JP2005118942A - Work reversing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a work reversing device capable of reducing reversal use time, by reducing impact generated in starting and stopping even if a work is reversed at a high speed, when gripping and reversing the work by revolving, in a machine tool for machining both the obverse and reverse surfaces by reversing the work on the tool. <P>SOLUTION: This work reversing device comprises an arm revolvable around the revolving axis formed on a plane orthogonal to the main spindle axis, a revolving driving member for revolving and driving this arm by 180 degrees, a hand arranged on the tip of the arm and holding the work, and an arm expanding mechanism capable of approaching and separating this hand to the revolving axis. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a work reversing device for processing the front and back surfaces of a workpiece, and more specifically, in a machine tool having two parallel spindles, the workpiece is machined to sequentially process the front and back surfaces of the workpiece. It is related with the workpiece reversing device reversed by.

  For example, when machining the front and back of a workpiece on a lathe with one spindle, it is necessary to remove the workpiece once from the chuck, reverse it, and reattach it to the chuck after the front side machining is finished. During this time, processing is not performed, so it is not efficient. Therefore, a two-spindle lathe has been proposed to process a large number of workpieces. A processing machine with two spindles is constructed so that only the front side is machined with one spindle and only the back side is machined with the other spindle so that the machining stop time can be reduced as much as possible. FIG. 4 shows a two-spindle turning machine tool.

  In general, a machine tool for machining a workpiece in two steps is composed of a parallel two-spindle lathe 110, two reversing devices 111 and 112, a loader 113, a material stocker 114, and a product stocker 115 in FIG. The lathe 110 is provided with a first processing unit 116 that performs processing in the first step and a second processing unit 117 that performs processing in the second step.

However, in the conventional machine tool shown in FIG. 4, a case where the workpiece W processed by the first processing unit 116 is reversed by the reversing devices 111 and 112 will be described in the order of operation in FIG.
(1) The reversing device 111 grips the workpiece W,
(2) Turn 90 ° so that the reversing device 111 is directed from the direction parallel to the main axis indicated by the solid line to the reversing device 112 indicated by the broken line,
(3) Turn 90 ° so that the reversing device 112 faces the reversing device 111 indicated by the broken line from the direction parallel to the main axis indicated by the solid line,
(4) The reversing device 112 moves forward to the reversing device 117 side,
(5) The reversing device 112 grips the workpiece W,
(6) The reversing device 111 releases the workpiece W,
(7) The reversing device 111 moves backward to the first processing unit 116 side,
(8) The reversing device 112 turns 90 ° from the reversing device 111 direction indicated by the broken line so as to be parallel to the main axis indicated by the solid line,
(9) The reversing device 112 releases the workpiece W.
9 motions are required.

FIG. 6 shows another work reversing device provided with a work reversing device having a swivel arm in the middle between two machining portions. In FIG. 6, the turning radius of the work reversing device 13 is fixed to half the distance between the spindles. [Figure numbers are used as they are]
(For example, see Patent Document 1)

FIG. 7 and FIG. 8 show another work reversing device provided with a work reversing device in which a work gripping part turns in the middle between two processing parts.
In FIG. 7, two spindle chucks 3 and 4 for processing the front and back of the workpiece, the workpiece reversing device 10, the gantry loader 30, and the loader head 35 are shown. The movement of the workpiece W from the main shaft 3 to the main shaft 4 via the reversing device 10 is driven by a three-axis controlled gantry loader, and a loader head 35 with a chuck delivers the workpiece W to invert the workpiece. [Figure numbers are used as they are] (for example, see Patent Document 2)
Japanese Utility Model Publication No. 61-75901 FIG. 2, (corresponding to FIG. 6 of the present application) Japanese Utility Model Publication No. 4-118905 FIG. 1 (corresponding to FIG. 8 of the present application), FIG. 2 (corresponding to FIG. 7 of the present application)

  As described in the prior art, when two 90-degree swiveling devices are provided for two machining parts, the work is moved to the second chuck after the work is gripped by the chuck of the work swiveling device. 9 motions are required before the workpiece can be taken out from the second chuck by reversing, and it takes time to reverse the workpiece, and the cost is high because two 90-degree swiveling devices are required. There was a point.

In addition, when the length of the revolving arm for reversing the work is set to half the distance between the spindles, the power required for revolving is increased if the work shape is large and heavy, and the mechanical rigidity is enhanced. There was a problem that had to be done.
In addition, when a single work reversing device having a turning chuck that grips a work in the middle between the two processing parts and turns it at that position, swinging a heavy work can be avoided. However, when the workpiece is transferred between the spindle and the turning chuck of the workpiece reversing device by the loader, since the turning chuck is not located directly above the spindle, the loader head needs to move in the vertical direction and the horizontal direction. There is a problem that the time required for positioning increases at the center of the center.

  The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to set the shaft end on the same side of the two main shafts with the intermediate position between the two parallel main shafts as the turning center. When the workpiece is received from the loader arm at the start end and transferred to the loader arm at the end, the arm that has received the workpiece is This is a quick and low impact reversing device that can be extended and retracted by turning the arm 180 degrees and then turning 180 degrees to reach the end, and then handing the work to the loader arm. is there.

