JPH049942B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention mainly relates to a method of manufacturing a taper stopper for a gas tank.

(Prior Art) Conventionally, as shown in FIGS. 1 to 3, a conventional method for manufacturing this type of taper stopper is to form a passage hole c opening in a peripheral surface b in a cylindrical columnar body a. A method is known in which a product is obtained by performing a hole drilling process and then a taper process to form a tapered surface d by cutting the circumferential surface b, and the product is then, for example, as shown in FIG. As a result, the entire body is fitted into the main body e, resulting in a gas-like structure.

(Problems to be Solved by the Invention) However, according to such a manufacturing method, the cross-sectional shape of the opening end of the passage hole c is as shown in FIG. An acute-angled convex portion is obtained as shown by the chain line in the figure, which is then removed by cutting with a blade f during the taper process.
The state shown by the solid line in the figure is obtained, but in this case, a burr h extending forward in the cutting direction is likely to be formed on the mouth edge g, and this burr causes grease clogging, making gas control difficult. In order to do so, it must be removed manually or otherwise, which is unavoidably troublesome.

(Means for Solving the Problems) The object of the present invention is to provide a method that does not cause such inconvenience, that is, a method that does not generate burrs. In a device in which a taper plug is obtained by performing a drilling process to form a passage hole that opens and then a taper process to form the peripheral surface into a tapered surface, the opening of the passage hole is formed prior to the taper process. The mouth edge on at least one side in the circumferential direction of the end is chamfered to form the mouth edge into an obtuse-angled convex portion.

(Example) An example of the present invention will be described with reference to attached drawings. 6th
Figures 12 to 12 show one example, and numeral 1 indicates a cylindrical columnar body.
The product is manufactured by performing a drilling process to form a passage hole 3 that opens into the surface, and then a taper process to form a tapered surface 4 by cutting the circumferential surface 2. This point is particularly different from conventional products. No. In the drawings, reference numeral 5 indicates a cutting tool for cutting the outer periphery for the taper process.

According to the present invention, prior to the taper process, the opening edge 6 of at least one side in the circumferential direction of the opening end of the passage hole 3 is chamfered to form the opening edge 6 into an obtuse-angled convex portion. It was made to form.

To explain this in detail, in the illustrated example, a rotary type cutter 7 as shown in FIG. The resulting chamfered portion 8 has a rectangular outline as shown in FIG. 8 as a whole, and its cross-sectional shape is, for example, as shown in FIG. The portion 6 is chamfered on both one side and the other side by the cutter 7 to obtain an obtuse-angled convex portion as shown in the figure, so that during the subsequent taper processing by the cutter 5, especially on the circumferential surface. Regarding the mouth edge 6 on the right side,
There is no occurrence of burrs that tend to occur with conventional acute-angled convex portions.

In this case, if the machining allowance h ₁ due to the chamfering process and the machining allowance h ₂ due to the taper process are matched correctly, the mouth edge 6 will be removed from its inner side at the product stage as shown in the figure. Although a good sealing property can be obtained in the acute-angled convex portion 6a, it is not necessarily easy to obtain this over the entire circumference of the opening end. That is, the cutting allowance h ₂ due to the taper process gradually increases from the root side to the tip side along the length direction of the columnar body 1, whereas the cutting allowance h ₁ due to the chamfering process increases gradually from the root side to the tip side.
is uniform along the length direction, and thus it is impossible to always match the facing allowance h ₁ h ₂ at each point in the length direction.In order to eliminate such inconvenience as much as possible, It is conceivable to use the cutter 7 shown in FIG. 14, for example, and to increase the cutting allowance _h1 in advance toward the tip end. Changes in the chamfered portion 8 in this case are as shown in FIGS. 15 to 17, for example.

Furthermore, it is also effective to gradually reduce the cutting h ₁ from the central part in the longitudinal direction of the opening end toward the front and rear directions. use. Changes in the chamfered portion 3 in this case are as shown in FIGS. 19 and 20, for example.

Furthermore, the cutter 7 can be made as shown in FIG. 22, and in this case, the chamfered portion 8
The changes are as shown in FIGS. 23 to 25, for example. Incidentally, if only sealing performance is required, the other part may be cut largely as shown in FIG.

(Function) To explain its function, for example, it is clearly shown in FIG. The mouth edge portion 6 is formed from a conventional acute-angled convex portion to an obtuse-angled convex portion in preparation for subsequent taper processing, and no burrs are generated on the mouth edge portion 6 during taper processing.

(Effects of the Invention) As described above, according to the present invention, it is possible to eliminate the occurrence of burrs that are likely to occur on the edge of the opening end of the passage hole, and the work is sufficient to simply perform chamfering in advance. It is simple and has the effect of producing excellent products at low cost and with high efficiency.

[Brief explanation of drawings]

1 to 5 are explanatory diagrams of a conventional example, and FIGS. 6 to 9 are explanatory diagrams of an example of the method of the present invention.
Figure 0 is a cutaway side view of Figure 9, Figure 11 is a cross-sectional side view of Figure 8.
An enlarged sectional view taken along the line XI-XI, Fig. 12 is a side view of one side of the cutter used, Fig. 13 is an enlarged sectional view showing a modification of Fig. 11, and Fig. 14 shows the other cutters used. Side view of an example of FIGS. 15 and 16
The figure is an explanatory diagram of changes in the chamfered part, Figure 17 is a cross-sectional side view of Figure 15, Figure 18 is a side view of another example of the cutter, and Figures 19 and 20 are the obtained surfaces. An explanatory diagram of changes in the chamfered part, Fig. 21 is a cutaway side view of Fig. 19, Fig. 22 is a side view of another example of the cutter, and Figs. 23 and 24 show changes in the chamfered part obtained. FIG. 25 is a cutaway side view of FIG. 23. 1... Column body, 2... Surrounding surface, 3... Passage hole, 4
... Tapered surface, 6 ... Mouth edge, 8 ... Chamfered portion.

Claims (1)

[Claims] 1. A tapered stopper is obtained by subjecting a cylindrical columnar body to drilling to form a passage hole opening on the circumferential surface, and then tapering to form the circumferential surface into a tapered surface. , a taper plug comprising, prior to the tapering process, chamfering the opening edge of at least one side in the circumferential direction of the opening end of the passage hole to form the opening edge into an obtuse-angled convex part; manufacturing method.