Modular drill and method for using a modular drill

A modular drill including a shank having a shank bore therein, a guide pin tip disposed in the shank bore, a cutting tip, and a connection shaft coupled to the cutting tip, the connection shaft having a connection shaft sidewall and a guide path therein for guiding the guide pin tip therethrough while the connection shaft moves through the shank bore.

FIELD

The present application relates to the field of modular drills.

BACKGROUND

According to the related art, there are modular drills having a shank and a cutting tip clamped in the shank. A challenge with these related art modular drills include that a clamping force can be reduced due to high cutting forces during a drilling process, thermal variations, side forces or vibration, thereby loosening the cutting tip or reducing a life of the cutting tip.

Accordingly, those skilled in the art continue with research and development in the field of modular drills.

SUMMARY

In one embodiment, a modular drill includes a shank having a shank bore therein, a guide pin tip disposed in the shank bore, a cutting tip, and a connection shaft coupled to the cutting tip. The connection shaft has a guide path therein for guiding the guide pin tip therethrough while the connection shaft moves through the shank bore.

In an aspect, the shank includes a plurality of shank flutes. In another aspect, the cutting tip includes a plurality of cutting tip flutes. In yet another aspect, the shank includes a plurality of shank flanks for clamping the cutting tip therebetween. In yet another aspect, the plurality of shank flanks each include a flank front surface and flank back surface. In yet another aspect, the cutting tip includes a cutting tip shoulder surface and a cutting tip counter surface. In yet another aspect, the modular drill further includes a locking pin. In yet another aspect, the shank includes a locking pin through hole. In yet another aspect, the connection shaft includes a locking pin engagement feature.

In another embodiment, a method for using a modular drill includes moving a connection shaft through a shank bore of a shank, the connection shaft being coupled to a cutting tip, the connection shaft having a guide path therein, and guiding a guide pin tip, which is disposed in the shank bore, through the guide path while the connection shaft moves through the shank bore of the shank.

In an aspect, moving the connection shaft through the shank bore of the shank includes inserting the connection shaft into the shank bore to assemble the modular drill. In another aspect, moving the connection shaft through the shank bore of the shank includes removing the connection shaft from the shank bore to disassemble the modular drill.

Other embodiments of the disclosed modular drill and method for using a modular drill will become apparent from the following detailed description, the accompanying drawings and the appended claims.

DETAILED DESCRIPTION

In one embodiment of the present disclosure, a modular drill includes a shank having a shank bore therein, a guide pin tip disposed in the shank bore, a cutting tip, and a connection shaft coupled to the cutting tip. The connection shaft has a guide path therein for guiding the guide pin tip therethrough while the connection shaft moves through the shank bore.

FIGS.1to11illustrate one exemplary modular drill of the present disclosure.

Referring toFIGS.1to3, the exemplary modular drill10includes a shank100, a guide pin200, a cutting tip300, a connection shaft400, and a locking pin500. The modular drill10defines an axial direction12and a rotational direction14.

The shank100includes an upper shank end102, a lower shank end104opposite the upper shank end, and a shank sidewall106between the upper shank end102and the lower shank end104. The shank sidewall106defines a plurality of shank flutes108that extend about the shank sidewall106. The plurality of shank flutes108can vary in size, shape and number of flutes. The plurality of shank flutes108may aid in removal of waste material during a cutting process.

The shank100further includes a shank pocket110for seating the cutting tip300and includes shank flanks120at opposing sides of the shank pocket110for clamping the cutting tip300therebetween. An interior side of the shank flanks120include a flank front surface122and a flank rear surface124.

The shank100further includes a shank bore130for receiving the connection shaft400therein. The shank further includes a guide pin hole140defining an opening to the shank bore130and a locking pin through hole150extending from the shank sidewall106to the shank bore130. The locking pin through hole150is preferably a cylindrical hole, more preferably a threaded hole.

The shank100may be manufactured from a comparatively inexpensive material having a moderate hardness, such as steel or another metal.

Referring toFIG.1, the guide pin200includes a guide pin front end202, a guide pin rear end204, and guide pin sidewall206. The guide pin front end202defines a guide pin tip210. The guide pin tip210may be, for example, spherical, conical, or cylindrical.

The guide pin200may be manufactured from a comparatively inexpensive material having a moderate hardness, such as steel or another metal.

