JP2668302B2 - Method and apparatus for measuring non-contact stress of moving metal strip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving device capable of measuring a propulsive force and a vertical force applied to a metal strip from the linear motor when the metal strip is moved straight by a linear motor. The present invention relates to a method and an apparatus for measuring a non-contact stress of a metal strip.

[0002]

2. Description of the Related Art It is well known that in the process of manufacturing a strip-shaped steel sheet, the tension applied to the steel sheet to be manufactured significantly affects the quality of the steel sheet. Therefore, in the above-mentioned strip-shaped steel sheet manufacturing process, to appropriately control the tension applied to the steel sheet,
This is a very important technology.

Conventionally, in the above-mentioned strip-shaped steel sheet manufacturing process, as a method of controlling the tension applied to the steel sheet, a position of a roll contacting the steel sheet is displaced by an external force, or the steel sheet is wound around a roll, and the roll is rolled. Was controlled by an external force. In such a tension control method, in the case of a high-speed, mass-production line, there is a problem that the length of the steel plate tension control target is required to be several meters or more due to dimensional restrictions of equipment and equipment cost restrictions. .

[0004] In order to solve such a problem, a method of applying a stress to the steel sheet in a non-contact manner by using a linear motor is considered. When the linear motor is used in this way, the dimension of the linear motor becomes the minimum length of the steel plate tension control target length, the texture can be finely controlled, and the tension of any part of the steel plate can be controlled, thereby improving the quality of the steel plate. Will contribute.

As another example of applying such a linear motor to a strip-shaped steel sheet manufacturing process, there is a meandering control of the strip-shaped steel sheet.

Conventionally, a meandering control method for a strip-shaped steel sheet has been performed by displacing the position of a roll in contact with the steel sheet by an external force. However, in the case of such a conventional meandering control method for a strip-shaped steel sheet, since the roll is brought into contact with the high-quality steel sheet, there is a problem that the surface of the steel sheet may be damaged or sometimes its shape may be changed. There was a point.

Therefore, the problem caused by the conventional meandering control can be solved by applying a linear motor and applying a stress to the steel sheet from the linear motor driving unit in a non-contact manner.

However, in the case where a stress is applied to the steel sheet from the linear motor driving unit in a non-contact manner, it is essential to measure the stress applied to the steel sheet in real time online.

By the way, as for a method of measuring the stress applied from the linear motor drive unit (primary winding) to the secondary conductor (moving body side), some offline methods have been proposed and will be briefly described below. .

FIGS. 11 and 12 are views showing an apparatus for detecting a thrust applied to a secondary conductor from a linear motor driving section (primary winding). FIG. 11 is a front view, and FIG.
2 is a plan view.

In the figure, a secondary conductor 112 on an arc and a load cell driving piece 117 are mechanically connected by a pin, a joint, or the like, and a linear motor driving unit 111 sends the secondary conductor 11
The thrust applied to No. 2 is transmitted to the load cell 113 . The load cell 113 is fixed to a support 115 fixed to the base.

FIGS. 13 and 14 are views showing an apparatus for detecting a vertical force applied to a secondary conductor from a linear motor (primary winding). FIG. 13 is a front view, and FIG. It is a top view.

[0013] In Figure, the measuring device may be moved to an applied thrust in the same direction in the secondary conductor 112, and a support base 115 capable of holding one that the distance between the secondary conductors 112 constant A plurality of load cells 116 are arranged between the secondary conductor 112 and the vertical conductor (compression force) applied to the secondary conductor 112 from the linear motor driving unit 111 to the load cell 116. As a result, the vertical force (compression force) applied to the secondary conductor 112 from the linear motor drive unit 111 can be extracted from the load cell 116 .

FIG. 15 is a block diagram showing the principle of the first apparatus for measuring the thrust of a linear pulse motor.

In FIG. 15, the linear pulse motor 21
1 is movable on a base 212 with wheels 213, and is fixed via a spring 214.
In this device, the thrust can be estimated from the amount of expansion or contraction of the spring 214.

FIG. 16 is a block diagram showing the principle of the second apparatus for measuring the thrust of a linear pulse motor.

