WO2021251740A1

WO2021251740A1 - Bolting gripper, bolt fastening device including same, and bolt fastening method

Info

Publication number: WO2021251740A1
Application number: PCT/KR2021/007184
Authority: WO
Inventors: 배지훈; 이동혁; 박재한; 장가람; 최명수
Original assignee: 한국생산기술연구원
Priority date: 2020-06-09
Filing date: 2021-06-09
Publication date: 2021-12-16
Also published as: KR20210152881A; KR102370259B1

Abstract

An embodiment of the present invention relates to a bolting gripper, a bolt fastening device including same, and a bolt fastening method. The bolting gripper according to an embodiment of the present invention comprises: a fastening part for fastening a bolt in a screw hole of a workpiece located under the bolt; a grip part for holding the bolt; a moving part for moving the grip part so as to allow the bolt to be inserted into the fastening part; and an elastic part which is connected to the fastening part and absorbs an impact transferred when the bolt is bent upward while being inserted into the fastening part.

Description

Bolting gripper, bolting device including same, and bolting method

The present invention relates to a bolting gripper capable of inserting and fastening a bolt into a screw hole of a workpiece, a bolt fastening device including the same, and a bolt fastening method.

A bolt is one of the mechanical elements required for assembling various mechanical devices. In the case of fastening the bolts, a tool such as a spanner is generally used. However, when a tool such as a spanner is used, a lot of force is required, a lot of manpower is input, and there is a problem in that the working time is long.

Therefore, conventionally, a hand power tool capable of reducing working time in consideration of productivity has been used. And, furthermore, to maximize productivity, an automated bolt fastening device capable of directly performing bolt fastening work on an automatic assembly line was used.

In the bolt fastening device of the prior art, the bolt fastener is fastened to the lifting panel, and the lifting panel is raised and lowered by the driving of the lifting cylinder to fasten the bolt to the screw hole of the workpiece.

In the case of the existing bolt fastening device, since it can only move up and down, there is no degree of freedom for the bolt to flow forward or backward within a certain range. Therefore, when the bolt coupled to the bolt fastener is slightly deviated from the screw hole during the bolt fastening operation, the bolt cannot be fastened to the screw hole, and there is a problem in that the bolt is damaged or the work object is damaged.

In addition, in the case of the conventional bolt fastening device, as a separate bolt supply device for aligning and supplying bolts is required, the bolt fastening device has become larger and requires a large space, and there is a problem that the installation cost is also increased.

It was devised based on the technical background as described above, and an embodiment of the present invention includes a bolting gripper capable of inserting and fastening a bolt into a screw hole even if the bolt deviates from the screw hole of a work object within a certain range, including the same An object of the present invention is to provide a bolt fastening device and a bolt fastening method.

In addition, an embodiment of the present invention is to provide a bolting gripper capable of grabbing misaligned bolts and automatically fastening them to the screw holes after moving them to the screw holes, a bolt fastening device including the same, and a bolt fastening method.

In order to achieve the above object, a bolting gripper according to an embodiment of the present invention includes: a fastening part for fastening the bolt to a screw hole of a work object located under the bolt; a grip portion for holding the bolt; a moving part for moving the grip part so that the bolt is inserted into the fastening part; and an elastic part connected to the fastening part and buffering the shock transmitted when the bolt is inserted into the fastening part by bending upward.

In addition, the fastening part, a fastening motor formed so that the head of the bolt is coupled to one end; It may include a guide member formed on one side of the fastening motor to prevent vibration of the fastening motor in contact with the work object when the bolt is inserted into the screw hole of the work object to a first depth.

In addition, the guide member may be formed to move upwardly along the outer surface of the fastening motor so as to contact the work object as the bolt is inserted deeper than the first depth into the screw hole of the work object.

In addition, the lower end of the guide member may be formed in a tapered shape to match the central axis of the bolt and the rotation axis of the fastening motor.

In addition, the first moving groove is formed on the upper side of the elastic part, and the second moving groove is formed on the lower side so that when the bolt receives a pressing force for pressing the fastening part, the interval between the second moving grooves increases, and the The gap between the first moving grooves may be reduced.

In addition, a bump may be formed in the second moving groove to prevent a gap between the second moving grooves from being reduced.

In addition, the elastic part may include a buffer member formed in a corrugated form in the vertical direction.

In addition, a plurality of bumps for preventing the buffer member from being bent downward may be provided at the lower end of the buffer member, and the plurality of bumps may be formed to contact each other.

