JP4169857B2 - Nut runner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a nut runner that tightens a plurality of types of bolts having the same nominal size with a single type of socket.
[0002]
[Prior art]
As an automatic tightening device that automatically tightens a plurality of bolts at a plurality of tightening coordinates with a nut runner, (1) all bolts are tightened in turn with a single nut runner, and (2) a plurality of bolts There are the one that tightens bolts in turn with a smaller number of nut runners, and the one that tightens each bolt simultaneously using the same number of nut runners as (3) multiple bolts. In the case of (1) and (2), a plurality of bolts having bolt heads of the same nominal size that are fitted into the sockets of a single nut runner are used. In the case of (3), the nominal dimensions of the heads of the bolts may not be the same, but usually using nut runners with the same type of socket using bolts having the same nominal dimensions of the head. I try to tighten it.
[0003]
Also, if there are multiple types of multiple bolts installed at multiple tightening coordinates and the final tightening torque or final tightening angle differs for each type, the tightening coordinates at which each bolt is installed Every time, the data of the final tightening torque or the final tightening angle is programmed in the nut runner drive control system. For example, there are two types of bolts of the first to fourth tightening coordinates, A bolt and B bolt, the first and third tightening coordinates are A bolt, and the second and fourth tightening coordinates are B. In the case where the bolts of the two types are tightened in turn with different tightening torques for each bolt type using a single nut runner, the following procedure is performed.
[0004]
The nut runner drive control system is programmed with the tightening torque data Da at the first and third tightening coordinates and the tightening torque data Db at the second and fourth tightening coordinates. Using a nut runner, tighten the bolt with the first tightening coordinate with the tightening torque of data Da. Next, the bolt of the second tightening coordinate is tightened with the tightening torque of the data Db with the nut runner, then the bolt of the third tightening coordinate is tightened with the tightening torque of the data Da, and finally the fourth tightening coordinate. Tighten the bolt with the tightening torque of data Db. Such a bolting operation based on data programmed in each of the plurality of tightening coordinates is a reliable operation performed on the assumption that the type of bolt at each tightening coordinate is not wrong.
[0005]
Also, when there are multiple types of bolts with multiple tightening coordinates and each bolt is tightened simultaneously with different tightening torques for each type with multiple nut runners, the final tightening torque at each of the multiple tightening coordinates is It is programmed in the drive control system of each nut runner. Also in this case, the operation is performed with a reliable operation of simultaneously tightening the bolts with the respective nut runners on the assumption that the type of the bolt at each tightening coordinate is not wrong.
[0006]
[Problems to be solved by the invention]
When tightening multiple types of bolts installed at multiple tightening coordinates as described above with the reliable operation of the nut runner, the type of bolt at any tightening coordinate is different from the predetermined type Therefore, there is a problem that the bolts of the tightening coordinates are tightened at a tightening torque or a tightening angle set to different types of bolts. Such a failure can be detected by the nut runner drive control system if the tightening torque or tightening angle differs greatly depending on the bolt type, but it is detected after the bolt is tightened. Troubles such as bolt breakage due to unavoidable cannot be avoided.
[0007]
An object of the present invention is to provide a highly reliable nut runner that can easily confirm the types of a plurality of bolts before tightening.
[0008]
[Means for Solving the Problems]
The invention according to claim 1 is a nut runner in which a socket provided at a tip is fitted to a bolt head to be tightened and a flanged bolt is fastened. The nut runner is fitted into the socket so as to be relatively movable in the socket axial direction. The bolt heads are in contact with the flange of the bolt head with a gap interposed between the socket top surface and the bolt head, and the bolt heads have different types of axial shapes. Bolt shape detecting means whose relative position is displaced with respect to the socket for each type, and a bolt for detecting the type of bolt based on the axial shape of the bolt head from the displacement of the relative position of the bolt shape detecting means with respect to the socket immediately before bolting It is characterized by comprising type detection means.
[0009]
Here, the plurality of types of bolts having different axial shapes of the bolt heads are bolts that are divided by the stepwise difference in thickness (axial height) of the bolt heads, or the bolt heads have the same thickness. The bolts can be divided according to whether the top surface of the head is flat or there is a recess (bolt type groove, bolt fastening groove, etc.) in the center of the top surface, and the depth of the recess is stepwise Bolts etc. that can be divided by different. The displacement of the relative position of the bolt shape detection means with respect to the socket is made different according to the shape of the bolt head, and the difference in displacement is detected by the bolt type detection means. The type is detected. Thus, by detecting the bolt type immediately before the bolt tightening, if the detected bolt type is appropriate, the nut runner drive control system starts the bolt tightening operation. Confirmation operations such as interrupting and handling can be performed.
