JP5155751B2 - Elemental analyzer - Google Patents

Description

  The present invention relates to an element analyzer for analyzing elements such as nitrogen (N), hydrogen (H) and oxygen (O) contained in a measurement sample such as steel, non-ferrous metal, and ceramics, and more particularly to an element analyzer. The present invention relates to a cleaning unit for cleaning the upper electrode and the lower electrode and a transport unit for transporting the crucible onto the lower electrode.

This type of elemental analyzers, for example, as shown in Patent Document 1, to accommodate the sample to be measured sandwiched crucible to the upper electrode and the lower electrode, by applying a voltage, heating the sample in the crucible The element of the measurement sample is analyzed by analyzing the gas generated by dissolution.

As described above, the upper electrode and the lower electrode are in contact with the graphite crucible, and part of the dissolved measurement sample, flux, etc. is scattered and attached, so that the upper electrode and the lower electrode are contaminated. When the electrode surface is dirty, the dirt becomes electric resistance, the crucible when pinched, hardly current flows through the crucible becomes insufficient heat, such as the measurement sample, extraction of the analyzing gas There is a problem such as a decrease in performance.

  Accordingly, it is necessary to clean the upper electrode and the lower electrode after extraction of the analysis gas is completed.

  Conventionally, as an apparatus for cleaning the upper electrode and the lower electrode, there is an automatic cleaning device disclosed in Patent Document 2.

  This automatic cleaning device moves a cleaning unit having a rotating brush for cleaning an upper electrode and a rotating brush for cleaning a lower electrode, by a pneumatic cylinder along a horizontal guide bar, so that the rotating brush moves to the upper electrode and the lower electrode. Is moved forward and backward between a facing position opposite to and a retracted position separated from the facing position. The cleaning unit of the automatic cleaning apparatus includes a crucible holder (used crucible removing means), and the crucible holder adsorbs the crucible on the lower electrode while the cleaning unit moves horizontally to the opposing position. By doing so, the crucible is removed.

  When the cleaning unit reaches the facing position, the lower electrode is raised to raise the cleaning unit, press the rotary brushes against the electrodes, rotate the rotary brushes, and clean the electrodes. It is to do.

  However, if the cleaning unit moves straight in the horizontal direction, the guide bar and the air cylinder become larger as the facing position and the retracted position are further away from each other, and the automatic cleaning mechanism becomes enlarged. There is also a problem that the elemental analyzer becomes enlarged.

Further, in the conventional elemental analyzer, a crucible is placed on the lower electrode with tweezers or the like, and the work is extremely troublesome, which hinders the automation of analysis. Furthermore, it is conceivable to provide a separate transport unit. However, if a transport unit is provided in addition to the cleaning unit, an increase in manufacturing cost and enlargement of the elemental analyzer are not hindered.
Japanese Patent No. 2949501 Japanese Patent Publication No.58-23886

  Therefore, the present invention has been made to solve the above problems all at once, changing the driving method of the conventional cleaning unit, adding a transport function to the cleaning unit, and The main objective is to automate the supply, the disposal of the crucible from the lower electrode, and the cleaning of the lower electrode or the upper electrode by a simple mechanism, and to enable the element analyzer to be miniaturized.

That elemental analyzer of the present invention, the upper and lower electrodes, a crucible for containing a sample is sandwiched, by applying a voltage to the electrodes, and heating the crucible, the sample from the thereby producing gas An elemental analysis apparatus for analyzing the element of the above, wherein the crucible is transported from the crucible installation part where the crucible is installed onto the lower electrode, and includes a transport / cleaning unit for cleaning the upper electrode or the lower electrode, A cleaning unit supports a cleaning body for cleaning the upper electrode or the lower electrode, an arm unit having a gripping claw for gripping a crucible installed in the crucible installation unit, and the arm unit by a rotation shaft. , A position where the cleaning body faces the upper electrode or the lower electrode, a placement position where the crucible gripped by the gripping claws is placed on the lower electrode, and the facing position Beauty said arm portion in rotational movement to each spaced a retracted position from the placement position, characterized in that it comprises a rotary drive mechanism for stopping.

