JP2003063471A - Gas-liquid separator for fuel tank, and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a gas-liquid separator for a fuel tank in simple constitution and at low cost with reduced manhours for brazing. SOLUTION: A pair of pipes are manufactured by cutting a pipe of a prescribed size in a set length, each cut pipe is developed on one end side, and the pipe is bend-worked to be formed into a semi-circular pipe P. Communication holes a and b and an insertion hole s are formed by piercing at prescribed positions in the pipe P formed by bend work, and the pipes P are combined with each other to form a circular form. Stays for installation onto the fuel tank is installed to form a doughnut-shaped separator main body 10. On this separator main body 10, a breather pipe 12 to be communicated with a hollow 14 is jointed by brazing or welding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-liquid separator for a fuel tank for a vehicle such as a motorcycle and a manufacturing technique thereof.

[0002]

2. Description of the Related Art Conventionally, gas-liquid separators such as Japanese Patent No. 2696279 proposed by the present applicant have been known as gas-liquid separators for fuel tanks for vehicles such as motorcycles. When manufacturing the gas-liquid separator 50 as shown in FIG. 7, as shown in FIG. 8, a pair of upper and lower press-formed products 51a and 51b are formed, and the outer peripheral flange f and the inner peripheral flange g of each press-formed product 51a and 51b are formed.
After the doughnut-shaped separator main body 51 is formed by joining by brazing or the like, a breather pipe (not shown) is attached to a predetermined portion. A plurality of attachment pieces h for attaching to the fuel tank are provided on the inner peripheral portion of the press-formed product 51a on one side.

[0003]

However, in the gas-liquid separator as described above, the upper and lower press-formed products are superposed, and the entire surface is joined by brazing or the like so as to maintain the airtightness. At the same time as it takes a lot of man-hours for brazing and the like, the amount of brazing material and the like used increases, and the upper and lower press dies for molding the respective press-formed products 51a and 51b are required, which reduces the product cost. There was the problem of becoming expensive.

Therefore, an object of the present invention is to make it possible to manufacture an inexpensive gas-liquid separator with a simple structure which does not require man-hours for brazing and the like.

[0005]

In order to achieve the above object, the present invention provides a donut-shaped separator body in which a pair of left and right pipes bent in a semi-circular shape are combined and joined, and a doughnut-shaped separator body for a fuel tank. A plurality of stays for attachment and a breather pipe communicating with the hollow inside of the separator body are configured.

When the doughnut-shaped separator body is formed by combining and joining a pair of left and right pipes that are bent and formed in a semicircular shape as described above, as compared with the conventional case where the entire circumference is joined. As a result, the joint area is reduced and the joint man-hours can be saved. In addition, the upper and lower press dies are not required, and as a result, it can be manufactured at low cost.

In this manufacturing method, a pipe of a predetermined size is cut into a set length to produce a pair of pipes, one end of each cut pipe is expanded, and each pipe is bent. After forming each into a semi-circular shape by forming a pierced hole at a predetermined portion of the bent pipe, combine each pipe to form a small donut-shaped separator body and temporarily attach multiple stays. To do. Then, this small assembly is fixed by brazing or welding, and the breather pipe is brazed or welded to the separator body. The pierce hole is, for example, a communication hole for communicating the hollow inside and the outside of the separator body, an insertion hole for inserting the breather pipe into the separator body, or the like.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the accompanying drawings. Here, FIG. 1 is an explanatory view of a fuel tank in which a gas-liquid separator according to the present invention is mounted, and FIG.
Is an enlarged view of a portion of the fuel tank where the gas-liquid separator is attached, FIG. 3 is a side view of the present gas-liquid separator, FIG. 4 is a bottom view of FIG. 3, FIG. 5 is a flow chart of a manufacturing process of the gas-liquid separator, and FIG. It is a state diagram before joining a pipe.

The gas-liquid separator for a fuel tank according to the present invention can reduce the product cost by reducing the joining process and at the same time having a simple structure. The feature is that instead of stacking and joining pressed products, pipes that are bent into a semicircle are combined and joined.

Before describing the gas-liquid separator, the general structure of the fuel tank to which the gas-liquid separator is applied will be described. Fuel tank 1 for motorcycles etc.
As shown in FIG. 1, the upper half-shell body 2 forming the upper surface side of the tank and the lower half-shell body 3 forming the lower surface side are joined together in a liquid-tight manner by welding or the like. The lower half-shell 3 is formed in such a manner that its central portion is recessed upward so that it can be mounted so as to straddle the upper portion of a frame pipe (not shown). The fuel injection port 4 is formed.

A saucer-shaped mouthpiece 5 as shown in FIG. 2 is attached to the fuel inlet 4, and a gas-liquid separator 6 of the present invention is attached around the mouthpiece 5.
The gas-liquid separator 6 has a function of keeping the pressure in the tank constant by allowing the air in the tank to escape to the outside when the internal pressure increases so that the pressure in the tank does not fluctuate due to changes in the temperature. .

By the way, the bottom surface of the mouthpiece 5 is provided with an inclination, and an opening 5a for supplying fuel into the tank is formed at a substantially central portion, and the cylindrical portion 7 is formed in the opening 5a.
And a connection port 5f for connecting the overflow pipe 8 is provided at a lower portion of the inclined surface of the bottom surface of the base 5. When the fuel is supplied to the fuel tank 1, the refueling gun is inserted from the tubular portion 7 of the opening 5a to refuel, and when the fuel level exceeds the upper surface of the tubular portion 7, the overflowed fuel is discharged from the overflow pipe 8. I am trying to do it.

