This invention relates to a pallet changing system which changes a pallet that supports a workpiece at an operating leading-end portion of a machine head and gripped by a pallet clamping device with a pallet for changing which is placed at a set-up station to support the other workpiece.
The pallet clamping device arranges the workpiece at a leading-end operating position of the machine head via the gripped pallet, and the pallet for changing is arranged at the set-up station.
In conventional techniques, in the case of changing a pallet with the pallet clamping device, an external device is used to convey the pallet between the clamping device and the set-up station.
Further, conveyance of the pallet is with no relation whether the pallet clamping device is a movable type or a fixed type.
In typical system, the pallet is conveyed by a pallet changing arm device capable of expanding and reducing an arm in a multiple stage or a pallet changing arm device capable of moving in itself.
However, since the pallet changing arm device capable of expanding and reducing the arm needs a larger installation space and the device only changes a pallet one by one, it inevitably needs a longer time to change a pallet.
On the other hand, the movable-type pallet changing arm device inevitably needs a control device for moving and stopping the arm, and the control device inevitably requires a more complicated configuration than the pallet changing arm device capable of expanding and reducing the arm.
In Patent Document 1 in which the patent right was obtained by applicant, attention is taken to the fact that a spindle which moves at the leading-end portion of the machine head is able to move freely, and so a pallet for machining is gripped by a spindle head on one side of a pallet changing arm (a pallet gripping arm), whereas a pallet for changing is gripped on the other side thereof. Thereby, when the spindle head descends, the pallet changing arm is allowed to ascend and, thereafter, the pallet changing arm is rotated, by which the pallets are changed efficiently.
In the above-described configuration, the pallet changing arm also acts as the pallet clamping device, and so, an ascending mechanism necessary for changing a pallet is relatively simple.
However, the above-described pallet changing arm needs an external driving device for moving the pallet changing arm and is placed over an operating position of the spindle head and the set-up station. So, above-described configuration inevitably needs a long and large space resultingly.
In Patent Document 2, a shoulder rail is provided on a pallet changing arm which can turn, and a pallet for changing is allowed to move on the rail. In above-described configuration, a mechanism of expanding and reducing the pallet changing arm or a mechanism of moving the pallet changing arm is unnecessary, and so may improve the conventional techniques.
However, the above-described configuration inevitably needs such another special control that in the case of pallet for changing being moved from an end portion side of the pallet changing arm to the center side of turning, the other pallet for supporting a workpiece which has been already machined by another operation is ascended and, contrary in the case of the other pallet being moved from the center position of the turning of the pallet changing arm to the end portion side thereof, the pallet for changing is descended.
In Patent Document 3, the leading end sides of intermediate portions on both sides of the pallet changing arm are supported pivotally at an upper perpendicular region so as to rotate freely and the leading end sides may be kept in upper position along perpendicular direction, with a certain angle according to the horizontal direction. Thereby, the pallet clamping device is compact in space and a pallet gripped by the pallet clamping device is changed by a simple configuration to improve the conventional techniques.
However, in the configuration disclosed in the above-described Patent Document 3, it is inevitably necessary to control the rotation of the arm on one side which takes out the pallet gripped by the pallet clamping device. And, such a mechanism invites another complex procedure which is different from in the conventional techniques.
Considering above-described conventional techniques and publicly known techniques such as Patent Documents 1, 2, and 3, it is apparent that pallet changing system which utilizes the moving function itself of the machine head for conveying a pallet has not been proposed, though the machine head of operating the spindle is capable of movement.
[Patent Document 1] Japanese Published Unexamined Patent Application No. 2005-81528
[Patent Document 2] Japanese Published Unexamined Patent Application No. 2000-176782
[Patent Document 3] Japanese Published Unexamined Patent Application No. 2000-24867
An object of the present invention is to provide a configuration of pallet changing system which utilizes the moving function itself of a machine head at a machining center for conveying a pallet and a configuration of a machining center equipping the system.
