JPS649134B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nut runner for tightening a nut such as a hub nut for an automobile.

For example, when tightening vehicle hub nuts on a vehicle assembly mass production line, a nut runner with multiple sockets corresponding to the hub nuts is used to tighten many hub nuts at the same time in order to improve work efficiency. Since it was common for one type of vehicle to be assembled on one vehicle assembly line, one type of nut runner was generally installed on one assembly line. Therefore, if vehicle models with different numbers and locations of hub bolts (i.e. pitch circle radius) are put on the same assembly line, the existing nut runners will not be compatible with the different vehicle models, so the hub nuts for that vehicle must be tightened one by one. Therefore, in the past, when car models with different numbers of hub bolts and pitch circle radii were mixedly produced on the same assembly line, the number of hub bolts and pitch circle radii of each car type had different sockets that matched the number of hub bolts and pitch circle radius. The multi-spindle nut runner was installed on the assembly line, and workers used the nut runner depending on the type of vehicle coming down the assembly line. However, if, for example, two types of nut runners are installed in the same work area, the space will need to be increased accordingly, and if the space is not particularly expanded, when one nut runner is used, the other nut runner is Work is often obstructed, and this tendency becomes especially noticeable when work spaces are consolidated.Furthermore, it is common for vehicles to be assembled while running on a line, but when multiple types of vehicles are assembled, When installing two nut runners in the same work area, it is recommended to run the nut runner in synchronization with the vehicles on the line and perform the tightening work automatically or semi-automatically, in terms of space and equipment configuration. There were some problems, such as making it extremely difficult.

This invention was made in view of the above circumstances, and involves changing the pitch circle radius of a socket fitted to a nut so that it matches the pitch circle radius of a plurality of nuts to be tightened, and changing the number of sockets at the same time. The purpose of this invention is to provide a nut runner that can perform the following functions. The feature of this invention is that the driven shaft, which has a socket at its tip, is eccentrically attached to the rotary drive shaft through a gear in a gear box that is attached to the rotary drive shaft so as to be rotatable at a predetermined angle. By engaging the gear box and rotating the gear box by a predetermined angle by a drive device, the driven shaft, that is, the socket, revolves around the rotary drive shaft. by providing a rotary drive shaft, and moving said socket between a position on the circumference that includes the socket of the other rotary drive shaft and a position on the circumference that does not include the socket of the other rotary drive shaft, The point is that the pitch circle radius for arranging the sockets and the number of sockets are configured to be changed.

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic front view showing one embodiment of the present invention, and FIG. 2 is a partially omitted cross-sectional view, in which a front plate 2 is attached to the front side of a main body 1 at a predetermined interval. Between the main body 1 and the front plate 2, there are five rotary drive shafts 3a, 3.
b, 3c, 3d, 3e are provided, and these rotary drive shafts 3a, 3e are connected to a rotary drive device (not shown) such as an air motor provided in the main body 1.
Four rotary drive shafts 3a, ...3d of the rotary drive shafts 3a, ...3e pass through the front plate 2. Gear box 4 provided for free rotation
a, 4b, 4c, 4d, and
The gear boxes 4a, 4d are rotatably engaged, and the remaining rotational drive shaft 3e is
The front plate 2 is configured to be expandable and contractible.
It penetrates through and is rotatably supported with respect to the front plate 2.

The gear boxes 4a,...4d are connected to the rotational drive shaft 3.
The gear boxes 4a, 4d are rotatable around a, 3d, and eccentric to the rotation drive shafts 3a, 3d,
Driven shafts 6a, 6b, 6c, 6d protruding forward are rotatably mounted, and these driven shafts 6a, . . .
...6d and the corresponding rotational drive shafts 3a, ...
...3d is engaged with the gears 7a in the gear boxes 4a, . (not shown)
a, 8b, 8c, 8d are provided, and therefore these sockets 8a, . . . 8d are rotated by the rotary drive shafts 3a, . ...4d rotates around the rotary drive shafts 3a, ...3d, thereby revolving around the rotary drive shafts 3a, ..., 3d.

