JP2018075648A - Gun drill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gun drill which inhibits bending during deep hole processing.SOLUTION: A gun drill includes: a cutting part having a blade edge; a base end part attached to a gun drill machine; and a shaft part connecting the cutting part with the base end part. In each of the cutting part and the shaft part, a groove part for discharging swarf is formed on a side surface. The base end part and the shaft part respectively have circulation paths in which the fluid flows. The cutting part includes: a first jet port which jets the fluid through the circulation path; a first through hole continuing into the first jet hole; and a cylindrical member which is fitted in the first through hole and includes a through hole having a cross section smaller than that of the first jet hole.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a gun drill used for deep hole machining, and more particularly to a gun drill that ejects fluid at high pressure.

  Conventionally, a gun drill machine has been used for machining deep holes in workpieces. The gun drill machine is used with a long gun drill attached to the spindle of the machine body.

  In this type of gun drill, a coolant discharge that communicates with the coolant supply path at the tip end of a hollow shank portion having a chip discharge groove having a V-shaped cross section along the longitudinal direction on the outer surface and having the inside as a coolant supply path. A gun drill equipped with a cutting head having an outlet is disclosed (for example, Patent Document 1).

  This gun drill drills deep holes in the workpiece by moving it forward and backward in the axial direction while rotating the gun drill toward the workpiece. At this time, coolant is sprayed from the coolant discharge port, and machining is performed while cooling the tip of the cutting head. In the conventional gun drill, the coolant is injected at a pressure of 1 MPa to 5 MPa, and even a high pressure is less than 7 MPa.

JP 2013-139059 A

  However, since the gun drill is generally long, there is a problem that the deflection of the deep hole to be machined becomes large due to large runout when the gun drill rotates. Conventionally, as a means to suppress such bending, a tool called a whip guide that guides the position of the shank is used separately, or the speed of deep hole processing is suppressed, that is, the gun drill is moved straight ahead slightly. It was handled by repeating the work of retreating. In this way, in deep hole machining using a gun drill, it is important to reduce bending and suppress runout during rotation.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a gun drill that suppresses runout of the gun drill and realizes high-precision deep hole machining.

  In order to solve the above problems, a gun drill according to the present invention includes a cutting portion having a cutting edge, a base end portion attached to a gun drill machine, and a shaft portion connecting the cutting portion and the base end portion, and the cutting A groove part for discharging chips is formed on the side surface of the part and the shaft part, the base end part and the shaft part have a flow path through which fluid passes, and the cutting part supplies fluid to the tip part. A first jet port that ejects; a first through hole that follows the first jet port; a jet port that is fitted in the first through hole and has a smaller cross section than the first jet port; And a cylindrical member.

  According to this configuration, the pressure of the fluid to be ejected is increased because the area from which the fluid is ejected is smaller than in the prior art. At the same time, the pressure in the distribution channel inside the gun drill is increased, so that the gun drill is prevented from shaking and high-precision deep hole machining is realized. This is the same principle that the higher the pressure of the water flowing in the hose, the more the hose is suppressed.

  Further, the gun drill has a cutting section in which the second injection port, the second through-hole that follows the second injection port, and the second through-hole are inserted into the injection hole having a smaller cross section than the second injection port. It is good also as a structure further provided with the cylindrical member which comprises an exit and the through-hole which follows this.

  Further, in this gun drill, it is preferable that the diameter of the cross section of the jet outlet of the cylindrical member is 0.6 mm or more and 2.0 mm or less, and the fluid is jetted at 7 MPa or more and 30 MPa or less. According to this configuration, high-precision deep hole drilling can be realized by suppressing gun drill swinging.

  In this gun drill, it is preferable that the diameter of the jet outlet of the cylindrical member is between 1/2 and 1/5 of the diameter of the first jet outlet, and the fluid is jetted at 7 MPa or more and 30 MPa or less. . According to this configuration, a high-pressure fluid can be ejected from the ejection port, and at the same time, the pressure in the pipe is increased, so that the gun drill can be prevented from shaking and high-precision deep hole machining can be realized.

  Further, in this gun drill, the cutting portion and the cylindrical member are metal, and the cutting portion and the cylindrical member are disposed between the wall surface of the first through hole or the second through hole and the side surface of the cylindrical member. It is preferable that an alloy different from the cylindrical member is interposed. According to this configuration, the cylindrical member is firmly and securely fixed to the first ejection hole or the second ejection hole of the cutting portion, and can sufficiently withstand high pressure.