In addition, the elastic portion may include a bar-shaped preventing member disposed on at least one side portion to prevent the elastic portion from being trusted.

On the other hand, in order to achieve the above object, the bolt fastening device includes the above-described bolting gripper; a driving unit for driving the bolting gripper so that the bolt is easily inserted into the screw hole; and a control unit for controlling the driving unit.

In addition, the driving unit may include a first driving member having a first driving shaft formed in a direction perpendicular to the insertion direction of the bolt, and a second driving member connected to the first driving member and having a second driving shaft parallel to the first driving shaft. and wherein the first driving member and the second driving member rotate about the first driving shaft and the second driving shaft, respectively, to move the bolting gripper so that the bolt is easily inserted into the screw hole. .

In addition, the control unit may move the first and second driving members so that the bolt is inserted into the correct position of the screw hole.

On the other hand, in order to achieve the above object, the bolt fastening method is a fastening method of a bolt using the above-described bolt fastening device, comprising: holding the bolt with a grip part; matching the central axis of the bolt with the central axis of the fastening part; coupling the bolt to the fastening part; moving the fastening part to the screw hole of the workpiece; and inserting and fastening the bolt into the screw hole.

In addition, the step of inserting and fastening the bolt into the screw hole may include matching a central axis of the bolt with a central axis of the screw hole.

In addition, the step of inserting and fastening the bolt into the screw hole may include separating the grip portion from the bolt when the bolt is inserted into the screw hole at a depth greater than or equal to a set depth.

In the bolting gripper according to an embodiment of the present invention, since the elastic part is bent upward to cushion the shock transmitted when the bolt is inserted into the fastening part, damage to the fastening part can be prevented.

Since the bolting gripper according to an embodiment of the present invention can provide a degree of freedom to the bolt through the driving part and the elastic part during the bolt fastening operation, even if the bolt deviates from the screw hole of the workpiece within a certain range, the bolt is inserted into the screw hole. can be fastened.

The bolting gripper according to an embodiment of the present invention does not require a separate bolt supply device for arranging and supplying bolts, thereby reducing the installation space, thereby reducing installation costs.

1 is a perspective view showing a bolting gripper according to an embodiment of the present invention.

2 is a perspective view illustrating a grip portion of a bolting gripper holding a bolt according to an embodiment of the present invention.

3 is a perspective view illustrating that the moving part of the bolting gripper according to an embodiment of the present invention moves the grip part toward the fastening part to match the central axis of the bolt and the central axis of the fastening part.

4 is a perspective view illustrating that the bolt fastening device according to an embodiment of the present invention moves the bolting gripper to a screw hole of a work object and matches the central axis of the bolt with the central axis of the screw hole.

5 is a view showing a fastening portion and an elastic portion of the bolting gripper according to an embodiment of the present invention.

6 is a side view illustrating a fastening part and an elastic part of the bolting gripper according to an embodiment of the present invention, and showing that a bolt is inserted into the fastening part.

7 is a side view illustrating that an elastic part is bent upward during a bolt fastening operation using a bolting gripper according to an embodiment of the present invention.

8 is a flowchart illustrating a bolt fastening method according to an embodiment of the present invention.

9 shows an algorithm of a bolt fastening method according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, the embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

In the present specification, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

As shown in Fig. 1, in the grip part, the fastening part side is defined upward, and in the fastening part, the grip part side is defined and explained, and in the driving part, the fastening part side is defined and explained forward, and in the fastening part The driving part side is defined as the rear and will be described.

1 to 7 , the bolting gripper 10 according to an embodiment of the present invention may include a fastening part 300 , a grip part 400 , a moving part 500 , and an elastic part 200 . .

The fastening unit 300 includes a fastening motor 310, and a guide member 330 to fasten the bolt (B) to the screw hole (30h) of the work object 30 located under the bolt (B). can

The fastening motor 310 may be formed so that the head Ba of the bolt is coupled to one end. In addition, a coupling part 311 rotated by the fastening motor 310 and coupled to the head Ba of the bolt may be provided at one end of the fastening motor 310 .

Additionally, the coupling part 311 may include a coupling member and a bolt tip. In addition, the coupling member may be connected to the fastening motor 310 and rotated by the fastening motor 310 . In addition, one end of the bolt tip may be connected to the coupling member and the other end may be connected to the head Ba of the bolt. And, the bolt tip is rotated together as the coupling member is rotated to rotate the bolt (B), thereby fastening the bolt (B) to the screw hole (30h).

