JPH0120009B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drill reamer, and more particularly, to a drilling process for making a pilot hole and for finishing the pilot hole formed by this drilling process into a precise surface according to desired dimensions. This invention relates to a drill reamer that can perform the finishing process at the same time.

Conventionally, reamers have generally been suitably used for drilling holes with high precision. That is,
A pilot hole is previously drilled with a drill, and a reamer is passed through the pilot hole to perform precision machining to obtain the desired and correct dimensions. Therefore, in the prior art, at least two steps are inevitably required for precision hole machining: a preliminary hole drilling step using a drill and a precision finishing step using a reamer. For this reason, different equipment is required to perform the work with a drill and reamer for drilling one hole, and since two steps are inevitably performed, the process itself requires a considerable amount of time. Inconveniences have been pointed out. Furthermore, drills used when drilling pilot holes generally have a chisel point at the tip, and therefore, when the workpiece has an slanted surface or a material surface such as a cast surface, When drilling a pilot hole, the tip of the drill slides due to the chisel point, and it has been pointed out that the drill does not grip the workpiece and the pilot hole cannot be drilled in the correct position. .

Therefore, as a result of intensive studies and efforts, the inventors of the present invention alternately formed rough blades for forming at least a pilot hole and finishing blades for reaming in the main body portion, and furthermore, the above-mentioned If at least one relief groove extending widely is formed at the tip of the main body portion to eliminate a chisel point, the desired pilot hole can be drilled with a rough blade when drilling the pilot hole, and Since there is no chisel point, it has good grip on the workpiece, making it easy to start drilling the pilot hole.Moreover, the pilot hole formed by the rough blade can be immediately finished into a precision hole by the finishing blade, so it is short and easy to use. It has been found that the desired holes can be obtained in a timely manner and the various disadvantages mentioned above can be eliminated.

Therefore, an object of the present invention is to unify the two hole-machining processes performed by a drill and a reamer when performing machining to form a hole in a workpiece, and furthermore, when the workpiece has an inclined surface, To provide a drill reamer which has a good grip on a workpiece even when a hole is drilled on its inclined surface, and can therefore easily drill a precise hole at a desired position.

In order to achieve the above object, the present invention provides a drill reamer having a handle part and a cutting part, the drill reamer including three cutting parts at least equally spaced apart, each having a rough cutting edge and a finishing cutting edge; An relief groove is formed between the cutting edges, each of the finishing edges is formed to have a longer radial length than the rough edge, and the tip of the cutting edge on the axial line is The groove is formed so as to be inclined inward as an inclined surface facing the handle, and one of the rough blade relief grooves in the relief groove extends to the center of the tip of the drill reamer so as to substantially exclude the chisel point. It is characterized by being configured so that it exists.

Next, preferred embodiments of the drill reamer according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a drill reamer, and this drill reamer 10 basically has a handle part 1.
2 and a blade portion 14. The handle portion 12 forms a so-called straight shank with a circular cross section, and a flat portion 15 connected to a rotational drive source is formed from the end portion to the center portion. In this case, the blade part 14 has three cutting blade parts 16a, 16b, and 16c formed at equal intervals in the circumferential direction, as can be easily understood from FIG. The blade portion 16a includes a roughing blade 18a for drilling a pilot hole and a finishing blade 20a connected thereto. In addition, the rough blade 18
A relatively shallow relief groove 2 is provided between the finishing blade 20a and the finishing blade 20a.
2a, while the second cutting edge 16b
includes a rough blade 18b and a finishing blade 20b, and a shallow relief groove 22b between the rough blade 18b and the partition blade 20b.
is formed. Furthermore, the third cutting edge portion 16c
includes a rough blade 18c and a finishing blade 20c, and a shallow relief groove 22c similar to that described above is formed between the rough blade 18c and the finishing blade 20c. The escape grooves 22a to 22c are for releasing chips cut by the finishing blades 20a to 20c, respectively.
If the opening degree α of these escape grooves 22a to 22c is selected to be about 40 degrees, the chips can be properly guided to the outside. In this case, as can be easily understood from FIG. 2, the drill reamer 10
The length in the radial direction of the rough edges 18a, 18b, 18c at the tips of is at least the finishing edges 20a, 20b,
Select it so that it is shorter than 20c.

Therefore, a relatively deep relief groove 24a is formed between the finishing blade 20a and the roughing blade 18b, and
A clearance groove 24b is similarly formed between the finishing blade 20b and the roughing blade 18c. Furthermore, finishing blade 20c
Similarly, a deep relief groove 2 is formed between the rough blade 18a and the rough blade 18a.
4c is formed. The relief grooves 24a to 24c
are used to carry out relatively large chips generated by the rough blades 18a to 18c, respectively.

Note that the respective relief grooves 24a, 24b and 24
The tip portion of c extends obliquely at a predetermined angle to the center of the drill reamer 10, and forms notches 26a and 2, respectively.
6b and 26c are formed. The cutting blade portions 16a to 16c constructed in this manner each extend in a spiral direction toward the handle portion 12. In this case, for example, it is preferable to select the twist angle between the cutting edges 16a to 16c and the axis of the drill reamer 10 to be about 35 degrees, which is suitable for ejecting chips.

