JP2671716B2 - Nut confirmation method in nut tightening system using nut runner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nut confirmation system used in a nut tightening system for tightening a workpiece while repeatedly supplying a nut to the nut runner side from the nut passing part side, and particularly to a nut tightening step after the nut passing. The present invention relates to a nut confirmation method for confirming the presence or absence of a nut housed in the socket tip of a nut runner before shifting to (1) or before shifting to the next nut delivery step after tightening the nut.

[0002]

2. Description of the Related Art Conventionally, a vehicle assembling line, for example, a tire assembling operation has been generally automated in view of a working environment and reduction of a burden on an employee. It has been disclosed. First, FIG. 5 shows the entire configuration of the tire assembling system, with the conveyor 1 for transporting the vehicle body 8 indicated by a two-dot chain line at the center interposed therebetween. Conveyors 3 for transporting tires are provided on both sides, and the tires can be transported from the start end to the end side of the conveyor 3 using a tire transport robot 3A. At the end of the conveyor 3, two pairs of tire assembling devices 2 are installed so as to be able to face the positions of the eight vehicle wheels on the conveyor 1.

As shown in FIG. 6, a tire assembling apparatus 2 includes a tire assembling robot 5 having four nut runners 10 corresponding in number to hub bolts of a tire 9, and a nut supplying apparatus 7 for supplying nuts to the four nut runners 10. Consists of 4 and 6 show the tire assembly robot 5.
As shown in the figure, the tire mounting portion 12 for mounting the tire 9 delivered from the tire positioning device 6 disposed on the end side of the conveyor 3 to the wheel on the vehicle body 8 side, and tightening the nut of the tire 9 mounted on the wheel. The four nut runners 10 are arranged so as to be movable up and down and left and right on a guide rail 13 arranged in a cross shape up and down.
It is configured to be able to rotate and move up and down by 0 degrees or a predetermined angle unit.

[0004] On the other hand, the nut supply device 7 includes a nut storage unit 20 in which a plurality of magazines for storing desired nuts are provided upright.
And a nut transfer portion 30 for fitting the nut into the socket connecting portion 40 provided at a position capable of facing the tip of the socket 101 of the nut runner 10 while repeatedly supplying the nut from the storage portion 20.

[0005] The structure of the nut transfer section 30 will be described with reference to Figs.
The nut transfer unit 30 is the nut runner 1 on the robot 5 side.
0, in other words, a socket mounting plate 31 rotatably supported by four sockets 311 arranged at the same pitch as the pitch of the hub 9 on the hub bolt side of the tire 9. A guide rail 321 for moving the mounting plate 31 toward and away from the socket connecting portion 40 and a frame 32 on which a fluid cylinder 322 is mounted. Fluid cylinder 34, base 3 for supporting them integrally
5. A fluid cylinder 3 for moving the base 35 from the nut storage section 20 side to the socket connection section 40 side or in the opposite direction.
6 and rails 37.

According to the apparatus, the frame 32 and the socket mounting plate 31 are moved down in the state where the frame 32 and the socket mounting plate 31 are laid down, and nuts are supplied into the respective sockets 311 at this position. After, nut connection part 4
It is returned to the 0 side and the socket 311 is erected so as to face the socket 401 on the connecting portion 40 side. Next, robot 5
To make the socket 101 having a hexagonal cross section on the tip side of each nut runner 10 face the axis of the socket 401 on the connecting portion 40 side, and at the same time, advance the runner in the direction of arrow F to connect the runner socket tip 101a to the connecting portion. The socket 40 is fitted into the socket 401.

The inner diameter 401 of the socket in the connecting portion 40
a has a hexagonal hole shape in cross section, and is rotatably supported on a bracket 302 which stands vertically from the front position of the base of the nut supply device 7 so that the runner socket 101 having a hexagonal cross section enters the socket 101. It rotates by a predetermined angle following the shape and is positioned at a predetermined angle position. Then, in this state, the socket mounting plate 31 located on the opposite side moves in the direction of the predetermined distance E, and the socket 311 of the mounting plate 31 is fitted into the socket 401 on the nut connecting portion 40 side, via the gears 313 and 403. Thus, the socket 311 is positioned at a predetermined angle while rotating the socket 311, and the nut 45 can be delivered to the runner 10. In this state, by operating the fluid cylinder 314 located on the rear side of the mounting plate 31, the nut located in the socket 311 of the mounting plate 31 is pushed by the rod 314a of the cylinder from the rear, so that the socket on the nut connecting portion 40 side is pushed. The runner 10 is inserted into the socket 101 on the side of the runner 10 that is fitted into the 401.