[0010]
The invention of claim 2 is characterized in that the bolt shape detecting means has a shape detecting shaft whose relative position with respect to the socket is displaced for each of different axial shapes of the bolt heads fitted in the socket. Such a shape detection shaft is slidably inserted into the socket, and is in elastic contact with the top surface of the bolt head via a spring material such as a coil spring.
[0011]
The invention of claim 3 is characterized in that the bolt type detecting means has a photoelectric sensor for optically detecting a displacement of a relative position of the bolt shape detecting means with respect to the socket. Such a photoelectric sensor is fixed to a socket holder or the like that detachably supports the socket, and detects the displacement of the relative position of the bolt shape detection means with respect to the socket stepwise by an electric signal.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIG. 1 to FIG. 4, which is a socket 20 that is detachably attached to a socket holder 12 of a single-unit nut runner 10 and is installed at a specific tightening coordinate. A plurality of, for example, two types of bolts 1a and 1b are automatically tightened.
[0013]
The left and right halves of the two types of bolts 1a and 1b shown in FIGS. 1 to 4 are illustrated. The top half of the head 2a of the bolt 1a in the left half of the drawing is a flat surface, and the right half of the cross section is shown in FIG. The bolt 1b shown in the figure has a recess 3 having a predetermined depth t at the center of the top surface of the head 2b. The heads 2a and 2b of the two types of bolts 1a and 1b are hexagonal heads having the same nominal size and thickness that are fitted into the common socket 20. 1 and 2 show the in-situ state before bolting, and FIGS. 3 and 4 show the operating state immediately before bolting. The left half of FIGS. 3 and 4 in this operating state is one type. The right half corresponds to the other one type of bolt 1b.
[0014]
A cylindrical socket holder 12 is connected downward to a lower end portion of an output shaft 11 that protrudes downward from a nut runner 10 that is driven up and down. The upper part of the cylindrical socket 20 is fitted in the lower part of the socket holder 12 so as to be detachable in the axial direction. A plurality of engagement balls 13 are embedded in the cylindrical lower side wall of the socket holder 12, and the socket detachable cylinder 14 is fitted on the outer periphery of the lower side wall so as to be slidable in the axial direction. The socket 20 is detached from the socket holder 12 by moving the socket detachable cylinder 14 up and down with respect to the socket holder 12 and operating the engagement and removal of the engagement ball 13 and the socket 20.
[0015]
The socket 20 is a cylindrical body, and has a hexagonal hole 21 into which one of two types of bolt heads 2a, 2b is fitted at the lower end. A bolt shape detecting means 30 for detecting a difference in axial dimension between the heads 2a and 2b of the two types of bolts 1a and 1b at the socket 20 and the socket holder 12, and a socket 20 of the bolt shape detecting means 30 Bolt type detecting means 40 for detecting the types of the two types of bolts 1a and 1b based on the displacement of the relative position with respect to is installed.
[0016]
The bolt shape detection means 30 includes, for example, a shape detection shaft 31 slidably inserted in the socket holder 12 along the central axis of the socket holder 12 in the axial direction (vertical direction), and a tip end side of the shape detection shaft 31. A coil-shaped spring material 32 that constantly biases the elastic force in a direction in which the socket holder 12 protrudes from the tip of the socket holder 12 is provided. The shape detection shaft 31 has a length that penetrates the center of the lower part of the socket holder 12. When the socket 20 is fitted into the socket holder 12, the shape detection shaft 31 slidably penetrates the socket 20 to form the shape. The tip of the detection shaft 31 protrudes from the center of the top surface of the hexagonal hole 21.
[0017]
The upper end portion of the shape detection shaft 31 reaches the cylindrical upper portion of the socket holder 12, and the central portion of the horizontal shaft 33 is fixed to the upper end portion in the orthogonal direction, and both end portions of the horizontal shaft 33 are the upper side walls of the socket holder 12. The guide hole 34 formed in is penetrated. A spring material 32 is disposed in a compressed state between the horizontal shaft 33 and the tip of the output shaft 11, and elastic force is constantly applied to the shape detection shaft 31 via the horizontal shaft 33. 1 and 2, the shape detection shaft 31 is held stationary with the spring material 32 elastically locking the horizontal shaft 33 to the lower end surface of the guide hole 34. At this time, the lower end portion of the shape detection shaft 31 protrudes from the center of the top surface of the hexagon hole 21 of the socket 20 with a protrusion length that is approximately half the depth of the hexagon hole 21.
