JPH08201194A - Screw-clamping torque measuring method and its torque measuring unit - Google Patents

Abstract

PURPOSE: To provide a screw clamping torque-measuring method and its measuring unit for efficiently and automatically control clamping torque by using an inexpensive screw clamping torque-measuring unit without changing a production line. CONSTITUTION: A torque measuring unit is provided with a mounting stand 8 fixed to a torque measurement position and an engagement part 4a which is engaged with the tip of the pit of a screw-clamping machine at the center on the upper end face and the lower edge is provided with a torque measurement shaft 1 fixed to the mounting stand 8, a distortion detection sensor 3 for detecting the distortion of the torque measuring shaft 1, a cover part for protecting the torque measurement shaft 1, and a transfer mechanism 7 for taking out the output of the distortion detection sensor 3 to the outside of the cover part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw tightening torque measuring method for a screw tightening device in a screw tightening work line and a torque measuring unit therefor.

[0002]

2. Description of the Related Art A screw tightening device attached to a robot or placed in an assembly process and used for high-mix low-volume production has a setting change of tightening torque in order to efficiently process high-mix low-volume production. It must be easy and can be automated. Furthermore, recently, in order to improve the quality of screw tightening, it is required to guarantee the accuracy of tightening torque.

In the first conventional example of the tightening torque assurance method, the object that has been tightened is extracted and inspected, and the return torque necessary for returning the tightening or the increasing torque necessary for further tightening is measured, and the measured torque is measured. Is compared with the target torque, and when the operator determines that the calibration is necessary, the calibration value is calculated, and the obtained calibration value is taught to the controller of the screw tightening machine.

In the second conventional example, the bit is attached to the tip of the rotating part of the screw tightening machine via the torque detection sensor, the tightening torque is measured every time the screw tightening work is performed, and the obtained measured value is used as the control part. Feedback to control the tightening torque of the screw tightener.

[0005]

However, in the first conventional example, there is a problem that it takes time to measure and calibrate the torque and the efficiency is lowered. Further, there is a problem that skill is required to measure the return torque and the increased torque, and the measurement result varies depending on the operator. Further, since it is the post-measurement, even if there is an abnormal value in the measurement result, there is a problem that it is not possible to determine whether the cause is an abnormality of the screw tightening target or an abnormality of the screw tightening device side.

In the second conventional example, torque measurement and calibration do not require time, are highly efficient, and can be automated.
There is a problem that it is necessary to attach the torque detection sensor to each of the screw tightening devices. Further, since the torque detection sensor is distorted at each measurement, the change over time becomes large, and in the second conventional example in which the measurement is always performed, the reliability of the measured value is impaired.

The present invention solves the above-mentioned problems and uses a screw tightening torque measuring unit which is inexpensive and does not change the production line. The tightening torque can be efficiently and automatically controlled. An object is to provide a measuring method and a torque measuring unit thereof.

[0008]

The screw tightening torque measuring method according to the first invention of the present application has, in order to solve the above-mentioned problems, a meshing portion that meshes with the tip of a bit of a screw tightening machine, and detects strain. A torque measuring shaft equipped with a sensor is attached to a carrier table that is transported to the carrier means of the production line, and the carrier table is positioned by the carrier means at the screw tightening position of the screw tightener of the production line. It is characterized by measuring the tightening torque.

In order to solve the above-mentioned problems, the screw tightening torque measuring method of the second invention of the present application has a meshing portion that meshes with the tip of the bit of the screw tightening machine, and has a strain detecting sensor. The shaft is attached to a carrier that is conveyed to the conveying means of the production line, the conveying table is positioned at the screw tightening position of the screw tightener of the production line by the conveying means, and the final tightening torque of the screw tightener is measured, The feature is that the measurement result is displayed.

