JPS63200930A - Automatic nut fastening device - Google Patents

Abstract

PURPOSE:To automatically fasten nut by arranging a motor on the upper surface of a frame while a guide for a vertical shaft directly coupled to the motor is arranged in the lower section of the frame, and by transmitting the torque of the motor to a hexagonal aperture socket below the shaft through the intermediary of a groove in the shaft upper section, a pin and a resilient means below the shaft. CONSTITUTION:A motor 1 is started, the torque thereof being transmitted to a hexagonal space 50 in a socket 9 through a groove 5 and a resilient member 8 so as to absorb an angular shift, a center-axial shift, a vertical shift and the like between a hexagonal nut and a stud bolt 18. Further, a magnet 10 disposed in the MG chamber 58 absorbs several shifts of the nut 17 and absorbs the latter to prevent the same from dropping until the nut abuts against the bolt 18. Further, the fastening torque of the nut 17 is surely transmitted, and after fastening of the nut, the hexagonal chamber 50 is automatically relieved upward. Thus, it is possible to surely fasten the nut even though a shift is large.

Description

[Detailed description of the invention] [Field of practical application] The present invention relates to a device that automatically tightens a nut onto a screw protruding from a mechanical unit, and in particular, a device that engages a screw thread with a self-aligning action. It is.

[Conventional technology]

To fasten a hexagonal nut to a threaded part such as a stud bolt,
Insert the hexagonal nut into the manual wrench socket to rotate the wrench. If this is done, the threads of the hexagonal nut will slide along the threads of the stud bolt and rotate, resulting in the phenomenon of being fastened.

The axial center of the hexagonal nut and the axial center of the threaded part are not necessarily aligned, and the corners W or cores are misaligned, making it difficult to fasten them. However, in the case of manual operation, the hexagonal nuts are smoothly and sequentially fastened to the threaded part by carefully handling the misalignment using the hands of a skilled worker. As an application of these, JP-A-57-1670 discloses a more flexible device as shown in FIG.
0, and the socket 4 is provided so as to be freely buffered via a spring 21. In this way, the socket 64
is given many degrees of freedom in the horizontal direction. This makes it easier to fasten a hexagonal nut to a threaded part of a stud bolt, even if there is some misalignment.

[Problem that the invention seeks to solve]

As for automatically tightening hexagonal nuts, the method that combines a spring and a universal screw as described above cannot be used if the threaded part is only slightly dislocated with respect to the hexagonal nut core. can.

However, it has the drawback of not being able to deal with angular misalignment.

The present invention is intended to be able to reliably fasten a hexagonal nut to a threaded portion of a loading bolt even if the horizontal and angular deviations are large, and the hexagonal nut can be easily fastened even if there is a large deviation. It is to provide mounting.

Measures to address problem C] In order to achieve the objectives stated above, the following measures will be taken.

A motor is provided on the top surface of the frame, a guide is provided on the bottom surface of the frame vertically through which the shaft passes vertically, and a hexagonal hole socket in which a magnet is embedded via an elastic body is provided below the shaft, and the shaft and motor are connected to each other. It is characterized by a direct connection via a transmission shaft, and a pin provided at the top of the shaft.

In these configurations, the transmission force of the motor is transmitted to the hexagonal hole of the socket via the pin, groove, and elastic body, so angular misalignment, center misalignment, etc. are absorbed by the sliding portion of the pin and the relief of the elastic body, and the hexagonal The torque to tighten the NAND is steadily transmitted, and after tightening, the hexagonal hole automatically escapes upward by the cam mechanism of the pin and tile. Just by rotating the hexagonal nand, bring the hexagonal nand into contact with the threaded part of the other bolt and tighten it! After tying, the socket can automatically escape upwards.

〔Example〕

The present invention will be explained in detail based on FIGS. 1 to 4. The frame 2 has an upper plate 11 and a lower plate 12 fixed vertically via a bracket 16, and a hollow guide 7 is provided vertically on the lower plate 12. The motor 1 is fixed to the upper surface of the clay plate 11 and connected to the transmission shaft 6, the outer surface of the cylindrical shaft 6 having a hollow surface is in contact with the hollow surface of the guide 7 described above, and the hollow surface of the shaft 6 is connected to the transmission shaft 3. The transmission shaft 3 is fixedly provided with a penetrating pin 4 as shown in FIG. 5 will be provided.

This #5 shall open in the direction crossing the center of the shaft 6, and the pin 4 shall be in contact with some surface of this groove 5.
It is provided so that it can be inserted.

That is, the upper interior 62 of both ends of the pin 4 is provided on the upper surface 60 of this groove 5.
Or, the lower interior etc. can touch and slide.
There is one pair of places where 5 and pin 4 touch, and by making contact at two places, the weight of the other components @6 is balanced and supported.

The upper surface 30 and lower surface 31 of the groove 5 are spirally curved with respect to the shaft 6, forming a kind of cam mechanism.

A top plate 14 is fixed to the lower end of the shaft 6, and the elastic body 8
It is connected to the bottom plate 16 via.

