Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B31/00—Chucks; Expansion mandrels; Adaptations thereof for remote control
  • B23B31/02—Chucks
  • B23B31/24—Chucks characterised by features relating primarily to remote control of the gripping means
  • B23B31/30—Chucks characterised by features relating primarily to remote control of the gripping means using fluid-pressure means in the chuck
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B31/00—Chucks; Expansion mandrels; Adaptations thereof for remote control
  • B23B31/02—Chucks
  • B23B31/10—Chucks characterised by the retaining or gripping devices or their immediate operating means
  • B23B31/12—Chucks with simultaneously-acting jaws, whether or not also individually adjustable
  • B23B31/16—Chucks with simultaneously-acting jaws, whether or not also individually adjustable moving radially
  • B23B31/16287—Chucks with simultaneously-acting jaws, whether or not also individually adjustable moving radially using fluid-pressure means to actuate the gripping means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B31/00—Chucks; Expansion mandrels; Adaptations thereof for remote control
  • B23B31/02—Chucks
  • B23B31/10—Chucks characterised by the retaining or gripping devices or their immediate operating means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B31/00—Chucks; Expansion mandrels; Adaptations thereof for remote control
  • B23B31/02—Chucks
  • B23B31/10—Chucks characterised by the retaining or gripping devices or their immediate operating means
  • B23B31/12—Chucks with simultaneously-acting jaws, whether or not also individually adjustable
  • B23B31/16—Chucks with simultaneously-acting jaws, whether or not also individually adjustable moving radially
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B2270/00—Details of turning, boring or drilling machines, processes or tools not otherwise provided for
  • B23B2270/12—Centering of two components relative to one another

