JPH0746414Y2 - Magnetic drilling machine center pin - Google Patents

Description

[Detailed Description of the Invention] [Field of Use of the Invention] The present invention relates to a center pin for a magnetic drilling machine, which ensures positioning when a rotary blade of a magnetic drilling machine is used for punching and discharge of a cutting piece (cutting core). .

[Background of the invention]

 The problems of the prior art will be described with reference to FIG.

During drilling, the center pin 4 is pressed by the spring 3,
After the boring, the cutting core 7 is pushed out by the center pin 4 and discharged from the inside of the rotary blade 5. However, as the steel plate 6 becomes thinner, the extruded cutting core 7 tilts inside the rotary blade 5 and becomes clogged inside the rotary blade 5, resulting in poor workability. Further, there is a problem that the blade edge slips and shifts at the start of drilling.

[Purpose of device]

An object of the present invention is to solve the above-mentioned problems of the prior art, to ensure discharge of the cutting core to improve workability, and to prevent side slippage of the cutting edge to increase safety.

[Outline of the Invention] The present invention relates to improvement of a center pin of a magnetic drilling machine, in which the cutting core is prevented from tilting by pushing the cutting core at the outer peripheral portion of the guide sleeve, and a cutting blade is provided on the outer peripheral portion of the guide sleeve. It is devised to prevent the lateral displacement of the rotary blade by projecting.

[Example of device]

 An embodiment of the present invention is shown in FIGS.

At the lower end of the center pin 4, a pin 4d pressed by a spring (A) 4c is held by a guide sleeve 4b. The guide sleeve 4b is attached to the center pin body 4a with a screw or the like.

As shown in FIG. 1, the boring positioning is performed and the boring is started.

Since the center pin 4 is pressed by the spring 3, it rotates together with the spindle 1. The cutting blade portion 8 provided on the outer peripheral portion of the tip of the guide sleeve 4b bites into the surface of the steel plate 6 while rotating. When the bite amount advances to some extent, the contact area increases, and the bite amount stops. That is, the rotation of the center pin 4 is stopped. In this state, the positioning on the steel plate 6 is perfectly performed, and the lateral displacement at the start of drilling can be reliably prevented.

As shown in FIG. 2, after the boring is completed, the cutting core 7 is pushed out by the outer peripheral cutting edge portion 8 of the guide sleeve 4b, so that the cutting core 7 can be reliably discharged without inclination.

[Effect of device]

According to the present invention, by attaching the guide sleeve having the cutting edge portion on the lower peripheral portion to the tip of the center pin, the cutting edge bites into the steel plate at the start of drilling to prevent lateral displacement of the rotary blade. After the boring, the cutting core can be reliably discharged without tilting.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part where positioning is performed before the start of perforation by a center pin according to the present invention, and FIG. 2 is a longitudinal sectional view immediately after the perforation. FIG. 3 is a front view showing an example of the shape of the tip of the center pin. FIG. 4 is a longitudinal sectional view showing immediately after punching with a conventional magnetic drilling machine. 1 is a spindle, 2 is a center pin guide, 3 is a spring, 4 is a center pin, 4a is a center pin body, 4b is a guide sleeve, 4c is a spring (A), 4d is a pin, 5 is a rotary blade, 6 is a steel plate, 7 Indicates a cutting core, and 8 indicates a cutting edge portion.

Claims (1)

[Scope of utility model registration request] 1. An electromagnet, a stand attached to the electromagnet, an electric drill attached to the stand so as to be movable up and down, a rotary blade attached to a rotary shaft of the electric drill, and an inside of the rotary shaft. In a magnetic drilling machine consisting of a center pin mounted movably up and down via a spring, a pin mounted movably up and down via a spring at the tip of the center pin, and an outer periphery of the lower end cut on the outer periphery of the pin. A center pin for a magnetic drilling machine that is equipped with a guide sleeve protruding in a blade shape.