Further, each of the gear boxes 4a, . , an air cylinder 10a serving as a driving device for rotating the gear boxes 4a, 4b is provided between the cylindrical portions of one pair of gear boxes 4a, 4b.
are provided, and the other pair of gear boxes 4c, 4
Between the cylindrical portions of d, another air cylinder 10b
are similarly provided. In other words, brackets 11a and 11b are provided on each cylindrical portion of the pair of gear boxes 4a and 4b, respectively, and the tip of the rod of the air cylinder 10a is attached to one bracket 11a, and the other bracket is attached to the tip of the rod of the air cylinder 10a. The rear end portion of the air cylinder 10a is attached to 11b. Further, the other pair of gear boxes 4c,
Brackets 11c and 11d are provided on each of the cylindrical parts 4d, and one of the brackets 1
The tip of the rod of the air cylinder 10b is attached to the bracket 1c, and the rear end of the air cylinder 10b is attached to the other bracket 11d. Therefore, each gear box 4a,...4d
is configured to rotate around the rotary drive shafts 3a, . . . 3d by operating each of the air cylinders 10a, 10b to change their overall length.

Further, stopper plates 12a, 12b, 12c, 12d are fixed to the cylindrical portions of the respective gear boxes 4a, 4d, and the stopper plates 12a, 12d are brought into contact with the back surface of the front plate 2. Stopper pins 13a, 13b are provided to prevent rotation of each gear box 4a, 4d,
These stopper plates 12a, 12d and stopper pins 13a, 13b regulate the rotation angle of each gear box 4a, 4d, that is, the range of revolution of the sockets 8a, 8d. There is.

Further, on the front side of the front plate 2 of each gear box 4a, 4d, a positioning plate 14a,
14b, 14c, 14d are provided, and among these positioning plates 14a,...14d, gear box 4a
The positioning plates 14a and 14d of the gear boxes 4a and 4d always overlap when the gear boxes 4a and 4d are rotated to the corresponding limit positions, and the positioning plates 14a and 14d of the respective positioning plates 14a and 14d overlap each other. Small holes 16a and 16d for inserting positioning pins 15a are formed at the locations.
Further, the other positioning plates 14b, 14c among the positioning plates 14a, 14d always overlap when the gear boxes 4b, 4c in which they are installed are rotated to their corresponding limit positions. Small holes 16b and 16c for inserting another positioning pin 15b are formed in the positions where the positioning plates 14b and 14c overlap with each other.

The positioning pins 15a, 15b pass through the front plate 2 and are inserted into the small holes 16a, 16d and 1.
6b, 16c, and these positioning pins 15a, 15b are inserted into the main body 1.
It is attached via a bracket 18 to the tip of the rod 17a of the positioning air cylinder 17 provided inside.
By advancing a, it penetrates the front plate 2 and is inserted into each of the small holes 16a, 16d,
As a result, each positioning plate 14a, 14d, that is, each gear box 4a, 4d, is positioned, and by retracting the rod 17a, each small hole 16a, 15b is inserted into a positioning pin 15a, 15b.
......16d, and as a result, each positioning plate 14a, ...14d, that is, each gear box 4a,
......It is designed to be able to rotate 4d.

On the other hand, the telescopic rotary drive shaft 3e
As shown in the figure, a rotating shaft 19a is attached to the output shaft of a rotary drive device provided in the main body 1, and a cylindrical shaft is fitted to the rotating shaft 19a so as to be non-rotatable and slidable back and forth. 19b, the cylindrical shaft 19b is movable back and forth and rotatably supported by a guide sleeve 20 protruding from the front plate 2, and a socket 8e is provided at the tip of the cylindrical shaft 19b. It is provided. An annular body 21 for retracting the cylindrical shaft 19b is loosely fitted on the outer periphery of the cylindrical shaft 19b, and the annular body 21 is attached to the rod 1 of the air cylinder 17.
It is connected to a bracket 18 attached to 7a. Further, a coil spring 22 is arranged between the annular body 21 and the tip of the cylindrical shaft 19b.
In the case where the rotary drive shaft 3e is locked in a retracted state, that is, in a shortened state as described later, the annular body 21 is compressed while the coil spring 22 is compressed.
The ring body 21 moves forward and backward, and in the unlocked state, by moving the annular body 21 forward,
The cylindrical shaft 19b is pushed by the coil spring 22 and protrudes forward.

