JPH063302A - Thermogravimetric detector - Google Patents

Abstract

PURPOSE:To eliminate the influence of the elastic force of a signal fetching line an a thermogravimetric detector so as to reduce the occurrence of measurement errors and improve the measurement accuracy of the detector. CONSTITUTION:The detector is constituted of a balance rod 31 horizontally positioned and supported at its middle section, pivot bearings 51 and 52 provided on both sides of the rod 31, supporting rods 57 and 58 which are respectively supported by the bearings 51 and 52 in swingable states, extended to the middle section side of the rod 31 above the bearings 51 and 52, and support samples put in sample pates 63 and 64, and supporting wires 67 and 68 the one ends of which are respectively tied with one points on the rods 57 and 58, with the other ends being fixed to two fixing points on the detector side, and which respectively support the rods 57 and 58 from two directions. The wires 67 and 68 are constituted of a conductive material and connected to temperature sensors on the rods 57 and 58 sides. Signals from the sensors are fetched out through the wires 67 and 68.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermogravimetric detection device, and more particularly to a thermogravimetric detection device which eliminates an error that may occur due to the elasticity of a signal extraction line extracted from a support rod side.

[0002]

2. Description of the Related Art The present applicant has previously filed Japanese Patent Application No. 4-107557.
Proposed the weight detection device described in No. This weight detection device will be outlined based on FIG.

Reference numeral 1 in the figure is a balance bar arranged horizontally. The balance rod 1 is supported horizontally by a first pivot bearing 2 in a state where the balance rod 1 is horizontally arranged. The first pivot bearing 2 is composed of a pivot shaft 3 provided at an intermediate portion of the balance rod 1, and a bearing portion 4 attached to the base side to receive the pivot shaft 3.

At one end of the balance rod 1, there is provided a second pivot bearing 6 which supports the balance rod 1 and a support rod 9 described later so as to be swingable at one point. The second pivot bearing 6 is composed of a pivot shaft 7 provided at one end of the balance rod 1 and a bearing portion 8 provided at the base end of the support rod 9 and receiving the pivot shaft 7. The pivot shaft 7 and the bearing portion 8 are arranged such that their axes are aligned with the axial direction of the support rod 9, and support the force acting in an oblique direction from the support rod 9 at one point on the axis. There is.

Further, a supporting rod 9 is swingably attached to one end of the balance rod 1 via a second pivot bearing 6. The support rod 9 extends upward from the second pivot bearing 6 and is provided so as to be inclined toward the first pivot bearing 2 side. A weighing dish 10 is provided at the upper end of the support rod 9.

A support wire 12 is attached above the support rod 9. The support wire 12 has one end commonly held at a point above the support rod 9 and the other end fixed to the base side of the apparatus. The other end of the support wire 12 is fixed at two different fixing points and is horizontally arranged. That is, the wire locking point of the support rod 9 and the two fixing points on the base side are located in the same horizontal plane, and the wire 12 is arranged in the horizontal direction. In this state, only the horizontal component of the acting direction of the load by the object to be measured placed on the weighing dish 10 is supported. Further, the wire 12 does not have elasticity and has only flexibility. As a result, the support rod 9 is pulled from a plurality of directions and stably supported.

At the other end of the balance rod 1, a center-of-gravity adjusting screw 15 including an adjusting rod 16 and a weight 17 screwed to the adjusting rod 16 is provided.

Below the second pivot bearing 6 of the balance rod 1, a support 20, a magnet 23 attached to the lower end of the support 20, and a control coil 24 for restricting the movement of the magnet 23.
Is provided. On the other hand, a shutter 21 is attached to the tip portion of the adjusting rod 16, and a light source 25 and a light receiver 22 are attached on both sides of the shutter 21. The light receiver 22 has two light receiving elements 22a and 22b incorporated therein. In the light receiving elements 22a and 22b, the shutter 21
The light from the light source 25 is blocked by the shake of the light, and the amount of light received by each of the light receiving elements 22a and 22b changes, resulting in a difference in output value. This difference is input to the control circuit 26, and the control coil 24
To control. That is, when the sample is placed on the weighing pan 10, the balance bar 1 is tilted, and the shutter 21 is shaken together with the balance bar 1, and the light receiver 2
The output of 2 changes in the plus or minus direction and is input to the control circuit 26. The control circuit 26 controls the current flowing through the control coil 24 according to the input value so that the output of the photodetector 22 becomes zero.