In order to solve the above-mentioned problems, the screw tightening torque measuring method according to the third invention of the present application has a meshing portion that meshes with the tip of the bit of the screw tightening machine, and has a strain detecting sensor. The shaft is attached to a carrier that is conveyed to the conveying means of the production line, the conveying table is positioned at the screw tightening position of the screw tightener of the production line by the conveying means, and the final tightening torque of the screw tightener is measured, The measurement result is fed back to the control of the screw tightener.

In order to solve the above-mentioned problems, the screw tightening torque measuring unit of the fourth invention of the present application has a mounting base fixed at the torque measuring position, and a meshing portion which meshes with the tip of the bit of the screw tightening machine. And a torque measuring shaft fixed to the mounting base, and a strain detecting sensor for detecting a strain of the torque measuring shaft.

In order to solve the above-mentioned problems, the screw tightening torque measuring unit of the fifth invention of the present application has a mounting base fixed at the torque measuring position and a meshing portion that meshes with the tip of the bit of the screw tightening machine. Further, it is characterized in that it has a torque measuring shaft fixed to the mounting base, a strain detecting sensor for detecting a strain of the torque measuring shaft, and a measurement result display means.

In order to solve the above-mentioned problems, the screw tightening torque measuring unit of the sixth invention of the present application has a mounting base fixed at the torque measuring position and a meshing portion that meshes with the tip of the bit of the screw tightening machine. Further, it is characterized by comprising a torque measuring shaft fixed to the mounting base, a strain detecting sensor for detecting a strain of the torque measuring shaft, and means for transmitting a measurement result to an external device.

[0014]

The screw tightening torque measuring method of the first invention of the present application and the screw tightening torque measuring unit of the fourth invention of the present application have a meshing portion that meshes with the tip of the bit of the screw tightening machine, and
A torque measuring shaft equipped with a strain detection sensor is attached to a carrier table that is transported to the carrier means of the production line, and the carrier table is positioned by the carrier means at the screw tightening position of the screw tightener of the production line. Since the final tightening torque is measured, the measurement is performed only when torque measurement is necessary, the change in torque detection accuracy with time is small, and the reliability of measurement can be maintained for a long time as compared with the related art.

In the prior art, the tightening torque is measured at the time of screw tightening work or in the product sampling inspection. Therefore, the measurement results include product variations, and the measurement results are used for adjusting the screw tightening machine. Although it may be difficult to make a judgment when using the screw tightener, in the present invention, since the tightening torque of the screw tightener itself can be measured, the judgment in adjusting the screw tightener becomes clear.

Since the torque measuring shaft is fixed to the carrier, the tightening torque of a plurality of screw tighteners can be measured with one torque measuring shaft during the screw tightening process.

The screw tightening torque measuring method of the second invention of the present application and the screw tightening torque measuring unit of the fifth invention of the present application are
In addition to the operation of the first or fourth invention of the present application, since the measurement result is displayed, it is easy for the operator to confirm.

The screw tightening torque measuring method of the third invention of the present application and the screw tightening torque measuring unit of the sixth invention of the present application are
In addition to the operation of the first or fourth invention of the present application, the measurement result is fed back to the control of the screw tightening machine, so that the control can be automated.

[0019]

EXAMPLE A first example of a screw tightening torque measuring method using an example of the screw tightening torque measuring unit of the present invention is shown in FIG.
~ It demonstrates based on FIG.

FIG. 1 is a partial sectional side view of an example of the screw tightening torque measuring unit of the present invention, and FIG. 2 is a perspective view of FIG.

1 to 3, the screw tightening torque measuring unit A has a torque measuring shaft 1 in which a sample screw 4 is screwed into the center of the upper end surface and the lower end is fixed to a mount 8. A strain detecting sensor 3 is provided on the torque measuring shaft 1, and the screw tightening torque is taken out as an output of the strain detecting sensor 3. The mounting table 8 is mounted on the carrier table 13. As shown in FIG. 3, the transfer table 13 is placed on the transfer means 12 of the screw tightening line, transferred together with the transfer table 13a on which the screw tightening target work is placed, and positioned at the screw tightening position. In this case, the head portion 4a of the sample screw 4 is preferably the same type as the head portion of the screw used. Further, in the present embodiment, the torque measuring shaft 1 is vertically fixed to the mounting base 8 with the sample screw 4 on the upper side. Alternatively, it may be attached in an oblique direction.

