JPH06296097A - Mounting device for electronic component - Google Patents

Abstract

PURPOSE:To enable a table to move smoothly by two motors. CONSTITUTION:A mounting device for electronic components is equipped with a pair of speed directing sections 31 and 32 wherein target position data of a device control 30 are inputted and which send speedv directions to a pair of servo drivers 33 and 34 that drive motors M1 and M2 and a cooperative action control A wherein position data of a pair of encoders E1 and E2 are inputted and which obtains the accelerations a1 and a2 of a pair of feed nuts basing on the above position data, compares the acceleration a1 and a2 with each other so as to get correction signals k1 and k2, and outputs the signals k1 and k2 to the speed directing sections 31 and 32 so as to move the pair of feed nuts at an equal speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting apparatus in which a pair of motors can move a table at a high speed with less vibration.

[0002]

2. Description of the Related Art An electronic component mounting apparatus is widely used in which a substrate is fixedly supported by a positioning portion, a nozzle of a transfer head is moved in the XY directions with respect to the substrate, and electronic components are mounted on the substrate from a parts feeder. ing. Of these, the table for holding the transfer head is formed small and light, and this small table is moved by a larger table. Both ends of this large table are moved by two independent motors. A known electronic component mounting apparatus is known.

FIG. 4 is a plan view showing a moving device of the transfer head 7 in such an electronic component mounting apparatus. Figure 4
Among them, M1 and M2 are a pair of motors for moving the X table 3, and 1 and 2 are a pair of feed screws driven by the motors M1 and M2, respectively, and are oriented in the Y direction. Further, feed nuts 4 and 5 are provided at both ends of the X table 3, and these feed nuts 4 and 5 are respectively screwed into the feed screws 1 and 2. Therefore, when the two motors M1 and M2 are driven in cooperation with each other, the X table 3 can be moved in the direction of the arrow N1 at a higher speed than when driven by only one motor. The engaging Y table 6 and the transfer head 7 held by the Y table 6 can be moved at a high speed to realize a quick mounting operation.

[0004]

However, such a configuration has the following problems.
That is, if the Y table 6 is moved from the solid line position in FIG. 4 to the chain line position and moved in the arrow N2 direction while moving the X table 3 in the arrow N1 direction, the center of gravity position in the X direction is from the position G1. Move like position G2. As a result, the load on the motor M1 and the load on the motor M2 change. For example, at the position shown by the solid line in FIG. 4, the load on the motor M1 is larger than the load on the motor M2.
The opposite is true at the position of the chain line. As described above, in the conventional electronic component mounting apparatus, no consideration is given to the load variation of the motors M1 and M2 due to the movement of the table 6 that holds the transfer head 7, and the feed nut 4 and There is a problem that a difference in moving speed is generated between the feed nut 5 and vibration as a result, which makes it difficult to move the table smoothly. In addition, the feed nut on the side with a lighter load tends to move faster and the feed nut on the other side tends to move slower, which causes a problem that abnormal wear is likely to occur on the feed screw.

Therefore, an object of the present invention is to provide an electronic component mounting apparatus capable of moving a transfer head smoothly and at high speed by a pair of motors.

[0006]

An electronic component mounting apparatus according to the present invention inputs a target position information of an apparatus control section and sends a speed instruction to a pair of servo drivers which drive respective motors. Input the position information of the pair of encoders, compare the acceleration of the pair of feed nuts obtained from this position information, and send a correction signal to the pair of speed command parts so that the pair of feed nuts move at a constant speed. It has a cooperative operation control unit for outputting.

[0007]

With the above structure, the cooperative operation control section compares the accelerations of the pair of feed nuts and sends a correction signal to the speed command section on the side with the larger acceleration. As a result, the speed of the motor on the higher moving speed side is controlled to be slower in accordance with the speed of the motor on the lower moving speed side. For this reason, it is possible to realize smooth table movement while suppressing problems such as vibrations and the like due to the load variation. Even in this case, since the second table moves together with the slow feed nut, the table moving speed is not reduced at all.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a perspective view of an electronic component mounting apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram thereof, and FIG. 3 is an explanatory diagram of correction signals. In FIG. 1, the same components as those of FIG. 4 according to the conventional means are denoted by the same reference numerals, and the description of the configuration is omitted. Now, at the center of the base F, a conveyor 8 is provided as a positioning unit that faces the X direction.
The substrate 9 is supported at a predetermined position on the transfer conveyor 8. Reference numeral 10 denotes a parts feeder for the electronic parts P arranged side by side in the front part of the conveyer conveyor 8. In both parts of the parts feeder 10, the pair of base parts 13 and 14 are Y by the feet 11 and 12.
It stands upright. This pair of base parts 13, 1
A pair of guide rails 15 and 16 slidably engaged with sliders 17 and 18 provided below both ends of the X table 3 serving as a second table are provided in parallel with each other in the horizontal plane. ing. Reference numerals 19, 21 and 20, 22 are bearings for axially supporting the feed screws 1, 4 in the Y direction, and E1, E2 are servomotors M1, respectively.
The encoder is a position detector that detects the rotation amount of M2 and detects the position information of the feed nuts 4 and 5, that is, both ends of the X table 3. Therefore, when the servomotors M1 and M2 are driven, the X table 3 moves in the Y direction. 23 is a moving body connected to the Y table 6 as the first table, and the feed nut of this moving body 23 is the X table 3
While being screwed into the X-direction feed screw 24 built into the
The moving body 23 is slidably engaged with the X-direction guide rod 25. Reference numeral 26 is a motor for driving the feed screw 24, and N is a nozzle which is held by the transfer head 7 and sucks the electronic component P.