After the delivery, the runner 10 is retracted in the direction E, the runner socket 101 is pulled out, and then the runner socket 1 is moved toward the vehicle body 8 wheel.
The nut 9 is screwed into the hub bolt of the wheel to tighten the tire 9.

[0009]

Therefore, in the tire assembling apparatus 2, as shown in FIG. 7, the nut 45 (see FIG. 1) having a hexagonal cross section is transferred from the nut delivery section 30 side to the nut runner 10 side. For this purpose, smooth transfer cannot be performed unless the phase angle of the socket on the nut runner 10 side and the phase angle of the delivery side match. Therefore, in the above-mentioned prior art, the nut runner socket 10
1 and a socket 311 on the side of the nut delivery part 30 are provided with an intermediate socket 411 that is rotatably supported by a bracket 31a and into which the respective sockets 101 and 311 can be fitted, and the nut 45 of the nut 45 is inserted through the intermediate socket 411. We are trying to facilitate the transfer.

That is, to explain the configuration again, the intermediate socket 401 has a hexagonal shape on one side so that the socket 101 having a hexagonal cross section on the side of the nut runner 10 can be fitted and the socket inner diameter 401a is matched with the outer diameter of the runner socket 101.
On the other hand, the intermediate socket 401 and the socket on the nut delivery part 30 side rotatably support the socket 311 on the delivery part 30 side on the delivery part bracket 40a, and face the positioning gears 313, 403 between them. After the socket 101 on the side of the nut runner 10 is fitted into the intermediate socket 401, the intermediate socket 401 is rotated by a predetermined angle to position the two, and then the socket 311 on the side of the nut passing portion 30 is inserted into the intermediate socket 401. By being fitted into 401, the delivery side socket 311 is rotated by a predetermined angle via the gears 313 and 403, and both are positioned. As a result, the socket 311 is positioned.
The runner 1 is positioned with a transfer angle between the nut runner socket and the nut runner socket matched via the intermediate socket.
The nut 45 can be smoothly delivered to the 0 side.

However, even in the above-mentioned conventional apparatus, the nut may not always be transferred smoothly due to looseness between the socket and the nut, and in particular, the nut may not be delivered to a part of the four nut runners without being delivered. When the bolt is tightened, the hub bolt may enter the nut hole at the tip of the runner socket and the tip of the socket may idle while contacting the wheel surface. Especially, when the wheel is an aluminum wheel, the wheel surface There is a problem that the scratches will occur. Further, even if the tightening is performed with the idle rotation as described above, since the predetermined tightening torque is not provided, the tightening time is unnecessarily lengthened without the tightening OK, which adversely affects other normal nuts. The problem occurs.

For this reason, it is possible to check the presence or absence of the nut when tightening the nut. However, with such a configuration, it may be the absence of the nut in the runner socket that occurs when the nut is delivered, or the nut may be tightened after the nut is delivered. It is only possible to determine if it was caused by a fall. In particular, if it occurs during nut delivery, the nut will be left in the socket on the nut delivery side, and in this state, the nut will remain in the socket even when trying to deliver the next nut from the nut feeder side. Therefore, the nut cannot be delivered smoothly, and the tightening failure continues. Therefore, if the nut delivery is defective, it is necessary to remove the remaining nuts on the nut delivery side socket, but if there is no nut in the runner socket, it is not possible to determine whether it occurred at the time of nut delivery or the cause of nut drop. It is difficult to remove the residual nuts.

Further, the above problem may occur even when the nut is tightened. That is, when foreign matter adheres to the hub bolt side or the nut screw portion, a tightening failure may occur and the nut may remain in the runner socket 101. Even if such a nut remains, the next nut is delivered. Since the nut remains in the socket, the nut cannot be delivered smoothly, and the tightening failure continues.

