JPH05322814A - Thermobalance - Google Patents

Abstract

PURPOSE:To obtain a thermobalance which is free from the possibility of causing a decline in measurement accuracy due to the torsion of its auxiliary arm and so on and flexible rope of which can be made longer. CONSTITUTION:Auxiliary fulcra 23 and 24 are provided at both ends of the arm 22 of the title balance with a main fulcrum 21 at its central part. The upper end sections of a pair of auxiliary arms 25 and 26 which rise while they are respectively supported by the fulcra 23 and 24 are brought nearer to each other above the fulcrum 21. A pair of sample holders 27 and 28 respectively rising from the upper end sections of the arms 25 and 26 support a sample 29 and standard sample 30 in the same heating furnace 31. Rope supporting structures 41 having flexible ropes 42 and 43 which are stretched in the opposite directions from the upper ends of the arms 25 and 26 and tied with fixing sections 45 and 45 of a frame, etc., are provided for the arms 25 and 26 so as to control the rotation of the arms 25 and 26. While the arms 25 and 26 are always maintained in a balanced state by means of an automatic nullbalancing instrument 32, differential thermogravimetric analysis is performed based on the output of the instrument 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic balance type thermobalance, and more particularly to an improvement of a thermobalance which is made lightweight by using a flexible cable.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2 as a thermobalance, sub-fulcrums 3 and 4 are provided at both ends of an arm 2 of a balance having a main fulcrum 1 at the center, and the sub-fulcrums 3 and 4 are respectively provided. The pair of auxiliary arms 5 and 6 which are supported and risen are brought close to each other on the upper side of the main fulcrum of the balance, and the pair of sample holders 7 which are respectively risen from the adjacent upper ends of the auxiliary arms 5 and 6. , 8 and sample 9 and standard sample 10 in the same heating furnace 1
While being supported within 1, the auxiliary arms 5 and 6 are always kept in an equilibrium state by an automatic balancing device (not shown) such as a magnetic type, and differential thermogravimetric analysis is performed based on the output of the automatic balancing device. The thing of the structure is known.

Further, in the thermobalance having such a structure, since the upper ends of the auxiliary arms 5 and 6 are close to each other above the main fulcrum side of the balance, the center of gravity of the auxiliary arm itself and the sample. Since the auxiliary arms 5 and 6 always try to rotate due to the added weight, it is necessary to have a structure that prevents the rotation.

As a structure for preventing the rotation of the auxiliary arms 5 and 6 as described above, a structure in which the lower end sides of the auxiliary arms 5 and 6 are connected to each other by a link mechanism has been generally adopted. Due to the large weight, in recent years, as shown in FIG. 2, a cable support structure has been developed in which the flexible cables 13 and 14 connected to the fixed portion 12 such as a frame prevent the auxiliary arms 5 and 6 from rotating. There is.

[0005]

However, in the above-mentioned conventional structure, as shown in FIG.
Since the length of the balance is limited to half the distance between the auxiliary arms 5 and 6, the vertical component force ΔW (= Tsi
n θ: T becomes large in tension of the flexible rope. In order to reduce this vertical component force, it is necessary to lengthen the flexible cords 13 and 14.

Therefore, as a means for lengthening the flexible cords 13 and 14, conventionally, as shown in, for example, Japanese Patent Publication No. 62-50765, the fixing portion is arranged independently for each flexible cord, and each flexible cord is provided. It has been considered to separate the flexures vertically or horizontally so as not to interfere with each other.

However, with such a structure, the flexible cords are vertically or laterally displaced from each other, so that the binding position of the flexible cords with respect to the auxiliary arm is displaced, and as a result, the auxiliary arm is measured during measurement. There is a possibility that a twisting force may act on the core to reduce the measurement accuracy.

The present invention has been made to solve such a problem, and an object thereof is to make it possible to lengthen a flexible cable without a twisting force or the like acting on an auxiliary arm, thereby improving measurement accuracy. It is to provide a thermobalance that can be improved.