The guide member 330 may be formed on one side of the fastening motor 310 . And, the guide member 330 is in contact with the work object 30 when the bolt (B) is inserted to the first depth into the screw hole 30h of the work object 30 to prevent the vibration of the fastening motor 310. have. Here, the first depth is when the bolt (B) is inserted into the screw hole (30h) and spaced apart from the bolt (B) while the grip part 400 places the bolt (B) in the middle of the fastening, the bolt (B) is the screw hole ( 30h) may be inserted in length.

And, the guide member 330 is the outer surface of the fastening motor 310 so as to be in contact with the work object 30 as the bolt (B) is inserted deeper than the first depth into the screw hole 30h of the work object 30 . Therefore, it may be formed to move in an upward direction. In addition, the lower end of the guide member 330 may be formed in a tapered shape to match the central axis of the bolt B and the rotation axis of the fastening motor 310 .

Additionally, the guide member 330 may be connected to the fastening motor 310 through the elastic member, move in the upper direction, and then move in the lower direction through the elastic force of the elastic member to return to the original position.

Additionally, a protective body 320 that surrounds and protects the coupling part 311 may be provided on one side of the fastening motor 310 . In addition, the guide member 330 may be formed to move upward along the outer surface of the protective body 320 . In addition, the guide member 330 may be provided with an elastic spring TS, and may be moved downward through the elastic force of the elastic spring TS to return to the original position.

In more detail, an elastic spring TS may be provided between the guide member 330 and the protective body 320 . Then, the guide member 330 is connected to the protective body 320 and the elastic spring TS to move in the upward direction, and then is moved in the downward direction through the elastic force of the elastic spring TS to return to the original position. .

Additionally, when the screw hole 30h of the workpiece 30 is opened in the lower direction, the guide member 330 is moved in the lower direction and then moved upward through the elastic force of the elastic spring TS. It can be returned to its original position.

The grip part 400 may hold the bolt (B). In addition, the grip part 400 may be provided as a pair, and a grip groove 400h into which the bolt B is fitted may be formed on the opposite surface. In addition, the grip part 400 may be moved so as to abut against each other, and the bolt B may be caught by the grip part 400 by fitting the body Bb into the grip groove 400h.

The moving part 500 may move the grip part 400 so that the bolt B is inserted into the fastening part 300 .

Additionally, the bolting gripper 10 according to an embodiment of the present invention may be connected to the robot arm 40 and moved from the vicinity of the bolt B to the vicinity of the screw hole 30h of the workpiece 30 . In addition, the elastic unit 200 may be connected to the upper portion of the robot arm 40 , and the moving unit 500 may be connected to the lower portion of the robot arm 40 .

Additionally, the moving unit 500 may include a first moving member 510 , a second moving member 520 , and a connecting member 530 . The first moving members 510 may be provided as a pair, and may be respectively installed to face each other while being spaced apart from each other at a predetermined distance in the lower portion of the robot arm 40 . In addition, the second moving member 520 may have one end connected to the first moving member 510 and may be rotated upward or downward through the first moving member 510 .

The connecting member 530 may have one end connected to the second moving member 520 and the other end connected to the grip unit 400 . In addition, the connecting member 530 may be rotated to the left or right through the second moving member 520 with respect to the second moving member 520 . In addition, the grip part 400 may be rotated along with the connecting member 530 .

In summary, the grip unit 400 may be moved toward the bolt B through the moving unit 500 to hold the bolt B, and may be moved toward the fastening unit 300 .

The elastic part 200 may be connected to the fastening part 300 . Referring to FIG. 6 , the elastic part 200 may buffer the shock transmitted when the bolt B is inserted into the fastening part 300 by bending upward.

In addition, in the elastic part 200 according to the first embodiment, a first moving groove 200a may be formed on an upper side, and a second moving groove 200b may be formed on a lower side. In addition, in the elastic part 200 according to the first embodiment, when the bolt B receives a pressing force for pressing the fastening part 300 , the gap between the second moving grooves 200b increases, and the first moving groove 200a ) may be formed such that the interval between them is reduced. In addition, the second moving groove (200b) may be provided with a bump 240 to prevent the gap between the second moving grooves (200b) from being reduced.

Accordingly, the elastic part 200 according to the first embodiment may be bent upward, and the shock transmitted when the bolt B is inserted into the fastening part 300 may be buffered. In addition, the elastic part 200 may include a preventing member 250 disposed on at least one side portion. The preventing member 250 may prevent the elastic part 200 from being trusted. That is, the preventing member 250 may prevent the elastic part 200 from being twisted.

