JP2008082861A - Thermal analysis device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal analysis device having a balance beam replaceable easily with safety. <P>SOLUTION: The thermal analysis device includes: the balance beam 23b composed of a first beam 24b and a second beam 25b connected to each other; a fulcrum 22b supporting the first beam 24b inclinably rockably; and a housing 18 housing the fulcrum 22b and the first beam 24b and having an opening 19. The second beam 25b is inserted into the housing 18 through the opening 19 to be connected to the first beam 24b, extends externally outside the housing 18, and supports a sample S at the end on the connection side and that on the opposite side. The housing 18 has a transparent cover 17 disposed on the upper side thereof enabling the visual recognition of the connection portion of the first beam 24b and the second beam 25b. The second beam 25b is detachable without removing the upper side plate of the housing 18. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermal analysis apparatus configured to perform thermal analysis measurement in a state where a part of a balance beam is stored in a housing.

  TG (Thermogravimetry: Thermogravimetry) apparatus and TG-DTA (Thermogravimetry-Differential Thermal Analysis) apparatus are known as thermal analyzers using a balance beam. The TG device is a device that measures a change in weight of a sample with respect to a temperature change or a lapse of time. The TG-DTA device is a device having a function of the DTA device in addition to the function of the TG device. The DTA device measures the temperature difference that occurs between the thermally stable reference material and the sample at the same time and reacts to the heat of the sample. A device to know.

  In a thermal analysis apparatus using a balance beam, the portion of the balance beam opposite to the sample support side is generally stored in a housing together with auxiliary equipment such as a fulcrum, an inclination detection mechanism, and a beam drive mechanism. This is because the balance mechanism is a very precise mechanism, and the delicate movement of the balance beam affects the measurement, so that the balance beam needs to be isolated from the external atmosphere as much as possible.

  In addition, the balance beam is often divided into two parts, a part that supports the sample and a part that is supported by a fulcrum, and is used as one balance beam by connecting both parts to each other (for example, patents). Reference 1). In order to divide the balance beam in this way, it is necessary to replace the part supporting the sample according to the sample, or to replace the part with a new one when the part supporting the sample is damaged or worn out. Because.

JP-A-8-184545 (page 4, FIG. 1)

  In a thermal analyzer having a structure in which a part of a balance beam is stored in a housing, when a split-structure balance beam is used, generally, two beam elements are connected to each other inside the housing. Then, the operation of connecting or separating the two beam elements is performed by removing the upper lid of the housing from the housing base and visually cutting the connecting portion of the two beam elements, and then connecting or separating the two beam elements. Had gone.

  However, the operation of attaching and detaching the top cover of the housing every time the sample support portion of the balance beam is attached and detached is very troublesome. In addition, there is a risk of damaging the inside of the upper lid or the housing base during the attaching / detaching operation of the upper lid. In particular, when the housing is formed in an airtight structure, the airtight structure may be damaged by the attaching / detaching operation of the upper lid. Moreover, there is a possibility that the balance mechanism and its attached devices may be damaged when the upper lid is attached or detached.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a thermal analyzer capable of easily and safely exchanging a balance beam.

  A first thermal analysis apparatus according to the present invention includes a balance beam formed by connecting a first beam and a second beam, a fulcrum that supports the first beam so as to be tilted and swingable, the fulcrum, and the first A housing for storing a beam and having an opening, wherein the second beam is inserted into the housing through the opening and connected to the first beam and extends to the outside of the housing. The housing is provided with a transparent portion that supports a sample at an end opposite to the end and uses a connection portion between the first beam and the second beam as a visible region.

  According to this thermal analysis apparatus, the first beam and the second beam can be attached / detached while observing the balance beam through the transparent part. There is no need to remove it one by one. For this reason, the attaching / detaching operation of the second beam is very simple, and the internal structure of the housing and the balance mechanism are not damaged.

  Next, in the first thermal analysis apparatus, one of the first beam and the second beam has a plug to be inserted, and the other of them has a socket for receiving the insertion, and the first beam and the second beam The beams are preferably connected to each other by fitting the plug and socket. With this configuration, the first beam and the second beam can be easily and reliably connected. In the case of the structure in which the first beam and the second beam are attached / detached without removing the upper lid as in the present invention, a complicated attaching / detaching structure cannot be adopted. Therefore, the plug / socket structure having the above described insertion / removal structure is suitable for the present invention.

  Next, in the first thermal analyzer, the plug or socket included in the first beam has a mark in a visible region of the transparent portion, and the socket or plug included in the second beam is the first beam. It is desirable to have a mark corresponding to one beam mark. When performing thermal analysis measurement on a sample, it is necessary to measure the temperature of the sample. In order to respond to this, a thermocouple wire is inserted inside the second beam, a terminal connected to the thermocouple wire is provided inside the plug or socket, and the terminals are connected when the plug and socket are fitted together. Thus, a structure in which the thermocouple is electrically connected may be employed. When such a structure is adopted, the plug and the socket must be fitted in a state where the relative positions of both are correct. In this regard, according to the aspect of the present invention in which a mark is provided on the plug and the socket, the operator aligns the mark on the first beam side and the mark on the second beam side, so that the first beam and the second beam are aligned. The beam can always be connected in the correct positional relationship.

  Next, in the first thermal analysis apparatus, the housing has a box-shaped housing base whose upper surface is opened, and a transparent cover fixed to the upper surface of the housing base, and the transparent portion is the transparent cover. It is desirable to be formed by. According to this configuration, a desired transparent portion can be formed only by a simple operation of fixing the transparent member to the housing base by screwing or the like. For example, the housing base can be made of aluminum, and the transparent cover can be made of acrylic resin.