[0018]
The bolt type detection means 40 detects the displacement of the relative position in the axial direction of the shape detection shaft 31 with respect to the socket 20 fitted to the socket holder 12, and includes, for example, a photoelectric sensor 41 and a detection dog 42. The detection dog 42 is installed on the outer periphery of the upper portion of the socket holder 12 so as to be slidable in the axial direction, and is fixed to both ends of the horizontal shaft 33 protruding from the guide hole 34. A slit 43 is formed in a lateral direction on a part of the outer peripheral surface of the detection dog 42. The photoelectric sensor 41 is, for example, a transmission type composed of a pair of light projecting sensor 41a and light receiving sensor 41b, and a pair of the light projecting sensor 41a and light receiving sensor 41b is placed at a fixed position on both sides of the slit 43 of the detection dog. Oppositely arranged with their optical axes aligned. The light projecting sensor 41a and the light receiving sensor 41b are fixed to a support arm 44 extending from the outer periphery of the upper side wall of the socket holder 12, and the attachment positions of both are two types as described in the operation state of FIGS. It is set so that the type of the bolts 1a and 1b can be detected.
[0019]
In the in-situ state shown in FIGS. 1 and 2, the nut runner 10 starts operating so as to tighten the bolt 1 a or 1 b located at a predetermined tightening coordinate, and two types of bolts 1 a are inserted into the hexagonal holes 21 of the socket 20. One of the heads 2a and 2b of 1b is fitted. When the bolt at the tightening coordinate is one type of bolt 1a, the bolt head 2a is fitted into the hexagonal hole 21 of the socket 20 as shown in the left half of FIG. 3 and FIG. The shape detection shaft 31 is pushed up against the spring force of the spring material 32 at the top surface, and the shape detection shaft 31, the horizontal shaft 33 integrated therewith, and the detection dog 42 are relative to the socket 20 and the socket holder 12. Move up. When the bolt at the tightening coordinate is another type of bolt 1b, as shown in the right half of FIGS. 3 and 4, a bolt head 2b having a recess 3 at the center of the top surface of the hexagonal hole 21 of the socket 20 is provided. The shape detection shaft 31 is pushed up against the spring force of the spring material 32 on the bottom surface of the recess 3 that is fitted and is lower than the top surface of the head 2a, and the shape detection shaft 31 and the side thereof are integrated with the shape detection shaft 31. The shaft 33 and the detection dog 42 move upward relative to the socket 20 and the socket holder 12.
[0020]
Thus, the axial displacement of the left half of FIG. 4 and the right half of FIG. 4 of the shape detection shaft 31 whose relative position with respect to the socket 20 is displaced differs by the depth t of the recess 3. This displacement difference t is a displacement difference between the horizontal axis 33 and the detection dog 42 which are displaced up and down integrally with the shape detection shaft 31, and a height difference of the slit 43 of the detection dog 42. Here, for example, when the shape detection shaft 31 is displaced by one type of bolt 1a, the slit 43 is disengaged from the optical axis of the photoelectric sensor 41, and the displacement of the shape detection shaft 31 by the other bolt 1b is the position of the optical axis of the photoelectric sensor 41. The slit 43 is set to move.
[0021]
Then, when the bolt 1a is fitted in the socket 20, the slit 43 is removed upward from the optical axis of the photoelectric sensor 41 as shown in the left half of FIG. 4, and the light from the light projecting sensor 41a is blocked by the detection dog 42. And does not reach the light receiving sensor 41b. When another type of bolt 1b is fitted into the socket 20, the slit 43 is aligned with the optical axis of the photoelectric sensor 41 as shown in the right half of FIG. Is received by the light receiving sensor 41b. The type of the bolt head fitted to the socket 20 is detected based on whether the light receiving sensor 41b receives light or not, and the type of bolt to be tightened at the tightening coordinates is detected.
[0022]
The above bolt type detection is performed immediately before the nut runner 10 starts the bolt tightening operation at an arbitrary or specific tightening coordinate, and the detected bolt type data is output to, for example, the nut runner drive control system. It is used for confirmation operation.
[0023]
Before the nut runner 10 tightens the bolt of the tightening coordinate, it is determined whether or not the bolt type detected by the photoelectric sensor 41 matches the bolt type installed at the preset tightening coordinate. Then, the nut runner 10 is tightened with the bolt fitted to the socket 20 with a tightening torque or a tightening angle corresponding to the bolt type. Also, if it is determined that the bolt type detected by the photoelectric sensor 41 and the bolt type installed at the preset tightening coordinates do not match, this mismatch is confirmed and the bolt tightening operation by the nut runner 10 is interrupted. The control system is activated, and information such as the wrong bolt type at the tightening coordinate is displayed. Such a bolt type confirmation operation is performed at a plurality of tightening coordinates, and a plurality of types of bolt tightening operations at each tightening coordinate are always made accurate to reduce troubles such as bolt breakage due to excessive tightening. .