In order to attain the above object, the present invention is basically configured as follows:
(1) a pallet changing system which changes a pallet supporting a workpiece at an operating leading-end portion of a machine head and also gripped by a pallet clamping device with an another pallet for changing, placed at a set-up station and supporting the other workpiece,
comprising that a pallet changing unit equipping a rotational pillar rotating integrally with a pallet changing arm and a motor for driving the rotational pillar is installed such as capable of the state combined with the machine head and the state detached from the machine head and control unit is provided for controlling the machine head and the pallet changing unit according to each following processes:
I. a process of operating the machine head and fixing the pallet changing unit which holds a pallet for changing at a standing-by position;
II. a process of moving the machine head which has completed a predetermined unit of operation to said standing-by position and combining the machine head with the pallet changing unit after the movement;
III. a process of moving the machine head which is combined with the pallet changing unit to the side of the pallet clamping device, fitting an arm on one side not holding a pallet for changing, of arms on both sides of the pallet changing arm, into a pallet gripped by the pallet clamping device after the above movement, and attaining the state of pallet apart from the arm which has been gripping the pallet;
IV. a process of turning the pallet changing arm;
V. a process of changing a pallet for changing with a pallet gripped by the pallet clamping device;
VI. a process of returning the machine head which is combined with the pallet changing unit to said standing-by position and detaching the machine head from the pallet changing unit after the above returning; and
(2) a machining center which equips the above-described (1) of the pallet changing system and also machines a workpiece by using the machine head.
In the above-described basic configurations (1) and (2), it is fundamental feature that the pallet changing unit 1 may be combined with the machine head 2 and may move integrally with the machine head 2, and so, necessary control is undergone for conveying and changing a pallet 3.
In summing, as shown in
I. the process of operating the machine head 2 and keeping the pallet changing unit 1 at a stand-by position (
II. the process of moving the machine head 2 to said standing-by position and, thereafter, combining the machine head 2 with the pallet changing unit 1 (
III. the process of moving the machine head 2 combined with the pallet changing unit 1 to an operating position, thereafter, fitting the pallet changing arm 11 into the pallet 3, and gripping the pallet 3 (
IV. the process of turning the pallet changing arm 11 (
V. the process of changing the pallet 3 by the pallet changing arm 11 (
VI. the process of returning the machine head 2 combined with the pallet changing unit 1 to said sanding-by position (
As is shown in
Whether the pallet changing arm 11 can be turned at the process IV or not immediately after the pallet is held by the pallet changing arm 11 at the process III depends on whether a space available for the turning of the process IV exists or not in the vicinity of the pallet clamping device 4.
The case in which the above-described space is not available is described later in Embodiment 1 and Embodiment 2.
The flowchart given in
As shown in
The embodiment given in
Various configurations may be adopted as embodiments in which the pallet changing unit 1 is freely capable of the state engaged with the machine head 2 and the state detached from the machine head 2 is available in various configurations.
A configuration which can be selected most easily is that in which the machine head 2 is provided with a robot mechanism capable of gripping and disengaging from gripping of the pallet changing unit 1, thereby engaging the pallet changing unit 1 with the machine head 2 or detaching the pallet changing unit 1 therefrom.
However, regarding the robot mechanism, the robot mechanism in itself may be used to change the arm. And, it is not effective to use the robot mechanism in engaging the pallet changing unit 1 with the machine head 2 or detaching the pallet changing unit 1 therefrom.
Moreover, this invention adapts adopts a simple configuration, compared with conventional techniques in which the pallet changing arm 11 needs an expanding and reducing mechanism or a movable mechanism, adoption of the robot mechanism is not necessarily a preferred embodiment.
