JPH0472658B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chuck device for an assembly machine used for automatic assembly in which leads of assembled parts are inserted into holes of parts to be assembled.

``Prior Art'' Conventionally, chuck devices for assembly machines used for assembling electronic components have been known in which the driving source for the chuck opening and closing force is a pneumatic cylinder, a hydraulic cylinder, a spring, or a combination of these. There is. In the automatic assembly of electronic components using these methods, insertion of component leads into through-holes formed in printed circuit boards requires the lowering of an arm such as a robot arm that moves a chuck device to perform assembly operations, and a chuck holding shaft. Although this is done by means such as a servo motor, cylinder, or cam, the force that drives the chuck device itself, that is, the insertion force, is large, so if the insertion is incorrect, the weak component lead will buckle on the top surface of the printed board. As a method for detecting this insertion failure, there are already known methods for checking the presence or absence of leads on the bottom surface of the printed board after component leads are inserted, using electrical continuity, photoelectric elements, or optical recognition. The problem is that the configuration is complex, expensive, and only a consequential detection is performed.

Furthermore, Japanese Patent Application Laid-Open No. 60-90641 discloses a chuck holder that moves in the three-dimensional directions of XYZ, a fixed chuck that has a pair of opposing gripping surfaces protruding from the lower part of the chuck holder, and into which IC leads are fitted. a rod that is attached to the chuck holder so as to be movable up and down and has a cam surface of a predetermined shape formed on a portion of its outer surface; a pusher for pushing an IC that is fixedly attached to the tip of the rod and inserted into the fixed chuck; A pair of lead guide levers are pivotally supported by the chuck holder at both outer positions of the fixed chuck and regulate the position of the IC leads held by the fixed chuck from the outside; an elastic member that biases the guide claw in the opening direction; a first detection section that detects the presence or absence of an IC by the movement of an IC presence/absence detection piece that is protrusively and retractably provided at the lower part of the pusher; A robot hand for IC insertion is disclosed that includes a second detection section that detects the insertion state of the IC by detecting the vertical movement position. In this robot band for IC insertion, when the robot hand is lowered, the leads of the IC opened in a V-shape are fitted into the fixed chuck in a substantially parallel state, and the IC is gripped by the repulsive force of the leads. It can only grip parts with the same chuck size and elasticity.

In addition, the positioning of the IC lead in the through hole is done by lowering a rod with a cam surface formed on its outer surface, and pressing the IC lead from both sides with a lead guide claw whose tip is closed by the cam surface. If the spacing between the holes differs, the rod must be replaced with a rod with a cam surface formed according to the spacing, and there is a problem in that setup changes are required each time the component dimensions differ.

"Problems to be Solved by the Invention" The present invention has been made in view of the above-mentioned problems. It is an object of the present invention to provide a chuck device for an assembly machine that can confirm insertion, accurately obtain appropriate insertion force, and prevent buckling of assembly component leads.

``Means for Solving the Problems'' The chuck device for an assembly machine of the present invention is a chuck device for an assembly machine that grips an assembled part and inserts a lead of the assembled part into a hole of the part to be assembled, and is provided so as to be movable up and down. a chuck block, a chuck pawl provided on the chuck block so as to be openable and closable, and a chuck that opens and closes the chuck pawl in a lowered position by a first driving means at different opening/closing intervals according to the dimensions of a plurality of types of assembled parts. a chuck consisting of a pawl opening/closing mechanism, and a chuck that moves the chuck, grips a desired assembly part with the chuck pawl, moves the lead of the assembly part to just above the upper edge of the hole of the part to be assembled, lowers it, and stops at the position. a moving mechanism; a small-diameter rod that is slidably inserted into the chuck pawl and presses the assembly part by a second driving means when the chuck pawl grips the assembly part; When inserting, the chuck pawl is opened slightly by the chuck pawl opening/closing mechanism to remove the gripping force, and then the small diameter rod is lowered by the second driving means to push out the assembly part directly below, and the to-be-assembled part By detecting the displacement of the insertion mechanism that inserts the lead into the hole and the small diameter rod of the insertion mechanism, it is possible to determine the insertion amount of the lead corresponding to multiple types of assembled parts and whether or not the assembled parts slip off during the movement of the chuck. The insertion force of the small diameter rod by the detection means for detecting and the second drive means of the insertion mechanism is set in advance to prevent buckling of the lead of each assembly part in accordance with the plurality of types of assembly parts. and an insertion force adjusting means for selecting from values.