  In order to achieve the above object, the invention described in claim 1 is a work reversing device in a machine tool in which two main shafts that are rotatable while holding a workpiece at the tip are arranged in parallel to each other, An arm that can pass through an intermediate point of a line segment formed by connecting the axes of the two main axes on a plane orthogonal to each other, and can be swung with the axis line orthogonal to the line segment as a pivot axis. An arm extending / contracting mechanism that expands and contracts to the center, and the arm is rotated by 180 degrees forward and backward around the pivot axis and separated by a predetermined amount in the axial direction of the pivot axis on the plane including the same axis ends of the two main axes It includes a turning drive member that is positioned at a position and a hand that is attached to the tip of the arm and operates to hold the workpiece by opening and closing the claw, and the turning radius of the arm when turning the hand can be reduced.

According to the first aspect of the present invention, since the swivel shaft is fixed in the middle of the two main shafts, it is possible to cope easily by changing the arm length even if the dimension between the main shafts which is the main dimension of the machine is widened. . In addition, since the arm extending / contracting mechanism is employed, when the arm is turned, it is easy to make the turning operation by appropriately reducing the turning time, and the time required for turning is shortened.
In addition to the functions of the workpiece reversing device itself, the hand attached to the end of the arm shaft waits at a position close to the pivot axis, the loader head chuck receives the workpiece from the spindle chuck, and directly above the spindle for surface side machining. When the arm stops at the raised position, the arm extends and the work can be gripped by the hand.
The hand holding the workpiece reduces the arm and turns 180 degrees, and the workpiece is reversed. Meanwhile, the chuck of the loader head moves horizontally, moves right above the main spindle for back side processing, and stands by. The work whose arm is extended and reversed is delivered to the chuck of the loader head.

Here, the arm expansion / contraction mechanism means a mechanism for positioning a piston rod with a hand attached to the shaft end by supplying / discharging pressure fluid to / from the cylinder chamber, such as a piston cylinder member. Therefore, the arm expansion / contraction mechanism can be configured using another link mechanism and screw mechanism of the piston cylinder member.
The turning drive member that turns the arm forward and backward by 180 degrees refers to a member that can obtain a turning action by engaging a rack and pinion and moving the rack forward and backward with a piston cylinder member, for example. In addition, it is possible to obtain a turning motion by directly driving the turning shaft by a motor or a hydraulic motor.
In the configuration of the present invention, the reason why the hand swiveling right above the spindle chuck is arranged is that the loader chuck is used to move the workpiece from the spindle chuck to the hand without requiring horizontal movement. This is because the movement is uniaxial and the control can be simplified.

The present invention achieves the following effects by implementing the invention with the above-described means.
According to the first aspect of the present invention, the time required for the turning drive can be shortened since the turning is performed with the arm length of the hand holding the workpiece reduced, and in addition, the power required for the turning drive can be reduced. Have
As a result, there is little impact at the time of starting and stopping of the turning motion, and there is an effect that it is effective in reducing the cost of the entire machine because it is not necessary to strengthen the frame rigidity.
Even if the dimension between two spindles with parallel axes is expanded by changing the shape of the workpiece to be machined, the turning radius of the workpiece does not increase, so that vibration at the time of turning on and off can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a front view of a workpiece reversing device 18 provided between spindles in a two-spindle lathe equipped with a material stocker 14, a product stocker 15, a workpiece transfer loader 13, and two spindle heads 3 and 5, and FIG. FIG. 3 is an operation explanatory view of the work reversing device.

  In FIG. 1, a parallel two-spindle lathe 1 is provided with a first processing unit 16 and a second processing unit 17 that are independently controlled. The first machining section 16 is provided with a first spindle stock 3 and a first tool rest 4 for surface processing, and the second machining section 17 is provided with a second tool rest 6 for a second spindle stock 5 for rear surface processing. Yes. A material for processing is prepared in the material stocker 14. The processing material is transferred to the chuck 7 of the first headstock 3 by the loader head 8 of the work transfer loader 13. The processing material is subjected to surface side processing by the action of the tool of the first tool post 4.

In the 2nd process part 17, the back side of a workpiece | work is processed. Therefore, it is necessary to invert and supply the workpiece to the chuck 9 of the second head stock 5.
By the way, the direction orthogonal to the main axis is defined as the turning axis direction of the work reversing device 18 at a position that bisects the distance between the main axes on the plane orthogonal to the main axis of the first processing unit 16 or the second processing unit 17.

  In FIG. 2, the work reversing device 18 is provided above the midpoint of the line connecting the first spindle stock 3 and the second spindle stock 5. An axis perpendicular to the intermediate point coincides with the axis of the rotating geared shaft 20. Further, a position at which the loader chuck 12 of the loader head 8 of the work transfer loader 13 holds and lifts the work and can be transferred to the hand 19 of the work reversing device 18 is provided at a position vertically above the spindle chucks 7 and 9.

