JPH0243626Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a screw tightening machine used in an automatic assembly line.

(b) Conventional technology On manufacturing assembly lines that carry out large-scale production, manual screw tightening work is gradually receding, and automated screw tightening machines are replacing it. In such an automatic screw tightening machine, for example,
A Y-shaped chuck in which a pit guide hole and a screw supply hole are diagonally crossed, as shown in Japanese Patent No. 14480, has been commonly used in the past. However, recently, combinations of vacuum suction type driver units and open screw receivers have become more common. This is because the screw receiver is easier to manufacture than the Y-shaped chuck, and it is easier to accommodate an increase in the types of screws. The supply of screws to the screw receiver is described in Japanese Unexamined Patent Application Publication No. 1987-
As seen in Publication No. 96277, an inclined chute is normally used, but in such a chute,
The problem was that it was not possible to supply screws with long necks. Therefore, a method of supplying screws one by one using compressed air was proposed. Unexamined Japanese Patent Publication 1987-
An example is the device described in Publication No. 75787. This device employs a structure in which a screw is once received in a chute having a slit, the screw is pushed by a cylinder-driven pusher into a catcher provided in line with the chute, and the screw is delivered from this catcher to a driver unit.

(c) Problems to be solved by the invention The invention combines a vacuum suction type driver unit and an open type screw receiver, and is configured to supply screws using compressed air. The object of the present invention is to provide a device that simplifies the mechanism leading to the delivery of this to the driver unit, and that can obtain the driving force of the mechanism from the movement of the driver unit itself.

(d) Means for Solving the Problems In the present invention, the vacuum suction type driver unit is supported by an elevator and reciprocates in the vertical direction. A screw receiver supported by a horizontally rotating revolving body reciprocates between the screw supply point for the driver unit and the exit of the screw feeding tube. The screw receiver is tiltable in the advancing direction of the driver unit and does not hinder the advance of the driver unit. A toggle spring exerts a force on the rotating body to maintain the screw receiver in each end position of its reciprocating stroke. Motion is provided to the rotating structure by first and second cam followers, both of which are operated by cams attached to the elevator.

(e) Effect When the rotating body is maintained in a state where the screw receiver is located on the reciprocating path of the driver unit (first angle state), the driver unit descends. When the tip of the driver unit sucks in the screw held in the screw holder and tries to push the screw holder away and continue descending, the cam on the elevator side gives movement to the first cam follower, and the first cam follower Motion is applied to the rotating body, and the rotating body passes through a point of consideration in the toggle mechanism to a state in which the screw receiver is aligned with the outlet of the feed tube (second angular state). The screw receiver now receives the screw from the feed tube. When the driver unit that has been tightened rises and its tip reaches above the level of the screw receiver, the second cam follower is given movement by the cam on the elevator side and moves the revolving structure.
The rotating body returns from the second angular state to the first angular state.

(F) Embodiment In the figure, reference numeral 1 indicates a frame constructed by combining steel materials in a substantially U-shape, and reference numerals 2 and 2 indicate a pair of guide bars supported perpendicularly to the frame 1. An elevator 3 is supported by the guide bar 2, and is raised and lowered by an air cylinder 4 vertically attached to the upper part of the frame 1. 5 is a commercially available vacuum suction type electric driver unit supported by the elevator 3 with its axis perpendicular to the elevator 3. The driver bit 6 and the suction pipe 7 surrounding it face downward and pass through a bearing 8 attached to the lower part of the frame 1.

Reference numeral 9 denotes a feeding tube supported vertically on the side surface of the frame 1. The feeding tube 9 feeds the screws 10 one by one with compressed air and discharges the compressed air from the downward outlet pipe 11. Reference numeral 12 designates a screw receiver that carries the screw 10 from the outlet pipe 11 to the screw supply point for the driver unit 5. The screw supply point is located in the reciprocating path of the driver unit 5 at a position slightly lower than the lower end of the suction pipe 7 during the standby period (FIGS. 1 and 2). The screw receiver 12 is attached to one end of a revolving body 14 that rotates horizontally about a shaft 13.
Mounting is performed by pivoting the arm portion 15 extending upward from the screw receiver 12 to the revolving body 14 via a horizontal shaft 16, and the screw receiver 12 is made swingable in a vertical plane extending radially from the shaft 13. ing. Screw receiver 12
A receiving groove 17 facing outward when viewed from the center of rotation, that is, facing in the centrifugal direction is formed in. A compression coil spring 18 is inserted between the screw receiver 12 and the revolving body 14 to bias the screw receiver 12 so that it swings in the centrifugal direction and presses it against the stopper 19. The movement of the rotating body 14 is 1
This is done by a pair of push rods 20, 21 and a toggle spring 22. The push rods 20 and 21 are supported by a holder 23 fixed to the lower surface of the frame 1, and are horizontally slidable. The push rods 20 and 21 abut against the side surface of the rotating body 14. As seen in FIG. 6, the area is symmetrical about the axis 13,
The push rod 20 is on the side closer to the screw receiver 12, and the push rod 21 is on the opposite side. The holder 23 has a stopper 2 that stops the rotating body 14 when the screw receiver 12 is at the screw supply point (the first angle state of the rotating body 14).
4, and the screw receiver 12 is the outlet pipe 11 of the feeding tube 9.
(second angular state of the rotating body 14)
A stopper 25 is provided to stop the rotating body 14 at a position, and a torque spring (tension coil spring) 22 stretched between the rotating body 14 and the holder 23 stabilizes the rotating body 14 in either of these two positions. 27 and 28 are first and second cam followers that are combined with the push rods 20 and 21. The cam followers 27 and 28 are lever-like members having a roller 29 at the upper end and a hammer head 30 at the lower end, and are pivotally supported by a shaft 32 on a bracket 31 protruding from the frame 1, and are swingable in a vertical plane. There is. push rod 20,2
1 are each biased towards the hammerhead 30 by a spring 33. Also, on the side of the elevator 3, cams 34 and 3 for operating the cam followers 27 and 28 are provided.
5 is fixed, and the spring 26 shown in FIGS.
The cam followers 27 and 28 are urged in the direction of contacting the cams 34 and 35.

