Patent Description:
Generally, a boring machine may be used for precisely machining a hole of a long workpiece. The boring machine may include a boring bar having a long length configured to enter into an inner surface of the hole of the long workpiece. A tool for machining the inner surface of the hole may be installed at a front end of the boring bar. Further, the boring machine may include an apparatus for exchanging the tool for a new tool.

According to related arts, the exchanging apparatus may have a structure commonly used with a spindle exchanging apparatus. Thus, the tool installed at the front end of the boring bar may have a size substantially the same as a size of a tool installed at a spindle. In order to improve a performance of a damper in the boring machine, it may be required to reduce a weight of the tool at the front end of the boring bar. However, because the tool at the spindle may not have a vibration damping function, the tool may have a large size so that the tool at the front end of the boring bar may also have a large size.

In a type for exchanging a tool using a swing arm, a fixing force corresponding to the weight of the tool may be provided to the swing arm to prevent a falling of the tool. The fixing force may impact the boring bar having a long overhang in an exchanging process. Further, the swing arm may have long X-Y axis strokes due to a distance difference between the spindle and the boring bar regardless of a size of the workpiece for the exchanging process. When a large space for the swing arm may not be secured, the size of the workpiece may be restricted due to interference between the workpiece and the spindle.

<CIT> discloses a machine tool comprising a boring bar supporting device. According to this document, various standard tools to be demountable from a spindle and to be changed including a boring standard tool are constituted free to be demountably changed in the same way with respet to a boring bar main bodyto be supported and fixed on a boring bar installing part of a tool rest. A second tool supporting device free to demountably change the various standard tools from and a distal end of the boring bar main body is constituted such that a clamp working device provided with a first piston member to reciprocate in accordance with energizing force of a coil spring.

It is one object of the invention to provide an apparatus for exchanging a tool of a boring bar that may be capable of reducing a weight of the tool installed at a front end of the boring bar. also It is a further object of the invention to provide a method of exchanging a tool of a boring bar using the above-mentioned apparatus.

To this end, the present invention provides an apparatus in accordance with claim <NUM> and a method in accordance with claim <NUM>.

According to the present invention, there is provided an apparatus for exchanging a tool of a boring bar. The apparatus includes a magazine, a frame, a guide rail and an actuator. The magazine is configured to receive a plurality of the tools. The frame is arranged under the magazine. The guide is arranged on the frame. The magazine is movably connected to the guide rail. The actuator is configured to rotate the magazine.

In example embodiments, the magazine may include a rotation plate rotated by the actuator and a plurality of holders arranged on an outer surface of the rotation plate to hold the tools.

In example embodiments, the magazine may be rotated with respect to an axial direction of the boring bar.

In example embodiments, the guide rail may be extended in a direction substantially perpendicular to a rotation shaft of the magazine.

In example embodiments, the apparatus may further include a cylinder arranged at the frame to move the magazine along the guide rail.

In example embodiments, the apparatus may further include a bracket movably connected to the guide rail. The magazine may be rotatably connected to the bracket. The actuator may be installed at the bracket.

In example embodiments, the actuator may include a servo motor.

In example embodiments, the magazine may be arranged between a spindle exchanging apparatus and a spindle configured to fix a workpiece machined by the boring bar.

According to the invention, there is also provided a method of exchanging a tool of a boring bar. In the method of exchanging the tool of the boring bar, a magazine is arranged on an axial direction of a main shaft of the boring machine. A plurality of holder configured to hold a plurality of the tools are installed at the magazine. The magazine is rotated to locate a holder holding a new tool at an exchange position. The boring with the tool is arranged at a front of the boring bar. The tool is exchanged for the new tool.

In example embodiments, arranging the magazine on the axial direction of the main shaft may include horizontally moving the magazine along a guide rail.

In example embodiments, the method may further include returning the magazine to an original position after exchanging the tool for the new tool.

According to the invention, the magazine configured to hold the tools may be arranged between the main shaft and the spindle exchanging apparatus to reduce a weight of the tool. Thus, a damper may have a vibration damping capacity to decrease an impulse generated in exchanging the tool. Further, the tool may be exchanged for the new tool regardless of a size of a workpiece.

Various example embodiments will be described more fully hereinafter with reference to the accompanying drawings, in which some example embodiments are shown.

The present invention may, however, be embodied in many different forms and should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity.

It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention.

<FIG> is a perspective view illustrating a boring machine with a tool exchanging apparatus.

Referring to <FIG>, a boring machine may include a main shaft <NUM>, a vibration isolator <NUM>, a spindle <NUM>, a tail stock <NUM>, a transfer stock <NUM>, a spindle exchange apparatus <NUM>, a boring bar storage apparatus <NUM> and a tool exchange apparatus <NUM>.

The main shaft <NUM> may be horizontally arranged to fix a one end of a workpiece W. The workpiece W may have a long pipe shape having a hole. The vibration isolator <NUM> may support the other end of the workpiece W to prevent a vibration of the workpiece W.

The spindle <NUM> may be transferred by the transfer stock <NUM>. The transfer stock <NUM> may transfer the spindle <NUM> in horizontal and vertical directions. A boring bar B may be fixed to a lower end of the transfer stock <NUM>. The boring bar B may machine an inner surface of the hole of the workpiece W. The boring bar B may have a bar shape having a long length. The tail stock <NUM> may support an end of the boring bar B fixed to the lower end of the transfer stock <NUM>.

The spindle exchange apparatus <NUM> may be arranged on an end of the main shaft <NUM>. The spindle exchange apparatus <NUM> may exchange the spindle <NUM> for a new spindle. The spindle exchange apparatus <NUM> may be arranged in a direction substantially parallel to an axial direction of the main shaft <NUM>.

