JPH0536177B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a screw supply positioning device, and more particularly, to a screw supply positioning device that maintains a screw in an accurate screw tightening posture and supplies the screw to a screw tightening position. It is something.

[Prior Art and Problems to be Solved] Fig. 6 shows a screw holding part in a conventional screw tightening device for tightening screws with washers. A flat washer 74 at the stepped portion 101A
This is a method of holding and fixing it horizontally. As is well known, this screw has a constriction formed between it and the shaft portion 72 of the head, and a spring washer 7 is attached to this constriction.
3. A flat washer 74 is inserted and engaged with the shaft portion 72 so as to be freely movable. Therefore, due to the presence of this spring washer 73, the shaft portion 72 of the screw is not perpendicular to the surface of the stepped portion 101A, and the screw tightening bit 14 moving down the axis of the vacuum suction tube 101 is It often happens that the screw cannot be tightened unless it is oriented correctly downwards.

The unstable posture of the screw is especially serious in the case of a so-called stubby screw in which the total length L of the spring is not sufficiently large compared to the diameter D of the flat washer, and the screw tightening bit frequently misdrives in an automatic screw tightening machine. There is a drawback that situations arise.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and includes a pair of chuck grooves 31 formed on the opposing inner surfaces, which are perpendicular to the upper surface 3A. A parallel bar-shaped chuck chute 3; a vacuum suction tube 13 disposed above the chuck chute 3 so as to be movable up and down; a rotating shaft 4 and a guide shaft supporting the chuck chute 3 so as to be able to slide toward or away from each other. 5, a pair of rotating plates 2 which are located on the outside of the chuck chute 3 and through which the rotating shaft 4, the guide shaft 5 and the cam drive shaft 9A are penetrated and supported; , a drive motor M that transmits rotation to the cam drive shaft 9A, a rotary drive device M, 8 including a drive gear 8, and a rotary drive device M, 8 that is mounted on the guide shaft 5 between the chuck chute 3 and the rotary plate 2, and the chuck chute 3 a pair of compression springs 6 that constantly press the chucks 3 toward each other in a direction close to each other; a driven gear 9 and a cylindrical cam 10 that drive the chuck chute 3 toward and away from each other based on the rotation transmitted from the rotary drive device; Cam drive device 9, 10, 11 including cam follower 11
and a stopper 12 that is located above the rotating plate 2 and limits the rotation of the rotating plate 2 for a certain period of time in relation to the operation of the cylindrical cam 10, and the cylindrical cam 10 is in an initial stage. has a cam curve which separates the chuck chute 3 against the compression force of the compression spring 6 in such a way that the screw can slide down, by the rotation of the cam drive based on the rotation transmitted from the rotary drive. The chuck chute 3 has a cam curve that operates so that a screw is chucked in the chuck groove 31 of the chuck chute 3 by the rotation of the cam drive based on the rotation from the rotary drive that is continuously transmitted. The chuck chute 3 has a cam curve that operates to separate the chuck chute 3 in order to transfer the screw being chucked to the vacuum suction tube 13, and furthermore, after the screw transfer is completed, the chuck chute 3 is moved between the vacuum suction tube 13 and the chuck chute 3. The stopper 12 has a continuous cam curve that separates and maintains the distance so that the cylindrical cam 13 can be inserted. The chuck chute 3 operates to release the stop, and accordingly, the chuck chute 3 rotates until it becomes locked with the rotating plate 2 and becomes horizontal.

[Function] The chuck chute 3, which is made up of two rod-shaped members, has a screw that flows in from upstream (with a flat washer and a spring washer).
7, the screw flows to the end of the screw chuck chute 3 and stops. At this time, the chuck chute is closed and the chuck groove 31 is perpendicular to the upper surface of the chuck chute 3 of the screw 7.
The shaft portion of the screw 7 is held in a position perpendicular to the upper surface of the chuck chute 3, regardless of the position of the washer.

Therefore, when tightening a screw, the chuck chute 3 is rotated so that the screw hole to be tightened on the upper surface is arranged parallel to the opening surface, and then the vacuum suction for screw tightening is applied so as not to change the posture of the screw 7. Cylinder 13
If the screw 7 is delivered so that the head of the screw 7 is attracted to the screw 7, and the chuck chute 3 is tightened with the chuck chute 3 separated, the axis of the screw 7 will be parallel to the screw hole, and the screw 7 will be screwed into the screw hole successfully.

