JP4695365B2 - Part-Time Job - Google Patents

Description

  The present invention relates to a cutting tool suitable for cutting (boring) an inner peripheral surface of a workpiece such as metal.

  Conventionally, a boring tool is used in the case of so-called boring, in which a hole inner peripheral surface of a workpiece is cut by a lathe or the like.

  Since this boring tool is used to process the inner peripheral surface of the hole, the boring tool is formed to be thin overall, including the shank portion, compared to a tool that processes the outer peripheral surface.

  For this reason, it is rigidly lower than other cutting tools for processing the outer peripheral surface and the like, and therefore, a large cutting amount cannot be obtained compared to a normal cutting tool. It is easily generated.

  Therefore, in the case of this type of boring tool, how to increase the rigidity of the entire tool including the shank part increases the cutting efficiency and suppresses chatter and improves the finishing accuracy of the workpiece. It is closely related.

For this reason, attempts have been made to increase the rigidity of the boring tool (see Patent Document 1).
JP 11-285906 A

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a bite that is slender overall and has improved overall rigidity.

  The object of the present invention can be solved by a byte having the following configuration.

The cutting tool according to the present invention is a cutting tool suitable for boring a workpiece,
While having a rake face with a tip holding part at the tip part for mounting and fixing the chip,
A reinforcing wall that protrudes in the bite thickness direction and has a predetermined wall thickness is provided on the rake face on the back side of the chip holding portion and extends over the entire length direction of the rake face.

According to the cutting tool according to the present invention having the above-described configuration, since the reinforcing wall protrudes in the cutting tool thickness direction from the rake face, the rigidity of the entire cutting tool is increased as much as possible. The state of vibration transmitted from the cutting part can be changed by setting various protrusion dimensions or protrusion shapes of the reinforcing wall, and the natural frequency of the cutting tool itself can be changed. It is possible to avoid the “billing” that is about to occur as much as possible.
And since this reinforcement wall has the form of a wall, it becomes possible to change the natural frequency of a bite easily.

  In the cutting tool, the tip of the reinforcing wall is configured such that the height of the wall gradually decreases toward the tip, thereby providing substantially uniform bending rigidity over the entire length of the cutting tool tip. Byte can be realized.

  Furthermore, in the cutting tool, when the upper surface of the tip of the reinforcing wall is formed of a curved surface having a negative curvature (a concave curved surface), the natural frequency is finely adjusted by changing the rigidity and elasticity. The above configuration is preferable.

  Further, in the bite, when the corner portion on the opposite side across the tip holding portion and the reinforcing wall is cut from the side end of the reinforcing wall to the outer portion, when drilling, It is possible to realize a tool whose tip does not contact the hole bottom or the like.

  Hereinafter, the cutting tool according to the present invention (in this embodiment, “boring tool”) will be described in detail with reference to the drawings. However, the present invention is not limited to boring bytes.

  FIG. 1 is an overall perspective view showing an overall schematic configuration of a boring tool according to an embodiment of the present invention.