FIG. 3 is a block diagram showing a screw tightening line using the first embodiment of the screw tightening torque measuring method of the present invention using the screw tightening torque measuring unit A shown in FIGS.

In FIG. 3, the screw tightening torque measuring unit A is fixed to a carrier 13, and the carrier 13 is also equipped with a display means 14. The screw tightening line is
A screw tightening machine 10 for tightening a screw, a screw tightening control section 11 for controlling a screw tightening operation of the screw tightening machine 10, a transfer means 12 used in a production line, and a transfer table 13a on which a screw tightening target work is placed. And a carrier table 13 on which the screw tightening torque measuring unit A and the display means 14 are mounted.

Next, the operation of this embodiment will be described with reference to FIGS.

As shown in FIG. 3, in the screw tightening line,
The workpiece to be screw-fastened is placed on the carrier 13a, and the carrier 12 carries the carrier 13a and positions it at the screw tightening position of each screw tightener 10.
The screw tightening conditions are controlled by the controller 11 to tighten the screw.

In this case, in this embodiment, each screw tightening machine 1
In order to guarantee the accuracy of the final tightening torque of 0, the transport line 13 having the screw tightening torque measurement unit A and the display means 14 is provided on the production line for each predetermined number of the transport tables 13a on which the workpieces to be screwed are placed. Mix in. By doing so, each screw tightening machine 10 performs a work of tightening the sample screw when the carrier 13 on which the screw tightening torque measuring unit A and the display means 14 are mounted is positioned.
Since the final tightening torque generated at that time is displayed on the display means, the operator can accurately confirm the actual final tightening torque of each screw tightening machine 10. In this case, if the head portion 4a of the sample screw 4 is made to have the same shape as the head portion of the screw to be used, the reliability of accuracy guarantee of the final tightening torque is improved.

Even if a large number of screw tightening machines 10 are installed on the screw tightening line, if there is only one carrier 13 on which the screw tightening torque measuring unit A and the display means 14 are mounted, the final screw tightening machine 10 can be installed. The accuracy of tightening torque can be guaranteed.

Since the screw tightening torque measuring unit A of the present invention is used only when it is desired to measure the torque, even if the torque detecting sensor 3 has poor durability,
The reliability of measurement can be maintained for a long time, and the problem of reliability of measured values in the conventional example can be solved. Needless to say, the screw tightening torque measurement unit A of the present invention is not limited to the structure of the embodiment, and its design is free. For example, a cover portion may be attached to the torque measuring shaft 1 and the strain detection sensor 3, and a slip ring or a brush may be used to take out the output of the strain detection sensor 3.

A second embodiment of a screw tightening torque measuring method using an example of the screw tightening torque measuring unit of the present invention will be described with reference to FIGS. 1, 2 and 4.

1 and 2 are similar to those of the first embodiment, the description thereof will be omitted.

FIG. 4 is a block diagram showing a screw tightening line using a second embodiment of the screw tightening torque measuring method of the present invention using the screw tightening torque measuring unit A shown in FIGS.

In FIG. 4, the screw tightening torque measuring unit A is fixed to the carrier 13, and the carrier 13 is also equipped with a transmitting means 15. The screw tightening line is
A screw tightening machine 10 for tightening a screw, a screw tightening control section 11 for controlling a screw tightening operation of the screw tightening machine 10, a transfer means 12 used in a production line, and a transfer table 13a on which a screw tightening target work is placed. And the above torque measuring unit A
And a transmitter 13 on which a transmitter 15 is mounted, and further a receiver 16 for receiving the measurement result transmitted by the transmitter 15 and a calibration value by comparing the received measurement result with a target value. And calibrating means 17 for teaching to the control unit 11.

