JP2005043239A - Micro-displacement control device, and device and method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To constitute an expansion/contraction control device of a supermagnetostrictive element capable of controlling the expansion/contraction quantity and a displacement resulting therefrom with very high accuracy without using an electromagnet basically, and to provide a micro-displacement control device capable of acquiring a target micro-displacement highly accurately by using the expansion/contraction control device. <P>SOLUTION: In the expansion/contraction control device of the supermagnetostrictive element, a bar-shaped supermagnetostrictive element is arranged in a block comprising a non-magnetic substance, and a generation means of a magnetic force only by a permanent magnet is arranged on the fixed end side of the supermagnetostrictive element, and the supermagnetostrictive element is continuously expanded or contracted by controlling continuously the relative position relation between the magnetic force generation means and the supermagnetostrictive element by a moving means of the magnetic force generation means, and the displacement is outputted to the free end side of the supermagnetostrictive element. In this micro-displacement control device, the target micro-displacement is acquired by the displacement outputted to the free end side of the supermagnetostrictive element by using the expansion/contraction control device. Various devices using the micro-displacement control device are also provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a micro displacement control apparatus using a giant magnetostrictive element suitable for use in optical equipment, precision processing machines, laser equipment, measuring instruments, and other equipment that requires minute and precise displacement and feed, and in particular, a Vickers indenter. For example, by a single indentation test of a thin film, the hardness is suitable for obtaining supplementary data on specific physical properties (for example, elastic modulus, creep property, Young's modulus) as well as absolute hardness values. The present invention relates to a micro-displacement control device suitable for measuring the thickness and the like, and an apparatus and method using the same.

  A conventional hardness tester using micro displacement control, for example, generates a load with a coil, transmits the force to a measurement indenter, pushes the indenter into the sample, and precisely measures the displacement at this time with a capacitance displacement meter. Measurement is performed (for example, Patent Document 1). This method is a method in which the load generation portion is performed in an open loop.

  The following are known as measuring devices and actuators using giant magnetostrictive elements. For example, in the giant magnetostrictive actuator disclosed in Patent Document 2, a cylindrical permanent magnet, a giant magnetostrictive rod arranged along its central axis, and the upper end and the lower end of the casing are closed to form a closed magnetic circuit. A pair of upper and lower yokes are provided. In order to apply a magnetic bias to the giant magnetostrictive rod, an electromagnet formed by winding a coil around the giant magnetostrictive rod is disposed in a space surrounded by the permanent magnet and the yoke. A spring for prestressing the giant magnetostrictive rod is disposed between the casing and the yoke.

  According to this giant magnetostrictive actuator, a magnetic bias is applied to the giant magnetostrictive rod through a yoke by a permanent magnet, and a current is supplied to the electromagnet in a state where a prestress is applied by a spring. The giant magnetostrictive rod is expanded and contracted according to the size of the rod, the push rod provided at the tip of the giant magnetostrictive rod is moved, and the displacement is taken out as mechanical power. That is, the displacement accompanying expansion and contraction of the giant magnetostrictive rod is basically controlled by the current of the electromagnet.

In addition to such a giant magnetostrictive actuator, Patent Document 3 discloses a valve opening / closing mechanism using a giant magnetostrictive element and a permanent magnet. When a magnetic force is applied to the giant magnetostrictive element, the valve is closed and no magnetic force is applied. A mode used as an ON-OFF switch such as opening a valve is shown.
JP 2001-124681 A Japanese Patent Laid-Open No. 2002-58269 Utility Model Registration No. 2531546

  However, the hardness tester disclosed in Patent Document 1 uses a capacitance displacement meter for measuring the displacement of the indenter. Capacitive displacement meters are common because they have a very high measurement resolution and enable nano-order measurement. However, since it is a non-contact type, it is very vulnerable to vibration, and it is difficult to ensure a predetermined accuracy unless a considerable cost is applied to the vibration isolation table. Therefore, the entire apparatus is very expensive.

Further, in the giant magnetostrictive actuator as disclosed in Patent Document 2, although the current supplied to the electromagnet can be reduced by the magnetic bias by the permanent magnet, in order to obtain sufficient expansion and contraction of the giant magnetostrictive rod. It still needs a lot of current supply. Therefore, the following problems arise.
(1) When Joule heat is generated, the resistance value of the electromagnet increases, the initial supply current gradually decreases, and the value differs from the initial magnetic force of the electromagnet. As a result, the displacement amount of the giant magnetostrictive rod is changed, and the positioning resolution is lowered accordingly.
(2) The giant magnetostrictive rod is extended due to the influence of Joule heat by the electromagnet, and the control accuracy is also lowered.
(3) Although positively utilizing the cancellation of the magnetic bias by the permanent magnet and the magnetic force by the electromagnet, the permanent magnet is subjected to magnetic stress due to the reverse magnetic force, and the magnetic force of the permanent magnet is changed in a short period of time. May be impossible to control properly.
(4) When the giant magnetostrictive rod is held in an extended state, the current flows and Joule heat is generated in a short time.
In particular, precise control was difficult due to the problems (1) to (4).

  Paying attention to the problems in the prior art as described above, the object of the present invention is basically an expansion / contraction control device for a giant magnetostrictive element capable of controlling the amount of expansion / contraction and the displacement accompanying it without using an electromagnet. It is intended to provide a minute displacement control apparatus that can obtain a target minute displacement with high accuracy using the above.