Next, the second thermal analyzer according to the present invention is:
(1) Sample temperature control means for surrounding the sample and controlling the temperature of the sample;
(2) a balance unit that moves between a position coupled to the sample temperature control means and a position away from the sample temperature control means;
(3) The balance unit is
(A) a balance beam formed by connecting the first beam and the second beam;
(B) a fulcrum supporting the first beam so as to be capable of tilting and swinging;
(C) a housing housing the fulcrum and the first beam and having an opening;
(D) The second beam is inserted into the housing through the opening, is connected to the first beam, extends to the outside of the housing, and is at the end opposite to the end on the connection side. Support
(E) a transparent portion having a connection portion between the first beam and the second beam as a visible region is provided in the housing;
(4) The portion of the second beam that extends outside the housing is disposed inside the sample temperature control means when the housing is coupled to the sample temperature control means.

  This second thermal analyzer is a thermal analyzer having a sample temperature control means in addition to the balance unit. The sample temperature control means includes, for example, a protective tube that accommodates the sample and a heater provided around the outer periphery of the protective tube. The balance unit moves between a position coupled to the sample temperature control means and a position away from the position. The reason for adopting such a moving structure is to bring the sample support portion of the balance beam out of the sample temperature control means when exchanging the sample supported by the balance beam.

  In order to move the balance unit including the balance beam, it is necessary to place the balance unit on an appropriate moving mechanism. When the balance unit is placed on the movement mechanism, if any force is applied to the balance unit, the movement mechanism may be damaged. When attaching / detaching the second beam of the balance beam to / from the first beam, if the upper cover of the housing of the balance unit is attached / detached to / from the housing base body as in the prior art, the attaching / detaching operation is performed. In the meantime, an external force may be applied to the moving mechanism to cause damage to the moving mechanism. On the other hand, according to the present invention in which the housing is provided with the transparent portion, it is not necessary to attach or detach the upper cover of the housing when attaching or detaching the second beam, so that the moving mechanism is not damaged.

  According to the present invention, the first beam and the second beam can be attached / detached while observing the balance beam through the transparent portion. Therefore, the upper cover of the housing is removed one by one when the second beam is exchanged or attached. There is no need. For this reason, the attaching / detaching operation of the second beam is very simple, and the internal structure of the housing and the balance mechanism are not damaged.

  Hereinafter, a thermal analyzer according to the present invention will be described based on embodiments. Of course, the present invention is not limited to this embodiment. In the following description, the drawings are referred to. In the drawings, the components may be shown in different ratios from the actual ones in order to show the characteristic parts in an easy-to-understand manner.

  FIG. 1 shows the overall structure of a TG-DTA apparatus which is an example of a thermal analysis apparatus according to the present invention. In FIG. 1, the thermal analysis apparatus 1 includes a main body cover 2, three covers 3 a, 3 b, 3 c attached on the main body cover 2, and front surfaces of the covers 3 a to 3 c, and the main body cover 2. And an operation unit cover 4 attached to the top of the. A device for performing thermal analysis measurement is stored in an internal space surrounded by the covers 2, 3 a to 3 c, 4. Each cover is made of metal, synthetic resin, or the like. Each cover is connected by an arbitrary connection method such as screwing, engagement between the engaging portion and the engaged portion, or the like.

  FIG. 2 shows a state in which the upper covers 3a, 3b, 3c and the operation unit cover 4 are removed from the thermal analyzer 1 shown in FIG. FIG. 3 shows a front cross-sectional structure of the thermal analysis device 1. FIG. 4 shows a planar cross-sectional structure of the thermal analysis apparatus 1. In FIG. 2, a balance unit 6, a sample moving device 7, and a sample temperature control device 8 are provided inside the cover 2.

  As shown in FIGS. 3 and 4, the sample temperature control device 8 includes a protective tube 14, a heater 12, a cooling fin 9, and a blower duct 10. The heater 12 functions as a heating device that heats the sample S and the reference material R. The cooling fin 9 and the air duct 10 act as a cooling device for cooling the sample temperature control device 8. The cooling fin 9 also functions to cool the sample S and the like. The heater 12 is formed by, for example, winding a heater wire around a cylindrical heater bobbin. A temperature control circuit 13 is connected to the heater wire of the heater 12 as shown in FIG. The temperature control circuit 13 controls the current supplied to the heater wire of the heater 12 in accordance with a temperature control program stored in itself or a temperature control program stored in a host computer (not shown).

  The protective tube 14 is formed in a cylindrical shape from ceramic, for example, and is provided inside the heater 12. The protective tube 14 mainly protects the heater 12 from the gas generated from the sample S. The right side portion of the protective tube 14 is a large diameter cylindrical portion, and the left side portion thereof is a small diameter cylindrical portion. A large-diameter portion of the protective tube 14 is accommodated in the heating area inside the heater 12. The protective tube 14 extends to the outside on the right side of the heater 12, and the cooling fin 9 is provided on the outer periphery of the protective tube 14 in the extended portion. The right end surface of the protective tube 14 is an opening.

  The balance unit 6 has a housing 18 made of metal or synthetic resin and having a plate-shaped transparent cover 17 fixed to the upper surface of a box-shaped housing base 16 by screws or other fixing methods. The housing base 16 is made of aluminum, for example. The transparent cover 17 is formed of, for example, a translucent synthetic resin, such as an acrylic resin. An opening 19 for inserting the balance beam is provided in the approximate center of the left side plate of the housing base 16. A portion other than the opening 19 of the housing 18 has an airtight structure. The reason why the upper cover of the housing 18 is formed by the transparent cover 17 will be described in detail later. However, it is possible to perform the exchange operation of the balance beam by the measurer at the opening 19 without removing the upper cover of the housing 18. It is to do.

