JP2018089737A - drill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To directly supply cooling liquid to a part where a blade tip comes into contact with a work and increase the supply pressure to enhance cooling effect for the blade tip and cut chips into tiny pieces.SOLUTION: A drill 1 is provided with a cooling liquid jetting port 7A at the tip part thereof and configured so that cooling liquid jetted from the cooling liquid jetting port 7A is jetted toward a blade tip 21. The cooling liquid jetting port 7A is provided in the vicinity of an outer side corner part of the blade tip 21 and jets the cooling liquid with high pressure to supply the cooling liquid to a part where the blade tip 21 directly comes into contact with a work.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drill for processing automobiles and other machine parts, and more particularly to a drill provided with a coolant jet.

  Conventionally, when drilling holes in light alloys such as aluminum and steel materials, drills are prevented from being damaged due to heat generated by rubbing between the cutting edge surface of the drill and the work piece, and the life of the drill is increased. The coolant is supplied to the tip side. Then, the cooling liquid ejected from such a cooling liquid ejection hole is pressurized and supplied to the cooling liquid ejection hole through a cooling liquid supply passage provided penetrating through the main shaft of the drill.

  In this case, since the coolant is only ejected from the coolant ejection hole to the front side of the main shaft, the coolant is ejected onto the workpiece scraped by the cutting blade. Is not supplied to the part that is in direct contact with the workpiece. Therefore, there is a problem that the cutting blade becomes hot due to friction with the workpiece, deformation / wearing occurs, and the life is shortened.

  Therefore, in order to solve such a problem, by supplying the coolant directly to the portion where the cutting blade and the workpiece are in contact with each other, excellent cooling of the cutting blade and the workpiece is performed, and deformation and wear are prevented. In addition, by the synergistic effect of supplying the coolant to the above part and increasing the supply pressure, fine cutting of chips is realized, and chip discharge and subsequent processing are facilitated. Has been attempted (see, for example, Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 2015-24479 Japanese Patent Laid-Open No. 2006-144865

  By the way, in the case of a machine part such as an automobile such as an engine cylinder block or cylinder head, it is more strongly required than a general processed product that chips remain as much as possible in a machining hole of a machined part. Conventional chips have a size of about 15 mm or more, and wound chips have been generated. Therefore, chips may enter the cylinder block, the cylinder head, etc., and remain.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a drill that cuts cut chips more finely and surely so that chips do not remain as much as possible in the machining holes of the parts after cutting. And

  In order to solve the above problems, a drill according to the present invention is a drill for machining a machine part, a cutting portion having a cutting edge at a tip portion, a groove portion for discharging chips cut on a side surface, A shaft portion that continues to the base end portion of the cutting portion, and the shaft portion includes a first coolant supply path through which the coolant passes, and the cutting portion includes a second cooling portion therein. It has a liquid supply path and a third coolant supply path connected to the second coolant supply path, and is connected to the third coolant supply path at the tip, and jets the coolant toward the cutting edge. The second coolant supply path has a diameter equal to or smaller than the diameter of the first coolant supply path, and the diameter of the third coolant supply path is It is characterized by being formed smaller than the diameter of the second coolant supply path.

  In this way, the cooling liquid is ejected from the first cooling liquid ejection port provided at the tip portion toward the cutting edge, so that the cooling liquid is efficiently supplied to the portion where the cutting edge and the workpiece are in direct contact with each other. The Therefore, the effect of cooling them is excellent, wear can be suppressed, and the life can be extended. As a result, the processing speed can be increased, and excellent and efficient hole processing can be realized.

  Further, the diameter of the second coolant supply path is equal to or smaller than the diameter of the first coolant supply path, and the diameter of the third coolant supply path is smaller than the diameter of the second coolant supply path. Therefore, the coolant can be ejected from the first coolant ejecting port at a higher pressure than in the past. At the same time, the pressure of the coolant supply path inside the drill is increased, so that the drill is prevented from shaking and high-precision machining is realized. This is the same principle that the higher the pressure of water flowing in the hose, the more the hose swaying is suppressed.

  As a result, the straightness of the drill is improved, and a high-pressure coolant is ejected to a portion where the cutting edge and the workpiece are in direct contact with each other, so that the shaved chips are cut into short dimensions. When the chips are cut into short dimensions in this way, the chips are easily discharged to the outside, and the chips are not left in the processed holes of the automobile part after the cutting process.

  The drill includes a pair of the first coolant jet, the blade tip, and the groove, and the first coolant jet is provided in the vicinity of the outer corner portion of the one blade tip. The other first coolant jet is preferably provided in the vicinity of the outer corner of the other blade edge.

  According to this configuration, the high-pressure coolant is ejected from the pair of coolant outlets to the pair of blade edges. Since these coolant outlets are provided in the vicinity of the outer corners of the cutting edges, the high-pressure cooling liquid can be jetted inward substantially horizontally from the nearest to the respective cutting edges. The cooling liquid can be efficiently ejected to the portion in direct contact with the material. Further, since the coolant is ejected inward, that is, toward the groove portion, the cut chips are efficiently discharged. As a result, processing can be performed more efficiently than before.

