KR20170129396A - Nut runner system capable of Automatic torque control by wired - wireless communication - Google Patents

Abstract

A nut runner system capable of automatic torque control using wired/wireless communications comprises: a nut runner device unit rotating and fastening a rotary fastener using torque of a servo motor until a rotary fastener reaches a predetermined torque value; a torque sensor unit sensing the torque value; a vibration sensing unit sensing vibration of the nut runner device unit; a torque error monitoring unit monitoring whether the torque value sensed by the torque sensor unit overshoots a set range; an operation control unit controlling operations of the nut runner device unit, the torque sensor unit, the vibration sensing unit, and the torque error monitoring unit, and transmitting the torque value of the nut runner device unit to a communications unit; the communications unit transmitting the torque value of the nut runner device unit through wired and wireless communications; and a monitoring unit storing the torque value transmitted from the communications unit, managing torque data of each of fastened rotary components, and transmitting control data to the operation control unit.

Description

[0001] The present invention relates to a nut runner system capable of automatic torque control using wired / wireless communication,

The present invention relates to a nut runner system, and more particularly, to a nut runner system capable of automatic torque control using wire / wireless communication.

In general, a nut runner refers to a tool that rotates a fastening part such as a bolt or nut by rotating a servo motor.

These nut runners are equipped with a transducer that can sense torque and an encoder that can sense the rotation angle of the servo motor so that the parts can be tightened at a predetermined torque and angle.

Therefore, Nut Runner is installed in automation production lines such as machine parts, electrical and electronic parts assembly line, and automobile assembly line.

There are two ways to tighten parts using nut runner.

There are a torque tightening method in which a fastening component is rotated and fixed by a predetermined torque, and an angle fastening method in which a fastening component is rotated and fixed by a predetermined angle.

Particularly, when a component is fastened by using the torque fastening method, whether or not the fastening is defective is determined by the accuracy of the torque measured by the transducer.

Generally, a transducer is connected between a decelerator and a spindle to measure a torque, convert the torque into an electrical signal, and transmit the signal to the controller.

If the torque of the servo motor is not transmitted to the reducer at this time, the servo motor must continue to rotate until the preset torque is detected by the transducer. Therefore, reliability problems of the nut runner due to overload of the servo motor may occur.

In addition, the overload of the servo motor and the torque measured by the transducer are displayed on the liquid crystal display part of the nut runner, which is a method that the operator can visually confirm at the work site.

Therefore, in a worksite where a plurality of nut runners are installed, the operation state of each nut runner can not be confirmed in real time, so that a failure of fastening due to malfunction of the nut runner may occur.

In an automated production line, when such a fastening failure occurs, a large amount of defective products are produced, resulting in a financial loss.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned technical problems, and it is an object of the present invention to provide an automatic torque control system and a torque control method for controlling a torque value of a nut runner, A possible nut runner system is provided.

According to an embodiment of the present invention, a nut runner device for rotating and fastening a rotary fastener until a rotary fastener reaches a predetermined torque value using a torque of a servo motor; A torque sensor unit for sensing the torque value; A vibration sensing unit for sensing vibration of the nut runner unit; A torque error monitoring unit for monitoring whether the torque value detected by the torque sensor unit exceeds a set range; An operation control unit for controlling operations of the nut runner unit, the torque sensor unit, the vibration sensing unit, and the torque error monitoring unit, and transmitting a torque value of the nut runner unit to a communication unit; The communication unit transmitting the torque value of the nut runner unit through a wire and wireless communication system; And a monitoring unit that stores the torque value transmitted from the communication unit and manages torque data of each of the coupled rotary components and transmits control data to the operation control unit. A nut runner system is provided.

A nut runner system capable of automatic torque control using wired / wireless communication according to an embodiment of the present invention can detect a torque value in real time at a remote place, manage it as torque data, and control a torque value of a nut runner.

Therefore, it is possible to judge whether the fastening failure state, the unworked state and the quality state of the rotary fastening part are determined, and the history thereof can be systematically managed as a database.

1 is a schematic view of a nut runner according to an embodiment of the present invention;
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a nut runner system,
3 is a block diagram of a nut runner system capable of automatic torque control using wired / wireless communication according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, in order to facilitate a person skilled in the art to easily carry out the technical idea of the present invention.