  FIG. 5 shows a planar structure of the balance unit 6. FIG. 6 shows a side structure of a balance mechanism provided inside the balance unit 6 and an electric circuit associated with the balance mechanism. In FIG. 6, one of the two balance mechanisms on the back side is originally hidden behind the near-side balance mechanism, but in FIG. 6, these balance mechanisms are drawn side by side for convenience. Yes.

  In FIG. 5, two balance mechanisms, a reference-side balance mechanism 21a and a sample-side balance mechanism 21b, are provided inside the housing 18. These balance mechanisms 21a and 21b have balance beams 23a and 23b supported so as to be tilted and swingable by torsion wires 22a and 22b (hereinafter simply referred to as fulcrums 22a and 22b) that function as fulcrums. Yes. These balance beams 23a and 23b are formed by connecting the second beams 25a and 25b to the first beams 24a and 24b supported by the torsion wires 22a and 22b.

  L-shaped socket portions 26a and 26b are provided at the left ends of the first beams 24a and 24b, plug portions 27a and 27b are provided at the right ends of the second beams 25a and 25b, and the plug portions 27a and 27b are supplementary views. As shown in (a) and (b), the first beams 24a, 24b and the second beams 25a, 25b are connected by fitting into the socket portions 26a, 26b to form the balance beams 23a, 23b. In the present embodiment, the sample-side balance beam 23b constitutes a sample support means for supporting the sample S. The marks 29a and 29b in the supplementary figures (a) and (b) are confirmation marks for preventing the mounting angles of the plug portions 27a and 27b from the socket portions 26a and 26b from being mistaken.

  Sample dishes (a heat sensitive plate in the case of TG-DTA, hereinafter referred to as a heat sensitive plate) 30a, 30b are fixed to the tips of the second beams 25a, 25b. A thermally stable reference material R is placed on the reference side thermal plate 30a, and a sample S to be measured is placed on the sample side thermal plate 30b. It is assumed that both the reference substance R and the sample S are placed on the heat sensitive plates 30a and 30b in a state of being placed in a container having a predetermined shape. Although not shown in detail, a plurality of thermocouple wires constituting the thermocouple are fixed to the bottom surfaces of the heat sensitive plates 30a and 30b by welding or the like, and these thermocouple wires are disposed inside the second beams 25a and 25b. It extends to the plug portions 27a and 27b and serves as a terminal. On the other hand, a DTA measurement circuit 31 is connected to the socket portions 26a and 26b. Input / output lines extending from the DTA measurement circuit 31 extend to the socket portions 26a and 26b and serve as terminals. The DTA measurement circuit 31 is provided at an appropriate position in the space surrounded by the cover 2 in FIG.

  By inserting the plug portions 27a and 27b into the socket portions 26a and 26b, their internal terminals are in electrical contact with each other, and the thermocouple wires extending from the heat sensitive plates 30a and 30b are connected to the input / output ports of the DTA measurement circuit 31. Is done. The DTA measurement circuit 31 detects a change over time in the temperature difference between the sample-side thermal plate 30b and the reference-side thermal plate 30a. The thermal change generated in the sample S can be known based on the detected temperature difference change. In addition, the structure disclosed by Unexamined-Japanese-Patent No. 8-184545 can be employ | adopted for the connection structure of the plug parts 27a and 27b and socket part 26a, 26b.

  The operation of connecting or separating the first beams 24a, 24b and the second beams 25a, 25b of the balance beams 23a, 23b by attaching and detaching the plug portions 27a, 27b to the socket portions 26a, 26b is mainly performed. In addition, this is an operation performed for exchanging the second beams 25a and 25b. When the measurer performs this replacement work, the measurer must perform the work while visually checking the plug portion and the socket portion. In the present embodiment, since the upper lid 17 of the housing 18 is formed of a transparent member, the measurer replaces the second beams 25a and 25b while visually confirming the plug portion and the socket portion without removing the upper lid 17 from the housing base body 16. Can work and is very convenient.

  In FIG. 6, the 1st electromagnetic coil 33a is attached to the part close | similar to the fulcrum 22a of the 1st beam 24a of the reference | standard side balance beam 23a. A magnet 34a is provided through the first electromagnetic coil 33a. A second electromagnetic coil 33b and a third electromagnetic coil 33c are attached to a portion of the sample-side balance beam 23b near the fulcrum 22b of the first beam 24b. The second electromagnetic coil 33b and the third electromagnetic coil 33c are wound one by one on one side of one coil bobbin, or are wound around one coil bobbin. A magnet 34b is provided through the second electromagnetic coil 33b and the third electromagnetic coil 33c. The magnets 34a and 34b are fixed to the housing base 16 in FIG.

  In FIG. 6, the first electromagnetic coil 33a and the magnet 34a act as a beam driving device 28a that tilts and moves the balance beam 23a around the fulcrum 22a. The second electromagnetic coil 33b, the third electromagnetic coil 33c, and the magnet 34b act as a beam driving device 28b that tilts and moves the balance beam 23b around the fulcrum 22b. Balance weights 35a and 35b are fixed to the middle of each of the first beams 24a and 24b in a variable manner by screws. By appropriately adjusting the positions of the balance weights 35a and 35b on the beam, the balance beams 23a and 23b can be set to an initial equilibrium state.

  Tilt detection mechanisms 37a and 37b are provided at the right ends of the first beams 24a and 24b. The tilt detection mechanisms 37a and 37b include slits 38a and 38b formed at the rear ends of the first beams 24a and 24b, light sources 39a and 39b disposed on one side of the slits 38a and 38b, and slits 38a and 38b. It has the light receiving elements 40a and 40b arranged on the other side. The light sources 39a and 39b can be configured by, for example, LEDs (Light Emitting Diodes). The light receiving elements 40a and 40b can be constituted by photodiodes, for example.