  A cylindrical member according to the present invention includes a cutting portion having a cutting edge, a base end portion attached to a gun drill machine, and a shaft portion connecting the cutting portion and the base end portion, and the cutting portion and the shaft portion are side surfaces. A groove portion for discharging chips is formed, the base end portion and the shaft portion have a flow passage through which fluid passes, and the cutting portion has a jet outlet for ejecting fluid through the flow passage. A member that is used by being attached to a gun drill and that has a through-hole that follows, and is fitted in the through-hole and has a jet port smaller than the jet port.

  The gun drill according to the present invention includes a cutting portion having a cutting edge, a base end portion attached to a gun drill machine, and a shaft portion connecting the cutting portion and the base end portion, and the cutting portion and the shaft portion include: A groove portion for discharging chips is formed on a side surface, the base end portion and the shaft portion have a flow path through which a fluid passes, and the cutting portion includes a jet outlet A for ejecting fluid to the tip portion, and , A through hole A extending to the base end side opposite to the tip end portion following the jet port A, and a pipe passage A extending to the base end portion following the through hole A and having a larger cross-sectional area than the through hole A. And.

  This gun drill is claimed in the present application in that it has two types of pipe passages (through-hole A and pipe passage A) having a smaller area for ejecting fluid than before and the inside of the cutting portion having different cross-sectional areas. This is common with the first invention. With this configuration, the pressure of the fluid to be ejected is higher than before, and at the same time, the pressure in the flow path inside the gun drill is increased, so that the gun drill is prevented from shaking and high-precision deep hole machining is realized.

  Further, in this gun drill, the cutting part includes a spout B for ejecting a fluid to a front end, a through hole B extending to the base end side opposite to the front end after the spout B, and the through hole It is good also as a structure further provided with the pipe channel | path B larger in cross-sectional area than the said through-hole B extended to the base end part following B.

  Further, in this gun drill, it is preferable that the diameter of the ejection port A is 0.6 mm or more and 2.0 mm or less, and the fluid is ejected at 7 MPa or more and 30 MPa or less.

  In this gun drill, it is preferable that the diameter of the ejection port A is between 1/6 and 1/30 of the outer diameter of the cutting portion, and the fluid is ejected at 7 MPa or more and 30 MPa or less. The diameter of the conventional gun drill outlet is about 1/3 to 1/5 of the outer diameter of the cutting part. According to this configuration, a high-pressure fluid can be ejected from the outlet and at the same time the pressure in the pipe increases. , Suppresses gun drill shaking and realizes high-precision deep hole machining.

  As described above, according to the gun drill according to the present invention, by increasing the pressure of the flow path inside the gun drill, it is possible to suppress the deflection of the gun drill and perform high-precision deep hole machining.

It is a perspective view which shows the gun drill which concerns on one Embodiment of this invention. (A) is a perspective view which shows the front-end | tip part of the same gun drill. (B) is a plan view. (C) is a partially broken side view. It is sectional drawing of the same gun drill. (A) is a perspective view which shows the front-end | tip part of the gun drill which concerns on another embodiment. (B) is a plan view. (C) is a partially broken side view. It is sectional drawing of the gun drill which concerns on another embodiment. (A) is a top view which shows the front-end | tip part of the gun drill which concerns on another embodiment. (B) is a partially broken side view of a gun drill according to another embodiment.

<1. Gun Drill Structure>
Hereinafter, embodiments according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments. As shown in FIG. 1, the gun drill 1 is configured to be long and has a hollow shaft portion 3, a cutting portion 2 disposed at one end portion thereof, a proximal end portion 4 disposed at the other end portion thereof, Is provided as a main component. In addition, the gun drill 1 of this embodiment is a circular cross section whose length is about 800 mm and whose shaft part 3 is about 15 mm in diameter as an example. The cutting part 2, the shaft part 3, and the base end part 4 are all made of metal, and as an example, are made of SK material.

  2A and 2B are views showing the distal end portion of the gun drill 1 of the present embodiment, wherein FIG. 2A is a perspective view, FIG. 2B is a plan view, and FIG. 2C is a partially broken side view. As shown in FIG. 2, the cutting portion 2 has a cutting edge 21 at the tip, a V-shaped groove portion 22 is formed along the longitudinal direction of the gun drill 1, and a cross section is partially cut out from a circle. Shape. The groove portion 22 is for discharging chips of the work cut out by the cutting edge 21 to the base end portion 3 side.

