JPH0317400B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to an electronic component insertion device used for mounting electronic circuit boards.

(b) Conventional technology In recent years, circuit board mounting work has become highly automated, and a wide variety of electronic components are now subject to automatic insertion. Conventionally, the mainstream automatic insertion device is one that moves the board with an X-Y table, as described in Japanese Patent Publication No. 57-42238.
The insertion head is of the non-moving type. This type of insertion device is suitable for driving a large number of common axial lead type or radial lead type parts at high speed. By the way, recently,
Automatic insertion is even possible for parts that only have one or two mounted on a single board. Since it would be uneconomical to use the above-mentioned high-speed insertion device to perform such a small amount of insertion work, a relatively simple insertion device using an industrial robot was developed. Unexamined Japanese Patent Publication 1987
Examples include those described in Japanese Patent Application Laid-open No. 199300 and Japanese Patent Application Laid-open No. 58-200600. Simply put, this type of insertion device consists of an arm of a rectangular coordinate robot with two axes, X and Y, an insertion head that picks up electronic components and inserts them into a board, and an insertion head that clinches component leads on the bottom surface of the board. It is equipped with an anvil head that performs
Perform the insertion operation by moving the insertion head and anvil head. The insertion head and anvil head are always aligned in the vertical (Z-axis) direction.

(c) Problems to be Solved by the Invention The above-mentioned small-number parts insertion device picks up parts by extending the arm of the robot toward the parts supply section. However, since the anvil head is always located below the insertion head, the component supply section must be thick enough to fit between the two heads. However, this limitation on the thickness of the component supply section becomes a serious obstacle when attempting to supply large and tall components. The present invention has been made with the object of providing a mechanism capable of solving this problem and smoothing out its operation.

(d) Means for Solving the Problems In the present invention, a component insertion head and an anvil head for clinching component leads on the lower surface of the board are attached to an arm that is linearly moved by a feed screw. The insertion head moves back and forth between the component insertion area and the component receiving area. In contrast, the anvil head follows the insertion head in the component insertion area, but does not extend into the component receiving area. The lack of penetration is due to the offset cylinder deflecting the anvil head relative to the insertion head as the insertion head moves into the component receiving area.
The offset cylinder operates simultaneously with the electric motor that rotates the feed screw, but at this time the electric motor is controlled so as not to end its operation earlier than the offset cylinder.

(E) Function: Since the anvil head does not enter the parts receiving area, it is possible to place a thick parts supply section in this parts receiving area so that it does not fit into the gap between the insertion head and the anvil head. Furthermore, as a characteristic of cylinders in general, it is difficult to control the speed of an offset cylinder so as to draw a smooth deceleration curve, so that an impact occurs at the end of the operation. From the standpoint of positioning accuracy, it is very bad for such a shock to occur when the arm stops and the insertion head is about to grab a component, or when it is about to insert a component.
In the present invention, the offset cylinder is operated at the same time as the electric motor for rotating the feed screw, and the electric motor is prevented from finishing its operation earlier than the cylinder, so that the electric motor is stopped after the impact occurs due to the completion of the operation of the offset cylinder. Since the insertion head is decelerated and brought to a stop, there is no adverse effect on stopping the insertion head.