Since the current flowing through the control coil 24 corresponds to the weight of the sample, it is converted into a digital signal by the A / D converter 28 through the gain adjusting circuit 27 as an external output, and is input to the CPU 29 for data processing.

In the weight detecting device constructed as described above, when the object to be measured is placed on the weighing pan 10, the load due to the object to be measured is passed through the support rod 9 to the second pivot bearing 6
Concentrate on the pivot axis 7. That is, the load acting on the second pivot bearing 6 via the support rod 9 is concentrated from the bearing portion 8 to the pivot shaft 7 that contacts the bearing portion 8 at one point. As a result, no matter where the object to be measured is placed on the weighing dish 10, the load caused by it is concentrated on the pivot shaft 7. As a result, the distance L from the shaft center of the first pivot bearing 2 to the point of action of the load on the second pivot bearing 6 always has a constant value regardless of the mounting position of the object to be measured, and the error at the four corners (special Wish 4
-107557 specification and FIGS. 2 and 3).

Further, in the second pivot bearing 6,
The acting direction of the load from the bearing portion 8 side to the pivot shaft 7 coincides with the axial center direction of the bearing 6, and the lateral force (direction orthogonal to the axial center of the bearing 6) hardly acts on the bearing 6,
The support rod 9 is stably supported by the second pivot bearing 6 and the wire 12, and the measurement accuracy is improved.

[0012]

By the way, in the weight detecting device, a temperature sensor may be attached to measure the temperature of the sample placed on the weighing dish 10. In this case, the temperature sensor is used. Attach to the part of the weighing pan 10,
The signal lead-out line is taken out from any part of the support rod 9. The signal take-out line is fixed to the take-out portion of the support rod 9 and the connecting portion on the device side.

However, since the signal take-out line has some elasticity, if the signal take-out line is fixed to the support rod 9 and the apparatus side, a slight force due to the signal take-out line acts on the support rod 9. Become. Then, there is a problem that the force acting on the support rod 9 causes an error in the measured value.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a thermogravimetric detection device capable of reducing the measurement error by eliminating the influence of the elasticity of the signal extraction line extracted from the support rod. And

[0015]

In order to solve the above-mentioned problems, the present invention is directed to a balance bar which is horizontally arranged and whose intermediate part is supported, a support means provided on the end side of the balance bar, and this support. Means that is swingably supported by the means, has a portion that is above the support means and that extends toward the intermediate support portion of the balance rod, and that supports the sample at the extension end side; and this support rod. A plurality of flexible support wire members, in which one end is commonly locked to one point and the other ends are fixed to different fixing points so that tensile forces are applied to one point of the support rod from a plurality of directions. And the flexible support wire member is constituted by a signal lead-out wire from the support rod side.

[0016]

By supporting the support rod by the signal take-out line constituting the flexible support line member, the influence of the elastic force of the signal take-out line is eliminated, the measurement error is reduced, and the measurement accuracy is improved.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a schematic perspective view showing a weight detecting device according to the present embodiment, FIG. 3 is a partial sectional view showing the weighing pan of FIG. 1, and FIG. 4 is a partial sectional view showing a portion of a supporting wire.

Reference numeral 31 in FIG. 1 denotes a balance bar arranged horizontally. The balance rod 31 is supported horizontally by a first pivot bearing 32 in a state where it is horizontally arranged. The first pivot bearing 32 includes a pivot shaft 33 located at the center of the balance rod 31 and extending on both sides (both sides in the direction orthogonal to the longitudinal direction of the balance rod 31) and a pivot shaft 33 attached to the device side. And a bearing portion 34 for receiving. Further, a balance bar control unit 36 is provided at the center of the balance bar 31. The balance rod control unit 36 is provided at the center of the balance rod 31 (first pivot bearing 32).
Position), and a balance rod drive unit 37 that returns to the zero position when the balance rod 31 rotates, and a rotation amount of the balance rod 31 that extends downward from the central portion of the balance rod 31. The rotation amount detection unit 38 is included.

