JPS6117021A - Plug fixing method of oil level gage - Google Patents

Abstract

PURPOSE:To make it possible to mold a plug in a specified shape, by compressing the connecting part of a mandrel and an inserting rod by pairs of molding pins in the direction of the diameter, fixing the part immovably in a molding die, and injecting melted rubber in the molding die under this state. CONSTITUTION:The connecting part of a mandrel 8 and an inserting rod 1 of an oil level gage is put in a molding die, and the die is closed. In the molding hole, molding pins (b) and (b) at the front end part compress the outer surface of the inserting rold 1. Molding pins (a) and (a) at the central part compress the outer surface of the coupling part of the inserting rod 1 and the mandrel 8. Molding pins (c) and (c) at the rear end part compress the outer surface of the mandrel 8. Those parts are compressed in the direction of the diameter, and the connecting part is immovably fixed in a vacuum attitude. Under this state, melted rubber is injected in the molding hole. The connected part is not deflected by the injecting pressure. A plug 10 is molded on the outer surface of the connecting part and fixed. Thus the deflection of the connecting part due to the injecting pressure at the time of the injection of the melted rubber into the molding die can be prevented, and the plug can be molded into a specified shape.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing an oil level gauge suitable for insertion into a bent guide tube, and in particular to a method for manufacturing an oil level gauge suitable for insertion into a bent guide tube. Regarding the method of fixation.

Problems to be Solved by the Invention ``In recent years, as engine control mechanisms have become more complex, various devices have been placed inside the engine room of automobiles, making the space narrower. In many cases, guide tubes for use with equipment are bent so as not to interfere with surrounding equipment, and in order to insert into such bent guide tubes, as shown in Figure 1, a flat steel wire 2 is installed. is tightly wound spirally to form a long wire insertion rod 1 having appropriate flexibility and elastic restoring force, and a gauge piece 3 made of a steel plate that is immersed in oil is attached to the tip of the insertion rod 1, and its widened portion is Attach it with a cap 5 having an inward flange 6 that is hooked on the insert rod 1, and insert the shaft 8 at one end of the handle 7, which is a curved round steel wire, into the hollow rear end of the insertion rod 1 and swage it. The outer periphery of the connecting part between the mandrel 8 and the insertion rod '1 is provided with a stepped seal part 11 that fits tightly into the guide tube and comes into contact with the edge of the guide tube to regulate the insertion depth. An oil level gauge to which a rubber plug 10 consisting of a stopper part 12 is fixed has been developed.

By the way, in order to fix the plug 10 described above, the mandrel 8
The connecting part of the insertion rod 1 was placed in a mold, and molten rubber was injected into the mold and solidified.

Generally, a method is adopted in which the connecting part is bent by the injection pressure of the rubber, and it is integrated with the plug 10 in the bent position, making the overall length of the gauge shorter than the predetermined dimension. Or, the gap between the flat steel wires 2 caused by the bending may become clogged with rubber, and conversely the overall length of the gauge may become longer, resulting in variations in the dimensions of the gauge. Part of i is flat steel wire 2
There was a problem in that the plug 10 could not be formed into a predetermined shape because it entered the hollow of the insertion rod 1 through the gap between the plugs.

The present invention has been completed in view of the above points, and provides a method for fixing a plug for an oil level gauge, which allows the dimensions of the gauge to be made uniform and also enables the plug to be reliably molded into a predetermined shape. The purpose is to provide.

EXAMPLE Hereinafter, an example of the method of the present invention will be described with reference to FIG.

The mold applied to this example has a molding hole that follows the external shape of the plug 10 inside, and can be divided into two parts, upper and lower. , three pairs of molding pins a, a, b, b, c, and c, each of which protrudes toward the center of the molding hole by a spring force, and whose tips correspond to each other, can slide freely. When the connecting portion of the mandrel 8 and the insertion rod 1 is placed in a mold and the mold is closed, the molding pin b at the front end,
b indicates the outer periphery of the insertion rod 1, molded pins a in the center, a, the outer periphery of the fitting part of the insertion rod 1 and mandrel 8, and molded pins c, c in the rear end, the outer periphery of the mandrel 8. The connecting portions are fixed immovably in a straight position by squeezing them in the radial direction. If molten rubber is injected into the molding hole in this state, the plug 10 will be molded and fixed on the outer periphery of the connecting part without bending due to the injection pressure, and each molding pin will resist the spring force. a
1. After removing b and c, the mold is opened and taken out. Note that two holes 15 are formed in the center and both front and rear ends of the plug 10 after pins a, b, and C are removed, but these holes 15 may impair the function of the plug 10. There isn't.

In addition, the method of the present invention is not limited to the oil level gauge having the structure shown in FIG. 1, but the connecting portion between the insertion rod 1 and the mandrel 8 may be fixed as shown in FIG. The oil level has a structure in which the enlarged diameter hole 18 of the cap 17 is fitted onto the rear end of the insertion rod 1, and the mandrel 8 is inserted into the hollow of the insertion rod 1 through the center hole 19 of the cap 17 and fixed by caulking. The same can be applied to gauges.

Structure and Effects of the Invention As specifically explained in the above embodiments, the oil level gauge plug fixing method of the present invention is a flexible plug fixing method in which a gauge portion is provided at the tip by tightly winding a steel wire in a spiral shape. After forming a long insertion rod with a long wire and inserting a two-handled mandrel into the hollow of the rear end of the insertion rod and fixing it, the connecting part of the mandrel and the insertion rod is placed in a mold. In this oil level gauge plug fixing method, a rubber plug that fits tightly into the end of the guide tube is fixed to the outer periphery of the connecting portion by injection molding, in which the connecting portion is radially pinched with a pair of molded pins. The gist is to fix the molten rubber immovably within the mold and inject the molten rubber into the mold in such a state, and when the molten rubber is injected into the mold, the injection Since the connection part is prevented from bending due to pressure, the connection part remains bent and is integrated with the plug, shortening the overall length of the gauge, or the gap between the steel wires caused by the bending becomes clogged with rubber. The gauge can be manufactured to uniform dimensions without increasing the overall length, and since rubber does not enter the hollow part of the insertion rod through the gaps between the steel wires, the rubber is fixed around the outer periphery of the connection part. It is possible to reliably fill the plug in the specified amount, and to reliably mold the plug into a predetermined shape.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an example of an oil level gauge manufactured by applying the method of the present invention, and FIG. 2 is a partial front view showing another example. 1: Insert rod 2: Flat steel wire 3: Gauge piece 7: Handle 8
: Mandrel 10 nib lugs a, b, c: Molded pins

Claims (1)

[Claims] A long flexible insertion rod with a gauge section at the tip is formed by closely winding steel wire in a spiral shape, and the handle shaft is inserted into the hollow rear end of the insertion rod. After it is fixed,
In a plug fixing method for an oil level gauge, the connecting portion of the mandrel and the insertion rod is placed in a mold, and a rubber plug that fits tightly into the end of the guide tube is fixed to the outer periphery of the connecting portion by injection molding. , a plug for an oil level gauge, characterized in that the connecting portion is radially clamped by a pair of molding pins to be immovably fixed within the mold, and in this state molten rubber is injected into the mold. Fixing method