JP2005265788A - Stress measuring method for microtome, and stress measuring instrument for microtome - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stress measuring method for a microtome and a stress measuring instrument for the microtome capable of evaluating mechanical strength, adhesion strength, a surface property and the like of a biomaterial, an industrial material, a laminate thereof, an inter-different-substance interface, a fine particle, an anisotropic sample, an ultrathin film or the like. <P>SOLUTION: Vertical-directional cutting force generated when cutting a sample along a vertical direction, and horizontal-directional force right-angled to the cutting force are detected respectively by a stress conversion means to find by computation a characteristic value of the sample, for example, a friction coefficient applied on the sample, an average vertical stress on a shearing face and average shearing force, together with a cutting width, a set thickness and the like. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention cuts samples for evaluating the mechanical strength, adhesion strength, surface properties, etc. of biomaterials, industrial materials, and laminates thereof, heterogeneous material interfaces, fine particles, anisotropic samples, ultrathin films, etc. A microtome capable of measuring the cutting force and the stress perpendicular to the cutting force and determining the coefficient of friction of the sample, the average normal stress on the shear surface, and the average shear force along with the characteristic value of the sample The present invention relates to a stress measuring method for a microtome and a stress measuring apparatus for a microtome.

  The present invention is an industrial material such as a color film photograph, liquid crystal, polymer, phenol resin, nylon (trade name), polyethylene, plastic lens, coating film, emulsion, aluminum foil, anodized foil, gold foil, metal multilayer film, semiconductor multilayer film. Film, plated foil, fine wire, ultrafine particle, catalyst, phosphor, toner for copying, carbon fiber, magnetic tape, magnetic card, commuter pass, flexible disk, optical disk, prepaid card, artificial kidney, hollow fiber, bone, tooth, hair The present invention relates to a microtome stress measurement method and a microtome stress measurement apparatus for evaluating the mechanical strength, adhesion strength, and the like of printing paper, rubber gaskets, photosensitive materials, and the like, and laminates thereof.

  Hereinafter, a method for using the microtome will be described. Conventionally, the evaluation of living tissue and the like has been performed by extracting a living tissue and solidifying it with a resin member by a predetermined method into a thin section by cutting with a microtome, and this thin section is placed on a grid surface made of a metal net. It was carried out by placing and observing with an electron microscope.

  In the microtome, a portion to which a sample is fixed moves up and down, and is cut as a thin slice by a fixed knife. In addition, the portion to which the sample is fixed can be moved to move up and down to a predetermined position. Then, the operator sets the positional relationship while looking into the sample with an electron microscope, and then automatically or manually cuts the sample.

  In particular, dissimilar materials with biological tissues such as stainless steel, cobalt-chromium alloy, pure titanium and titanium alloy, plastic members such as nylon (trade name) and polyester, composites of natural collagen and synthetic polymer, apatite (trade name) It is necessary to evaluate the interfacial adhesion.

  The material is, for example, a plate of 3 mm × 2 mm × 0.5 mm, and its surface is nicked and embedded in the rabbit's or dog's thigh muscle tissue or greater gluteal muscle. The material is removed from a rabbit or dog 4 weeks, 12 weeks, or 24 weeks after implantation.

  In order to evaluate the interfacial adhesion between the material and the tissue, the extracted material is solidified with a resin by a predetermined method. The extracted material solidified by the resin is cut as a thin section by a microtome as a sample, and placed on the surface of a grid made of a metal net so as to be easily observed by an electron microscope.

  In the case of the industrial material, similarly, the mechanical strength can be evaluated by observing a sample cut so that the cross section of the material and the interface state of the laminate can be understood. It is necessary to evaluate the peel strength when an industrial material such as gold-aluminum-copper is bonded to a polyester substrate, the interface strength between the materials, and the like.

  The sample made of the cut thin section is subjected to a material deterioration test, a corrosion fatigue test, an abrasion resistance test and the like in order to evaluate the mechanical compatibility. In the material deterioration test, metal materials or metal ions used as biomaterials are eluted from the surface after long-term use, and their function decreases, or the dissolution behavior of the implant during long-term use (corrosion resistance) Is evaluated electrochemically.

