JPH09105710A - Horizontal type thermobalance device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in weight detection precision of a sample when a sample position is shifted in the longitudinal direction of a sample supporting rod. SOLUTION: A balance rod 22 supported freely oscillatably via the first fulcrum 21 is provided with a position detecting means 33, which detects oscillation quantity of the balance rod 22, and a position correcting means 29, which restores the balance rod 22 to the horizontal condition on the basis of a detection signal from the position detecting means 33. In each end part of the balance rod 22, an auxiliary balance rod 24 is arranged freely oscillatably via the second fulcrum 23, and a sample supporting rod 25 is installed in each of the auxiliary balance rod 24, while in the intermediate part between both auxiliary balance rods 24, a connecting means 26 connecting the auxiliary balance rods 24 together without any restraint of their oscillation, is arranged. By means of the second fulcrum 23, only the weight of the sample works on the balance rod 22, so that generation of a weight detection error due to the moment based on a positional deviation of the sample can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal thermobalance device, and more particularly to a horizontal thermobalance device capable of highly sensitive and highly accurate measurement without causing a detection error due to a change in position of a sample. is there.

[0002]

2. Description of the Related Art Conventionally, as a horizontal type thermobalance device, for example, one disclosed in Japanese Utility Model Publication No. 61-42110 is known. As shown in FIG. 2, the horizontal thermobalance device described in Japanese Utility Model Publication No. 61-42110 supports a pair of sample holders having a sample holder 1 (1a, 1b) on one end of which a sample is placed. A rod 2 (2a, 2b) and a support means 3 which is provided substantially in the middle of these sample support rods 2 (2a, 2b) and supports them horizontally and swingably within a vertical plane; The sample holder 1 (1a, 1b) is inserted, and the heating furnace 4 for heating the sample placed on the sample holder 1 (1a, 1b) and the sample support rods 2 (2a, 2b) Of the sample holder 1 (1a,
1b) is provided at the end opposite to the side on which the sample support rods 1b) are provided, and a position detecting means 5 for detecting a deviation of each of the sample support rods 1 (1a, 1b) from the reference position in the swinging direction. ,
Position correction means 6 connected to each of the sample support rods 2 (2a, 2b) for correcting the deviation of each of the sample support rods 2 (2a, 2b) and returning to the reference position. There is.

The position detecting means 5 is attached to the sample support rod 1 and has a shutter 8 having a slit 7 having a predetermined width, a projector 9 for irradiating the slit 7 with light, and the projector 9 Against the shutter 8
And a light receiver 10 disposed on the opposite side of the sample support rod 1 by detecting a change in the amount of light projected through the slit 7 by the light receiver.
The amount of rocking, that is, the amount of deviation from the reference position is detected.

The position correcting means 6 is composed of an electromagnetic drive coil having a rotary shaft 11, is connected to the rotary shaft 11 via wires 12 and 13, and detects a signal from the position detecting means 5. The sample support rod 1 is returned to the reference position by controlling the electric current supplied to the electromagnetic drive coil on the basis of the electric current to control the rotational force applied to the rotating shaft 11. Based on the change of the above, the relative weight change of the sample placed on the sample holders 1a and 1b is detected.

In such a horizontal thermobalance apparatus, the reference sample 14 is placed on one of the sample holders 1a, and the test sample 15 is placed on the other sample holder 1b. When the sample holder 1 is inserted into the heating furnace 4 from the horizontal direction to heat each of the samples 14 and 15, and the weight of each of the samples 14 and 15 is changed by this heating,
The sample support rods 2a and 2b are respectively swung in the vertical plane due to the change in weight. The swing is restrained by controlling the current supplied to the position correcting means 6, and the current at that time is restrained. Based on the value, the relative weight change of the test sample 15 with respect to the reference sample 14 is detected.

In such a thermobalance apparatus, the sample support rod 2 is placed horizontally in the heating furnace 4 installed horizontally.
Since the component of the air convection in the heating furnace 4 along the swinging direction of the sample support rod 2 is small, the deterioration of the detection accuracy due to the air convection is suppressed. There is an advantage that is done.

[0007]

By the way, in the above-mentioned conventional horizontal thermobalance apparatus, each sample support rod 2a,
Sample holders 1a and 1b provided at one end of 2b
The samples 14 and 15 are placed on the sample, and the relative change in weight of the two samples 14 and 15 is detected based on the change in the moment acting on the sample support rods 2a and 2b due to the change in weight. However, the moment acting on the sample support rod 2 is the same as that of the sample 1 mounted on the sample holder 1.
4 (15) also changes depending on the position change in the length direction of the sample support rod 2. Then, for example, the sample 14
When (15) is melted by heating, the position of the center of gravity changes before and after melting.
The amount of rocking of the sample support rod 2 also changes due to the melting of (15), and as a result, there arises a problem that the accuracy of detecting the change in weight is reduced.

