JPH0429932Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a drill reamer, and more specifically,
It is possible to perform rough cutting to form a pilot hole and finish cutting to precisely machine the pilot hole drilled by the rough cutting to predetermined dimensions in a single process. This invention relates to a drill reamer that has a simple structure and can be manufactured at low cost.

[Prior Art] In general, a conventional drill reamer is known in which a plurality of straight grooves are provided in parallel to an axis and drill cutting edges and reaming cutting edges are alternately arranged.

Further, as a method for forming a hole portion with high dimensional accuracy, it is generally known that two different processing steps are performed. In other words, high precision is achieved by performing two separate processes: rough cutting to form a pilot hole with a smaller diameter than the predetermined size using a drill, and finish cutting to finish the hole with the desired dimensional accuracy by inserting a reamer into the pilot hole. It forms a hole.

[Problems to be solved by the invention] As mentioned above, in a drill reamer in which the cutting blades for the drill and the cutting blades for the reamer are arranged alternately, if the machining allowance for the reamer is too large, the cutting resistance increases, and if it is too small, the cutting force will be left behind. This caused the problem of poor surface accuracy.

Furthermore, with conventional tools that perform rough cutting and finishing cutting separately, the hole machining operation becomes complicated and requires a considerable amount of time. Moreover, providing dedicated equipment for drilling and reaming each would be a considerable economic burden, and if each of the equipment were to be installed separately, the space for this would significantly expand and become narrow. It is difficult to employ this method in a workplace, and on the other hand, even if a temporary arrangement can be made, the inconvenience of not being able to make the most effective use of the space becomes apparent.

The present invention has been made in order to overcome the above-mentioned disadvantages, and has the main body part constituting the drill reamer alternately formed with a rough cutting edge for drilling a preliminary hole and a finishing cutting edge for finishing cutting. By selecting the radial length of the rough blade and the finishing blade within a predetermined range, it is possible to form through holes and blind holes with high dimensional accuracy, and it also has high rigidity and therefore durability. The purpose is to provide excellent drill reamers.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention is a drill reamer having a handle part and a blade part, and the blade part has a cutting blade part consisting of a rough blade and a finishing blade. At least two of the finishing blades are provided, and the diameter of the finishing blade is set larger within the range of 5/1000 mm to 4/100 mm than the diameter of the roughing blade, and a flat or arcuate shape is provided between the finishing blade and the roughing blade. A relief groove is formed, and the cutting tip at the radial end of the rough blade is located closer to the workpiece than the cutting tip of the finishing blade.

[Function] According to the above configuration, the length in the diametrical direction of the finishing blade is specified, and an relief groove is formed between the finishing blade and the roughing blade, and furthermore, the cutting tip of the roughing blade is aligned with the cutting edge of the finishing blade. It is closer to the workpiece side than the cutting tip. Therefore, through holes, blind holes, etc. can be formed with high dimensional accuracy.

[Example] Next, a preferred example of the drill reamer according to the present invention will be described in detail with reference to the accompanying drawings.

1 and 2, reference numeral 10 designates a drill reamer according to the present invention. This blade, the drill reamer 10 basically has a handle part 12 and a blade part 1.
4. The handle portion 12 forms a so-called straight shank, and has a flat portion 16 extending from its end toward the center for holding by a rotational drive source (not shown).

The blade part 14 has two cutting blade parts 18a and 18b at symmetrical positions with respect to its center, and the first cutting blade part 18a and the second cutting blade part 18b are rough holes for machining the prepared hole, respectively. It includes blades 20a, 20b and finishing blades 22a, 22b for finishing cutting that are connected to the blades 20a, 20b. A planar clearance groove 24 extending in the axial direction of the blade portion 14 is provided between the rough blade 20a and the finishing blade 22a.
The finishing blades 22a are connected linearly by a groove 24a, and chips generated by the finishing blade 22a are led out to the outside from the relief groove 24a. On the other hand, a planar clearance groove 24b is also formed between the roughing blade 20b and the finishing blade 22b for guiding out chips generated by the finishing blade 22b.