  Further, a jet outlet 23 a for jetting coolant is provided on the front end surface of the cutting portion 2, and a through hole 23 is formed from the jet outlet 23 a to the flow path 31 of the shaft portion 3. The jet outlet 23a in the present embodiment is formed in a circular shape having a diameter of 5 mm, but is not limited thereto, and may be an elliptical shape or other shapes.

  Further, as shown in FIG. 2C, a cylindrical member 24 having a through hole 24 a is fixed to the through hole 23 of the cutting part 2. And the front end surface of the through-hole 24a becomes the jet outlet 24b which ejects a coolant. An alloy 25 is interposed between the wall surface of the through hole 23 and the side wall of the cylindrical member 24, and the cylindrical member 24 is securely fixed to the through hole 23 by the alloy 25. In addition, the material of the cutting part 2 and the cylindrical member 24 consists of a hard material as an example, and an alloy is alloy steel, an industrial diamond, an alumina etc. as an example.

  In addition, the cross-section of the through hole 24a of the present embodiment is, for example, a circle having a diameter of 1.5 mm. . Further, the through hole 24a of the present embodiment is configured in a tubular shape having a constant cross section from the distal end to the proximal end side, but is not limited thereto, and may be a conical configuration in which the cross section gradually widens from the distal end to the proximal end side. If the conical configuration is used, the pressure loss can be suppressed more than the tubular shape.

  FIG. 3 is a cross-sectional view of the gun drill 1 of the present embodiment. As shown in FIG. 3, the cutting part 2 is connected to one end of the shaft part 3. The shaft portion 3 is cylindrical, has a V-shaped groove portion 32 formed along the longitudinal direction of the gun drill 1, and has a shape in which a cross section is cut out from a circular shape. The groove portion 32 is connected to the groove portion 22 of the cutting portion 2, and is for discharging the work chips cut by the cutting edge 21 to the base end portion 3 side.

  In addition, the shaft portion 3 is formed with a flow path 31 along the longitudinal direction in which coolant can flow in the center. The cross-sectional shape of the flow path 31 is substantially the same as the cross-sectional shape of the through hole 23 of the cutting part 2, and the end of the flow path 31 and the end of the through hole 23 are smoothly connected. Thereby, the resistance of the coolant flowing inside the gun drill 1 is reduced, and the pressure loss is suppressed.

  As shown in FIG. 3, a base end portion 4 is connected to the other end portion of the shaft portion 3. The base end portion 4 has a cylindrical shape, and a flow path 41 is formed in the center along the longitudinal direction through which coolant can flow. The cross-sectional shape of the flow path 41 is substantially the same as the cross-sectional shape of the flow path 31 of the shaft portion 3, and the end of the flow path 31 and the end of the flow path 41 are smoothly connected. In addition, the base end portion 4 has a part of the outer peripheral side wall cut out and is provided with a screw hole 42. The screw hole 42 is used to securely fix the gun drill 1 to the gun drill machine when attaching the gun drill 1 by connecting the base end 3 to a gun drill machine (not shown).

  The gun drill machine is provided with a pump (not shown) for supplying coolant to the gun drill 1. The pump is a 5.5 kw pump used for a general gun drill. The coolant is supplied to the gun drill 1 by the pump, and the coolant is ejected from the ejection port 24 b through the flow paths 31 and 41. In the present embodiment, the pressure of the coolant ejected from the ejection port 24b is, for example, 15 MPa. However, the pressure of the coolant to be ejected is not limited to this, and may be 7 MPa to 30 MPa. Becomes extremely high pressure.

  The gun drill 1 is attached to a gun drill machine so as to be rotatable and movable back and forth along the longitudinal direction. Thereby, the gun drill 1 moves forward while rotating, and the workpiece is cut and deep hole machining is performed. Simultaneously with the cutting of the workpiece, coolant is ejected from the ejection port 24 b, cutting the workpiece chips while cooling the cutting portion 2, and discharging the chips from the groove portion 22.

