JP2000287497A - Device for correcting angle error of stepping motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for correcting the angle error of a stepping motor which can raise the angle accuracy of a stepping motor without raising the processing accuracy and besides can keep this stepping motor and the angle error property unified. SOLUTION: This device is equipped with a storage means 61 which stores the angle error property that a specified stepping motor 45 has, a correction means 65 which corrects the step pulse of the stepping motor 45 based on the angle error property stored in the storage means 61, and a control means 68 which controls the drive of the stepping motor 45 based on the step pulse corrected by the correction means 65. The storage means 61 is mounted on the stepping motor 45.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stepping motor incorporated in, for example, a mounting head of an electronic component mounting device (high-speed mounter), and more particularly to an angle error correction device for a stepping motor.

[0002]

2. Description of the Related Art In a high-speed mounter, a plurality of mounting heads are mounted on a rotary table corresponding to a plurality of stop positions including an electronic component suction position and a mounting position. In each mounting head, a plurality of suction nozzles are mounted concentrically, and a stepping motor having a rotating table side as a stator and a suction nozzle side as a rotor is incorporated. Then, by appropriately rotating the stepping motor, an arbitrary one of the suction nozzles to be used is selected from among the plurality of suction nozzles, or the angle of the electronic component sucked by the suction nozzle is corrected (for example, for example). And JP-A-8-321698).

[0003]

Since the angular accuracy of the stepping motor depends on the machining accuracy of the teeth of the stator, etc., when high angular accuracy is required for the above-mentioned stepping motor, the angular accuracy of the teeth of the stator is increased. It is necessary to increase the processing accuracy or to correct the step pulse of the corresponding motor driver (drive circuit) based on the individual angle error characteristics of the stepping motor. The former method is more preferable because the cost is high and the processing accuracy is limited. However, according to the latter method, since the angle error characteristics incorporated in the motor driver are individual to the motor, when replacing the mounting head (stepping motor) due to failure or maintenance, it is necessary to also replace the corresponding motor driver. It is assumed that the work becomes complicated. In addition, mistakes such as an incompatibility between the replaced stepping motor and the motor driver are also assumed.

According to the present invention, the angle accuracy of a stepping motor can be improved without improving the machining accuracy, and the angle error of the stepping motor can be integrated with the angle error characteristics of the stepping motor. It is an object to provide a correction device.

[0005]

SUMMARY OF THE INVENTION An angle error correction device for a stepping motor according to the present invention is based on a storage means for storing an angle error characteristic of a specific stepping motor, and an angle error characteristic stored in the storage means. Correction means for correcting the step pulse of the stepping motor, and control means for controlling driving of the stepping motor based on the step pulse corrected by the correction means, wherein the storage means is mounted on the stepping motor. And

According to this configuration, the step pulse of the stepping motor is corrected based on the angle error characteristic (data) stored in the storage means, and the driving of the stepping motor is controlled by the corrected step pulse. Therefore, the angular accuracy of the stepping motor can be significantly improved. Further, since the storage means is mounted on the stepping motor, the stepping motor and its angular error characteristics (data) can always be integrated, and the correction means and the control means are
It can be a general-purpose motor that is not limited by the angle error characteristics of each motor.

In this case, the storage means is preferably a ROM chip.

According to this configuration, the storage means can be easily mounted on the stepping motor.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electronic component mounting apparatus (high-speed mounter) equipped with a stepping motor angle error correction apparatus according to an embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a side view of the electronic component mounting apparatus, and FIG. 2 is a plan view thereof. As shown in FIGS. 1 and 2, the electronic component mounting apparatus 1 includes a supply system 3 for supplying an electronic component A and a mounting system 4 for mounting the electronic component A on a board B in parallel with each other with the apparatus main body 2 interposed therebetween. Is arranged. The apparatus main body 2 is provided with an index unit 11 serving as a main body of a drive system, a rotary table 12 connected to the index unit 11, and a plurality of (12) mounting heads 13 mounted on an outer peripheral portion of the rotary table 12. Rotating table 12
Is mounted on the mounting head 13 by the index unit 11.
Are rotated intermittently at an intermittent pitch corresponding to the number of. When the rotary table 12 rotates intermittently, the suction nozzles 14 mounted on each mounting head 13 face the supply system 3 and the mounting system 4 as appropriate, and after sucking the electronic component A supplied from the supply system 3,
It is rotated and transported to the mounting system 4 and mounted on the substrate B introduced into the mounting system 4.