  Another object of the present invention is to enable various types of measurement and high-accuracy positioning by using such a minute displacement control device. For example, a non-contact displacement meter such as a capacitance displacement meter can be used. Paying attention to the above-mentioned problems of use, basically, without using a non-contact displacement meter, push the indenter with extremely high accuracy using the expansion and contraction control device of the giant magnetostrictive element, and the load accompanying it An object of the present invention is to provide a hardness measuring apparatus and method which can be measured.

  In order to solve the above-mentioned problems, a micro displacement control device according to the present invention has a free end that expands and contracts the giant magnetostrictive element by applying a magnetic force to the giant magnetostrictive element having one end fixed and the other end free. A device for controlling expansion and contraction of a giant magnetostrictive element that outputs end displacement, wherein a rod-like giant magnetostrictive element is arranged in a non-magnetic block, and only a permanent magnet is provided on the fixed end side of the giant magnetostrictive element. By arranging the magnetic force generating means by the above, and continuously controlling the relative positional relationship between the magnetic force generating means and the super magnetostrictive element by the moving means of the magnetic force generating means, the super magnetostrictive element is continuously expanded and contracted. Using a giant magnetostrictive element expansion / contraction control device that outputs the displacement to the free end side of the giant magnetostrictive element, so as to obtain a target minute displacement by the displacement outputted to the free end side of the giant magnetostrictive element. Characterized by Consisting of those. That is, the magnetic force applied to the giant magnetostrictive element is basically controlled by means of magnetic force generation using only permanent magnets, and the giant magnetostrictive element is continuously expanded and contracted so that the displacement is continuously displaced toward the free end side of the giant magnetostrictive element. It is made to output.

  The shape of the permanent magnet used here is not particularly limited, such as a columnar shape, a cylindrical shape, an opposed flat plate shape facing different magnetic poles, an opposed flat plate shape facing the same magnetic poles, a hollow cylindrical shape, a cubic shape, etc. . Since the giant magnetostrictive element expands and contracts regardless of the polarity of the magnetic force, the N pole or S pole of these permanent magnets may be directed to the giant magnetostrictive element, or both may be directed to the giant magnetostrictive element.

  Furthermore, the direction of the magnetic force generated by the magnetic force generation means can be either a direction parallel to the expansion / contraction direction of the giant magnetostrictive element or a direction perpendicular thereto, and an oblique direction is also possible. In short, it is only necessary that the relative positional relationship between the magnetic force generating means and the giant magnetostrictive element can be continuously controlled, and thereby the giant magnetostrictive element can be continuously expanded and contracted.

  The relative positional relationship between the giant magnetostrictive element and the permanent magnet (magnetic force generating means) can be accurately controlled using, for example, a micrometer, a stepping motor, etc., and by controlling the relative positional relationship accurately, By changing the magnetic force applied to the magnetostrictive element, it is possible to accurately expand and contract the desired amount.

  Since the demagnetization of the permanent magnet is said to be about 0.1% per year, a stable magnetic force can be applied to the giant magnetostrictive element for a long time. Further, since the giant magnetostrictive element is expanded and contracted only by the magnetic force of the permanent magnet, there is no Joule heat generation and the predetermined control can be performed accurately.

  Further, in this apparatus, basically, it is only necessary to change the magnetic force applied to the giant magnetostrictive element by one permanent magnet, so that no magnetic stress due to the reverse magnetic force is generated, and demagnetization of the permanent magnet can be suppressed. .

  In this device, when the giant magnetostrictive element is held in an extended state, it is extended only by the magnetic force of the permanent magnet, so that it is stable and reliable without causing problems such as the generation of Joule heat. In addition, it is possible to accurately and accurately maintain the predetermined state.

  In addition, in this device, since the magnetostrictive element is included in the block, it is possible to suppress the influence due to external temperature change, etc., especially by using a non-magnetic material with low thermal conductivity in the block, It is possible to more reliably avoid the influence due to external temperature changes and the like.

  The magnetic force applied to the giant magnetostrictive element is determined by the relative positional relationship between the giant magnetostrictive element and the permanent magnet. At this time, the change in the magnetic force applied to the giant magnetostrictive element is very small with respect to the change in the relative positional relationship. By changing the relative positional relationship, the setting of the magnetic force can be controlled very finely. As a result, the positioning resolution of the apparatus (displacement output resolution on the free end side of the giant magnetostrictive element) can be made extremely high.

  Further, since a magnetic force is given by a permanent magnet with extremely little demagnetization, and the magnetic force acting on the super magnetostrictive element is controlled only by changing the relative positional relationship by the moving means, very high reproducibility can be obtained. Therefore, for example, if the feed amount from the reference point of the permanent magnet is controlled, positioning by an open loop is also possible.

  In such a micro displacement control device according to the present invention, it is preferable to arrange the magnetic force generating means, particularly the permanent magnet, on the axis of the giant magnetostrictive element. It is possible to change the applied magnetic force. It is only necessary that the magnetic force applied to the giant magnetostrictive element can be continuously changed.