The balance rod drive unit 37 is provided with an upper support column 41 extending upward from the central portion of the balance rod 31, and a support column 41 attached to the upper end of the support column 41 in the horizontal direction.
The magnet 42 that swings left and right according to the swinging of the
And a pair of control coils 43 which are attached to the apparatus side and in which both ends of the magnet 42 are respectively inserted and which appropriately push the magnet 42 from the left and right to swing the balance bar 31 to the horizontal state.

The rotation amount detecting section 38 is provided with a lower support column 45 which is provided so as to hang downward from the central portion of the balance rod 31, and is integrally attached to the lower end of the support column 45 and is moved to the left and right as the balance rod 31 swings. The shutter 46 includes a shutter 46 that swings and blocks light from a light source 47, which will be described later, and a pair of a light source 47 and a light receiver 48 that are respectively disposed on both sides of the shutter 46. In the light receiver 48, two light receiving elements 48A and 48B are incorporated in the left-right direction in parallel with each other as in the above-described conventional technique. The two light receiving elements 48A and 48B are respectively connected to a control circuit (not shown), and perform the same operation as the above-mentioned conventional technique.

At both ends of the balance rod 31, there are provided second pivot bearings 51 and 52 as supporting means for swingably supporting the balance rod 31 and support rods 57 and 58 described later at one point. The second pivot bearings 51 and 52 are the pivot shafts 5 provided at both ends of the balance rod 31, respectively.
3, 54 and the base ends of the support rods 57 and 58,
And a bearing portion (not shown) that receives each of the pivot shafts 53 and 54. The pivot shafts 53 and 54 and the bearing portion are arranged such that the shaft cores thereof are on the same line as the shaft center directions of the support rods 57 and 58, and support the force acting diagonally from the support rods 57 and 58 at one point on the shaft cores. It is supposed to do.

Further, support rods 57 and 58 are swingably attached to both ends of the balance rod 31 via the respective second pivot bearings 51 and 52. The support rods 57, 58 extend upward from the second pivot bearings 51, 52, respectively, and support arm portions 59, 60 are provided so as to be inclined toward the central portion of the balance rod 31, and the support arm portions. The upper horizontal arm portions 59A and 60A of the upper and lower horizontal arm portions 59A and 59A are composed of vertical support rod portions 61 and 62 which are vertically arranged in parallel with each other. The vertical support rod portions 61 and 62 are configured by a two-hole porcelain tube having two holes for passing two thermocouple wires 65A and 65B (66A and 66B), which will be described later, respectively.

Two trays 63 and 64 for mounting a standard sample and a sample for measurement, respectively, are provided at the tips of the vertical support rods 61 and 62. This saucer 6
Sample containers 63A and 64A respectively containing a standard sample and a measurement sample are mounted on the upper side surfaces of the units 3 and 64. As shown in FIG. 3, the temperature of the sample placed on the receiving pans 63, 64 is set on the lower side surface of the central part of the receiving pans 63, 64 (the lower side surface of the receiving pans 63, 64 located at the vertical support rod portions 61, 62). Temperature sensors 65 and 66 for measuring are provided respectively. Thermocouples are usually used as the temperature sensors 65 and 66. This temperature sensor (thermocouple) 65, 6
6 are two thermocouple wires 65A and 65B (66A,
66B) is welded to the lower side surfaces of the receiving pans 63 and 64. Two thermocouple wires 65A, 65B (66A, 66B) from the temperature sensors (thermocouples) 65, 66 are disposed below through the respective holes of the vertical support rod portions 61, 62, and support wires 67, 68 described later are provided. Connected with.