In view of the above-mentioned drawbacks of the prior art, the present invention immediately detects the case where the nut is not smoothly transferred into the socket of the nut runner at the time of delivering the nut and solves the problem at the time of tightening work. It is a thing. Another object of the present invention is to provide a nut confirming system which has a simple structure and can surely detect the presence or absence of the nut. Another object of the present invention is to detect the nut before the next nut is delivered even if the nut is left in the socket of the nut runner due to the insufficient tightening, and to solve various problems caused by the nut remaining. It is to provide a nut confirmation method for solving the problem.

[0015]

SUMMARY OF THE INVENTION In order to achieve such a technical object, the present invention provides a nut tightening system for tightening a work while repeatedly supplying a nut to a nut runner side from a nut passing part side, after a nut delivery. Before moving to the nut tightening process, or before moving to the next nut delivery process after tightening the nut, appropriately abut the socket tip of the nut runner with the abutment plate, and by the corresponding contact, the inside of the socket In addition, we propose a nut confirmation method characterized in that the sensor detects the changed portion that changes due to the presence or absence of a nut and confirms the presence or absence of the nut. It is to be noted that the change depending on the presence or absence of a nut in the socket depending on the contact is, for example, when the nut is housed in the socket tip and the nut is configured to project about 5 to 10 mm from the socket tip. In addition, the stroke amount of the nut runner rod when contacting the contact plate changes depending on the presence or absence of a nut,
By detecting the stroke difference with a dog and a proximity switch, it is possible to easily confirm the presence or absence of the nut. If a spot-shaped piezoelectric sensor or the like is arranged at a position where the socket tip of the nut runner of the abutment plate abuts, and the nut at the socket tip presses the piezoelectric sensor, the abutment of the socket tip causes The presence or absence of a nut in the socket can be easily detected by a piezoelectric sensor.

[0016]

According to such a technical means, the presence or absence of the nut can be easily confirmed in a short time only by bringing the socket tip portion into contact with the contact plate after delivering the nut. Therefore, if some of the sockets do not have nuts at the time of confirmation, it is possible to remove the nuts stored in the other nut runners that perform simultaneous tightening, as shown in the examples described later. It is possible to eliminate the risk of tightening the nut without delivering the nut to a part of the nut runner, and it is possible to eliminate various defects that occur when tightening the nut. In addition, since the presence or absence of a nut can be checked immediately after the nut is delivered, it is possible to easily confirm a defective nut delivery without the above-mentioned nut. By removing the remaining nut on the nut delivery side, it is possible to always deliver the nut smoothly. Good quality, no defective delivery or tight fastening will continue.

Even if a tightening failure occurs when tightening the nut, the nut may remain in the runner socket. Even in such a case, the presence or absence of the nut can be confirmed before delivering the next nut. Then, by removing the nut when it remains, it is possible to eliminate the risk of carrying out the next nut delivery while the nut remains, and it is possible to deliver the nut smoothly.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention, but are merely illustrative examples. Not just. FIG.
Is a contact plate for confirming the presence or absence of the nut 45 in the runner socket 101 according to the embodiment of the present invention, and the presence or absence of the nut is confirmed in the overall configuration diagram of the device incorporating the nut discarding mechanism (hereinafter referred to as the socket pressing plate 60). Show the situation. FIG. 2 shows a situation where the nuts are discarded. FIG. 3 is a configuration diagram of a main part of FIG. First, to explain the nut presence confirmation system,
In FIG. 1, this apparatus is provided with a nut discarding mechanism on the upper side of the base 53, and a socket pressing plate 60 for confirming the presence or absence of the nut 45 on the front surface of the base 53. The pressing plate 60 is made of hardened steel so as not to be worn by repeated impact of the socket tip 101a, and is vertically installed to prevent the positional error when the socket 101 is contacted, and the flatness of the surface is maintained. I have put it out.

The socket tip 10 on the nut runner 10 side
The nut housing portion 1a has its inner diameter set so that when the nut 45 is housed in the nut 45, the nut 45 projects about 5 to 10 mm from the socket tip 101a, and the runner rod 102 moves forward and backward together with the socket 101 at a predetermined position. Further, the dog 103 is provided, and the proximity sensor 18 is provided at a position facing the rod 102 such as the bracket 103 of the robot 5 in the vicinity of the dog 103.

