JP2011148020A - Rotary table device and machine tool having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary table device which holds and accurately rotates a plurality of workpieces despite its simple, inexpensive, and compact configuration, has superior durability, and contributes to an increase in machining accuracy. <P>SOLUTION: This rotary table device (110) includes a plurality of rotary tables (130) which support and rotate workpieces (W), respectively. Each rotary table (130) comprises an electric motor (120). The output shaft of each electric motor (120) is connected to the corresponding rotary table (130) coaxially with the rotating center axis to directly rotate and drive the rotary table. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotary table device capable of rotating while holding a plurality of workpieces, and a machine tool including the rotary table device.

  2. Description of the Related Art Conventionally, a rotary table device as shown in FIG. 4 is known as a rotary table device that can hold and rotate a plurality of workpieces in multiple rows.

  As shown in FIG. 4, in the conventional rotary table device 1, for example, workpieces (hereinafter also referred to as workpieces) W are detachably supported on the rotary tables 2 arranged in four rows. Each rotary table 2 is rotationally coupled to a common drive source (electric motor) 6 via a drive mechanism including a worm gear 3, a drive shaft 4, a drive gear 5, and the like.

  Then, by rotating and driving a common drive source (electric motor) 6, each rotary table 2 is rotated in synchronization with each other to access each workpiece W from above, for example, in FIG. For example, predetermined processing can be performed on a plurality of workpieces W at the same time. Such a driving mechanism of the rotary table device is described in, for example, Patent Document 1.

  As an example of the processing of the workpiece W, a zoom cam groove (zoom lens barrel) for guiding a zoom cam constituting a zoom lens driving mechanism of a camera as shown in FIG. 3 is assumed as an example.

JP-A-2005-23100

  However, the conventional rotary table device 1 is configured to transmit the rotational driving force of the common electric motor 6 to each rotary table 2 via the worm gear 3, the drive shaft 4, the drive gear 5, and the like. There was a real situation.

That is,
(1) Indexing / positioning accuracy is low.
Since the rotation of the electric motor 6 is transmitted to the rotary table 2 via several gear mechanisms (3, 5) and a relatively long drive shaft 4, the electric motor 6 is caused by the presence of backlash and shaft twist. Since there is a deviation of the rotation angle position of each rotary table 2 with respect to the rotation angle position, it is necessary to perform indexing / positioning in consideration of the deviation, for example, indexing / positioning work is required for accurate machining. There was a risk of trouble.
In addition, since the indexing / positioning position varies between the rotary tables 2, there is a risk that it is difficult to perform machining accurately without any variation between the rotary tables 2.

(2) Noise and vibration are relatively large.
Since the rotation of the electric motor 6 is transmitted to the rotary table 2 via several gear mechanisms (3, 5) and a relatively long drive shaft 4, a relatively large backlash exists in the drive system. There is a fact that noise and vibration are relatively large.

(3) Low durability.
Since gear mechanism (3, 5) etc. that cannot avoid wear is used, wear progresses according to the period of use and backlash increases, so the indexing / positioning accuracy further decreases, and vibration and noise However, it is necessary to periodically replace overhauled and worn parts, which increases costs, and during that time, it is necessary to suspend the machine tool, resulting in a reduction in production efficiency.

(4) It is difficult to adjust the phase difference in the rotation direction of each rotary table.
The phase difference of each rotary table 2 largely depends on the machining accuracy and assembly accuracy of drive system components such as the gear mechanism (3, 5), and it is necessary to manufacture components such as gears with high accuracy, which increases the manufacturing cost. There is a fear. Even if the phase difference increases due to wear, it is difficult to adjust it. Accordingly, it is necessary to periodically replace the overhauled and worn parts, and the cost is increased. In the meantime, it is necessary to stop the machine tool, and the production efficiency is lowered.