Next, the operation of this embodiment will be described with reference to FIGS.
It will be described based on.

Until the measurement result of the screw tightening torque measuring unit A is obtained, it is the same as that of the first embodiment, and the description thereof will be omitted.

The output measurement result is transmitted to the outside by the transmitting means 15. The transmitted measurement result is received by the receiving means 1.
It is transferred to the calibration means 17 via 6. Calibration means 17
Calculates a calibration value from the transferred measurement result and the target value, and teaches the control unit 11. After the transfer of the measurement results is completed, the carrier table 13 is moved to the next step by the carrier means 12. As shown in FIG. 4, when there are a plurality of screw tighteners 10, the same processing as above is repeated.

The transmission method may be any of a wired transmission method provided with a contact, an optical communication method in which transmission / reception units are opposed to each other, a wireless transmission method and the like. Therefore, the number and position of the receiving means 16 can be set arbitrarily.

A third embodiment of a screw tightening torque measuring method using an example of the screw tightening torque measuring unit of the present invention will be described with reference to FIGS. 1, 2 and 5.

Since FIGS. 1 and 2 are the same as the first embodiment, the description thereof will be omitted.

FIG. 5 is a block diagram showing a screw tightening line using a third embodiment of the screw tightening torque measuring method of the present invention using the screw tightening torque measuring unit A shown in FIGS.

In FIG. 5, the screw tightening torque measuring unit A is fixed to the carrier 13, and the carrier 13 is equipped with the transmitting means 15 and the storing means 18. The screw tightening line includes a screw tightening machine 10 for tightening a screw, a screw tightening control section 11 for controlling the screw tightening operation of the screw tightening machine 10, a transfer means 12 used in a production line, and a screw tightening target work. The placed carrier table 13a, the screw tightening torque measuring unit A, the transmitting means 15, and the storing means 1
8 is mounted on the carrier table 13, and the receiving means 16 for receiving the measurement result transmitted by the transmitting means 15 and the received measurement result and the target value are compared to calculate a calibration value. , And calibration means 17 for teaching the control unit 11.

Next, the operation of this embodiment will be described with reference to FIGS.
It will be described based on.

Until the measurement result of the screw tightening torque measuring unit A is obtained, it is the same as that of the first embodiment, and the description thereof will be omitted.

The output measurement result is stored in the storage means 18. After the storage of the measurement results is completed, the carrier 13 is moved to the next step by the carrier means 12. After the measurement and storage of the tightening torques of the plurality of screw tighteners 10 are completed,
The transmission unit 15 transmits the measurement result stored in the storage unit 18 to the outside. The transmitted measurement result is received by the receiving means 1.
It is transferred to the calibration means 17 via 6. Calibration means 17
Calculates a calibration value from the transferred measurement result and the target value, and teaches the plurality of control units 11.

The transmission method may be any of a wired transmission method having a contact, an optical communication method in which transmission / reception units are opposed to each other, and a wireless transmission method. Therefore, the number and position of the receiving means 16 can be set arbitrarily.

[0045]

The screw tightening torque measuring method of the first invention of the present application and the screw tightening torque measuring unit of the fourth invention of the present application enable measurement only when torque measurement is necessary, and the change in torque detection accuracy with time is reduced. Compared with the conventional technique, the effect that the reliability of measurement can be maintained for a long time is achieved.

In the prior art, the tightening torque is measured during the screw tightening work or in the product sampling inspection, so that the measurement results include product variations, and the measurement results are used for adjusting the screw tightening machine. Although it may be difficult to make a judgment when using the screw tightener, the present invention has an effect that the tightening torque of the screw tightener itself can be measured, so that the judgment in adjusting the screw tightener becomes clear.

