JPH06160269A - Dynamic viscoelasticity measuring equipment - Google Patents

Abstract

PURPOSE:To allow highly accurate detection of sinusoidal distortion with no thermal effect from heating furnace by measuring displacement of a probe in thrust direction at a part held between two leaf springs through the use of an L-shaped core fixing metal. CONSTITUTION:An L-shaped core fixing metal 7 is secured, at one end thereof, to a part of a probe 4 being secured resiliently through a leaf spring 5 to a housing 14 and a rod 7a penetrates through a hole made through a leaf spring 5 on B side, without contacting therewith, and arranged in parallel therewith. A core 8 and a differential transformer 9 arranged thereabout constitute a detector for detecting displacement in the probe thrust direction. This constitution allows highly accurate detection of distortion of a sample through the transformer 9 even for the stress in radial direction due to micro axial shift at the time of fixing the probe when a sinusoidal stress is applied to the probe 4 in thrust direction. Furthermore, degree of freedom is increased in the fixing position of the core 8 and the transformer 9 susceptible to environmental temperature can be set at a position remote from a heating furnace 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic viscoelasticity measuring device.

[0002]

2. Description of the Related Art In dynamic viscoelasticity measurement, application of stress to a sample 1 and measurement of response strain are all performed through a probe 4. The displacement of the probe 4 in the thrust direction is measured and the strain amount of the probe is corrected to obtain the sample deformation amount. Conventionally, for avoiding the thermal influence from the heating furnace 15 and for the reason of manufacturing, the core 8 forming a pair with the differential transformer 9 is disposed in the middle of the leaf spring 5 and the force generator 30 as shown in FIG. Probe 4
The displacement in the thrust direction of the probe 4 is measured by the relative displacement with respect to the differential transformer 9 which is arranged above and fixed to the housing 14.

[0003]

According to the above-described conventional position of the core 8, when the probe 4 is assembled, if the thrust direction of the probe 4 and the direction of the force generator 30 do not completely coincide with each other, the force generation of the probe 4 is generated. A radial stress component is generated at one end on the device 12 side, and a radial displacement proportional to the distance from the probe fixing portion 13 of the spring 5 to the differential transformer core is centered around the probe fixing portion of the upper spring 5 in FIG. It occurs in the core 8 of the differential transformer. That is, the probe 4 has the point B as a fixed point, and the force generator 30 portion of the probe 4 is bent in the radial direction. Sample 1 with high rigidity
Force is applied to the tip of the probe 4,
When a sine stress is applied to the sample 1 at 12, in the sine strain detected by the differential transformer core, the strain amplitude in the radial direction becomes relatively larger than the strain amplitude in the thrust direction,
There is a problem that the sine distortion detection of the accurate sample is adversely affected.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an L-shaped dynamic viscoelasticity measuring device in which one end is fixed to a probe and the other end is fixed to a differential transformer core. Introducing the core fixing tool, the fixing of the core fixing tool to the probe is made between the two leaf springs, and one side fixing the differential transformer core of the core fixing tool is parallel to the probe. So that
The configuration is such that the displacement in the thrust direction of the probe sandwiched between the two leaf springs can be measured at another position.

[0005]

According to the strain detecting method of the dynamic viscoelasticity measuring device configured as described above, both ends of the probe portion for detecting the displacement in the thrust direction are fixed ends by fixing the plate spring and are displaced in the radial direction. Since it is difficult to do so, the sine distortion of the sample can be detected with high accuracy when detecting with a differential transformer. Since the differential transformer core can be set at any position with the core fixture, it is possible to detect strain in locations that are not easily affected by the thermal influence of the heating furnace when measuring with a differential transformer that is sensitive to temperature changes. It will be possible.

[0006]

【Example】

(Embodiment 1) The present invention will be described in detail below with reference to FIG. 1 showing one embodiment. In the figure, 1 is a sample, and both ends of the sample 1 are fixed and held by a sample holding member 2.
The central portion of is held by the chuck 3. The sample 1 is subjected to a stress, which will be described later, in the radial direction in the central portion of the sample at both fixed ends. The chuck 3 is fixed to the probe 4,
Is a housing with two leaf springs 5 and 5 at the positions A and B.
It is elastically fixed to 14, and the movement of the probe 4 is restricted in a linear (one-dimensional) direction.

