JPS6153181B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic screw and nut assembly mechanism.

Generally, screws are used in combination with nuts and washers to tighten and connect items when assembling items. Another use is to combine it with a locking nut in advance and then attach it to an item for the purpose of position adjustment, prevention of loosening, etc. This operation is very time-consuming because it requires assembling one screw and one nut at a time, and a device for assembling screws and nuts that is smaller and cheaper than the conventional one has been desired.

Conventionally, a device shown in a perspective view of FIG. 1 has been used as a screw and nut combination device. This device includes a rotary table 2 having a hexagonal hole slightly larger than the outer diameter of a nut 1 on its upper surface, a drive unit 3 that rotates the rotary table 2 intermittently, and a nut that rotates in synchronization with the intermittent rotation of the rotary table 2. a nut supply section 4 that supplies the nut 1; a screw tightening section 6 that has a screw holding mechanism at its tip and moves up and down in synchronization with the rotational movement of the rotary table while rotating to tighten the screw 5 into the nut 1; It is comprised of a screw supply section 7 which supplies screws 5 to the nut 1 and a discharge section 8 which discharges the combined nut 1 and screw 5.

This device requires complicated power transmission because the driving parts, such as the rotational movement and lifting movement of the screw tightening part 6 and the intermittent rotational movement of the rotary table 2, are independent, and each must also perform synchronous movement. This has the disadvantage that it requires a mechanism, making the device large and expensive.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the conventional drawbacks, realize a screw and nut combination mechanism using a single drive shaft, and provide a compact and inexpensive screw and nut combination device.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

2 and 3 are a side sectional view and a plan view taken from the arrow X of the embodiment of the present invention. In this device, a rotating shaft 10, which is connected to a drive unit 9 that supplies counterclockwise rotation at a constant speed and has a disk-shaped tsuba 10' at the bottom, is fixed with an elastic body 11 having a high coefficient of friction along its outer periphery. The disc-shaped rotating body 12 is integrated with a nut 14 via a spacer 13, and performs a constant rotational movement counterclockwise. In addition, the rotating shaft 10
A rotating shaft 1 is connected between the tsuba 10' and the disc-shaped rotating body 12.
The nut holding table 16 is a stepped cylindrical body built in such a way that it can freely rotate with respect to 0, and has a holding groove 15 for the nut 1 along the outer periphery of the major axis. The rotating shaft 10 between
A screw holding table 18 is a disc-shaped body that is incorporated so as to be able to rotate freely against the nut holding groove 15 and has a U-shaped screw holding groove 17 along its outer periphery, and a fixing pin 19 connects the nut holding groove 15 to the screw. The retaining grooves 17 are integrated so that their centers coincide with each other, and the disc-shaped tsuba 10'
A driven movement is performed relative to the rotating shaft 10 by the frictional force between the upper surface and the lower surface of the nut holding table 16 and the frictional force between the upper surface of the disc-shaped rotating body 12 and the lower surface of the screw holding table 18.

However, when the ratchet 21, which is constantly pressed against the nut holding table 16 by the spring 20, engages with the nut holding groove 15, the rotational movement of the nut holding table 16 and the screw holding table 18 is blocked, and the rotational movement of the nut holding table 16 and the screw holding table 18 is prevented. Only the plate-shaped rotating body 12 performs constant rotational motion.

In this state, the screws 5 and nuts 1 are aligned with the screw supply rail 22 and the nut supply rail 23.
are supplied to the screw holding groove 17 and the nut holding groove 15 one by one.

On the other hand, the screw 5 in the position shown in FIG. Clockwise rotational movement is performed by friction with the body 11.

When the rotational movement of the screw 5 starts in this way, the nut 1 is moved around the screw 5 as shown in the detailed views of FIGS. 4a and 4b.
and moves upward along the nut holding groove 15. Nut 1 rises, as shown in Figure 4c,
When released from the nut holding groove 15, the nut 1
rotates together with the screw 5, and the nut 1 is no longer screwed into the screw 5.