The supply system 3 includes an electronic component A mounted on the board B.
The tape cassette 21 is detachably mounted side by side on a supply table 23 slidably guided by a pair of guide rails 22, 22. A ball screw 24 is screwed into the supply table 23 in the sliding direction.
The forward / reverse rotation of the feed motor 25 connected to one end of the ball screw 24 advances and retreats, and the desired tape cassette 21 is selectively brought to the suction position of the mounting head 13. In each tape cassette 21, a carrier tape C loaded with electronic components A at a predetermined pitch is mounted in a state of being unwound on a tape reel 26. The electronic components A are unwound from the tape reel 26. From carrier tape C
It is sucked by the suction nozzle 14.

The mounting system 4 includes an XY table 31 for moving the mounted substrate B in the X-axis direction and the Y-axis direction, a carry-in transport path 32 and a carry-out transport path 33 disposed before and after the XY table 31, A substrate B on the transport path 32 is transferred to the XY table 31, and a substrate transfer device 34 that simultaneously transfers the substrate B on the XY table 31 to the unloading transport path 33. Substrate B sent to the downstream end of carry-in conveyance path 32
Is transferred onto the XY table 31 by the substrate transfer device 34, and at the same time, the substrate B on the XY table 31 on which the mounting of the electronic component A is completed is transferred to the unloading conveyance path 33 by the substrate transfer device 34. The board B introduced on the XY table 31 is appropriately moved by the XY table 31, and corresponding to the electronic components A sent one after another by the respective mounting heads 13, the component mounting portion faces the mounting position. Electronic components A are received from each suction nozzle 14.

The apparatus main body 2 has an index unit 11 serving as a main component of a drive system on a support base 15. The index unit 11 intermittently rotates the rotary table 12 and synchronizes with the intermittent cycle of the rotary table 12. (Linked), and various devices of the device main body 2 are operated.

The rotary table 12 is fixed to a vertical shaft 16 hanging from the index unit 11, and rotates intermittently clockwise in a plan view. On the outer periphery of the turntable 12,
Twelve mounting heads 13 are attached via a bracket 17 at equal intervals in the circumferential direction so as to be vertically movable. In this case, the intermittent rotation of the rotary table 12 is performed by the mounting head 1.
In accordance with the number 3, each intermittent rotation has a 12 intermittent cycle, and each mounting head 13 revolves by this intermittent rotation.
Stops at each of twelve stop positions. And
At the twelve stop positions, in addition to a suction position where the electronic component A is sucked and a mounting position where the electronic component A is mounted, a position where imaging and position correction of the sucked electronic component A is performed, and nozzle switching (replacement) in the mounting head 13 is performed. The position is included.

As shown in FIG. 3, each mounting head 13
A nozzle holder 4 in which a plurality of (about five) suction nozzles 14 arranged at equal intervals in the circumferential direction are respectively mounted so as to be able to protrude and retract.
1 and the nozzle holder 41 are rotatably supported,
The apparatus includes a holder support member 42 attached to the bracket 17 on the apparatus main body 2 side, and a passage member 43 attached to the upper surface of the nozzle holder 41 and having a vacuum passage 44 formed at the axis thereof. A stepping motor 45 having the nozzle holder 41 on the rotor side and the holder support member 42 on the stator side between the nozzle holder 41 and the holder support member 42.
The stepping motor 45 drives the nozzle holder 41 with respect to the holder support member 42.
Rotates. That is, the plurality of suction nozzles 14 revolve around the axis of the nozzle holder 41.

On the upper side of the holder support member 42, an end cam 46 for protruding and retracting each suction nozzle 14 is provided.
An upper bearing 47 is provided between the end cam 46 and the nozzle holder 41.
However, a lower bearing 48 is disposed between the holder support member 42 and the nozzle holder 41, respectively. That is, the nozzle holder 41 is rotatably supported by the holder support member 42 on the fixed side, and the end face cam 46 is rotatably supported by the nozzle holder 41.

On the other hand, the upper part of each suction nozzle 14 is guided by a nozzle guide hole 51 formed in the passage member 43, and the lower part is guided by a roller guide 52 provided in the nozzle holder 41, so that the suction nozzle 14 can move up and down (can move up and down). Is configured. A support block 53 is screwed to the middle upper portion of the suction nozzle 14, and a roller follower 54 that is in contact with the end cam 46 is rotatably supported by the support block 53. Then, by the forward / reverse rotation of the stepping motor 45, one suction nozzle 14 to be used moves to a predetermined position and protrudes from the nozzle holder 41 by a cam action between the end face cam 46 and the roller follower 54,
And the other unused suction nozzle 14 is the nozzle holder 41
Immerse yourself in

As described above, the stepping motor 45 of the embodiment comprises a plurality of suction nozzles 1 mounted on the mounting head 13.
4 revolves, and any one of the suction nozzles 14 protrudes. Also, the electronic component A sucked by the suction nozzle 14
Is slightly rotated for angle correction. On the other hand, the stepping motor 45 is driven via a motor driver 63 based on a command from the host computer 64 (see FIG. 5).