Further, one end of an L-shaped core fixture 7 is fixed between the leaf springs 5 and 5, that is, a part of the probe 4 at an intermediate position between A and B in the figure, and the core 8 is attached to the other end. The rod-shaped 7a of the core fixture 7 that is fixed and has the core 8 fixed thereto passes through a hole (not shown) of the leaf spring 5 on the B side in a non-contact manner and is arranged in parallel with the probe 4. The differential transformer 9 arranged around the core 8 and the core 8 constitute a displacement detector for detecting the displacement in the probe thrust direction, and the position of the differential transformer 9 is the micrometer 10 attached to the housing 14. Is determined by

Further, a coil holder 11 is fixed to one end of the probe 4, a coil 12 is fixed to the coil holder 11, and a magnet 13 fixed to a casing 14 so as to surround the coil 12 is arranged. Coil 12 and magnet
13 and the force generator 30 are configured.

On the other hand, a furnace 15 is arranged around the sample 1 for the purpose of setting the temperature environment of the sample 1. Furnace 15
The temperature can be changed according to a certain program in the heating furnace controller 17 by a conventional method. A sample temperature detector 16 measures the sample temperature with a thermocouple (not shown) arranged near the sample.

Reference numeral 21 in the drawing is a sine wave generator, and the output (sine wave) of the sine wave generator 21 is adjusted in amplitude by an amplifier 20, sent to the coil 12, and cooperates with the magnet 13. Generates a sine wave force. The output of the amplifier 20 is
The sine wave force is calculated in the force detection circuit 22.
The calculation of the sine wave force is performed by utilizing the fact that the relationship between the current generated by the amplifier 20 and the force generated by the force generator is related 1: 1 by a method not described in detail.

A displacement detection signal from a displacement detector composed of the differential transformer 9 and the core 8 is sent to a displacement detection circuit 18 and converted into a displacement signal. The force signal output from the force detection circuit 22 and the displacement signal output from the displacement detection circuit 17 are
They are sent to the amplitude ratio / phase difference detector 19, respectively, and the amplitude ratio F ₀ / X _{0 of} force and strain and the phase difference τ are calculated.

For the amplitude ratio and the phase difference, an amount representing the dynamic viscoelasticity of the sample 1 is obtained by an external computer (not shown) according to the following equations. E ^* = E ′ + iE ″ E ′ = | E ^* | cos δ E ″ = | E ^* | sin δ tan δ = E ″ / E ′ │E ^* │ = F ₀ / αX ₀ δ = ω ₀ τ E ^* : complex elasticity Modulus E ′: Storage modulus E ″ Loss modulus δ: Loss angle ω ₀ : Measurement frequency α: Sample shape factor F ₀ : Sinusoidal stress amplitude X ₀ : Sinusoidal strain amplitude τ: Phase difference i: Imaginary device First, the operation of the sine wave generator
A sine wave having a desired frequency is generated by 21, and the amplitude of the sine wave is appropriately adjusted by the amplifier 20, and then the sine wave is sent to the coil 12 to generate a sine wave force in cooperation with the magnet 13. Let That is, the sinusoidal force generated by the force generator 30 is applied to the sample 1 as bending (flexure) stress through the coil holder 11, the probe 4, and the chuck 3. On the other hand, the bending (deflection) strain generated in the sample 1 is transmitted to the core 8 as a displacement in the probe thrust direction through the chuck 3, the probe 4, and the core fixture 7, and detected as a displacement of the core 8 with respect to the differential transformer 9. To be done.

At this time, the displacement of the core 8 is a displacement in the thrust direction of a part of the probe 4 fixed in the radial direction by the two leaf springs 5 and 5 which deform both sides only in the probe thrust direction. Limited to the thrust direction only. The output of the amplifier 20 is a force detection circuit 22.
The displacement detection signal from the differential transformer 9 is a displacement detection circuit.
18 sent to each, and as described above, the force detection circuit
The signal of 22 and the signal of the displacement detection circuit 18 are sent to the amplitude ratio / phase difference detector 19 and output as an amplitude ratio signal and a phase difference signal. These two signals (amplitude ratio and phase difference) are
As is well known, this is an amount expressing the viscoelasticity of a sample, and a desired complex elastic modulus is obtained by the above-mentioned calculation formula.