  Further, the moving means can be constituted by means for moving the magnetic force generating means in a direction parallel to the expansion / contraction direction of the giant magnetostrictive element, or can be constituted by means for moving in a direction perpendicular to the expansion / contraction direction of the giant magnetostrictive element. You can also. The moving means can be configured as a means for simply moving the magnetic force generating means in a straight line, or can be configured as a means for rotating the magnetic force generating means. In the latter case, for example, a permanent magnet is provided on the rotating plate, and the rotating plate is rotationally controlled by a means capable of controlling the rotation angle such as a stepping motor, so that the relative positional relationship between the magnetic force generating means and the giant magnetostrictive element is accurately determined. It becomes possible to control well. That is, the expansion / contraction of the giant magnetostrictive element can be controlled only by the rotation angle. Moreover, the expansion / contraction speed of the giant magnetostrictive element can be increased by rotating the rotating plate at a high speed.

  On the free end side of the giant magnetostrictive element, it is preferable to provide a push rod made of a magnetic material that is displaced as the giant magnetostrictive element expands and contracts. Since the magnetic permeability of the giant magnetostrictive element is low, the amount of magnetization is high in the vicinity of the permanent magnet on the fixed end side, but the amount of magnetization decreases toward the free end side. Therefore, by providing a push rod made of a magnetic material so as to come into contact with the giant magnetostrictive element on the free end side, and further by arranging the component arrangement from the magnetic force generating means from the one with the lower magnetic permeability to the higher one, Improvements can be made.

  It is also possible to adopt a form in which the push rod side and the magnetic force generating means side are connected by a yoke made of a magnetic material and a magnetic closed circuit is formed between them. As a result, the magnetic characteristics can be further improved and the leakage magnetism can be reduced.

  Moreover, it is preferable that at least one slide guide connected to the push rod and guiding the push rod in the expansion / contraction direction of the giant magnetostrictive element is provided in the block. For example, three slide guides can be arranged in the circumferential direction around the giant magnetostrictive element. With such a structure, it is possible to eliminate shakiness other than the moving direction of the movable part and to improve output efficiency.

  Further, it is preferable that a means for applying prestress to the giant magnetostrictive element from the free end side of the giant magnetostrictive element is provided. For example, prestress can be applied by biasing means such as a spring through the push rod or its mounting member. If such an urging means is provided, it becomes possible to press the end of the push rod on the free end side against the giant magnetostrictive element. The expansion / contraction characteristics are improved and the play in the feed direction is eliminated, thereby enabling more precise control.

  Further, the block is preferably provided with a lid made of a non-magnetic material that is connected to a fixed end of the giant magnetostrictive element and is interposed between the fixed end and the magnetic force generating means. For example, by interposing a lid having a thickness of about 1 mm, the magnetic force from the magnetic force generating means can be applied to the fixed end side of the giant magnetostrictive element in a desired state of a predetermined relative positional relationship, and nonmagnetic By using a lid made of a body, loss of magnetic force from the magnetic force generating means can be suppressed.

  Further, as described above, this block is preferably made of a non-magnetic material having low thermal conductivity. The giant magnetostrictive element is included in the block, and is less affected by thermal expansion due to external temperature change. However, when the external temperature environment is severe, the use of the low thermal conductivity block can improve the temperature change resistance characteristic.

  The block can be provided with heating means, cooling means, or both. By providing such temperature control means, for example, when the external temperature environment is extremely low compared to normal temperature, the block can be warmed by a heater or the like, and the super magnetostrictive element can be brought to normal temperature. Further, when the external temperature environment is extremely higher than the normal temperature, it is possible to cool the block with cooling water or the like to bring the giant magnetostrictive element to the normal temperature state. This enables stable control under desirable conditions.

  In addition, a magnetic force measuring device, for example, a Hall element can be provided on the anti-super magnetostrictive element side of the push rod made of a magnetic material on the free end side of the super magnetostrictive element. Since the push rod is also magnetized in proportion to the magnetization amount of the permanent magnet of the giant magnetostrictive element, the magnetization amount of the giant magnetostrictive element can be monitored by the Hall element. The giant magnetostrictive element has hysteresis, but this is due to residual magnetization. If the amount of magnetization of the giant magnetostrictive element can be monitored, the expansion and contraction can be precisely controlled without considering the hysteresis. That is, the amount of magnetization of the giant magnetostrictive element is directly proportional to the amount of expansion / contraction.

  The micro displacement control device provided with the expansion / contraction control device for the giant magnetostrictive element according to the present invention can be applied to various devices that require minute and precise feed and output. By using it, an ultra-micro hardness measuring device can be configured. That is, the measurement device for hardness or the like according to the present invention is configured to transfer the displacement output to the free end side of the giant magnetostrictive element by the expansion / contraction control device of the giant magnetostrictive element in the minute displacement control apparatus as described above to the object to be measured. And a load measuring device is used to measure the load corresponding to the indentation amount to obtain the indentation amount-load characteristic and hardness value of the object to be measured.

  For example, as shown in the drawings described later, in the measurement with this ultra-small hardness measuring apparatus, a portal frame and a base board are connected, and an electronic balance, for example, is placed on the base board. Furthermore, a means capable of coarse movement is placed on the electronic balance. In this device, the output portion is fixed downward on the portal top plate. For example, a Vickers diamond indenter is attached to the output part of this apparatus, and the measurement sample is attached to a movable coarsely adjusted part. The giant magnetostrictive element is expanded and contracted at the shortest position of the expansion and contraction stroke of this apparatus. Next, it is moved and fixed until the indenter comes into contact with the measurement material by the fixable coarse adjustment moving unit. The contact confirmation at this time is performed by checking the value of an electronic balance or the like. Next, a predetermined amount of the indenter is accurately pushed by this apparatus. Read the load at that time with an electronic balance. Further, a predetermined amount is pushed in addition to the pushing amount. Read the load at this time with an electronic balance. This is repeated until the final pushing amount. Further, after reaching the final push-in amount, the push-in is reduced by a predetermined amount, and the load at that time is measured. Further, the load is measured by sequentially subtracting the decrease amount. This is performed up to the starting point of indenter pushing. As a result, a graph of the “minute push amount—load” characteristic can be created, a continuous characteristic curve can be obtained, and the hardness value of each measurement point can be obtained. Since this characteristic curve varies depending on the material, it is possible to compare and evaluate physical properties.

