JP2597538B2 - Drilling tool casting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for casting a drilling tool used for excavating rock or the like.

[0002]

2. Description of the Related Art Conventionally, some excavation tools such as ripper points attached to the tip of a shank such as a ripper and used for excavation of rock are manufactured by casting. Conventionally, when a drilling tool is manufactured by casting, a feeder c is provided in a recess b of the drilling tool a as shown in FIG. 3, or a feeder c is provided on the outer surface of the drilling tool a as shown in FIG. And casting.

[0003]

However, when the feeder c is provided in the recess b of the excavating tool a as in the former case, the trace of removal of the feeder d remains in the recess b as shown in FIG. There was a problem that many man-hours were required to remove this. Further, in the case where the feeder c is provided on the side surface of the excavating tool a as in the latter, since the feeder removal mark d remains on the side surface of the excavating tool a, the appearance of the product is impaired and the space of the feeder in the mold is reduced. Is required, resulting in problems such as an increase in the size of the mold. SUMMARY OF THE INVENTION The present invention has been made for the purpose of improving the above disadvantages, and an object of the present invention is to provide a method for casting a drilling tool which does not require removal of a riser removal trace.

[0004]

In order to achieve the above object, according to the present invention, the lower end of the feeder is connected to a concave portion which is one step lower than the inner bottom of the concave portion provided in the excavating tool body. Forming a riser, casting the drilling tool body by pouring from the riser, and removing the riser from the connection between the lower end of the riser and the concave recess after casting. Since the trace of removal of the riser generated when the riser is removed is generated in the recess which is one step lower than the inner bottom of the recess, the trace of removal of the riser does not interfere with the adapter during use.

[0005] This eliminates the need for man-hours for removing traces of feeder removal, so that excavating tools can be provided at low cost. Also, since the feeder is provided in the recess, the trace of removing the feeder is not exposed on the surface of the drilling tool body,
The appearance of the product is good, and no extra space is required for providing a feeder in the mold, so the mold can be small and compact.
The weight can be reduced.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
This will be described in detail with reference to FIG. In these figures, reference numeral 1 denotes an excavating tool main body cast by the method of the present invention, which has a substantially triangular prism shape, has a sharp distal end side, and has a shank distal end inserted into the base end side through an adapter. A recess 1a is formed, and pin insertion holes 1b are formed on both side surfaces of the recess 1a.

A recess 1c is formed at the bottom of the recess 1a so as to be one step lower than the bottom of the recess 1a. A feeder 2 provided in the recess 1a at the time of casting is formed in the recess 1c. 1d is left.

Next, a method of casting the excavating tool main body 1 will be described. When molding a mold (not shown) used for casting, as shown by an imaginary line in FIG. The feeder 2 is formed in the lower end of the feeder 2
The bottom surface of the concave portion 1c, which is formed one step lower than the bottom portion a, communicates with a cavity (not shown) in the mold.

The feeder 2 is placed in the mold formed as described above.
After the molten metal is poured, the cavity in the mold is filled with the molten metal, and after the solidification of the molten metal, the excavating tool body 1 is taken out from the mold. In this case, a trace of removal of the feeder remains at the connection portion, but remains in the recessed portion 1c, which is one step lower than the bottom of the recessed portion 1a. The trace 1d of the riser does not interfere with the adapter, and the work of removing the trace 1d of the riser after the mold becomes unnecessary, so that the man-hour required for the removal can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a drilling tool cast according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an explanatory view showing a conventional casting method.

FIG. 4 is a sectional view of a drilling tool cast by a conventional casting method.

FIG. 5 is an explanatory view showing a conventional casting method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Drilling tool main body 1a ... Concave part 1c ... Concave concave part 1d ... Trace of removal of feeder 2 ... Feeder.

Claims (1)

(57) [Claims] 1. A recess 1a provided in a drilling tool body 1.
The feeder 2 is formed so that the lower end of the feeder 2 is connected to the recessed portion 1c which is one step lower than the inner bottom of the excavation tool. A method for casting a drilling tool, wherein the feeder 2 is removed from a connection between the lower end of the feeder 2 and the concave portion 1c.