JPH0382629A - Fuel tank and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a fuel tank with a bottom face not damaged when mounted on the ground by pressing and arranging lower synthetic resin films on a synthetic resin reinforcing plate heated and inserted in advance at the portion corresponding to the bottom frame of the fuel tank in a hollow mold section. CONSTITUTION:In manufacturing a fuel tank 17 of a portable engine for a brush cutter, a synthetic resin reinforcing plate 39 heated in advance is inserted into the hollow mold section 27 of a lower mold 25 at the position corresponding to the bottom face of the fuel tank 17. Multiple synthetic resin films 35 and 37 heated in advance are arranged between an upper mold 23 and the lower mold 25 at the position of a split plane 29, and edge sections are pressed and pinched. Air is injected by pressure between synthetic resin films 35 and 37 by an injection needle 31, synthetic resin films 35 and 37 are pressed to the inner face of the hollow mold section 27 and cooled, solidified, and molded. The upper mold 23 and the lower mold 25 are separated, and an inside molding is taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel tank for a portable engine such as a brush cutter and a method for manufacturing the same.

Conventionally, this type of fuel tank was made of a synthetic resin membrane and was mounted below the engine, so when the engine was mounted on the ground, it would come into contact with the bottom of the fuel tank, causing damage to the fuel tank. The bottom surface is susceptible to damage such as cracks, and for this reason, legs for contacting the ground are separately manufactured and fixed to the bottom surface, making the structure complex and requiring many manufacturing steps, making it difficult to manufacture the fuel tank. This was hindering efficiency.

Furthermore, conventionally, fuel tanks made of synthetic resin were heated and formed by filling a thermoplastic powder synthetic resin film into a mold, which made it difficult to form a hollow body. They formed shells of the same shape and glued them together to form a hollow body. For this reason, the work efficiency was poor and the fuel tank was expensive, making it unsuitable for use as a fuel tank for small engines. To address this drawback, fuel tanks have been manufactured by blow molding, but with this method, the front surface of the tank is uniform and the bottom surface in contact with the ground is easily damaged, and it is difficult to install the fuel tank below the engine. In other words, in this method, a tubular heat-weldable cloth-like synthetic resin film is flattened into upper and lower layers, which are heated in advance. The membrane is sandwiched between upper and lower molds that have a hollow mold part inside, the edges are crimped, air is forced between the upper and lower membranes, and the membrane is pressed against the inner surface of the hollow mold part. It is cooled, solidified and molded. In this case, since the entire circumference of the tank is molded from the same tubular material, the entire circumference of the tank has the same wall thickness.

The present invention provides a fuel tank above ground by attaching a lower synthetic resin membrane to a reinforcing plate made of synthetic resin that has been heated and inserted in advance in a portion of the hollow mold part corresponding to the bottom of the fuel tank. The aim is to easily manufacture a fuel tank whose bottom surface will not be damaged even if it is placed on the ground.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a brush cutter, in which an engine 7 and a sludge receiver 5, which rotatably supports a rotary blade 3, are connected by a connecting rod 9.

11 is a handle fixed to the connecting rod 9; 13 is the connecting rod 9;
and a hanger suspended from engine 7, and the shoulder strap is band 15.
are connected. 17 is a fuel tank mounted below the engine 7; one is a cap for the inlet 21 of the fuel tank 17;

Reference numerals 23 and 25 denote an upper mold and a lower mold, each of which has a hollow mold part 27 having a shape corresponding to the outer shape of the fuel tank 17, and is divided by a dividing plane 29 that includes the center line of the injection port 21. 3
Reference numeral 1 denotes an injection needle inserted into the split surface position, which communicates with the air pipe 33 and injects air. Reference numerals 35 and 37 designate an upper membrane and a lower membrane which are made by flattening a cloth-like synthetic resin membrane formed into a tubular shape. Reference numeral 39 denotes a reinforcing plate, which is made by cutting this tubular synthetic resin membrane into an appropriate length and making it double layered flat. - In the above embodiment, the brush cutter 1 is used to cut grass, etc. on the ground with the rotary blade 3 rotated by the engine 7, with the shoulder strap 15 hung on the shoulder of the worker and the handle 11 held with both hands. It is something that performs work. When the brush cutter 1 is placed on the ground, the position of the connecting rod 9 near the rotary blade 3 is supported by a stand (not shown), and the engine 7 is mounted on the fuel tank 17.
Place it with the bottom side touching the ground. When molding the fuel tank 17, a reinforcing plate 3 made of a preheated synthetic resin film is used.
9 into the hollow mold part 27 of the lower mold 25, and the fuel tank 17
The upper mold 23 is inserted into a position corresponding to the bottom surface of the upper mold 23, and then a preheated synthetic resin film 35, 37 is placed on the dividing surface 29.
and the lower mold part 25 , the edges are crimped and clamped, and when air is injected between the synthetic resin films 35 and 37 using the injection needle 31 , the synthetic resin films 35 and 37 are formed on the inner surface of the hollow mold part 27 . It is pressed, cooled, solidified, and molded. This upper mold 2
3. The lower mold 25 is separated to take out the molded product inside, and the reinforcing plate 39 is pressed onto the synthetic resin membrane 37, making it possible to provide a thicker bottom surface of the fuel tank 17.

Since the present invention is a method for manufacturing a fuel tank as described in the claims, it is possible to increase the wall thickness of the bottom surface in contact with the ground, and also facilitates manufacturing and improves work efficiency in manufacturing the fuel tank. It is something that can be improved.

Note that the present invention is not limited to the above-described embodiments, and can be implemented in other embodiments. Also,
The reference numerals shown in the claims do not limit the technical scope of the present invention.

[Brief explanation of drawings]

FIG. 1 is a perspective explanatory view of a brush cutter, and FIG. 2 is a side cross-sectional explanatory view of one embodiment of the present invention. (Explanation of symbols representing main parts of drawings) 23... Upper mold 25... Lower mold 27... Hollow mold 35
．． 37...Synthetic resin membrane 39...Reinforcement plate

Claims (2)

[Claims] (1) The cloth-like synthetic resin membranes 35 and 37 stacked one above the other are heated in advance, and the edges are crimped using the upper and lower molds 23 and 25, which form a hollow mold part 27 in the shape corresponding to the fuel tank inside. , and pressurize air between the upper and lower synthetic resin membranes 35 and 37 to form a shape that corresponds to the hollow mold part 27, and the hollow mold part 27 to correspond to the bottom surface of the fuel tank. The fuel tank is characterized in that the lower synthetic resin membrane 37 is pressure-bonded to a reinforcing plate 39 made of synthetic resin that has been heated and inserted in advance. (2) The cloth-like synthetic resin films 35 and 37 stacked one above the other are heated in advance, and the edges are crimped and clamped by the upper and lower molds 23 and 25 that form the hollow mold part 27 inside. Air is pressurized between the synthetic resin membranes 35 and 37 to form the hollow mold part 2.
7, and the hollow mold part 2
7. A method for manufacturing a fuel tank, characterized in that the lower synthetic resin membrane 37 is crimped onto a reinforcing plate 39 made of synthetic resin that has been heated and inserted in advance into a portion corresponding to the bottom surface of the fuel tank. .