For ease of manufacture, the shank100and guide pin200are formed as separate components, and the guide pin200is inserted and fixed within the guide pin hole140of the shank100such that the guide pin tip210is disposed in the shank bore130. The guide pin200may be fixed within the guide pin hole140by any suitable process. By way of example, the guide pin200may be fixed within the guide pin hole140by providing an external thread around the guide pin200and an internal thread in the guide pin hole140and threading the guide pin200into the guide pin hole140. The guide pin200may remain fixed in the guide pin hole140indefinitely unless in case of replacement due to wear. Alternatively, it is possible to omit the guide pin200and the guide pin hole140. For example, the shank100and the guide pin tip210may be manufactured as a unitary component, such as by way of an additive manufacturing process.

The cutting tip300includes an upper cutting tip end302, a lower cutting tip end304opposite the upper cutting tip end302, and a cutting tip sidewall306between the upper cutting tip end302and the lower cutting tip end304. The cutting tip sidewall306defines a plurality of cutting tip flutes308that extend about the cutting tip sidewall306. When the cutting tip300is seated in the shank pocket110, each cutting tip flute308is aligned with a shank flute108.

The cutting tip sidewall306further includes a cutting tip shoulder surface320and a cutting tip counter surface330. When the cutting tip300is being positioned in the shank pocket110, the cutting tip shoulder surface320contacts the flank front surfaces122to elastically deform the shank flanks120radially outwardly. When the cutting tip shoulder surface320turns past the flank front surfaces122, the shank flanks120return towards their undeformed position to clamp the cutting tip300therebetween to hold the cutting tip300in a seated positioned in the shank pocket110. When the cutting tip300is in the seated position, the cutting tip counter surface330is positioned directly adjacent to the flank front surface122and the cutting tip shoulder surface320is positioned directly adjacent to the flank rear surface124.

The cutting tip sidewall306further includes cutting tip connection bore340for receiving the connection shaft400therein and cutting tip torquing features350to facilitate a turning of the cutting tip300. A custom wrench may be provided to engage with the cutting tip torquing features350to turn the cutting tip300.

The cutting tip300may be manufactured from a harder and more expensive material, such as carbide, cermet, ceramics, and the like, which provides a good chip-removing capacity, good machining precision and long service life. In other words, the cutting tip300functions as a wear part that can be discarded after wear-out, while the shank100can be re-used with a new cutting tip300.

The connection shaft400includes a connection shaft upper end402, a connection shaft lower end404opposite the connection shaft upper end402, and a connection shaft sidewall406between the connection shaft upper end402and the connection shaft lower end404. The connection shaft sidewall406defines an upper connection portion410for connecting to the cutting tip300by insertion of the upper connection portion410into the cutting tip connection bore340and a lower connection portion420for connecting to the shank100by insertion of the lower connection portion420into the shank bore130.

For ease of manufacture and cost-effectiveness, the cutting tip300and connection shaft400are formed as separate components, and the upper connection portion410of the connection shaft400is inserted and fixed within the cutting tip connection bore340such that the lower connection portion420extends below the lower cutting tip end304. The upper connection portion410of the connection shaft400may be fixed within the cutting tip connection bore340by any suitable process. By way of example, the upper connection portion410of the connection shaft400may be fixed within the cutting tip connection bore340by providing an external thread around the upper connection portion410and an internal thread in the cutting tip connection bore340and threading the upper connection portion410into the cutting tip connection bore340and preferably after applying glue to the threads. To maintain tolerances, the profiles of the lower connection portion420should be machined after fixing the connection shaft400to the cutting tip300. The connection shaft400as a separate component may be manufactured from a comparatively inexpensive material having a moderate hardness, such as steel or another metal. Alternatively, it is possible to manufacture the cutting tip300and connection shaft400as a unitary component.

The connection shaft400includes guide path430therein for guiding the guide pin tip210therethrough while the connection shaft400moves through the shank bore130. The guide path430includes a guide path entrance432, an axial guide path segment434, and a circumferential guide path segment436.

The connection shaft400further includes a locking pin engagement feature440for receiving the locking pin500. For example, the locking pin engagement feature440may be a hole or notch in the connection shaft400. In the case of a hole, the hole is preferably oblong to compensate for manufacturing tolerances.

The locking pin500including a locking pin tip502, which may be, for example spherical, conical, or cylindrical. The locking pin500may be manufactured from a comparatively inexpensive material having a moderate hardness, such as steel or another metal.

It would be understood that the illustrated locking pin mechanism is one of many possibilities for locking the connection shaft400to the shank100. The present disclose may include any locking mechanism for locking the connection shaft400to the shank100. Alternatively, the locking mechanism may be omitted. The cutting tip300can be firmly held within the shank pocket110by the shank flanks120and engagement of the guide pin tip212with the guide path430while the modular drill10is cutting in the rotational direction14.