In FIG. 1, A is a boring tool, 1 is a “rake face” for scooping cutting chips during cutting, 2 is a tip holding portion formed at the tip of the rake face, and 3 is held by the tip holding portion 2. The chip 4 is a reinforcing wall provided so as to protrude upward (in the bite thickness direction) on the back side of the chip holding portion, and 5 is a shank portion formed on the base end (left side in FIG. 1) of the rake face 1. is there.
In the case of this embodiment, the rake face 1 is formed as a face substantially parallel to the longitudinal direction of the shank portion 5 (precisely, a face slightly inclined upward at the tip). The tip holding portion 2 is recessed at the left end of the rake face 1 so as to have an inclination angle that is upward at an angle of about 5 ° on the tip side with respect to the longitudinal direction of the shank portion 5. Yes. However, this angle is not limited to approximately 5 °, and may be in the range of 4 ° to 6 ° or in the range of 3 ° to 8 ° depending on cutting conditions (conditions such as the material of the workpiece). . The chip 3 held on the chip holding part 2 has a shape having a rhombus shape and a uniform thickness in a plan view, and has cutting edges formed on four sides of the upper surface. When the cutting is stopped, it is rotated 90 ° and set so that a new side becomes a cutting blade for cutting, whereby each side of the four sides can be used sequentially as a cutting blade.
As shown in FIG. 3, the tip 3 is inclined at an angle of approximately 5 ° on the tip side with respect to the longitudinal direction of the shank portion 5 due to the inclination angle of the tip holding portion 2. It is arranged with. This inclination angle is the front rake angle j of the cutting tool A (chip 3).
In addition, the chip 3 is arranged with an inclination angle with a higher right end (left end toward the tip of the cutting tool A) in the front view shown in FIG. 5, and this inclination angle is another rake angle (lateral rake). Corner). This lateral rake angle k is also set to approximately 5 ° in this embodiment. However, the lateral rake angle k may be changed as appropriate depending on the cutting conditions, like the front rake angle j.
As shown in FIG. 1 or 2, the chip 3 has a back surface 3 b and a right side surface 3 s that are in surface contact (contact) with the back end surface 2 b and the right end surface 2 s of the chip holding unit 2. In addition, as a result of being fixed to the chip holding unit 2 from above by the bolts 6, the chip holding unit 2 is firmly fixed and held integrally with the chip holding unit 2.
Further, as shown in FIG. 3, the tip surface 3e of the chip 3 held by the chip holding unit 2 as described above protrudes forward from the tip surface 2e of the chip holding unit 2, and As shown in FIG. 5, the left end surface 3 w of the chip 3 protrudes to the left (right in FIG. 5, which is a front view) from the left end surface 2 w of the chip holding unit 2.
And the front-end | tip part 4f of the reinforcement wall 4 is located in the right part toward the front-end | tip of the said chip | tip holding | maintenance part 2 of the said rake face 1, and this reinforcement wall 4 goes to this base end side from this front-end | tip. As described above, the shank 5 extends in the longitudinal direction and extends over substantially the entire length of the rake face 1. Further, the reinforcing wall 4 is formed so as to protrude upward (in the thickness direction of the cutting tool) from the chip holding part 2 in the height direction, and the wall height increases toward the tip end at the tip part 4f. Are configured so as to be sequentially lowered. More specifically, at the front end portion 4f, the upper surface 4u of the reinforcing wall 4 has a round shape in a side view due to a curved surface having a negative curvature. Then, the height gradually increases linearly from the distal end portion 4f further toward the rear (base end direction), and is highest at the proximal end portion of the rake face 1. In this embodiment, the height of the highest portion of the reinforcing wall 4 is set to approximately 50% of the total height of the shank 5. Further, with respect to the width of the reinforcing wall 4, the average value of the width of the upper surface 4 u is set to about 5 to 10% of the total height of the shank 5. However, it is not limited to these ratios. Further, the above-described change state of the upper surface 4u may be changed in response to vibration to prevent chattering. In particular, the change state of the upper surface 4u can be easily changed using a grinder or the like.
Further, as shown in FIG. 2, the upper surface 4u of the reinforcing wall 4 is wide at the distal end side and gradually narrowed at the proximal end as shown in FIG. And this reinforcement wall 4 is comprised so that a width | variety may become wide as it goes below from the upper surface 4u over the full length. Further, the left side surface 4g of the reinforcing wall 4 extends toward the tip of the base end portion 4b so as to draw a large curvature (loose curvature) up to the side end of the rake face 1. Similarly, the side surface 4p on the right side of the base end portion 4B of the reinforcing wall 4 extends so as to draw a smaller curvature from the left side to the right end of the tip end portion of the cutting tool A.

  Further, as shown in FIG. 1 or FIG. 2 or the like, the corner on the opposite side of the tip holding portion across the reinforcing wall 4 at the tip of the cutting tool A, that is, the right corner 8 at the tip of the cutting tool A is The reinforcing wall 4 is cut substantially linearly from the side end portion to the outer portion.