When an extremely small electronic component A is handled, or when the mounting accuracy of the electronic component A on the substrate B is required, the stepping motor 45 is also required to have a high angular accuracy. On the other hand, the stepping motor 45
Has angular error characteristics that individually affect the angular accuracy depending on the machining accuracy of the teeth of the stator. For example, FIG.
In the angular error characteristic of the stepping motor 45 shown in (1), the error changes depending on the rotation angle, and the tendency of the error differs between the forward rotation and the reverse rotation. For this reason, in the present embodiment, the step pulse of the motor driver 63 is corrected based on the angular error characteristics of the stepping motor 45, and the driving of the stepping motor 45 is controlled by the corrected step pulse. .

FIG. 5 shows a control system of the stepping motor 45. Each stepping motor 45 is equipped with a ROM chip 61 storing error characteristic data which is an angle error characteristic of the stepping motor 45 (see FIG. 3). It is connected to the driver 63. On the other hand, each motor driver 63 is disposed above the index unit 11 (see FIG. 1), and has a CPU (correction means) 65 connected to a host computer 64 and a ROM 66 for storing a driver program.
And R as a work area for various data processing such as correction
It has an AM 67, a drive circuit (control means) 68 for driving the stepping motor 45, and a driver interface 69 connected to the ROM chip 61.

The host computer 64 that controls the electronic component mounting apparatus 1 receives a signal from the CPU 6 of the motor driver 63.
When power is input to the CPU 5, the CPU 65 reads error characteristic data from the ROM chip 61 on the motor side into the RAM 67, and corrects the step pulse of the drive circuit 68 based on the error characteristic data. In this state, when a drive command is input from the host computer 64 to the CPU 65, C
The PU 65 drives the drive circuit 68 to control and drive the stepping motor 45 based on the corrected step pulse. The stepping motor 45 of the ROM chip 61
The form of attachment to the device is free, but it is preferable that the device be detachable.

As described above, according to the present embodiment, the step pulse of the drive circuit 68 is corrected by the error characteristic data of the ROM chip 61 mounted on the stepping motor 45. , The angular accuracy of the stepping motor 45 can be improved. Since the ROM chip 61 is mounted on the stepping motor 45, the stepping motor 45 and its angular error characteristics can always be integrated, and when replacing the stepping motor 45, the individual angular error characteristics and the No error occurs in the correspondence between the two. Further, the motor driver 63 reads the error characteristic data from the ROM chip 61 and corrects the step pulse, so that when the stepping motor 45 is replaced, it is not necessary to replace the motor driver 63 correspondingly.

In the above embodiment, the case where the angle error correction device for a stepping motor according to the present invention is applied to a stepping motor incorporated in a mounting head of an electronic component mounting device has been described. It is needless to say that the present invention can be applied to a stepping motor for other uses in which a high angular accuracy is required and which is detached or replaced.

[0023]

As described above, the angle error correcting apparatus for a stepping motor according to the present invention corrects the step pulse of the stepping motor based on the angular error characteristics of each motor. The angle accuracy can be significantly improved. Further, since the storage means is mounted on the stepping motor, the correction means and the control means can be of a general configuration. Therefore, the stepping motor may be replaced together with the storage means, and there is no need to replace the corresponding correction means and control means.

[Brief description of the drawings]

FIG. 1 is a side view of an electronic component mounting device equipped with an angle error correction device for a stepping motor according to an embodiment of the present invention.

FIG. 2 is a plan view of the electronic component mounting apparatus according to the embodiment.

FIG. 3 is a cut side view of the mounting head according to the embodiment.

FIG. 4 is a diagram illustrating an example of an angle error characteristic of a stepping motor.

FIG. 5 is a block diagram showing a control system of the stepping motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic component mounting apparatus 2 Mounting main body 13 Mounting head 41 Nozzle holder 42 Holder support member 45 Stepping motor 61 ROM chip 63 Motor driver 65 CPU 68 Drive circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ikuo Takemura 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. 5H580 AA03 BB09 FA13 FA14 FB03 GG04

Claims (2)

[Claims] A storage unit configured to store an angle error characteristic of a specific stepping motor; a correction unit configured to correct a step pulse of the stepping motor based on the angle error characteristic stored in the storage unit; Control means for controlling driving of the stepping motor based on the step pulse corrected by the correction means, wherein the storage means is mounted on the stepping motor. . 2. The apparatus according to claim 1, wherein said storage means is a ROM chip.