The present invention has been made in view of the above-mentioned conventional problems, and in the horizontal type thermobalance, even when the mounting position of the sample changes in the length direction of the sample support rod, The problem to be solved is to prevent the deterioration of the weight detection accuracy.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a balance bar which is horizontally installed and whose middle portion is swingably supported through a first fulcrum, and this balance bar. Position detecting means for detecting the amount of rocking of the balance, position correcting means for returning the balance bar to a horizontal state based on a detection signal from the position detecting means, and rocking motion at each end of the balance bar via a second fulcrum. A pair of auxiliary balance rods that are movably attached, a pair of sample support rods that are horizontally and integrally attached to the swing-side ends of these auxiliary balance rods, and an intermediate portion of both auxiliary balance rods It is characterized in that it comprises a connecting means for connecting without swinging the balance bar.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, reference numeral 20 is
1 shows a horizontal thermobalance device according to the present embodiment. The horizontal thermobalance device 20 includes a balance rod 22 that is horizontally installed and has an intermediate portion swingably supported via a first fulcrum 21. The second fulcrum 23 (2
3a, 23b) and a pair of auxiliary balance rods 24 (24a, 24b) that are swingably attached, and these auxiliary balance rods 24 (24a, 24b) are horizontally and integrally attached to the swing-side ends. A pair of sample support rods 25 (25a,
25b), and the two auxiliary balance bars 24 (24a, 24b)
The intermediate portion of the auxiliary balance bar 24 (24a, 24
b) and a connecting means 26 for connecting without restraining the swing.

[0011] Next, to explain these details, the balance bar 22 is formed in a cross shape, and the horizontal portion thereof has the second fulcrums 23 (23a, 23a) at both ends.
b) is provided, and the first fulcrum 2 is formed at an intermediate portion in the length direction of the load supporting portion 22a.
The portion extending vertically upward from the portion where 1 is provided is the position correcting portion 22b, and further, this position correcting portion 22b
A portion extending to the opposite side is a position detecting portion 22c.

Further, a magnet 27 is attached to the tip of the position correcting portion 22b so that both poles project on both sides in the swinging direction of the balance bar 22, and surround each pole of the magnet 27. Then 2
A coil 28, which is a set of individual pieces, is provided. The pair of coils 28 are wound in opposite windings and connected in series. The magnet 27 and the coil 28 constitute the position correcting means 29. By adjusting the current supplied to the coil 28 of the position correcting means 29, the load supporting portion 22a of the balance bar 22 is constantly operated. It is configured to be held in a horizontal state.

Further, a shutter 30 is formed by narrowing the tip of the position detecting section 22. The shutter 30 is sandwiched from the direction orthogonal to the swing direction of the balance bar 22 and the projector 31. A light receiver 32 is arranged, and these shutter 30, light projector 31, and
The position detector 33 is constituted by the light receiver 32. The light receiver 32 includes a pair of light receiving elements 34 that are spaced apart from each other by a distance smaller than the width of the shutter 30, and changes the degree of light shielding by the shutter 30 caused by the swing of the balance bar 22. This is detected as a change in the amount of light received by the light receiving element 34, and the swing amount of the balance bar 22 is detected based on this change in the amount of light received.

Each of the auxiliary balance bars 24 (24a, 24b)
Is a vertical portion 35 extending downward from the second fulcrum 23.
And a horizontal portion 36 that extends horizontally from the lower end of the vertical portion 35 toward the other vertical portion, and is formed in an L-shape. The sample support rod 25 is arranged below the first fulcrum 21 and is attached to each tip.
(25a, 25b) are attached so as to be horizontal and parallel to each other in a direction orthogonal to the swinging direction of the balance bar 22.

Each sample support rod 25 (25a, 25b)
Is attached through the auxiliary balance bar 24 through a socket 37 attached to the tip of the horizontal portion 33 of each of the auxiliary balance bars 24 (24a, 24b), and at each one end, A sample holder 38 (38a, 38b) on which a sample is placed is integrally attached, and a counterweight 39 for horizontally holding each sample support rod 25 (24a, 24b) is integrally attached to the other end. Has been.

In the present embodiment, the connecting means 26 connects the vertical portions 35 of the auxiliary balance bars 24 (24a, 24b) to each other, and the wire 40 directly below the first fulcrum 21. It is constituted by a pair of columnar fixing members 41 which are sandwiched and fixed at one point. Instead of the columnar fixing member 41, other means capable of gripping at one point, for example, the blades of a pair of wedge-shaped members may be opposed to each other, and may be gripped between them.

