WO2017126145A1

WO2017126145A1 - Hob

Info

Publication number: WO2017126145A1
Application number: PCT/JP2016/072883
Authority: WO
Inventors: 悠治今宮; 雅信三▲崎▼
Original assignee: 三菱重工工作機械株式会社
Priority date: 2016-01-22
Filing date: 2016-08-04
Publication date: 2017-07-27
Also published as: JP2017127947A

Abstract

The purpose of the present invention is to provide a hob capable of further increasing cutting speed while maintaining tool service life. A hob in which a cylindrical hob body (1a) with an axial hole (1aaa) through which coolant passes is integrated with multiple cutting parts (23) formed along a helical screw thread (21) on the outer circumference of the hob body (1a) by grooves (22) that extend in the axial direction of the hob body (1a). The cutting parts (23): have a cutting face (25) for cutting a workpiece, a flank (26) for removing workpiece trimmings, and a cutting edge (24) that forms the line of intersection between the cutting face (25) and the flank (26); and have communication holes (30) provided so as to bring the back surface (23b) of the cutting part (23) into communication with the axial hole (1aaa) of the hob body (1a). The hob is configured so that the openings of the communication holes (30) on the back surface (23b) of the cutting parts (23) face the cutting edges (24) of the cutting parts (23).

Description

Hob

The present invention relates to a hob.

Hobbing is used for roughing and finishing gears in power transmission gear processing for automobiles, construction machinery, industrial machinery, ships and aircraft. As the hob material, for example, high-speed tool steel or cemented carbide is used.

There are two types of hob cutting methods: dry cutting that does not use coolant (cutting oil or cutting water) and wet cutting that uses the coolant. In the wet cut, as shown in FIG. 5, coolant 111 is discharged from an injection port (not shown) installed in the machine, and an intersection line between the rake face 105 and the flank face 106 in the blade portion 103 of the hob 101. The cutting blade 104 is applied to the cutting portion of the work (workpiece) to be cut, so that the cutting waste is efficiently discharged and the cutting heat is efficiently removed. Therefore, the upper limit of the cutting speed in the wet cut is higher than that in the dry cut.

In the following Patent Document 1, a plurality of segments are connected in the axial direction by a drawing bolt to form a cylindrical milling body, a plurality of milling inserts provided in a spiral shape on the outer periphery of the cylinder, A milling tool comprising a branch duct for the supply of cooling medium from the cooling medium duct to the milling insert is disclosed.

JP 2013-233648 A

By the way, there is an increasing demand for further improvement in productivity by cutting with the hob described above, and further increases in the cutting speed are being studied. However, when the cutting speed is increased, the cutting heat increases accordingly, and even in the case of a wet cut in which cutting is performed while supplying coolant from the injection port to the cutting location, the processing point Wa where the cutting edge 104 contacts the workpiece W. It was not possible to sufficiently cool the cutting portion including the. In other words, the cutting heat could not be sufficiently removed at the cutting location. As a result, softening of the base material of the hob progresses, wear on the rake face and flank face constituting the blade part of the hob progresses, and there is a problem that the tool life is shortened.

In the milling tool described in Patent Document 1, since a plurality of segments are connected by a drawing bolt, a workpiece is cut only at a slower cutting speed than a hob in which a plurality of blade portions are integrally formed. I could not.

As described above, the present invention has been made to solve the above-described problems, and provides a hob that can further increase the cutting speed while maintaining the tool life. The purpose is that.

The hob according to the first invention for solving the above-described problem is
A plurality of blades formed by a cylindrical hob body having a shaft hole through which coolant flows, and a groove extending in the axial direction of the hob body along a spiral screw thread at the outer periphery of the hob body The hob adjacent to a plurality of blade portions in the axial direction of the hob,
The blade portion includes a rake face that cuts the workpiece, a flank face that excludes the cut workpiece, and a cutting edge that forms a line of intersection between the rake face and the flank face,
A communication hole provided in communication between the back surface of the blade and the shaft hole of the hob;
An opening on the back surface side of the blade portion in the communication hole is opposed to the cutting edge of the blade portion.

In addition, the communication hole is provided in the groove in a radial direction extending in the radial direction and provided in a back surface portion of the blade portion, communicates with the radial hole portion, and is inclined with respect to the radial direction. And an inclined hole portion extending.