  In the corrosion fatigue test, the implant used for the artificial bone / artificial joint is repeatedly subjected to stress along with corrosion, and therefore, the evaluation is performed under a condition that reproduces the “in vivo environment” in which fatigue fracture occurs during long-term use.

  Biomaterials rub against body tissue such as the approaching bone. In the case of a device composed of a plurality of materials, frictional wear between the materials occurs. The wear resistance test (friction wear) is evaluated using a sample made of a thin section obtained by cutting the biomaterial and the device.

  The biocompatibility includes cell compatibility evaluation and tissue compatibility, and the compatibility of the metal ions and wear powder eluted from the biomaterial with respect to the living body is evaluated using cells. Biocompatibility can be estimated from the results of animal experiments and clinical results from test results using cells if the causal relationship between degradation of biomaterials and effects on living organisms can be estimated at the cellular level. This leads to high reproducibility of test results.

  Biomaterials need to be analyzed for trace substances in simulated body fluids. Biomaterials deteriorate and corrode after long-term use, and trace substances are eluted. Since the trace substance affects the human body by long-term elution, it is necessary to establish a method for quantifying the trace substance in the in-vivo environmental fluid.

  In addition, in the method for evaluating the biocompatibility of the biomaterial, there is a demand for the specimen made of the thin section to know the mechanical characteristics such as cutting energy and stress when being cut into the thin section. This demand is because it is necessary to quantitatively evaluate the mechanical characteristics of the artificial biomaterial or the adhesiveness of the interface between the living tissue and the embedded foreign substance. Examples of the different substances include bone and metal, or muscle and polymer material.

  Next, a conventional microtome stress measuring device (Japanese Patent No. 2986157) will be described. FIG. 8 is a cross-sectional view of a conventional microtome stress measuring apparatus. In FIG. 8, the stress measurement unit 71 uses, for example, a sample S for producing a thin slice sample for evaluating the mechanical properties of a biomaterial, an industrial material, or a laminate made of these materials embedded in a living body. When cutting, it is a part that accurately measures the stress at the time of cutting.

  The stress measuring unit 71 includes a mounting base (not shown), a stress transmission member holder 72, an L-shaped stress transmission member 74, and a high sensitivity force transducer 80 as main components.

  The mounting base attached to the microtome is configured so that the sample S can be set at a predetermined position, and the sample S can be moved in the vertical direction to apply cutting or force. . A stress transmission member holder 72 is detachably attached to the attachment base by means of attachment screws 73.

  The stress transmission member holder 72 is fixed so that the L-shaped stress transmission member 74 is not shaken by a screw (not shown). Since the L-shaped stress transmission member 74 is fixed so as not to sway by the screw, the stress applied to the sample S can be transmitted to the high-sensitivity force transducer 80.

  The L-shaped stress transmission member 74 can firmly fix the sample S so that the sample pressing screw 751 can move in the vertical direction on the vertical portion 74 ′. The sample presser screw 751 is provided with a sample presser plate 75 at the lower part thereof. A lower sample mounting table 76 is provided at a position facing the sample pressing plate 75.

  The sample holding screw 751 is attached to the vertical portion 74 ′ of the L-shaped stress transmission member 74 by a sample holding screw attaching plate 752. The sample S is sandwiched between the lower sample mounting table 76 by lowering the sample pressing plate 75. The L-shaped stress transmission member 74 has a support member 781 that supports the stress adjusting member 78 at the center of the lower portion thereof.

  The stress adjusting member 78 can adjust the stress by a stress adjusting screw 79 via a support member 781. A high sensitivity force transducer 80 supported by a transducer holder 77 is provided on the stress adjusting member 78.

  The L-shaped stress transmission member 74 is provided with a gap 741 between the vertical portion 74 ′ into which the sample holding screw 751 is inserted and the side surface of the transducer holder 77, and the stress applied to the sample S is highly sensitive. The structure is such that it is accurately transmitted to the converter 80.

  Further, a gap 721 is provided between the end portion 74 ″ of the L-shaped stress transmission member 74 and the stress transmission member holder 72. These gaps 721 and 741 are 1 mm or less. The L-shaped stress transmission member 74 facilitates transmission of the stress of the sample S. The stress is accumulated as data, and an undesired force is applied when the sample S is used as the sample. Whether or not the sample is inappropriate can be determined.