In FIG. 16, the linear pulse motor 21
Reference numeral 1 denotes a structure in which a wire rope 217 hanging on a heavy object 216 by using a pulley 215 is connected to the base 212 by a wheel 213. In this device, the thrust can be estimated from the heavy object 216.

FIG. 17 is a block diagram showing the principle of the third apparatus for measuring the thrust of a linear pulse motor.

In FIG. 17, the linear pulse motor 21
Reference numeral 1 denotes a unit which is movable on a base 212 with wheels 213, and on which a load 218 is mounted directly. In this device, the linear pulse motor 21
The thrust can be estimated from the mounted load 218 on which the vehicle 1 can travel.

FIG. 18 is a block diagram showing the principle of a fourth apparatus for measuring the thrust of a linear pulse motor.

In FIG. 18, the linear pulse motor 21
1 is a power supply 220, a drive circuit 221, and a pulse generator 2
It is pulse-driven by a motor driving device composed of 22.
The linear pulse motor 211, also being movable I by the wheel 213 on the base 212, and wire rope 223a, a spring 224, wire rope 223b
It is connected to the load cell 225 via. The distortion amount detected by the load cell 225 is displayed on the memory scope 227 after being amplified by the distortion amplifier 226. The thrust of the linear pulse motor 211 can be obtained from the display on the memory scope 227.

However, the measurement of thrust and the like by the above-described measuring devices is to measure the stress applied to the secondary conductor from the linear motor experimentally off-line.

Therefore, in these measurements, in the case of the measuring apparatus shown in FIGS. 11, 12, 13 and 14, the secondary conductor 112 is almost in a stationary state and It is necessary to mechanically connect pins or the like to compress (or pull) the load cell as the detection means.
In the case of the measuring device shown in FIGS. 15 to 18, the linear motor 211 and the detecting means (spring 214, heavy object 216, load 218, or load cell 225) need to be integrally connected and mechanically connected.

Therefore, a method of measuring the stress applied to the steel sheet from the amount of excitation of the linear motor can be considered. However, in this method, the stress applied to the steel sheet even with the same excitation amount, the gap amount between the linear motor and the steel plate, the shape, thickness, material, temperature of the steel plate, and the driving frequency of the linear motor,
Since it is governed by many other factors, it is impossible to estimate the stress to be applied to the steel sheet from the amount of excitation, and it was naturally not practical.

[0025]

As described above, in the case of an apparatus for applying a stress to a steel sheet using a linear motor,
Since it is necessary to accurately control the applied stress, the stress applied to the steel plate must be accurately and reliably detected. However, in the above-mentioned conventional measuring method,
Since the linear motor and the stress detecting means need to be mechanically connected, the detecting means must be moved in synchronization with the steel plate. However, since this steel sheet moves through a large number of rolls, it is extremely difficult to move the detection means in synchronization with the steel sheet, and practical use has been impossible.

[0026]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned inconveniences and installs it on the upper and lower sides of a metal strip.
To provide a non-contact stress measurement method and apparatus for a moving metal strip which enables non-contact and online real-time measurement of stress applied to the strip-shaped metal body continuously driven by a linear motor. With the goal.

[0027]

SUMMARY OF THE INVENTION It is an object of the present invention to support a linear motor drive unit so as to be movable by a fixed distance in a perpendicular direction, and to apply a reaction force of thrust and vertical force applied from the linear motor drive unit to a load cell . This is achieved by allowing them to be transmitted and detected.

That is, according to the first aspect of the present invention, there is provided a non-contact stress measuring method, wherein a supporting structure fixed to a base portion is supported by the supporting structure so as to be movable by a predetermined distance, and both upper and lower sides of a metal strip are provided. And a linear motor drive unit for driving the metal strip in a straight line, the non-contact stress measurement method comprising:
By the magnetic field in the same vertical direction
Ri, based on the detection signal from the detectably each provided with a load cell of each reaction force of a thrust and vertical force applied to the metal strip material, said granted from the linear motor drive unit to the metal strip body thrust and It is characterized by measuring the vertical force.