  In such a measuring apparatus, it is desirable to combine with a load measuring apparatus capable of measuring a load without any displacement. For this purpose, a load measuring device such as an electronic balance or a piezoelectric element is suitable. Since the push-in amount is determined by an open loop, if the load measurement is accompanied by a displacement, a separate correction work is required.

  Since the above-mentioned expansion and contraction control device for the giant magnetostrictive element can be pushed in on the nano order, it can be used in combination with a micro load measuring device such as an electronic balance to measure the hardness of a thin film having a thickness of several microns. Moreover, by obtaining a continuous curve of the “push-in amount-load” characteristic, it is possible to analyze not only the hardness but also mechanical properties such as elastic modulus and Young's modulus of a thin film. Furthermore, it is possible to automate the pushing-in of the device and the load measurement, and to continuously measure the pushing amount and the load at the same time. Thereby, more detailed measurement is possible.

  Since the micro displacement control device used in this indenter pushing unit uses expansion and contraction as a material of the giant magnetostrictive element, it is not affected by vibration at all. Thereby, even if the vibration isolator of this ultra micro hardness measuring apparatus is simple, there is no problem. Therefore, it becomes possible to provide a highly accurate device at a low cost as the whole measuring apparatus.

  Further, the micro displacement control device using the super magnetostrictive element expansion / contraction control device according to the present invention as described above can be applied to various devices that require minute and precise feeding and output. By using it, a displacement sensor calibration device can be configured. That is, the displacement sensor calibration apparatus according to the present invention includes the displacement output to the free end side of the giant magnetostrictive element by the expansion and contraction control device of the giant magnetostrictive element in the minute displacement control apparatus as described above, and the output of the target displacement sensor. By contrasting with the above, the output of the target displacement sensor is calibrated. In many cases, the displacement sensor inputs and calibrates any two or three points within the measured displacement range.

  For example, even in the case of a high-precision displacement sensor having nano-order resolution, the zero point / span adjustment of the measurement output (inclination of the output straight line) is performed by changing the thickness of the block gauge. However, with such a high-precision displacement sensor, the accuracy of calibration is poor in a block gauge with sub-micron order variations. Therefore, for example, in the case of a laser displacement sensor, a laser is irradiated to the output portion of the minute displacement control device according to the present invention. Then, the output portion is accurately moved to an arbitrary point using this minute displacement control device. The displacement point data is recorded in the sensor data processing device. By repeating this, it is possible to accurately calibrate the high-precision displacement sensor. It is also possible to install a sensor (in the same direction as the output direction) at the output portion of the minute displacement control device. With this configuration, it is possible to calibrate using an actual object to be measured. If the sensor and the output portion of this apparatus are aligned in advance, it is possible to calibrate more quickly and accurately. A sensor here is a displacement sensor, an absolute length sensor, a strain gauge, etc., and does not ask | require contact and non-contact.

  Further, the micro displacement control device using the super magnetostrictive element expansion / contraction control device according to the present invention as described above can be applied to various devices that require minute and precise feeding and output. By using it, a positioning stage can be configured. That is, in the positioning stage according to the present invention, the stage is positioned by the displacement output to the free end side of the super magnetostrictive element by the super magnetostrictive element expansion / contraction control apparatus in the micro displacement control apparatus as described above. It consists of what is characterized by this. More specifically, for example, an output portion of the minute displacement control device is connected to a slide guide that can slide precisely in only one direction. At this time, if a device in which the Hall element or the like is installed is used, the reciprocating positioning operation can be performed accurately without being affected by hysteresis. Furthermore, the X / Y stage can be configured by superimposing the one-direction stage by shifting by 90 °. Of course, the vertical stage can be further combined into an X, Y, and Z stage, and the combination of positioning directions can be set arbitrarily.

  Similarly, in the method according to the present invention, it is possible to perform measurement and positioning at various places using the micro displacement control device provided with the expansion / contraction control device for the giant magnetostrictive element according to the present invention.

  That is, the measurement method of hardness or the like according to the present invention uses the minute displacement control device as described above, and is measured by the displacement output to the free end side of the giant magnetostrictive element by the expansion and contraction control device of the giant magnetostrictive element. It consists of a method characterized by controlling the amount of indentation into an object, measuring the load corresponding to the amount of indentation using a load measuring device, and obtaining the amount of indentation-load characteristics and hardness value of the object to be measured. .

  Further, the displacement sensor calibration method according to the present invention uses the minute displacement control device as described above, the displacement output to the free end side of the giant magnetostrictive element by the expansion and contraction control device of the giant magnetostrictive element, and the target displacement. The method comprises calibrating the output of the target displacement sensor by contrasting with the output of the sensor.