  A feedback control circuit 42 is provided between the tilt detection mechanisms 37a and 37b and the beam driving mechanisms 28a and 28b. The feedback control circuit 42 includes a balance beam 23a. Control for maintaining 23b in a horizontal state is performed. In addition, a TG measurement circuit 43 is connected to a current-carrying downstream terminal of the third electromagnetic coil 33c in the beam drive device 28b on the sample side. The TG measurement circuit 43 calculates the weight change generated in the sample S based on the value of the current flowing through the third electromagnetic coil 33c. The feedback control circuit 42 and the TG measurement circuit 43 are provided at appropriate positions in the space surrounded by the cover 2 in FIG.

  The feedback control circuit 42 and the TG measurement circuit 43 have the same circuit configuration as that disclosed in JP-A-8-292142. Hereinafter, these circuits will be briefly described. The feedback control circuit 42 includes a reference material side control circuit 44 connected to the output terminal of the light receiving element 40a in the reference side balance mechanism 21a. The reference material control circuit 44 is configured by using, for example, a PID (Proportional Integral Derivative) circuit, the output of which is taken out in parallel in two directions, and one output signal is passed through the amplifier circuit 45a. It is transmitted to the input terminal of the first electromagnetic coil 33a in the beam driving device 28a on the reference side balance mechanism 21a side. The other output signal of the reference material control circuit 44 is transmitted to the input terminal of the second electromagnetic coil 33b in the beam driving device 28b on the sample side balance mechanism 21b side via the gain setting unit 46 and the amplification circuit 45b.

  The feedback control circuit 42 further includes a sample side control circuit 47 connected to the output terminal of the light receiving element 40b in the sample side balance mechanism 21b. The sample side control circuit 47 is also configured using, for example, a PID circuit, and its output signal is transmitted to the input terminal of the third electromagnetic coil 33c in the beam driving device 28b on the sample side balance mechanism 21b side via the amplifier circuit 45c. Is done. The TG measurement circuit 43 is connected to the output terminal of the third electromagnetic coil 33c. The TG measurement circuit 43 calculates the weight change of the sample S by calculation based on the current value input to the third electromagnetic coil 33c.

  If the balance beam 23a in the reference-side balance mechanism 21a is tilted for some reason, the position of the slit 38a changes, so that the amount of light received by the light receiving element 40a changes and the output signal changes. The reference substance side control circuit 44 generates and outputs a compensation signal based on the change in the output signal, and the output signal is supplied to the first electromagnetic coil 33a in the reference side beam driving device 28a via the amplifier circuit 45a. The In this way, a current flows through the first electromagnetic coil 33a, and a force is generated by the interaction with the magnet 34a. This force generates a rotational moment in a direction opposite to the inclination of the balance beam 23a, thereby compensating for the inclination. The beam 23a is maintained in a horizontal state.

  On the other hand, the compensation signal output from the reference substance side control circuit 44 is also supplied to the second electromagnetic coil 33b in the sample side beam driving device 28b via the gain setting unit 46 and the amplification circuit 45b. Thereby, the same amount of compensation moment as that of the reference side balance beam 23a is applied to the sample side balance beam 23b. In addition, in the sample side balance mechanism 21b, a change occurs in the output signal of the light receiving element 40b according to the inclination of the balance beam 23b, and the sample side control circuit 47 generates and outputs a compensation signal in accordance with this change. The output signal is supplied to the third electromagnetic coil 33c in the sample side beam driving device 28b through the amplification circuit 45c. Thus, a current flows through the second electromagnetic coil 33b and the third electromagnetic coil 33c in the sample-side beam driving device 28b, and a force is generated by the interaction with the magnet 34b, and this force causes a direction opposite to the inclination of the balance beam 23b. Rotational moment is generated in the lens, the inclination is compensated, and the sample-side balance beam 23b is maintained in a horizontal state. At this time, the weight change of the sample S is calculated by the TG measurement circuit 43 based on the current flowing through the third electromagnetic coil 33c.

  In this embodiment, in addition to feeding back the compensation signal for the inclination of the reference-side balance beam 23a to the reference-side balance beam 23a itself, it is also fed back to the sample-side balance beam 23b. When an influence other than the weight change of S is received, it is possible to prevent unnecessary noise from being generated in a transient control state immediately after that, and TG measurement with high reliability is possible.

  In FIG. 5, fulcrums 22a and 22b, tilt detection mechanisms 37a and 37b, beam drive mechanisms 28a and 28b, and balance beams 23a and 23b (substantially, first beams 24a and 24b) corresponding to the respective parts. The portion corresponding to (1) is stored in the housing 18. The other portions of the balance beams 23 a and 23 b (substantially the portions corresponding to the second beams 25 a and 25 b) extend outside through an opening 19 provided in the side plate of the housing 18.

  In this embodiment, when exchanging the sample S supported by the sample-side balance mechanism 21b, the sample S is exchanged after the sample S is taken out of the protective tube 14 of FIG. 4 by moving the balance unit 6. To do. Hereinafter, a configuration for moving the balance unit 6 in such a manner will be described.

  In FIG. 3, the sample moving device 7 is provided in the lower part of the housing 18. The sample moving device 7 includes a rail 51 fixed on the frame 50, a slider 52 that slides on the rail 51, and a unit substrate 53 fixed on the slider 52. The housing base 16 of the housing 18 is provided on the unit substrate 53 so as to be pivotable about an axis line X0 extending in the vertical direction through the center of the gear member 56 at the rear portion. The configuration for providing the housing base 16 on the unit substrate 53 so as to be rotatable can be arbitrarily selected. For example, the housing base 16 and the substrate 53 are rotatably connected to each other by a shaft member on the axis X0, By guiding the base body 16 with an appropriate guide member, the base body 16 can be turned around the axis line X0.