[Embodiment] An embodiment of the present invention will be described with reference to FIGS. 1 to 4.

Two rectangular prism-shaped members are arranged in parallel with an interval slightly larger than the screw diameter to form a fixed chute 1, 1, and the screw 7 with a washer slides and falls through the gap between these two members. .

Continuing from the fixed chute 1, 1, two members of the same shape extend parallel to the fixed chute 1, 1,
Form chuck shoots 3,3. Chuck grooves 31, 31 each having an isosceles triangular cross section are formed at the ends of the opposing surfaces of the chuck chutes 3, so as to extend perpendicularly to the upper surface 3A of the chuck chutes 3. A stopper 32 in the form of a rod-shaped projection is provided at the end of the chuck groove 31 and protrudes from one chuck chute 3 near the chuck chute 3 to the opposite chuck chute 3.

As shown in FIG. 3, the chuck grooves 31, 31 sandwich the shaft portion 72 of the screw 7 when the chuck chute 3, 3 are close to each other, and the axis of the screw is parallel to the inner surface of the chuck groove 31, that is, the chuck chute is parallel to the inner surface of the chuck groove 31. perpendicular to the upper surface 3A of.

The two parallel chucks 3, 3 are supported by a pivot shaft 4 and a guide shaft 5 passing through them so as to be slidable toward or away from each other.

Chuck shoots 3, 3 of the rotation shaft 4 and the guide shaft 5
Two rotating plates 2, 2 parallel to each other are provided on the outer side of the rotating shaft 4 so as to be rotatable about a rotating shaft 4. A driving gear 8 is fixed to the outer side of the rotating plate 2 of the rotating shaft 4, and furthermore, a driving means capable of forward and reverse rotation, such as a driving motor M, is directly connected to the outer shaft end. .

A compression spring 6 is disposed on the guide shaft 5 located between the chuck chute 3 and the rotary plate 2, and is used to constantly press the chuck chute 3 toward each other.

In addition to the above-mentioned rotation shaft 4 and guide shaft 5, another cam drive shaft 9A rotatably passes through the rotation plates 2, 2, and two cam drive shafts with a symmetrical shape are located in the center of the rotation plates 2, 2. The cylindrical cams 10, 10 of the respective cam surfaces 10A
They are fixed coaxially to the cam drive shaft 9A, back to back, so as to face the inner surface of the rotating plate 2. A driven gear 9 is fixed to the outer side of the rotating plate 2 at the end of the shaft so as to mesh with the driving gear 8.

In addition, the cam surfaces 10A of the cylindrical cams 10, 10,
Cam followers 11, 11 engaged with 10A are rotatably mounted on chuck chutes 3, 3, respectively.

In particular, this cylindrical cam 10 resists the compressive force of the compression spring 6 in the initial stage and the chuck chute 3
The chuck chute 3 has a cam curve that separates the screws so that they can slide and fall, and the chuck chute 3 is screwed into the chuck groove 31 of the chuck chute 3 by rotation of the cam drive based on the rotation transmitted from the rotary drive. A vacuum suction cylinder 13, which will be described later, has a cam curve that operates as shown in FIG.
The chuck chute 3 has a cam curve that operates to separate the chuck chute 3 in order to transfer the screw to the chuck chute 3.
cam curves that separate and maintain the vacuum suction tube 13 so that the vacuum suction tube 13 can be inserted therebetween. Incidentally, the cam curve of the cylindrical cam 10 of this embodiment is shown in FIG. The forward and reverse rotation of this cylindrical cam 10 is restricted to a range of 0 degrees to 230 degrees, for example.

A stopper 12 that prevents the rotating plate 2 from rotating upward from the state shown in FIG. 1 is provided so as to come into contact with the upper end surface of the rotating plate 2.

Further, stoppers 15 and 16 for forcibly stopping the clockwise and counterclockwise rotations of the rotating plate 2, respectively, are provided at appropriate positions.

Of the above-mentioned devices, the drive motor M, the drive gear 8, and the driven gear 9 are elements that rotate the rotation plate 2, so they will be referred to as a rotation drive device if an overall expression is required. In addition, a driven gear 9, a cylindrical cam 1
0 and cam follower 11 will be referred to as a cam drive if overall representation is required.

