JPH0639324U - Reamer - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a reamer with high accuracy and long life. A cross-sectional shape perpendicular to the axial direction of the blade portion 25 is a pentagonal or more odd-numbered polygon, or a pentagonal or more odd-numbered polygon, and one side 26 thereof has an arc shape. . The shape of the corner of the cutting edge is 30 to 5 with respect to the axial direction.
It is preferably composed of a portion having a taper shape of 0 ° and a portion having a taper shape or an R shape which is continuous with the portion and has an angle smaller than that.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a reamer having high accuracy and long life.

[0002]

[Prior art]

 Conventionally, a reamer has been used as a tool for finishing a hole. 4 and 5 show an example of a conventional reamer. The reamer 11 includes a shank portion 12 which is a portion to be gripped by a chuck of a rotary machine, a neck portion 13 which is an intermediate portion, and a blade portion 14 which is a portion to be processed. A plurality of cutting edges 15 are formed. In this example, the cutting edge 15 is a twisted edge slightly inclined with respect to the axial direction, but it may be a straight blade along the axial direction. The cutting edge 15 is composed of a plurality of pieces projecting in the circumferential direction in a sectional shape perpendicular to the axial direction thereof, and has a rake face 16, a land 17, and a groove 18. Further, a chamfered portion 19 1 cut at a predetermined angle θ with respect to the axial direction is provided at a corner portion of the tip of the blade portion 14. The chamfered portion 19 has a function of guiding the blade portion 14 into the hole and a function of preventing the corner portion of the blade portion 14 from being chipped.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned conventional reamer, the cutting edge 15 projects in the circumferential direction, and the rake face 16 thereof has a positive rake angle of about 0 ° or about 5-10 °, so that the margin of enlargement of the hole by cutting becomes large. However, there was a problem that it was difficult to control the dimensions and maintain the accuracy of the finished surface roughness. Further, there is a problem that the cutting edge 15 is easily worn and has a short life.

Therefore, an object of the present invention is to provide a reamer having a small hole expansion margin, easy size control, high-precision machining, and an excellent life.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, one of the reamers of the present invention is characterized in that the cross-sectional shape of the blade portion perpendicular to the axial direction is an odd polygon having a pentagon or more.

Another aspect of the reamer of the present invention is that the cross-sectional shape of the blade portion perpendicular to the axial direction is an odd polygon having a pentagon or more, and one side thereof is an arc shape. Characterize

In a preferred aspect of the present invention, a corner portion of the cutting edge has a tapered shape of 30 to 50 ° with respect to the axial direction, and a tapered shape with a smaller angle than that continuous with the portion or R. It is composed of a part forming a shape.

[0008]

[Action]

 In the reamer of the present invention, the cross-sectional shape perpendicular to the axial direction of the blade portion is an odd number of polygons of pentagon or more, so that the corner portions perform cutting and rubbing actions, and finish processing of holes is performed. It In this case, since the corners have an obtuse angle, the cutting action is not so strong, the enlargement margin of the hole is small, the dimensions are easily controlled, and more accurate machining is possible.

Further, since the cross-sectional shape is an odd polygon, the opposing portions do not come into contact with the inner peripheral surface of the hole when cutting is performed by one corner. Therefore, the balance at the time of cutting becomes good, and even if it wears, the runout of the blade portion at the time of cutting can be reduced. If the cross-sectional shape is an even-numbered polygon, the corners are located on the opposite lines, and when worn, the balance is lost and the runout becomes large, making machining difficult.

Further, since the cross-sectional shape is an odd polygon having a pentagonal shape or more, the cross-sectional area can be increased and the rigidity is increased, so that there is an advantage that it is difficult to bend or bend.

On the other hand, according to another aspect of the reamer of the present invention, the arc-shaped portion formed on one side of the polygon is in contact with the inner wall of the hole for finishing to prevent the tool from rotating. Make a business use. If this arcuate portion is provided on two or more sides of the polygon, the number of corners will be small and the cutting ability will be reduced, making it impossible to function as a reamer.

In a preferred embodiment of the present invention, the shape of the corner portion of the cutting edge is a portion having a taper shape of 30 to 50 ° with respect to the axial direction, and a taper shape or an R shape having a smaller angle continuous to the portion. If it is configured with the part that forms the, it becomes easier to guide the blade portion of the reamer into the hole, and the effect of reducing the expansion margin of the hole can be obtained.