Here, the structure for locking the rotary drive shaft 3e in the shortened state will be explained. A slit 23 is formed in the guide sleeve 20,
Further, stopper plates 24c and 24d are provided on the gear boxes 4c and 4d located near the guide sleeve 20, and stopper plates 24c and 24d are provided which fit into the slit 23 when the gear boxes 4c and 4d are rotated in a predetermined direction. An annular groove 25 is formed at a predetermined location at the tip of the shaft 19b, with which the stopper plates 24c and 24d engage. Therefore, the rotary drive shaft 3e causes the cylindrical shaft 19b to move backward through the annular body 21 with the air cylinder 17, and in this state rotates the gear boxes 4c, 4d to close the stopper plates 24c, 2.
4d into the slit 23,
By engaging the stopper plates 24c and 24d with the annular groove 25, the stopper plates 24c and 24d are held in the shortened state. That is, the air cylinder 17 and the annular body 21 constitute a longitudinal movement mechanism.

Next, to explain the operation of the nut runner constructed as above, Fig. 1 shows a state in which the number of axes is set to five, and in this state, the gear box 4 is
The annular groove 25 formed in the stopper plates 24c and 24d provided at c and 4d and the telescopic rotary drive shaft 3e.
Since the engagement with the rotary drive shaft 3e is disengaged, the rotary drive shaft 3e extends to the most extreme position, and as a result, the socket 8e attached to the rotary drive shaft 3e is connected to the other sockets 8a, . . .
It protrudes to the same position as 8d. Furthermore, these five sockets 8a, . . . 8e are located at equal intervals on the circumference of a predetermined pitch circle radius d, and therefore these sockets 8a, . . . 8e are located at the vertices of a regular pentagon. This means that Note that positioning pins 15 are provided in the small holes formed in the positioning plates 14a, 14d and aligned on the same axis.
a, 15b are inserted, and as a result, each of the bearing boxes 4a, . . . 4d is locked in the state shown in FIG. In this state, the rotational drive shaft 3a,...
...If you rotate 3e, all sockets 8a,
......Since 8e rotates in the same direction, five nuts can be tightened at the same time.

To change the number of axes from the aforementioned five axes to four axes, proceed as follows. That is, first, the rod 17a of the air cylinder 17 is moved backward, and the positioning pins 15a, 15b are attached to the positioning plate 14.
Pull it out from the small hole formed in a, ...14d.
In this case, the annular body 21 is connected to the air cylinder 1
7, the cylindrical shaft 19b constituting the telescopic rotary drive shaft 3e is retracted by the annular body 21, and at the same time the socket 8e is retracted. After the cylindrical shaft 19b has retreated to the retracted position, when the rod of the air cylinder 10a placed between one pair of gear boxes 4a and 4b is retreated into the cylinder, the gear boxes 4a and 4b are moved as shown in FIG. When the air cylinder 10b is rotated in the direction of the arrow and the rod of the air cylinder 10b disposed between the other pair of gear boxes 4c and 4d is advanced, the gear box 4
c and 4d rotate in the direction of the arrow shown in FIG. As a result, the stopper plates 12a, 12d attached to the respective gear boxes 4a, 4d come into contact with the stopper pins 13a, 13b and are prevented from rotating, thereby locking the respective sockets 8a, 8d. moves from the position shown by the chain line in FIG. 3 to the position shown by the solid line, and the pitch circle radius D increases, so that each socket 8a, . . . 8d is located at the vertex of the square. Moreover, the gear box 4a,...
... 4d, the other pair of gear boxes 4c, 4d rotates as described above, so that the gear boxes 4c, 4d,
The stopper plates 24c and 24d attached to the cylindrical shaft 19b enter the slit 23 of the guide sleeve 20 and engage with the annular groove 25 of the cylindrical shaft 19b, resulting in the forward movement of the cylindrical shaft 19b, that is, the rotational drive shaft 3.
e is prevented from extending, and the socket 8e attached to the rotary drive shaft 3e is locked in the retracted position. Also, as a result of each gear box 4a, 4d rotating as described above, the other small holes in the positioning plates 14a, 14d attached to each gear box 4a, 4d are aligned on the same axis. When the positioning pins 15a, 15b are advanced and inserted into the small holes, the respective gear boxes 4a, . . . 4d, that is, the sockets 8a, . . . 8d, are positioned and fixed. In this case, the annular body 21 moves forward together with the positioning pins 15a and 15b;
Since it is only loosely fitted into the cylindrical shaft 19b, the coil spring 22 is only compressed and the cylindrical shaft 19b does not move forward.