Although not particularly mentioned in the present embodiment, the force generator (coil 12, magnet 13) to the sample 1
Loss of force in the path leading up to, that is, inertial force due to the mass of the movable part (coil 12, coil holder 11, probe 4, core fixture 7, core 8, chuck 3) and viscous force for holding the movable part. The elastic effect (the elastic force of the probe 4 and the leaf spring 5 and the air resistance to the movable part) can be corrected as necessary.

(Embodiment 2) The present invention will be described in detail below with reference to FIG. 2 showing an embodiment. In the figure, reference numeral 1 denotes a sample. One end of the sample 1 is fixedly held by a sample holder and the other end is fixedly held by a sample chuck 3. The sample 1 is subjected to the stress described below in the thrust direction. The chuck 3 is fixed to the probe 4, the probe 4 is elastically fixed to the mechanism holder 40 by the two leaf springs 5 and 5, and the movement of the probe 4 is in a linear (one-dimensional) direction (thrust direction). ).

Further, one end of an L-shaped core fixture 7 is fixed to a part of the probe 4 between the two leaf springs 5 and 5, the core 8 is fixed to the other end, and the core 8 is fixed. One side of the core fixing tool 7 penetrates a hole (not shown) of the leaf spring 5 in a non-contact manner and is arranged in parallel with the probe 4.

A differential transformer 9 arranged around the core 8
And the core 8 constitute a detector for detecting the displacement of the probe in the thrust direction, and the position of the differential transformer 9 is determined by the mechanical part holder.
Determined by the micrometer 10 attached to 40. Further, a coil 12 is fixed to one end of the probe 4, and a magnet 13 fixed to the mechanism holding body 40 is arranged so as to surround the coil 12, and the coil 12 and the magnet 13 form a force generator 30. I am configuring.

On the other hand, a furnace 15 is arranged around the sample 1 for the purpose of setting the temperature environment of the sample 1. Furnace 15
The temperature can be changed according to a certain program in the heating furnace controller 17 by a conventional method. A sample temperature detector 16 measures the sample temperature with a thermocouple (not shown) arranged near the sample.

Reference numeral 21 in the figure denotes a sine wave generator, and the output (sine wave) of the sine wave generator 21 is adjusted in amplitude by the amplifier 20 and sent to the DC force generator 47 and the addition circuit 45. The DC force generator 47 generates a DC output 1.5 times the amplitude of the sine wave output sent from the amplifier 20 and sends it to the adder circuit 45. In the adder circuit 45, the output of the amplifier 48 and the output of the DC force generator 47 are added, an addition signal is sent to the coil 12, and the added force (sine wave AC force and DC The probe 4 generates a combined force). Also amplifier 20
Is output to the force detection circuit 22, and the sine wave force is calculated. The calculation of the sine wave force is performed by utilizing the fact that the relationship between the current generated by the amplifier 20 and the force generated by the force generator is related 1: 1 by a method not described in detail. The displacement detection signal from the differential transformer 9 and the core 8 is sent to the displacement detection circuit 18 and converted into a displacement signal. Force signal output from force detection circuit 19 and displacement detection circuit 43
The displacement signal which is the output of the sine wave is sent to the amplitude ratio / phase difference detector 44, respectively, and the amplitude ratio F ₀ / X of the sine wave AC force and the sine distortion is transmitted.
₀ and the phase difference τ are calculated.

For the amplitude ratio and the phase difference, the amount representing the dynamic viscoelasticity of the sample is obtained by an external computer (not shown) according to the following equations. E ^* = E ′ + iE ″ E ′ = | E ^* | cos δ E ″ = | E ^* | sin δ tan δ = E ″ / E ′ E ^* | = F ₀ / αX ₀ δ = ω ₀ τ On the other hand, the mechanical part is held The body 40 is supported by a strain detector moving mechanism, which moves the mechanism holder 40 to a ball screw.
The ball screw 32 is fixed to the housing base 14 by a bearing 32 and a bearing 38, and one end of the ball screw 32 is connected to a stepping motor 36 fixed to the housing base 14 via a drive belt 37.

In the operation of the apparatus according to the present embodiment, the output of the DC force generator 47 causes the coil 12 and the magnet 13 to generate a DC force 1.5 times the AC force amplitude applied later. Then, this DC force is transmitted to the sample 1 via the probe 4 and the chuck 3. At this time, the strain deformation generated in the sample is detected by the displacement detection circuit 18 by the functions of the core 8 and the differential transformer 9.