A method for using a modular drill is described with reference toFIGS.7to11.

As shown inFIGS.7A and7B, to assemble the modular drill, the cutting tip300and connection shaft400, which is coupled to the cutting tip, are starting to be inserted into the shank100. Thus, the cutting tip300is positioned between the shank flanks120and the connection shaft400is inserted into the shank bore130. Meanwhile, the guide pin tip210is guided into the guide path entrance432of the guide path430.

As shown inFIGS.8A and8B, the cutting tip300and connection shaft400further inserted into the shank100in the axial direction12. Meanwhile, the guide pin tip210is guided in axial direction12through the axial guide path segment434of the guide path430.

As shown inFIGS.9A and9B, the cutting tip300and connection shaft400are inserted further into the shank100and rotated clockwise with respect to the shank100in rotational direction14. The guide pin tip210is guided in both axial direction12and rotational direction14through the circumferential guide path segment436of the guide path430. Meanwhile, during rotation of the cutting tip300, the cutting tip shoulder surface320contacts the flank front surfaces122to deform the shank flanks120radially outwardly.

As shown inFIGS.10A and10B, the cutting tip300and connection shaft400are inserted further into the shank100and rotated clockwise with respect to the shank100in rotational direction14. Meanwhile, the cutting tip shoulder surface320passes the flank front surfaces122and the shank flanks120return towards their undeformed position to clamp the cutting tip300therebetween to hold the cutting tip300in a seated positioned in the shank pocket110. In the seated position, the cutting tip counter surface330is positioned directly adjacent to the flank front surface122and the cutting tip shoulder surface320is positioned directly adjacent to the flank rear surface124. Thus, the cutting tip300can be firmly held within the shank pocket110by the shank flanks120and engagement of the guide pin tip212with the guide path430while the modular drill10is cutting clockwise in the rotational direction14.

As shown inFIGS.11A,11B,12A, and12B, the cutting tip300and connection shaft400remain at the final position and the locking pin500is inserted through the shank100and into engagement with the connection shaft400.

To disassemble the modular drill10, the order ofFIGS.7to11can be viewed in reverse.

As shown inFIGS.11A,11B,12A, and12B, the cutting tip300and connection shaft400are at seated position and the locking pin500is removed from engagement with the connection shaft400and from the shank100. If the locking pin500is omitted, the disassembly the modular drill10may start atFIGS.10A and10B.

As shown inFIGS.9A and9B, the cutting tip300and connection shaft400are pulled away the shank100in the axial direction12and rotated counterclockwise with respect to the shank100in the rotational direction14. The guide pin tip210is guided in both axial direction12and rotational direction14through the circumferential guide path segment436of the guide path430. Meanwhile, during rotation of the cutting tip300, the cutting tip shoulder surface320contacts the flank front surfaces122to deform the shank flanks120radially outwardly.

As shown inFIGS.8A and8B, the cutting tip300and connection shaft400are pulled further away the shank100in the axial direction12and rotated counterclockwise further with respect to the shank100in the rotational direction14. The guide pin tip210is guided in both axial direction12and rotational direction14further through the circumferential guide path segment436of the guide path430. Meanwhile, the cutting tip shoulder surface320passes the flank front surfaces122and the shank flanks120return towards their undeformed position.

As shown inFIGS.7A and7B, the cutting tip300and connection shaft400, which is coupled to the cutting tip are pulled further away the shank100in the axial direction12. Meanwhile, the guide pin tip210is guided out of the guide path entrance432of the guide path430. To complete the disassembly of the modular drill, the cutting tip300and connection shaft400are removed from the shank100. Thus, the cutting tip300is pulled away from between the shank flanks120and the connection shaft400is pulled out of the shank bore130.

Thus, to assemble the modular drill10, the cutting tip300is rotated clockwise in direction14, and the cutting tip300is correspondingly pulled down in axial direction12due to the contact of guide pin tip210and the guide path430. To disassemble the modular drill10, the cutting tip300is rotated counterclockwise in direction14, and the cutting tip300is correspondingly pushed up in axial direction12due to the contact of guide pin tip210and the guide path430, and the cutting tip300can be removed from the shank100.

Advantages of the modular drill of the present disclosure may include ease of removing and inserting of the cutting tip, high stiffness and reliability of retaining of the cutting tip within the modular drill, and the use of conventional materials.

Although various embodiments of the disclosed modular drill have been shown and described, modifications may occur to those skilled in the art upon reading the specification. The present application includes such modifications and is limited only by the scope of the claims.