Also, a ratchet pin 2 is fixed to the side surface of the disc-shaped tsuba 10' of the rotating shaft 10 that performs constant rotational motion.
5 rotates once and releases the ratchet 21, the screw holding table 18 and nut holding table 16
The nuts 1 and screws 5 that have been moved by the pitch and are aligned with the nut supply rail 23 and the screw supply rail 22 are again supplied to the nut holding groove 15 and the screw holding groove 17. Further, when the nut 1 combined with the screw 5 moves to position B in FIG. 3, it is released from the screw holding groove 17 and discharged onto the tray 26.
Further, by adjusting the dimension l of the nut holding groove 15 of the nut holding table 16 shown in FIG. 4b, it is also possible to change the combined dimensions of the nut 1 with respect to the screw 5.

As explained above, this mechanism uses a single drive shaft to realize a screw and nut combination mechanism that has the function of receiving supplied screws and nuts, the function of combining screws and nuts, and the function of discharging them. It is small and can be provided at low cost.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional screw and nut combination mechanism, Fig. 2 is a side sectional view of an embodiment of the present invention, Fig. 3 is a view taken along arrow a-a' in Fig. 2, and Fig. 4 a. ,b,c
3 is a detailed view of the screw and nut combination in section A of FIG. 3, and FIG. 5 is a view taken along the line b-b' in FIG. 4a. In the figure, 1... Nut, 2... Rotary table, 3... Drive section, 4... Nut supply section, 5... Screw, 6...
Screw tightening part, 7... Screw supply part, 8... Discharge part,
9... Drive unit, 10... Rotating shaft, 10'... Tsuba,
11... Elastic body, 12... Rotating body, 13... Spacer, 14... Nut, 15... Nut holding groove, 16... Nut holding table, 17... Screw holding groove, 18... Screw holding table, 19...Fixing pin, 20...Spring, 21...Ratchet, 2
2... Screw supply rail, 23... Nut supply rail, 24... Holding plate, 25... Ratchet pin,
26...Tray.

Claims (1)

[Scope of Claims] 1. A rotating shaft having a disk-shaped tsuba and connected to a drive source to rotate at a constant speed counterclockwise; and a nut having a shape that can be held so as not to rotate, and the nut being an axis of the rotating shaft. It has a plurality of nut holding grooves arranged at equal pitches on the circumference and is shaped to be able to slide parallel to the center, and is fitted onto the rotating shaft so that the nut is coaxially moved with the rotating shaft by frictional force with the disc-shaped tsuba. A cylindrical nut holding table that performs rotational movement, and a shape that allows the screw to be held such that the axis of the nut supplied to the nut holding groove and the axis of the screw coincide, and the screw rotates with respect to the axis of the screw. a screw holding table having a screw holding groove of a possible shape on the circumference at the same pitch as the nut holding groove, fixed to the upper part of the nut holding table with a pin, and rotating coaxially with the nut holding table; Between the table and the screw holding table, there is a gap slightly wider than the thickness of the nut between the table and the top surface of the nut holding table, and the outer periphery is fixed to the rotating shaft and held on the screw holding table. a disc-shaped rotating body formed of a material with a contactable diameter and a high coefficient of friction so as to easily transmit screw rotational motion; a ratchet for stopping, a ratchet pin mounted on the circumference of the disc-shaped tsuba for releasing the ratchet at regular intervals and giving intermittent rotational motion to the nut holding table and the screw holding table; and a ratchet pin for causing the screw holding groove to stop intermittently. a holding plate for pressing the side surface of the screw held in the screw holding groove against the disc-shaped rotating body and transmitting rotational motion to the screw; a nut supply rail that is installed at a position of the nut holding groove one or several pitches in front of the holding plate and supplies the nuts aligned in the nut holding groove; It consists of a screw supply rail that is installed at a position one to several pitches in front of the screw retaining groove with respect to the plate and supplies screws aligned with the screw retaining groove, and the screw supply rail is configured to supply screws that are aligned with the screw retaining groove so that the screws and nuts can be supplied by natural fall. A screw and nut combination device in which the entire device is tilted with the supply rail and nut supply rail on the upper level.