JPH0246884B2 - OIRUREBERUGEEJINOPURAGUKOCHAKUHOHO - Google Patents

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,
This invention relates to a method of fixing a rubber plug that tightly fits into the end of a guide tube.

Problems to be solved by the invention In recent years, as engine control mechanisms have become more complex,
As various types of equipment are placed inside the engine compartment of automobiles, the space has become narrower, so the guide tube for inserting the gauge, which protrudes from the oil pan, is often bent to prevent interference with surrounding equipment. In order to insert it into such a bent guide tube, as shown in Fig. 1, a long and slender insert having appropriate flexibility and elastic restoring force is made by tightly winding a flat steel wire 2 in a spiral shape. A rod 1 is formed, and a gauge piece 3 made of a steel plate that is immersed in oil is attached to the tip of the rod 1 with a cap 5 having an inward flange 6 that hooks onto the widened portion 4 of the rod 1. The mandrel 8 at one end of the handle 7, which is a curved round steel wire, is inserted into the hollow space at the rear end and fixed by caulking, and the mandrel 8 and the insertion rod 1
An oil level gauge having a rubber plug 10 fixed to the outer periphery of the connecting part thereof, consisting of a stepped seal part 11 that fits into the guide tube and a stopper part 12 that comes into contact with the end of the guide tube to regulate the insertion depth. was developed.

By the way, in order to fix the above-mentioned plug 10, a method is generally adopted in which the connecting portion of the mandrel 8 and the insertion rod 1 is placed in a mold, and molten rubber is injected into the mold and solidified. Although,
In such a method, the connecting portion is bent by the injection pressure of the rubber, and is integrated with the plug 10 in the bent position, resulting in the overall length of the gauge being shorter than a predetermined dimension, or the flat bar caused by the bending. Rubber gets stuck in the gap between wires 2 and the overall length of the gauge becomes longer, causing variations in gauge dimensions.
Additionally, a part of the rubber injected in a certain amount entered the hollow of the insertion rod 1 through the gap between the flat steel wires 2, which caused the problem that the plug 10 could not be formed into a predetermined shape. .

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 makes it possible to make the dimensions of the gauge uniform and to reliably mold the plug 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 plug 1 inside.
The mold has a molding hole that follows the external shape of the mold, and can be divided into upper and lower halves, and the center of the molding hole is formed by spring force at the center and both front and rear ends of the mold. Three pairs of molded pins a, a,
b, b and c, c are fitted so as to be freely slidable,
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 pins b, b at the front end touch the outer periphery of the insertion rod 1 in the molding hole, and the molding pins a, a is the outer periphery of the fitting part of the insertion rod 1 and the mandrel 8,
Further, the molded pins c and c at the rear end radially press the outer periphery of the mandrel 8, so that the connecting portion is immovably fixed in a straight position. 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. After removing a, b, and c, the mold is opened and taken out. In addition, after removing pins a, b, and c, there are two holes in the center and both front and rear ends of the plug 10.
Although individual holes 15 are formed, these holes 15
The function of the plug 10 is not impaired by this.

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 involves forming a flexible elongated insertion rod with a gauge section at the tip by tightly winding a steel wire in a spiral shape, and forming a flexible elongated insertion rod with a gauge section at the tip, and forming a flexible elongated insertion rod at the rear end of the insertion rod. After fitting the handle's mandrel into the hollow of the part and fixing it, the connecting part of the mandrel and the insertion rod is placed in a mold, and the outer periphery of the connecting part is tightly fitted to the end of the guide tube by injection molding. In a plug fixing method for an oil level gauge in which a rubber plug is fixed, the connecting portion is radially clamped with a pair of molding pins to be immovably fixed in the mold, and in this state, the plug is fixed in the mold. The gist is to inject molten rubber into the mold, and when the molten rubber is injected into the mold, the injection pressure prevents the connection part from bending. This eliminates the possibility of shortening the overall length of the gauge due to being integrated with the plug, or increasing the overall length due to rubber getting stuck in the gap between the steel wires caused by bending, making the gauge uniform in size. In addition, since rubber does not enter the hollow part of the insertion rod through the gaps between the steel wires, the outer periphery of the connection part is filled with the specified amount of rubber, and the plug is shaped into the specified shape. It has the effect of ensuring reliable molding.

[Brief explanation of drawings]

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;
The figure is a partial front view showing another example. 1: Insert rod, 2: Flat steel wire, 3: Gauge piece, 7:
Handle, 8: Mandrel, 10: Plug, a, b, c: Molded pin.

Claims (1)

[Claims] 1. A flexible elongated insertion rod with a gauge section at the tip is formed by closely winding a steel wire in a spiral shape, and a handle shaft is inserted into the hollow rear end of the insertion rod. After the mandrel and the insertion rod are fixed together, the connection part between the mandrel and the insertion rod is placed in a mold, and a rubber plug that is tightly fitted into the end of the guide tube is fixed to the outer periphery of the connection part by injection molding. In the plug fixing method, the connecting portion is radially compressed by a pair of molding pins to be immovably fixed within the mold, and in this state, molten rubber is injected into the mold. How to fix the oil level gauge plug.