(5) It is difficult to adjust the distance between the rotary tables.
Since each rotary table 2 is driven via the worm gear 3 and the like, the distance between the axes is naturally determined, so that the position of the rotation center axis of each rotary table 2 is fixedly determined. In such a configuration, since it is difficult to adjust the relative position of each cutter arranged corresponding to each rotary table 2 with the rotation center axis, the rotation center axis position of the cutter and the corresponding rotary table 2 It is necessary to increase the product accuracy of the rotary table device so that the rotation center axis can be made to coincide with the predetermined rotation center axis, which may increase the cost.

  The present invention has been made in view of such circumstances, and while being simple, inexpensive and compact, it can hold a plurality of workpieces and rotate each with high accuracy, and has excellent durability and machining accuracy. An object of the present invention is to provide a rotary table device that can contribute to the improvement of the above. It is another object of the present invention to provide a machine tool that includes the rotary table device and can simultaneously process a plurality of workpieces with high accuracy and has excellent durability.

Therefore, the rotary table device according to the present invention is
A plurality of rotary tables that are rotated while supporting the workpiece are provided,
An electric motor is provided for each rotary table, and the output shaft of each electric motor is coaxially connected to the rotation center axis of the corresponding rotary table and is directly driven to rotate.

  In the present invention, the electric motors can be independently driven and controlled.

  In the present invention, operations can be synchronized between the electric motors.

  A machine tool according to the present invention is provided with the rotary table device according to the present invention, and is characterized in that a plurality of workpieces are supported and processed by corresponding rotary tables.

  According to the present invention, while having a simple, inexpensive, and compact configuration, a plurality of workpieces can be held and each of them can be rotated with high accuracy, and rotation that can contribute to improvement of machining accuracy with excellent durability. A table device can be provided. In addition, it is possible to provide a machine tool that includes the rotary table device and can simultaneously process a plurality of workpieces with high accuracy and has excellent durability.

It is a side view of a machine tool provided with a turntable device concerning one embodiment of the present invention. (A) is a top view which shows the example of 1 structure of the turntable apparatus which concerns on embodiment same as the above, (B) is a side view of (A). It is a perspective view which shows an example of the workpiece (workpiece | work) manufactured with the machine tool which concerns on embodiment same as the above. It is a front view which shows the structural example of the conventional rotary table apparatus.

  Hereinafter, an embodiment of a machine tool provided with a rotary table device according to the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below.

  A machine tool 100 according to the present embodiment (for example, a multi-row (multi-head) NC high-speed milling machine) has a vertical direction in FIG. 1 with respect to a column portion 102 extending upward from a bed portion 101 as shown in FIG. The head unit 104 is supported via the linear motion mechanism 103 so as to be movable. A tool (such as a cutter) 106 having a rotation center axis extending in the vertical direction (substantially vertical direction) is rotatable relative to the machining head 105 in the vicinity of the tip of the machining head 105 that can move up and down of the head unit 104. Is attached. In the present embodiment, a plurality of cutters 106 are arranged in parallel along a direction substantially perpendicular to the plane of FIG. 1 (see FIG. 2).

  Further, the rotary table device 110 is placed on the bed portion 101 via the linear motion mechanism 111 so as to be movable in the left-right direction of FIG.

  The turntable device 110 according to the present embodiment includes a turntable 130 that is rotated about a rotation center axis that is substantially orthogonal to the rotation center axis of the cutter 106 and extends in the left-right direction in FIG. 1, and the turntable 130 is driven. The motor 120 is directly driven to rotate without a gear mechanism or the like.

  That is, in the present embodiment, the rotation center axis of turntable 130 and the output rotation axis of drive motor 120 are connected coaxially.

  A work (workpiece) W is detachably attached to the tip of the turntable 130 via a chuck mechanism or the like, and the work W is rotated integrally with the turntable 130. . As an example of the workpiece W, a zoom lens cylinder having a zoom cam groove as shown in FIG. 3 is assumed.

  As shown in FIG. 2, a plurality of rotating tables 130 (here, for example, four rows are illustrated) are arranged in a substantially horizontal direction (a direction substantially orthogonal to the plane in FIG. 1).