  Since the L-shaped stress transmission member 74 is an L-shaped ridge, the stress applied to the sample S is not absorbed by the sample pressing plate 75, the sample pressing screw 751, and the like, and the high-sensitivity force transducer 80 is used. Communicated. The L-shaped stress transmission member 74 has a stress at the time when the sample S is subjected to cutting or force because the sample pressing screw 751 presses the sample S from the upper side to the lower side at the vertical portion 74 ′. Is not absorbed upward and is accurately transmitted to the high-sensitivity force transducer 80.

  A knife 81 attached so as to be fixed separately from a base (not shown) to which the stress measurement unit 71 is attached is cut as a thin slice 82 by the vertical movement of the tip of the sample S. it can. The stress at the time of cutting is transmitted to the high-sensitivity force transducer 80 through the sample pressing plate 75, the L-shaped stress transmission member 74, and the stress adjustment member 78.

  Further, the cut thin section 82 floats on the upper surface of the water stored in the water reservoir 83 formed in the knife 81. The thin slice 82 floating on the water surface is placed on the surface of a grid (not shown) made of a metal net, and becomes a sample that can be easily observed by an electron microscope.

  FIG. 7 is a diagram for explaining a cutting force and a profile during cutting when pure aluminum is cut. In FIG. 7, when the microtome stress measuring apparatus cuts pure aluminum, the cutting force FC is detected from the moment when the cutting blade hits until the cutting is completed.

The stress measuring apparatus for microtome is described in detail in Japanese Patent Application Laid-Open Nos. 2001-324423, 2003-322600, and 2003-322601.
JP 2001-324423 A JP 2003-322600 A JP 2003-322601 A

  The cutting force measured by the conventional microtome stress measuring device does not necessarily reflect the mechanical properties of the material. As a result of the applicant's research, it has been found that the cutting force is not necessarily correlated with the Vickers hardness, which is an index of the hardness of the material.

  In particular, it has been found that materials that have been cold worked or heat treated are not correlated with the cutting force. Therefore, as a result of considering that the cutting force is composed of the shearing force and the peeling force of the material, the present applicant shows a unique value for the material without depending on the hardness of the material. It was found that there is a good correlation with the rigidity.

  The present invention is for solving the above-mentioned drawbacks. From the cutting force and the stress in the direction perpendicular to the cutting force, the cutting width and the set thickness of the cutting piece, etc., the average normal stress on the shear plane, and It is an object of the present invention to provide a microtome stress measurement method and a microtome stress measurement apparatus capable of obtaining an average shear force.

(First invention)
The stress measurement method for microtome according to the first aspect of the present invention includes biomaterials, industrial materials, and laminates thereof, heterogeneous material interfaces, fine particles, anisotropic samples, ultrathin films, etc., mechanical strength, adhesion strength, surface properties, etc. It is for evaluation, and a vertical cutting force generated when the sample is cut in the vertical direction and a horizontal force perpendicular to the cutting force are detected by the stress conversion means, respectively. The friction coefficient applied to the sample, the average normal stress on the shear plane, and the average shear force are measured.

(Second invention)
The stress measuring apparatus for microtome according to the second invention comprises biomaterials, industrial materials, and laminates thereof, heterogeneous material interfaces, fine particles, anisotropic samples, ultrathin films, etc., mechanical strength, adhesion strength, surface properties, etc. The stress applied to the sample for evaluation is measured. The fixing means for fixing the sample, the fixed cutting blade for cutting the slice of the sample by moving the sample up and down, and the sample cutting in the vertical direction A first high-sensitivity force transducer that detects cutting stress when the sample is cut; a second high-sensitivity force transducer that detects horizontal stress when the sample is cut; and a characteristic value of the sample is input A stress detected by the input means, the first and second high-sensitivity force transducers, a coefficient of friction applied to the sample based on the characteristic value input by the input means, an average normal stress on the shear plane, And mean shear Characterized in that it comprises at least a calculating means for calculating, for the.