As a result, when the cap nut 45 is housed in the socket tip 101a, since the nut 45 projects from the socket tip 101a, the socket tip 101a of the nut runner 10 on the robot 5 side is attached to the contact plate. When abutting, the stroke stroke of the runner rod 102 differs depending on the presence or absence of the cap nut 45, and the stroke difference is provided between the dog 103 and the rod 10.
The presence or absence of the cap nut 45 can be easily grasped by performing detection by using the proximity sensor 18 or the like provided at a position that faces 2.

On the other hand, as shown in FIGS. 2 (A) and 3, the nut dumping mechanism includes a magnetized body 50 in which magnets are embedded at a pitch interval corresponding to the pitch interval of the nut runner 10 of the robot 5, and a fluid cylinder 54. The nut discarding plate 51 that vertically descends along the surface of the magnetized body 50 by the lifting operation.
And a nut receiving box 52 for receiving the cap nut 45 separated from the magnetized position of the magnetized body 50 by the discard plate 51.

The magnetized body 50 has a main body made of, for example, a non-magnetic material, which is mounted on the front surface side of a mounting plate 54 which stands vertically on a base 53, and has a pitch interval corresponding to the pitch interval of the nut runner 10. Four holes 561 are formed from the front surface side toward the mounting plate side 54, and a bush 57 made of a hardened magnetic material is fitted and fixed in the hole 561, and the rubber 58 and the cobalt magnet 59 are housed in the bush 57.
Are sequentially inserted and fixed with an adhesive or the like. At this time, in order to prevent the nut 59 from coming into contact with the surface of the magnet 59 and damaging the magnet 59, the magnet 59 is positioned slightly behind the front end surface of the bush 57. As a result, since the nut 45 does not directly contact the magnet 59, damage to the magnet 59 can be prevented and
Since the bush 57 is hardened, it will not be worn even if the nut 45 collides with it. Further, the rubber 58 located on the back side of the magnet 59 functions as a demagnetizing material for preventing the propagation of magnetic force to the mounting plate 54 side, and also has a function as a cushioning effect when the nut 45 is in contact. You

The nut discarding plate 51 is preferably made of a non-magnetic material, and as shown in FIG. 2B, a pair of circular holes 511 slightly larger than the outer diameter of the cap nut 45 and a pair of holes formed at the lower end side. The concave portions 512 of the fluid cylinder 5 are formed with a pitch interval corresponding to the pitch interval of the nut runner 10.
4, the hole on the side of the magnetized body 50 and the hole and recess 51
The two axes are configured so that they can coincide with each other. The device is not particularly limited as long as it is a position facing the socket tip 101a of the nut runner 10 by the orbit of the tire mounting robot 5, but, for example, as shown in FIG. 4, a position above the socket connecting portion 40 of the nut supply device 7. Further, it is preferable to dispose the nut runner 10 so as to face the socket tip 101a of the nut runner 10.

Next, the operation of this embodiment will be described. The robot 5, which has received the cap nut 45 from the nut passing portion 30 side through the connecting portion 40, moves up to the position of the socket pressing plate 60, and then advances the rod 102 to move the runner socket tip 101a to the pressing plate. The dogs 10 are contacted with each other to determine whether or not the cap nuts 45 are delivered to the respective socket tips 101a.
3 and the proximity sensor 18, if all the runners 10 have nuts housed therein, the runner rod 10
After retracting 2 to the rear, the vehicle body 8 is moved to the wheel side as it is, and the cap nut 45 in the runner socket 101 is screwed onto the hub bolt of the wheel to tighten the tire 9.

On the other hand, the cap nut 45 of one of the runners 10
If there is not, after the runner rod 102 is retracted rearward, the robot 5 is reversely moved up until the axis of each runner 10 is aligned with the four holes of the magnetized body 50.
The runner 10 is extended until the runner socket tip 101a comes into contact with the end faces of the bushes 57 of the four holes. As a result, the nut 45 is attracted to the end surface of the bush 57 by utilizing the magnetic force of the magnet 59 located on the inner side of the bush 57. In this state, the fluid cylinder 54 is raised, and the pair of circular holes 511 and the pair of recesses 512 of the nut discarding plate 51 have the same axial center as the hole on the magnetized body 50 side. Will be loosely fitted in the pair of circular holes 511 and the pair of recesses 512.