According to a second aspect of the present invention, there is provided a non-contact stress measuring apparatus, wherein the supporting structure is fixed to a base and is supported by the supporting structure so as to be movable by a predetermined distance. A linear motor drive unit installed and driving the metal strip in a straight line, the linear motor drive unit and the support
A load cell between the structure and the load cell;
Is disposed at a position orthogonal to the moving direction of the metal strip.
The vertical load measuring load cell and the metal strip
A load cell for thrust measurement arranged at a position along the
And the linear motor drive section is configured to
It is characterized by comprising a configuration for applying a magnetic field in the same downward direction .

Furthermore, the non-contact stress measurement apparatus according to the third aspect of the invention, a support structure fixed to the base, by a predetermined distance in the support structure is movably supported, the upper and lower metal strip body A linear motor drive unit installed on both sides to drive the metal strip straight, and the linear motor drive unit and
A load cell between the support structure and the load cell;
At a position perpendicular to the moving direction of the metal strip.
A load cell for normal force measurement,
Load cell for thrust measurement arranged at a position along the movement direction
Consists of a, the above-mentioned linear motor drive unit based on the detection signal and a signal processing circuit for obtaining a thrust and normal force imparted on the metal strip material from each load cell, the linear motor drive unit
Is based on the configuration that applies a magnetic field in the same direction up and down during stress measurement.
It is characterized by becoming .

[0031] In addition, non-contact stress measurement apparatus according to a fourth aspect of the present invention constitutes from said support structure, the support Frames fixed to the base, a support base fixed to the support Frames, the The support shall have all the directions of the reaction force of the thrust.
The linear motor drive is supported via bearings
Be Te is characterized in.

[0032] Non-contact stress measuring device according to the invention of claim 5, wherein the support structure is constituted from a support Frames fixed to the base, a support base fixed to the support Frames, before
The support table has at least a direction of reaction force of the normal force.
By providing a gap corresponding to the mechanical displacement of the load cell,
The near motor drive unit is supported .

[0033]

[0034]

[0035]

According to the invention having the above construction, the metal strip is provided on both upper and lower sides.
Since the linear motor drive unit that location has granted thrust and normal force to the metal strip material, the linear motor allows a constant distance movement drive section in the orthogonal direction, rows of these reaction forces
By transmitting the thrust and the normal force based on the detection signal corresponding to the reaction force from these load cells , the thrust and the normal force can be measured in a non-contact manner with the metal strip.

Further, the linear motor drive unit, since the supported using bearing can be sufficiently reduced amount impaired in the course of the reaction stress to transmit a support mechanism. As a result, the measured values of the thrust and the normal force are sensitivity, reproducibility,
The accuracy is dramatically improved, and a sufficiently practical result is obtained.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments.

FIGS. 1 to 5 show an embodiment of a method and an apparatus for measuring non-contact stress of a moving metal strip according to the present invention. FIG. 1 to FIG. 4 are views showing the mechanism, and FIG.
Is a side view, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, FIG. 3 is a cross-sectional view taken along line BB of FIG. 1, and FIG. FIG. 5 is a block diagram showing a signal processing system.

The non-contact stress measuring device shown in these figures is
The electric circuit unit 1 that measures the stress based on the stress detection signal and generates power for driving the linear motor, and applies stress (thrust and normal force) to the metal strip 2 by the driving power supplied from the electric circuit unit 1. And a mechanical unit 3 capable of detecting stress and supplying a stress detection signal to the electric circuit unit 1.

As shown in FIGS. 1 to 4, the mechanical part 3 is supported by a support structure 31 fixed to a base 30 and movably supported by the support structure 31 at a predetermined distance in a direction perpendicular to the support structure. Linear motor driving units 32U and 32D for driving the band 2 in the Y and Z directions;
Load cells 33a, 33b, 33c, 34 provided between the U and 32D and the support structure 31 so as to detect respective reaction forces of thrust and normal force applied to the metal strip 2 respectively.
a and 34b.