(Third invention)
According to a third aspect of the present invention, there is provided the microtome stress measuring device according to the second aspect of the present invention, through the stress detection block in which the cutting force when cutting the sample fixed by the fixing means is suspended from the first high-sensitivity force transducer. And detected by the first high sensitivity force transducer and the second high sensitivity force transducer.

(Fourth invention)
According to a fourth aspect of the present invention, there is provided the microtome stress measuring device according to the second aspect, wherein the first high-sensitivity force transducer and the second high-sensitivity force transducer are fixed by the holders, and The tip is in contact with the stress detection block.

(Fifth invention)
The stress measuring apparatus for a microtome according to a fifth invention is characterized in that, in the second invention, the stress detection block is attached to the end of the first high-sensitivity force transducer by a preload screw arranged at the center thereof.

(Sixth invention)
The stress measuring apparatus for a microtome according to a sixth aspect of the present invention is characterized in that, in the second aspect, the second high-sensitivity force transducer is provided with a horizontal preload means in the stress detection block.

  According to the present invention, the cutting force in the microtome stress measuring device is detected by the high-sensitivity force transducer in the vertical direction and the high-sensitivity force transducer in the horizontal direction, and based on the cutting width and set thickness of the sample, Average normal stress and average shear stress on the shear plane can be determined, and material-specific properties independent of material hardness can be found.

  According to the present invention, the stress detection block for transmitting cutting force in the stress measuring apparatus for microtome, and the shape and fixing method of the holder that fixes the high sensitivity force transducer in the vertical direction and the high sensitivity force transducer in the horizontal direction are devised. Thus, the high-sensitivity force transducer in the vertical direction and the high-sensitivity force transducer in the horizontal direction can measure the correct stress, and the average normal stress and the average shear stress on the shear plane can be obtained more accurately. It is possible to find material-specific properties that do not depend on the hardness of the material.

  According to the present invention, by establishing a cutting force Fc and a method for measuring a force Ft perpendicular to the cutting force Fc, the cutting conditions for the cutting force (for example, the cutting speed, the frictional force between the knife and the sample, the knife Now, it is possible to clarify the influence of the blade edge angle.

(First invention)
The stress measurement method for microtome according to the first aspect of the present invention includes biomaterials, industrial materials, and laminates thereof, heterogeneous material interfaces, fine particles, anisotropic samples, ultrathin films, etc., mechanical strength, adhesion strength, surface properties, etc. This is for evaluation. By measuring the cutting force and the force perpendicular to the cutting force, the friction coefficient applied to the sample, the average normal stress on the shear plane, and the average shear force can be obtained. is there.

  The stress measuring method for a microtome according to the first aspect of the invention detects, by a stress conversion means, a vertical cutting force generated when the sample is cut in a vertical direction and a horizontal force perpendicular to the cutting force. In addition to the characteristic values of the sample, for example, the cutting coefficient, the set thickness, etc., the coefficient of friction applied to the sample, the average normal stress on the shear plane, and the average shear force can be obtained by calculation.

  The stress measurement method for microtome according to the first aspect of the present invention is based on shear force even if the metal does not have a good correlation between cutting force and shear force, for example, metal whose hardness is changed by cold working or heat treatment. The material properties can be evaluated.

(Second invention)
A stress measuring apparatus for microtome according to a second aspect of the present invention includes a sample fixing means, a fixed cutting blade, a high-sensitivity force transducer for detecting vertical and horizontal cutting forces, an input means for inputting sample characteristics, It is comprised from the value detected by the high sensitivity force converter and the value by an input means from the calculating means which calculates the friction coefficient concerning a sample, the average normal stress on a shear plane, and an average shear force.

  The stress measuring apparatus for microtome according to the second aspect of the present invention can determine the coefficient of friction applied to the sample, the average normal stress on the shear plane, and the average shear force, so that biomaterials, industrial materials, and laminates thereof, The mechanical strength, adhesion strength, surface properties, etc. of different substance interfaces, fine particles, anisotropic samples, ultrathin films, etc. can be evaluated. A specific calculation method by the calculation means will be described in detail in the embodiments described later.

  The fixing means for fixing the sample can move the sample up and down, and the sample section is cut by hitting the fixed cutting blade. The first high-sensitivity force transducer detects a cutting force when the sample comes down and hits the fixed blade. The second high-sensitivity force transducer detects a horizontal force when the cutting force is generated.