The boring bar storage apparatus <NUM> may be arranged over the tail stock <NUM>. A door <NUM> may be arranged between the boring bar storage apparatus <NUM> and the spindle <NUM>. The boring bar storage apparatus <NUM> may store a plurality of new boring bars B. The boring bar storage apparatus <NUM> may forward to the transfer stock <NUM> to exchange the boring bar B fixed to the transfer stock <NUM> for the new boring bar B.

<FIG> is an enlarged perspective view illustrating the tool exchanging apparatus in <FIG>, <FIG> is a perspective view illustrating an operation of the tool exchanging apparatus in <FIG> and <FIG> is a front view illustrating the tool exchanging apparatus in <FIG>.

Referring to <FIG>, the tool exchange apparatus <NUM> is configured to exchange a tool T installed at a front end of the boring bar B for a new tool T. The tool exchange apparatus <NUM> may be arranged between the main shaft <NUM> and the spindle exchange apparatus <NUM>. The tool exchange apparatus <NUM> includes a frame <NUM>, a guide rail <NUM>, a bracket <NUM>, a cylinder <NUM>, a magazine <NUM> and an actuator <NUM>.

The frame <NUM> may be arranged between the main shaft <NUM> and the spindle exchange apparatus <NUM>. The frame <NUM> may be extended in a direction substantially perpendicular to the axial direction of the main shaft <NUM>. The guide rail <NUM> may be arranged on an upper surface of the frame <NUM>. The guide rail <NUM> may be extended in the direction substantially perpendicular to the axial direction of the main shaft <NUM>.

The bracket <NUM> may be movably connected to the guide rail <NUM>. The bracket <NUM> may include a slider <NUM> and a supporting plate <NUM>. The slider <NUM> may be movably connected to the guide rail <NUM>. The supporting plate <NUM> may be arranged on an upper surface of the slider <NUM>. The slider <NUM> may be moved along the guide rail <NUM> to move the bracket <NUM> along the direction substantially perpendicular to the axial direction of the main shaft <NUM>.

The cylinder <NUM> may be installed at the upper surface of the frame <NUM>. The cylinder <NUM> may provide the bracket <NUM>, particularly, the slider <NUM> with a straight movement force in the direction substantially perpendicular to the axial direction of the main shaft <NUM>. Thus, the slider <NUM> may be moved along the guide rail <NUM> by the straight movement force provided from the cylinder <NUM>.

The magazine <NUM> may be arranged on a first surface of the supporting plate <NUM> of the bracket <NUM>, i.e., a front surface of the supporting plate <NUM> oriented toward the spindle <NUM>. The magazine <NUM> may include a rotation plate <NUM> and a plurality of holder <NUM>. The rotation plate <NUM> may be rotatably connected to the supporting plate <NUM> with respect to the axial direction of the main shaft <NUM>. The holders <NUM> may be arranged on an outer surface of the rotation shaft <NUM>. The holders <NUM> may be configured to hole the tools T. A holder <NUM> with the tool T to be exchanged among the holders <NUM> may be positioned at an exchange position by the rotation of the rotation plate <NUM>.

The actuator <NUM> may be installed at a second surface of the supporting plate <NUM> opposite to the first surface. The actuator <NUM> may rotate the rotation shaft <NUM> of the magazine <NUM> with respect to the axial direction of the main shaft <NUM>. In example embodiments, the actuator <NUM> may include a servo motor.

<FIG> is a flow chart illustrating a method of exchanging a tool of a boring bar using the apparatus in <FIG>.

Referring to <FIG> and <FIG>, in step ST410, the tool T may be unclamped from the boring bar B. Particularly, the boring bar B with the tool T may be moved forwardly to the exchange position. The magazine <NUM> may be moved to hold the tool T. The boring bar B may then be moved backwardly to unclamp the tool T from the boring bar B.

In step ST420, the cylinder <NUM> may move forwardly the bracket <NUM> along the guide rail <NUM> to position the bracket <NUM> on the axial direction of the main shaft <NUM>.

In step ST430, the actuator <NUM> may rotate the magazine <NUM> to locate the holder <NUM> with the tool T to be exchanged at the exchange position.

In step ST440, the transfer stock <NUM> may be moved toward the magazine <NUM>. Thus, the spindle <NUM> may be moved to the front of the magazine <NUM> to locate the front end of the boring bar B at the front of the holder <NUM>.

In step ST450, the boring bar B may clamp the new tool T in the holder <NUM>. Particularly, the boring bar B may be moved forwardly to clamp the new tool T in the holder <NUM>. The magazine <NUM> may be moved to release the new tool T from the magazine <NUM>. Thus, the boring bar B may clamp the new tool T.

After exchanging the tool T, in step ST460, the cylinder <NUM> may move backwardly the bracket <NUM> along the guide rail <NUM> to return the bracket <NUM> at the original position. The transfer stock <NUM> may also be returned to an original position so that the spindle <NUM> and the boring bar B may be returned to a machining position.

According to the example embodiments, the magazine configured to hold the tools may be arranged between the main shaft and the spindle exchanging apparatus to reduce a weight of the tool. Thus, a damper may have a vibration damping capacity to decrease an impulse generated in exchanging the tool. Further, the tool may be exchanged for the new tool regardless of a size of a workpiece.

Claim 1:
An apparatus (<NUM>) for exchanging a tool (T) of a boring bar (B), the apparatus (<NUM>) comprising:
a magazine (<NUM>) configured to receive a plurality of the tools (T) to be installed at a front end of the boring bar (B);
a frame (<NUM>) arranged under the magazine (<NUM>);
a guide rail (<NUM>) arranged on the frame (<NUM>), the magazine (<NUM>) being movably connected to the guide rail (<NUM>); and
an actuator (<NUM>) configured to rotate the magazine (<NUM>).