[0024]
The bolt shape applied in the above embodiment is not limited. For example, the present invention can be applied to the bolts shown in FIGS.
[0025]
The two types of bolts 1c and 1d shown in FIG. 5 are obtained by making the thicknesses of bolt heads 2c and 2d having the same nominal size different by a predetermined value t. The top surfaces of the bolt heads 2c and 2d are flat, and the bolt head shape and the bolt type are detected in the same manner as in the above embodiment based on the thickness difference t.
[0026]
The two types of bolts 1e and 1f shown in FIG. 6 are formed by forming recesses 3e and 3f whose depths are different by a predetermined value t at the center of the book face of the bolt heads 2e and 2f having the same nominal size and thickness. It is. The bolt head shape and bolt type are detected by the difference t between the depths 3e and 3f of the bolt heads 2e and 2f in the same manner as in the above embodiment.
[0027]
The two types of bolts 1g and 1h in FIG. 7 have one top surface of the bolt heads 2g and 2h having the same nominal size and thickness, and the other top surface has a convex portion 4 having a thickness t at the center. . The thickness t of the convex portion 4 is the difference between the substantial thicknesses of the bolt heads 2g and 2h, and the bolt head shape and bolt type are detected in the same manner as in the above embodiment.
[0028]
Moreover, although the said embodiment respond | corresponds to two types of bolts, this invention can respond also to two or more types of bolts. For example, in the bolt 1c in FIG. 5, the bolt 1e in FIG. 6, and the bolt 1g in FIG. 7, the bolt axial thickness (height) at the center of the top surface of the bolt head having the same nominal size is varied in three stages. Even if there are three types of bolts, the present invention can be easily applied.
[0029]
The bolt shape detecting means in the present invention is desirable because a shaft-like member such as a shape detecting shaft is simple in structure and can be easily applied to an existing nut runner, but may be other switches. The bolt type detecting means is also desirable because the photoelectric sensor can be easily applied to an existing nut runner, but other switches may be used.
[0030]
【The invention's effect】
According to the present invention, the bolt type is detected via the bolt shape detecting means mounted on the socket immediately before the bolt head of the tightening coordinates is fitted to the socket of the nut runner and the bolt is tightened. It is possible to confirm whether or not to start bolt tightening by determining whether or not the type of bolt with the attached coordinates is appropriate, and always apply multiple types of bolts to multiple tightening coordinates at the appropriate tightening torque or tightening. A highly reliable nutrunner that can be tightened at an angle can be provided.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an nut runner in an in-situ state showing an embodiment of the present invention. FIG. 2 is an enlarged view of a main part of FIG. 1. FIG. 3 is a longitudinal section of the nut runner of FIG. Fig. 4 is an enlarged view of the main part of Fig. 4. Fig. 5 is a partial front view including partial cross sections of two types of bolts. Fig. 6 Partial front view including partial cross sections of bolts [Fig. 7] Partial front view including partial cross sections of two types of bolts [Explanation of symbols]
1a to 1h Bolt 2a to 2h Bolt head 10 Nut runner 11 Output shaft 12 Socket holder 20 Socket 30 Bolt shape detection means 31 Shape detection shaft 40 Bolt type detection means 41 Photoelectric sensor

Claims (3)

A nut runner that fits a socket provided at the tip to a bolt head to be tightened and tightens a bolt with a flange. The nut runner is fitted into the socket so as to be relatively movable in the socket axial direction. With the gap between the top of the socket and the bolt head, contact the bolt head flange , and the bolt heads of different types with different axial shapes Bolt shape detecting means whose position is displaced, and bolt type detecting means for detecting the bolt type based on the axial shape of the bolt head from the displacement of the relative position of the bolt shape detecting means with respect to the socket immediately before the bolt tightening. Nut runner characterized by   The nut runner according to claim 1, wherein the bolt shape detecting means has a shape detecting shaft whose relative position with respect to the socket is displaced for each of different axial shapes of the bolt heads fitted in the socket.   The nut runner according to claim 1, wherein the bolt type detecting means includes a photoelectric sensor for optically detecting a displacement of a relative position of the bolt shape detecting means with respect to the socket.

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