1 is a configuration diagram of a nut runner unit 100 according to an embodiment of the present invention.

The nut runner unit 100 according to the present embodiment includes only a simple structure for clearly explaining the technical idea to be proposed.

Referring to FIG. 1, the nut runner 100 includes an encoder 110, a servo motor 120, a speed reducer 130, a torque sensor 140, a spindle 150, and a socket 160.

The servo motor 120 generates a rotational power, and the encoder 110 senses the rotation angle of the servo motor 120.

The encoder 110 is a kind of position detector and detects a first phase pulse signal A, a second phase pulse signal B and a third phase pulse signal Z representing the rotational direction and the relative position of the servo motor 120 Output. The first phase pulse signal A and the second phase pulse signal B indicate the direction of rotation of the servo motor 120 according to which phase of the signal is fast and the third phase pulse signal Z indicates the rotation direction of the servo motor 120 ) Is pulsed every time it rotates once.

The decelerator 130 is connected to the servo motor 120 to reduce the rotation speed of the servo motor 120 and increase the torque (torque).

One end of the spindle 150 is connected to the speed reducer 130 so that the spindle 150 rotates as the speed reducer 130 rotates.

A torque sensor 140 capable of sensing the torque of the spindle 150 is mounted between the speed reducer 130 and the spindle 150.

The other end of the spindle 150 rotates the rotational force of the spindle 150 so that the socket 160 is directly coupled to the fastening part 170 so that the fastening part 170 can be fastened to the fastened part 180. [ To the fastening part (170).

The operation control unit 190 controls the servo motor 120 so that the rotary fastening member 170 is fastened with a preset torque value.

2 is a configuration diagram of a nut runner system 1 capable of automatic torque control using wired / wireless communication according to an embodiment of the present invention.

The nut runner system capable of automatic torque control using wire / wireless communication according to the present embodiment (1) includes only a simple configuration for clearly explaining the technical idea to be proposed.

Referring to FIG. 2, a nut runner system 1 capable of automatic torque control using wired / wireless communication includes a nut runner 100, a communication unit 200, and a monitoring unit 300.

The detailed configuration and main operation of the nut runner system 1 capable of automatic torque control using the above-described wired / wireless communication will be described below.

The nut runner unit 100 includes an encoder 110, a servo motor 120, a speed reducer 130, a torque sensor 140, a spindle 150, a socket 150, And a controller 160. The components other than the sensors and the operation controller 190 will be collectively referred to as a " nut runner device ".

The nut runner unit rotates until the rotary fastening component 170 reaches a predetermined torque value by using the rotational force of the servo motor 120 and fastens the fastened product 180.

The torque sensor unit 140 senses the torque value. That is, the torque sensor unit 140 is disposed between the speed reducer 130 and the spindle 150 so as to sense the torque of the spindle 150.

That is, after receiving the torque value sensed by the torque sensor unit 140, the operation control unit 190 controls the driving force of the servo motor 120 so that the rotary fastening member 170 is locked at a preset torque value .

The vibration sensing unit 141 senses the vibration of the nut runner unit. The nut runner unit 100 performs a simple repetitive operation and can respond to vibration very sensitively. That is, when a large amount of vibration occurs during the operation of fastening the rotary fastening part 170, the rotary fastening part 170 is not fastened at a set torque value, or the rotary fastening part 170 is separated from the fastened body 180, Failure may occur.

Therefore, the vibration sensing unit 141 senses the vibration in real time, and when the sensed vibration value exceeds the reference vibration value, it can warn the operator using visual and auditory means.

The vibration sensing unit 141 transmits the detected vibration value to the operation control unit 190 and the vibration value is transmitted to the monitoring unit 300 through the communication unit 200. [ Accordingly, the monitoring unit 300 can monitor and manage the vibration state of the nut runner unit 100 in real time.

The torque error monitoring unit 142 monitors whether the torque value detected by the torque sensor unit 140 exceeds the setting range.

The nut runner unit 100 can fasten different types of rotating fasteners 170 with different diameters and different torque values to be fastened to the respective rotating fasteners 170.

Therefore, the torque error monitoring unit 142 stores the reference torque range for each of the rotary fastening components 170. It detects in real time whether the rotary fastening component 170 is fastened beyond the reference torque range, The operator can be warned by using visual and auditory means.