  In FIG. 3, the sample moving device 7 has an electric motor 54 capable of controlling the rotation speed, for example, a pulse motor or a stepping motor. The output shaft of the motor 54 is drivingly connected to the slider 52, and when the motor 54 operates and the output shaft rotates, the slider 52 slides along the rail 51. Such a slide mechanism can be configured by a mechanism in which a screw shaft is fixed to the output shaft of the motor 54, a female screw meshing with the screw shaft is provided in the slider 52, and these screws are meshed with each other. The rail 51 extends in a straight line, and therefore the slider 52 linearly slides in the left-right direction in the drawing as indicated by an arrow A-A ′. When the slider 52 slides, the housing 18 fixed thereto also slides together.

  3 and 4 show a state in which the housing 18 has moved most in the A ′ direction (left direction in the figure), and in this state, the left end side plate of the housing 18 is in contact with the right end surface of the protective tube 14. In this state, the right opening of the protective tube 14 and the opening 19 of the left side plate of the housing base 16 communicate with each other. As shown in FIG. 4, the reference material R supported by the balance beam 23a of the reference side balance mechanism 21a in the housing 18 and the sample S supported by the balance beam 23b of the sample side balance mechanism 21b are placed inside the protective tube 14, Therefore, it is placed inside the heater 12.

  Thus, the position of the sample S placed inside the heater 12 is the measurement position Ps. Further, the position of the sample-side balance beam 23b where the sample S is placed at the measurement position Ps is the first position of the balance beam. In the following description, the position of the reference material R when the sample S is placed at the measurement position Ps may be referred to as a measurement position. Further, the position of the reference-side balance beam 23a where the reference material R is placed at the measurement position may be referred to as a first position of the balance beam.

  A pipe 62 is provided between the left end of the small diameter portion of the protective tube 14 and the right side wall of the housing base 16 of the balance unit 6, and an exhaust device 63 is provided in the middle of the pipe 62. The exhaust device 63 is configured by, for example, an exhaust pump. When the sample side balance mechanism 21b or the like is in the first position, the left side wall of the housing base 16 and the right side opening of the protective tube 14 are connected in an airtight manner. By operating the exhaust device 63 in this state, the inside of the protective tube 14 and the housing 18 can be set to a vacuum state or a reduced pressure state. The reason why the inside of the protective tube 14 and the housing 18 is set to a vacuum state or a reduced pressure state is that there is a case where it is desired to measure the thermal characteristics of the sample S under a vacuum state or the like, and there is a case where it is desired to replace the target gas atmosphere. is there.

  In the thermal analysis device 1 of the present embodiment, with the balance mechanisms 21a and 21b placed in the first position, the inside of the protective tube 14 is set to a vacuum state as necessary, and then the reference substance R and The sample S is heated by the heater 12 and the weight change of the sample S relative to the reference material R is measured while the temperature is raised according to a predetermined temperature raising program.

  In FIG. 3, when the sample moving device 7 is operated and the housing 18 is linearly slid and moved in the direction of arrow A (rightward in the figure), the housing 18 is linearly moved along the straight line L0 in the direction of arrow A as shown in FIG. By sliding, the left side plate of the housing base 16 is separated from the right end surface of the protective tube 14. When the housing 18 is linearly slid by a distance equal to or longer than the length of the second beams 25a and 25b, the reference material R and the sample S supported at the tips of the beams 25a and 25b are outside the protective tube 14, and thus the sample temperature control. It is taken out of the device 8.

  A gear member 56 is provided on the side surface of the rear end portion of the bottom plate of the housing base 16. A part of the gear member 56 projects to the outside of the housing base 16. The gear member 56 is fixed to the housing base 16 so as not to rotate. A rack 57 is provided in a fixed position at the right corner inside the cover 2. The tooth surface of the rack 57 is provided on the linear movement locus of the tooth surface of the gear member 56. Therefore, when the housing 18 is linearly slid and moved in the direction of arrow A by a predetermined distance, the tooth surface of the gear member 56 meshes with the tooth surface of the rack 57.

  Since the gear member 56 is fixed to the housing base 16 so as not to rotate relative to the housing base 16, and the bottom plate of the housing base 16 can pivot with respect to the substrate 53 about the axis X0, the gear member 56 and the rack 57 are engaged with each other. When the housing 18 further linearly slides in the direction of arrow A (rightward) in this state, the housing 18 turns in the direction of arrow B (counterclockwise) about the axis X0 with respect to the unit substrate 53 as shown in FIG. Move the slide.

  When the housing 18 turns and moves counterclockwise by a predetermined angle in FIG. 8, the reference material R in the housing 18 supported by the balance beam 23a of the reference side balance mechanism 21a and the balance beam 23b of the sample side balance mechanism 21b are supported. The prepared sample S is placed outside the protective tube 14 and thus outside the sample temperature control device 8. More specifically, the sample S is placed at a position that deviates laterally (downward in the figure) from the linear locus indicated by the arrow L0 in FIG. The position of the sample S placed outside the sample temperature control device 8 in this way is the separation position Pr, and the position of the sample-side balance beam 23b that places the sample S at such a separation position Pr is the second position of the balance beam. Position. The separation position Pr can be set on the straight line locus L0 itself in some cases, but in this embodiment, the separation position Pr is set at a position deviating from the straight line locus L0 in the lateral direction.

  When the sample-side balance beam 23b is in the second position, the sample S supported by the sample-side balance beam 23b and at the separation position Pr, and the reference material R supported by the reference-side balance beam 23a are transferred to the operation unit cover 4 It is supposed to go inside. An opening 59 is provided on the upper surface of the operation unit cover 4 and corresponding to the reference material R and the sample S. The opening 59 may be a simple opening, but in this embodiment, the opening 59 is provided with an opening / closing shutter 60. The opening / closing shutter 60 is interlocked with a slide knob 61 provided on the front surface of the operation unit cover 4. When the knob 61 is placed at the right closed position, the shutter 60 is closed, and the knob 61 is moved to the left as shown in the supplementary diagram (a). When the shutter 60 is placed in the open position, the shutter 60 opens. If the shutter 60 is opened when the sample-side balance beam 23b is in the second position, the reference substance R and the sample S can be visually recognized under the opening 59. In this state, the measurer can exchange the sample S using an exchange device such as tweezers. Further, the reference substance R can be exchanged as necessary.