Definitions

• the present invention relates to a clamping chuck for a machine tool, and more particularly, to a synchronized clamping chuck for a machine tool for chucking a work piece such that a center of the work piece coincident with a center of a chuck housing exactly with jaws moving by means of a hydraulic pressure of hydraulic oil filled in the chuck housing.
• a scroll chuck is used, whereby jaws move in a direction for clamping/releasing the work piece following rotation of a scroll rotated by a lever.
• the scroll chuck is provided with the scroll and the jaws in the chuck housing and a chuck cover such that, if a gear lever is rotated, a bevel gear rotates to rotate a crown gear on the scroll together with the scroll, to move a plurality of the jaws engaged with the scroll toward a center of the chuck housing or opposite thereto depending on a rotation direction of the scroll.
• the scroll chuck has problems in that the manual rotation of the gear lever every time the worker clamps/releases the clamp the work piece with jaws is not convenient and impairs work efficiency, and the low clamping power of the manual rotation can not sustain an accurate machining, and causes cases when the work piece falls off the jaws in the middle of machining.
• the hydraulic chuck is provided with wedge plungers therein having guide holes sloped at predetermined angles each with a jaw engaged therein, for moving the wedge plungers back and forth with the hydraulic cylinders to move the jaws along the guide holes so that the jaws clamp or release the clamping of the work piece.
• the related art hydraulic chuck has problems in that a high cost is required due to a hydraulic unit having a direction change valve, a hydraulic pump, and a holding tank which requires supply of a hydraulic pressure for moving the hydraulic cylinder which moves the wedge plungers back and forth, and accurate machining of circular work piece is difficult due to difficulty in clamping the circular work piece with centers of the work piece and the chuck coincident, accurately.
• the multi-hydraulic chuck for a machine tool filed by the applicant having a structure in which the hydraulic oil pressurizing means applies a pressure to the hydraulic oil held in the chuck housing to increase a hydraulic pressure, has a problem in that the hydraulic pressure increased by the hydraulic oil pressurizing means is transmitted to a jaw closest to the hydraulic oil pressurizing means at first, and then is transmitted to jaws gradually proportional to distances from the means.
• An object of the present invention devised to solve the problem lies on providing a synchronized clamping chuck for a machine tool, in which a plurality of jaw move at the same time to clamp a work piece with a hydraulic pressure increased by hydraulic oil pressurizing means so that a center of the work piece is positioned at a center of the chuck, and then other jaw clamp the work piece, so that accurate machining can be made in a state the work piece is clamped rigidly in a state the centers of the work piece and the chuck are coincident, the error can be minimized.
• the synchronized clamping chuck for a machine tool including a chuck housing having a body with a work piece hole, a main hydraulic chamber filled with hydraulic oil, and a first working hydraulic oil chamber and a plurality of second hydraulic oil chambers, both of which are formed in a radial direction toward the work piece hole and in com- munication with the main hydraulic oil chamber, hydraulic oil pressurizing means mounted to the main hydraulic oil chamber for applying a pressure to the hydraulic oil in the main hydraulic oil chamber to increase a hydraulic oil pressure of the working hydraulic oil chambers, a main jaw mounted to the chuck housing and coupled to the first working hydraulic oil chamber in the chuck housing for moving toward a center of the work piece hole, synchronized jaws mounted to the chuck housing and coupled to the second working hydraulic oil chambers for moving toward a center of the work piece hole in synchronization with the main jaw, a plurality of working jaws mounted to the
• FlG. 1 illustrates a front view of a synchronized clamping chuck in accordance with a preferred embodiment of the present invention
• FlG. 2 illustrates a section across a line A-A'in FlG. 1 ;
• FlG. 3 illustrates a section across a line B-B'in FlG. 2;
• FlG. 4 illustrates a back view of a synchronized clamping chuck in accordance with a preferred embodiment of the present invention.
• FlG. 1 illustrates a front view of a synchronized clamping chuck in accordance with a preferred embodiment of the present invention.
• the synchronized clamping chuck includes a chuck housing having jaw guide grooves formed in a front surface in a radial direction toward a work piece hole, and a main jaw, synchronized jaws, and working jaws movably mounted in the jaw guide grooves, respectively.
• FlG. 2 illustrates a section across a line A-A' in FlG. 1, showing hydraulic oil pressurizing means, main jaw moving means, and working jaw moving means.
• FlG. 3 illustrates a section across a line B-B' in FlG. 2, comparing synchronized jaw moving means connected to main moving means with synchronized moving connection means to working jaw moving means which is not connected to the main moving means.
• FlG. 4 illustrates a back view of a synchronized clamping chuck in accordance with a preferred embodiment of the present invention, showing a state the synchronized jaw moving means is connected to the main jaw moving means with the synchronized moving connection means at a back side of the synchronized clamping chuck.
• the chuck housing 10 of the present invention has a circular body with a work piece hole 11 at a center for placing the work piece therein, and jaw guide grooves 15 in a front surface formed in a radial direction toward the work piece hole 11 in each of which the main jaw 30 or the working jaw 50 is movably mounted as described later.
• the jaw guide groove 15 having the main jaw 30 or the working jaw 50 placed therein serves to guide movement of the main jaw 30 or the working jaw 50 toward the center of the work piece hole 11.
• the chuck housing 10 has a main hydraulic oil chamber 12 therein opened to an outside of the chuck housing 10 filled with hydraulic oil.
• the chuck housing 10 also has a first working hydraulic oil chamber 13 formed toward the center of the work piece hole 11 in communication with the main hydraulic oil chamber 12, and second working hydraulic oil chambers 14 formed in a radial direction toward the center of the work piece hole 11 at regular intervals in communication with the first working hydraulic oil chamber 13.
• the first and second working hydraulic oil chambers 13 and 14 are formed in the chuck housing 10 with a number and positions corresponding to the jaw guide grooves 15 in the chuck housing 10.
• the main hydraulic oil chamber 12 has hydraulic oil pressurizing means 20 mounted thereto for applying a pressure to the hydraulic oil in the main hydraulic oil chamber 12, wherein the hydraulic oil pressurizing means 20 includes a moving up/ down bolt 21 having a continuous thread on an outside circumference engaged to the chuck housing 10 to turn with a tool and an end positioned in the main hydraulic oil chamber 12, and a master piston 22 at the end of the moving up/down bolt 21 having an outside circumferential surface in close contact with an inside wall of the main hydraulic oil chamber 12 for applying a pressure thereto with the hydraulic oil.