<2. Effects of this embodiment>
The gun drill 1 of this embodiment has the following effects by the above structure.
In the gun drill 1, the cylindrical member 24 is attached to the through hole 23 of the cutting portion 2, and the coolant is ejected from the through hole 24 b smaller than the ejection port 23 a, so that high-pressure coolant is ejected. At the same time, the pressure of the coolant flowing through the flow paths 31 and 41 and the through hole 24a in the gun drill 1 becomes high, and the deflection of the gun drill 1 is suppressed, so that bending during deep hole processing can be suppressed. This is similar to the fact that when the pressure of water or blood flowing through the hose or blood vessel increases, the hose or blood vessel becomes hard and bending is suppressed.

  This makes it possible to perform deep hole drilling with higher accuracy than before, and the machining speed is greatly improved. Specifically, the processing speed is approximately twice to seven times that of the prior art. In addition, the pump that supplies the coolant may remain the same as before, and this can be realized at low cost without using a high-pressure, high-performance pump. Further, since the high-pressure coolant is ejected from the ejection port 24b, the workpiece chips are cut into small pieces at a short dimension, and flow into the groove portion 22 together with the coolant, and the chips are discharged smoothly. As a result, clogging of chips is suppressed, chip discharge is smooth, and efficient deep hole machining can be performed.

<3. Another embodiment>
Next, a gun drill according to an embodiment different from the above embodiment will be described. The main difference between the gun drill 100 of this embodiment and the gun drill 1 of the said embodiment is that the number of the jet nozzles which eject the coolant in a cutting part is two. Hereinafter, this difference will be mainly described, the description of the same parts as the gun drill 1 will be omitted, and the same reference numerals will be used for the same configurations.

  Fig.4 (a) is a perspective view which shows the front-end | tip part of the gun drill 100 which concerns on this embodiment. (B) is a plan view. (C) is a partially broken side view. As shown in FIG. 4, the cutting part 120 has a cutting edge 121 at the tip, a V-shaped groove part 122 is formed along the longitudinal direction of the gun drill 100, and the cross-section is partially cut out from a circular shape. Shape. The groove part 122 is for discharging the chips of the work cut by the cutting edge 121 to the base end part 3 side.

  Further, a first jet port 123a and a second jet port 124a for jetting coolant are provided on the front end surface of the cutting unit 120, and a through hole 123 extending from the jet port 123a to the flow path of the shaft portion 3; A through hole 124 extending from the jet outlet 124 a to the flow path of the shaft portion 3 is formed.

  Further, as shown in FIG. 4C, a cylindrical member 125 having a through hole 125 a is fixed to the through hole 123 of the cutting part 120. A cylindrical member 126 having a through hole 126a is fixed to the through hole 124 of the cutting part 120. The front end surfaces of the through holes 125a and 126a serve as the jet outlets 125b and 126b for jetting the coolant, respectively. Further, an alloy 127 is interposed between the wall surfaces of the through holes 123 and 124 and the side walls of the cylindrical members 125 and 126, and the alloy 127 ensures that the cylindrical members 125 and 126 are respectively inserted into the through holes 123 and 124. It is fixed.

  Further, the through holes 123 and 124 are connected to the flow path 31 of the shaft portion 3, and the coolant is jetted from the jet outlets 125 b and 126 b through the flow path 31. The shaft portion 3 may include two flow paths, and the two flow paths may be connected to the two through holes 123 and 124, respectively.

  Next, a gun drill according to another embodiment will be described. The main difference between the gun drill 200 of this embodiment and the gun drill 1 of the above embodiment is the presence or absence of a cylindrical member. In the gun drill 200 of this embodiment, the cutting part 220 does not include a cylindrical member. Hereinafter, this difference will be mainly described, the description of the same parts as the gun drill 1 will be omitted, and the same reference numerals will be used for the same configurations.

  FIG. 5 is a cross-sectional view of the gun drill 200 according to the present embodiment. As shown in FIG. 5, the cutting part 220 includes an ejection port 221 that ejects fluid to the distal end, a through hole 222 that extends to the base end side, and a pipe passage that extends to the base end side. 223. The through hole 222 has substantially the same diameter as the jet port 221, and the pipe passage 223 is configured to have a larger diameter than the through hole 222.

