JPS6314972Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a hole saw for making a large circular hole in a workpiece.

[Background Art] When drilling a hole with a hole saw, the circular piece that has been extracted may end up getting into the hole saw. In order to remove this, use the hole saw as shown in Figure 6.
A saw 1 is mounted in a holder 3 fixed to the tip via a mounting base 2, with an extrusion pin 4 biased forward by a spring 5. During the drilling process, the push-out pin 4 moves backward, and after the hole-drilling process is completed, the push-out pin 4 pushes out the piece that has been fitted into the saw 1. However,
Cuttings and dust generated during the drilling process may enter the sliding part between the holder 3 and the ejector pin 4, causing the ejector pin 4 to stop moving, and if the ejector pin 4 remains retracted, As shown in Figure 7,
The sampled piece 10 cannot be ejected from inside the saw 1, and during the next hole drilling process, the sampled piece 10 cannot be ejected from inside the saw 1.
If the hole saw hits the workpiece 11 and the hole saw cannot be drilled, the heat generated at this time will shorten the life of the hole saw, and if the ejector pin 4 remains stuck and does not move, as shown in Fig. 8. As shown, the push-out pin 4 hits the object to be cut, making it impossible to drill the hole.

[Purpose of the invention] The present invention was created in view of the above points, and its purpose is to provide a hole saw equipped with an extrusion pin that can reliably eject the sampled piece that is stuck inside the saw. is to provide.

[Disclosure of the invention] Accordingly, the present invention has an extrusion pin, one end of which protrudes from the front end surface of the holder, arranged so as to be slidable in the axial direction of the holder, in a storage space within a holder to which an annular saw is attached to the front end. The hole saw is equipped with a spring that biases the ejector pin in the projecting direction, the holder is provided with a discharge port that communicates the storage space with the outside, and the ejector pin has an axial hole passing through it in the axial direction. , is characterized by having a plurality of holes connecting the shaft hole and the outer circumferential surface, and dust, etc. that enters the sliding surface of the holder and the ejector pin are removed from the holes and the shaft hole. It is designed to lead to the storage space of the holder through the holder and to be discharged from the discharge port.

The present invention will be described in detail below based on the illustrated embodiment. The illustrated hole saw is for drilling holes in synthetic resin molded products, and the annular saw
The mounting base 2 that holds the holder 3 on the outer periphery
is fixed to the tip of the The extrusion pin 4, which is disposed in the storage space in the tip of the holder 3 and has one end protruding from the tip surface of the holder 3, is attached to the holder 3.
It is slidable in the axial direction, and is biased in the projecting direction by a spring 5 housed in the storage space.

Now, as is clear from FIG. 3, the extrusion pin 4 here has a plurality of long grooves 7 in the axial direction on the outer circumferential surface of the large diameter part that slides on the inner surface of the holder 3, and has a large diameter. A plurality of holes 8 are provided on the outer peripheral surface of the diameter portion and communicate with the shaft hole 9 passing through the extrusion pin 4.
As shown in FIG. 2, the holder 3 is also provided with a plurality of long hole-shaped discharge ports 6 that communicate the outside with the storage space.

Therefore, when drilling holes with this hole saw, even if dust generated during cutting enters the sliding surface between the holder 3 and the ejector pin 4, it will accumulate on the sliding surface. Before the amount of dust becomes large enough to stop the movement of the ejector pin 4, the ejector pin 4 moves backward due to drilling work, and the tip of the ejector pin 4 comes into contact with the workpiece to be cut, causing resistance to rotation. Due to the relative rotation between the holder 3 and the push-out pin 4 caused by the receiving of the dust, the dust enters the hole 8 and the groove 7, and enters the storage space in the holder 3 through the hole 8 and the shaft hole 9 or the groove 7. It is something that invades
The dust that has reached the storage space is then discharged to the outside from the discharge port 6 as the holder 3 rotates. Therefore, the ejector pin 4 does not become stuck due to dust entering the sliding surface, and the ejector pin 4 can reliably eject the extracted piece. This ensures that the ejector pin 4 does not retreat against the spring 5 and interfere with cutting.

In the above embodiment, the groove 7 is formed on the outer surface of the extrusion pin 4.
By providing a groove 7, the sliding resistance between the holder 3 and the push-out pin 4 can be reduced, and dust can be discharged more easily. It may be something that does not have .

[Effects of the invention] As described above, in the present invention, dust and the like that reach the sliding surface between the holder and the ejector pin reach the storage space of the holder through the hole and shaft hole provided in the ejector pin, and Since the ejection pin is ejected from the ejection port of the holder, the sliding surface will not be clogged with dust and the ejector pin will not move, and therefore the ejector pin can always eject the extracted pieces reliably. This eliminates machining errors and reduces life expectancy due to excessive use.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the present invention, Fig. 2 is a front view of the holder shown above, Fig. 3 is a perspective view of the ejector pin shown above, and Fig. 4 is a partial sectional view of the holder and ejector pin shown above. , FIG. 5 is a front view of another example of the extrusion pin, FIG. 6 is a sectional view of a conventional example, and FIGS. 7 and 8 are explanatory views of the same operation, in which 1 is a saw, 3 is a holder, 4 is an extrusion pin, 5 is a spring, 6 is a discharge port,
8 indicates a hole, and 9 indicates a shaft hole.

Claims (1)

[Scope of utility model registration request] An ejector pin, one end of which protrudes from the distal end surface of the holder, is disposed in a storage space within the holder to which the annular saw is attached to the distal end so as to be slidable in the axial direction of the holder, and the ejector pin is attached in the protruding direction. The hole saw is equipped with a biasing spring, the holder is provided with a discharge port that communicates the storage space with the outside, and the ejector pin has a shaft hole that penetrates in the axial direction;
This hole saw is equipped with a plurality of holes connecting this shaft hole and the outer peripheral surface.