Feeding device and machine tool using the same

A feeding device includes a tool holder, a cutter, a feeding mechanism and a mounting seat. The cutter is positioned on the tool holder. The mounting seat has at least one guiding portion. The tool holder is engaged with the at least one guiding portion. The feeding mechanism drives the tool holder and the cutter to controllably reciprocate along the at least one gliding portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims all benefits accruing under 35 U.S.C. §119 from China Patent Application No. 201210252850.1, filed on Jul. 20, 2012, in the China Intellectual Property Office, the disclosure of which is incorporated herein by reference. The application is also related to co-pending applications entitled, “MACHINE TOOL WITH UNINTERRUPTED CUTTING” Ser. No. 13/705843; “FEEDING DEVICE AND MACHINE TOOL USING THE SAME” Ser. No. 13/705788; “METHOD FOR MACHINING CURVED SURFACE USING LATHE” Ser. No. 13/705777; “LATHE FOR MACHINING CURVED SURFACES” Ser. No. 13/705713; “LATHE WITH TWO CROSS BEAMS” Ser. No. 13/705585; “LATHE CONTROL SYSTEM” Ser. No. 13/705545; “WORKPIECE HAVING NON-ROTARY SURFACE MACHINED BY LATHE” Ser. No. 13/705478; “LATHE FOR MACHINING CURVED SURFACES” Ser. No. 13/705383.

BACKGROUND

1. Technical Field

The present disclosure generally relates to feeding devices, and particularly, to a feeding device which can machine a curved surface, and a machine tool using the same.

2. Description of the Related Art

In the manufacturing field, a cutter of the machine tool is driven to move by a feeding device of the machine tool, and also driven to rotate in high speed by a main shaft of the machine tool at the same time for machining a curved surface of a workpiece. However, after completing machining a first position of the workpiece, the feeding device needs to be driven to lift and move a certain distance to a second position of the workpiece by the main shaft. This consumes more time, and the machining efficiency is decreased.

Therefore, there is room for improvement within the art.

DETAILED DESCRIPTION

Referring toFIGS. 1 and 2, an embodiment of a machine tool100is shown. The machine tool100is used for machining a curved surface at a workpiece200. The machine tool100includes a machine support10, a work table20, a moving device30, a feeding device40, and a controller (not shown). The work table20holds the workpiece200and is supported by the machine support10. The moving device30is movably positioned on the machine support10above the work table20. The feeding device40is slidably mounted on the moving device30. The controller is electrically connected with the work table20, the moving device30, and the feeding device40for controlling the machine tool100. Under the control of the controller, the moving device30can be driven to move with the feeding device40, such that the feeding device40can be driven to move along X, Y, and Z axes.

The machine support10includes a base11and a pair of support bodies13positioned parallel on the base11. A pair of first sliding rails131are positioned parallel on a surface of each support body13away from the base11, and arranged apart from each other. In the illustrated embodiment, the first sliding rails131extend parallel to the X-axis. A receiving groove133is formed on each support body13between the two first sliding rails131.

Referring also toFIG. 2, the work table20is substantially cylindrical, and rotatably positioned on the base11between the two support bodies13. The work table20includes a rotating driver21and a support member23fixedly connected with the rotating driver21away from the base11. The rotating driver21is electrically connected with the controller. In the illustrated embodiment, the rotating driver21is a direct drive motor.

The moving device30is slidably perpendicularly mounted on the pair of support bodies13above the work table20. The moving device30includes a cross beam31, two sliding bases33, two first driving mechanisms35, and a second driving mechanism37. Two ends of the cross beam31are slidably positioned on the support bodies13via the pair of sliding bases33, respectively. The extending direction of the cross beam31is parallel to the Y-axis. The pair of second sliding rails311are positioned on a side surface of the cross beam31adjacent to the work table20and extending parallel to the Y-axis. The two sliding bases33are installed on the opposite ends of the cross beam31to slidably connect with the first sliding rails131. Each first driving mechanism35is mounted on a surface of one sliding base33away from the cross beam31and received in the receiving groove133. The first driving mechanisms35are configured for driving the cross beam31to move along the first sliding rails131. The second driving mechanism37is mounted on the cross beam31to drive the feeding device40to move along the second sliding rails311. The first driving mechanisms35and the second driving mechanism37are electrically connected with the controller. In the illustrated embodiment, the first driving mechanisms35and the second driving mechanism37are linear motors. In other embodiments, the first driving mechanisms35and the second driving mechanism37may be replaced by other drivers, such as the cylinders. The number of the first driving mechanisms35and the second driving mechanism37may be designed according to their applications.