[0013]

【Example】

 1 to 3 show an embodiment of a reamer according to the present invention. As shown in FIG. 1, the reamer 21 includes a shank portion 22, a reference surface 23, a neck portion 24, and a blade portion 25. Here, since the reference surface 23 cannot measure its diameter because the blade portion 25 has an odd number of polygons as described later, it is necessary to know the diameter of the blade portion 25 (the diameter of the circumscribed circle of the polygon). It provides a reference surface on which a measuring device such as a micrometer can be applied to measure the diameter.

As shown in FIG. 2, the shape of the cross section of the blade 25 perpendicular to the axial direction is an odd polygon of a pentagon or more, a pentagon in this embodiment, and one side 26 of the polygon. Has an arc shape. The pentagonal corner portion 27 serves as a portion for cutting and rubbing, and the arc-shaped side 26 serves as a portion for abutting against the inner wall of the hole to prevent the blade portion from wobbling.

As shown in FIG. 3, the tip corner portion of the blade portion 25 has a tapered portion 25 a at an angle θ ₁ of 30 to 50 ° with respect to the axial direction and an angle θ ₂ smaller than that. It is composed of a tapered portion or an R-shaped portion 25b. The length of 25a is preferably about 10 to 30% of the diameter of the reamer, and the length of 25b is about 10 to 20% of the diameter of the reamer.

The material of the reamer of the present invention is, for example, long fine particle cemented carbide, high speed steel (high speed steel), high speed steel powder, or those having a hard film such as TiN or TiCN coated on the surface thereof, and further, A CBN (cubic boron nitride) sintered body, a diamond sintered body, or the like is used.

In the above embodiment, the shape of the cross section of the blade 25 perpendicular to the axial direction is a pentagon as a whole, and one side 26 of the pentagon is a circular arc. The reamer of the invention may be one in which the shape of the cross section is an odd polygon other than a simple pentagon without the arcuate portion.

Test Example Using the reamer of the present invention shown in FIGS. 1 to 3 and the conventional reamer shown in FIGS. 4 and 5, finishing of a hole having a diameter of 2 mm and a depth of 10 mm made in a steel material (SKD11) is finished. It was processed. As a result, the reamer of the present invention could be used even after processing 500 or more holes, but the conventional reamer could not be used due to abrasion after processing about 50 holes. It was

[0019]

[Effect of device]

 As described above, according to the reamer of the present invention, the cross-sectional shape of the blade portion is an odd number polygon of pentagon or more, or one side of which is an arc shape, so that the expansion margin of the hole is reduced. , Dimension control becomes easy and high precision machining is possible. Further, since the rigidity is high, it is hard to be bent or bent and is hard to be worn, so that the life can be extended.

[Submission date] December 11, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

As the material of the reamer of the present invention, for example, ultrafine particle cemented carbide, high speed steel (high speed steel), high speed steel powder, or those whose surface is coated with a hard film such as TiN or TiCN, and further, A CBN (cubic boron nitride) sintered body, a diamond sintered body, or the like is used.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a reamer according to the present invention.

FIG. 2 is a sectional view perpendicular to an axial direction of a blade portion of the reamer.

FIG. 3 is an enlarged cross-sectional view of a tip corner portion of the blade portion of the reamer.

FIG. 4 is a side view showing an example of a conventional reamer.

FIG. 5 is a half cross-sectional view perpendicular to the axial direction of the blade portion of the reamer.

[Explanation of symbols]

 21 Reamer 25 Blade 26 One side 27 Corner

Claims (3)

[Scope of utility model registration request] 1. A reamer characterized in that a cross-sectional shape perpendicular to the axial direction of the blade portion is an odd polygon having a pentagon or more. 2. A reamer characterized in that a cross-sectional shape of the blade portion perpendicular to the axial direction is an odd polygon having a pentagon or more and one side thereof is an arc shape. 3. The shape of the corner of the cutting edge is 3 with respect to the axial direction.
The reamer according to claim 1 or 2, wherein the reamer comprises a taper portion of 0 to 50 ° and a taper portion or an R shape portion which is continuous with the taper portion and has an angle of less than that.