In this case, as shown in FIG.
The diametrical length (φD ₁ ) of 20b is the finishing blade 22
5/10 of the diametrical length (φD ₂ ) of a and 22b
Select 00mm to 4/100mm shorter. On the other hand, between the first cutting edge portion 18a and the second cutting edge portion 18b, that is, the finishing edge 22a, the roughing edge 20b, and the finishing edge 2
2b and the rough blade 20a, there are relief grooves 26a, 26b that are notched radially inwardly at an angle of approximately 90° and extend linearly in the axial direction of the blade portion 14. form. The relief groove 2
6a and 26b lead out relatively large chips generated by the rough edges 20a and 20b to the outside.

Furthermore, the first cutting edge 18a has a first flank 28a that is largely inclined toward the chisel point at the tip of the blade 14, and a second flank that is inclined with respect to the first flank 28a. 30a. Therefore, the rough blade 20a is connected to a tip cutting blade 32a provided at the ridgeline portion of the first and second flank surfaces 28a and 30a. On the other hand, in the second cutting edge portion 18b, similarly, a first flank 28b and a second flank 30b are formed which are largely inclined toward the chisel point, and the tip cutting edge 32b extends from the chisel point. It is provided facing the rough blade 20b. In this case, the cutting tips of the rough blades 20a, 20b are closer to the tip of the blade portion 14 than the cutting tips of the finishing blades 22a, 22b.

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

First, the flat part 16 of the handle 12 is connected to a rotational drive source (not shown) via a chuck or the like, and the drill reamer 10 is rotated under the action of the rotational drive source. Next, when the drill reamer 10 and the work W are moved relatively close to each other, the tip of the blade portion 14 starts cutting the work W. That is, after the tip cutting blades 32a, 32b formed at the tip of the blade portion 14 start drilling a hole in the workpiece W, the rough cutting blades 20a, 20b connected to the tip cutting blades 32a, 32b start drilling. The radially extending end substantially begins rough cutting of the workpiece W to form a pilot hole. In this case, the chips generated by the rough blades 20a and 20b are removed from the relief groove 2.
6a, 26b toward the handle 12, and then led out to the outside.

As mentioned above, the diameter of the rough blades 20a, 20b is selected to be smaller than that of the finishing blades 22a, 22b, and the cutting tips of the rough blades 20a, 20b are smaller than the cutting tips of the finishing blades 22a, 22b. Close to the point side. Therefore, when the drill reamer 10 is further rotated, each rough edge 2
The prepared holes formed in the workpiece W by 0a and 20b are subjected to precision finishing using partial finishing blades 22a and 22b. As a result, after the workpiece W is drilled with the drill reamer, finishing is immediately performed, making it possible to form a through hole or a blind hole in an extremely short time.

In this case, the present inventor conducted an experiment using aluminum alloy, iron, steel, etc. as the workpiece W, and found that the diameter φD ₁ of the rough blades 20a, 20b was 5/1000 mm or more than the diameter φD ₂ of the finishing blades 22a, 22b. 4/100
It has been confirmed that if the diameter is selected to be smaller by mm, precise and good finishing cutting can be performed on the desired hole.

In other words, the inner wall surface of the pilot hole formed by the rough blades 20a and 20b has relatively poor precision, resulting in uneven stepped portions. Therefore, the rough blades 20a, 20b
If the difference between the diameter φD ₁ of the finishing blades 22a and 22b and the diameter φD ₂ of the finishing blades 22a and 22b is smaller than 5/1000 mm, the uneven stepped portion of the prepared hole cannot be completely removed by the finishing blades 22a and 22b, A step portion remains on the inner wall surface of the hole after finishing, and the surface accuracy of the inner wall surface of the hole becomes extremely low. On the other hand, if the difference between the diameters φD ₁ and φD ₂ is larger than 4/100 mm, the step on the inner wall surface of the prepared hole is completely removed by the finishing blades 22a and 22b, but in this case, the cutting amount of the finishing blades 22a and 22 is becomes considerably large, and the respective finishing blades 22a,
22b becomes susceptible to wear and tear. Furthermore, built-up cutting edges are formed on the finishing blades 22a and 22b, making it impossible to achieve highly accurate finishing cutting.

Therefore, as in the present invention, the rough blades 20a, 20b
By selecting the diameter φD ₁ smaller than the diameter φD ₂ of the finishing blades 22a, 22b by 5/1000 mm to 4/100 mm, the finishing blades 22a, 22b can remove all the steps on the inner wall surface of the prepared hole and improve the surface accuracy. It becomes possible to form a high desired hole.