  A drive motor 120 is provided corresponding to each of the plurality of rotary tables 130, and each of the electric motors 120 is configured to be independently rotatable.

  In such a machine tool 100 according to the present embodiment, for example, according to a command from the control device, the rotary table device 110 is moved in the left-right direction in FIG. 1 and the cutter 106 is lowered while rotating at a predetermined rotational speed. Then, the cutter 106 and the workpiece W are brought into contact with each other to start processing. At this time, for example, the work W is maintained in rotation stop by the electric motor 120 at a predetermined torque.

  Thereafter, while rotating the rotary table device 110 in the left-right direction in FIG. 1, each rotary table 130 and each workpiece W are rotated about the rotation center axis by way of the electric motors 120, so that FIG. Zoom cam grooves as shown in FIG. 3 are simultaneously formed around each workpiece W.

  In addition, the rotation direction of the electric motor 120 and the turntable 130 is not particularly limited, and can be rotated in any of clockwise and counterclockwise directions as required. For example, it is also possible to control the rotation of some rotary tables 130 so as to rotate in a direction different from the remaining ones.

  Each electric motor 120 can be a servo motor such as a DD motor (direct drive motor or the like), for example. For example, the position of the knock pin 121 can be used as a reference position (the position can be detected by a built-in encoder or the like). The rotation angle position and the rotation speed can be controlled.

  Accordingly, the indexing / positioning of each electric motor 120 and each rotary table 130 can be performed easily and with high accuracy, and the phase between the plurality of electric motors 120 and the rotary table 130 is also easy and accurate. Can be matched well.

  Thus, according to the present embodiment, a plurality of rotary tables 130 arranged in parallel corresponding to a plurality of (multi-axis or multi-head) cutters 106 are coaxial with the output rotary shaft of each independent electric motor 120. Since the plurality of rotary tables 130 are directly rotated by the independent electric motors 120, the following effects can be obtained.

(1) Indexing / positioning accuracy can be improved with respect to a conventional gear-driven rotary table device.
Compared to the conventional one in which the rotation of the common electric motor 6 is transmitted to the rotary table 2 through several gear mechanisms 3 and 5 and a relatively long drive shaft 4, the electric motors 120 are used. Since the corresponding rotary table 130 is configured to rotate directly, it is possible to eliminate the influence of backlash and torsion of a long shaft, so that the indexing / positioning accuracy can be improved. Product accuracy can be improved.

(2) Noise and vibration can be suppressed.
As described above, since the influence of backlash can be suppressed and the sliding part of the rotary table device according to the present embodiment is only the bearing part, noise and vibration can be suppressed, and the noise is reduced. Can be achieved.

(3) The durability can be improved.
Since there is little influence of wear and the like of the gear mechanisms 3 and 5 in the conventional gear drive type rotary table device, and the sliding part of the rotary table device according to the present embodiment is only the bearing portion, Opportunities and the frequency of replacement of overhauled and worn parts can be reduced, thus reducing costs and high-precision machining for a long time without reducing indexing and positioning accuracy due to increased wear. In addition, since the machine tool stop period can be minimized, the production efficiency can be improved.

(4) The adjustment of the phase difference in the rotation direction of each rotary table is easy and highly accurate.
For example, since the rotation angle position and rotation speed of each rotary table 130 can be controlled with the position of the knock pin 121 as a reference position, the phase difference can be reduced easily and with high accuracy, thereby achieving good synchronization. As a result, the processing accuracy can be improved.
In addition, the drive motor 120 can be synchronously controlled so as to grasp the position of each knock pin 121 and suppress the deviation between the rotary tables to achieve synchronization. Therefore, even if there is a positional deviation or fluctuation of the knock pin 121, it can be adjusted easily and with high accuracy, and therefore the phase difference between the rotary tables increases due to wear of a gear mechanism or the like as in the prior art. There is no such thing, and high-precision processing can be maintained for a long time.