36 is a guide plate fixed to the lower part of the frame 1. As seen in FIGS. 6 and 7, the guide plate 36 is arranged along the movement path of the screw receiver 12 so as to surround the outside thereof. A movable plate 37 is disposed along the reciprocating path of the driver unit 5 so as to be continuous with the guide plate 36, and is pivoted to the frame 1 by a shaft 38 so as to be rotatable in a vertical plane.
As a result, it is energized in the direction of contacting the suction pipe 7. 40 is a support piece formed on the guide plate 36, and when the screw receiver 12 comes under the feeding tube 9,
It goes around under the screw receiver 12.

Next, the action will be explained. Figures 1, 2, and 6 show states in which screw tightening work is about to start. Screw receiver 1
2 holds the screw 10 and is located directly below the driver unit 5. This state (the first angular state of the rotating body 14) is kept stable by the toggle spring 22. The situation of the cam followers 27 and 28 is as shown in FIG. 4, with the second cam follower 28 pushing the push rod 21 and the first cam follower 27 leaving the push rod 20 free. Here, when the driver unit 5 is lowered, the suction pipe 7 is moved to the movable plate 3.
Push aside 7 and approach the screw 10, and suck up the screw 10 as shown in FIG. The suction pipe 7 still displaces the screw receiver 12 and continues to descend toward the workpiece. The cams 34 and 35 also descend along with the elevator 3, and first the second cam follower 28 comes off the crest of the cam 35 and releases the push rod 21, then the suction pipe 7 finishes sucking up the screw 10, and then the screw The first cam follower 27, which is about to descend below the level of the receiver 12, rides on the peak of the cam 34 and pushes the push rod 20. This is the situation shown in FIG. 5, where the rotating body 14 rapidly moves past the point of consideration of the toggle mechanism and comes to the position (second angular state) shown in FIG. 7. The elevator 3 still descends and the first cam follower 27 comes off the cam 34, but
Since the toggle spring 22 is acting, the state of the rotating structure 14 does not change. Here, as shown in FIG. 8, the screw 10 is discharged from the feeding tube 9 and received by the screw receiver 12. At this time, the screw 10 collides with the screw receiver 12 at high speed, and the compressed air flow also acts to try to push it downward, but since the support piece 40 supports it from below, the screw receiver 12 rotates. There is no chance of the screw 10 falling off. The screw receiver 12 waits for a while while holding the screw 10. During this time, the driver unit 5 finishes tightening the screws on the workpiece and moves on to the upward stroke. When the lower end of the suction pipe 7 rises above the level of the screw receiver 12, the cam 35 kicks the second cam follower 28, and the push rod 21 hits the rotating body 14. The rotating body 14 again passes the point of consideration of the toggle mechanism and quickly returns towards the screw feed point. At this time, centrifugal force is applied to the screw 10, but the
As shown in the figure, since the guide plate 36 and the movable plate 37 guard the outside, the screw 10 does not protrude from the screw receiver 12. The device thus returns to its initial state and the above operations are repeated.

(g) Effects of the invention In this invention, a single screw receiver reciprocates between the screw feeding tube and the driver unit to transfer the screws, so the configuration is simplified.
Easy to manufacture. Furthermore, since the movement of the screw receiver is brought about by the movement of the driver unit, there is no need to provide a separate power source or a control section for that power source, and the configuration can be simplified in this respect as well.

[Brief explanation of the drawing]

The figure shows one embodiment of the device according to the invention, the first
The figure is a partially sectional front view, Figure 2 is a partially sectional side view,
Figure 3 is a partially sectional side view in a different state from Figure 2;
Figures 4 and 5 are explanatory diagrams of the operation of the cam and cam follower that change the position of the screw receiver, Figures 6 and 7 are bottom views of different operating states, and Figure 8 is a vertical view explaining the function of the support piece. 9 is a horizontal sectional view illustrating the function of the guide plate. 3... Elevator, 5... Driver unit, 9... Feeding tube, 10... Screw, 12...
...screw receiver, 14... revolving body, 22... toggle spring, 34, 35... cam, 27... first cam follower, 28... second cam follower.

Claims (1)

[Scope of claims for utility model registration] (1) A screw tightening device with the following configuration. (a) A vacuum suction type driver unit that is supported by an elevator and reciprocates vertically. (b) A feeding tube that discharges screws one by one using compressed air. (c) Supported by a revolving structure that rotates horizontally. , a screw receiver that reciprocates between the screw supply point on the reciprocating path of the driver unit and the outlet of the feeding tube, and is tiltably supported to allow the driver unit to advance; (d) the revolving body; a first angular state in which the screw receiver is located on the reciprocating path of the driver unit;
or (e) a toggle spring for selectively maintaining a second angular position in which the threaded receiver is aligned with the outlet of the feed tube; a first angular state for moving the rotating body in response to the movement of the rotating body descending below the level of the receiver, and for transitioning the rotating body from the first angular state to the second angular state;
The cam follower (f) is also operated by a cam attached to the elevator, and in response to the movement of the tip of the driver unit rising above the level of the screw receiver, it gives movement to the rotating body and moves the rotating body to the second position. a second cam follower for transitioning from an angular state to a first angular state;