Further, the communication hole is characterized by opening at a location along the screw thread.

According to the present invention, the blade portion includes a rake face that cuts the workpiece, a flank surface that excludes the cut workpiece portion, and a cutting edge that forms a line of intersection between the rake face and the flank surface. An opening on the back surface side of the blade portion in the communication hole is provided in the communication hole, the communication hole provided in communication with the back surface portion of the blade portion and the shaft hole of the hob. By facing the rake face, the coolant flowing through the shaft hole is supplied to the vicinity of the cutting edge of the blade portion from the opening on the back surface portion of the blade portion through the communication hole. As a result, the coolant can be directly supplied to the cutting location including the processing point of the workpiece that is in contact with the cutting edge, and the cutting location is sufficiently cooled as compared with the case where the coolant is supplied from the outside of the workpiece to the cutting location. be able to. Therefore, the cutting speed can be further increased as compared with the case where the coolant is supplied from the outside of the workpiece to the cutting location while maintaining the tool life.

It is a side view of the hob which concerns on 1st embodiment of this invention. It is a front view of the said hob. FIG. 3 is an enlarged view of a surrounding line III in FIG. 2. It is the schematic of the coolant supply apparatus which supplies a coolant to the said hob. It is a figure for demonstrating the state which cut | disconnects a workpiece | work with the conventional hob.

Embodiments of a hob according to the present invention will be described with reference to the drawings, but the present invention is not limited to only the following embodiments described with reference to the drawings.

[First embodiment]
A hob according to a first embodiment of the present invention will be described with reference to FIGS. This embodiment demonstrates the case where it applies to a shank type hob.

A hob (shank type hob) 1 according to the present embodiment is a tool for machining a gear having a predetermined helix angle on the outer surface of a workpiece (workpiece).

The hob body 1a of the hob 1 has a cylindrical shape having a central hole 1aaa through which the coolant 72 flows. As shown in FIG. 1, the hob main body 1a has a taper shank attachment portion (front support portion) 11, a cutting blade portion 20, and a straight shank attachment portion (rear support portion) 12 from the front end to the rear end. Is provided.

The front end side of the taper shank mounting portion 11 is tapered. The attaching part 11 of the taper shank is held by the hob head 53 of the hobbing machine 50.

The rear end side of the straight shank mounting portion 12 has a straight shape. The straight shank mounting portion 12 is held by the hob head 53 of the hobbing machine 50. That is, the shank type hob 1 is rotatably supported by the hob head 53 of the hobbing machine 50 by the straight shank mounting portion 12 and the tapered shank mounting portion 11 described above.

As shown in FIGS. 2 and 3, the cutting blade portion 20 has a plurality of blade portions 23 formed by a large number of grooves 22 extending in the axial direction of the hob main body 1 a along the spiral screw thread 21. . The blade portion 23 has a rake face 25, a flank face 26, and a cutting edge 24. The cutting edge 24 is an intersection line between the rake face 25 and the flank face 26. The rake face 25 forms a front side surface in the rotational direction of the hob body 1 a in the blade portion 23 in a direction along the screw thread 21.

Further, the cutting blade portion 20 is formed with a communication hole 30 for supplying the coolant 72 flowing through the center hole 1aaa of the hob body 1a to the vicinity of the cutting blade 24. The communication hole 30 has a first hole (radial hole) 31 and a second hole (inclined hole) 32.

The first hole 31 is provided in the bottom 22 a of the groove 22. The first hole 31 extends linearly in the radial direction of the hob body 1a, and communicates the bottom 22a of the groove 22 and the center hole 1aaa.