The above-described engagement and detachment of the pallet changing unit 1 is realized by an embodiment in which the convex portion 5 is provided at one of the pallet changing unit 1 and the machine head 2 and the recessed portion 6 is provided at the other of them, by which they are fitted with each other to attain engagement of the process II.
a) shows an embodiment in which a direction at which the convex portion 5 projects out and a direction at which the recessed portion 6 projects in intersect with the moving direction of the pallet changing unit 1 and the machine head 2, of the embodiments which adopt the recessed portion 6 and the convex portion 5.
In other words, the projecting-out and projecting-in directions of the convex portion 5 and the recessed portion 6 which are mutually fitted are selected as a direction intersecting with a direction at which the machine head 2 moves in a state of being engaged with the pallet changing unit 1. So, the pallet changing unit 1 and the machine head 2 can be prevented from a failure in a mutually fitted state, even in the case that a change in acceleration or an impact due to the above-described movement occurs, by fitting the convex portion 5 provided at one of them to the recessed portion 6 provided at the other of them.
In
In other words, as shown in
In
In other words, as shown in
Hereinafter, a description will be given in accordance with the embodiments.
As shown in
In other words, as shown in
As shown in
In other words, in Embodiment 2 as well, as shown in
The present invention based on the basic configurations (1), (2) eliminates a necessity for an expanding and reducing mechanism and a movable mechanism for conveyance of a pallet as needed in a conventional arm device, thus making it possible to save a space needed for expansion and reduction and a special control device needed for movement. So, it is possible to reduce production costs.
Further, since the machine head may move at high speeds, it is possible to reduce the time for conveyance of a pallet and also change the pallets efficiently.
Still further, as given in each of the embodiments described above, where the pallet changing unit and the machine head or the pallet clamping device is allowed to move to a predetermined position and the pallet changing arm is thereafter turned, it is also possible to change a pallet in a limited space.
The present invention is applicable to any pallet changing system and also to any machining center which has the pallet changing system and machines a workpiece by using a machine head. The present invention is in particular appropriate in changing a pallet at a small space in a short period of time.
Number | Date | Country | Kind |
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2011-180222 | Aug 2011 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
3659496 | Bergemann et al. | May 1972 | A |
3804426 | Mickas | Apr 1974 | A |
3968885 | Hassan et al. | Jul 1976 | A |
4013176 | Lohneis et al. | Mar 1977 | A |
4065988 | Lohneis et al. | Jan 1978 | A |
4399603 | Reed | Aug 1983 | A |
4457659 | Watanabe | Jul 1984 | A |
4844678 | Schenk | Jul 1989 | A |
5065499 | Luciano et al. | Nov 1991 | A |
5213559 | Lunazzi | May 1993 | A |
5240235 | Santandrea et al. | Aug 1993 | A |
5265497 | Curless | Nov 1993 | A |
6135696 | Haninger et al. | Oct 2000 | A |
6205631 | Schweizer | Mar 2001 | B1 |
6409641 | Hashimoto | Jun 2002 | B1 |
6436021 | Nukui | Aug 2002 | B2 |
6679369 | Okuyama | Jan 2004 | B2 |
6846276 | Yasumatsuya et al. | Jan 2005 | B2 |
7047706 | Kraenzle | May 2006 | B2 |
7478720 | Bernhard et al. | Jan 2009 | B2 |
RE40690 | Haninger et al. | Mar 2009 | E |
7621031 | Kawai et al. | Nov 2009 | B2 |
7694799 | Bae | Apr 2010 | B2 |
7909154 | Yoshida | Mar 2011 | B2 |
20060010681 | Bernhard et al. | Jan 2006 | A1 |
20060013675 | Bernhard et al. | Jan 2006 | A1 |
20080067035 | Keith et al. | Mar 2008 | A1 |
Number | Date | Country |
---|---|---|
2000-24867 | Jan 2000 | JP |
2000-176782 | Jun 2000 | JP |
2005-81528 | Mar 2005 | JP |
Number | Date | Country | |
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20130051958 A1 | Feb 2013 | US |