  Furthermore, the positioning stage control method according to the present invention uses the above-described minute displacement control device, and the displacement output to the free end side of the giant magnetostrictive element by the expansion and contraction control device of the giant magnetostrictive element causes the stage to move. It consists of the method characterized by performing positioning.

  According to the minute displacement control device according to the present invention as described above, the expansion / contraction amount of the giant magnetostrictive element can be maximized with only one permanent magnet, and the expansion / contraction amount is controlled by controlling the relative positional relationship. It becomes possible to control with extremely high precision down to the nano order. In addition, the target predetermined expansion / contraction amount can be reliably reproduced any number of times, and the holding force is excellent. Furthermore, since the number of parts is small with a simple device configuration, it can be manufactured at low cost.

  Further, according to various measuring devices, calibration devices, positioning devices and methods using such a micro displacement control device according to the present invention, desired hardness measurement, sensor calibration, positioning, etc. can be performed with extremely high accuracy and It can be performed easily and with an inexpensive apparatus.

Preferred embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 shows a micro displacement control device provided with an expansion / contraction control device for a giant magnetostrictive element according to one embodiment of the present invention, and FIGS. 2 and 3 respectively show the micro displacement control device according to another embodiment. ing. The expansion / contraction control device for the giant magnetostrictive element in the micro displacement control device according to the present invention shown in these figures is based on the change in the continuous relative positional relationship between the giant magnetostrictive element having one end fixed and the other end being a free end and the permanent magnet. The giant magnetostrictive element is expanded and contracted by a change in magnetic force, and the displacement is output to the free end. In the figure, a rod-shaped giant magnetostrictive element 2 and a micrometer 3a / stepping motor unit 3b (3 in FIG. 3 is a micrometer or a stepping motor unit) arranged coaxially or orthogonally in a block 1 made of a non-magnetic material. ) Or a circular permanent magnet 4 provided at the tip thereof is moved by a moving means comprising a circular cam 17 and the relative positional relationship with the giant magnetostrictive element 2 is controlled. The micrometer 3a or the stepping motor unit 3b is held by a shaft holder 14 made of a magnetic material, and the base 5 includes the moving means side and the block 1 side in which the giant magnetostrictive element 2 is contained via the shaft holder 14. Are connected by The shaft portion of the micrometer 3a or the stepping motor unit 3b is made of a magnetic material, and can form a magnetic closed circuit described later.

  As the giant magnetostrictive element 2, in this embodiment, a cylindrical “ETREMATERFENOL-D” manufactured by Etorima is used, and as the permanent magnet 4, a neodymium magnet having a strong magnetic force among rare earth magnets is used. .

  The block 1 made of a non-magnetic material such as stainless steel or aluminum alloy has three holes on the same circumference, and further has a through hole for inserting the giant magnetostrictive element 2 at the center of the three holes. ing. A flange-like lid body 6 made of a nonmagnetic material such as stainless steel or aluminum alloy is screwed to one of the center holes. The fixed end of the giant magnetostrictive element 2 is formed by receiving the giant magnetostrictive element 2 with the flange-like lid 6 and the lid 6 is made of a non-magnetic substance, thereby minimizing the loss of magnetic force. The magnetic force of the permanent magnet 4 can be applied to the giant magnetostrictive element 2.

  The movable part on the free end side is constituted by a shaft 7 made of three nonmagnetic materials and a magnetic plate 9 that connects a push rod 8 connected to the free end side of the giant magnetostrictive element 2. The end portion of the push rod 8 is rounded to make the contact with the giant magnetostrictive element 2 uniform. The end portions of the three shafts 7 are threaded and fixed to the plate 9 with screws or the like.

  In the apparatus shown in FIG. 1, the micrometer 3a is installed in the shaft holder 14, and the permanent magnet 4 is fixed to the tip by a magnetic force. This makes it possible to move the position of the permanent magnet 4 on the order of microns. In the apparatus shown in FIG. 2, the stepping motor unit 3b is installed in the shaft holder 14, and the permanent magnet 4 is fixed to the surface of the rotary plate 12 at the tip by a magnetic force. Thereby, the rotational position of the permanent magnet 4 can be accurately controlled by the rotation angle control by the stepping motor unit 3b. In the apparatus shown in FIG. 3, the stepping motor unit 3 is installed in the shaft holder 14, and the permanent magnet 4 is connected via the cam bearing 13 engaged with the circular cam 17 by the rotation angle control by the circular cam 17 connected thereto. Can be accurately controlled on the slide guide 16. For example, by adopting a shape in which hysteresis is corrected, highly accurate control can be easily performed without considering hysteresis. Furthermore, for example, when it is desired to obtain a sine output continuously, the cam shape can be changed so that the output of the apparatus finally becomes a sine output, and the stepping motor unit 3 is continuously rotated. Even when a circular cam in which the operation of the permanent magnet is a proportional straight line is used, an arbitrary waveform can be obtained by controlling the rotation speed of the stepping motor unit 3.

  By combining the block 1 and the movable part on the free end side, it is possible to obtain an output that follows the expansion and contraction of the giant magnetostrictive element 2 on the free end side. At this time, the shaft 7 is inserted into each of the three holes on the same circumference of the block 1 together with the slide guide 15 to eliminate rattling other than the feeding direction of the movable part, and further, as a biasing means at the shaft end. Prestress is applied to the giant magnetostrictive element 2 by arranging the spring 10. At this time, the end portion of the push rod 8 which is the free end side is pressed against the giant magnetostrictive element 2, the expansion and contraction characteristics of the giant magnetostrictive element 2 are improved, and the play in the feed direction is also eliminated. Precise control is possible.