  Further, in the drill, the cutting portion further includes a fourth coolant supply path that is connected to the second coolant supply path, a second coolant jet port that is connected to the fourth coolant supply path, There are two second coolant jets. According to this configuration, the coolant outlets have four configurations, and the coolant is ejected from the plurality of coolant outlets toward the cutting edge.

  Here, for example, a configuration in which the second coolant ejection port is disposed at the distal end portion of the cutting portion, a configuration in which the second coolant ejection port is disposed at a position shifted from the first coolant ejection port to the proximal end side, and the like are conceivable. Moreover, it is good also as a structure provided with six coolant outlets combining these structures. Further, in the case of a configuration in which the second coolant jet is arranged at a position shifted from the first coolant jet to the base end side, a blade edge is further placed at a position substantially horizontal to the second coolant jet. It is good also as a structure provided.

  Preferably, in the drill, the coolant jetted from the first coolant jet port has a high pressure of 7 MPa or more and 30 MPa or less.

  In the present invention, since the coolant jetted from the coolant jet is supplied to the blade tip at a high pressure, the cut chips are cut with a shorter dimension than before, so that the remaining chips inside the automobile parts are not present. It is suppressed. Further, the internal pressure of the coolant supply path inside the drill is improved, and the straightness of the drill is improved. As a result, the processing speed can be increased and efficient processing becomes possible.

It is a front view showing a drill concerning one embodiment of the present invention. It is a bottom view showing a drill concerning one embodiment of the present invention. It is a figure which shows the chip using the drill which concerns on one Embodiment of this invention. It is a figure which shows the chip using the conventional drill. It is a front view which shows the drill of a modification. It is a bottom view which shows the drill of a modification. It is sectional drawing in the AA of FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments. In particular, in the present embodiment, two coolant outlets are provided in the cutting part at the tip, but the present invention is not limited to this. For example, the coolant outlets at the tip may have four configurations, and the coolant may be provided at the intermediate portion.

  FIG. 1 is a front view of a drill according to the present embodiment, and FIG. 2 is a bottom view thereof. As shown in FIGS. 1 and 2, the drill 1 of this embodiment is used for machining machine parts such as an aluminum cylinder head, for example, and two cutting edges 21 and 21 having a certain width are symmetrical. A plurality of flank surfaces 3, 4, and 5 are formed in order after the cutting edge 21, and further to the flank surfaces 3 to 5 and to the chip discharge groove surface 6. A shaft portion 9 is connected to the base end portion of the cutting portion 2. The cutting edge 21 is formed of high-speed steel or cemented carbide.

  In addition, a cooling liquid supply path 81 through which the cooling liquid flows in the axial direction is provided in the shaft portion 9 along the axial direction. Further, inside the cutting portion 2, there are a coolant supply path 82 extending substantially in the center along the axial direction, and a coolant supply path 83 extending from here to like a branch and extending to a coolant outlet 7A described later. Is provided.

  The diameter of the coolant supply path 83 is configured to be smaller than the diameter of the coolant supply path 82, and the diameter of the coolant supply path 82 is configured to be smaller than the diameter of the coolant supply path 81. Thereby, the internal pressure of the coolant flowing through these coolant supply paths is improved, and the straightness of the drill is improved. In the present embodiment, as an example, the coolant supply path 81 has a diameter of 4 mm, the coolant supply path 82 has a diameter of 3 mm, and the coolant supply path 83 has a diameter of 0.9 mm. Hereinafter, the coolant supply paths 81 to 83 may be collectively referred to as the coolant supply path 8.

  Further, a coolant jet 7A is provided in the vicinity of the outer corner portion of each blade edge 21, and the coolant is supplied toward the blade edge 21 (particularly the outer corner portion) that greatly contributes to cutting. Thereby, the cooling liquid ejected from the cooling liquid ejection port 7A is smoothly supplied to the portion where the blade edge 21 and the workpiece are in contact with each other.

  That is, since the coolant outlet 7A is provided in the vicinity of the outer corner portion of the blade edge 21, the coolant is directed toward the blade edge 21, that is, to the contact portion between the blade edge 21 and the workpiece from the coolant outlet 7A. It is designed to be supplied directly over a short distance.

  Therefore, with the structure in which the coolant outlet 7A is provided in the vicinity of the outer corner portion of the cutting edge 21 that greatly contributes to cutting, the cutting edge 21 and the workpiece are directly connected to the coolant discharged from the coolant outlet 7A. It will be efficiently supplied to the parts that come into contact with each other, and it is excellent in these cooling effects, and it is possible to suppress the wear of the cutting edge of the drill 1 and extend its life. Further, since the coolant is supplied inward, the cut chips are smoothly introduced into the discharge groove. As a result, the processing speed can be increased, and excellent and efficient processing is possible.