  If this is the case, the cleaning unit for cleaning the upper electrode or the lower electrode and the arm unit including the gripping claws for gripping the crucible are rotated to move to the facing position, the mounting position, and the retracted position, respectively. Therefore, the crucible can be transported, discarded, and the electrodes can be automated by a simple mechanism, and the elemental analyzer can be miniaturized.

When placing the crucible on the lower electrode by the transport unit, when every time the analysis result is placed in the same position, would be the same portion wear of the upper and lower electrodes which sandwich the crucible, There exists a problem that the lifetime of an upper electrode and a lower electrode will become short. In order to solve this problem and to extend the life of the upper electrode and the lower electrode, the position of the crucible on the lower electrode is changed each time the rotary drive mechanism places the crucible on the lower electrode. It is desirable that the mounting position is different every time the arm unit is moved to the mounting position.

  As described above, according to the present invention, the transport mechanism that transports the crucible onto the lower electrode and the cleaning unit that cleans the lower electrode are integrated, the crucible is supplied to the lower electrode, the crucible is discarded from the lower electrode, and the lower electrode or The cleaning of the upper electrode can be automated by a simple mechanism, and the element analyzer can be reduced in size and cost.

  Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a schematic configuration diagram of the elemental analyzer 100 according to the present embodiment, FIG. 2 is a schematic cross-sectional view showing the configuration of the crucible supply mechanism 2, and FIG. 3 shows the electrode portion of the elemental analyzer and the transport / cleaning unit 3. 4 is a diagram showing each stop position of the arm portion, FIG. 5 is a schematic diagram showing the retracted position R2, FIG. 6 is a diagram showing the gripping position R3, and FIG. 7 is a diagram showing the placement position R4. 8 is a view showing the disposal position R5, FIG. 9 is a view showing the facing position R1, and FIG. 10 is a view showing a cleaning stage.

  <Device configuration>

  The elemental analysis apparatus 100 according to the present embodiment heats and dissolves a metal sample (hereinafter also simply referred to as a sample) accommodated in the crucible R, and analyzes the gas components generated at that time, thereby analyzing the sample. Measuring the contained elements, the analyzer main body 1, the crucible supply mechanism 2 for supplying the crucible conveyed to the analyzer main body, and the crucible supplied by the crucible supply mechanism 2 are used as the analyzer main body. And a transport / cleaning unit 3 for cleaning the analyzer main body 1. Each will be described below.

    << Analyzer body 1 >>

If it demonstrates from the analyzer main body 1, as shown in FIG. 1, the upper electrode 12 and the lower electrode 11 are provided in the front surface of this analyzer main body 1 at intervals up and down, and a sample is provided on the lower electrode 11. It is comprised so that the crucible R which accommodated can be mounted. The crucible position placed on the lower electrode 11 in the lowered position shown in FIG. 1 is the heating position P1. In FIG. 1, reference numeral 13 denotes a detection sensor (for example, a photoelectric sensor) that detects the presence or absence of a crucible on the lower electrode 11. The crucible R is made of graphite having a cylindrical shape with an open top, and the lower end has a tapered shape. In addition, the crucible R may be one in which an annular concave groove is formed on the outer periphery of the lower end portion in addition to a taper shape whose lower end portion is tapered.

  At the time of analysis, the lower electrode 11 slides upward with respect to the crucible R placed at the heating position P <b> 1, and the crucible R is sandwiched between the upper electrode 12. In this state, when a sample is loaded into the crucible R from the sample loading portion 14 provided above the upper electrode 12, a current is then applied between the electrodes 11 and 12, and the crucible R generates heat to generate heat. The sample is heated and melted. The gas generated from the melted sample is sent to an analysis unit (not shown) to measure the components, and from the result, the element originally contained in the sample is analyzed.

  For example, when measuring the amount of oxygen in a sample, CO (carbon monoxide), which is a reaction product, is generated by melting the sample, and the CO is detected using, for example, a non-dispersive infrared detector that constitutes the analysis unit. Measure and calculate the amount of oxygen present in the sample based on the CO value. In addition, components such as hydrogen nitrogen can be measured by setting a reaction product and an analysis unit corresponding to the reaction product. After the analysis, the used crucible R is discarded together with the sample by the crucible transport mechanism 2.