When the device shown in FIG. 1 is viewed from the front on the side where the chuck groove 31 of the chuck chute 3 is provided, except for the drive motor M on the right side, the drive gear 8, the driven gear 9 and the stopper 12 on the left side, everything else is left and right. Each member is provided symmetrically.

On the other hand, in Fig. 2, chuck shoot 3,
When the chuck chute 3 is rotated and stopped to the dotted line position shown in the figure by the cooperative operation of the rotary drive device and the cam drive device, the vacuum suction tube 13 is vertically disposed at a portion facing the chuck groove 31 of the chuck chute 3, 3.

As shown in FIG. 4, for example, this vacuum suction cylinder 13 has a suction part 13A at its lower end that suctions the head 71 of the screw 7, and a screw tightening bit is disposed inside the suction part 13A.

Next, the operation of this embodiment will be explained with reference to FIGS. 1 and 5.

(1) The screw 7 is fed from a source (not shown) above the fixed chute 1 and slides down there, and the sliding fall of the screw 7 is stopped at the stopper 32 at the lower end of the chuck chute 3, 3. Thereafter, when the drive motor M rotates clockwise (forward rotation), the drive gear 8 also rotates clockwise, and the driven gear 9 and the cylindrical cam 1 follow.
0 rotates counterclockwise. At this time, the cylindrical cam 10 begins to move from the 0° position of the cam curve shown in FIG.
operates to narrow the gap by the pressing force of the compression springs 6, 6. At the 30° position of the cam curve, the chute 3 closes and checks the shaft 72 of the screw 7 (see Figure 3).

(2) The stopper 12 is removed from the rotary plate 2 at an arbitrary angle while the cylindrical cam 10 rotates up to 80 degrees as shown in the dotted line position from the solid line position in FIG. When the 80° position is reached, the cam follower 11 hits the protrusion of the cam curve at this position, and the cam 10 can no longer rotate, and the relative rotation between the drive gear 8 and the driven gear 9 stops. (locked state),
Both act just like a single rigid lever, causing the rotary plate 2 to rotate clockwise and the stopper 1 to rotate.
Stop when reaching 5. This stop position is the position indicated by the dashed line where the chuck shoots 3, 3 are approximately horizontal. This position is on a plane parallel to the screwing surface of the object to be screwed.

(3) Next, due to the strong stopping resistance by the stopper 15, the cam follower 11, whose relative movement had been stopped by the protrusion at the 80° position of the cylindrical cam 10, moves relative to the cylindrical cam 10. At first, it rides on this protrusion, and the chuck chute 3, 3 opens between 80° and 95° of the cam curve.

Note that the head 71 of the screw 7 gripped by the chuck chute 3 at a position of 80° on the cam curve.
As shown in FIG. 4, the screw 7 is attracted to the suction portion 13A of the vacuum suction cylinder 13, and the screw 7 is moved in response to the opening operation of the chuck chute 3, 3 due to the displacement according to the cam surface of the follower 11. Complete the delivery to. Thereafter, the chuck shoots 3, 3 are closed again by the pressing force of the compression springs 6, 6 at the position of the cam curve 110°.

(4) Since the drive motor M continues to rotate in the forward direction thereafter, the cylindrical cam 10 rotates via the drive gear 8 and the driven gear 9. When the cam follower 11 comes to the 130° position along the cam curve of the cylindrical cam, the rotation of the rotating plate 2 is already inhibited by the stopper 15, so the cam follower 11 moves forward. It comes to ride on the protrusion of the cylindrical cam 10. And check shot 3,3
The chuck groove 31 is widened to a width sufficiently spaced from the outer diameter D of the vacuum suction tube 13 at the cam curve 200° position (see FIG. 4). Thereafter, the screw tightening bit 14 is lowered together with the vacuum suction tube 13, and the screw 7 is directly screwed onto the object to be screwed.

(5) During this screw tightening operation, the cam follower 11 falls into the recess shown by A at the 230° position of the cam curve.

After this, the drive motor M is controlled to reverse (control circuit not shown);
This time, looking at the direction of the drive gear 8 from the motor M, it starts rotating counterclockwise.

During reverse rotation, the cam follower 11 moves along the cam curve A
Since it has fallen into the recess shown by , the relative movement with the cylindrical cam 10 is stopped due to the resistance (locked state), and the driving gear 8 and the driven gear 9 are
The rotary plate 2 is rotated counterclockwise by the action of the rigid lever of the book and returned to its original position where it is stopped by the stopper 16. At this point, the stopper 12 is activated again and rotated to the position shown in solid line in FIG. 1, thereby blocking the rotational movement of the rotary plate 2.