Support wires 67 and 68 as flexible support wire members are attached above the support arms 59 and 60. The support wires 67 and 68 are made of two conductive materials and are formed as signal output lines. One ends of the support wires 67 and 68 are commonly locked to upper points in the support arm portions 59 and 60, respectively, and the other ends are fixed to the device side. The other ends of the support wires 67 and 68 are fixed at two different fixing points, and are horizontally arranged as in the prior art. And this support wire 67,
68 is each connection terminal 72 of the relay terminals 72 and 73 attached to the upper horizontal arm portions 59A and 60A, respectively.
A, 72B, 73A, 73B, respectively. Further, the thermocouple wires 65A, 65B (66A, 66
B) is also each connection terminal 72A, 72B, 73A, 7
3B is connected. As a result, each connection terminal 72
A, 72B, 73A and 73B are support wires 67 and 68, respectively.
It is connected to the. The support wires 67 and 68 are fixed at the fixing points along the way and are connected to a temperature detecting device or the like. With this, the support rods 57 and 58 are pulled from a plurality of directions and stably supported while the temperature sensor 6 is being supported.
The signals from 5, 66 are taken out. The thermocouple wires 65A and 65B (66A and 66B) are made of a conductive material that does not have elasticity and has flexibility. Specifically, materials such as platinum-nickel alloy, carbon and phosphor bronze are used.

The thermogravimetric detection device having the above-described structure includes the second pivot bearings 51, 52 and the support wires 67,
When the standard sample and the sample to be measured are placed on the sample containers 63A and 64A of the upper receiving trays 63 and 64, which are stably supported by the support rods 57 and 58, the load due to the respective samples is increased. , 58 to concentrate on the pivot shafts 53, 54 of the second pivot bearings 51, 52, and achieve the same effect as the conventional weight detecting device.

Further, since the signals transmitted through the thermocouple wires 65A and 65B (66A and 66B) of the temperature sensors 65 and 66 are taken out to the outside by the support wires 67 and 68 as signal take-out lines, conventionally, it is special. It is possible to eliminate the influence of the elasticity of the signal lead-out lines from the side of the support rods 57 and 58 that have been provided, and it is possible to reliably eliminate measurement errors and improve measurement accuracy.

Although the signals of the temperature sensors 65 and 66 are taken as examples of the signals taken out from the supporting rods 57 and 58 in the above-mentioned embodiment, the present invention is not limited to this, and the electric signals of other electric elements or the like may be used. When taking it out, the same operation and effect as described above can be obtained.

Further, in the above embodiment, the supporting wire 6
Although the numbers 7 and 68 are relatively short, it is desirable to set the length as long as possible. By setting the support wires 67 and 68 to be long, the support wires 57 and 58 are supported by the support wires 67 and 68 when the support bars 57 and 58 move up and down.
It is possible to reliably eliminate the slight vertical component force that acts on, and improve the measurement accuracy.

The support wires 67 and 68 according to this embodiment can achieve the same actions and effects as in the above-mentioned embodiment even when used in the above-mentioned conventional weight detecting device.

Further, in the present embodiment, as the balance rod control unit 36, the balance rod drive unit 37 is provided above the balance rod 31 and the rotation amount detection unit 38 is provided below the balance rod 31, but the present invention is not limited to this. Instead, the balance rod drive unit 37 is provided below the balance rod 31, and the rotation amount detection unit 38 is provided above the balance rod 31, or both the balance rod drive unit 37 and the rotation amount detection unit 38 are provided above or below the balance rod 31. Good.

[0032]

As described in detail above, according to the thermogravimetric detector of the present invention, the flexible supporting wire member is constituted by the signal take-out line from the support rod side, so that the influence of the elastic force of the signal take-out line is exerted. Can be eliminated, the measurement error is reduced, and the measurement accuracy is improved.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a thermogravimetric detection device of the present invention.

FIG. 2 is a schematic perspective view showing a conventional weight detection device.

FIG. 3 is a partial cross-sectional view showing the weighing dish of FIG.

FIG. 4 is a partial cross-sectional view showing a portion of a support wire.

[Explanation of symbols]

31 ... Balance bar, 32 ... First pivot bearing, 51, 52 ...
Second pivot bearings, 57, 58 ... Support rods, 67, 68 ...
Support wire.

Claims (1)

[Claims] 1. A balance bar which is horizontally arranged and whose middle part is supported, a support means which is provided on an end side of the balance bar, and which is swingably supported by the support means and above the support means. And a support rod having a portion extending to the side of the intermediate support portion of the balance rod and supporting the sample on the extended end side, and one end is commonly locked to one point of this support rod and the other end is A plurality of flexible support wire members adapted to apply tensile forces from a plurality of directions to one point of the support rod by fixing them to different fixing points, wherein the flexible support wire member is on the support rod side. A thermogravimetric detection device comprising a signal extraction line from the.