Next, this distortion signal is transmitted to the pulse motor drive circuit 50.
Is transmitted to the ball screw 32 by driving the stepping motor in the direction to remove this distortion deformation and transmitting the driving belt 37.
Is rotated to move the bearing 38 and the mechanical unit holder 40 to remove the strain deformation. Next, the sine wave generator 21 generates a sine wave signal of a desired frequency, the amplifier 20 appropriately adjusts the amplitude of the sine wave, and then the DC force generating circuit.
47 and the adder 45 add the output of the DC force generator 47 (1.5 times the amplitude of the sine wave). The adder circuit
The superimposed output signal of DC and sine wave of 45 is sent to the coil 12 to generate a sine wave force in cooperation with the magnet 13. The generated sine wave force passes through the probe 4 and the chuck 3,
A tensile stress is applied to the sample 1.

On the other hand, the strain generated in the sample 1 is transmitted to the core 8 as a displacement in the probe thrust direction through the chuck 3, the probe 4, and the core fixture 7, and detected as a displacement of the core 8 with respect to the differential transformer 9. It At this time, the displacement of the core 8 is a displacement of a part of the probe 4 fixed by the two leaf springs 5 and 5 whose both sides are deformed only in the probe thrust direction. Therefore, the displacement is limited only in the thrust direction. . The displacement detection signal from the differential transformer 9 is sent to the displacement detection circuit 18, and the signal of the force detection circuit 22 and the signal of the displacement detection circuit 18 are sent to the amplitude ratio / phase difference detector 19 and the amplitude ratio signal and position. It is output as a phase difference signal.
As is well known, these two signals (amplitude ratio and phase difference) are quantities that express the viscoelasticity of the sample, and a desired complex elastic modulus is obtained by the above-described calculation formula.

Although not particularly mentioned in the present embodiment, the loss of force in the path from the force generator 30 (coil 12, magnet 13) to the sample 1, that is, the movable part (coil 12, probe). 4, correction for inertial force due to the mass of the core fixture 7, core 8, chuck 3) and viscoelastic effect for holding the movable part (elastic force by the probe 4 and leaf springs 5, 5 and air resistance to the movable part) Can be done as needed.

[0025]

As described above, according to the present invention, in the dynamic viscoelasticity measuring device, a core fixing tool having one end fixed between the leaf springs of the probe fixed by two leaf springs is introduced. By making it possible to detect the displacement between the springs of the probe at another position, the following effects can be obtained.

When a sinusoidal stress is applied in the thrust direction of the probe, it is a portion that does not displace in the radial direction stress due to a slight axial misalignment when the probe is attached. Sample distortion detection with a transformer is performed accurately. The degree of freedom of the mounting position of the differential transformer core becomes high, and the fixed position of the differential transformer, which is easily affected by the environmental temperature, can be set at a position farther from the heating furnace.

[Brief description of drawings]

FIG. 1 is a sectional view with a partial block showing an embodiment of the present invention.

FIG. 2 is a sectional view with a partial block showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 sample 2 sample holding member 3 chuck 4 probe 5 leaf spring 7 core fixture 8 core 9 differential transformer 10 micrometer 11 coil holder 12 coil 13 magnet 14 housing 15 furnace 16 sample temperature detector 17 heating furnace controller 18 displacement Detection circuit 19 Amplitude / phase difference calculator 20 Amplifier 21 Sine wave generator 22 Force detection circuit 23 Sample holder 24 Sample holder 25 Chuck

Claims (1)

[Claims] 1. A housing, a probe, and a surface of the probe which are perpendicular to each other and are spaced apart from each other by a predetermined distance.
Two leaf springs that fix the points respectively and the other end is fixed to the housing to elastically fix the probe to the housing, and fixed to the housing at one end of the probe. A force generator that generates stress in the thrust direction of the probe, a chuck that is located at the other end of the probe and that holds the sample, and a displacement in the probe thrust direction that is fixed to the housing and that is generated by the generated force are detected. In the dynamic viscoelasticity measuring device having a differential transformer and a differential transformer core, a core attachment component having one end fixed to the probe and the other end fixed the differential transformer core is provided. The dynamic viscoelasticity measuring device, wherein a mounting portion of the core mounting component to the probe is located between the two leaf springs.