Also referring toFIGS. 3 to 5, the feeding device40includes a mounting seat43, a tool holder45, two feeding mechanisms47, and a cutting tool49. The feeding mechanisms47are mounted and received in the mounting seat43, and electrically connected with the controller. The tool holder45is slidably positioned on the mounting seat43, and driven to undergo a reciprocating motion parallel to the Z-axis relative to the mounting seat43.

In the illustrated embodiment, referring again toFIG. 2, the feeding device40further includes a sliding saddle41. The sliding saddle41is movably positioned on the mounting seat43, and movably assembled with the cross beam31. Two sliding blocks411are separately positioned on a surface of the sliding saddle41away from the tool holder45, and parallel to the Y-axis toward the cross beam31. The sliding blocks411are slidably engaged with the second sliding rails311correspondingly.

The mounting seat43includes a frame431, and two mounting boards433. The frame431includes a bottom wall4311, a first side wall4313, a second side wall4315, and a top wall4316. The first side wall4313and the second side wall4315extend perpendicularly from two ends of the bottom wall4311to connect with the top wall4316, such that the bottom wall4311, the first side wall4313, the second side wall4315, and the top wall4316cooperatively define a receiving space4310. The bottom wall4311is positioned adjacent to the base11. The first side wall4313is slidably connected with the sliding saddle41. Two guiding portions4317protrude from an inner surface of the first side wall4313facing toward the second side wall4315and extend parallel to the Z-axis. A through groove4318is defined in the second side wall4315and extends along a direction parallel to the Z-axis. Two guiding portions4319protrude from an outer surface of the second side wall4315at two sides of the through groove4318. In the illustrated embodiment, the guiding portions4319are sliding rails, and the frame431is integrally formed. Two mounting boards433are respectively installed on two opening sides of the frame431. Each mounting board433is perpendicularly connected with the bottom wall4311, the first side wall4313, the second side wall4315, and the top wall4316for closing the frame431.

The tool holder45slidably connects with the mounting seat43. The tool holder45is substantially “T” shaped, and includes a main body451and a sliding board453substantially perpendicularly protruding from the main body451. The main body451is a bar of material tapering in at both ends and positioned outside of the mounting seat43. Two holding portions4511are positioned on a bottom of the main body451away from the sliding board453. Four first direct portions4513(seeFIG. 5) are positioned on a surface of the main body451adjacent to the sliding board453. The four first direct portions4513are divided into two groups, each group having two gliding portions4513slidably engaged with one guiding portion4319. The sliding board453is located between the two groups of the first direct portions4513. The sliding board453passes through the through groove4318and is slidably attached to the two guiding portions4317. A second direct portion4531is formed on an end of the sliding board453away from the main body451, and received in the guiding portion4317. In the illustrated embodiments, the first direct portions4513are sliding blocks, and the second direct portion4531is a sliding rail.

The feeding mechanism47is mounted in the mounting seat43, and includes two drivers471. In the illustrated embodiment, the drivers471are linear motors. Each driver471includes a forcer4711and a stator4713. Each forcer4711is fixed to a surface of the corresponding mounting board433facing the receiving space4310, and is received in the receiving space4310. The sliding board453is positioned between the two forces4711. The forcers4711produce alternating magnetic fields when the forcers4711are electrically connected with an alternating current. Two stators4713are respectively fixedly positioned on the opposite surfaces of the sliding board453. Each stator4713is located between one forcer4711and the sliding board453. Interactions between magnetic fields produced by the stators4713and the alternating magnetic fields which are produced by the forcers4711drive the tool holder45to move in a reciprocating motion at high speed along the direction of the Z-axis. In other embodiments, the number of drivers471may be designed according to the real application. For example, the two drivers471can be take the place of a driver with more driving force, or three or more drivers can be positioned to drive the tool holder45to maximize energy, and assembly of the drivers can be made easy.

