JP2614737B2 - Thermomechanical analyzer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a physical property analyzer for detecting expansion and contraction of a solid sample due to a temperature change.

Conventionally, a link mechanism has been used to measure the coefficient of thermal expansion or contraction of an arbitrary solid sample. That is, for example, by fixing one end of a rod-shaped sample housed in an electric furnace or the like, connecting the other end to a movable table, and supporting the movable table by a link mechanism, the above-described method is performed only in the direction in which expansion and contraction of the sample is to be detected. The movable table can be moved and the amount of movement caused by the temperature change is detected. However, the link mechanism needs to rotatably connect the connecting portions of the links with, for example, a pivot shaft or another appropriate shaft. For this reason, for example, even when a link mechanism is formed by rotatably connecting both ends of two parallel beams to the movable base and an appropriate fixed portion with a pivot axis, a total of eight pivot axes are required. As a result, not only an extremely large frictional resistance is generated, but also an eccentricity or the like due to a processing error of each bearing may further increase the frictional resistance. That is, it requires high-precision processing and assembly, which makes the apparatus expensive and has poor sensitivity. For example, a weight change of 200 mg causes only a displacement of about 1 mm. Therefore, the present invention eliminates such disadvantages,
An object of the present invention is to provide a thermomechanical analyzer which can be manufactured with extremely high precision and at a low cost.

According to the present invention, a movable table connected to one end of a sample and a fixed table arranged at an appropriate distance from the movable table are connected by a single main beam which is mounted on the movable table and both sides of the main beam. The torsion bands are arranged in parallel to each other, and both ends of the torsion band are connected to the movable table and the fixed table. Therefore, when one end of the sample is connected to the movable table, the movable table moves in parallel due to the expansion and contraction. By detecting the displacement of the movable table, the amount of expansion and contraction of the sample in a certain direction is accurately measured. . In addition, only the bearings are required at both ends of the main beam, and the two torsion bands do not require them. Therefore, there is no bearing friction and the friction is significantly increased due to the quality of machining accuracy. The fear is also eliminated. Therefore, according to the present invention, the device can be manufactured easily and inexpensively, and at the same time, the measurement accuracy is improved.

1 is a front view, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a sectional view taken along line BB of FIG.
It is the figure which expanded the cross section. In this way, for example, the columnar sample 1 is vertically arranged, the upper end thereof is brought into contact with the upper bottom of the support tube 2, the lower portion of the support tube 2 is fixed to the base 3, and the upper portion is placed in the heating furnace 4. Has been inserted. Further, the upper end of the vertically arranged detection rod 5 is brought into contact with the lower end of the sample 1 and the lower end of the detection rod 5 is connected to a connecting piece 7 by a horizontal shaft 6, and this connecting piece 7 is orthogonal to the shaft 6. It is connected to a movable base 9 by a horizontal shaft 8. Therefore, the movable table 9 can be inclined in an arbitrary direction in a vertical plane with respect to the vertical detection rod 5.
Further, a solid support 10 is arranged at an appropriate distance from the movable base 9 in the horizontal direction, and the fixed base is fixed to the base 3 with screws 11. The movable table 9 and the fixed table 10 are provided with a horizontal hole 12.13 in the same direction at the center thereof, so that the horizontal main beam 14 is loosely passed through the hole, and the pivot shafts 15 projecting from both sides of the beam are connected to the horizontal shaft 12. Movable table 9 and fixed table 10
The main beam 14 is held so that it can be freely tilted in a vertical plane by being supported by a pivot bearing 16 attached to the main beam. Further, one end of the beam 14 is
The weight 17 is screwed by protruding from
By adjusting the position, the sample can be pressed by applying a desired vertical force directed upward to the movable table 9. The movable base 9 and the fixed base 10 are provided with cutouts 18 on the upper and lower surfaces thereof, and press fittings 19 arranged on the edges of the cutouts are tightened with screws 20.0. In addition, the notch 18 and the edge of the metal fitting 19 are
It is located on the plane pq including the tip of 5.15. Torsion bands 21 and 22 parallel to the main beam 14 are arranged on the upper and lower sides of the main beam 14 so as to face the notch portion 18, and both ends of the torsion bands 21 and 22 are pressed by the fitting 19 and fastened by screws 20.
A core 24 of a differential transformer 23 is attached to the lower surface of the movable base 9, the transformer is connected to a power supply 25, and the output obtained from an output terminal 26 is detected, whereby the displacement of the movable base 9, that is, the sample 1 The amount of expansion and contraction is detected.
The torsion bands 21 and 22 have the width w shown in FIG.
Is a thin metal ribbon having a thickness of, for example, 0.4 mm and a thickness t of, for example, 0.05 mm.

In such an apparatus, when the sample 1 expands and contracts due to a change in the temperature of the furnace 4, the main beam 14 rotates about the tip of a pivot shaft 15 supported by the fixed base 10. Therefore, the core 24 of the differential transformer 23 moves, causing a change in the voltage of the output terminal 25. By detecting this voltage, the relationship between the temperature and the expansion and contraction can be measured, that is, thermomechanical analysis can be performed. . Further, in the above-mentioned apparatus, it is not necessary to provide a link on both sides to support the main beam 14 only at two places, and the two torsion bands make the main beam 14 extremely thin as described above. be able to. For this reason, the energy loss due to the inclination of the main beam can be reduced to a negligible extent, and high-sensitivity analysis can be performed. For example, when the band is used, only 20 mg is required. 1mm depending on the change
Could be generated. In addition, there are few parts that require high-precision processing, so that the apparatus can be manufactured at low cost, and there is little variation in characteristics due to processing accuracy. Therefore, uniform and high-precision characteristics can be easily obtained. effective.

[Brief description of the drawings]

1 is a front view, FIG. 2 is an AA cross-sectional view of FIG. 1, and FIG. 3 is an enlarged view of a BB cross section of FIG. In the figure, 1 is a sample, 4 is a heating furnace, 9
Is a movable table, 10 is a fixed table, 14 is a main beam, 15 is a pivot axis, 17 is a weight, 18 is a cutout, 19 is a holding bracket, 21 and
22 is a torsion band, 23 is a differential transformer, and 24 is a core.

Claims (1)

(57) [Claims] A sample for detecting expansion and contraction due to a temperature change is fixed at one end and the other end is supported by a movable table. The movable table is connected to a displacement detector, and the movable table and the fixed table are connected to these. The two main torsion bands are connected to each other in the direction of expansion and contraction of the sample by providing two torsion bands arranged in parallel with both sides of the main beam in the direction of expansion and contraction of the sample. Thermomechanical analyzer attached to the movable table and the fixed table at a position opposed to the beam attachment portion