[0009]

In order to achieve the above-mentioned object, the present invention provides sub-fulcrums at both ends of an arm of a balance having a main fulcrum at its center, and the sub-fulcrums are respectively supported and rise up. The upper ends of a pair of auxiliary arms are brought closer to each other above the main fulcrum side of the balance, and the sample and the standard sample are placed in the same heating furnace on a pair of sample holders that rise from the upper ends of the adjacent auxiliary arms. On the other hand, while supporting the auxiliary arms, a rope support structure for supporting the auxiliary arms from the fixed side via flexible ropes is attached so as to keep the intervals between the upper ends of the auxiliary arms constant, and In the thermobalance for performing the differential thermogravimetric analysis on the basis of the output of the automatic balancer while keeping the auxiliary arm always in an equilibrium state by the automatic balancer, the flexible rope of the rope support structure is connected to the upper end of each auxiliary arm. Or It is made by extending in a direction away from each other toward the anti-principal fulcrum.

[0010]

According to the present invention, since the flexible ropes constituting the rope supporting structure for preventing the rotation of both auxiliary arms are stretched from the upper ends of the respective auxiliary arms in the directions away from each other, the flexible ropes are sufficiently It is possible to arrange them at the same height and on the same plane without mutual interference while ensuring a sufficient length.

Therefore, since the binding positions of the flexible rope to both auxiliary arms can be arranged at the same height and in the same plane, there is no fear that the auxiliary arm is affected by twisting or the like at the time of measurement, and it is highly accurate. It becomes possible to measure.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

As shown in FIG. 1, in the thermobalance of this embodiment, sub-fulcrums 23 and 24 are provided at both ends of an arm 22 of a balance having a main fulcrum 21 at the center. Each sub-fulcrum 2
Auxiliary arms 25 and 26 are respectively supported by 3 and 24, and the respective auxiliary arms 25 and 26 are tilted and the upper end side thereof is approached and raised. In addition, each auxiliary arm 2
A pair of sample holders 27 and 28 stand vertically at the upper ends of the samples 5 and 26, and a sample 29 and a standard sample 30 are placed in the same heating furnace, for example, an electric furnace 31, at the upper ends of the sample holders 27 and 28. Supported by.

Further, each auxiliary arm 25, 26 is provided with a rope support structure 41 for preventing their rotation. That is, the rope support structure 41 includes a pair of flexible ropes, one end of which is attached to the upper ends of the auxiliary arms 25 and 26, for example, the wires 42 and 43, and the other ends of the wires 42 and 43, respectively. A fixing portion 44 fixed to a fixing system such as a frame,
And 45. The wires 42 and 43 of the rope support structure 41 are connected to the auxiliary arms 25 and 26, respectively.
From the upper end toward the anti-main fulcrum 21 side in the direction away from each other.

On the other hand, below the main fulcrum 21 of the balance, there is provided an automatic balancing device 32 for constantly maintaining the auxiliary arms 25 and 26 in a balanced state. That is, in the automatic balancer 32, the hanging arm 33 that integrally hangs from the center of the arm 22 of the balance, the shutter 34 provided at the lower end of the hanging arm 33, and the light shielding amount change depending on the inclination angle of the shutter 34. Inclination angle detector 37 including a light source 35 and a light receiving element 36, an electromagnetic actuator 40 including a magnet 38 attached to the hanging arm 33 and a solenoid 39 attached to a frame (not shown) forming a fixed system. And a feedback circuit section (not shown) for holding the hanging arm 33 vertically by magnetically adjusting the operation of the actuator 40 according to the output signal from the inclination angle detecting section 37.

Although not shown, an adjusting magnetic force for maintaining the equilibrium state of each auxiliary arm 25, 26 by the feedback circuit unit is detected in association with the automatic balancing device 32, and thereby a differential thermogravimetric analysis is performed. Is provided.

