stroke of the cylinder 3 for moving the piston 4 forward and backward without causing the material to be clogged and to downsize the entire apparatus. Moreover, since the nozzle pipe 15 is a special one whose inner diameter is gradually reduced toward the tip as described above, it is ejected from the nozzle pipe 15 toward the gap S between the piston 4 and the raw material supply pipe 1. The air pressure is sufficiently increased, and the raw material is efficiently filled in the mold in a short time.

As shown in the embodiment, the raw material supply pipe 1
In which the thin wall 1a is formed on a part of the inner wall of the piston, the space S between the piston 4 and the raw material supply pipe 1 is the narrowest space S
When the raw material flows into the raw material supply pipe 1, the small diameter portion 5a in which a part of the piston rod 5 is connected by a gentle taper portion 5b can be extremely smoothed. The resistance of the piston rod 5 can be made extremely small, and the filling efficiency can be further improved. As described above, according to the present invention, the required amount of the raw material can be efficiently filled in the mold in a short time, and excellent molding efficiency can be exhibited.

[0012]

As is apparent from the above description, according to the present invention, the cylinder stroke can be shortened to reduce the size of the apparatus, and the raw material for pre-expanded particles can be efficiently foamed in a short time. It can be filled in a mold and can exhibit excellent molding efficiency. Therefore, the present invention, as a raw material filling machine to eliminate the conventional problems,
The areas that contribute to the development of industry are extremely large.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention.

[Explanation of symbols]

 1 Raw material supply pipe 1a Thin part 2 Opening part 3 Cylinder 4 Piston 5 Piston rod 5a Small diameter part 5b Tapered part 8a Raw material inlet 15 Nozzle pipe

Claims (3)

[Claims] 1. A raw material supply pipe (1) having an opening (2) for filling a pre-expanded particle raw material into a mold for foam molding, the opening (2) being operated by a cylinder (3). In a foam molding raw material filling machine provided with a piston (4) for opening and closing 2), the piston (4) is provided inside the raw material supply pipe (1).
Nozzle whose inner diameter for ejecting air for raw material supply toward the gap between the piston (4) and the raw material supply pipe (1) from the rear position of the piston (4) when the piston is retracted is gradually reduced toward the tip. A raw material filling machine having a pipe (15). 2. The piston of the inner wall of the raw material supply pipe (1)
The part of the piston (4) that faces the surroundings when retracting (4)
The thin portion (1a) which widens the gap between
The raw material filling machine described in. 3. The piston (4) of the piston rod (5)
The narrow diameter portion (5a) connected to the raw material inlet (8a) of the raw material supply pipe (1) at the time of retreat of the raw material is formed by a gently tapered portion (5b). Raw material filling machine.