(F) Example First, the mechanism will be explained based on FIGS. 1 and 2. In the figure, 1 and 2 indicate the electronic component insertion device 10.
1 is an area in the work space, where 1 is a parts insertion area and 2 is a parts receiving area. The electronic component insertion device 10 has a base 11 extending in a direction perpendicular to the paper surface.
An arm base 13 is slidably supported on a rail portion 12 on the base 11. 14
is a feed screw that moves the arm base 13 along the rail portion 12 in a direction perpendicular to the plane of the paper (this is defined as the X-axis direction). Reference numeral 15 denotes an arm supported by the arm base 13 so as to be able to slide in the left-right direction (this is defined as the Y-axis direction) in the figure. Arm 1
5 consists of upper and lower parts, the upper part is made up of a beam 16 and a feed screw 17, and the lower part is made up of a pair of upper and lower beams 18, 18. The beam 16 slidably passes through the arm base 13, and has end plates 19 and 20 fixed to its front and rear ends. The beams 18, 18 also slidably pass through the arm base 13, and have end plates 21, 2 at their front and rear ends.
2 is fixed. Beams 18, 18 are connected to end plates 20
Penetrates freely. That is, the end plate 20 serves to connect the upper and lower parts of the arm 15. The feed screw 17 has a rear end connected to a shaft 24 of an electric motor 23 fixed to an end plate 20, a front end rotatably supported by an end plate 19, and a feed screw 17 passing through a nut portion 25 fixed to the arm base 13. , which gives movement to the arm 15 in the Y-axis direction. 26 is an offset cylinder (air cylinder) fixed to the end plate 20
Then, connect the rod 27 to the end plate 22 and connect the arm 15.
The relative motion in the Y-axis direction in the beam 18,
Give to 18.

The end plate 19 supports the insertion head 28 and the end plate 21 supports the anvil head 29. The insertion head 28 picks and places the electronic component 31 by moving the component chuck 30 up and down using a built-in air cylinder. Reference numeral 32 denotes a circuit board on which the electronic component 31 is to be mounted, and it lies supported by rails 33, 33 so as to be sandwiched between the insertion head 28 and the anvil head 29. The anvil head 29 moves the anvil 34 up and down using a built-in air cylinder. Anvil 34 clinches electronic component leads 35 on the lower surface of substrate 32. Reference numeral 36 denotes a component supply section, which is thicker in the vertical direction than the gap created between the insertion head 28 and the anvil head 19.

The operation of the above mechanism is as follows. First, in order to pick up the electronic component 31 from the component supply section 36, the arm 15 is advanced. At this time, as shown in FIG. It is deviated toward the base 13. Thereby, only the insertion head 28 can be brought onto the component supply section 36 without causing the anvil head 29 to collide with the thick component supply section 36.
After picking up the electronic component 31, the arm 15 is moved back to position the insertion head 28 above the board 32. During this movement, the rod 27 of the offset cylinder 26 is retracted, causing the beam 28 to move forward relative to each other, thereby making the amount of deviation between the insertion head 28 and the anvil head 29 zero. Then, as shown in FIG. 2, the electronic component 31 is inserted into the board 32 and the lead clinch is performed.

As mentioned above, the anvil head 29 can move only within the component insertion area 1. In this area, the anvil head 29 follows the insertion head 28 like a shadow, and the relationship between the component insertion area 1 and the component receiving area 2 is illustrated in a plan view as shown in FIG. 3. A large number of component supply units 36 can be arranged in a horizontal row in the component receiving area 2, but
Regardless of the number of parts supply sections 36, the anvil head 29 is not allowed to enter this area. Considering the movement types of the insertion head 28 here, 1. Movement within the component insertion area (→) 2. Movement within the component receiving area (→) 3. Movement from the component insertion area to the component receiving area (→) 4. Component There are four types of movement (→) from the receiving area to the parts insertion area. The offset cylinder 26 is
In the case of type 3, the action of extending the rod 27 is performed, and in the case of type 4, the action of retracting the rod 27 is performed. Rod 27 for types 1 and 2
maintains a contracted or extended state.
The extension and retraction of the rod 27 takes place at high speed and is stopped by the inherent stroke limit of the offset cylinder 26 or by stop means provided between the beam 18 and the end plate 20. In either case, a shock is generated at the end of the operation. As mentioned above, this impact adversely affects the stopping accuracy of the insertion head 28. This expansion and contraction movement of the rod 27 is performed simultaneously with the type 3 to type 4 movement of the insertion head 28, but the following phenomenon occurs regarding the operation time. That is, in FIG. 4, the moving distance L that the electric motor 23 gives to the arm 15 via the feed screw 17,
The relationship with the time T required for this is shown, and when normal control is performed, a curve as shown in the figure is drawn. On the other hand, the offset cylinder 26
Finish the action with To. Feed screw 17 at time To
If the moving distance is Lo, then if the moving distance is longer than Lo, the offset cylinder 26 is
3, and if the moving distance is shorter than Lo, the offset cylinder 26 is moved to the electric motor 23.
The operation ends after the operation is completed, that is, after the insertion head 28 stops. Needless to say, it is not good to generate a shock when trying to grasp or insert the electronic component 31. Therefore, in the present invention, the following measures have been taken. In other words, when moving a distance less than Lo, the normal control routine requires
Although a time less than To would be sufficient, this time was intentionally extended to a time greater than To so that the deceleration and stop of the electric motor 23 is always the final stage of arm movement. If this situation is illustrated in accordance with FIG. 4, it will become as shown in FIG. In the diagram, exactly
It has been extended to To, but in reality,
Considering the decay time of vibrations caused by impact,
It may be desirable to allow some additional time. If the additional time is too long, the anvil head 29 may enter the component receiving area 2, so the value should be kept within an appropriate range.

