JPH06155191A - Supporting device for screw tightening machine unit - Google Patents

Abstract

PURPOSE:To perform smooth screw tightening whale preventing a thread ridge and a screw hole opening part from being damaged, even in both the cases placed eccentrically and not eccentrically, by supporting a screw tightening machine unit in a condition that it can be elastically displaced relating to a conveying main unit of an automatic conveyer. CONSTITUTION:When a bolt head part 21 is fitted into an engaging hole 22 by a short stroke of an air cylinder 2, a holding member 24 is immediately retracted, and thereafter a bolt is moved toward a screw hole 16 at a high speed by the air cylinder. Thus when a point end of the bolt is hit against an opening part of the screw hole 16, since a shaft 17 is relatively displaced while compressing a coil spring 20, an impact in this hitting part is relaxed to prevent a thread ridge from being damaged. Similarly even in the case placed eccentrically, the opening part of the screw hole 16 is prevented from being damaged by cushioning action by the coil spring 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supporting device for a screw tightening unit, and is used in the field of an automatic carrying device, that is, a robot.

[0002]

2. Description of the Related Art It is known to screw a supply rod by rotating and advancing and retracting the supply rod at the same time by means of a rotational driving means and an advancing / retreating driving means. Then, such a screw tightener unit is coupled to the carrier body of the automatic carrier device.
To describe the conventional technique in detail with reference to FIG. 4, an air cylinder 2 and a guide rail 3 are coupled to a substrate 1, and a rotary motor 5 is fixed to a slide piece 4 aligned with the guide rail 3. The piston rod 6 of the air cylinder 2 is connected to the rotary motor 5, and further the supply rod 7
Are rotated by the rotary motor 5. The structure described above is the screw tightener unit 8.

There are various types of automatic carrier devices, that is, robots in which an arm rotates and a robot moves in and out by an air cylinder. The automatic carrier device here is an air cylinder 10 as indicated by reference numeral 9. Is the main subject. The air cylinder 10 is fixed to a stationary member 11, and its main body 13 is connected to its piston rod 12. The substrate 1, that is, the screw fastening unit 8 is fixed to the transport main body 13 via the interstitial material 14.

A bolt or nut (not shown in FIG. 4) held at the tip of the supply rod 7 is made to reach a target position at high speed by the operation of the air cylinder 10, and the tip of the bolt is, for example, a screw hole of the counterpart. When it comes into contact with, the screw is tightened by the rotation of the rotary motor 5 at a proper speed and the low speed feed by the air cylinder 2.

[0005]

In the above-mentioned prior art, since the bolt or the like can reach the target location at high speed, the bolt 15 and the screw hole 16 are eccentric as shown in FIG. When the tip corner portion of the bolt 15 hits the opening portion of the screw hole 16, that portion is damaged or cannot be screwed normally with the tip portion still hit.

[0006]

Means for Solving the Problem and Its Action The present invention was devised by focusing on the above-mentioned problems, and a screw tightener unit for operating the supply rod by the rotation driving means and the advancing / retreating driving means is provided. It is characterized in that it is supported in a state where it can be elastically displaced with respect to the transfer body of the automatic transfer device.When the bolt or nut comes into contact with the other party, elastic displacement is allowed, so a smooth screw Narrowing is started.

[0007]

EXAMPLES Examples of FIGS. 1 to 3 will be described. Components having the same functions as those of FIG. 4 are denoted by the same reference numerals and detailed description thereof is omitted. Axis 17 on board 1
The shaft 17 is slidably penetrated into the through hole 18 formed in the carrier body 13, and the flange 19 integral with the shaft 17 abuts the upper surface of the carrier body 13 to prevent the shaft 17 from coming off. The coil spring 20 is interposed between the substrate 1 and the transfer main body 13, whereby the screw tightening unit 8 is supported in a state of being elastically displaceable with respect to the transfer main body 13.

An engaging hole 22 for receiving the head 21 of the bolt 15 is formed at the tip of the supply rod 7. Since the head portion 21 has a hexagonal shape, the engagement hole 22 has a dodecagonal shape or 18
If it is formed in a rectangular shape, the head portion 21 is smoothly fitted into the engagement hole 22. A magnet (permanent magnet) 23 is embedded in the inner part of the engagement hole 22. The bolt 15 is held at a position away from the axis of the supply rod 7, and then moved to a position coaxial with the supply rod 7 as shown. For that purpose, a holding member 24 and a transfer rod 25, which are shown by a chain double-dashed line, are installed.

With reference to FIG. 3, the section (3)-(3) of FIG. 1 will be described. The guide rail 3 has a square C-shaped section, and the slide piece 4 is slidably fitted therein. The slide piece 4 is inserted in a so-called dovetail groove.

The operation of the above embodiment will be described below.
When the head 21 is fitted into the engagement hole 22 due to the short stroke of the air cylinder 2, the holding member 24 immediately retracts, and thereafter the air cylinder 10 shown in FIG. 4 (not shown in FIG. 1 is omitted). It moves toward the screw hole 16 at high speed. When the tip of the bolt 15 hits the opening of the screw hole 16 in this way, the shaft 17 is rotated by the coil spring 2.
Since the relative displacement is carried out while compressing 0, the impact at this contact point is alleviated and damage to the screw thread is prevented.
Similarly, even in the case of eccentricity as shown in FIG. 5, the opening of the screw hole 16 is prevented from being damaged by the buffering action of the coil spring 20.

To explain the embodiment of FIG. 2, the shaft 17 penetrates the inside of the sleeve 26, and the elastic rubber 27 is interposed on the outside thereof. By doing this, the supply rod 7
It further enhances the absorption of elastic displacement in the swaying direction.

In the above embodiments, bolts are used, but nuts may be used instead.

[0013]

[Effects] According to the present invention, since the elastically displacing structure is employed as described above, the thread and the screw can be used regardless of whether they are eccentric or eccentric. A smooth screw tightening function is achieved while preventing damage to the hole opening.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a partial vertical sectional side view showing another embodiment.

FIG. 3 is a sectional view taken along line (3)-(3) of FIG.

FIG. 4 is an overall side view of a conventional example.

FIG. 5 is a vertical cross-sectional view showing a state in which a bolt and a screw hole are eccentric.

[Explanation of symbols]

 5 rotation driving means 2 advancing / retreating driving means 7 supply rod 8 screw tightening unit 9 automatic carrier device 13 carrier body

Claims (1)

[Claims] 1. A screw tightening unit characterized in that a screw tightening machine unit for operating a supply rod by a rotation driving means and an advancing / retreating driving means is supported in a state of being elastically displaceable with respect to a conveying body of an automatic conveying apparatus. Device support equipment.