In addition, the elastic part 200 according to the second embodiment may include a rear end bracket 210 , a front end bracket 220 , and a buffer member 230 .

The rear end bracket 210 may be connected to the upper portion of the robot arm 40 . In addition, the shear bracket 220 may be connected to the fastening part 300 . In addition, the buffer member 230 is formed in the form of corrugations in the vertical direction may be bent in the vertical direction. In addition, the buffer member 230 may be bent upward to buffer the shock transmitted when the bolt B is inserted into the fastening part 300 .

In addition, a plurality of bumps 240 for preventing the buffer member 230 from being bent downward may be provided at the lower end of the buffer member 230 . In addition, the plurality of bumps 240 are formed to be in contact with each other to prevent the buffer member 230 from being bent downward due to gravity.

The bolt fastening device 20 provides a degree of freedom to the bolt B so that the bolt B can perform the bolt fastening operation even if the bolt B deviates from the screw hole 30h within a certain range. The bolting gripper 10, the driving unit (100) and may include a control unit.

Since the bolting gripper 10 has the same configuration as described above, a detailed description thereof will be omitted.

The driving unit 100 may drive the bolting gripper 10 so that the bolt B is easily inserted into the screw hole 30h. In addition, the driving unit 100 may include a first driving member 110 and a second driving member 120 . In addition, the first driving shaft 111 may be formed in the first driving member 110 in a direction perpendicular to the insertion direction of the bolt (B). In addition, the first driving shaft 111 may be connected to the upper portion of the robot arm 40 . In addition, a second driving shaft 121 connected to the first driving member 110 and parallel to the first driving shaft 111 may be formed on the second driving member 120 . Also, the second driving member 120 may be connected to the elastic part 200 .

In addition, the first driving member 110 and the second driving member 120 rotate about the first driving shaft 111 and the second driving shaft 121, respectively, so that the bolt B is easily inserted into the screw hole 30h. The bolting gripper 10 can be moved to be inserted.

Referring to FIG. 4 , when the first driving member 110 rotates about the first driving shaft 111 , the fastening part 300 may move downward and rearward. And, when the second driving member 120 rotates about the second driving shaft 121 , the fastening part 300 may move downward and forward.

The controller may move the first and second driving

members

110 and 120 by controlling the driving unit 100 so that the bolt B is inserted into the correct position of the screw hole 30h. And, as the first and second driving

members

110 and 120 are operated, the fastening part 300 may be moved forward or backward and may be lowered. Accordingly, the driving unit 100 is able to provide a degree of freedom to the bolt (B).

Referring to FIG. 7 , the fastening part 300 may be rotated as it descends during the bolt fastening operation. Accordingly, the central axis of the bolt (B) may deviate from the central axis of the screw hole (30h). At this time, the elastic part 200 can be prevented from being deviating from the central axis of the screw hole (30h) by bending the central axis of the bolt (B) upward. That is, the bolt B may flow by the elastic deformation of the elastic part 200 . Accordingly, the bolt fastening device 20 may perform a bolt fastening operation while providing a degree of freedom to the bolt B through the driving unit 100 and the elastic unit 200 .

Prior to the description of the bolt fastening method, the robot arm 40 receives the position information of the bolt (B) and the screw hole 30h of the work object 30, or through a sensor connected to the robot arm 40, the bolt ( B) and the position information of the screw hole 30h of the work object 30 can be collected to specify the position of the bolt B and the screw hole 30h of the work object 30 . And, the robot arm 40 may move the bolt fastening device 20 near the bolt B or the screw hole 30h of the work object 30 .

Here, it is a known technology to receive the position information of the bolt (B) and the screw hole (30h) or to collect the position information through a sensor or the like, a detailed description will be omitted.

8 and 9, in the bolt fastening method (S10) using a bolt fastening device according to an embodiment of the present invention, the step of holding the bolt with a grip part (S100), the central axis of the bolt and the central axis of the fastening part coincide It may include a step (S200), a step of coupling the bolt to the fastening part (S300), a step of moving the fastening part to the screw hole of the work object (S400), and the step of inserting and fastening the bolt into the screw hole (S500). .