The cutter49is fixedly clamped between the two holding portions4511for machining curved surfaces of the workpiece200. The cutter49includes a shank491and a cutter body493connected with the shank491. The shank491is fixedly located between the two holding portions4511. The cutters body493is positioned adjacent to the base11. In the illustrated embodiment, the cutter49is a lathe tool.

In other embodiments, the mounting seat43may be fixedly positioned on the sliding saddle41when the machine tool100machines the workpieces200of one type. In other words, the mounting seat43does not need to move along the Z-axis direction. A driving mechanism electrically connected with the controller may be positioned in the feeding device40to drive the mounting seat43to slide along the sliding saddle41in the Z-axis. The sliding saddle41may be omitted, and the mounting seat43can be directly slidably positioned on the cross beam31.

In other embodiments, the forcers4711may be directly installed on the frame431. The alternating magnetic fields produced by the forcers4711drive the stators4713, thereby causing the tool holder45to undergo a reciprocating motion at high speed along the guiding portions4317.

In assembly, the work table20is positioned between the two support bodies13. The cross beam31is installed on the two support bodies13. The first driving mechanism35and the second mechanism37are mounted on the cross beam31. The sliding saddle41is also correspondingly positioned on the cross beam31. The two stators4713are fixedly mounted on two surfaces of the sliding board453, respectively. The sliding board453passes through the through groove4318and slidably connected with the second direct portion4531. Each forcer4711is installed on one mounting board433and received in the mounting seat43together with the mounting board433. The cutter49is fixedly mounted between the two holding portions4511. Finally, the feeding device40is positioned on the sliding saddle41and electrically connected with the controller.

In use, the workpiece200is placed on the work table20. The first driving mechanism35drives the moving device30to move along the first sliding rails131in the X-axis direction, the driving mechanism37drives the moving device30to move along the second sliding rails in the Y-axis direction, and the mounting seat43slides back and forth on the sliding saddle41in the Z-axis direction under the control of the controller. The feeding device40arrives at a preset position for machining. The first driving mechanism35drives the moving device30to move along the first sliding rails131in the X-axis direction, the rotating driver21drives the workpiece to rotate, and the cutter49is driven to reciprocate at high speed in the Z-axis direction by the drivers471for machining the workpiece200at the same time. The rotating speed of the rotating driver21, and the speed and the amplitude of the cutter49are programmed according to cutting removal of each machining portion of the workpiece200. The planar machining path of the cutter49is substantially spiral. The feeding device40and the work table20stop moving, and the moving device30returns to its initial position after completing machining. The workpiece200can then be unloaded from the work table20.

The interaction between the alternating magnetic fields produced by the forcers4711and the magnetic fields produced by the stators4713, will drive the tool holder45and the cutter49to reciprocate at high speed along the guiding portion4317in the Z-axis for curved surface machining the workpiece200. The feeding device40machines the workpiece200all the time depending on its motions at high speed in the Z-axis. There is no need to move the feeding device40during machining. Much time will be saved compared with the traditional feeding device, and the maximum machining efficiency will be achieved. Traditionally, a milling cutter with different cutting edges is used for machining curved surfaces. Some trace will retain on the milling surface of the workpiece because of discontinuous milling of the milling cutter. A polishing process would need to be performed on the workpiece. However, no other process needs to be added to the workpiece200used by the machine tool100because the cutter49is continuously machining.

While the present disclosure has been described with reference to particular embodiments, the description is illustrative of the disclosure and is not to be construed as limiting the disclosure. Therefore, various modifications can be made to the embodiments by those of ordinary skill in the art without departing from the true spirit and scope of the disclosure, as defined by the appended claims.