• the hydraulic oil pressurizing means 20 includes a moving up/ down bolt 21 having a continuous thread on an outside circumference engaged to the chuck housing 10 to turn with a tool and an end positioned in the main hydraulic oil chamber 12, and a master piston 22 at the end of the moving up/down bolt 21 having an outside circumferential surface in close contact with an inside wall of the main hydraulic oil chamber 12 for applying a pressure thereto with the hydraulic oil.
• the moving up/down bolt 21 has a hexagonal hole 21a in a top for rotating with a hexagonal wrench.
• the increased hydraulic pressure is transmitted to the first working hydraulic oil chamber 13 directly in communication with the main hydraulic oil chamber 12, and therethrough to the second working hydraulic oil chamber 14.
• the working jaws 50 in the jaw guide grooves 15 of the chuck housing 10 are coupled to the second working hydraulic oil chambers 14 respectively and synchronizing jaws 40 are coupled to at least one of the second working hydraulic oil chamber 14.
• the synchronizing jaws 40 are coupled to the two second working hydraulic oil chambers 14 spaced 120 degrees away from the main jaw moving means 60.
• Each of the main jaw 30, the synchronizing jaws 40, and the working jaws 50 has a movable guide hole 100 having an inwardly sloped surface in a back surface thereof.
• the sloped surface of the movable guide hole 100 has an angle opposite to each of movable projections 110 from main jaw moving bar 63 and working jaw moving bars 83 respectively to be described later placed therein such that the movable projections 110 move along the sloped surfaces of the movable guide holes 100 of the main jaw 30, the synchronizing jaws 40, and the working jaws 50, respectively.
• Each of the main jaw 30, the synchronizing jaws 40, and the working jaws 50 includes a master jaw 30a having the movable guide hole 100 in a back surface sloped inwardly from an outside surface, and a soft jaw 30b fixedly secured to a front surface of the master jaw 30a having one end projected toward the work piece hole 11 in the chuck housing 10 for clamping the work piece.
• a main jaw 13 for moving the main jaw 30 and includes a cover plate 61 on a back side of the chuck housing 10 for closing the first working hydraulic oil chamber 13, a main piston 62 having a body in close contact to an inside surface of the first working hydraulic oil chamber 13 for moving along an inside wall of the first working hydraulic oil chamber 13 with a first projection 62a projected to the back side of the chuck housing 10 through the cover plate 61 and connected to connection means, and the hydraulic oil of the working hydraulic oil chamber 13 filled in front, a main jaw moving bar 63 in front of the main piston 62 passed through the first working hydraulic oil chamber 13 and projected to a front surface of the chuck housing 10, having an end provided with the movable projection 110 sloped toward the center of the work piece hole 11, and a main piston return spring 64 between the main piston 62 and the cover plate 61 for supporting the main piston 62, elastically.
• first, and second sealing rings 62b, and 63a for preventing the hydraulic oil from leaking from the first working hydraulic oil chamber 13, respectively.
• the synchronized jaw moving means 70 includes the cover plate 61 on the back side of the chuck housing 10 for closing the second working hydraulic oil chamber 14, a synchronized piston 72 having a body in close contact to an inside surface of the second working hydraulic oil chamber 14 for moving along an inside wall of the second working hydraulic oil chamber 14 with a second projection 72a projected to the back side of the chuck housing 10 through the cover plate 61 and connected to the connection means, and the hydraulic oil of the working hydraulic oil chamber 14 filled in front, a synchronized jaw moving bar 73 in front of the synchronized piston 72 passed through the second working hydraulic oil chamber 14 and projected to the front surface of the chuck housing 10, having an end provided with the movable projection 110 sloped toward the center of the work piece hole 11, and a synchronized piston return spring 74 between the synchronized piston 72 and the cover plate 61 for supporting the synchronized piston 72, elastically.
• the working jaw moving means 80 for moving the working jaw 50, wherein the working jaw moving means 80 includes the cover plate 61 at the back side of the chuck housing 10 for closing the working hydraulic oil chamber, a working piston 82 having a body in close contact to an inside surface of the second working hydraulic oil chamber 14 for moving along an inside wall of the second working hydraulic oil chamber 14, and the hydraulic oil filled from the main hydraulic oil chamber 12 in a front, a working jaw moving bar 83 in front of the working piston 82 passed through the working hydraulic oil chamber and projected to the front surface of the chuck housing 10, having an end provided with the movable projection 110 sloped toward the center of the work piece hole 11, and a working piston return spring 84 between the working piston 82 and the cover plate 61 for supporting the working piston 82, elastically.
• each of the working piston 82 and the working jaw moving bars 83 there are fifth, and sixth sealing rings 82a, and 83a for preventing the hydraulic oil from leaking from the second working hydraulic oil chamber 14, respectively.
• the synchronized moving connection means 90 includes a connection plate 91 at the back side of the chuck housing 10 fastened to the synchronized jaw moving means 70 which is connected to the main jaw moving means 60 with bolts 92.
• the hydraulic oil is filled in the main hydraulic oil chamber 12 in the chuck housing
• the working jaws 50 clamp the work piece with slight differences after the main jaw 30 and the synchronized jaw 40 clamp the work piece at a time to position at the center of the work piece hole 11 such that the centers of the work piece and the work piece hole 11 are coincident owing to the main piston 62 and the synchronized pistons 72 connected to, and moving with the main piston 62 by the increased hydraulic pressure from the main hydraulic oil chamber 12, the synchronized clamping chuck of the present invention can clamp the work piece rigidly such that the centers of the work piece and the work piece hole 11 are coincident.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Gripping On Spindles (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=37621106

Family Applications (1)

Country Status (5)

Cited By (2)

Families Citing this family (10)

Citations (3)

Family Cites Families (4)

• 2005
  • 2005-09-23 KR KR1020050088533A patent/KR100639412B1/ko active IP Right Grant
• 2006
  • 2006-09-20 EP EP06798817A patent/EP1928625A1/en not_active Withdrawn
  • 2006-09-20 JP JP2008532160A patent/JP2009508705A/ja not_active Ceased
  • 2006-09-20 WO PCT/KR2006/003734 patent/WO2007035037A1/en active Application Filing
  • 2006-09-20 CN CN2006800350314A patent/CN101272878B/zh not_active Expired - Fee Related

Patent Citations (3)

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