  From the above description, the reference-side balance mechanism 21a and the sample-side balance mechanism 21b in FIG. 4 can be slid from the first position shown in FIG. 4 to the second position shown in FIG. 8 by the function of the sample moving device 7 in FIG. Was understood. Thereafter, when the unit substrate 53 is slid linearly in the direction of arrow A ′ from the state where the sample-side balance mechanism 21 b and the like are in the second position in FIG. 8, the balance unit 6 is moved to the arrow B by the action of the gear member 56 and the rack 57. 'Turn and slide in the direction. Then, when the sample S reaches the linear locus L0 as shown in FIG. 7, the balance unit 6 then linearly slides in the direction of arrow A ′ following the linear slide movement of the substrate 53, and finally the figure S The first position shown at 4 is reached. In this state, TG-DTA measurement can be performed on the sample S.

  In FIG. 3, the blower fan 64 is installed in the left end region of the internal space of the cover 2, and the air supply port of the blower fan 64 is connected to the blower duct 10. When the blower fan 64 is activated, air is blown from the blower duct 10 to the heater 12, and the heater 12 is forcibly cooled. The cooling fins 9 assist the cooling. This cooling process is not performed during the thermal analysis measurement, but is performed in order to quickly cool the sample temperature control device 8 after the measurement. The guide member 65 provided to face the side surface of the housing base body 16 is a guide member that guides the linear slide movement of the housing 18 in the arrow A-A ′ direction.

Hereinafter, the operation of the thermal analyzer 1 having the above configuration will be described.
First, in FIG. 8, the balance unit 6 is set at the second position shown. In this state, the heat sensitive plate 30 b at the tip of the sample-side balance beam 23 b is placed at a separation position Pr that is a position outside the sample temperature control device 8, that is, below the opening 59 of the operation unit cover 4. At this time, the heat sensitive plate 30 a at the tip of the reference side balance beam 23 a is also placed below the opening 59. When the shutter 60 of the opening 59 is opened by operating the knob 61 (see supplementary figure (a)), the heat sensitive plates 30a and 30b can be visually recognized from the opening 59, so that the measurer can detect the heat sensitive plates 30a and 30b. A reference substance R and a sample S are placed on each using tweezers or the like.

  Next, when the shutter 60 is closed and a predetermined start button is pressed, the motor 54 of the sample moving device 7 in FIG. 3 is activated, and the unit substrate 53 in FIG. 8 is linearly slid and moved in the arrow A ′ direction. At this time, due to the meshing action of the gear member 56 and the rack 57, the balance unit 6 pivots and slides in the direction of the arrow B ′ on the substrate 53, and the sample S is placed on the linear locus L0 as shown in FIG. Move to the place.

  Thereafter, the linear slide movement of the unit substrate 53 in the arrow A ′ direction is continuously performed, and the balance unit 6 follows and moves in the arrow A ′ direction. By this movement, the reference material R supported by the reference side balance beam 23 a and the sample S supported by the sample side balance beam 23 b are inserted into the protective tube 14. Finally, the reference-side balance beam 23a and the sample-side balance beam 23b in the balance unit 6 move to the first position shown in FIG. 4 and stop. In this state, the reference material R and the sample S are placed at the measurement position Ps inside the heater 12 of the sample temperature control device 8.

  Next, the reference material R and the sample S are heated by causing the heater 12 to generate heat according to a predetermined temperature raising program by the temperature control circuit 13. When the physical property of the sample S changes during this heating and its weight changes, in FIG. 6, the sample-side balance beam 23b that supports the sample S and the reference-side balance beam 23a that supports the reference material R that does not cause any physical property change. A difference in inclination angle occurs between the feedback control circuit 42 and the TG measurement circuit 43 based on this difference. At the same time, the temperature change of the sample S relative to the reference substance R is measured by the DTA measurement circuit 31 of FIG. Thereby, the measurement data used as the origin of a TG-DTA diagram are obtained.

  When the measurement is completed, a message indicating that is displayed on a display device (not shown) provided at an appropriate position of the thermal analyzer 1 in FIG. 1, and the measurer who sees it displays a button for instructing a process for recovering the sample S (Not shown) is operated. Thereby, the motor 54 of FIG. 3 operates and the balance unit 6 linearly slides in the arrow A direction. When the balance unit 6 moves by a predetermined distance, the reference material R and the sample S are taken out of the protective tube 14 as shown in FIG. When the linear slide movement of the balance unit 6 is further continued, as shown in FIG. 8, the balance unit 6 pivots and slides in the direction of arrow B due to the engagement between the gear member 56 and the rack 57, and this movement causes the balance to move. The reference-side balance beam 23a and the sample-side balance beam 23b in the unit 6 are moved to the illustrated second position.

  When the balance beams 23a and 23b are placed at the second position, the reference material R and the sample S supported by the balance beams 23a and 23b are placed below the opening 59 of the operation unit cover 4, that is, at the separation position Pr. At this time, when a display device (not shown) provided at a predetermined position of the thermal analysis device 1 displays that fact and the measurer who has seen the display desires to take out the sample S or replace the sample S. Operates the knob 61 as shown by the arrow C in the supplementary figure (a) to open the shutter 60. The measurer takes out the sample S through the opened shutter 60 or replaces it with another sample S.