    << Crucible supply mechanism 2 >>

  The crucible supply mechanism 2 automatically supplies a crucible R conveyed by a conveyance / cleaning unit 3 to be described later. In particular, as shown in FIG. 2, a crucible accommodating portion 21 capable of accommodating a plurality of crucibles R And a guide path 22 for dropping the crucible R from the crucible housing part 21 by its own weight, and a crucible installation part 23 provided in the outlet 22b of the guide path 22 for receiving the dropped crucible R.

  The crucible housing part 21 holds an inclined surface 211 on which a plurality of crucibles R are placed in parallel, a discharge port 212 provided below the inclined surface 211, and a crucible R sliding down below the inclined surface 211. And a crucible discharge mechanism 213 that moves to the discharge port 212. The crucible discharging mechanism 213 includes, for example, a rotating body (see FIG. 1) that has a concave portion that accommodates the crucible R on its side surface and rotates around one axis, and a drive unit (not shown) that rotates the rotating body. It is possible to move the crucible R accommodated in the recess to the discharge port 212 by rotating it. Then, the crucible R moved to the upper portion of the discharge port 212 by the crucible discharge mechanism 213 falls from the discharge port 212 and is discharged by its own weight. In this case, since the crucibles R are accommodated in parallel, as many crucibles R as possible can be accommodated. Further, since the discharge is performed using the dead weight of the crucible R, the structure of the discharge mechanism 213 can be simplified.

  The guide path 22 drops the crucible R in a substantially vertical direction and guides the crucible R to the crucible installation part 23. As shown in FIG. 2, the guide path 22 communicates with the supply port 214 of the crucible accommodating part 21 and is substantially vertically. Is formed.

  In addition, the guide path 22 is for dropping the crucible R introduced from the crucible housing portion 21 in a vertically positive state, and when the crucible R falls, the inner diameter that does not turn upside down, for example, the longest of the crucible R The inner diameter is smaller than the length of the diagonal.

  On the side wall of the guide tube 5, foreign matter other than the crucible R introduced from the supply port 214 (for example, fragments of the crucible R) is discharged outside the guide tube 5 without reaching the outlet (outlet port 22 b). For example, one or a plurality of slit-shaped through holes 5A are provided. Specifically, in the guide tube 5, a through hole 5 </ b> A is provided below the side wall of the bent portion 51 provided substantially perpendicular to the inclined surface 211. Thereby, the fragments are discharged out of the guide tube 5 through the through holes 5A by their own weight. Further, the clogging of the crucible R in the guide path 22 can be confirmed by the through hole 5A.

  Further, a tapered portion 221 for reducing the falling speed of the crucible R is formed in the vicinity of the exit of the guide path 22. The minimum diameter of the taper portion 221 is slightly larger than the outer diameter of the crucible R, and the crucible R can pass through. Further, the downstream side of the tapered portion 221 in the guide path 22 has the same diameter as the minimum diameter of the tapered portion 221. In this case, the falling speed of the crucible R in the vicinity of the exit of the guide path 22 can be reduced, and damage to the crucible R when landing on the crucible installation portion 23 can be prevented. Moreover, the position shift of the installation position in the crucible installation part 23 can be prevented, and it can install accurately.

  The crucible installation part 23 is provided in the front-end | tip part of the drive shaft 241 of the installation part raising / lowering mechanism 24 which consists of an air cylinder etc. which were provided in the base 101, as shown in FIG.1 and FIG.2. The crucible installation unit 23 is connected to the guide path 22 and moves up and down between a receiving position Q1 that receives the crucible R that has fallen and a crucible conveying position Q2 that is a separated position vertically below the receiving position Q1. It is something that moves.

  Specifically, as shown in FIG. 2, the crucible installation portion 23 has a recess 231 x that can accommodate the crucible R, and is provided in the crucible receiving body 231 that receives the crucible R, and in the recess 231 x of the crucible receiving body 231. Mounting protrusions 232.