By the way, in the present invention, the escape groove 24c is formed at its tip 28 by cutting into the center of the drill reamer 10 in a large way so as to eliminate the chisel point of the drill reamer 10.
Unlike the other clearance grooves 24b and 24b, the groove 4c is inclined at an angle of β° with respect to the rake face 30a of the rough cutting edge 18a on the way to being oriented in the central axis direction of the drill reamer 10.

The drill reamer according to the present invention is basically constructed as described above, and its operation and effects will be explained next.

The flat portion 15 is connected to a rotational drive source (not shown),
For example, if they are connected via a chuck or the like, the drill reamer 10 will rotate at a high speed when the rotational drive source is started. Therefore, when the tip of the drill reamer 10 is brought into contact with an inclined workpiece (not shown) and displaced along the axial direction, the tip of the blade 14 starts cutting the inclined surface of the workpiece. That is, the tip 28, which has substantially eliminated the chisel point, easily bites into the inclined surface of the workpiece and cuts a portion thereof. Next, the radially extending ends of the rough blades 18a to 18c, that is,
The rake faces 30a, 30b and 30c substantially begin the cutting process for forming a pilot hole in the workpiece.

As mentioned above, the rough blades 18a to 18c are the finishing blades 2.
Since the diameter is selected to be smaller than 0a to 20c, a hole is formed in the workpiece within the range of the diameter. In this case, the chips generated by this cutting process are transferred toward the handle portion 12 through the spiral grooves of the relief grooves 24a to 24c. As can be understood from FIG. 2, the relief groove 2
Since the escape grooves 4a to 24c are formed deeper than the escape grooves 22a to 22c, relatively large chips generated by the rough edges 18a to 18c can be easily guided to the outside.

On the other hand, the rotation of the rough blades 18a to 18c necessarily accompanies the rotation of the finishing blades 20a to 20c. That is, for example, the precision machining and finishing process of the finishing blade 20a immediately follows the pilot hole machining process of the rough blade 18a. Therefore, all of the preliminary hole machining formed by the rough blades 18a to 18c is accompanied by precision machining and finishing by the finishing blades 20a to 20c, so that a hole with the desired dimensions is formed in the workpiece at once. At this time, as described above, relatively small chips generated by the finishing blades 20a to 20c are discharged to the outside by the relief grooves 22a to 22c. Moreover, at the stage of transition from the finishing edge to the rough edge, as mentioned above, the relief grooves 24a to 24c are deeper than the relief grooves 22a to 22c and are cut into the center of the drill reamer. There is also no possibility that cutting friction will occur due to rotation of the drill reamer.

Furthermore, according to the structure of the drill reamer according to the present invention, the chip discharge routes of the rough blades 18a to 18c and the chip discharge routes of the finishing blades 20a to 20c are formed to have different depths. Each chip does not intrude into other cutting edges, and therefore, chips do not come into contact with other cutting edges during cutting, thereby avoiding various inconveniences such as damage to the cutting edges. Can be done.

According to the present invention, since a single drill reamer is equipped with a roughing blade and a finishing blade as described above, the primary process for drilling a pilot hole is not required, which increases equipment costs in factories, etc. can be reduced. Furthermore, drilling a pilot hole using only a rough blade may generate burrs when the drill is pulled out, but the present invention is less likely to generate burrs and is particularly suitable for workpieces that exhibit sticky characteristics. can act on Furthermore, during cutting, the tip of the drill reamer may deviate; however, according to the present invention, the rough and finishing edges are configured to contact the hole in the workpiece at at least six points. Moreover, the six-point support eliminates wobbling of the drill reamer itself, allowing stable cutting.

Moreover, since the drill reamer of the present invention has an escape groove substantially excluding the chisel point, it can easily bite into the slope of the workpiece or the material surface such as the cast surface, thereby achieving accurate hole drilling. Can be done.

According to the present invention, although the structure is simple as described above, there is an advantage that the drill device itself required for drilling the pilot hole is not required, and moreover, a precise hole of a desired size can be drilled in one operation. Therefore, for mass-produced workpieces, production efficiency can be greatly improved, and equipment costs can be extremely reduced, among other effects.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and changes in design are possible without departing from the gist of the present invention. Of course.

[Brief explanation of drawings]

FIG. 1 is a front view of a drill reamer according to the present invention;
FIG. 2 is a partial end view of the tip of the drill reamer according to the present invention. 10...Drill reamer, 12...Handle, 14...
...Blade part, 16...Flat part, 16a-16c...Cutting edge part, 18a-18c...Rough blade, 20a-20c
...Finishing blade, 22a to 22c... Relief groove, 24a
~24c...Escape groove, 26a-26c...Notch portion, 28...Tip portion, 30a-30c...Rake face.

Claims (1)

[Claims] 1. A drill reamer having a handle and a blade, the drill reamer including at least three equally spaced cutting edges each having a rough edge and a finishing edge, and forming a clearance groove between each of the cutting edges. Each of the finishing blades is formed to have a larger length in the radial direction than the rough blade, and further, the tip of the cutting blade on the axis line is formed inwardly as an inclined surface pointing toward the handle. A drill reamer characterized in that the drill reamer is formed to be inclined, and one of the rough cutting grooves in the relief grooves extends to the center of the tip of the drill reamer so as to substantially exclude the chisel point. .