The work reversing device 18 is configured on the base 22 and fixed to the upper surface of the main body frame 10 corresponding to the head stock or the head stock.
The arm extending / contracting mechanism includes a block 21 and a cylinder 26. An arm 11 with a hand 19 holding a workpiece W attached to the shaft end is connected to a rod 27 of a cylinder 26, and the cylinder 26 is attached to a block 21 that can turn around a geared shaft 20.

  The hand 19 opens and closes the claws 11A and 11B that grip the workpiece W by a normal means using electromagnetic force or pressure fluid to grip or release the workpiece W. Further, a cylinder 26 is selected so that the hand 19 does not rotate around the rod 27 when the hand 19 expands and contracts. A turning drive member for turning the arm 180 degrees includes a gear 23, a cylinder 24, and a rack 25.

  The geared shaft 20 is rotatably supported on a base 22 and is provided with a gear 23. A cylinder 24 is installed on the base 22 and a rack 25 is attached. The rack 25 is meshed with the gear 23. The hand 19 is configured to be indexed at a position of 180 degrees around the geared shaft 20 by the advancement and retraction of the rod 28 of the cylinder 24.

Next, the operation of the work reversing device will be described.
In FIG. 3, a series of operations of the work reversing device is as follows.
The workpiece W, which has been gripped by the chuck 7 of the first spindle stock 3 in the first machining section 16 and has finished processing on the surface side by the action of the first tool post 4, is gripped by the loader chuck 12 and lifted to the position P2 directly above.

  In step S1, the hand 19 that has been waiting by opening the nail at the position P1 extends to the position P2. In step S2, the claw of the hand 19 is closed and the loader chuck 12 is opened after gripping the workpiece W. In step S3, the arm 11 of the hand 19 is shortened by the action of the cylinder 26, and the hand 19 returns to the position P1. In step S4, the gear 23 is rotated 180 degrees by the rack 25, and the hand 19 is turned from the position P1 to the position P3 with the geared shaft 20 as the turning center.

While the hand 19 rotates 180 degrees, the loader chuck 12 opens and is positioned at the position P4 and is on standby.
In step S5, the hand 19 moves while extending the arm 11 to the position P4 while holding the workpiece W.
In step S6, the claw of the loader chuck 12 is closed and the claw of the hand 19 is opened after gripping the inverted workpiece W.

In step S7, the opened hand 19 moves from the position P4 to P3, and then turns in the direction opposite to that in step S4, waits again at the initial position of the position P1, and ends the series of operations as the work reversing device.
In step S6, the workpiece W received by the loader chuck 12 is transferred to the chuck 9 of the second headstock 5 waiting directly below, and the machining is continued using the second tool post 6 on the back surface of the workpiece W.

  Although the present invention has been described with respect to the embodiment in which the two main shafts are horizontally arranged, the present invention may be applied to a machine tool in which the main shafts are vertical or inclined as long as the two main shafts are parallel to each other. . In addition, although the expansion and contraction of the hand and the turning are performed as single steps, the hand may be contracted simultaneously with the start of the turning, or the hand may be extended in anticipation of the end of the turning. Of course, other modifications are possible as long as they are within the scope of the present invention.

It is a front view of the work reversing device of the present invention provided in the head stock of a machine tool. It is a top view of a work reversing device. It is operation | movement explanatory drawing of a workpiece inversion apparatus. In the front view of the conventional work reversing device, a swiveling chuck is provided directly above the main shaft corresponding to each of the two main shafts. It is operation | movement explanatory drawing of the workpiece reversing apparatus of FIG. In the conventional work reversing device, the work reversing device is provided with a turning arm that holds a work at the tip of the arm in the middle of two main spindles. A conventional work reversing device, which is provided with a chuck that grips and turns a workpiece at the midpoint between two spindle heads, and reverses the work at that position. A turret lathe with a work reversing device combined with a gantry loader FIG. FIG. 8 is an enlarged view of the work reversing device shown in FIG. 7.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Parallel 2 spindle type lathe 3 1st spindle stock 4 1st tool post 5 2nd spindle stock 6 2nd tool post 7, 9 Chuck 8 Loader head 10 Machine frame 11A, 11B Claw 12 Loader chuck 13 Work conveyance loader 14 Material Stocker 15 Product stocker 16 First processing unit 17 Second processing unit 18 Work reversing device 19 Hand 20 Shaft with gear 21 Block 22 Base 23 Gear 24, 26 Cylinder 25 Rack 27, 28 Rod

Claims (1)

  A work reversing device in a machine tool in which two spindles that can rotate while holding a workpiece at a tip are arranged in parallel to each other, and the axes of the two spindles are connected to a plane perpendicular to the axis of the spindle. An arm capable of turning about an axis passing through an intermediate point of the formed line segment and having an axis perpendicular to the line segment as a turning axis, an arm extending / contracting mechanism for extending and retracting the arm around the turning axis, and the arm around the turning axis And a swivel drive member that is rotated 180 degrees forward and backward and positioned at a position separated by a predetermined amount in the axial direction of the swivel axis on the plane including the same shaft end of the two main shafts, and attached to the tip of the arm A work reversing device characterized in that it can reduce the turning radius of the arm when turning the hand.