  The input means is input with characteristic values such as the cutting width and set thickness of the sample. Based on the force detected by the first and second high-sensitivity force transducers and the characteristic value input by the input means, the calculation means calculates the coefficient of friction applied to the sample, the shear surface The average normal stress and the average shear force are calculated.

(Third invention)
The stress measuring apparatus for a microtome according to the third aspect of the present invention is configured so that the cutting force when cutting the sample fixed by the fixing means is transmitted to the first high sensitivity force transducer and the second high sensitivity force transducer. It is detected via a stress detection block suspended from the first high sensitivity force transducer. Since the stress detection block is suspended in the space and is in contact with the end portions of the first high sensitivity force transducer and the second high sensitivity force transducer, the cutting force is faithfully detected.

(Fourth invention)
In the stress measuring apparatus for microtome according to the fourth aspect of the invention, the first high-sensitivity force transducer and the second high-sensitivity force transducer are fixed by holders such as an inverted L shape or a U-shaped cross section. In addition, each of the first high-sensitivity force transducer and the second high-sensitivity force transducer is in contact with the stress detection block through the space portion of the holder. According to the fourth aspect of the present invention, only the end of the high-sensitivity force transducer and the stress detection block are brought into contact with each other in the gap, so that subtle force conversion can be accurately detected.

(Fifth invention)
In the stress measuring apparatus for microtome according to the fifth aspect of the invention, the stress detection block is attached to the end of the first high-sensitivity force transducer by a preload screw arranged at the center thereof. The preload screw can improve the sensitivity of the cutting force by applying the preload screw in a direction in which a force is applied to the first high-sensitivity force transducer or a direction in which the force is pulled. The direction in which the preload is applied depends on whether the output of the high-sensitivity force transducer is positive or negative, and can be changed to a convenient direction by the calculation means.

(Sixth invention)
The high sensitivity force transducer according to the sixth aspect of the invention improves the sensitivity by preloading the second high sensitivity force transducer in the horizontal direction. That is, the preload in the horizontal direction increases the sensitivity by applying the pressure at which the second high-sensitivity force transducer contacts the stress detection block in the positive or negative direction, for example, by rotating a nut. .

  FIG. 1 is a view for explaining the principle in the stress measuring apparatus for microtome according to the present invention. In FIG. 1, the stress measurement unit is composed of, for example, a square stress detection block 11 and an inverted L-shaped holder 12. The stress detection block 11 is disposed in the gap portion 123 of the inverted L-shaped holder 12.

  The stress detection block 11 is provided with a screw hole 111 at the center, a preload screw 15 is screwed in, and a screw at the tip is also in a screw hole 133 provided at an end of the vertical high-sensitivity force transducer 13. It is attached in a suspended state by being screwed. Further, the preload screw 15 can increase the sensitivity in the vertical direction by the force screwed into the vertical high sensitivity force transducer 13.

  The stress detection block 11 fixes the sample 16 to the center in the left direction shown in FIG. The sample 16 can be reciprocated in the vertical direction by means not shown, and is cut into thin pieces by a fixed knife 17.

  The inverted L-shaped holder 12 has a vertical high-sensitivity force transducer 13 fixed to a horizontal portion and a horizontal high-sensitivity force transducer 14 fixed to the vertical portion by flanges 131 and 141, respectively. The inverted L-shaped holder 12 has a vertical screw hole 121 and a horizontal screw hole 122, the vertical high-sensitivity force converter 13 has a screw 132, and the horizontal high-sensitivity force converter 14 has a screw. , Screws 142 are respectively provided.

  The vertical high-sensitivity force transducer 13 and the horizontal high-sensitivity force transducer 14 are screwed into the vertical screw holes 121 and the horizontal screw holes 122 and firmly fixed by the flanges 131 and 141, respectively. .

  The vertical high-sensitivity force transducer 13 is in contact with the upper center surface 112 of the stress detection block 11 at the tip. The tip of the horizontal high-sensitivity force transducer 14 is in contact with the lateral center plane 113 of the stress detection block 11.

