JPH0361842A - thermomechanical analyzer - Google Patents

Abstract

PURPOSE:To enhance operability by making it possible to move and stop a detecting rod in the axial direction with coils and a magnet in a thermal- machine analyzer wherein the detecting rod and a means for energizing the detecting rod upward are provided, one end of the rod is brought into contact with a sample, and a focus coil which reacts with a permanent magnet to each other and differential transformer cores are attached to the detecting rod. CONSTITUTION:The lower end of a detecting rod 1 constituting a thermal- machine analyzer is in contact with a sample M. The upper end part of the rod 1 is connected to a fixing block 10 through a spring 2. A focus coil 3 and a permanent magnet 4 surrounding the coil 3 are provided for the detecting rod 1. A current is made to flow through the coil 3. Compressing and tensile loads are applied to the sample through the detecting rod 1 by the mutual actions of the coil and the magnet. A differential transformer coil 5 and a differential transformer core 6 are provided for the detecting rod 1. The length of the sample M is detected based on the movement of the core 6. The sample M is provided at the bottom of a sample supporting pipe 7. The sample M is heated by the electric furnace 8. In this way, the appropriate loads are applied on the sample M only when the current is made to flow through the coil 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermomechanical analysis device that heats a sample, applies an appropriate load, and measures the effects associated with thermal changes in the sample.

[Conventional technology]

In a thermomechanical analyzer, a detection rod is brought into direct contact with a sample to heat it and measure changes in dimensions of the sample.

As a support system for the detection rod of such a thermomechanical analyzer, there is one that utilizes a balance mechanism in which the detection rod is attached to one end of the beam and a counterweight is attached to the other end. In thermomechanical analysis equipment using this balance mechanism, the balance is balanced with a detection rod, differential transformer core, and force coil attached, and samples are changed and installed by moving the sample support tube up and down. .

[Problem to be solved by the invention]

In thermomechanical analyzers using a balance system, the sample is set in a state where the balance is in equilibrium, so when changing the sample, the sample support tube is moved manually or by a motor. It is also possible to change the sample by moving the detection rod using the load generated by applying a current to the force coil, but even if you try to move the detection rod using the force coil, the detection rod will stop at an appropriate position. It is also difficult to adjust the movement speed.

This invention has been made to solve this problem.

[Means to solve the problem]

That is, in a thermomechanical analysis device having a detection rod having one end in contact with a sample and having a force coil and a differential transformer core attached that interact with a permanent magnet, and a biasing means for biasing the detection rod upward, It is characterized in that the detection rod is freely moved in the axial direction and stopped by the action of the force coil and the permanent magnet.

[For production]

When changing the sample, first, no current is applied to the force coil and the load is set to zero. The length of the spring at this time is 0. Then, a current is applied to the force coil so that an upward force of ΔF is generated. If the length of the spring at this time is , then ΔF is '-k (Ll L
o) By increasing or decreasing the force coil load ΔF by an appropriate value, the detection rod can be stopped at an appropriate position. In this way, after changing the sample, by returning ΔF to zero again, it is possible to restore the state in which the sample and the detection rod are in contact with each other under no load.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an embodiment of a thermomechanical analysis device according to the present invention. In this figure, 1 is a detection rod whose lower end is brought into contact with the sample M. Reference numeral 2 denotes a spring, one of which is connected to the upper end of the detection rod 1 and the other to the fixed block 10. 3 is a force coil attached to the detection rod 1; 4 is a permanent magnet; a current is passed through the force coil 3, and the interaction between these causes a compressive or tensile load to be applied to the sample M via the detection rod 1; It has become.

5 is a differential transformer coil connected to the detection rod 1; 6 is a differential transformer core; the movement of the differential transformer core 6 detects changes in the length of the sample M;

7 is a sample support tube with a sample M installed at the bottom, and an electric furnace 8
Heat it up.

As is clear from the above explanation, the detection rod 1, force coil 3, and differential transformer core 6 are integrally suspended from the spring 2, but these loads are normally applied to the sample M when the sample is not heated. Keep it in an equilibrium state so that it doesn't overwhelm you. As described above, when a current is passed through the force coil 3, an appropriate load is applied to the sample M due to the interaction between the force coil 3 and the permanent magnet 4. In addition, during thermal analysis, the sample M is heated in the electric furnace 8 and the sample length changes, but this amount of change is immediately detected as a change in the electrical signals of the differential transformer core 6 and the differential transformer coil 5, and the change Physical quantities such as the expansion coefficient of the sample M can be known from the quantity. Furthermore, numeral 9 is a micrometer which is used to measure the sample length and to manually move the detection rod 1 via the block 10.

The configuration of the thermomechanical analyzer according to the present invention is as described above, and next, the operation for changing the sample will be explained.

FIGS. 2 and 3 are simplified vertical cross-sectional views of the thermomechanical analysis apparatus according to the present invention, showing the state when changing samples. Second
In the figure, no current is applied to the force coil 3 and the load is zero, and the length of the spring 2 at this time is Lo.

Next, in FIG. 3, a current is applied to the force coil 3 so that an upward force ΔF is generated. Let the length of the spring 2 at this time be Ll. Therefore, if the spring constant is k, ΔF=k(Lt Lo), and by increasing the load ΔF of the force coil 3 by an appropriate value, the detection rod 1 can be stopped at an appropriate position. By returning ΔF to zero after changing the sample in this manner, it is possible to return to the state in which the sample M and the detection rod 1 are in contact with each other under no load as shown in FIG. 2.

One embodiment of the present invention is as described above, and the spring 2
Although a coil spring is used, the biasing means is not limited to a coil spring, and may be an air spring, a plate spring, or the like. In addition, the mounting position is not limited to the upper end, but also from the middle of the detection rod 1 to the fixed block 1.
It may be fixed at 0.

〔Effect of the invention〕

Since the thermomechanical analyzer according to the present invention has the configuration described in detail above, the force coil, which originally had the role of adding an appropriate load to the sample when analyzing the sample, is used for changing the sample and for setting the sample. It can be used. Therefore, it is possible to speed up sample changes, installation, etc., and to dramatically improve operability.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the thermomechanical analyzer according to the present invention, and FIGS. 2 and 3 are simplified longitudinal cross-sectional views of the thermomechanical analyzer according to the present invention, showing the state at the time of sample change. FIG. 1- Detection rod 2- Spring 3- Force coil 4- Permanent magnet 5- Differential transformer coil 6- Differential transformer core 7- Sample support tube 8- Heating furnace 9- Micrometer 10- Fixed block

Claims (1)

[Claims] (1) In a thermomechanical analysis device having a detection rod having one end in contact with a sample and having a force coil and a differential transformer core attached that interact with a permanent magnet, and a biasing means for biasing the detection rod upward. . A thermomechanical analysis device, characterized in that the detection rod is freely moved in the axial direction and stopped by the action of the force coil and the permanent magnet.