The second hole portion 32 is provided in the back surface portion 23 a of the blade portion 23. The second hole portion 32 extends linearly and has a shape that allows the back surface portion 23 a of the blade portion 23 and the first hole portion 31 to communicate with each other. The opening 32 a of the second hole portion 32 is provided so as to face the rake face 25 (the cutting edge 24) of the adjacent blade portion 23 in the direction along the screw thread 21. Thereby, the coolant 72 flowing through the center hole 1aaa flows through the first hole 31 and the second hole 32 in the communication hole 30 and flows out from the opening 32a of the second hole 32 to the outside of the hob body 1a. Will do. At this time, the hob main body 1 a is rotating, and the coolant 72 that has flowed outward from the opening 32 a of the second hole 32 of the communication hole 30 is cut by the blade 23 adjacent in the direction along the screw thread 21. 24 is supplied to the vicinity. The coolant 72 is supplied to the vicinity of the cutting edge 24 regardless of the position in the circumferential direction of the hob main body 1a. As a result, the cutting edge 24 that has not been able to directly supply the coolant from the nozzles in the machine and that contributes to the cutting process in contact with the workpiece, or the cutting that includes the machining point at which the cutting edge 24 is in contact with the workpiece. The coolant 72 can be directly supplied to the location.

Here, a hobbing machine capable of supplying the coolant 72 into the center hole 1aaa of the hob 1 while rotatably supporting the hob 1 described above will be described with reference to FIG.

As shown in FIG. 4, the hobbing machine 50 includes a hob head 53 that can hold the hob 1 at a predetermined angle while allowing the hob 1 to rotate, a column 52 that supports the hob head 53 so as to be movable up and down, and a bed 51 that supports the column 52. And have. The column 52 is provided with a nozzle 54. The nozzle 54 is arranged so that coolant supplied from a coolant supply device 60 described later can be discharged to a cutting location where the work is cut by the hob 1.

The hobbing machine 50 further includes a coolant supply device 60. The coolant supply device 60 includes a coolant tank 61, a feed pipe 62, a manifold 63, first and

second supply pipes

64 and 65, and a pump 66. A coolant 70 is stored in the coolant tank 61. The manifold 63 has one input-side port 63a and two output-side ports 63ba and 63bb.

One end side (tip end side) of the feeding pipe 62 is connected to the port 63 a on the input side of the manifold 63. The other end side (base end side) of the feed pipe 62 is disposed in the coolant tank 61. One end side (base end side) of the first supply pipe 64 is connected to the port 63ba on the output side of the manifold 63. The other end side (front end side) of the first supply pipe 64 is connected to the base end side of the nozzle 54. One end side (base end side) of the second supply pipe 65 is connected to the port 63bb on the output side of the manifold 63. The other end side (tip end side) of the second supply pipe 65 is connected to the center hole 1aaa of the hob 1 supported by the hob head 53 via the column 52 and the hob head 53. The pump 66 is provided in the middle of the feed pipe 62. Therefore, by driving the pump 66, the coolant 70 in the coolant tank 61 is supplied to the port 63 a on the input side of the manifold 63 via the feed pipe 62, branched by the manifold 63, and output from the manifold 63. To the ports 63ba and 63bb.

The coolant 71 that has flowed to the port 63ba on the output side of the manifold 63 flows through the first supply pipe 64 and is supplied to the nozzle. The coolant 72 that has flowed to the port 63bb on the output side of the manifold 63 flows through the second supply pipe 65 and is supplied to the center hole 1aaa of the hob 1.

The coolant 71 supplied to the nozzle 54 is discharged from the tip 54a of the nozzle 54 and hits a workpiece (not shown) to be cut by the hob 1. That is, the coolant 71 is supplied from the outside to the hob 1 and the workpiece. As a result, the hob 1 and the workpiece are cooled, and the cutting waste generated by the hob 1 cutting the workpiece is discharged from the cut portion to the outside.

Further, the coolant 72 supplied to the center hole 1aaa of the hob 1 passes through the first hole portion 31 and the second hole portion 32 of the communication hole 30, and the opening portion 32a of the second hole portion 32 (one opening portion of the communication hole). ) Will be discharged. At this time, since the hob 1 is rotating and cutting the workpiece, the coolant discharged from the opening 32a of the second hole 32 is in the region where the hob 1 is cutting the workpiece. The cutting edge 24 is supplied to a cutting location including a processing point in contact with the workpiece, and is supplied to the vicinity of the cutting edge 24 of the hob 1 in a region where the hob 1 is not cutting the workpiece.

