Device for screwing nut to bolt and method for screwing nut to bolt using the same

Abstract

To provide a screwing device which quickly screws a bolt and a nut corresponding to various specifications by simple operation by a worker, for integrating the nut and bolt and making the nut and bolt a pair, and which can be easily carried and inexpensive, and a method for screwing a nut to a bolt.SOLUTION: A device for screwing a nut to a bolt comprises: a columnar nut holding body 3 which is detachably fitted to a bearing member 2 coupled to an output shaft 11 of a motor 1 and rotates on a vertical axis. On the nut holding body 3, there is formed on its top face center part, a bottomed cylindrical nut storage space 4 having an inner diameter at which a prescribed nut 5 may be loosely fitted, the nut storage space being opened vertically upper side. The nut holding body 3 is inserted from an insertion hole 60 formed with an opening diameter at which the nut holding body may be inserted loosely into a horizontal plate-shaped table 6, in a state of exposing the top face of the nut holding body 3. On one place of an inner peripheral face of the nut storage space 4, there is provided a groove 41 continuous from an upper end edge to an inner bottom face part, where the groove may be formed vertically downwardly.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a screwing device for screwing a nut onto a bolt conforming to various standards to form a pair, and to a method of screwing a nut onto a bolt using the same. [Background technology]

[0002] Conventionally, the bolt-nut screwing device rotates either the bolt or the nut on its axis, and in the case of mass processing, it is performed by a large, fully automatic device, which is efficient. On the other hand, in the case of small-volume processing of multiple specifications, it is currently performed manually by an operator. Performing this with a large machine device is not only difficult to work with due to the complicated setup, but also extremely uneconomical when the cost of the device is taken into consideration.

[0003] Furthermore, even in small quantities, the method of manually screwing together a variety of bolts and nuts requires workers to be under tension for long periods of time, which can lead to variations in the positioning of the nuts on the bolts, making the work less efficient and less stable to handle.

[0004] To solve this problem, for example, Patent Documents 1 and 2 disclose automated machinery that uses a sensor or the like to detect the position at which a nut is screwed onto a bolt. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 06-074238 [Patent Document 2] JP 2019-123036 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the above-mentioned disclosed inventions are automated machines with many components, which makes maintenance complicated. Also, most of the devices are large and fixed, which makes them difficult to transport. Naturally, such devices are expensive, and are not easy to operate and transport.

[0007] The present invention has been made in consideration of the above problems, and has as its object to provide a screwing device that enables an operator to quickly screw together bolts and nuts that comply with various standards to form an integrated pair with simple operation, and that is easy to transport and move, and is inexpensive, and a method of screwing nuts onto bolts using the same. [Means for solving the problem]

[0008] In order to solve the above problems, the device for screwing a nut onto a bolt according to the present invention is configured as follows.

[0009] That is, the nut holder has a cylindrical nut holder that is removably attached to a bearing member connected to the output shaft of a motor and rotates on a vertical axis, and the nut holder has a bottomed cylindrical nut storage space in the center of its upper surface that opens vertically upward and has an inner diameter that allows a specified nut to fit loosely into it, and the nut holder is inserted and held in an installation opening formed with an opening diameter that allows it to fit loosely into a horizontal plate-like table, with the upper surface of the nut holder exposed.

[0010] Also, a groove may be formed vertically downward at one location on the inner peripheral surface of the nut storage space, which groove is continuous from the upper edge to the inner bottom surface. With this, when the bolt is plated or painted, the corners on the outer peripheral side of the nut come into contact with the edge of the groove, generating a rotational force, which, combined with the rotational force due to contact friction, can increase the screwing force of the nut.

[0011] Furthermore, the nut screwing device for the bolt employs a method in which a nut holder having a bottomed cylindrical nut storage space with an inner diameter that allows a nut of a specified standard to fit loosely is opened in the center of the top surface and detachably connected to a motor to rotate on a vertical axis, a nut of a specified standard is stored in the rotating nut storage space, and while the nut is rotated on its axis due to friction with the bottom of the nut storage space, the tip of the bolt is abutted against the screwing opening of the rotating nut, and the nut is screwed into the vicinity of the tip of the bolt. Effect of the Invention

[0012] The above configuration provides the following advantages.