"Function" When the chuck device for an assembly machine of the present invention grips an assembled part, the first driving means opens the chuck claws at an interval corresponding to the dimensions of the assembled part, and the second driving means grips the chuck claws. The small diameter rod inside the chuck pawl is lowered to press the assembled part, and after confirming that the small diameter rod is pushed up by the assembled part, the chuck pawl is closed again by the first driving means and the assembled part is pressed. grip firmly. Next, the detection means detects that the assembled part has not slipped off from the amount of displacement of the small diameter rod, and detects the insertion amount of the lead depending on the assembled part, and the chuck moving mechanism moves the chuck to just above the upper edge of the hole of the assembled part. It moves, then lowers and stops to accurately position the lead of the assembly part and the hole of the part to be assembled. After the positioning is completed, the chuck pawl is slightly opened by the first driving means of the chuck pawl opening/closing mechanism to remove the gripping force.
At the same time, the insertion force adjustment means is adjusted according to the assembly part.
The second insertion force of the insertion mechanism is selected based on the insertion force selected from a plurality of values set in advance to prevent buckling of the leads of each assembly component corresponding to the plurality of types of assembly components, and the insertion amount detected by the detection means. The small-diameter rod is lowered by the driving means, the assembled part is pushed down directly, and the lead is inserted into the hole of the to-be-assembled part.

"Embodiments" Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the embodiment shown in FIG. The entire chuck device is fixed to an arm 1 by a chuck device holding shaft 2 that can be rotated and raised and lowered.The arm 1 is, for example, a robot arm, and is capable of movements such as rotation. The assembly operation is performed by moving it in a plane perpendicular to the insertion direction. A truncated conical cylindrical case 3 is suspended from the arm 1 via a chuck device holding shaft 2 forming a chuck moving mechanism. A housing 4 is fixed to the lower end of the case 3. The housing 4 has a pentagonal shape, and a pneumatic cylinder chamber 4a and a pneumatic cylinder chamber 4b, which serve as means for raising and lowering the chuck, are vertically provided at each corner, and a piston 5 is fitted into each corner. Air inlets and outlets are provided at the upper and lower ends of the pneumatic cylinder chamber 4a and the pneumatic cylinder chamber 4b, respectively, and piping 19 and piping 20 for supplying compressed air are attached. A box-shaped chuck block 13 is connected to the piston 5 via a cylindrical rod 7.
are fixed by means such as bolts or shrink fitting (not shown).

There are two racks 12 on the chuck block 13.
and a rack 15 is attached slidably in a direction perpendicular to the axis of the rod 7, and the two racks 12, 1
5 are engaged with each other by a pinion 14.
Projections 12a, 1 of each rack 12, 15
Plate-shaped chuck claws 16 and 17 are fixed to 5a. Chuck block 13, rack 12, 1
5, the pinion 14 and the chuck pawls 16 and 17 form a chuck having a chuck pawl opening/closing mechanism. A reduction gear 10 driven by a motor 9 equipped with an encoder 8 for detecting the rotational position is installed in the center of the housing 4.
A thick cylindrical spur gear 11 is mounted on the output shaft 10a at the top and bottom. Even if the piston 5 is driven up and down to raise and lower the chuck, the spur gear 11
The racks 12 are always engaged with each other.

At the center of the rod 7, pneumatic cylinder chambers 7a and 7b having a smaller diameter than the pneumatic cylinder chambers 4a and 4b are provided as means for lowering the piston 30 to which the attachment 31 is attached. A through hole 5a is formed through the piston 5 so that the supplied compressed air flows into the pneumatic cylinder chamber 7a. This pneumatic cylinder chamber 7
A small-diameter piston 30 is fitted into the hole a, and a small-diameter rod 30a serving as an insertion mechanism is attached to the lower end of the piston 30. piston 30
Air from the outside can enter and exit the pneumatic cylinder chamber 7b at the lower part of the pneumatic cylinder chamber 7b. The small diameter rod 30a is loosely inserted into the center of the pinion 14 so that it can slide through the pinion 14, and an attachment 31 with a shape that matches the top surface shape of the assembly part 21 is attached to the tip of the rod 30a, and a screw, etc. It is fixed in place. On the other hand, a permanent magnet 32 is attached to the upper part of the piston 30.
is fixed by a method such as adhesive, and a magnetoelectric transducer 33 is attached to the casing 4 at a position where the magnetic field of the permanent magnet 32 reaches. In order to accurately detect changes in the magnetic field, the housing 4, rod 7, piston 30, etc. are all made of non-magnetic material.

In this embodiment, the housing 4 has five pneumatic cylinder chambers 4a and 4b on the same circumference, and the piston rod 7 of the piston 5 in each pneumatic cylinder chamber
A chuck having chuck claws of different shapes is attached to the chuck. The rack 12 of each chuck is meshed with the spur gear 11. Further, a piston 30 with a small diameter serving as an insertion force adjustment means is fitted into each rod 7, and an attachment 31 suitable for the assembly part 21 to be gripped is fixed to the tip of the small diameter rod 30a of the piston 30. There is.

As shown in FIG. 4, a magnetoelectric conversion element 33 serving as a detection means is connected to an electrical comparator 35 via an amplifier 34 and a switch 36.

The operation of the chuck device for an assembly machine of this embodiment will be explained. First, to explain the gripping operation, a chuck corresponding to the shape of the assembled part is selected from among the five chucks, compressed air is supplied from the piping 19 to the pneumatic cylinder chamber 4a above the piston 5, and the selected chuck is Rod 7 is combined with
and lowers the piston 5. The piston 30 provided within the rod 7 and the small diameter rod 30a are also lowered at the same time. Other chucks remain raised to avoid interference. Thereafter, the arm 1 and the chuck holding shaft 2 are controlled by an electronic control device (not shown), which is a known motor control means, so that the chuck claws 16, 17 are moved to the parts supplying device 2 shown in FIG. 3a.
The assembly part 21 in the supply position 4 is moved to a position where it can be grasped and lowered. At this time, the attachment 31 comes into contact with the upper surface of the assembly part 21 and is pushed up by the assembly part 21 together with the small diameter rod 30a and the piston 30. After confirming that the small diameter rod 30a is pushed up, the chuck claws 16 and 17 are closed to grip the assembly part 21. When gripping the assembly part 21, the chuck pawls 16 and 17 of each chuck open and close by rotating the spur gear 11 via the reducer 10 by the motor 9, so that the rack 12 slides in one direction, and the pinion 14 by sliding the rack 15 in the other direction. The amount of opening of the chuck pawls 16, 17 is detected by an encoder 8 and controlled by an electronic control device which is known motor control means. With this, the gripping operation of the assembled parts is completed. The assembly part 21 gripped by the chuck claws 16 and 17 is moved to the upper part of the printed board 23 by the arm 1. While the arm 1 is moving, the small diameter rod 30a is attached to the attachment 31.
Since the assembly part 21 is pressed against the upper surface of the assembly part 21 through the
If the assembly part 21 slips down between the parts, the small-diameter rod 30a and the piston 30 descend, so that the permanent magnet 32 and the magnetoelectric transducer 33 detect the slippage of the assembly part 21, as will be described later. By confirming the missing parts of assembly parts before the assembly operation, the loss time until the reassembly operation is shortened.

Next, the assembly operation of parts will be explained. Piping 1
The compressed air that continues to be supplied from 9 to the large diameter pneumatic cylinder chamber 4a is passed through the through hole 5 of the piston 5.
Since the piston 30 enters the small-diameter pneumatic cylinder chamber 7a through the piston 30, a relatively small thrust is applied to the piston 30, and the assembly 21 is pushed down by the attachment 31. The chuck claws 16, 17 grip the assembled part 21 to prevent it from falling off, and the arm 1 and the chuck device holding shaft 2, which constitute the aforementioned chuck moving mechanism, move it to the assembly position shown in FIG. 3b and lower it. This descending distance is such that the tip of the component lead 25 descends to just above the upper edge of the hole 26 of the printed circuit board 23, and the chuck device holding shaft 2 stops descending to complete the positioning. Thereafter, the chuck claws 16 and 17 that gripped the assembly part 21 are opened slightly (e.g., e ₂ =0.1 mm in FIG. 3b) by rotation of the motor 9 to the extent that the gripping force is removed. Then, the piston 30 is moved by the compressed air that is still being supplied to the small-diameter pneumatic cylinder chamber 7a.
The assembly component 21 is pushed down with a relatively small force through the small-diameter rod 30a and the attachment 31, and the component lead 25 is inserted into the hole 26 of the printed board 23. The amount of movement of this piston 30 is transferred to a magnetoelectric conversion element 33 via a permanent magnet 32.
is output in analog form as the insertion amount of the component lead 25 as shown in FIG. This output voltage is applied to amplifier 3.
4 and compared with the reference voltage Vref by an electric comparator 35 shown in FIG. Detects that it has been inserted up to the position. Here, the compressed air pressure supplied to the pneumatic cylinder chamber 4a and further to the pneumatic cylinder chamber 7a is set to a pressure that provides an appropriate insertion force of, for example, 0.2 kg so that none of the component leads 25 buckle.
Control by known means such as a pressure reducing valve.

In the chuck device for an assembly machine of this embodiment, there are five types of chucks, but one set of chuck claws
The opening amount of the openings 6 and 17 can be varied according to the dimensions of the assembly part 21, and the insertion amount can also be detected by changing the reference voltage Vref for comparison based on a command from an electronic arithmetic unit (not shown).
It can be changed arbitrarily according to the assembled parts, and by selecting the chuck to be used and switching the switch 36, it can be used to grasp parts of multiple shapes (16 shapes in this example), check whether the parts have slipped, and detect the insertion amount. have the ability to respond.

In this embodiment, the large-diameter pneumatic cylinder chamber 4a and the piston 5 are used to lower the chuck claws 16, 17, and the small-diameter pneumatic cylinder chamber 7a and the piston 30 provided in the rod 7 of the piston 5 are used to lower the chuck claws 16, 17. Since the rod 30a and the attachment 31 are lowered and the compressed air from the large diameter pneumatic cylinder chamber 4a is introduced into the small diameter pneumatic cylinder chamber 7a, two pistons 5 and 30 can be operated by one power source. They can be moved at the same time, and the device is simple and easy to control.

In this embodiment, five types of chucks are arranged on the same circumference in a housing and are attached to a chuck opening/closing mechanism driven by a motor. It may be attached.

Also, a pneumatic cylinder chamber 4a for raising and lowering the chuck
By controlling the pressure of the compressed air supplied to the piston 30, the thrust of the piston 30, that is, the small diameter rod 30a
We have explained how to limit the insertion force, but if you want to further reduce the insertion force, compressed air supplied from the piping 20 to the pneumatic cylinder chamber 4b for raising the chuck is transmitted to the pneumatic cylinder chamber 7a. A small hole is provided in the rod 7 as shown in FIG.
Highly compressed air (e.g. 4Kg/cm ² ) is supplied to the pneumatic cylinder chamber 4b, and low compressed air (e.g. 0.5Kg/cm ² ) is supplied to the pneumatic cylinder chamber 4b.
If the piston 5 is driven by the pressure difference, the piston 30 and the small diameter rod 30a are driven by the low compressed air flowing from the pneumatic cylinder chamber 4b.
The thrust becomes even smaller, for example, 0.1Kg. The air pressure supplied to the pneumatic cylinder chamber 4b is arbitrary in proportion to the insertion force. In addition, when gripping a fragile assembly part with a weak force (for example, 0.5 kg), stop the supply of low compressed air to the pneumatic cylinder chamber 4b and open it to the atmosphere to keep the pneumatic cylinder chamber 7a at atmospheric pressure. For example, during the transfer of assembled parts, the parts will not be pushed out by the thrust of the piston 30 and by extension the small diameter rod 30a.

In this example, a pneumatic cylinder was used to raise and lower the chuck and lower the attachment.
A hydraulic cylinder may also be used.

In addition, in this embodiment, in order to downsize the chuck device, a non-contact method that combines a permanent magnet and a magneto-electric transducer to detect the insertion amount has been explained as an example, but as an example, a known proximity switch, differential Using a transformer and/or a sliding linear potentiometer, the piston 30, small diameter rod 30a
Alternatively, the amount of movement of assembly parts may be detected.

"Effects of the Invention" The chuck device for an assembly machine of the present invention has the above-described configuration, and when gripping an assembled part, the first drive means opens the chuck claws at an interval corresponding to the dimensions of the assembled part. , the small diameter rod inside the chuck pawl is pressed against the assembled part by the second driving means, and after confirming that the small diameter rod is pushed up by the assembled part, the chuck pawl is moved again by the first driving means. The chuck is closed to securely grip the assembled part, and then the detection means detects that the assembled part has not slipped off based on the amount of displacement of the small diameter rod, and detects the insertion amount of the lead depending on the assembled part. The chuck is moved to just above the upper edge of the hole of the to-be-assembled part and then stopped, and the lead of the assembling part and the hole of the to-be-assembled part are accurately positioned. After the positioning is completed, the first driving means of the chuck pawl opening/closing mechanism is moved. The chuck claws are opened slightly to remove the gripping force,
At the same time, the insertion force adjustment means is adjusted according to the assembly part.
The second insertion force of the insertion mechanism is selected based on the insertion force selected from a plurality of values set in advance to prevent buckling of the leads of each assembly component corresponding to the plurality of types of assembly components, and the insertion amount detected by the detection means. Since the small diameter rod is lowered by the driving means and the assembled part is pushed straight down and the lead is inserted into the hole of the assembled part, the appropriate insertion force can be obtained with high precision, and there is no strain on the chuck claw opening/closing mechanism or the insertion mechanism. It has the excellent effect of not applying any force. In addition, by pressing the small diameter rod against the assembly part when the assembly part is gripped, slipping of the assembly part during movement of the chuck device can be detected by the displacement of the small diameter rod. By checking for missing parts, the loss time until reassembly can be shortened, and by detecting the amount of insertion of the assembly component lead into the hole of the assembled component based on the displacement of the small diameter rod, the predetermined It is possible to confirm with high accuracy and low cost that the lead has been inserted into the correct position.Furthermore, the assembly component lead can be inserted using a small diameter rod with arbitrarily variable thrust that is separate from the chuck moving mechanism. , it is possible to insert multiple types of parts with different insertion forces into one type of chuck, and not only can the lead insertion amount be detected according to the type of assembled parts, but also the lead can be inserted with an appropriate insertion force that will not buckle. It has excellent effects such as being able to be inserted.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is a longitudinal sectional view of the embodiment shown in FIG. 1, FIG. 3a is a side view of the chuck of the embodiment shown in FIG. 1 gripping an assembled part, and FIG. is a side view of the state in which the assembled component is inserted from the top surface of the printed board, FIG. 4 is a block diagram of the circuit that detects the amount of insertion of the assembled component, and FIG. 5 is the output detected by the displacement amount detection means of the assembled component. FIG. 3 is a characteristic diagram showing the relationship between voltage and insertion amount of assembly parts. 1...Arm, 2...Chuck device holding shaft, 4
...Housing, 4a, 4b...Pneumatic cylinder chamber, 5a
... Through hole, 7 ... Rod, 7a, 7b ... Pneumatic cylinder chamber, 11 ... Spur gear, 12, 15 ...
Rack, 13...Chuck block, 14...Pinion, 16,17...Chuck pawl, 19,20
... Piping, 21 ... Assembly parts, 25 ... Parts leads, 26 ... Assembled parts holes, 30 ... Pistons,
30a...Small diameter rod, 31...Attachment, 32...Permanent magnet, 33...Magnetoelectric conversion element,
35...Electric comparator.

Claims (1)

[Scope of Claims] 1. A chuck device for an assembly machine that grips an assembled part and inserts a lead of the assembled part into a hole of the assembled part, comprising: a chuck block that is movable up and down; a chuck comprising a chuck pawl, and a chuck pawl opening/closing mechanism that opens and closes the chuck pawl in a lowered position by a first driving means at different opening/closing intervals according to the dimensions of the plurality of assembled parts; and a chuck that moves the chuck. a chuck moving mechanism that grips a desired assembly part with the chuck pawl, moves the lead of the assembly part to just above the upper edge of the hole of the to-be-assembled part, lowers it, and stops at the position; inserted into the
a small-diameter rod that presses the assembly part using a second driving means when the assembly part is gripped by the chuck pawl; and a small-diameter rod that presses the assembly part by a second drive means when the assembly part is gripped by the chuck pawl; After the force is removed, the small diameter rod is lowered by the second driving means to push the assembled component directly downward, and the lead is inserted into the hole of the assembled component; a detection means for detecting the amount of lead insertion corresponding to a plurality of types of assembly parts and the presence or absence of slipping of the assembly parts during movement of the chuck by detecting the amount of displacement; An assembly machine characterized by comprising an insertion force adjusting means for selecting the insertion force of the rod from among a plurality of values set in advance in correspondence with a plurality of types of assembly parts so that the leads of each assembly part do not buckle. chuck device.