An example of a circuit for performing the above control is shown in FIG. In the figure, 40 is a control unit for the electric motor 23, 41 is a parallel-serial converter, 42 is a memory, 43 is a frequency division counter with a fixed frequency division ratio,
Reference numeral 44 represents a frequency division counter capable of varying the frequency division ratio, 45 represents a clock generator, and 46 represents an arithmetic processing section. The reading speed of the memory 42 and the conversion speed of the parallel-serial converter 41 change depending on the frequency division ratio of the frequency division counter 44, so when the arithmetic processing unit 46 instructs the frequency division counter 44 to change the frequency division ratio, The operating time of the electric motor 23 will change. This circuit executes processing according to the control flow shown in FIG.
First, data regarding which parts are to be inserted into which locations on the board 32 is given, and based on this data, the arithmetic processing unit 4
6 creates movement data. The movement type is also determined from here. The frequency division ratio of the frequency division counter 44 is determined from the movement type and the movement distance. Then electric motor 23
and starts the offset cylinder 26. It goes without saying that the electric motor 23 is operated in a speed mode corresponding to the frequency division ratio and finishes its operation later than the offset cylinder 26. After confirming that both the electric motor 23 and offset cylinder 26 have stopped, the next operation begins.

(G) Effects of the Invention In the present invention, only the insertion head enters the component receiving area, so it is possible to combine a thick component supply section for supplying large components, and the range of components that can be handled is increased. expands greatly. Further, even though the arm is provided with an offset cylinder that causes a shock, the shock does not occur after the arm is stopped, so that the desired stopping accuracy can be ensured.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, and FIGS.
3 is an explanatory diagram showing the arrangement relationship between the component insertion area and the component receiving area; FIGS. 4 and 5 are time-distance diagrams illustrating the movement of the arm by the electric motor; FIG. 6 is a control circuit diagram, and FIG. 7 is a flowchart relating to the circuit of FIG. 6. 1... Component insertion area, 2... Component receiving area, 31... Electronic component, 32... Circuit board, 15
... Arm, 17 ... Feed screw, 23 ... Electric motor, 28 ... Insertion head, 29 ... Anvil head, 26 ... Offset cylinder.

Claims (1)

[Scope of Claims] 1. An arm that moves linearly by a feed screw; an electric motor that rotates the feed screw; an insertion head that is supported by the arm and moves back and forth between a component insertion area and a component receiving area; an anvil head which is also supported by the arm and follows the insertion head in the component insertion area to clinch the component lead on the lower surface of the circuit board; an offset cylinder that deflects the anvil head relative to the insertion head when the anvil head moves to a parts receiving area, the offset cylinder being operated simultaneously with the electric motor for rotating the feed screw, and at this time,
An electronic component insertion device characterized by controlling an electric motor so that it does not end its operation earlier than an offset cylinder.