Therefore, according to the hob 1 according to this embodiment, the hob 1 has the communication hole 30 provided so that the back surface part 23a of the blade part 23 and the center hole 1aaa of the hob 1 communicate with each other. The opening on the back surface portion 23 a side faces the rake face 25 of the blade portion 23, so that the coolant 72 that flows through the center hole 1 aaa of the hob 1 passes through the communication hole 30 and the back surface portion 23 a of the blade portion 23. Is supplied to the vicinity of the cutting edge 24 of the blade portion 23 from the opening portion. As a result, the coolant can be directly supplied to the cutting location including the machining point of the workpiece with which the cutting edge 24 comes into contact, and the cutting location is sufficiently cooled compared to the case where the coolant is supplied from the outside of the workpiece to the cutting location. can do. Therefore, the cutting speed can be further increased as compared with the case where the coolant is supplied from the outside of the workpiece to the cutting location while maintaining the tool life.

The communication hole 30 is provided in the groove 22 and extends in the radial direction in the first hole portion 31 and the back surface portion 23a of the blade portion 23. The communication hole 30 communicates with the first hole portion 31 and is inclined with respect to the radial direction. By having the extended second hole portion 32, the communication hole 30 itself can be processed from the outer peripheral portion side of the hob 1, and an increase in manufacturing cost of the hob 1 can be suppressed.

Directing the coolant 72 discharged from the communication hole 30 by providing the communication hole 30 at a location along the screw thread 21, and the coolant 72 discharged from the communication hole 30 is provided with the communication hole 30. The cutting edge 24 of the cutting edge 23 adjacent to the cutting edge 23 in the direction of the screw thread 21 and the cutting edge 24 adjacent to the cutting edge 24 and the cutting point including the processing point where the cutting edge 24 comes into contact with the workpiece can be efficiently applied. become. Thereby, cutting heat can be removed efficiently.

[Other Embodiments]
Although the shank type hob 1 has been described above, it can be applied to a hob having a hole to be attached to the arbor. Even such a hob has the same effects as the shank type hob 1 according to the first embodiment described above.

In the above description, the shank type hob 1 provided with the communication hole 30 communicating with the center hole 1aaa at the location along the screw line has been described. However, the communication hole communicating with the center hole is provided regardless of the screw line. A shank-shaped hob can also be used. This is a tool that cuts a workpiece by rotating the shank-shaped hob 1 itself in the circumferential direction. Therefore, the communication hole is adjusted by adjusting the flow rate when the coolant is discharged from the communication hole and the rotation speed of the hob. This is because the coolant discharged from the nozzle can be applied to the vicinity of the cutting edge of the blade portion.

The hob according to the present invention can cool the blade portion efficiently regardless of the position in the circumferential direction, and can be used extremely beneficially industrially.

1 hob (shank type hob), 1a hob body, 1aa, 1ab end, 1aaa center hole (shaft hole), 11 taper shank mounting, 12 straight shank mounting, 20 cutting blade, 21 screw thread, 22 Groove, 22a bottom part, 23 blade part, 24 cutting edge, 25 rake face, 26 flank face, 30 communication hole, 31 first hole part (radial hole part), 32 second hole part (inclined hole part), 32a opening Part, 50 hobbing machine, 51 bed, 52 column, 53 hob head, 54 nozzle, 60 coolant supply device, 61 coolant tank, 62 feed pipe, 63 manifold (branch pipe), 64 first supply pipe, 65 second Supply pipe, 66 pump

Claims

A plurality of blades formed by a cylindrical hob body having a shaft hole through which coolant flows, and a groove extending in the axial direction of the hob body along a spiral screw thread at the outer periphery of the hob body The hob adjacent to a plurality of blade portions in the axial direction of the hob,
The blade portion includes a rake face that cuts the workpiece, a flank face that excludes the cut workpiece, and a cutting edge that forms a line of intersection between the rake face and the flank face,
A communication hole provided in communication between the back surface of the blade and the shaft hole;
The opening on the back surface side of the blade portion in the communication hole faces the cutting blade of the blade portion.
The hob according to claim 1,
The communication hole is provided in the groove in a radial direction extending in the radial direction, and provided in a back surface portion of the blade portion, communicates with the radial hole portion, and extends inclined with respect to the radial direction. A hob comprising an inclined hole portion.
The hob according to claim 1,
The hob characterized in that the communication hole is opened at a location along the screw thread.
A hob according to claim 2, wherein
The hob characterized in that the communication hole is opened at a location along the screw thread.