によって、摩擦係数：μ、せん断面上での平均垂直応力：σ_s 、平均せん断応力：τ_s が求められる。 FIG. 2 is a view for explaining a cutting mechanism in the microtome stress measuring apparatus of the present invention. In FIG. 2, rake angle: α, shear angle: Φ, cutting edge angle: θ, clearance angle: γ, set thickness: t ₁ , intercept width: b,

Thus, the friction coefficient: μ, the average normal stress on the shear plane: σ _s , and the average shear stress: τ _s are obtained.

  That is, the present invention establishes a cutting force Fc and a method for measuring a force Ft (see FIG. 2) perpendicular to the cutting force Fc, so that the cutting conditions for the cutting force (for example, cutting speed, between knife and sample) Frictional force, knife edge angle, etc.) can be clarified. In addition, the present invention has established a cutting mechanism in the microtome, and can measure the shear stress in the material.

  FIG. 3 is a view for explaining the structure of a microtome stress measuring apparatus according to an embodiment of the present invention. FIG. 4 is a side view of the microtome stress measuring apparatus in FIG. 3 and 4, the microtome stress measuring apparatus includes a vertical high-sensitivity force transducer assembly 21, a horizontal high-sensitivity force transducer assembly 22, a stress transmission assembly 23, and a sample attachment for attaching a sample. An assembly 24 and a holder 25 are included.

  The vertical high-sensitivity force transducer assembly 21 has a vertical high-sensitivity force converter 13 attached in a vertical cylindrical portion 251 of a holder 25 and a horizontal high-sensitivity force in a horizontal cylindrical portion 252. The converter 14 is attached by, for example, screws.

  The horizontal high-sensitivity force transducer assembly 22 is inserted into the horizontal cylindrical portion 252 holding the horizontal high-sensitivity force transducer 14 and screwed, and then the nut 26 is rotated to rotate the horizontal direction. The tip of the high sensitivity force transducer 14 abuts on a stress detection block 231 described later. The contact pressure of the horizontal high-sensitivity force transducer 14 against the stress detection block 231 can be adjusted by the rotation of the nut 26, and the detection sensitivity in the horizontal direction can be improved as a preload.

  The stress transmission assembly 23 includes a stress detection block 231 and a preload screw 232 that suspends the stress detection block 231 from the vertical high-sensitivity force transducer 13. The preload screw 232 preloads the end of the vertical high-sensitivity force transducer 13 by screwing into the screw hole of the stress detection block 231 to improve the detection sensitivity in the vertical direction.

  The sample mounting assembly 24 includes a rotating mechanism 241 that can change the angle in order to mount the sample 16 at a correct position, and a fixing unit 242 that fixes the sample 16.

  The sample 16 is lowered by a mechanism (not shown) and abuts against a knife edge (not shown). The cutting force generated when the cutting edge abuts is transmitted to the vertical high-sensitivity force transducer 13 with the force point 31, a fulcrum 32 of a portion not shown, and the central portion of the stress detection block 231 acting as the action point 33. , Detected as Fc shown in FIG.

Similarly, Ft shown in FIG. 2 is detected by the horizontal direction high sensitivity force converter 14. By substituting the above Fc and Ft, Φ, α, cutting width: b, set thickness: t ₁ in FIG. 2 into the above [Formula 1], and calculating the friction coefficient μ, on the shear plane, Average normal stress: σ _s and average shear stress: τ _s are obtained.