[0013] By replacing the nut holder that corresponds to multiple standards, it is possible to quickly respond to high-mix low-volume production. By rotating the nut by the contact friction with the inner bottom surface of the nut storage space, the time required to attach it to the bolt can be shortened and work efficiency can be improved. [Brief description of the drawings]

[0014] [Figure 1] 1 is a plan view showing the overall configuration of this embodiment, partly in vertical section. FIG. [Diagram 2] FIG. 2 is a perspective view showing the corresponding relationship of the main parts of the embodiment; [Diagram 3] 5A to 5C are schematic perspective views showing each step of screwing a nut onto a bolt in this embodiment. [Figure 4] 5A to 5C are schematic perspective views showing each step of screwing a nut onto a bolt in this embodiment. [Diagram 5] 5A to 5C are schematic perspective views showing each step of screwing a nut onto a bolt in this embodiment. [Figure 6] 5A to 5C are schematic perspective views showing each step of screwing a nut onto a bolt in this embodiment. [Figure 7] 5A to 5C are schematic perspective views showing each step of screwing a nut onto a bolt in this embodiment. [Figure 8]5A to 5C are schematic perspective views showing each step of screwing a nut onto a bolt in this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention (hereinafter, referred to as the "present embodiment") will be described in detail with reference to the drawings.

[0016] The motor 1 shown in the figure serves as a drive source, and is mounted on a base 10 arranged at a predetermined position in a housing (not shown), with the rotation axis of the output shaft 11 of the motor 1 facing vertically upward. A bearing member 2 is attached to the output shaft 11. This bearing member 2 is detachably connected to a nut holder 3 (described later) to transmit the axial rotation force.

[0017] In this embodiment, as shown in the figure, the bearing member 2 is attached directly to the output shaft 11 of the motor 1, but it is not limited to this and although not shown in the figure, a structure may be adopted in which the axis of the bearing member 2 is arranged vertically upward by connecting it to the output shaft 11 of the motor 1 with a gear, belt, etc.

[0018] The bearing member 2 bears the rotation of the nut holder 3, which has a cylindrical external appearance. In this structure, a cylindrical fitting protrusion 30 is integrally formed, which protrudes vertically downward from the center of the bottom outer side of the nut holder 3. The fitting protrusion 30 is formed to fit into a cylindrical fitting recess 20 that opens upward from the center of the bearing member 2. The specification of this fitting is such that a part of the outer circumferential surface of the fitting protrusion 30 is cut out along the axis to form a D-cut surface 31, and a protruding surface 21 is formed in the fitting recess 20 to fit with the D-cut surface 31. With this structure, the bearing member 2 can be freely attached and detached in the vertical direction, and only the axial rotation force is transmitted by the abutment between the D-cut surface 31 and the protruding surface 21. Note that this fitting structure that transmits only the rotation force is a general known technology, and may be, for example, a key connection structure.

[0019] In the central part of the upper surface of the nut holder 3, a cylindrical nut storage space 4 with a bottom is formed, having a depth approximately equal to the height of the nut 5 vertically downward (for example, about 25 mm in the case of M20) and an inner diameter (for example, about 35 mm in the case of M20) that fits loosely into the outer diameter of the nut 5 (circumscribing it with a small gap).

[0020] Further, a groove 41 is formed vertically downward on the inner peripheral surface 40 of the nut storage space 4, continuing from the opening edge to the inner bottom surface 42. The formation of this groove 41 is not essential, but depending on the product specifications of the bolt 7, the thread groove may be plated or painted, which helps to increase the screwing force of the nut 5.

[0021] Furthermore, a part or all of the inner bottom surface portion 42 of the nut storage space 4 is formed in a flat surface perpendicular to the vertical rotation axis, but this is not limited to this, and a donut-shaped flat surface portion (which becomes the contact surface portion with the nut) may be formed near the inner peripheral surface 40 of the inner bottom surface portion 42.

[0022] The nut holder 3 is inserted and held in a horizontal plate-like table 6, which will be described later, through an installation opening 60 formed with an opening diameter that allows the nut holder 3 to be loosely fitted into the table 6, with the upper surface of the nut holder 3 exposed. In this embodiment, the nut holder 3 is set to be approximately flush with the plate surface of the table 6.

[0023] With this configuration, the table 6 is positioned, which makes it possible to quickly insert and install the nut holder 3 into the installation port 60 (see Figure 3), and since the upper surface of the nut holder 3 and the table 6 are approximately flush with each other, the nut 5 can be stored and held in the nut holder 3 by simply sliding it (see Figure 4), thereby improving workability. [Work Procedure] Next, an operating procedure for the device for screwing a nut onto a bolt having the above-mentioned configuration will be described.