Here, the metal strip 2 is supported by the support structure 3
1, it moves continuously straight from right to left in the drawing (Y direction) . The support structure 31 includes a support frame 35 fixed to the base 30 and a support base 36 fixed to the support frame 35. The support base 36 has an inverted concave shape, and flat attachment pieces 37 are provided at both lower ends. A bearing 39 is provided between the mounting piece 37 of the support base 36 and the upper side of the linear motor mounting plate 38, and a bearing 39 is provided between the lower side of the linear motor mounting plate 38 and the support plate 40. The linear motor mounting plate 38 is mounted on the mounting plate 37 with bolts 41 and nuts 42. This linear motor mounting plate 38
Are guide rollers 43, 4 provided at four corners of the support base 36.
While being regulated by 4, 45, and 46, as shown in FIGS. 3 and 4, the through hole 47 of the linear motor mounting plate 38 is largely drilled with respect to the bolt 41 to form an interval L, so that Y, The load cell 3 is movable in the Y'direction and is adjusted between the linear motor mounting plate 38 and the mounting piece 37 of the support base 36 by adjusting the bolt 41 and the nut 42.
It is possible to move in the Z and Z'directions by providing a gap D that is equivalent to the mechanical displacement amount of 3a, 33b, 33c or is several times that amount.

Further, the load cells 33a, 33b, 3
3c is disposed between the recess of the support base 36 of the support structure 31 and the linear motor mounting plate 38 with a pin 48 interposed therebetween, and is a reaction of the vertical force Z from the linear motor drive units 32U and 32D. The force Z 'is transmitted to the load cells 33a, 33b, 33c via the linear motor mounting plate 38. Further, as shown in FIG. 2, the load cells 34a and 34b are disposed between one end of the linear motor mounting plate 38 to which the linear motor driving units 32U and 32D are fixed, and the support 35p of the support frame 35. ing. Between the other end of the linear motor mounting plate 38 and the support 35q of the support frame 35, a load cell set spring 49,
And a load cell set bolt 50 and a load cell set nut 51. These load cells 33a, 33
b, 33c and the detection signals detected by the load cells 34a, 34b are supplied to the electric circuit unit 1. The electric circuit unit 1 supplies driving power to the linear motor driving units 32U and 32D.

FIG. 5 is a block diagram showing the configuration of the electric circuit section 1 of the present invention.

In FIG. 5, load cells 33a, 33
The detection signal of the reaction force Z ′ of the vertical force Z of the b and 33c and the detection signal of the reaction force Y ′ of the thrust Y of the load cells 34a and 34b are supplied to the signal processing circuit 11 of the electric circuit section 1. The signal processing circuit 11 calculates the thrust Y and the vertical force Z applied to the metal strip 2 in real time based on these detection signals. The signals of the thrust Y and the vertical force Z obtained by the signal processing circuit 11 are supplied to a linear motor drive control circuit 12. This linear motor drive control circuit 12
Then, the thrust Y and the target thrust value setting signal 13 and the vertical force Z and the vertical force target value setting signal 14 from the signal processing circuit 11 are compared with each other, and based on the comparison results, the linear motor driving units 32U and 32D perform the comparison. The drive power is generated so that the stress generated can be controlled.

The operation of the embodiment constructed as described above is shown in FIG.
5 to FIG. 5 and will be described with reference to FIGS.

Here, FIG. 6 shows the load cells 34a, 34
It is a characteristic view which shows the relationship between the measurement data of b, and an ideal curve. FIG. 7 shows characteristics when there is no gap D between the mounting piece 37 and the linear motor mounting plate 38. 8 to 10 show characteristics of the load cells 33a to 33c together with ideal curves.

First, the drive power generated by the linear motor drive control circuit 12 of the electric circuit unit 1 is supplied to the linear motor drive units 32U and 32D. As a result, stress (propulsion force and normal force) is applied to the metal band 2 from the linear motor driving units 32U and 32D, and the metal band 2
In the illustrated example, a rightward to leftward thrust (in this case, acting as a propulsion force) is applied to the metal strip moving from right to left in the Y direction and vertically (Z direction).

At this time, the linear motor mounting plate 38
The reaction force Y 'of the propulsion Y is transmitted to the load cells 34a and 34b between the support 35p and the reaction force Z' of the vertical force Z to the load cells 33a, 33b and 33 between the support 36.
33c.

Here, if a bearing 39 is provided between the mounting piece 37 and the linear motor mounting plate 38, the output Lcy from the load cells 34a and 34b will be changed as shown in FIG. [kg] almost coincides with the ideal straight line Idy. However, if the bearing 39 and the gap L are not provided much between the mounting piece 37 and the linear motor mounting plate 38, as shown in FIG. 7 , the output Lcy from the load cells 34a and 34b becomes less than the applied thrust. [Kg] is apart from the ideal straight line Idy.