Since the drive motor M continues to rotate under the strong blocking condition by the stopper 16, the cam follower 1
1 escapes from the recess A of the cam curve and becomes a cylindrical cam 10.
The relative rotational state with the chute is restored, the chuck chute 3, 3 closes at the 130° position by tracing the cam curve in the opposite direction to the previous time, and returns to the 0° position after briefly opening at around 110° to 80°. . The opening of the chuck shoots 3, 3 at this 0° position is determined by the lift h at that point, which is, of course, a suitable dimension for waiting for the screw 7 to flow in.

Note that the protruding portion of the cam curve of 80° to 110° can also be omitted. In this case, the screw delivery is
Performed at 130° position.

[Effects] According to the present invention, since the shaft portion of the screw is held by the chuck groove of the chuck chute to determine its position, the position of the screw is coaxial with respect to the screw tightening bit regardless of the position of the washer. It is stable in position and allows for accurate screw tightening. Gravity is used to feed screws, and the chuck chute opens and closes and tilts (rotates) using a single drive means. Because of this, less energy is required to operate the device, and furthermore, after the screw is transferred to the vacuum suction tube 13, the chuck chute 3, 3 is displaced in the axial direction of the rotating shaft 4 while remaining at the same position in the rotation direction. , interference with the vacuum suction tube 13 during the subsequent screw tightening operation can be avoided, and the screw tightening speed can be increased.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a side view of FIG. 5 is an enlarged cross-sectional view of the main part showing the delivery state of the screw, and FIG. 5 is a cam curve diagram of the cylindrical cam.
FIG. 6 is a side sectional view showing conventional screw tightening. 2...Rotating plate, 3...Chuck shoot, 31
...Chuck groove, 4...Rotating shaft, 5...Guide shaft,
6... Compression spring, 7... Screw, 8... Drive gear,
9... Driven gear, 9A... Cam drive shaft, 10...
Cylindrical cam, 11...cam follower. 12...Stopper, 13...Vacuum suction tube, M...Drive motor.

Claims (1)

[Scope of Claims] 1. A pair of parallel rod-shaped chucks 3, each having a chuck groove 31 orthogonal to the upper surface 3A formed on the opposing inner surface, and a chuck chute 3 disposed above the chucks 3 so as to be vertically movable. a vacuum suction cylinder 13; a rotating shaft 4 and a guide shaft 5 that slidably support the chuck chute 3 in a direction toward or away from each other; 5 and a pair of rotating plates 2 through which the cam drive shaft 9A is penetrated and supported, a drive motor M that rotates the rotation shaft 4 and transmits rotation to the cam drive shaft 9A, and a drive gear 8. a pair of compression springs 6 mounted on the guide shaft 5 between the chuck chute 3 and the rotary plate 2 and constantly pressing the chuck chute 3 toward each other; and the rotary drive. A cam drive device 9, 10, 11 that includes a driven gear 9, a cylindrical cam 10, and a cam follower 11 that drives the chuck chute 3 toward and away from each other based on the rotation transmitted from the device.
and a stopper 12 that is located above the rotating plate 2 and limits the rotation of the rotating plate 2 for a certain period of time in relation to the operation of the cylindrical cam 10, and the cylindrical cam 10 is in an initial stage. has a cam curve which separates the chuck chute 3 against the compression force of the compression spring 6 in such a way that the screw can slide down, by the rotation of the cam drive based on the rotation transmitted from the rotary drive. The chuck chute 3 has a cam curve that operates so that a screw is chucked in the chuck groove 31 of the chuck chute 3 by the rotation of the cam drive based on the rotation from the rotary drive that is continuously transmitted. The chuck chute 3 has a cam curve that operates to separate the chuck chute 3 in order to transfer the screw being chucked to the vacuum suction tube 13, and furthermore, after the screw transfer is completed, the chuck chute 3 is moved between the vacuum suction tube 13 and the chuck chute 3. The stopper 12 has a continuous cam curve that separates and maintains the distance so that the cylindrical cam 13 can be inserted. A screw supply posture determining device characterized in that the chuck chute 3 operates to release the stop, and accordingly the chuck chute 3 rotates until it becomes in a locked state with the rotating plate 2 and becomes in a horizontal state.