Since the torque measuring shaft is fixed to the carrier, it is possible to measure the tightening torques of a plurality of screw tighteners with one torque measuring shaft during the screw tightening process.

The screw tightening torque measuring method of the second invention of the present application and the screw tightening torque measuring unit of the fifth invention of the present application are
In addition to the operation of the first or fourth invention of the present application, since the measurement result is displayed, there is an effect that the operator can easily confirm.

The screw tightening torque measuring method of the third invention of the present application and the screw tightening torque measuring unit of the sixth invention of the present application are
In addition to the operation of the first or fourth invention of the present application, since the measurement result is fed back to the control of the screw tightening machine, the control can be automated.

[Brief description of drawings]

FIG. 1 is a partial sectional side view of an embodiment of a screw tightening torque measurement unit of the present invention.

FIG. 2 is a perspective view of an embodiment of a screw tightening torque measurement unit of the present invention.

FIG. 3 is a block diagram showing a first embodiment of a screw tightening torque measuring method using the screw tightening torque measuring unit of the present invention.

FIG. 4 is a block diagram showing a second embodiment of a screw tightening torque measuring method using the screw tightening torque measuring unit of the present invention.

FIG. 5 is a block diagram showing a third embodiment of a screw tightening torque measuring method using the screw tightening torque measuring unit of the present invention.

[Explanation of symbols]

 A Screw tightening torque measuring unit 1 Torque measuring shaft 2 Cover part 3 Strain detecting sensor 4 Sample screw 4a Head part (meshing part) 5 Slip ring (transmission mechanism) 6 Brush (transmission mechanism) 7 Lead wire (transmission mechanism) 8 Mounting Base 10 Screw tightener 11 Control unit 12 Conveying means 13 Conveying base 14 Display means 15 Transmitting means 16 Receiving means 17 Calibration means 18 Storage means

Claims (6)

[Claims] A torque measuring shaft having a meshing portion that meshes with a tip of a bit of a screw tightening machine and having a strain detection sensor is attached to a carrier table to be conveyed to a conveying means of a production line. Is determined at the screw tightening position of the screw tightening machine of the production line by the conveying means, and the final tightening torque of the screw tightening machine is measured. 2. A torque measuring shaft having a meshing portion that meshes with a tip of a bit of a screw tightening machine and having a strain detecting sensor is attached to a carrier table to be conveyed to a conveying means of a production line. Is positioned at the screw tightening position of the screw tightening machine of the production line by the conveying means, the final tightening torque of the screw tightening machine is measured, and the measurement result is displayed. 3. A torque measuring shaft having a meshing portion that meshes with the tip of a bit of a screw tightening machine, and a torque measuring shaft equipped with a strain detecting sensor is attached to a carrier table to be conveyed to a conveying means of a production line. Is positioned at the screw tightening position of the screw tightener of the production line by the conveying means, the final tightening torque of the screw tightener is measured, and the measurement result is fed back to the control of the screw tightener. Torque measuring method. 4. A mounting base fixed at a torque measuring position,
Has a meshing part that meshes with the tip of the bit of the screw tightener,
Further, a screw tightening torque measuring unit comprising a torque measuring shaft fixed to the mount and a strain detecting sensor detecting a strain of the torque measuring shaft. 5. A mounting base fixed at a torque measuring position,
Has a meshing part that meshes with the tip of the bit of the screw tightener,
A screw tightening torque measuring unit comprising a torque measuring shaft fixed to the mount, a strain detecting sensor for detecting a strain of the torque measuring shaft, and a measurement result display means. 6. A mounting base fixed at a torque measuring position,
Has a meshing part that meshes with the tip of the bit of the screw tightener,
Further, the screw tightening torque measurement is characterized by having a torque measuring shaft fixed to the mounting base, a strain detecting sensor for detecting a strain of the torque measuring shaft, and means for transmitting a measurement result to an external device. unit.