FIG. 5 is a block diagram for calculating a shear force by a sample determination device in a microtome according to an embodiment of the present invention. In FIG. 5, the microtome stress measuring device includes a vertical movement amount detecting means 511 for detecting a vertical movement amount of the sample 16, a vertical high-sensitivity force converter 512 for detecting a cutting force applied to the sample 16, A / D conversion means 513 for converting the outputs of the vertical direction moving amount detection means 511 and the vertical high sensitivity force converter 512 into digital data, and the digital data converted by the A / D conversion means 513 are temporarily stored. Vertical direction first storage means 514, vertical direction reference value input / capture means 515 for inputting a known reference amount, and information input by the vertical direction reference value input / capture means 515 are converted into digital data. A / D conversion means 516 for converting, and the second vertical direction for temporarily storing the digital data obtained by the A / D conversion means 516 Means 517, first comparison means 518 for comparing the digital data stored in the vertical first storage means 514 with the digital data stored in the vertical second storage means 517, and the first comparison The first determination means 519 for determining whether or not Fc shown in FIG. 2 as a comparison result of the means 518 is within a certain range, similarly, the horizontal high-sensitivity force converter 521 for the horizontal direction, and A / D conversion Means 522, horizontal direction first storage means 523, horizontal direction reference value input / take-in means 524, A / D conversion means 525, horizontal direction second storage means 526, horizontal direction first storage means 523 and horizontal direction first 2 is a comparison result of the second comparison means 527 for comparing the digital data stored in the storage means 526, and Ft shown in FIG. A second determination unit 528 determines whether a囲内a known value shown in FIG. 2 alpha, [Phi, gamma, b, an input means 531 for inputting a t _1, detected by the microtome for stress measurement device Calculating means 532 for calculating the friction coefficient μ, the average shear stress σ _s on the shear plane, and the average shear force τ _s from the Fc and Ft values and the values of the input means 531, the friction coefficient μ, And an output means 533 for outputting an average shear stress σ _s and an average shear force τ _s on the cross section.

  Information on the position information of the blade generated when the sample 16 is cut, or information on mechanical characteristics, etc. is detected by the vertical movement amount detecting means 511 that detects a temporal change in stress as an electrical signal, If necessary, the data is temporarily stored in the vertical first storage unit 514 as digital data by the A / D conversion unit 513 via the amplification unit.

  The reference amount that is known in advance is input from the vertical direction reference value input / capture unit 515, and then converted into digital data by the A / D conversion unit 516 via the amplification unit as necessary as described above. Temporarily stored in the vertical second storage means 517.

The first comparison means 518 compares the digital data in the vertical first storage means 514 with the digital data in the vertical second storage means 517. When the first determination means 519 determines that the comparison result of the first comparison means 518 is within a certain range, the first determination means 519 determines that the sample 16 is in a certain quality and uses the calculation means as data Fc. Output to 532. Ft in the horizontal direction is input to the calculation means 532 as described above. Thereafter, the calculation means 532 performs calculation based on the equation 1, and outputs the friction force μ, the average shear stress σ _s on the shear plane, the average shear force τ _{s, and the} like from the output means 533. .

  FIG. 6 is a view for explaining the structure of a stress measuring apparatus for microtome according to another embodiment of the present invention. The embodiment shown in FIG. 6 is a modification of the stress measuring apparatus for microtome shown in FIG. 3, and the shapes of the stress transmission assembly 23 'and the holder 25' are different. That is, the stress transmission assembly 23 'is formed in a U-shape, the U-shaped opening is directed upward, and the sensor portion of the vertical high-sensitivity force transducer assembly 21 is in contact with the opening. ing.

  The holder 25 'is formed in an L-shape with the orientation as shown in the figure, and a vertical high-sensitivity force transducer assembly 21 is provided in the horizontal portion. Further, a horizontal direction high sensitivity force transducer assembly 22 is attached to the vertical portion of the holder 25 ′, and the sensor portion of the horizontal direction high sensitivity force transducer 22 is the U-shaped stress transmission assembly 23. Is in contact with the side of ′. The sample 16 is fixed by fixing means 242 'provided at the lower part of the U-shaped stress transmission assembly 23'.

  As mentioned above, although the present Example was explained in full detail, this invention is not limited to the said Example. Various design changes can be made without departing from the scope of the present invention. For example, the high-sensitivity force conversion memory may be a known or well-known force-electric conversion means such as a crystal, a strain gauge, a capacitance, a manometer, or the like that converts strain displacement into an electrical signal.

  The shape of the holder for mounting the high-sensitivity force transducer and the stress detection block for detecting the stress can be changed without departing from the scope of the present invention.

  The “microtome” in the embodiment of the present invention includes “ultramicrotome” and “instrumented ultramicrotome”. Furthermore, the present invention can be applied to substances other than those specifically described in the present specification, and other than the mechanical strength, interfacial adhesion strength, surface properties, etc., as long as mechanical characteristics are utilized. It goes without saying that things can be evaluated.