  A non-magnetic plate is used as a base 5, and a block 1 and a shaft holder 14 are installed on the base 5 by screwing. For example, in the apparatus shown in FIG. 1, the super magnetostrictive element 2 and the permanent magnet 4 are coaxially connected to the super magnetostrictive element 2. Configure the relative positional relationship. This makes it possible to continuously control the relative positional relationship between the giant magnetostrictive element 2 and the permanent magnet 4 fixed to the tip of the micrometer 3 on the order of microns.

  Further, the magnetic force of the permanent magnet 4 can be directly applied to the magnetic giant magnetostrictive element 2 because the block 1 and the base 5 are non-magnetic, so that the output in the continuous expansion / contraction control of the giant magnetostrictive element 2 is increased. ing. Further, since the magnetic permeability of the giant magnetostrictive element 2 is low, the amount of magnetization is high in the vicinity of the permanent magnet 4 on the fixed end side, but the amount of magnetization decreases toward the free end side. Therefore, a magnetic material is used for the push rod 8 that is in contact with the super magnetostrictive element 2 on the free end side, and the component arrangement from the magnetic force generating means is arranged from the one having the lower magnetic permeability to the higher one (described later). 8) The amount of magnetization can be improved.

  Actually, when a displacement amount of the non-magnetic push rod and the magnetic push rod 8 was compared by using a neodymium permanent magnet 4 of φ12 mm × 10 mm in length, as shown in FIG. In the case of the body, the thickness was 12 μm, and in the case of the magnetic body, it was 17 μm, which was significantly increased. Alternatively, a magnetic closed circuit may be configured by connecting a magnetic material push rod 8 to a yoke 11 (FIGS. 1 and 2) made of a magnetic material. In this case, the amount of expansion and contraction can be further increased as shown in FIG. Further, when iron, which is a magnetic material, was used for the lid 6, the amount of expansion / contraction of the giant magnetostrictive element could be extremely reduced. When iron, which is a magnetic material, was used for the lid 6, the amount of expansion / contraction of the giant magnetostrictive element was extremely reduced to 1 μm or less. From these facts, it can be seen that it is optimal to arrange the component arrangement from the magnetic force generating means from the one with the lower magnetic permeability to the higher one.

  Next, under the condition of the magnetic material push rod and the condition of opening the magnetic circuit (magnetic circuit open), a neodymium permanent magnet 4 of φ14 mm × length 10 mm is fixed to the tip of the micrometer 3a. When the relative positional relationship with the giant magnetostrictive element 2 is changed from a reading value of 25.000 mm to 0 mm, as shown in FIG. 5, a displacement of about 19 μm occurs, and 0.01 μm is set by the operation of the used micrometer 3a. It was possible to control. Further, when the reading of the micrometer 3a was fixed at an arbitrary position between 25.000 mm and 0 mm, the output of the apparatus was fixed and no change was observed.

  FIG. 5 also shows the results of using various types of neodymium permanent magnets with different dimensions and the results of using ferrite permanent magnets of φ12 mm × length 4 mm. As a result, it can be understood that far superior expansion and contraction and displacement characteristics can be obtained by using a neodymium permanent magnet compared to a ferrite permanent magnet.

  FIG. 6 shows an example of the amount of expansion / contraction of the giant magnetostrictive element 2 when the neodymium permanent magnet is moved in the direction perpendicular to the direction of expansion / contraction of the giant magnetostrictive element 2. In this case, the giant magnetostrictive element 2 contracts as the permanent magnet approaches. Such a movement in the vertical direction can be achieved by a linear movement, but can also be achieved in a pseudo manner by a movement of a rotation system as shown in FIG. It can be seen that a smaller displacement can be controlled as shown in FIG. Therefore, it is suitable for obtaining a smaller output displacement.

  In the present invention, the amount of expansion / contraction of the giant magnetostrictive element 2 accompanying the movement of the permanent magnet is more or less, and has hysteresis between the extension direction and the contraction direction. For example, it has hysteresis as shown in FIG. However, even if there is hysteresis in this way, there is no problem in accuracy during measurement and output as long as the hysteresis characteristics are known in advance.

  Furthermore, when a magnetic force measuring device such as a Hall element is installed on the anti-super magnetostrictive element side of the push rod 8, it is possible to grasp the amount of expansion / contraction at that time simply by reading how many gauss the magnetization amount of the push rod 8 is. This is possible and there is no need to consider hysteresis.

  In addition, as illustrated in FIG. 8, the component arrangement from the push rod made of a magnetic material to the magnetic force generation means (permanent magnet) is in order from the magnetic force generation means side to the higher (relative) magnetic permeability. As a result, the amount of magnetization can be improved.