  As shown in FIG. 1, a drawer table 67 is provided below the operation unit cover 4. The drawer table 67 can be pulled out as shown in the supplementary diagram (a). In FIG. 8, when the sample S and the reference material R are taken in and out through the opening 59 where the shutter 60 is open, it is conceivable that the sample S or the like is accidentally dropped. In this case, since the dropped sample S and the like are received by the table 67 inside the operation unit cover 4, the dropped sample S and the like can be easily recovered by pulling the table 67 to the outside as shown in the supplementary diagram (a).

  As described above, according to the thermal analysis device 1 of the present embodiment, when the sample S shown in FIG. 4 is taken out of the sample temperature control device 8, the sample temperature control device 8 is not moved, but the housing 18 The sample-side balance beam 23b is slid to move the sample S, and the sample S is transported to the separation position Pr that is an external position of the sample temperature control device 8 by the slide movement of the balance beam 23b. For this reason, even when the sample temperature control device 8 is heavy or when the sample temperature control device 8 is provided with auxiliary equipment such as a gas transfer tube, the structure for exchanging the sample S is shown in the case of this embodiment. 3 sample moving device 7 is very small and can be constructed easily.

  In FIG. 4, when the balance beams 23a and 23b start linear sliding movement from the first position shown in the figure to the arrow A direction, or in FIG. 8, the balance beams 23a and 23b turn from the second position shown in the figure to the arrow B ′ direction. When starting the slide movement, it is desirable to gradually increase the moving speed of the balance beams 23a and 23b toward a predetermined speed. That is, it is desirable to perform a so-called slow start. Further, when the balance beams 23a and 23b are stopped at the first position (FIG. 4) or the second position (FIG. 8), it is desirable to gradually decrease the moving speed of the balance beams 23a and 23b. That is, it is desirable to perform a so-called slow stop. These speed controls can prevent the balance beam from being damaged or deformed, and the sample or the like from falling off the balance beam. These speed controls can be performed, for example, by controlling the rotational speed of the motor.

  In FIG. 7, when the balance beams 23a and 23b that have finished the linear slide movement in the direction of arrow A start the swivel slide movement in the direction of arrow B in FIG. 8, and the balance that has finished the swivel slide movement in the direction of arrow B ′. When the beams 23a and 23b start linear sliding movement in the direction of arrow A ′, it is desirable that the moving speed of the balance beams 23a and 23b is gradually increased toward a predetermined speed. These speed controls can prevent the balance beam from being damaged or deformed, and the sample or the like from falling off the balance beam. These speed controls can also be performed, for example, by controlling the rotational speed of the motor. Further, by changing the tooth profile shapes of the gear member 56 and the rack 57, the speed control thereof can be performed.

  As shown in FIG. 1, since all the mechanisms for performing thermal analysis measurement are installed in a space surrounded by the cover 2, the covers 3a to 3c and the operation unit cover 4, the balance beam or the like is brought into the atmosphere. Accurate weighing can be performed without exposure. Further, as shown in FIG. 8, since the opening 59 is provided in the operation unit cover 4 corresponding to the separation position Pr of the sample S, the sample S and the like can be easily taken in and out through the opening 59.

  In the present embodiment, as shown in FIG. 8, the position that deviates from the linear locus L0 of the sample S in the lateral direction (downward in the figure) is defined as the separation position Pr of the sample S. With this configuration, even if the sample S is dropped from the balance beam 23b, the sample S can be prevented from hitting the main mechanism portion in the thermal analyzer 1 and damaging the mechanism portion. In addition, by setting the position deviated from the linear locus L0 of the sample S in the lateral direction as the separation position Pr of the sample S, the sample S can be carried near to the measurer, and the sample can be easily exchanged. It became.

  In FIG. 5, the second beams 25a and 25b constituting the balance beams 23a and 23b are detachable from the first beams 24a and 24b. As shown in the supplementary figure (b), this attachment / detachment is performed by attaching or removing the plug portions 27a, 27b on the second beam 25a, 25b side to the socket portions 267a, 26b on the first beam 24a, 24b side. Done. In the conventional thermal analyzer, since the housing 18 is formed of an opaque metal material or an opaque resin material, the upper lid of the housing 18 is removed when the plug portion and the socket portion are attached and detached as described above. The housing 18 was attached and detached in an open state so that the inside of the housing 18 was visible. The work of attaching and detaching the upper lid was very troublesome. On the other hand, in this embodiment, since the upper lid 17 of the housing 18 is formed of a transparent material, the connection portions of the balance beams 23a and 23b can be visually recognized through the upper lid 17. For this reason, the first beams 24a and 24b and the second beams 25a and 25b can be attached and detached without removing the upper lid 17, and the second beams 25a and 25b can be attached and detached very easily. It became so.

  According to the present embodiment, the first beam 24a, 24b and the second beam 25s, 25b can be attached and detached while observing the balance beams 23a, 23b through the transparent cover 17 in FIG. It is not necessary to remove the top cover of the housing 18 every time the beams 25a and 25b are exchanged or detached. For this reason, the attaching / detaching operation of the second beams 25a and 25b is very simple, and the internal structure of the housing 18 and the balance mechanisms 21a and 21b are not damaged.

(Other embodiments)
In the above-described embodiment, as shown in FIG. 5, the transparent cover 17 is fixed to the upper surface of the housing 18 so that the entire upper surface of the housing 18 is a transparent portion. Alternatively, a part of the upper side plate of the housing 18 can be a transparent portion. Of course, the transparent part in this case is a transparent part in which the connection part of the first beam 24a, 24b and the second beam 25a, 25b in the balance beam 23a, 23b is a visible region.