  Further, in the case of this embodiment, the shank 5 is constituted by a straight rod having a non-circular cross section. Specifically, in a cross-sectional view, the circular upper end, lower end, left end, and right end are formed in a non-circular shape that is cut into a flat shape so that the cut ends are discontinuous.

  Further, a stepped portion 7 that is thicker on the shank 5 side (base end side) is formed at a boundary portion between the shank 5 and the reinforcing wall 4 that spreads at both ends.

Therefore, the boring tool A according to this embodiment configured as described above has the following operational effects. That means
As described above, the reinforcing wall 4 protruding upward (in the thickness direction of the cutting tool) is extended along the longitudinal direction of the cutting tool at the tip of the cutting tool A having low rigidity. This contributes to increasing the rigidity of the part. Moreover, as described above, the distal end portion of the reinforcing wall 4 is configured by a curved surface having a negative curvature, and the base end of the reinforcing wall 4 is linearly inclined so as to be higher at the base end, and is reinforced. Since the wall 4 is wide at the front end side in the width direction, the wall 4 has a shape substantially corresponding to the bending moment acting on the cutting tool A by the cutting reaction force. For this reason, it becomes a form which is hard to produce "chatter" resulting from cutting.
For this reason, compared with the conventional form boring tool, large cutting work is possible, and "chatter" generated by cutting is also reduced.

  Further, as described above, since the right corner of the tip of the cutting tool A is notched, it is possible to perform cutting effectively without contacting the hole bottom or the like even in drilling (boring). .

  Further, as described above, the distal end portion 4f of the reinforcing wall 4 is configured to be wide and have little upward protrusion, so that it does not come into contact with the peripheral wall in drilling with high rigidity.

  A tool suitable for boring according to the present invention can be used as a cutting tool for a machine tool such as a lathe.

It is the whole perspective view which showed the structure of the whole outline of the boring tool concerning one Example of invention. It is a top view (II-II arrow line view of FIG. 1) of the boring tool shown in FIG. FIG. 3 is a left side view of the boring tool shown in FIG. 1 (viewed along arrows III-III in FIG. 2). FIG. 4 is a right side view of the boring tool shown in FIG. It is a front view (VV arrow view of FIG. 2) of the boring tool shown in FIG.

Explanation of symbols

A ... Boring bytes (bytes)
1 ... Rake face
2 ... Chip holding part
3 ... chip
4 ... Reinforcement wall
5 ... Shank

Claims (4)

A tool suitable for boring a workpiece,
While having a rake face with a tip holding part at the tip part for mounting and fixing the chip,
On the rake face on the back side of the chip holding part, a reinforcing wall protruding in the bite thickness direction and having a predetermined wall thickness is extended in the longitudinal direction .
The reinforcing wall extends in the longitudinal direction of the cutting tool from the side of the tip of the chip holding part to the rake face on the back side of the chip holding part,
The tip of the reinforcing wall is configured such that the wall height decreases sequentially as it goes toward the tip,
The upper surface of the distal end portion of the reinforcing wall is formed in a round shape by a curved surface that is concave from the distal end of the reinforcing wall toward the proximal end,
The reinforcing wall is configured such that the width becomes wider as it goes downward from the upper surface of the distal end portion of the reinforcing wall, and the upper surface is wide at the distal end side and gradually narrowed at the proximal end. Byte to do. One side surface of the cutting tool toward the tip of the base end of the reinforcing wall extends to draw a small curvature curve to the side edge of the rake face,
The other side surface of the cutting tool toward the tip of the base end portion of the reinforcing wall is drawn with a larger curvature curve than the one side surface to the side end located on the other side surface side of the step portion of the cutting tool. 2. The byte according to claim 1, wherein the byte is widened. 3. The height of the reinforcing wall is increased so as to increase linearly further toward the rear, and is highest at the base end of the rake face. Bytes. The lateral rake angle of the chip is preferably formed at about 5 degrees,
Corner portions of the opposite side at a reinforcing wall and the chip holding portion, either from the side end of the tip of the reinforcing wall over the outer portion, of the claims 1 to 3, characterized in that the cut away 1 Bytes described in section .

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