The step of holding the bolt by the grip portion (S100) may include a preparation step (S110), a moving step (S120), and a bolt gripping step (S130) to grab the bolt (B) with the grip portion 400 . In the preparation step ( S110 ), the grip part 400 may be set in a ready position to hold the bolt (B). In addition, in the moving step ( S120 ), the grip part 400 may be moved to the upper side of the bolt B through the robot arm 40 . In addition, the bolt holding step ( S130 ) may hold the bolt (B) by moving the grip unit 400 through the moving unit 500 . And, in the bolt holding step ( S130 ), the bolt (B) may be inserted into the grip groove ( 400h ) of the grip part ( 400 ) and caught by the grip part ( 400 ).

In addition, when the moving step (S120) fails, it may be re-executed from the preparation step (S110). At this time, in the preparation step (S110), the ready posture may be set to one of the remaining ready postures except for the ready posture at the time of the previous implementation. That is, the ready posture may be set in a plurality of forms.

In the step of matching the central axis of the bolt with the central axis of the fastening part ( S200 ), the grip part 400 may be moved to the lower end of the fastening part 300 through the moving part 500 . And, the central axis of the bolt (B) may coincide with the central axis of the fastening part 300 through the guide member 330 .

In the step of coupling the bolt to the fastening part ( S300 ), the head Ba of the bolt may be coupled to the fastening part 300 . And, the fastening part 300 may rotate the bolt (B). Additionally, the head Ba of the bolt may be coupled to the bolt tip of the coupling portion 311 . In addition, the bolt tip may be replaced with a tip corresponding to the head Ba of the bolt.

In the step of moving the fastening part to the screw hole of the work piece (S400), the fastening part 300 may be brought to the vicinity of the screw hole 30h. Additionally, the fastening part 300 may be moved to the vicinity of the screw hole 30h through the robot arm 40 .

The step of inserting and fastening the bolt into the screw hole (S500) is a step of matching the central axis of the bolt with the central axis of the screw hole in order to insert and fasten the bolt (B) into the screw hole 30h (S510), finding the position of the screw hole Step (S520), bolt insertion confirmation step (S530), rotation speed adjustment step (S540), bolt displacement confirmation step (S550), separating the grip part from the bolt (S560), stop confirmation step (S570), stop step ( S580) may be included.

The step (S510) of matching the central axis of the bolt and the central axis of the screw hole is performed by moving the fastening part 300 to the central axis of the bolt B coupled to the fastening part 300 and the screw hole 30h of the work object 30. ) can coincide with the central axis.

In the screw hole location finding step ( S520 ), the screw hole ( 30h ) can be located by slowly rotating the bolt ( B ) through the fastening part ( 300 ). Additionally, the bolt B flows forward or rearward by the driving unit 100 , and the grip unit 400 flows in the left or right direction through the second moving member 520 , thereby forming the screw hole 30h. You can find the location easily.

In the bolt insertion confirmation step (S530), it can be confirmed that the bolt (B) is inserted into the screw hole (30h). In the rotation speed adjustment step S540 , the rotation speed of the bolt B may be increased through the fastening unit 300 to fasten the bolt B to the screw hole 30h.

In the bolt displacement checking step ( S550 ), it can be confirmed whether the bolt B is inserted into the screw hole 30h by 1 cm or more through the movement displacement of the fastening part 300 . Here, the movement displacement of the fastening part 300 may mean a length in which the fastening part 300 descends as the bolt B is inserted into the screw hole 30h.

In the step of separating the grip part from the bolt ( S560 ), the grip part 400 may be spaced apart from the bolt B through the moving part 500 .

In the stop confirmation step ( S570 ), it may be confirmed whether the rotation of the bolt (B) is stopped or the movement displacement of the fastening part 300 is greater than or equal to the length of the bolt (B). The stopping step S580 may stop the bolt B through the fastening part 300 . Additionally, after the stopping step (S580), a removing step (S600) of removing the fastening part 300 from the bolt (B) may be further performed. Then, the bolt fastening operation may be finished.

As a result, in the bolting gripper 10 according to an embodiment of the present invention, when the bolt B is inserted into the fastening part 300 , the elastic part 200 can be bent upward to buffer the shock. Accordingly, it is possible to prevent damage to the fastening part 300 .

And, during the fastening operation of the bolt (B), the bolt (B) may flow to the front or rear side by the driving unit 100 . In addition, the bolt B may flow by elastic deformation of the elastic part 200 . Therefore, since it is possible to provide a degree of freedom to the bolt B through the driving unit 100 and the elastic unit 200 , even if the bolt B deviates from the screw hole 30h of the work object 30 within a certain range, the bolt (B) can be inserted into the screw hole (30h) to be fastened.