  The crucible receiving main body 231 has a substantially bottomed cylindrical shape and is formed of a transparent resin whose inside can be visually recognized. The inner diameter of the concave portion 231x is larger than the outer diameter of the crucible R. A tapered surface 231t is formed on the outer peripheral surface of the upper end portion of the crucible receiving body 231. Then, as the crucible installation portion 23 moves from the crucible transport position Q2 to the receiving position Q1, the crucible receiving body 231 is fitted with the tapered surface 5t provided on the outlet side end surface of the guide tube 5 forming the guide path 22. And the positioning function which positions the mounting protrusion 232 and the guide path 22 is demonstrated (refer FIG. 2).

  The mounting protrusion 232 has a substantially cylindrical shape, and its diameter is set slightly smaller than the opening diameter of the crucible R. The mounting protrusion 232 is provided coaxially within the recess 231x of the crucible receiving body 231. When the crucible R is installed in the vertical direction, the crucible R is mounted on the substantially horizontal upper surface 232a. The On the other hand, the mounting protrusion 232 is accommodated in the crucible R when the crucible R is installed upside down. With this configuration, the height position of the crucible R in the crucible installation portion 23 differs depending on whether the crucible R is installed in the upside down direction or when the crucible R is installed upside down.

  Moreover, the length of the mounting protrusion 232 is longer than any depth dimension in the various crucibles R used, and the size of the crucible R is not limited. That is, the length of the mounting protrusion 232 is a length that prevents the opening of the crucible R from coming into contact with the bottom surface of the recess when it is installed upside down. That is, the length of the mounting protrusion 232 is set so that a space is formed between the bottom surface of the recess and the opening end surface of the crucible R when installed in the upside down direction. Thereby, even if foreign matter such as fragments of the crucible R is accumulated in the recess 231x, the crucible receiving body 231 can accommodate the crucible R upside down.

  Further, as shown in FIGS. 1 and 2, the crucible supply mechanism 2 includes a crucible detection sensor 41 and constitutes the reversal detection mechanism 4 together with the crucible installation portion 23.

  The crucible detection sensor 41 uses light to detect the crucible R when the crucible R is installed on the mounting protrusion 232 in the vertical direction. Specifically, a photoelectric sensor is used, and the trajectory of the light L1 that exits the light emitting portion of the photoelectric sensor 41 and reaches the light receiving portion is the outer peripheral surface of the crucible R that is installed in the crucible installation portion 23 in the vertical direction. It is configured to reflect and reach the light receiving unit.

  With such a configuration, when the crucible R is installed vertically upward, the light L1 emitted from the light emitting unit is reflected by the side surface of the crucible R and received by the light receiving unit. On the other hand, when the crucible R is installed upside down, the light L1 emitted from the light emitting unit is not reflected by the outer peripheral surface of the crucible R and is not received by the light receiving unit. As described above, if the crucible R is not installed in the crucible installation part 23, or if the crucible R is installed upside down even if installed, the light receiving unit does not receive the light L1. Inversion of the crucible R can be detected. Further, the detection signal of the light receiving unit is output to notifying means (not shown) so as to notify the operator with an alarm sound or the like. The crucible detection sensor 41 is not limited to the reflective type described above, and may be a transmissive type or a type using ultrasonic waves.

    << Conveying / cleaning unit 3 >>

  The transport / cleaning unit 3 transports and places the crucible R on the lower electrode 11 from the crucible installation portion 23 where the crucible R is installed, or transports the crucible R on the lower electrode 11 to the disposal box 7 and discards it. At the same time, the upper electrode 12 and the lower electrode 11 are cleaned.

  Specifically, this includes an arm part 31 having a first cleaning body 311, a second cleaning body 312, and a gripping claw 313 as a gripping part, and the arm part 31 supported by a rotating shaft 322, and the rotating shaft 322. , And a rotation drive mechanism 32 that rotates the arm portion 31 around the rotation shaft 322.

  The arm portion 31 has a base end portion connected to a rotation shaft 322 of a rotation drive mechanism 32 described later, holds the first cleaning body 311 on the upper electrode 12 side of the distal end portion, and the second cleaning body on the lower electrode 11 side. 312 is held. A gripping claw 313 that grips the crucible R is provided on a side surface of the arm portion 31 that faces the traveling direction toward the lower electrode 11.