  In addition, the wall of the connecting portion between the through hole 222 and the pipe passage 223 is rounded so that the fluid flows smoothly. Note that the radius may be further increased, or the through hole 222 may be formed in a conical shape that squeezes toward the ejection port 221. Further, the flow of the fluid can be smoothly configured so that the wall of the connection portion between the flow path 31 and the pipe passage 223 of the shaft portion 3 is also largely rounded.

  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 shape of the ejection port is not limited to a circle, and may be an ellipse or other shapes (see FIG. 6A). Further, the shape of the through hole of the cylindrical member is not limited to a constant cross section, and may be a conical through hole (see FIG. 6B). Therefore, such a thing is also included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Gun drill 2 Cutting part 21 Cutting edge 22 Groove part 23 Through-hole 23a Outlet 24 Cylindrical member 24a Through-hole 24b Outlet 25 Alloy 3 Shaft part 31 Flow path 32 Groove part 4 Base end part 41 Flow path 42 Screw hole 100 Gun drill 120 Cutting part 121 Cutting edge 122 Groove 123 First through hole 123a First outlet 124 Second through hole 124a Second outlet 125, 126 Cylindrical members 125a, 126a Through holes 125b, 126b Outlet 200 Gun drill 220 Cutting part 221 Outlet 222 Through Hole 223 Pipe passage

Claims (10)

A cutting part having a cutting edge;
A proximal end attached to the gun drill machine;
A shaft portion connecting the cutting portion and the base end portion,
The cutting part and the shaft part are formed with a groove part for discharging chips on the side surface,
The base end portion and the shaft portion have a flow path through which a fluid passes,
The cutting part is
A first outlet for ejecting fluid to the tip;
A first through hole following the first jet port;
A cylindrical member fitted in the first through hole and having a jet port having a smaller cross section than the first jet port and a through hole following the jet port,
Gun drill. The cutting part is
A second spout,
A second through hole continuing to the second jet port;
A tubular member fitted in the second through-hole, and having a jet outlet having a smaller cross section than the second jet outlet and a through-hole subsequent thereto,
The gun drill according to claim 1. The diameter of the cross section of the outlet of the tubular member is 0.6 mm or more and 2.0 mm or less,
The fluid is ejected at 7 MPa or more and 30 MPa or less,
The gun drill according to claim 1 or 2. The diameter of the outlet of the tubular member is between 1/2 and 1/5 of the diameter of the first outlet;
The fluid is ejected at 7 MPa or more and 30 MPa or less,
The gun drill according to claim 1 or 2. The cutting part and the cylindrical member are metal,
An alloy different from the cutting portion and the cylindrical member is interposed between the wall surface of the first through hole or the second through hole and the side surface of the cylindrical member.
The gun drill according to any one of claims 1 to 4. A cutting portion having a cutting edge, a base end portion attached to a gun drill machine, and a shaft portion connecting the cutting portion and the base end portion,
The cutting part and the shaft part are formed with a groove part for discharging chips on the side surface, the base end part and the shaft part have a flow path through which the fluid passes, and the cutting part passes through the flow path. A member used by being attached to a gun drill having a jet port for ejecting a fluid and a through hole following the jet port,
It is fitted in the through-hole, and has a jet port having a smaller cross section than the jet port,
A cylindrical member. A cutting part having a cutting edge;
A proximal end attached to the gun drill machine;
A shaft portion connecting the cutting portion and the base end portion,
The cutting part and the shaft part are formed with a groove part for discharging chips on the side surface,
The base end portion and the shaft portion have a flow path through which a fluid passes,
The cutting part is
A spout A for ejecting fluid to the tip,
A through-hole A extending to the base end side opposite to the tip end, following the jet outlet A;
A tube passage A extending to the base end portion following the through hole A and having a larger cross-sectional area than the through hole A,
Gun drill. The cutting part is
A spout B for ejecting fluid to the tip;
A through-hole B extending to the base end side opposite to the tip end, following the jet outlet B;
A pipe passage B extending to the base end portion following the through hole B and having a larger cross-sectional area than the through hole B;
The gun drill according to claim 7. The diameter of the jet outlet A is 0.6 mm or more and 2.0 mm or less,
The fluid is ejected at 7 MPa or more and 30 MPa or less,
The gun drill according to claim 7 or 8. The diameter of the ejection port A is between 1/6 and 1/30 of the outer diameter of the cutting portion;
The fluid is ejected at 7 MPa or more and 30 MPa or less,
The gun drill according to claim 7 or 8.

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