Next, the nut 45 is removed from the socket tip 101a by retracting the runner rod 102, and in this state, the nut 45 adsorbed on the end surface of the bush 57 is lowered by lowering the rod of the fluid cylinder 54. The discard plate 51 descends, and following this, the nut loosely fitted in the pair of circular holes 511 and the pair of concave portions 512 is forced downward while being dragged downward by the circular holes 511 and the upper ends of the concave portions 512. Bush 57
The magnet 59 is released from the end surface, the attraction force of the magnet 59 is released, and the nut 59 is stored in the lower nut receiving box 52 by gravity. Then, after that, the nuts left on the side of the nut delivering section are removed, and the nut delivering operation is performed again.

On the other hand, after completion of the nut tightening step, the robot 5 re-circulates the robot 5 to bring the socket tip 101a into contact with the socket pressing plate 60 and leave the cap nut 45 at the socket tip 101a. The dog 103 and the proximity sensor 18 are used to determine whether or not the runner rod 10 has been left.
After retracting 2 to the rear, the robot 5 is lowered as it is to move to the socket connecting portion 40 side, and the above-mentioned predetermined nut 45 is delivered.

On the other hand, when the cap nut 45 is left in any of the runners, the runner rod 102 is retracted rearward, and then the robot 5 is reversed, and the axis of each runner 10 is magnetized. Then, the nut is thrown away and the above-mentioned operation is carried out. Thereafter, the robot 5 is lowered to move to the socket connecting portion 40 side, and the above-mentioned next-order nut 45 transfer operation is performed. As a result, the nuts can always be delivered with certainty, and tightening failure etc. will occur. Although the present embodiment has described the device in which the socket pressing plate 60 and the nut discarding mechanism are integrally assembled, as shown in FIG. 6, only the socket pressing plate 60 is erected on the socket connecting portion 40 to check the nut. You may make it do only.

[0029]

As described above, according to the present invention, when the nut is not smoothly transferred into the socket of the nut runner at the time of delivering the nut, this can be immediately detected and the problem at the time of tightening work can be solved. . Further, according to the present invention, since only the contact plate and the sensor for detecting a change due to the presence or absence of the nut in the socket are sufficient, the presence or absence of the nut can be detected with a simple structure.
Further, according to the present invention, even when a nut is left in the socket of the nut runner due to a tightening failure, this is detected before the next nut is delivered, and various problems caused by the left nut are solved. I can do things. And so on.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an apparatus incorporating a nut discarding mechanism and a nut confirmation mechanism according to an embodiment of the present invention, and mainly shows the operation of the nut confirmation mechanism.

2 is an overall configuration diagram showing a mechanism on the side of the nut discarding device of FIG. 1. FIG.

FIG. 3 shows an enlarged view of FIG.

FIG. 4 is a partially omitted schematic diagram showing a configuration of a main part of a tire tightening system incorporating the device of FIG.

FIG. 5 is a schematic view showing the entire configuration of a tire tightening system.

FIG. 6 is a partially omitted schematic view showing a configuration of a main part of the tire tightening system shown in FIG. 5;

FIG. 7 is a detailed front view of a nut transfer section.

[Explanation of symbols]

 7 Nut Supply Device 30 Nut Transfer Section 5 Robot 10 Nutrunner 101 Socket 9 Workpiece (Tire) 60 Contact Plate (Socket Pressing Plate) 18 Proximity Sensor 103 Dog

Claims (1)

(57) [Claims] 1. A nut tightening system for tightening a workpiece while repeatedly supplying a nut to the nut runner side from the nut passing part side, and after transferring the nut into the socket or after tightening the nut, until the next step. During the above, the tip of the socket of the nut runner is appropriately brought into contact with an abutment plate, and the corresponding contact is detected by a sensor to detect a changed portion that changes due to the presence or absence of the nut in the socket, and the presence or absence of the nut is confirmed. Nut confirmation system characterized by