The load cells 33a, 33b, 33c
The outputs Lcza, Lczb, Lczc from are shown in FIGS.
As shown in FIGS. 9 and 10 , substantially ideal straight lines Idza and Id with respect to the applied vertical force [kg], respectively.
It matches zb and Idzc.

Then, such ideal measurement data (Lcy, Lcza, Lczb, Lczc) are input to the signal processing circuit 11 of the electric circuit section 1, respectively. The input measurement data (Lcy, Lcza, Lczb, Lczc) is converted into a thrust Y and a vertical force Z in the signal processing circuit 11 according to a predetermined procedure. The thrust Y and the vertical force Z are fed back to the linear motor drive control circuit 12, and are compared with the thrust target value setting signal 13 and the vertical force target value setting signal 14 by the linear motor drive control circuit 12, respectively. The driving power is corrected based on the driving power, and is supplied to the linear motor driving units 32U and 32D again. As a result, even if a linear motor is applied to the strip-shaped steel sheet manufacturing process, the metal strip 2 to be manufactured is provided with an accurate tension equal to the target value, and the meandering control can be performed in a non-contact manner. Will be able to improve the quality of.

In the above embodiment, the position of the load cell set bolt 50 and the load cell set nut 51 is adjusted, and the reaction force Y '(in the direction of the arrow) of the thrust Y is not generated by the load cell set spring 49. Sometimes, the linear motor mounting plate 38 is attached to the load cell 34
a and 34b so as to lightly contact them.

In the above embodiment, the vertical force is applied in the Z direction. However, when the vertical force Z is in the opposite direction, the mechanical displacement is set by, for example, the bolt 41 and the support. This is realized by interposing a disc spring between the plate 40 and the plate 40.

Further, in the above embodiment, the load cell 33
The number of a, 33b, and 33c is three, and the plane position is the center of gravity that divides the output area of the reaction Z 'by １ ／, as shown in FIG. However, the present invention is not limited to this. In addition, in the above embodiment,
The load cells 34a, 34b are mounted on the linear motor mounting plate 38.
Is provided on the right side in the figure, but may be provided on the left side or both sides of the linear motor mounting plate 38 depending on the application. In this case, when the load cells 34a and 34b are provided on both sides, the load cell set spring 49, the load cell set bolt 50 and the nut 51 may be omitted.

[0055]

As described above, according to the non-contact stress measuring method according to the first aspect of the present invention, both the upper and lower sides of the metal strip are provided.
There is an effect that the stress applied to the metal strip from the installed linear motor driving unit can be measured in a non-contact manner.

In the non-contact stress measuring device according to the second aspect of the present invention, the stress applied to the metal band from the linear motor drive units installed on the upper and lower sides of the metal band is taken out of the load cell in a non-contact manner. be able to.

Further, in the non-contact stress measuring device according to the third aspect of the present invention, the stress applied to the metal strip from the linear motor drive units installed on the upper and lower sides of the metal strip is provided in a non-contact manner. Thus, there is an effect that the stress applied to the metal strip can be immediately obtained from the load cell .

According to the third aspect of the present invention, since the stress applied to the metal strip can be obtained, there is an effect that the control accuracy can be improved by using this stress for various controls. .

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a method and an apparatus for measuring non-contact stress of a moving metal strip according to the present invention.

FIG. 2 is a diagram viewed from AA in FIG. 1;

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is an enlarged view of a main part of FIG. 3;

FIG. 5 is a block diagram illustrating a configuration of an electric circuit unit according to the present invention.

FIG. 6 is a characteristic diagram showing a relationship between a thrust obtained by the present invention and an output of a load cell.

FIG. 7 is a characteristic diagram showing a relationship between an output of a load cell and a thrust obtained by the absence of some parts in the present invention.

FIG. 8 is a characteristic diagram showing a relationship between a normal force obtained by the present invention and an output of a load cell.

FIG. 9 is a characteristic diagram showing the relationship between the normal force obtained by the present invention and the output of the load cell.

FIG. 10 is a characteristic diagram showing a relationship between a normal force obtained by the present invention and an output of a load cell.