In the thermobalance constructed as described above,
When the weight of the sample 29 in the electric furnace 31 changes during measurement, the sample holder 27 (28) and the auxiliary arm 25 (26) on the heavier side move downward, while the sample holder and the auxiliary on the smaller weight side move. Arm moves up,
The tilt of the arm 22 of the balance due to this is detected by the change in the light shielding amount between the light source 35 and the light receiving element 36 by the shutter 34 of the tilt angle detection unit 37, and further the feedback circuit according to the output signal from the tilt angle detection unit 37. The magnetic adjustment of the electromagnetic actuator 40 is performed in the section, which causes the hanging arm 33 to move.
Are held vertically, and at this time, the differential thermogravimetric analysis is performed by the calculation unit.

By the way, according to the present embodiment, the wires 42, 43 constituting the rope supporting structure 41 for preventing the rotation of the both auxiliary arms 25, 26 are separated from the upper ends of the respective auxiliary arms 25, 26 in the direction away from each other. Since it is stretched facing,
These wires 42 and 43 do not interfere with each other.
Therefore, since the wires 42 and 43 can be arranged at the same height and on the same plane while sufficiently ensuring the length thereof, the auxiliary arms 25 and 2 of the wires 42 and 43 can be arranged.
The binding positions for 6 can also be arranged at the same height and in the same plane.

That is, according to this embodiment, the wire 4
The connection positions of the auxiliary arms 25 and 26 with respect to the auxiliary arms 25 and 26 can be coaxially arranged, and unlike the conventional structure, there is no fear that the auxiliary arms 25 and 26 are affected by twisting or the like at the time of measurement, and high accuracy is achieved. It is possible to measure.

In the above embodiment, the automatic balancing device 32
Is provided below the balance, but the arrangement may be set at another position.

Further, in the above embodiment, the automatic balancing device 32
Although the inclination angle detection unit 37 has an optical configuration including the light source 35 and the light receiving element 36, the inclination angle detection unit 37 can be appropriately modified, for example, to have an electromagnetic configuration.

[0022]

As described above, according to the present invention, the flexible rope constituting the rope supporting structure for preventing the rotation of the both auxiliary arms is stretched from the upper ends of the respective auxiliary arms in the direction away from each other. Therefore, it is possible to arrange the same height and the same plane while ensuring a sufficient length by eliminating the mutual interference of the flexible cords, and therefore, there is no possibility that the auxiliary arm is affected by twisting or the like during measurement, The excellent effect that high-precision measurement is possible is exhibited.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a thermobalance according to the present invention.

FIG. 2 is a configuration diagram showing a conventional thermobalance.

FIG. 3 is an explanatory diagram showing an enlarged operation of a portion A in FIG.

[Explanation of symbols]

21 Main fulcrum 22 Arm of balance
23, 24 Sub-fulcrum 25, 26 Auxiliary arm 27, 28 Sample holder
29 sample 30 standard sample 31 electric furnace (heating furnace)
32 automatic balancer 41 rope support structure 42, 43 flexible rope
44, 45 Fixed part

Claims (1)

[Claims] 1. A sub-fulcrum is provided at each end of an arm of a balance having a main fulcrum at its center, and upper ends of a pair of auxiliary arms which are respectively supported by the respective sub-fulcrums and stand up are on the main fulcrum side of the balance. The sample and the standard sample are supported in the same heating furnace by a pair of sample holders that are brought close to each other and rise from the respective upper ends of the adjacent auxiliary arms, while the rotation of the both auxiliary arms is restricted and their upper ends are supported. In order to keep the interval between the parts constant, a rope supporting structure for supporting the both auxiliary arms from the fixed side via a flexible rope is attached, and the auxiliary arms are always kept in an equilibrium state by an automatic balancing device. In a thermobalance for performing a differential thermogravimetric analysis based on the output of an automatic balancer, a flexible rope of the rope supporting structure is extended from the upper ends of the auxiliary arms in directions away from each other toward the anti-main fulcrum side. Was it A thermobalance.