The wire 40 is parallel to the load support portion 22a of the balance rod 22, and both ends thereof are integrally fixed to the vertical portion 35 of each auxiliary balance rod 24 (24a, 24b). In the fixed portion, the load supporting portion 22a and the both vertical portions 35 form a parallel link by being bendable with respect to each of the auxiliary balance rods 24 (24a, 24b).

Further, in FIG. 1, reference numeral 42 indicates a heating furnace into which the sample holders 38 and the support rods 25 are inserted from the horizontal direction.

In the horizontal thermobalance device 20 according to the present embodiment having such a configuration, the reference sample 43 is placed on one sample holder 38a and the test sample 44 is placed on the other sample holder 38b. After placing, the sample holders 38 are inserted into the heating furnace 42 from the horizontal direction to heat both the samples 43 and 44.

In this case, when there is no change in weight of the sample, the weight of each sample 43, 44 is equal to that of each sample support rod 25.
(25a, 25b), socket 37, counterweight 39, and each auxiliary balance bar 24 (24a, 24b)
Together with the weight of each second fulcrum 23 (23a, 23b)
The load supporting portion 22a of the balance rod 22 is brought into a horizontal state by acting on each end of the balance rod 22 via the position adjusting means 29 and operating the position correcting means 29 based on the position detection signal from the position detecting means 33. Retained.

When the relative weight change occurs in each of the samples 43 and 44 with the progress of heating, each second fulcrum 23
The load acting on (23a, 23b) changes, whereby the balance bar 22 is swung around the first fulcrum 21, and the swing amount is detected by the position detection means 33 and the detection signal thereof is detected. The balance bar 22 is horizontally adjusted by adjusting the current supplied to both the position correcting means 29 based on the above, and based on the current value supplied to the position correcting means 29 at this time, A relative weight change of both samples 43, 44 is detected.

In the process of detecting the weight change, it is assumed that the samples 43 and 44 are displaced and the moment acting on the sample support rods 25 (25a and 25b) is changed. To be done. However, in the present embodiment, the load acts on both ends of the load supporting portion 22a of the balance rod 22 via the second fulcrum 23 (23a, 23b).
Each sample support rod 25 (25
a, 25b), the load acting on both ends of the load support portion 22a does not change even when the moment acting on the load support portion 22a changes. It does not change due to displacement. Therefore, the moment acting on the load supporting portion 22a is changed only by the pure weight change of both the samples 43 and 44, and the weight can be detected with high accuracy.

The shapes, sizes, etc. of the constituent members shown in the above embodiment are merely examples, and can be variously changed based on design requirements. For example, in the above example,
An example in which the sample support rod 25 is positioned below the balance rod 22 by suspending the auxiliary balance rod 24 below the balance rod 22 has been shown. However, these may be arranged above the balance rod 22. Is also possible.
In addition, although an example in which the connecting means 26 is configured by the flexible wire 40 and the pair of columnar fixing members 41 that holds the flexible wire 40 as the center is shown, a pair of connecting members 26 may be used instead of holding the pair of cylindrical fixing members. It may be held by a wedge-shaped holding member, or instead of using a wire, a rod-shaped rigid body is used, and both ends of the rigid body are used as auxiliary balance bars 24.
It is also possible to adopt a configuration in which the rotatably connected to.

[0024]

As described above, according to the horizontal type thermobalance apparatus of the present invention, the second fulcrum is provided on the balance rod that is swingably supported by the first support point to detect the weight of the sample. By supporting the sample via the sample, the moment generated by the sample on the balance bar is prevented from changing due to the position change of the sample, and the change of the moment acting on the balance bar is changed by the pure weight change of the sample. Highly accurate weight detection can be performed by relying only on

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a schematic configuration diagram of a horizontal thermobalance.

FIG. 2 is a schematic configuration diagram showing an example of a conventional horizontal thermobalance.

[Explanation of symbols]

 20 horizontal thermobalance 21 first fulcrum 22 balance bar 23 second fulcrum 24 auxiliary balance 25 sample support bar 26 connecting means 29 position correcting means 33 position detecting means

Claims (1)

[Claims] 1. The apparatus is installed horizontally and has a first intermediate portion.
The balance rod swingably supported via the fulcrum, the position detecting means for detecting the swing amount of the balance rod, and the position correcting means for returning the balance rod to the horizontal state based on the detection signal from the position detecting means. And second on each end of the balance bar.
A pair of auxiliary balance rods that are swingably attached via a fulcrum, a pair of sample support rods that are horizontally and integrally attached to the swing-side ends of these auxiliary balance rods, and an intermediate portion between the two auxiliary balance rods. A horizontal thermobalance device, characterized in that it comprises a connecting means for connecting the parts without restraining the swing of these auxiliary balance bars.