  FIG. 9 shows an ultra micro hardness measuring machine as a hardness measuring apparatus according to an embodiment of the present invention. In the ultra micro hardness measuring machine shown in FIG. 9, as shown in FIG. The base frame 28 provided on the gate frame 31 and the anti-vibration rubber 29 is connected to an electronic balance 27 (for example, PG2002-S manufactured by METTLER TOLEDO). Yes. Further, a Z-axis stage 26 that can move coarsely is placed on the electronic balance 27. The minute displacement control device 21 including the permanent magnet 22, the micrometer 23, and the device fixing base 24 is fixed to the upper surface plate of the portal frame 31 with the output portion facing downward. A Vickers diamond indenter 30 is attached to the output portion of the apparatus 21, and the measurement sample 25 is attached to the Z-axis stage 26. The giant magnetostrictive element is expanded and contracted at the shortest position of the expansion / contraction stroke of the device 21. Next, the fixed Z-axis stage 26 is moved and fixed until the indenter 30 contacts the measurement sample. The contact confirmation at this time is performed by looking at the value of the electronic balance 27. Next, the device 21 accurately pushes the indenter 30 by a predetermined amount. The load at that time is read by the electronic balance 27. Further, a predetermined amount is pushed in addition to the pushing amount. The load at this time is read by the electronic balance 27. This is repeated until the final pushing amount. Further, after reaching the final push-in amount, the push-in is reduced by a predetermined amount, and the load at that time is measured. Further, the load measurement is sequentially performed by subtracting the decrease amount. This is repeated until the indenter pushing start point. Thus, a graph of “push amount—load” characteristics can be created as shown in FIG. 10, for example, and can be obtained as a continuous characteristic curve, and the hardness value of each measurement point can be obtained. This curve differs depending on the material as shown in FIG.

  In this measuring machine, it is desirable to combine with a load measuring device capable of measuring a load without accompanying displacement. A load measuring device such as an electronic balance or a piezoelectric element is suitable. Since the push-in amount is determined by an open loop, if the load measurement is accompanied by displacement, a separate correction work is required.

  In addition, regarding the elastic deformation due to the load applied to the giant magnetostrictive element and the system, no change was observed when the expansion and contraction characteristics were compared with a high-precision length measuring machine with no load and a load of 100 g.

  Since the expansion and contraction control device for the giant magnetostrictive element can be pushed in on the nano order, it can be used in combination with a micro load measuring device such as an electronic balance to measure the hardness of a thin film having a thickness of several microns. Moreover, by obtaining a continuous curve of the “push-in amount-load” characteristic, it is possible to analyze not only the hardness but also mechanical properties such as elastic modulus and Young's modulus of a thin film.

In FIG. 10, the characteristic curve that passes through the zero point of the indenter indentation and the load shows the characteristics at the time of indentation, and the other characteristic curve shows the characteristics at the time of indentation decrease (return direction). There is. The following can be understood from the measurement result shown in FIG.
-There is a difference in the maximum load depending on the substance even at the same indentation depth.
-There is hysteresis in the push-in direction and return direction.
・ The width of hysteresis varies depending on the substance.
-A large hysteresis means that the amount of plastic deformation is large and the amount of elastic deformation is small.
・ Ceramic is hard to plastically deform and is hard.
-Copper has much plastic deformation and is softer than ceramic.
・ If you look at this curve, you can understand the characteristics of the substance at a glance.
・ Evaluation can be made separately for elastic deformation and plastic deformation.
-If the elasticity and plasticity cannot be evaluated separately, rubber will be a very hard substance, for example, in hardness measurement by Vickers.
・ Thin film can be evaluated by reducing the push-in amount.
・ The hardness value can be obtained at each measurement point.

  Further, it is possible to automate the push-in of the minute displacement control device and the load measurement, and simultaneously perform continuous measurement. Thereby, more detailed measurement is possible.

  The expansion / contraction control device for the giant magnetostrictive element used in this indenter pushing unit uses the extension / contraction as a material of the giant magnetostrictive element, and is not affected by vibration at all. Thereby, even if the vibration isolator of this ultra-micro hardness measuring machine is simple, there is no problem. Therefore, it is possible to provide highly accurate products at low cost.

  The measurement of the amount of expansion and contraction (FIGS. 4 to 7) was carried out using Mitutoyo Corporation, contour shape measuring instrument “SV-C624” and OKM (Germany) high-precision measuring instrument ULM OPAL1000.

  The minute displacement control device according to the present invention can be applied to optical equipment, precision processing machines, laser equipment, measuring instruments, and other equipment in various fields that require minute and precise displacement and feeding. It can be suitably applied to hardness measurement of thin films that are difficult to measure, measurement of specific physical properties such as elastic modulus, creep characteristics, Young's modulus, calibration of a micro displacement sensor, micro positioning stage, and the like.

It is a schematic block diagram of the micro displacement control apparatus which concerns on one embodiment of this invention. It is a schematic block diagram of the micro displacement control apparatus which concerns on another embodiment of this invention. It is a schematic block diagram of the micro displacement control apparatus which concerns on another embodiment of this invention. It is an expansion-contraction characteristic figure of the giant magnetostrictive element under various conditions. It is an expansion-contraction characteristic figure of the giant magnetostrictive element by various magnets. It is an expansion-contraction characteristic figure of a giant magnetostrictive element at the time of moving a magnetic force generation means to a perpendicular | vertical direction with respect to the expansion-contraction direction of a giant magnetostrictive element. It is a characteristic view which shows an example of the hysteresis of the expansion-contraction amount of a giant magnetostrictive element. It is a schematic block diagram which shows an example of the arrangement | sequence by magnetic permeability. It is a schematic block diagram of an ultra micro hardness measuring machine. It is a characteristic view which shows an example of a pushing amount-load characteristic curve.