[0024] First, the nut holder 3 having the nut storage space 4 that is suitable for the nut 5 to be screwed onto the target bolt 7 is inserted into the fitting recess 20 of the bearing member 2 to which the motor 1 is attached, with the fitting protrusion 30 facing downward from the installation opening 60 opened in the table 6.

[0025] (See FIG. 3.) At this time, as described above, the D-cut surface 31 formed on the fitting protrusion 30 comes into contact with the protruding surface 21, thereby enabling attachment and detachment in the vertically upward direction while enabling the transmission of axial rotation force.

[0026] Next, while driving the motor 1 to rotate the nut holder 3, the desired standard nut 5 is slid on the table 6 and stored in the nut storage space 4 with the screwing opening 50 facing vertically upward (see FIG. 4). This storage brings the underside of the nut 5 into contact with the inner bottom surface 40 of the nut storage space 4, and the nut 5 rotates axially due to the contact friction (see FIG. 5).

[0027] While maintaining this rotation, the tip of a specified bolt 7 is brought close to the screw-in opening 50 of the nut 5 and pressed into contact (brought into contact while applying pressure). The nut 5 then automatically screws into the bolt 7, moves upward, and separates from the inner bottom surface portion 40, eliminating contact friction and ending the rotation (see Figure 6).

[0028] At this point, the grasped bolt 7 has the nut 5 screwed near the tip end (see FIG. 7), which is convenient for handling during bolt and nut work (see FIG. 8).

[0029] In addition, some bolts 7 have plated or painted threads, and for bolts 7 of this specification, the contact friction between the lower surface of the nut 5 and the inner bottom surface 40 of the nut storage space 4 alone is weak enough to screw the nut 5 in sufficiently. Taking this into consideration, a groove 41 is formed in the inner peripheral surface 40 of the nut storage space 4, which continues vertically downward from the upper edge of the opening to the bottom surface.

[0030] By forming such grooves 41, the hexagonal portion on the outer periphery of the nut 5 comes into contact with the edge of the grooves 41 while the nut 5 is rotating, and further rotational force can be applied. This makes it possible to increase the rotational torque of the nut 5.

[0031] As described above, by preparing various nut holders 3 each having a nut storage space 4 corresponding to each standard nut 5 and replacing them as necessary, it is possible to quickly combine nuts 5 of various standards with bolts 7. This makes it possible to significantly improve workability compared to conventional manual work. [Explanation of symbols]

[0032] 1 Motor 10 Foundations 11 Output shaft 2 Bearing materials 20 Fitting recess 21 Protruding surface 3 Nut holder 30 Fitting protrusion 31 D-cut surface 4 Nut storage space 40 Inner surface 41 Groove 42 Inner bottom part 5 Nut 50 Threaded part 6 Tables 60 Installation port 7 Volts

Claims

1. a cylindrical nut holder that is detachably attached to a bearing member that is connected to an output shaft of a motor and that rotates about a vertical axis; The nut holder has a bottomed cylindrical nut storage space formed in the center of its upper surface, the bottomed cylindrical nut storage space having an inner diameter large enough to allow a predetermined nut to be loosely fitted therein, the nut storage space being open vertically upward, The nut holder is inserted and held in an installation hole formed with an opening diameter that allows it to be loosely fitted onto a horizontal plate-shaped table, with the upper surface of the nut holder exposed.

2. 2. The device for screwing a nut onto a bolt according to claim 1, wherein a groove portion is formed vertically downward at one location on the inner peripheral surface of the nut storage space, the groove portion continuing from the upper edge portion to the inner bottom surface portion.

3. A nut screwing device is used for the bolt, A nut holder having a bottomed cylindrical nut storage space with an inner diameter that allows a nut of a specified standard to be loosely fitted in the center of the upper surface is rotated on a vertical axis by a motor, A nut of a predetermined standard is stored and held in the nut storage space that is rotating on the axis, and the nut is rotated on the axis by contact friction between the lower surface of the nut and the inner bottom surface of the nut storage space, Next, the tip of the bolt is pressed against the threaded portion of the nut which is rotating while being stored and held in place, and the nut is threadedly attached near the tip of the bolt.

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