Furthermore, in the drill reamer 10 according to the present invention, the rough blades 20a, 20b and the finishing blades 22a, 22b.
Relief grooves 24a and 24b are formed in a planar shape extending in the axial direction of the blade portion 14. Therefore, the manufacturing operation of the drill reamer 10 is extremely simplified, and there is an advantage that the drill reamer 10 can be manufactured economically.

Next, other embodiments of the drill reamer according to the present invention are shown in FIGS. 4 and 5. Note that the same reference numerals are given the same reference numerals with the suffix "a" attached to the same components as those in the first embodiment, and detailed explanation thereof will be omitted.

In this case, in the second embodiment, similarly to the first embodiment, the blade portion 14a is provided with a first cutting edge portion 34a and a second cutting edge portion 34b, and the first and second cutting edges are The blade portions 34a and 34b are formed with a rough blade 36a, a finishing blade 38a, a rough blade 36b, and a finishing blade 38b, respectively. The length of the roughing blades 36a, 36b in the diametrical direction is 5/5/2.
Select a size smaller than 1000mm to 4/100mm. Then, the rough blades 36a, 36b and the finishing blades 38a, 38b.
Relief grooves 40a, 40b having an arcuate cross section are formed between the first cutting edge 34a and the second cutting edge 34b, and an relief groove 42a is formed by cutting a large portion inward of the blade 14a. , 42b. The cutting blade portions 34a and 34b configured in this manner each extend spirally in the direction of the handle portion 12a.

In such a configuration, the drill reamer 1
It will be easily understood that when the workpiece W is machined using the drill reamer 0a, it is carried out in the same manner as in the drill reamer 10 of the first embodiment described above. Also, in this case,
Since the clearance grooves 40a, 40b between the rough blades 36a, 36b and the finishing blades 38a, 38b are formed with an arcuate cross section, the manufacturing work of the drill reamer 10a, which is performed using a circular grindstone, etc., is extremely simplified, and The drill reamer 10a itself can be manufactured economically.

[Effects of the invention] As described above, according to the invention, a single drill reamer is provided with a roughing blade and a finishing blade, and the diametrical length of the roughing blade and the diametrical length of the finishing blade are selected. However, the workpiece is configured to first perform a pilot hole machining with the rough blade, and then immediately perform precision finishing of the pilot hole with the finishing blade. For this reason, high-precision hole machining, which was conventionally done in two processes, can be performed in a single process, and the hole machining work can be easily and quickly made into through holes or blind holes. etc. can be formed. Furthermore, compared to the conventional method where drilling equipment and reaming equipment are installed side by side, equipment costs are significantly reduced, and the area occupied by the equipment in the factory is reduced as much as possible. can get. Moreover, the structure of the drill reamer can be extremely simplified and the drill reamer can be manufactured at a much lower cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a drill reamer according to the present invention;
FIG. 2 is a partial plan side view of the drill reamer according to the present invention, FIG. 3 is a front view of the tip of the drill reamer, FIG. 4 is a perspective view of another embodiment of the drill reamer according to the present invention, and FIG. 5 is a front view of the tip of the drill reamer shown in FIG. 4. FIG. 10...Drill reamer, 12...Handle, 14...
...Blade part, 18a, 18b...Cutting blade part, 20a, 2
0b... Rough blade, 22a, 22b... Finishing blade, 24
a, 24b, 26a, 26b... relief groove, 28
a, 28b, 30a, 30b... Relief surface, 34
a, 34b... Cutting edge portion, 36a, 36b... Rough blade, 38a, 38b... Finishing blade, 40a, 40
b, 42a, 42b...Escape groove.

Claims (1)

[Scope of utility model registration request] A drill reamer having a handle and a blade,
The blade part is provided with at least two cutting blade parts consisting of a rough blade and a finishing blade, and the diameter of the finishing blade is set to be larger than the diameter of the rough blade within a range of 5/1000 mm to 4/100 mm, A planar or arcuate clearance groove is formed between the finishing blade and the roughing blade, and the cutting tip at the radial end of the roughing blade is positioned closer to the workpiece side than the cutting tip of the finishing blade. A drill reamer characterized by: