JPH0447480B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an apparatus for mounting small leadless electronic components such as chip capacitors and chip resistors onto a circuit board.

(b) Conventional technology The work of mounting leadless small electronic components (hereinafter simply referred to as "components") involves picking up the components from a component supply device using vacuum suction means, transporting them onto a board,
This involves repeatedly pressing the component against the mounting agent or solder paste applied to the board.
An example of a device for performing such work is disclosed in Japanese Patent Application Laid-Open No. 52-24494.
This can be seen in Japanese Patent Application Laid-Open No. 182795/1983.

Now, in the equipment that performs the above work, the elevation control of the vacuum suction means is usually performed by a cam, and the cam curve is devised so that it can be used when pressing the vacuum suction means against the components in the component supply device or when pressing the vacuum suction means against the substrate. When pressing the parts together, this prevents excessive impact from being applied to the parts. However, as electronic components become more and more chipped, the types of chip parts increase and the thickness and dimensions become more diverse, making it extremely difficult to keep the impact or pressure applied by vacuum suction means to any part within an allowable range. Ta. As a measure to solve this problem, in JP-A-60-66500, the vacuum suction means is driven by a linear motor, and by controlling the linear motor, when the vacuum suction means hits the component or when the suctioned component is pressed against the board, We are proposing a device that maintains the speed at a moderate level when the vehicle is running. By adopting such a device, various problems such as cracking of parts due to excessive impact or mounting errors due to jumping of the vacuum suction means will be solved, but the above-mentioned Japanese Patent Application Laid-Open No. 55-2449 and Japanese Patent Application Publication 1986-
Application to the rotary index table described in Publication No. 182795, in which a large number of vacuum suction means are arranged around the periphery, requires a large number of linear motors to be installed, which significantly increases the mass of the rotating system and increases equipment costs. It is difficult to realize this because of the large size.

(C) Problems to be Solved by the Invention The present invention provides a plurality of vacuum suction means disposed around the periphery of a support means that rotates intermittently in a fixed direction, and places the vacuum suction means on a component supply device or on a substrate. A device that sucks and mounts parts by lowering it each time it comes to the top, and is intended to maintain the impact applied to the parts by the vacuum suction means below a certain level regardless of the thickness of the parts. It is.

(d) Means for solving the problem In the above device, the vacuum suction means is raised and lowered by an elevating body operated by a cam. The elevating body is arranged at necessary locations in addition to a location corresponding to the component supply device and a location corresponding to the board. Of the elevating bodies,
In particular, those assigned to locations where impact on parts should be taken into consideration are connected to the cam via a stroke expansion/contraction means that expands/contracts the operating stroke. The stroke expansion/contraction means includes a seesaw lever that transmits the displacement of the cam to the elevating body, and means that moves the fulcrum of the seesaw lever relative to the seesaw lever itself along the axial direction of the seesaw lever.

(e) Effect Changing the fulcrum position of the seesaw lever changes the amplitude ratio at both ends. In the case of thin parts, the amplitude on the elevating body side is increased to lengthen the movement stroke of the elevating body. In the case of thick parts, the amplitude on the elevating body side is reduced to shorten the movement stroke of the elevating body. As a result, in the case of any part, it is possible to fully utilize the deceleration section in the cam curve to press the vacuum suction means against the part or to press the part against the board. Therefore, even in the case of a thick component, a situation in which the vacuum suction means and the component, or the component and the substrate come into contact before sufficient deceleration is achieved, can be avoided.

(F) Embodiment In the figure, reference numeral 1 denotes a support means that performs intermittent rotation in a fixed direction. The support means 1 consists of an upper rotating body 2 and a lower rotating body 3, both of which have a circular planar shape and are fixed to a vertical index shaft 4. The index shaft 4 stands up from an index device (not shown), and its upper end is supported by a bearing portion 6 of a stationary deck 5 placed over the support means 1. The interior of the index shaft 4 is an air intake passage 7 communicating with a vacuum source (not shown). The support means rotates in steps of 45 degrees, and as shown in Fig. 6, eight work stations are arranged around it, and eight arms 8 are arranged radially from the lower rotating body 3. It stands out. The arm 8 is supported by a slider 9 attached perpendicularly to the circumferential surface of the lower rotating body 3, and is movable in the vertical direction. The slider 9 is pulled up by a spring 10 stretched between it and the upper rotating body 2 until it hits a stopper bolt 11 (FIG. 11) screwed into the upper rotating body 2. The slider 9 has a roller 12 protruding outward, and an elevating body pushes the roller at a predetermined work station to lower the slider 9. The elevating body and its operating mechanism will be described later.

Arm 8 supports a turret 20 at its tip. The turret 20 has a cylindrical shape, fits onto the tip of the arm 8 from the outside, and is rotatable around the axis of the arm 8, that is, around the horizontal axis. A driven gear 21 is fixed to the outward end face of the turret 20. Four types of suction nozzles 22, 23, 24, and 25 of different thickness are formed from the circumferential surface of the turret 20.
They protrude radially at 90° intervals. Each suction nozzle can be retracted toward the center of the turret 20, and is pushed to a protruding position by a spring 26. The center of the arm 8 forms an intake passage 27.
This intake passage 27 is connected to the suction nozzles 22, 23, 2
Among 4 and 25, only the one directly below is the communication hole 2.
8. Reference numeral 29 is a screw plug that closes the end of the intake passage 27, and also serves to prevent the turret 20 from coming off. The arm 8 configured in this manner and its attached elements are collectively referred to as a vacuum suction means 30.

The upper rotating body 2 supports the valve 40. The same number of valves 40 as the arms 8 are provided, and the valves 40 are provided in the same number as the arms 8.
7 and a hose 41. The valve 40 is connected to the intake passage 7 by a hose 42, and the intake passage 27
This is to control the suction on and off. The valve 40 is opened and closed by a lever actuator 43 having a roller at its tip. In other words, the valve opens when the actuator 43 is pushed down.
When this is not the case, the valve is closed. The actuator 43 is controlled by a pusher 45 that is moved up and down by an air cylinder 44 at the work station, by a pusher 47 that is moved up and down by an air cylinder 46 at the work station, and by a bearing at the work station between them. This is done by a pressing plate 48 fixed to the section 6. The pressing plate 48 also serves as a support member for the air cylinders 44, 46, and the pressing elements 45, 47 form a plane substantially continuous with the pressing body 48 when lowered. Since each valve 40 is arranged at a delayed position with respect to the arm 8 to which it belongs, the pressing plate 4
5 and 47 are also located at positions offset from the work station to which they belong.

A component supply device 50 is arranged at the work station. The component supply device 50 feeds a carrier tape 51 for component supply one pitch at a time, and supplies the components 52 one by one to the vacuum suction means 30. The carrier tape 51 is made by embossing a plastic sheet to create recesses for storing the parts 52 one by one, and covering the recesses with a plastic cover film 53. The cover film 53 is peeled off immediately before the component suction position. The parts supply device 50 arranges a large number of such carrier tapes 51 in a direction perpendicular to the plane of the paper (FIG. 1), and by moving the entire carrier tape 51 in a direction perpendicular to the plane of the paper, the carrier tape 51 containing the required part can be selected. It's summery.

XY with board 60 placed on the work station
A table 61 is arranged (FIG. 11). A parts collection box 62 is arranged at the work station. A component attitude determination device 63 is placed at the work station. The posture determining device 63 is constituted by a photo sensor, and is placed at a height such that a light beam crosses directly below a normally suctioned component.

A suction nozzle selection device 70 shown in FIGS. 7 and 9 is disposed at the work station. The main component of this device 70 is an elevator 71 supported by a stationary deck 5. elevator 7
1 is attached to a slider 72 that slides in the vertical direction, and is given vertical movement by a lever 73 that transmits the movement of a cam (not shown). A selector gear 74 is horizontally supported at the bottom of the elevator 71 so as to face the rotation center of the support means 1 .
The selector gear 74 is connected to an electric motor 75 supported by the elevator 71 via bevel gears 76 and 77, and when the elevator 71 descends, it meshes with the driven gear 21 of the turret 20 and transmits the rotation of the electric motor 75 to the driven gear 21. 78 is a stopper that determines the lower limit of the descent of the elevator 71.

A lock pin 80 is attached to the upper surface of the arm 8. The lock pin 80 is held in a holder 81 fixed to the arm 8 so as to be slidable parallel to the axis of the arm 8, and is pushed toward the turret 20 by a spring 82. A total of four grooves 83 are provided on the end face of the turret 20 to receive the tips of the lock pins 80, one groove each behind the suction nozzles 22, 23, 24, and 25. A U-shaped lever receiver 84 is fixed to the rear end of the lock pin 80. The lever receiver 84 is a bell crank type lever 85 supported by the immovable deck 5.
Accept one side of it. The other end of the lever 85 is connected to the elevator 71 by a connecting rod 86.

A lifting body 90 is placed on the work station. When the work station or the device for centering or orienting the suction parts is arranged, the elevating body 90 will also be placed here. The elevating body 90 is a rod-shaped member supported by a bearing portion 91 of the immovable deck 5, and its rotation is stopped by a sliding key 92, so that it can only move up and down. Elevating body 90
A pressing head 93 facing the roller 12 of the slider 9 is fixed to the lower end, and a flange 94 is fixed to the upper end. A spring 95 inserted between the bearing portion 91 and the pressing head 93 pushes the elevating body 90 downward. 96 is a camshaft, and 97 is a cam that rotates together with the camshaft 96 to give movement to the elevating body 90. A stroke expansion/contraction means 100 connects the cam 97 and the elevating body 90, and is constructed as follows. 101 is a small deck fixed on the immovable deck 5, which has a pair of guide bars 102 in parallel with the line connecting the cam 97 and the elevating body 90.
and one screw shaft 103 are both supported horizontally. The guide bar 102 is a slider 104
support. Inside the slider 104, a nut 105 that is screwed onto the screw shaft 103 is installed inside the slider 104.
4 Hold it in a fixed form relative to itself. 10
6 is the roller 107 that contacts the cam 97 and the elevating body 9
It is a seesaw lever having a roller 108 at a different end that lifts a flange 94 of 0. 109
is a hollow shaft pivotally supported by the slider 104, and the seesaw lever 10 is supported by a support frame 110 fixed to the end face.
I support 6. A groove 111 is provided on the upper and lower outer surfaces of the support frame 110, and the seesaw lever 1 is inserted into this groove 111.
Fit the frame-shaped part 112 in the center of 06. The seesaw lever 106 is held so as to be slidable along the groove 111 in the direction of its own axis. A screw shaft 113 is fixed in the frame-shaped portion 112 in parallel with the sliding direction, and the support frame 110 is fixed to this screw shaft 113.
The nut 114 inside is screwed together. Nut 114 does not move relative to support frame 110. Note that the thread pitch of the threaded shaft 113 and the thread pitch of the threaded shaft 103 are the same. A rotating shaft 115 passing through the hollow shaft 109 rotates the nuts 105 and 114. The rotating shaft 115 is connected to the shaft of an electric motor 116 attached to the slider 104 via a joint 117. Gear 1 is installed on the outer surface of the rotating shaft 115.
18 and bevel gear 119 are fixed, and the gear 118
is engaged with a gear 120 that is pivotally supported on the slider 104, and the bevel gear 119 is engaged with a bevel gear 121 that is integrally coupled to the nut 114, respectively. A bevel gear 122 is fixed to the gear 120 and meshes with a bevel gear 123 fixed to the nut 105. The gears 118, 120 have the same number of teeth, and each set of bevel gears 119, 121 and 122, 123 in combination also has the same number of teeth. 124 is a rotary encoder connected to the electric motor 116.

The above device operates as follows. FIG. 11 shows the behavior of the vacuum suction means 30 at the work station. The vacuum suction means 30 that has arrived at the work station stops with the suction nozzle 22 facing downward. Upon arrival, presser 4
5 is in the raised position, and the vacuum suction means 30 is not generating suction force. Here, the elevating body 90 descends to push down the slider 9 and press the suction nozzle 22 against the component 52. This air cylinder 44 lowers the presser 45, the valve 40 is opened, and the suction nozzle 22 sucks the component 52. The vacuum suction means 30 that has attracted the parts 52 rises as the elevating body 90 rises, and is carried from one work station to another by the intermittent rotation of the support 1. During movement, the actuator 43 of the valve 40 continues to be pressed by the pressing plate 48, and the part 5
2 adsorption is not interrupted. At the work station, a posture determining device 63 inspects the posture of the component 52. If the part 52 is attracted in a normal posture as shown in FIG. 11, the light beam of the photo sensor will not be blocked by the part 52, so it is determined that there is no problem. The vacuum suction means 30 that has left the work station arrives at the work station. At the time of arrival, the presser 47 is in the lowered position, and the vacuum suction means 30 continues to suction the component 52. When the vacuum suction means 30 is lowered and the component 52 is pressed against the adhesive applied to the substrate 60, the presser 47 is raised and the valve 40 is opened to release the suction. Note that if the component 52 is attracted in an abnormal position,
At the work station, the vacuum suction means 30 does not descend, and the presser 47 moves to the work station while remaining descended. And here the presser 47
By rising, the vacuum suction means 30 drops the component 52 into the component collection box 62 and moves it to the work station.

The suction nozzle selection device 70 provided at the work station performs the following operations. That is, when the vacuum suction means 30 arrives at the station, the selector gear 74 is located above the driven gear 21 as shown in FIG. 7, and the tip of the lever 85 is inserted into the lever receiver 84. Lock pin 8
0 engages with the groove 83 as shown in FIG. 8, and firmly fixes the turret 20. Here, if it becomes necessary to change the suction nozzle 22 used to another one, use the elevator 71 as shown in FIG.
lowers and engages the selector gear 74 with the driven gear 21. As the elevator 71 descends, the lever 85 also rotates, causing the lock pin 80 to slide against the spring 82. As a result, the lock pin 80 comes out of the groove 83, and the turret 20 becomes rotatable. In this state, the electric motor 75 is driven to rotate the angle turret 20 as much as necessary. Turret 20
When the elevator 71 is raised after completing the angle change, the lever 85 returns to its old position and the lock pin 80 engages with the groove 83 again to lock the turret 20.

The elevating body 90 is moved to the vacuum suction means 30 by the force of the spring 95.
It is the cam 97 that pushes down and gives it vertical movement. A seesaw lever 106 connecting the cam 97 and the elevating body 90 swings about a hollow shaft 109 as a fulcrum, but the fulcrum position changes depending on the thickness of the parts. When targeting a thin component 52 as shown in FIGS. 1 and 4, the support frame 110 is placed in a position close to the cam 97 relative to the seesaw lever 106, so that the amplitude of the roller 108 becomes large. do. For this reason, the operating stroke of the elevating body 90 becomes large, and even though the part 52 is thin, the suction nozzle 22 cannot reach the upper surface of the part 52, or in the work station, it is difficult to press the part 52 against the substrate 60 with appropriate pressure. It becomes possible.

Next, when handling a thick component 52' as shown in FIG.
4 to move the position of the support frame 110 closer to the elevating body 90 relative to the seesaw lever 106. At this time, the nut 105 also rotates, and the relationship between the tooth number ratios of each gear and the screws 103, 11
3, the slider 104 moves relative to the seesaw lever 106 in the same direction and the same distance as the support frame 110. For this reason,
The relative position of the seesaw lever 106 with respect to the cam 97 and the elevating body 90 remains the same, but only the fulcrum position moves toward the elevating body 90, the amplitude of the roller 108 becomes smaller, and the suction nozzle 22 takes advantage of the deceleration curve of the cam 97. Then, the component 52' is approached and the component 52' is pressed against the substrate 60.

If, for example, a pulse motor is used as the electric motor 116, the stroke expansion and contraction of the elevating body 90 can be precisely controlled numerically. When the seesaw lever 106 swings, the electric motor 116 is left in a free rotation state. At this time, the nuts 105 and 104 rotate slightly due to vibration, and the slider 104 and the support frame 1
10 and the seesaw lever 106, the rotational position of the electric motor 116 is checked from time to time using the rotary encoder 124 to calibrate the deviation. Note that if the stroke extension/contraction means 100 is provided in all the work stations that require adjustment of the operating stroke of the elevating body 90, there is a risk of interference between the stroke extension/contraction means; however, this can be avoided by shifting the arrangement up and down. Solvable. Also, the stroke expansion/contraction means 100
does not necessarily have to be attached to all elevating bodies 90. If it is possible to employ a structure that alleviates the impact on the parts by devising a supporting base, as exemplified in Japanese Patent Application Laid-Open No. 61-135197, the work station can be omitted.

(G) Effects of the Invention According to the present invention, it is possible to expand and contract the vertical stroke applied to the vacuum suction means by the cam according to the thickness of the component, and to maintain the impact applied to the component below a certain level. . In addition, the stroke expansion/contraction means only need to be placed at the necessary work station.
No significant cost increase will be incurred. Furthermore, since the stroke is extended or contracted by moving the fulcrum within the seesaw lever, the cam curve itself is not deformed even if the stroke is extended or contracted, and the movement as intended by the cam design is transmitted to the elevating body.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a vertical sectional view, FIGS. 2 and 3 are a partially sectional top view and a vertical sectional view of the stroke expansion and contraction means, and FIGS. 4 and 5.
The figure is a vertical sectional view of a work station different from that shown in Fig. 1 and shows a different operating state, Fig. 6 is a top view of the support means, Fig. 7 is a side view of the suction nozzle selection device, and Fig. 8 is the same as that shown in Fig. 7. FIG. 9 is a side view of the suction nozzle selection device in a different operating state, similar to FIG. 7, and FIG. 10 is a top view of the vacuum suction means related to FIG. 9. , FIG. 11 is an operation explanatory diagram showing the behavior of the vacuum suction means in each work station in parallel. 52, 52'... Parts, 60... Board, 50...
...Component supply device, 1... Supporting means, 30... Vacuum suction means, 90... Lifting body, 97... Cam, 10
0... Stroke expansion/contraction means, 106... Seesaw lever, 109... Hollow shaft forming the fulcrum of the seesaw lever.

Claims (1)

[Scope of Claims] 1. A support means that rotates intermittently in a fixed direction above a board on which components are to be mounted and a component supply device; a plurality of vacuum suction means supported and always maintained at a height apart from the substrate or the component supply device; provided at least at a location corresponding to the component supply device and a location corresponding to the substrate; A device comprising a plurality of elevating bodies that lower each of the vacuum suction means to approach the target each time it reaches above the target, and a cam that moves the elevating bodies, wherein any elevating body and cam are provided. A stroke extending/contracting means for extending/contracting the operating stroke of the elevating body is arranged between the two, and the stroke extending/contracting means includes a seesaw lever that transmits the displacement of the cam to the elevating body, and a fulcrum of the seesaw lever relative to the seesaw lever itself. , means for moving the seesaw lever along the axial direction thereof.