  Then, using a high pressure pump (not shown) manufactured in-house, the pressure of the cooling liquid ejected from the cooling liquid outlet 7A through the cooling liquid supply path 8 is 7 to 30 MPa, that is, 7 MPa or more and 30 MPa or less. I have to. In the present embodiment, the pressure is 15 MPa. By supplying at such a high pressure, the coolant that is ejected from the coolant ejection port 7A is scraped off from the workpiece due to the synergistic effect of being directly supplied to the contact portion between the cutting edge 21 and the workpiece. The chips are immediately cut at a very short dimension by the coolant jetted at high pressure, flow into the discharge groove surface 6 together with the coolant, and are smoothly discharged out of the drill 1 from the discharge groove surface 6.

  The diameter of the coolant jet 7A is 0.9 mm as an example, and is formed sufficiently smaller than the diameters 3.0 mm and 4.0 mm of the coolant supply channels 81 and 82, so that the coolant is supplied at a high pressure. It is easy to realize. Actually, the relationship between the coolant supply pressure and the chip size when the material of SCM415 (chrome molybdenum steel) is turned with a lathe is as follows.

  When the supply pressure of the coolant is 2 MPa, the length of the chip is 50 mm or more, when it is 7 MPa, around 30 mm, when 10 MPa, it is cut to about 15 mm, and when it is 15 MPa, it becomes about 7 mm. When the pressure was 20 MPa, the size was about 5 mm, when the pressure was 25 MPa, the size was about 3 mm, and when the pressure was 30 MPa, the size was about 3 mm.

  In this way, by supplying the coolant at a high pressure, the chips are cut into extremely short dimensions, so that it becomes easy to pass through the discharge groove surface 6. Moreover, since the chip | tip after discharging | emitting from the drill 1 is cut | judged to a short dimension, it can be accommodated in the container of arbitrary shapes, The process is also easy. 3 shows the chips cut by the drill of the present embodiment, and FIG. 4 shows the chips cut by the conventional drill.

  Next, a modification of this embodiment will be described. The main difference between this drill 100 and said drill 1 is the number and arrangement of coolant jets. The drill 100 has a configuration in which four coolant outlets are provided in the cutting portion at the tip, and two coolant outlets are provided in the intermediate portion. Hereinafter, the description will focus on the differences, the description of the same parts as the drill 1 will be omitted, and the same reference numerals will be used for the same configurations.

  FIG. 5 is a front view showing the drill 100. FIG. 6 is a bottom view of the same. 7 is a cross-sectional view taken along line AA in FIG. As shown in FIGS. 5 to 7, the cutting portion 120 of the drill 100 has a coolant outlet 7 </ b> B at the inner corner portion in addition to the coolant outlet 7 </ b> A provided at the outer corner portion of the cutting edge 21 at the tip portion. And a coolant outlet 7C in the middle part. In addition, a cutting edge 121 is provided at the intermediate portion, and the cooling liquid is jetted from the cooling liquid outlet 7C toward the cutting edge 121 during cutting.

  Further, the coolant jet port 7 </ b> B is connected to the coolant supply path 84, and the coolant supply path 84 is connected to the coolant supply path 82. Further, the coolant jet port 7 </ b> C is connected to the coolant supply path 85, and the coolant supply path 85 is connected to the coolant supply path 82.

  As described above, the preferred embodiments of the present invention have been described with reference to the drawings, but various additions, modifications, or deletions can be made without departing from the spirit of the present invention. For example, the inclination angle and twist angle of each flank can be appropriately changed. Further, the number of cutting edges may be three or more, and is not limited to two.

DESCRIPTION OF SYMBOLS 1,100 Drill 2,120 Cutting part 21,121 Cutting edge 3,4,5 Flank 6 Discharge groove surface 7A, 7B, 7C Coolant jet 81, 82, 83, 84, 85 Coolant supply path 9 Shaft part

Claims (4)

A drill for machining machine parts,
A cutting part having a cutting edge at the tip part;
A groove for discharging chips cut on the side surface;
A shaft portion that continues to the base end portion of the cutting portion,
The shaft portion has a first coolant supply path through which coolant passes.
The cutting part is
Inside the second coolant supply path,
A third coolant supply path connected to the second coolant supply path,
At the tip, the first coolant liquid outlet is connected to the third coolant supply path and ejects the coolant toward the cutting edge.
A diameter of the second coolant supply path is equal to or less than a diameter of the first coolant supply path;
The drill in which the diameter of the third coolant supply path is smaller than the diameter of the second coolant supply path. Each of the first coolant jets, the cutting edge, and the groove are provided in pairs,
One of the first coolant jets is provided near the outer corner of one of the blade edges,
The other first coolant jet is provided in the vicinity of the outer corner of the other cutting edge.
The drill according to claim 1. The cutting part is
A fourth coolant supply path connected to the second coolant supply path;
A second coolant jet port connected to the fourth coolant supply path,
Two second coolant jets are provided;
The drill according to claim 1 or claim 2. The coolant jetted from the first coolant jet is a high pressure of 7 MPa or more and 30 MPa or less,
The drill according to any one of claims 1 to 4.