  When the transparent cover 17 is formed of an acrylic resin, reflected light may be generated depending on the viewing angle (the angle viewed by the operator), and the visibility inside the housing 18 may be impaired. In order to avoid this light reflection phenomenon, an AR (Anti-Reflection) film or an AR coating is applied to the front or back surface of the transparent cover 17 corresponding to the vicinity of the connecting portion of the balance beam. Is desirable.

  If necessary, the transparent cover 17 corresponding to the connecting portion of the balance beam can be molded into a lens shape, or a lens (for example, a Fresnel lens) can be attached to the portion. If it carries out like this, the connection part of a balance beam can be visually recognized now in an expanded state, and the attachment or detachment work of a balance beam can be performed more correctly.

  Further, if necessary, a lighting device can be provided at a suitable position inside or outside the housing 18. Thereby, even if the place where the thermal analyzer is placed is in a dark state, it is possible to accurately attach and detach the balance beam by turning on the illumination device. In particular, this illumination method is advantageous when a transparent portion is provided on a part of the upper surface of the housing 18.

  In the above embodiment, as shown in FIG. 8, the position deviated laterally from the linear locus L0 of the sample S is set as the separation position Pr of the sample S. Instead, an appropriate position on the linear locus L0 can be set as the isolation position Pr of the sample S. Even in this case, it is possible to achieve the object of the present invention to enable the sample exchange by moving the balance beam 23b without moving the sample temperature control device 8.

  In the above embodiment, as shown in FIG. 5, in addition to the balance mechanism 21b for the sample S, the balance mechanism 21a for the reference material R is used. However, the present invention can also be applied to a TG device configured to use only one balance mechanism 21b for the sample S without using the balance mechanism 21a for the reference substance R.

1 is a perspective view showing the overall appearance of an embodiment of a thermal analyzer according to the present invention. It is a perspective view which shows the state which removed the upper cover of the thermal analyzer shown in FIG. It is front sectional drawing of the thermal analyzer shown in FIG. FIG. 3 is a plan sectional view of the thermal analyzer shown in FIG. 2. FIG. 5 is a plan sectional view showing a balance unit that is a main part of the thermal analysis apparatus shown in FIG. 4. It is a figure which shows the side structure and accompanying electric circuit of the balance unit shown in FIG. It is a figure which shows the operation state of the structure shown in FIG. It is a figure which shows the other operation state of the structure shown in FIG.

Explanation of symbols

1. 1. Thermal analysis device Body cover, 3a-3c. Upper cover, 4. Operation unit cover,
6). 6. Balance unit Sample moving device, 8. 8. Sample temperature control device, Cooling fins,
10. Air duct, 12. Heater, 14. Protection tube, 16. Housing base,
17. Transparent cover, 18. Housing, 19. Opening, 21a. Reference side balance mechanism,
21b. Sample-side balance mechanism, 22a, 22b. Torsion wire (fulcrum),
23a. Reference side balance beam, 23b. Sample-side balance beam,
24a, 24b. First beam, 25a, 25b. The second beam,
26a, 26b. Socket part, 27a. 27b. Plug part,
28a, 28b. Beam driving device, 29a, 29b. mark,
30a, 30b. Heat sensitive plate, 33a. First electromagnetic coil, 33b. A second electromagnetic coil,
33c. 3rd electromagnetic coil, 34a, 34b. Magnets 35a, 35b. Balance weight,
37a, 37b. Tilt detection mechanism 38a, 38b. slit,
39a, 39b. Light source, 40a, 40b. Light receiving element,
42. Feedback control circuit, 50. Frame, 51. rail,
52. Slider, 53. Unit substrate, 54. Electric motor, 56. Gear members,
57. Rack, 59. Opening, 60. Open / close shutter, 61. Slide knob,
62. Piping, 63. Exhaust device, 64. Blower fan, 65. Guide members,
67. Drawer table, R.D. Reference substance, S. Sample, L0. Linear trajectory

Claims (5)

A balance beam formed by connecting the first beam and the second beam;
A fulcrum that supports the first beam so as to be capable of tilting and swinging;
A housing containing the fulcrum and the first beam and having an opening;
The second beam is inserted into the housing through the opening, connected to the first beam, extends to the outside of the housing, and supports the sample at an end opposite to the end on the connection side. ,
The thermal analysis apparatus according to claim 1, wherein a transparent portion having a connection portion between the first beam and the second beam as a visible region is provided in the housing.   2. The thermal analysis apparatus according to claim 1, wherein one of the first beam and the second beam has a plug to be inserted, and the other has a socket for receiving the insertion, and the first beam and the The second beam is connected to each other by fitting a plug and a socket.   3. The thermal analysis apparatus according to claim 2, wherein the plug or socket included in the first beam has a mark in a visible region of the transparent portion, and the socket or plug included in the second beam is the first beam. A thermal analyzer having a mark corresponding to the mark.   4. The thermal analysis apparatus according to claim 1, wherein the housing includes a box-shaped housing base whose upper surface is opened, and a transparent cover fixed to the upper surface of the housing base. 5. The thermal analysis apparatus is characterized in that the transparent part is formed by the transparent cover. Sample temperature control means for surrounding the sample and controlling the temperature of the sample;
A balance unit that moves between a position coupled to the sample temperature control means and a position away from the sample temperature control means;
The balance unit is
A balance beam formed by connecting the first beam and the second beam;
A fulcrum that supports the first beam so as to be capable of tilting and swinging;
A housing containing the fulcrum and the first beam and having an opening;
The second beam is inserted into the housing through the opening, connected to the first beam, extends to the outside of the housing, and supports the sample at an end opposite to the end on the connection side. ,
A transparent portion having a connection portion between the first beam and the second beam as a visible region is provided in the housing,
The thermal analysis apparatus according to claim 1, wherein the second beam in a portion extending to the outside of the housing is disposed inside the sample temperature control means when the housing is coupled to the sample temperature control means.

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