Then, the unaligned bolt (B) is acquired through the grip part 400 and the bolt (B) is moved to the fastening part 300 through the moving part 500, and then the bolt's head Ba in the fastening part 300. ) can be combined to perform bolting work. Therefore, since a separate bolt supply device for aligning and supplying the bolts B is not required, the installation space can be reduced, thereby reducing the installation cost.

Although the present invention has been described through preferred embodiments as described above, the present invention is not limited thereto, and various modifications and variations are possible without departing from the concept and scope of the following claims. Those in the technical field to which it belongs will readily understand.

10: bolting gripper

100: driving unit 110: first driving member

111: first drive shaft 120: second drive member

121: second drive shaft 200: elastic part

200a: first moving groove 200b; 2nd mobile home

210: rear end bracket 220: front end bracket

230: buffer member 240: bump

250: prevention member 300: fastening part

310: fastening motor 311: coupling part

320: protector 330: guide member

400: grip portion 400h: grip groove

500: moving part 510: first moving member

520: second moving member 530: connecting member

20: bolt fastening device 30: work object

30h: screw hole 40: robot arm

B : Bolt TS : Elastic spring

Claims

a fastening part for fastening the bolt to the screw hole of the work object located under the bolt;

a grip portion for holding the bolt;

a moving part for moving the grip part so that the bolt is inserted into the fastening part; and

Bolting gripper including; an elastic part connected to the fastening part and buffering the shock transmitted when the bolt is inserted into the fastening part by bending upward.
According to claim 1,

The fastening part,

a fastening motor formed so that the head of the bolt is coupled to one end;

and a guide member formed on one side of the fastening motor to contact the work object and prevent vibration of the fastening motor when the bolt is inserted into the screw hole of the work object to a first depth.
3. The method of claim 2,

The guide member is a bolting gripper formed to move upward along the outer surface of the fastening motor so as to contact the work object as the bolt is inserted deeper than a first depth into the screw hole of the work piece.
4. The method of claim 3,

A bolting gripper comprising an elastic spring provided on the guide member and returning the guide member moved in the upward direction to an original position.
3. The method of claim 2,

The lower end of the guide member is formed in a tapered shape to match the central axis of the bolt and the rotation axis of the fastening motor.
According to claim 1,

A first moving groove is formed on the upper side of the elastic part, and a second moving groove is formed on the lower side so that when the bolt receives a pressing force for pressing the fastening part, the interval between the second moving grooves increases, and the first moving groove is formed on the lower side. A bolting gripper formed to reduce the gap between the moving grooves.
7. The method of claim 6,

A bolting gripper in which a bump is formed in the second moving groove to prevent a gap between the second moving grooves from being reduced.
According to claim 1,

Bolting gripper including a buffer member formed in the form of the elastic portion corrugated in the vertical direction.
9. The method of claim 8,

A bolting gripper is provided at a lower end of the buffer member to prevent the buffer member from being bent downward, and the plurality of bumps are formed to be in contact with each other.
7. The method of claim 6,

and a bar-shaped preventing member disposed on at least one side of the elastic part to prevent the elastic part from being trusted.
A bolting gripper according to any one of claims 1 to 10;

a driving unit for driving the bolting gripper so that the bolt is easily inserted into the screw hole; and

A bolt fastening device comprising a; a control unit for controlling the driving unit.
12. The method of claim 11,

The driving unit,

a first driving member having a first driving shaft formed in a direction perpendicular to the insertion direction of the bolt; and

and a second driving member connected to the first driving member and having a second driving shaft parallel to the first driving shaft,

The first driving member and the second driving member are respectively rotated about the first driving shaft and the second driving shaft to move the bolting gripper so that the bolt is easily inserted into the screw hole.
13. The method of claim 12,

The control unit is a bolt fastening device for moving the first and second driving members so that the bolt can be inserted into the correct position of the screw hole.
As a fastening method of bolts using the bolt fastening device according to claim 11,

holding the bolt with a grip part;

matching the central axis of the bolt with the central axis of the fastening part;

coupling the bolt to the fastening part;

moving the fastening part to the screw hole of the workpiece; and

A bolt fastening method comprising a; inserting the bolt into the screw hole and fastening the bolt.
15. The method of claim 14,

The step of fastening by inserting the bolt into the screw hole,

and matching the central axis of the bolt with the central axis of the screw hole.
15. The method of claim 14,

The step of fastening by inserting the bolt into the screw hole,

and separating the grip part from the bolt when the bolt is inserted into the screw hole at a depth greater than or equal to a set depth.