(5) It is easy to adjust or change the distance between the rotary tables.
Instead of the conventional configuration in which each rotary table is driven by a common electric motor via a gear mechanism or the like, the corresponding rotary table 130 is directly rotated and driven by a plurality of electric motors 120. The distance between the electric motors 120 (the rotary table 130) can be easily changed or adjusted, and the distance between the electric motors 120 (the rotary table 130) can be set freely. It can be easily transferred to the machine tools provided. That is, it is possible to provide a user-friendly rotary table that is easy to use.

(6) High-speed rotation is possible compared to a conventional gear-driven rotary table device.
Instead of a conventional configuration in which each rotary table is driven by a common electric motor via a gear mechanism or the like, a configuration in which the corresponding rotary table 130 is directly rotated by a plurality of electric motors 120 (the sliding portion is Since the influence of backlash or the like can be eliminated, the rotating table 130 can be rotated at a high speed, and for example, productivity can be improved.

(7) The use of gear lubricant is unnecessary, which is advantageous in terms of running costs and maintenance, and because there is no waste oil, it is possible to provide a rotary table device that is also environmentally friendly and thus provide a machine tool. It becomes.

(8) Further, in the present embodiment, since the corresponding rotary table 130 is directly rotated by the plurality of electric motors 120, it is possible to execute different machining contents at the same time. Therefore, it becomes easy to cope with various required forms of processing, and high-efficiency and low-cost work can be realized.
Further, for example, the rotation direction of the cutters 106 can be varied between the cutters 106 and the rotation direction of the corresponding rotary table 130 can be varied. Therefore, the cutter 106 extends to the head unit 104. The reaction force can be canceled out, thereby suppressing unnecessary vibrations and the like, thereby improving the machining accuracy and working environment, and further reducing the mechanical rigidity of the machine tool, for example. As a result, it is possible to promote weight reduction and cost reduction.

  As described above, according to the turntable device according to the present embodiment, it is possible to hold a large number of workpieces (workpieces) and rotate each with high accuracy while having a simple, inexpensive and compact configuration. Thus, it is possible to provide a rotary table device that is excellent in durability and can contribute to improvement in processing accuracy.

  2A and 2B show a case in which the four electric motors 120 are fastened and fixed to the common frame member 140 to increase the rigidity, but in FIG. As indicated by the dotted line, there is a request for easy attachment / detachment of the electric motors 120 for layout changes, a request for expansion of adjustment of the mounting position, vibration from other electric motors 120 and the rotary table 130, etc. The frame member 14 can also be divided according to various requests such as reducing the influence of the above.

  In the present embodiment, the case where four rows of rotary tables (and corresponding electric motors) are provided has been described as an example. However, the present invention is not limited to this, and two or more rotary tables (and corresponding ones) are provided. Any device provided with an electric motor can be applied.

  As the electric motor 120, a servo motor capable of controlling the position and speed can be used. MOTOR DiS series; Reference URL: http://www.fanuc.co.jp/en/product/servo/syncbuiltinservo/index.html) can be used.

  The embodiment described above is merely an example for explaining the present invention, and various modifications can be made without departing from the gist of the present invention.

100 Machine tools (machining centers, NC milling machines, etc.)
101 Bed section 102 Column section 104 Head section 105 Processing head 106 Tools (cutter, grindstone, etc.)
DESCRIPTION OF SYMBOLS 110 Rotary table apparatus 120 Electric motor 130 Rotary table W Workpiece (Workpiece)

Claims (4)

A plurality of rotary tables that are rotated while supporting the workpiece are provided,
An electric motor is provided for each rotary table, and an output shaft of each electric motor is coaxially connected to a rotation center axis of the corresponding rotary table and is directly driven to rotate.   The rotary table device according to claim 1, wherein the electric motors are independently driven and controlled.   The rotary table device according to claim 1 or 2, wherein operation is synchronized between the electric motors.   A machine tool comprising the rotary table device according to any one of claims 1 to 3, wherein a plurality of workpieces are respectively supported by a corresponding rotary table and processed.

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