The monitoring value of the torque error monitoring unit 142 is transmitted to the monitoring unit 300 through the communication unit 200. [ Therefore, the monitoring unit 300 can monitor and manage the tightening torque value of the rotary fastening part 170 in real time.

The operation control unit 190 controls operations of the nut runner unit, the torque sensor unit 140, the vibration sensing unit 141, and the torque error monitoring unit 142.

The operation control unit 190 transmits the torque value of the torque sensor unit 140, the vibration value of the vibration sensing unit 141 and the monitoring value of the torque error monitoring unit 142 to the monitoring unit 300 And the monitoring unit 300 manages and manages the transmitted values in the form of a database.

The communication unit 200 exchanges data with the monitoring unit 300 through a wired and wireless communication method.

The communication unit 200 includes a wireless communication module that exchanges data using any one of a Wi-Fi communication method, a Zigbee communication method, and an LTE communication method, and a wireless communication module that exchanges data using an EtherCAT communication method, Module. ≪ / RTI >

The monitoring unit 300 may be defined as a server, a personal computer, and a portable terminal. The portable terminal collectively refers to a portable device such as a mobile phone, smart phone, smart pad, etc., As shown in FIG.

The monitoring unit 300 stores the torque value of the torque sensor unit 140, the vibration value of the vibration sensing unit 141 and the monitoring value of the torque error monitoring unit 142 transmitted from the communication unit 200, do.

In particular, the monitoring unit 300 manages the torque data of the respective fastening fasteners 170 and transmits the control data to the operation control unit 190. The control data includes data for controlling the torque sensor section 140, the vibration sensing section 141 and the torque error monitoring section 142 and the control value of the servo motor 120. [

The monitoring unit 300 monitors the state of the fastening fastener 170 in the fastened state based on the torque value of the torque sensor unit 140, the vibration value of the vibration sensing unit 141 and the monitored value of the torque error monitoring unit 142, Determines a work state and a quality state, and manages the work history in a database.

Therefore, the operator and the manager can monitor the operation status of the nut runner unit 100 by using the monitoring unit 300 such as a smart phone at a remote location, and can quickly respond to the occurrence of a failure in fastening.

Further, the manager can adjust the torque value to which the rotary fastening part 170 is fastened after determining the poor fastening state, unworked state and quality state of the rotary fastening part 170 by using the monitoring part 300 .

3 is a configuration diagram of a nut runner system 2 capable of automatic torque control using wired / wireless communication according to another embodiment of the present invention.

The nut runner system 2 capable of automatic torque control using wired / wireless communication according to the present embodiment includes only a simple configuration for clearly explaining the technical ideas to be proposed.

Referring to FIG. 3, a nut runner system 2 capable of automatic torque control using wire / wireless communication includes a nut runner unit 100, a communication unit 200, and a monitoring unit 300.

The detailed configuration and main operation of the nut runner system 2 capable of automatic torque control using the above-described wired / wireless communication will be described below.

The nut runner unit 100 includes an encoder 110, a servo motor 120, a speed reducer 130, a first torque sensor 140, a spindle 150, And a socket 160, and a second torque sensor 143 is additionally provided. Here, the components excluding the sensors and the operation control unit 190 will be collectively referred to as a " nut runner unit ".

The nut runner unit rotates until the rotary fastening component 170 reaches a predetermined torque value by using the rotational force of the servo motor 120 and fastens the fastened product 180.

The first torque sensor unit 140 senses the torque value. That is, the first torque sensor unit 140 is disposed between the speed reducer 130 and the spindle 150, and is configured to sense the torque of the spindle 150.

That is, after receiving the torque value sensed by the first torque sensor unit 140, the operation control unit 190 basically adjusts the driving force of the servo motor 120 so that the rotational fastening member 170 is set to a preset torque value .

On the other hand, in the nut runner system 2 capable of automatic torque control using wired / wireless communication shown in Fig. 3, a second torque sensor unit 143 is additionally provided.

Hereinafter, the operation of the first torque sensor unit 140 and the second torque sensor unit 143 will be mainly described.

The first torque sensor unit 140 is disposed between the speed reducer 130 and the spindle 150 so as to sense the torque of the spindle 150 as described above.

