JPS6322020Y2 - - 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) Prior Art In manufacturing assembly lines that perform large-scale production, manual screw tightening work is gradually receding, and automated screw tightening machines are replacing it. Such screw-driving machines can be roughly divided into those that move the driver unit vertically and those that move the driver unit horizontally. Now, among the things that move in the vertical direction, there are things of the type described below. That is, a movable screw holder that can change its direction downward is provided opposite to the outlet of the chute that feeds out the screw, and above the screw holder is a vacuum suction type driver unit in which the driver bit is wrapped in a sheath-shaped suction pipe. The screwdriver unit is moved downwards, pushing aside the screw receiver while sucking the screw into the suction pipe, and performs the tightening operation below the screw receiver. For example, JP-A-55-
This is what is described in No. 96277. The advantage of this type is that it has a simple configuration and is easy to manufacture, but the presence of the screw holder can get in the way when centering the driver unit or trying to feed a screw with the chute. Ta.

(c) Purpose of the invention The present invention provides a screw tightening device in which a movable screw holder is placed in front of a vacuum suction driver unit, and the screw holder can be easily moved to a position where it does not interfere with various adjustments. The purpose is to

(d) Structure of the invention In this invention, a support piece is suspended opposite to the inclined chute, and a screw receiver is installed at the lower end of this support piece in two positions: a normal position where it protrudes toward the chute side, and an inverted position where it goes around to the opposite side. It is pivoted so as to be movable in a vertical plane so that it can take two positions, and a toggle spring that biases the spring support toward one of the two positions is hung between the support piece and the spring support, and the spring is activated when necessary. The bridge can be turned around to make adjustments etc. easier.

(e) Embodiment In the figure, 1 is a frame constructed by combining steel materials in a substantially U-shape, and 2 is a guide bar supported perpendicularly to the frame 1. Two guide bars 2 are arranged in parallel in a direction perpendicular to the paper surface. An elevator 3 is attached to the guide bar 2, and is raised and lowered by an air cylinder 4 vertically supported on the upper part of the frame 1.
Reference numeral 5 denotes a stopper fixed to the guide bar 2 to determine the lowering limit of the elevator 3. Reference numeral 6 designates a latch pivotally supported on the side wall of the frame 1. This latch 6
is biased by a spring 7 to project its upper end toward the elevator 3, allowing the elevator 3 to rise, but when descending, the flange 9 of the connecting body 8 connecting the rod of the air cylinder 4 and the elevator 3 engages and stops the elevator 3 in place. this is,
This is to prevent the elevator 3 from falling naturally due to a drop in air pressure within the air cylinder 4.
During normal operation, the lock release cylinder 10 provided in the elevator 3 pushes it out of the engaged position each time it descends. That is, the unlocking cylinder 10 has a piston 11 that moves horizontally.
A rod 12 integral with the latch 6 is made to protrude toward the latch 6. The piston 11 is normally retracted deep into the cylinder 10 by the spring 13, but when compressed air is introduced from the hose 14, it moves forward and the rod 12 pushes the latch 6. 15 is a commercially available electric driver unit supported by the elevator 3. The driver unit 15 is installed with the driver bit 16 facing directly below. A suction pipe 17 enclosing the driver bit 16 passes through a bearing 18 in the lower part of the frame 1.

19 is an inclined chute connected to the lower part of the frame 1. The inclined chute 19 slides down the screws 20 arranged in a row, the lower end of the row is received by a separator 21, and the screws are ejected one by one in accordance with the work tact.
The structure of the separator 21 is shown in FIG. This is a U-shaped oscillating body 23 that oscillates around a shaft 22, with closing pawls 24 and 25 facing each other being attached at different positions to the free end of the U-shaped oscillating body 23.
Separate only the first one from the column and send it out. This type of mechanism has been well known for a long time, as seen, for example, in Japanese Patent Publication No. 29-4900.

26 is frame 1 facing chute 19.
This is a support piece that hangs down from the base. A screw receiver 27 is pivotally supported at the lower end of the support piece 26 by a shaft 28 so as to be rotatable in a vertical plane. The screw receiver 27 has a bifurcated proximal end, and is pivotally supported so as to catch the support piece 26 from the outside.In addition to the normal position shown in FIG. It is also possible to come to the inverted position shown in FIG. Support piece 26
A toggle spring 29 made of a tension coil spring is stretched between the screw receiver 27 and the screw receiver 27, and the screw receiver 27 is biased toward the normal position or the reversed position with the consideration point as a boundary. A bolt 30 is screwed into the frame 1 and serves as a stopper for the screw receiver 27 in the normal position. A receiving groove 31 is formed in the free end of the screw receiver 27, and the receiving groove 31 terminates directly below the driver unit 15. Screw receiver 27 up to the end point of receiver groove 31
The upper surface of the chute 19 is a sloped surface that is continuous with the slope of the chute 19.

Next, the action will be explained. FIG. 1 shows the state during the work standby period, in which the driver unit 15 is waiting above. During this period, one screw 20 is released from the chute 19, and the screw receiver 27 receives and holds it. A lowering command is then issued, and as shown in FIG.
also operates to lower elevator 3. The release cylinder 10 only needs to be activated until the flange 9 of the coupling body 8 reaches a level below the upper end of the latch 6. When the elevator 3 further descends from the state shown in FIG. 2, the driver unit 15 sucks the screw 20 into the suction pipe 17. Thereafter, the driver unit 15 descends while pushing the screw receiver 27 downward with the suction pipe 17 (lower part of Fig. 3).
The workpiece is tightened with the screw 20 on the lower workpiece and then ascends. As shown in the upper part of FIG. 3, the elevator 3 moves up while grazing the latch 6 with the coupling body 8 and returns to the standby position. When the pneumatic pressure drops due to a failure in the pneumatic system, the latch 6 performs its original function to prevent the elevator 3 from descending, as shown in FIG.

If the screw receiver 27 gets in the way when centering the driver unit 15, etc., flip the screw receiver 27 up to the opposite side of the support piece 26 as shown in FIG.
The same thing is done when testing the feeding function of the chute 19. At this time, chute the box that receives the screws 20.
Leave it at exit 9. In this way, the screws 20 can be continuously fed out one after another.

(f) Effects of the invention According to the invention, by flipping up the screw receiver pivoted on the support piece to the opposite side of the chute, various adjustments can be made without having to worry about the screw receiver.
This further improves usability.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, and Figs.
The figure is a partially cutaway side view explaining the overall structure and the screw tightening operation, Figure 4 is a partial side view explaining the action of the latch, and Figure 5 is a diagram explaining the structure of the screw escapement mechanism. , FIG. 6 is a partial side view illustrating the reversing operation of the screw receiver. 20...screw, 19...chute, 27...screw receiver, 15...driver unit, 17...suction pipe, 26...support piece, 29...toggle spring.

Claims (1)

[Claims for Utility Model Registration] A chute that feeds out screws one by one, a movable screw receiver that receives the screws at the outlet of the chute, a movable screw receiver that approaches the screw receiver from above and sucks up the screws into a suction pipe, Furthermore, a vacuum suction type driver unit is provided which advances downward and performs tightening work while forcibly pushing away the screw receiver, and a supporting piece is provided hanging down to face the chute, and the lower end of this supporting piece is provided with the above-mentioned The screw receiver is rotatably supported in a vertical plane so that it can take both a normal position in which it protrudes toward the chute and an inverted position in which it goes around to the opposite side of the support piece, and the support piece and the screw receiver are A screw tightening device in which a toggle spring that biases the screw receiver toward either the normal or reversed position is stretched between the screw receivers.