In FIG. 2, reference numeral 30 denotes a device control unit such as a CPU, which outputs target position information in the Y direction to the speed command units 31 and 32 on the respective sides of the servomotors M1 and M2. Reference numerals 33 and 34 denote servo drivers that input the corrected speed command from the speed command units 31 and 32 and supply a drive current to the servo motors M1 and M2. Further, the cooperative operation control unit A
Input the position information of encoders E1 and E2,
Acceleration detection units 35 and 36 that differentiate acceleration to detect acceleration
And the outputs a ₁ and a _{2 of} these acceleration detectors 35 and 36.
And a comparator 37 that outputs a difference Δa between them,
This difference Δa (= a ₁ −a ₂ ) is input, and a speed correction command unit 38 that outputs the correction signals k ₁ and k ₂ to the speed command unit 31 or the speed command unit 32 in accordance therewith is formed.
FIG. 2 shows the contents of the correction signals k ₁ and k ₂ .
When Δa is positive (a ₁ > a ₂ ), the X table 6 is located on the servo motor M2 side, and the load on the servo motor M2 is larger. That is, the feed nut 4 driven by the servomotor M1 is in a state of being easier to move. Therefore, the speed correction command unit 38 sends the correction signal k ₁ to the speed command unit 31 on the servo motor M1 side, and the corrected speed command reduced by the amount f (Δa) corresponding to the difference Δa is the speed command unit 32. Output to the servo driver 33, and the servomotor M1 rotates slowly accordingly. As a result, the slow servo motor M2 and the fast servo motor M1 operate in cooperation with each other. Conversely, when Δa becomes negative (a ₂ >
a ₁ ) is the reverse process of the above. Needless to say, when Δa becomes zero (a ₁ = a ₂ ), the speed correction command section 38 does not send any correction signal.

[0011]

According to the electronic component mounting apparatus of the present invention, a pair of speed command sections for inputting target position information of the apparatus control section and sending a speed command to a pair of servo drivers for driving respective motors, and a pair of speed command sections. Coordinated operation that inputs the position information of the encoder, compares the acceleration of a pair of feed nuts obtained from this position information, and outputs a correction signal to the pair of speed command parts so that the pair of feed nuts move at a constant speed. Since it has a control unit, the second table will not move as the first table moves.
Even if load fluctuations occur in the pair of motors that move the table, the transfer head can be moved smoothly without causing problems such as vibration.

[Brief description of drawings]

FIG. 1 is a perspective view of an electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of an electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a correction signal of the electronic component mounting apparatus according to the embodiment of the present invention.

FIG. 4 is a plan view showing conventional means.

[Explanation of symbols]

 1 Feed Screw 2 Feed Screw 4 Feed Nut 5 Feed Nut 7 Transfer Head 9 Substrate 10 Parts Feeder 30 Device Control Section 31 Speed Command Section 32 Speed Command Section 33 Servo Driver 34 Servo Driver P Electronic Component N Nozzle

Claims (1)

[Claims] 1. A nozzle for picking up an electronic component from a parts feeder and mounting it on a positioned substrate, a transfer head for holding the nozzle, and a transfer head for the first transfer.
Of the first table for movably holding the first table, the second table for movably holding the first table in the second direction orthogonal to the first direction, and the second table of the second table. A pair of feed nuts provided at both ends, a pair of feed screws screwed into the pair of feed nuts, a pair of motors that independently drive the pair of feed screws, and a pair of feed nuts, respectively. An electronic component mounting apparatus including a pair of position detectors for detecting position information, which inputs target position information of a device control unit and sends a speed command to a pair of servo drivers for driving the respective motors. The position information of the pair of speed command sections and the pair of encoders is input, the accelerations of the pair of feed nuts obtained from this position information are compared, and the pair of speed command sections are fed to the pair of speed command sections. An electronic component mounting apparatus having a cooperative operation control unit that outputs a correction signal so that the nut moves at a constant speed.