The second torque sensor unit 143 calculates the drive torque T_1 of the servo motor 120 using the drive current I_DRV of the servo motor 120. [

That is, since the drive torque T_1 of the servo motor 120 is proportional to the drive current I_DRV supplied to the servo motor 120, the second torque sensor unit 143 measures the drive current I_DRV To thereby calculate the drive torque T_1.

The power supply unit supplies power to the driver. The driver supplies a drive control signal (for example, a drive control signal) that is transmitted from the operation control unit 190 DRV_CTRL to the servo motor 120 according to the control of the control unit 120. [ That is, the driver may be composed of a transistor or the like, and the drive control signal DRV_CTRL may be used as a signal for controlling the gate terminal of the transistor.

The torque control of the servo motor 120 is performed by controlling the current flowing into the servo motor 120. The control of the speed, position, and rotation direction of the servo motor also determines the power that is finally supplied to the servo motor 120, .

The servo motor 120 includes an encoder 110. The encoder 110 functions to confirm the number of revolutions of the motor, the direction of rotation of the motor, the number of revolutions, and the initial position of the motor shaft. The encoder 110 may be connected to the rotary shaft of the servo motor 120.

For reference, the method of verifying the current position of the rotor of the servo motor 120 generally counts the current position with reference to the Z phase of the encoder. Therefore, the point at which the Z phase output appears in the encoder is called the initial position of the rotor, and from here, the 360 degree position of the rotor is calculated in relation to the resolution (number of pulses per rotation) of the encoder A and B phases. Therefore, if the resolution of the encoder is high, more accurate data can be obtained in detecting the position of the rotor.

It is possible to determine the forward / reverse rotation because the phase A and phase B of the encoder have a phase difference of 90 degrees with each other. Phase A of phase shift encoder A is 90 degrees ahead of phase B and phase B is 90 degrees phase ahead. When reading the state of phase A at the moment when it changes from Low to High, it is possible to know the forward / reverse rotation by the value at that time.

If the count is cleared or loaded each time a Z-phase pulse is generated, the Z-phase pulse (origin point signal) of the encoder is used to clear the position counter at a constant position every time the rotor makes one revolution. And is loaded. Therefore, when the position of the rotor is determined by the position of the encoder, no cumulative error occurs and a count within the encoder accuracy occurs.

The operation control unit 190 can control the rotation speed and the rotation direction of the servo motor 120 by adjusting the drive current I_DRV supplied to the servo motor 120 using the drive control signal DRV_CTRL.

The operation controller 190 receives the drive current I_DRV supplied to the servo motor 120 and calculates the drive torque T_1 in real time based on the amount of change in the drive current I_DRV over time.

The operation control unit 190 may be configured to directly receive the drive current I_DRV supplied to the servo motor 120 to sense a change amount of the drive current I_DRV. However, in the present embodiment, Receives the sensing current I_1 sensed by the second torque sensor 143 and indirectly senses the amount of change in the driving current I_DRV.

In other words, the second torque sensor unit 143 may be configured as a current transformer (CT). If the driving current I_DRV is directly measured, the measurement time may be restricted due to a too high current value. High current values may cause equipment damage or injury. Therefore, the change amount of the drive current (I_DRV) is stably measured by reducing the current value by using the current transformer for safely measuring the high current.

That is, the current transformer outputs the sensing current I_1 corresponding to the driving current I_DRV in a non-contact manner using the inductance. For reference, the current transformer can be composed of a split core or a solid core.

For reference, the second torque sensor unit 143 may be connected between the power supply unit and the driver to sense the amount of current change and output the sensing current I_1. When the second torque sensor part 143 is connected between the power supply part and the driver, the noise inflow is reduced and the waveform of the sensing current I_1 can be clearly output.

As described above, in another embodiment of the present invention, the torque value at which the rotary fastening component 170 is fastened is set to

Is calculated in consideration of both the torque value T_0 measured by the first torque sensor unit 140 and the drive torque T_1 of the servo motor 120 measured by the second torque sensor unit 143. [

Hereinafter, the torque value T_0 measured by the first torque sensor unit 140 is defined as a first torque value T_0 and the drive torque of the servo motor 120 measured by the second torque sensor unit 143 T_1) is defined as a second torque value T_1.