That is, if the operation is performed as described above, one socket 8e will be in a state where it is largely set back from the other sockets 8a, 8d, so the nut runner is brought into contact with a predetermined workpiece in order to tighten the appropriate nut. If the retracted socket 8e
does not interfere with the work, and therefore the nut runner set as described above functions as a four-axis nut runner.

Note that when converting from 4 axes to 5 axes, the operation described above may be reversed.

Furthermore, in the above explanation, each operation was explained individually, but the above series of operations can also be performed automatically.
......Rotation of 4d and positioning pins 15a, 15b
A switch is appropriately provided to detect the completion of the forward and backward movement of the air cylinders 10a, 10a, etc.
The valves controlling 10b, 17, etc. may be switched by the output signal of the switch.

Furthermore, although the above embodiment is configured to be able to convert into 5 axes and 4 axes, it may be configured to convert into an appropriate number of axes such as 2 and 3 axes, or 6 and 7 axes.

Furthermore, it goes without saying that the nut runner of the present invention can be used not only for tightening nuts, but also for loosening nuts.

As is clear from the above description, according to the present invention, the driven shaft having a socket at its tip is eccentrically attached to the rotary drive shaft via a gear in a gear box rotatably attached to the rotary drive shaft. The gear box is rotated by a predetermined angle by a drive device, thereby causing the driven shaft, that is, the socket, to revolve around the rotary drive shaft. Providing another rotary drive shaft, and moving each of the sockets to a position on the circumference that includes the socket of the other rotary drive shaft and a position on the circumference that does not include the socket of the other rotary drive shaft. Since the structure is configured to change the radius of the pitch circle in which the sockets are arranged and the number of sockets, the number of nuts in the object to be tightened and the radius of the pitch circle in which the nuts are arranged are as follows.
Even if the pitch circle radius is different from the previous tightening work, it is possible to tighten the nut by changing the number and position of the sockets to match the number of nuts and the pitch circle radius of the target object. Therefore, according to the nut runner of the present invention, even when vehicles with different numbers of hub nuts and pitch circle radii are run on the same production line, the hub nuts of each vehicle can be tightened with one nut runner. This not only reduces the number of nut runners required and prevents a rise in equipment costs, but also makes it possible to take up a wider work space, which in turn makes the work easier.

[Brief explanation of the drawing]

FIG. 1 is a simplified front view showing one embodiment of the present invention, FIG. 2 is a partially simplified longitudinal sectional side view, and FIG. 3 is an explanatory diagram showing the position of a socket. 3a, 3b, 3c, 3d, 3e... Rotation drive shaft, 4a, 4b, 4c, 4d... Gear box, 6a,
6b, 6c, 6d... Driven shaft, 7a... Gear, 8
a, 8b, 8c, 8d, 8e... socket, 10
a, 10b...Air cylinder, 19a... Rotating shaft, 19b... Cylindrical shaft, 17... Air cylinder, 21... Annular body, 24c, 24d... Stopper plate, D, d... Pitch circle radius.

Claims (1)

[Claims] 1 A gear box is attached to each of a plurality of rotational drive shafts arranged parallel to each other so as to be rotatable by a predetermined angle about the axis of the rotational drive shaft, and the gear box is eccentric to the rotational drive shaft. A driven shaft having a socket at its tip that fits into the nut to be tightened is mounted in parallel to the rotary drive shaft, and the driven shaft is connected to the rotary drive shaft via a gear provided in the gear box. Further, a drive device is provided for rotating the gear box by a predetermined angle around the rotation drive shaft, and another rotation drive shaft is provided that has a socket at its tip and is extendable and retractable in a direction parallel to the driven shaft. At the same time, a forward and backward movement mechanism is provided for extending and contracting the other rotary drive shaft between a forward position where the socket at the tip thereof is flush with the socket and a retracted position at which the shaft is retracted from the forward position. By rotating the gear box, the socket of each driven shaft is moved from a circumference of a predetermined radius that includes the socket of the other rotary drive shaft to a circumference of another radius that does not include the socket of the other rotary drive shaft. A nut runner capable of changing the radius of a pit circle, characterized in that the nut runner is configured to move on the circumference.