It is a figure for demonstrating the principle in the stress measuring apparatus for microtomes of this invention. It is a figure for demonstrating the cutting mechanism in the stress measuring apparatus for microtomes of this invention. In one Example of this invention, it is a figure for demonstrating the structure of the stress measuring apparatus for microtomes. (Example 1) FIG. 4 is a left side view of the microtome stress measuring device in FIG. 3. In the Example of this invention, it is a block block diagram for calculating a shear force with the sample determination apparatus in a microtome. It is a figure for demonstrating the structure of the stress measuring apparatus for microtomes in the other Example of this invention. (Example 2) It is a figure for demonstrating the cutting force at the time of cutting pure aluminum, and the profile in process of cutting. It is sectional drawing of the conventional stress measuring apparatus for microtomes.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Stress detection block 111 ... Screw hole 112 ... Upper center plane 113 ... Horizontal center plane 12 ... Reverse L-shaped boulder 121 ... Vertical screw hole 122 ... Horizontal direction Screw hole 123 ... Gap 13 ... Vertical high sensitivity force transducer 131 ... Flange 132 ... Screw 133 ... Screw hole 14 ... Horizontal high sensitivity force transducer 141 ... Flange 142 ... Screw 15 ... Preload screw 151 ... Screw 16 ... Sample 161 ... Fixing means 17 ... Knife 21 ... Vertical sensitive force transducer assembly 22 ... Horizontal high-sensitivity force transducer assembly 23 ... Stress transmission assembly 231 ... Stress detection block 232 ... Preload screw 24 ... Sample mounting assembly 241 ... Rotating mechanism 242 ... Fixing means 25. ..Holder 26 ... Nut 251 ... Vertical cylindrical portion 252 ... Horizontal cylindrical portion 253 ... Gap portion 31 ... Power point 32 ... Support point 33 ... Operation point

Claims (6)

In the stress measurement method for microtome for evaluating the mechanical strength, adhesion strength, surface properties, etc. of biomaterials, industrial materials, and laminates thereof, heterogeneous material interfaces, fine particles, anisotropic samples, ultrathin films, etc.
The friction coefficient applied to the sample by detecting the vertical cutting force generated when cutting the sample in the vertical direction and the horizontal force perpendicular to the cutting force by the stress conversion means, A stress measuring method for a microtome, characterized by measuring an average normal stress and an average shear force on a shear plane. Measure the stress on biological materials, industrial materials, and laminates, heterogeneous material interfaces, fine particles, anisotropic samples, ultrathin films, etc. to evaluate the mechanical strength, adhesion strength, surface properties, etc. In the stress measuring device for microtome,
Fixing means for fixing the sample;
A fixed cutting blade that cuts a section of the sample by moving the sample up and down;
A first high-sensitivity force transducer for detecting a cutting stress when the sample is cut in a vertical direction;
A second highly sensitive force transducer for detecting a horizontal stress when the sample is cut;
Input means for inputting the characteristic value of the sample;
Based on the stress detected by the first high-sensitivity force transducer and the second high-sensitivity force transducer, the coefficient of friction applied to the sample based on the characteristic value input by the input means, and the average normal stress on the shear plane , And calculation means for calculating the average shear force;
A stress measuring apparatus for a microtome, comprising:   The cutting force when cutting the sample fixed by the fixing means is a first high-sensitivity force transducer and a second high-sensitivity force via a stress detection block suspended from the first high-sensitivity force transducer. 3. The microtome stress measuring device according to claim 2, which is detected by a transducer.   The first high-sensitivity force transducer and the second high-sensitivity force transducer are fixed by a holder, and each tip portion is in contact with the stress detection block through a space portion of the holder. The stress measuring apparatus for microtomes according to claim 2 or 3, characterized in that it is characterized in that:   5. The stress detection block according to claim 2, wherein the stress detection block is attached to an end portion of the first high-sensitivity force transducer by a preload screw disposed at a center thereof. 6. Stress measuring device for microtome.   6. The microtome stress measurement according to claim 2, wherein the second high-sensitivity force transducer is provided with a horizontal preload means in the stress detection block. 7. apparatus.

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