This elastic body 8 is made of rubber, synthetic resin, spring, composite material, etc., so that it can withstand the weight of the socket 9 and is sufficient to rotate the socket 9. This allows the combined force of both the vertical force, which is the weight of the socket, etc., and the torque, to be applied to the tightening of the hexagonal nut 17. It is also possible to use a plate spring to withstand the vertical force and torque, or to combine a metal band into a rubber material.

That is, even if a misalignment and an angular misalignment of the center occur between the upper surface plate 14 and the lower surface plate 15, it is only necessary to be able to quickly and reliably return to the origin. As a result, the core of the socket 9 provided through the plate 16 of the lower plate 15 can be freely moved in the vertical and horizontal directions.

A recess 61 is provided in the lower surface of the socket 9 in an upward direction. This recessed portion 61 is defined by the MG chamber 58° and the escape chamber 59° from above. Four chambers, a hexagonal chamber 50 and a tapered chamber 51, are provided, and the magnet 10 is inserted into the MG chamber 58 and fixed, and the surface 56 around the hexagonal chamber 50 abuts the corner 60 of the hexagonal nut 17 to tighten the hexagonal nut 17.
to rotate. The hexagonal nut 17 is connected to the tapered chamber 5
When the magnet 1 is inserted into the hexagonal chamber 50 in contact with the surface of the magnet 1
Since ° is installed in the socket 9 OMG chamber 58,
The hexagonal nuts that are attracted are prevented from falling.

B in FIG. 6 is slightly thicker than the diagonal dimension of the hexagonal nut 17 to be tightened, and B is the hexagonal chamber 50 which is a regular hexagon with reference to 0. α is the abutment of the Taber chamber 51. The angle of the taper forming the surface is preferably 50 degrees to 45 degrees. However, if the socket 9 is made of synthetic resin with low sliding friction, it may be over 45 degrees. The larger α is, the easier it is for the hexagonal shaft 17 to enter the hexagonal chamber 50, and the lower the C of the Taber chamber 51 is, the better.

Technique chamber 51 that can tolerate the size of misalignment and angle misalignment
With a diameter of 0, the lower the height C, which is the metal height, the more effective it will be without being an obstacle during fastening.

Some examples will be described below regarding an example in which Figures 1 to 3 are applied when a hexagonal nut is fastened to a threaded rod of a nodle of a valve in a fN m unit. and then tighten hexagonal nuts etc. In this case, the main body of the valve is placed on a jig with a rough surface, but at this time, the angular deviation θ, the simple deviation X1, and the vertical deviation y shown in FIG. Sometimes there are multiple discrepancies.

This is because the surfaces of both threads do not match up with the rough outer surface of the valve body and the rough top surface of the jig. If the cam mechanism of the pin 4 and groove 5 shown in the present invention is used in the upper stage and the elastic body 8 is used in the lower stage, and the hexagonal nut 17 is attracted by the magnet 10 to prevent it from falling during fastening, it is easy ( /
r1 It is possible to smoothly fasten the hexagonal nut 17 to Bo/l-), and it is effective in all cases where the nut is fastened to a bolt when attached to a robot hand, and can be used as a nut fastening unit. can.

〔Effect of the invention〕

When fastening the hexagonal nut 17 to the threaded portion 19 of the stud bolt 18, with respect to the axis of the hexagonal nut 17 to be fastened,
Even if the shaft center of the stud bolt 18 is misaligned, the hexagonal nut 17 can be fastened. A detailed explanation will be given below with reference to FIG.

That is, when the axis of the hexagonal nut 17 is made positive,
Even if the shaft center of the stud bolt 18 is greatly misaligned, it can be fastened. This deviation may include an angular deviation θ or simply a misalignment of the center, but the present invention has a satisfactory effect in both cases.

If the hexagonal nut 17 and the stud bolt 18 have a vertical deviation of the dimension Z with respect to the base line XX, then the pin 4 and fI! The cam mechanism formed by 85 causes vertical relief, and the action of the bullet 8 also allows for some degree of relief. In the Y-Y direction, there are cases where the angle deviation is θ, and there are cases where the deviation is x with respect to Y-Yi and the deviation is Y, -Y. Furthermore, although there are cases where the angular deviation θ and the simple center deviation X are combined, the present invention satisfies all of these.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the present invention, FIG. 2 is a detailed diagram showing the cam mechanism of the pin 4 and groove 5 in FIG. 1, and FIG. 3 is a detailed sectional view showing part A in FIG. 1. Figure 4 is an explanatory diagram showing the misalignment of the bolt head with respect to the hexagonal nut, and Figure 5 is a diagram showing the conventional example. 1: Motor 4 Pin 5: Groove 8: Bullet 10, magnet 50: Hexagonal chamber 51: Theba chamber

Claims (1)

[Claims] In an automatic nut tightening device that fastens a hexagonal nut to a bolt using a socket with a hexagonal recess on the transmission shaft rotated by a motor, a pin that penetrates the transmission shaft and protrudes at both ends is provided and is fitted onto the transmission shaft. A groove is provided in the hollow shaft, a pin is inserted into this groove, and the hollow shaft is connected to a socket via a plurality of elastic bodies below the hollow shaft, and a magnet, a hexagonal chamber, and a taper are provided in the recessed part at the bottom of the socket. . An automatic nut tightening device characterized in that the spiral groove moves in conjunction with the deflection of the elastic body.