FIG. 11 is a front view showing a conventional device for measuring thrust of a linear motor.

FIG. 12 is a plan view showing a conventional device for measuring thrust of a linear motor.

FIG. 13 is a front view showing a conventional apparatus for measuring a vertical force of a linear motor.

FIG. 14 is a plan view showing a conventional apparatus for measuring the vertical force of a linear motor.

FIG. 15 is a principle diagram of a first device for obtaining thrust of a conventional linear pulse motor.

FIG. 16 is a principle diagram of a second device for obtaining thrust of a conventional linear pulse motor.

FIG. 17 is a principle diagram of a third device for obtaining thrust of a conventional linear pulse motor.

FIG. 18 is a principle diagram of a fourth device for obtaining thrust of a conventional linear pulse motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric circuit part 2 Metal strip 3 Mechanical part 11 Signal processing circuit 12 Linear motor drive control circuit 13 Target thrust value setting signal 14 Normal force target value setting signal 30 Base 31 Support structure 32U Linear motor drive part 32D Linear motor drive part 33a load cell 33b load cell 33c load cell 34a load cell 34b load cell 35 support frame 36 support base 37 mounting piece 38 linear motor mounting plate 39 bearing 40 support plate 47 through hole 48 pin 49 load cell set spring 50 load cell set bolt 51 load cell set nut L gap D gap

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuichi Sato 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Co., Ltd. Technology Development Division (72) Inventor Mori ▲ Ryuichi Shintomi, Futtsu-shi, Chiba 20- 1 Nippon Steel Corporation Technology Development Division (56) References JP-A-58-1005027 (JP, A) JP-A-52-102779 (JP, A) JP-A-55-99038 (JP, A)

Claims (5)

(57) [Claims] 1. A support structure fixed to a base, and a linear member supported on the support structure so as to be movable by a predetermined distance, installed on both upper and lower sides of a metal band, and driving the metal band in a straight line. A method for measuring non-contact stress in a device comprising a motor drive unit, wherein each linear motor drive installed on both upper and lower sides of the metal strip is provided.
The magnetic field in the vertical same direction through the moving portion, based on the detection signal from the detectably each provided with a load cell of each reaction force of a thrust and vertical force applied to the metal strip material, said metal from said linear motor drive unit A non-contact stress measurement method characterized by measuring a thrust and a normal force applied to a belt. 2. A support structure fixed to a base, and a linear member supported on the support structure so as to be movable by a predetermined distance, installed on both upper and lower sides of a metal band, and driving the metal band in a straight line. The motor drive unit, the linear motor drive unit and the support
A load cell between the holding structure and the load cell;
Is disposed at a position orthogonal to the moving direction of the metal strip.
The vertical load measuring load cell and the metal strip
A load cell for thrust measurement arranged at a position along the
And the linear motor drive section is configured to
A non-contact stress measurement device configured to apply a magnetic field in the same direction below . 3. A support structure fixed to a base, and a linear device movably supported by the support structure for a predetermined distance, installed on the upper and lower sides of a metal band, and driving the metal band in a straight line. The motor drive unit, the linear motor drive unit and the support
A load cell between the holding structure and the load cell;
Is placed at a position orthogonal to the moving direction of the metal strip.
The vertical load measuring load cell and the metal strip
A load cell for thrust measurement arranged at a position along the
From made, the said linear motor drive unit based on the detection signal and a signal processing circuit for obtaining a thrust and normal force imparted on the metal strip material from each load cell, the linear motor drive unit
Is based on the configuration that applies a magnetic field in the same direction up and down during stress measurement.
Non contact stress measuring device comprising. 4. The support structure includes a support frame fixed to a base and a support table fixed to the support frame, and the support table includes a bearing that slides in a reaction force direction of the thrust. The non-contact stress measuring device according to claim 2, wherein the linear motor driving unit is supported by the linear motor driving unit. 5. The support structure includes a support frame fixed to a base and a support table fixed to the support frame. The support table has at least a load cell in a direction of a reaction force of the normal force. 5. The non-contact stress measuring device according to claim 2, wherein the linear motor driving unit is supported with a gap corresponding to a mechanical displacement amount.