Explanation of symbols

1 Block 2 Giant Magnetostrictive Element 3 Micrometer or Stepping Motor Unit 3a Micrometer 3b Stepping Motor Unit 4 Permanent Magnet 5 Base 6 Lid 7 Shaft 8 Push Rod 9 Plate 10 Spring 11 Yoke 12 Rotating Plate 13 Cam Bearing 14 Shaft Holder 15 Slide Guide 16 Slide guide 17 Circular cam 21 Minute displacement control device 22 Permanent magnet 23 micrometer 24 Device fixed base 25 Measurement sample 26 Z-axis stage 27 Electronic balance 28 Base panel 29 Anti-vibration rubber 30 Indenter 31 Gate frame

Claims (20)

  A device for controlling expansion and contraction of a giant magnetostrictive element in which one end is fixed and the other end is freed by causing a magnetic force to act on the giant magnetostrictive element to expand and contract the giant magnetostrictive element and output the displacement of the free end. In addition, a rod-shaped super magnetostrictive element is arranged in a block made of a non-magnetic material, and a magnetic force generating means using only a permanent magnet is arranged on the fixed end side of the super magnetostrictive element, and the magnetic force generating means is moved by the moving means. Giant magnetostriction is made by continuously controlling the relative positional relationship between the magnetic force generating means and the giant magnetostrictive element so that the giant magnetostrictive element is continuously expanded and contracted and the displacement is output to the free end side of the giant magnetostrictive element. A micro displacement control apparatus using an element expansion / contraction control apparatus, wherein a target micro displacement is obtained by a displacement output to a free end side of the giant magnetostrictive element.   The minute displacement control device according to claim 1, wherein the magnetic force generating means is disposed on an axis of the giant magnetostrictive element.   3. The minute displacement control device according to claim 1, wherein the moving means comprises means for moving the magnetic force generating means in a direction parallel to the expansion / contraction direction of the giant magnetostrictive element.   The minute displacement control device according to claim 1 or 2, wherein the moving means comprises means for moving the magnetic force generating means in a direction perpendicular to the expansion and contraction direction of the giant magnetostrictive element.   The minute displacement control device according to any one of claims 1 to 4, wherein the moving means includes means for rotating the magnetic force generating means.   On the free end side of the giant magnetostrictive element, there is provided a push rod made of a magnetic material that is displaced along with expansion and contraction of the giant magnetostrictive element, and the arrangement of the components from the magnetic force generating means is from the one with lower magnetic permeability The minute displacement control device according to any one of claims 1 to 5, wherein the minute displacement control device is sequentially performed in a higher order.   7. The minute displacement control device according to claim 6, wherein the push rod side and the magnetic force generating means side are connected by a yoke made of a magnetic material, and a magnetic closed circuit is formed therebetween.   The minute displacement control device according to claim 6 or 7, wherein at least one slide guide connected to the push rod and guiding the push rod in the expansion / contraction direction of the giant magnetostrictive element is provided in the block.   The micro displacement control device according to any one of claims 1 to 8, wherein means for prestressing the giant magnetostrictive element from a free end side of the giant magnetostrictive element is provided.   10. The lid according to claim 1, wherein the block is connected to a fixed end of the giant magnetostrictive element, and is provided with a cover made of a nonmagnetic material and interposed between the fixed end and the magnetic force generation means. A micro displacement control device according to claim 1.   The micro displacement control device according to claim 1, wherein the block is made of a nonmagnetic material having low thermal conductivity.   The micro displacement control device according to claim 1, wherein the block is provided with heating means.   The micro displacement control device according to claim 1, wherein the block is provided with a cooling means.   The micro displacement control device according to any one of claims 1 to 13, wherein a magnetic force measurement device is provided on the push rod on the side of the anti-super magnetostrictive element.   The displacement output to the free end side of the giant magnetostrictive element by the expansion and contraction control device of the giant magnetostrictive element in the minute displacement control apparatus according to any one of claims 1 to 14 is set as an indentation amount into the object to be measured, and load measurement is performed. An apparatus for measuring hardness or the like, characterized in that a load corresponding to the indentation amount is measured using an apparatus to obtain an indentation amount-load characteristic of an object to be measured.   By comparing the displacement output to the free end side of the giant magnetostrictive element by the expansion / contraction control device of the giant magnetostrictive element in the micro displacement control apparatus according to any one of claims 1 to 14 with the output of the target displacement sensor. An apparatus for calibrating a displacement sensor, wherein the output of the target displacement sensor is calibrated.   The stage is positioned by the displacement output to the free end side of the giant magnetostrictive element by the expansion and contraction control device of the giant magnetostrictive element in the micro displacement control apparatus according to any one of claims 1 to 14. A positioning stage.   The amount of indentation into the object to be measured is controlled by the displacement output to the free end side of the giant magnetostrictive element by the expansion and contraction control device of the giant magnetostrictive element using the minute displacement control apparatus according to any one of claims 1 to 14. And measuring a load corresponding to the indentation amount using a load measuring device to obtain an indentation amount-load characteristic of the object to be measured.   Using the minute displacement control device according to any one of claims 1 to 14, the displacement output to the free end side of the giant magnetostrictive element by the expansion and contraction control device of the giant magnetostrictive element is compared with the output of the target displacement sensor. And calibrating the output of the target displacement sensor, thereby calibrating the displacement sensor.   The micro displacement control device according to any one of claims 1 to 14, wherein the stage is positioned by a displacement output to a free end side of the super magnetostrictive element by the expansion / contraction control device of the super magnetostrictive element. A method for controlling the positioning stage.

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