Ideally, when the first torque value T_0 and the second torque value T_1 are equal to each other, the tightening torque value of the rotary fastening part 170 can be confirmed most accurately.

That is, the second torque value T_1 measured based on the current amount of the servo motor 120 is most ideal when reflected in the first torque value T_0 determined based on the rotational force of the spindle 150, A difference in torque value occurs due to the clearance of the torque sensor.

The reference torque value REF is stored in the operation control unit 190,

When the operation controller 190 tightens the rotary fastening part 170 at a predetermined target torque value T_P,

And determines whether the target torque value T_P has been reached as an average value of the first torque value T_0 and the second torque value T_l.

At this time, the operation control unit 190 sets the reference torque value, the first torque value T_0 and the second torque value T_ 1 to a value before calculating the average value of the first torque value T_0 and the second torque value T_1 Respectively.

When the error range between the reference torque value REF and the first torque value T_0 is within 10-20% and the error range between the reference torque value REF and the second torque value T_1 is within 10-20% The first torque value T_0 and the second torque value T_l are calculated and when the first torque value T_0 and the second torque value T_ 1 exceed one of the error ranges, It is determined whether or not the target torque value T_P has been reached with the remaining torque values excluding the torque value.

The reference torque value REF is defined as an absolute value for comparing the difference between the first torque value T_0 and the second torque value T_1 and basically is set equal to the target torque value T_P .

On the other hand, the operation control unit 190 may use another method for determining whether the rotary fastening member 170 is engaged at the predetermined target torque value T_P.

Basically, since the first torque value T_0 is more accurate than the second torque value T_1,

The operation control unit 190 basically determines the target torque value T_P only by the first torque value T_0 and compares the first torque value T_0 with the second torque value T_1 and then calculates the error And stores it as a correction value. These correction values are updated while being continuously learned.

The operation control unit 190 may be configured to determine the target torque value T_P based on only the second torque value T_1 except for the first torque value T_0, And then determines the target torque value T_P.

The first torque value T_0, the second torque value T_1 and the process of the operation control unit 190 may be transmitted to the monitoring unit 300 through the communication unit 200 and managed.

A nut runner system capable of automatic torque control using wired / wireless communication according to an embodiment of the present invention can detect a torque value in real time at a remote place, manage it as torque data, and control a torque value of a nut runner.

Therefore, it is possible to judge whether the fastening failure state, the unworked state and the quality state of the rotary fastening part are determined, and the history thereof can be systematically managed as a database.

Thus, those skilled in the art will appreciate that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: Nut runner part
110: Encoder
120: Servo motor
130: Reducer
140: first torque sensor
141:
142: Torque error monitoring section
143: second torque sensor unit
150: spindle
160: Socket
170: Rotary fastening part
180: fastener
200:
300: Monitoring section

Claims (3)

A nut runner unit for rotating and fastening the rotary fastener until the rotary fastener reaches a predetermined torque value by using the torque of the servo motor;
A torque sensor unit for sensing the torque value;
A vibration sensing unit for sensing vibration of the nut runner unit;
A torque error monitoring unit for monitoring whether the torque value detected by the torque sensor unit exceeds a set range;
An operation control unit for controlling operations of the nut runner unit, the torque sensor unit, the vibration sensing unit, and the torque error monitoring unit, and transmitting a torque value of the nut runner unit to a communication unit;
The communication unit transmitting the torque value of the nut runner unit through a wire and wireless communication system; And
A monitoring unit that stores the torque value transmitted from the communication unit, manages torque data of each of the coupled rotary components, and transmits control data to the operation control unit;
Which is capable of automatic torque control using wired / wireless communication.
The method according to claim 1,
The monitoring unit,
A failure state, a non-operation state, and a quality state of the rotary fastening part based on the torque value of the torque sensor part, the vibration value of the vibration sensing part, and the monitoring value of the torque error monitoring part, Wherein the automatic torque control can be performed using wired / wireless communication.
The method according to claim 1,
Wherein,
A wireless communication module for exchanging data using any one of a Wi-Fi communication method, a Zigbee communication method, and an LTE communication method; And
And a wired communication module for exchanging data by using an EtherCAT communication method.

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