The gas-liquid separator 6 has a doughnut-shaped separator body 10 as shown in FIGS. 3 and 4, and a plurality of stays 11 joined to the separator body 10.
And a breather pipe 12 which is joined to the separator body 10 and extends downward. The stay 11 is adapted to be attached to the bottom surface of the mouthpiece 5 shown in FIG. Is inserted into the hollow portion 14 through an insertion hole s formed on the lower surface side of the separator body 10, and the upper end portion forms a slight gap e (FIG. 2) with respect to the inner surface of the upper wall of the protruding portion 10t of the separator body 10. It is held and fixed.

The upper and lower surfaces of the separator body 10 are provided with communicating holes a and b at predetermined positions. The communicating holes a and b allow the inside of the hollow portion 14 of the doughnut-shaped separator body 10 and the inside of the fuel tank 1. And the inside of the hollow portion 14 communicates with the outside of the fuel tank 1 by the breather pipe 12. Further, the height position of the gap e between the inner surface of the protruding portion 10t of the separator body 10 and the breather pipe 12 is set to a position higher than the upper surface of the tubular portion 7 of the base 5, as shown in FIG. For this reason,
Even when the fuel is completely filled up to the upper surface of the tubular portion 7, the gap e portion faces the air layer, and the breather pipe 12
The air pressure in the fuel tank 1 can be adjusted by.

Next, a method for manufacturing the gas-liquid separator 10 will be described with reference to FIGS. First, a pipe having a predetermined thickness and material is prepared, and the pipe is cut into a set length to form a pair of pipe materials.

Next, one end of each of the cut pipe materials is expanded so that the pipe diameter before the expansion can be fitted into this expanded portion. Next, this pipe material is subjected to bender processing to form a pair of semicircular pipes P as shown in FIG.

When the semi-circular pipes P are bent and formed, piercing holes serving as communication holes a and b are formed near one end of each pipe P. At this time, the communication holes a and b of the pipes P are formed in a direction in which they are in the vertical direction when assembled, and in which the phases of the two are different by 180 degrees from each other. In addition, an insertion hole s through which the breather pipe 12 can be inserted is formed on the lower surface side of the pipe P on one side, and a projection portion protruding upward is provided on the upper surface side facing the insertion hole s. Form 10t. Then, these pipes P are plated with, for example, electroless Ni.

Next, the other end sides of the pipes P are fitted to the expanded portions of the pipes P so as to form a donut shape, and the separator body 10 is assembled into a small set.
A plurality of stays 11 are provided at predetermined positions on the separator body 10.
Is temporarily attached, and thereafter, is permanently attached by brazing in the furnace.
After that, the breather pipe 12 is inserted into the insertion hole s, and brazing is performed while leaving a gap e between the insertion tip and the inner surface of the protrusion 10t. Finally, an airtight inspection is performed to complete the product.

When the separator body 10 is molded by the above-described method, the press areas above and below the plate materials are not superposed and bonded as in the conventional case, so that the bonding area is greatly reduced and the airtightness is maintained. While facilitating the work of joining while reducing the number of joining steps,
The amount of brazing material used can be reduced. In addition, there is no need for a press die, and it can be manufactured at low cost.

The present invention is not limited to the above embodiment. Those having substantially the same configurations as those described in the claims of the present invention and exhibiting the same operational effects belong to the technical scope of the present invention. For example, the fuel tank to which the present gas-liquid separator is applied is not limited to that for motorcycles, and the position and number of stays 11 are also examples.

[0021]

As described above, in the gas-liquid separator for a fuel tank according to the present invention, a donut is formed by combining a pair of left and right pipes bent in a semi-circular shape and attaching a plurality of stays thereto. -Shaped separator body is formed, and the breather pipe that communicates with the hollow inside of the separator body is attached, so there is no need to press-mold as in the past, and the joining area is greatly reduced compared to the past, and the number of joining steps Can be omitted. As a result, it can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is an explanatory view of a fuel tank to which a gas-liquid separator according to the present invention is attached.

FIG. 2 is an enlarged view of a gas-liquid separator mounting portion of the fuel tank.

FIG. 3 is a side view of the gas-liquid separator.

FIG. 4 is a bottom view of FIG.

FIG. 5 is a flow chart of a gas-liquid separator manufacturing process.

FIG. 6 is a state diagram before joining the pipes.

FIG. 7 is a conventional view of a gas-liquid separator, (a) is a plan view,
(B) is an explanatory view seen from the side

FIG. 8 is an explanatory view of a conventional separator body coupling structure.

[Explanation of Codes] 1 ... Fuel tank, 6 ... Gas-liquid separator, 10 ... Separator body, 11 ... Stay, 12 ... Breather pipe, 14 ...
Hollow part, P ... Pipe.

Claims (2)

[Claims] 1. A doughnut-shaped separator body in which a pair of left and right pipes bent in a semicircular shape are combined and joined, a plurality of stays for attaching the doughnut-shaped separator body to a fuel tank, and a hollow of the separator body. A gas-liquid separator for a fuel tank, comprising a breather pipe communicating with the inside. 2. A step of cutting a pipe of a predetermined size into a set length to produce a pair of pipes, a step of expanding one end side of each of the cut pipes, and a bending process of each pipe. Forming each into a semi-circular shape, forming a pierced hole in a predetermined portion of the bent pipe, combining each pipe, assembling a donut-shaped separator body into a small set, and temporarily attaching multiple stays A method for producing a gas-liquid separator for a fuel tank, which comprises the steps of: applying a brazing or welding process to this subassembly, and brazing or welding a breather pipe to the separator body.