  The 1st cleaning body 311 (upper electrode cleaning body) cleans the upper electrode 12, as shown in FIG. 3, and is a rotating brush in this embodiment. Specifically, the first cleaning body 311 includes a first electrode surface brush 311a for cleaning the electrode surface 121 of the upper electrode 12, a passage hole brush 311b for cleaning the sample passage hole 12a of the upper electrode 12, The first base 311c that holds the brushes 311a and 311b.

  The 1st electrode surface brush 311a consists of brush hair made from stainless steel, for example, and the passage hole brush 311b consists of brush hair made from nylon, for example. Further, the passage hole brush 311b is provided on the tip side of the electrode surface brush 311a. The first base 311c is fixed to a first drive shaft 64 of the cleaning body rotating mechanism 6 described later.

  As shown in FIG. 3, the second cleaning body 312 (lower electrode cleaning body) cleans the lower electrode 11, and is a rotating brush like the first cleaning body 311. Specifically, the second cleaning body 312 includes a second electrode surface brush 312a for cleaning the electrode surface 111 of the lower electrode 11, and a peripheral brush 312b for cleaning the peripheral portion of the electrode surface 111 of the lower electrode 11. And a second base 312c for holding the brushes.

  The second electrode surface brush 312a is made of, for example, stainless brush hair, and the peripheral brush 312b is made of, for example, nylon brush hair. A peripheral brush 312b is provided outside the second electrode surface brush 312a. The second base 312c is fixed to a second drive shaft 65 of the cleaning body rotating mechanism 6 described later.

At least one of the gripping claws 313 has, for example, a generally square shape. Each gripping claw 313 uses an air chuck mechanism, and is slidably held on the arm portion 31 at the base end portion. Between the gripping claws 313 by a command from a separately provided control device (not shown). The side circumferential surface of the crucible R can be clamped and gripped between the central portions of the gripping claws 313 by sliding so as to reduce the distance.

  The arm portion 31 has an intake passage 31A inside (see FIG. 3). The intake passage 31A has a connection port formed on the upper surface on the proximal end side of the arm portion 31, an upper electrode side opening formed on the upper surface on the distal end side of the arm portion 31, and a lower electrode side opening provided on the lower surface on the distal end side of the arm portion 31. It communicates with. The upper electrode side opening is formed to be concentric with the first drive shaft 64.

  Furthermore, a hollow coupling body 33 made of an elastic material is provided on the upper surface on the base end side of the arm portion 31 so as to communicate with the connection port. And when the arm part 31 in opposing position R1 raises, the connection body 33 connects with the suction port 102A provided in the frame 102 of the base 101. FIG. The suction port 102A is connected to a suction device (not shown) provided outside the device 1. The raising / lowering movement of the arm part 31 in the facing position R1 is performed by the installation part raising / lowering mechanism 24 described above. The arm portion 31 has a contact piece 31x that comes into contact with the tip of the drive shaft 241 of the installation portion lifting mechanism 24 at the facing position R1. The contact piece 31x is substantially L-shaped and is provided on the side surface of the arm portion. The drive shaft 241 of the installation unit elevating mechanism 24 may be configured to contact the bottom surface of the arm unit 31 and lift the arm unit 31.

Further, in the arm portion 31, a seal member 34 that contacts the lower surface of the upper electrode 12 is provided at the opening edge of the upper electrode side opening. The lower electrode side opening is formed by a side wall provided upright around the second cleaning body 312. The side wall 314, when the arm portion 31 is sandwiched by the upper electrode 12 and lower electrode 11, the distance between the lower electrode 11 and the second cleaning body 312, i.e., the second cleaning body against the electrode surface 111 of the lower electrode 11 The height of 312 is adjusted.

  Further, the arm unit 31 is provided with a cleaning body rotating mechanism 6 for rotating the first cleaning body 311 and the second cleaning body 312. As shown in FIG. 3, the cleaning body rotating mechanism 6 includes an actuator 61 such as a motor fixed to the lower surface of the base end side of the arm portion 31, a first pulley 62 fixed to the drive shaft of the actuator 61, and an arm A second pulley 63 provided on the distal end side of the portion 31, a transmission belt 63 for transmitting the rotational drive of the first pulley 62 to the second pulley 63, and an upper surface of the second pulley 63. The first drive shaft 64 connected to the first base 311c of 311 and the second drive shaft 65 provided on the lower surface of the second pulley 63 and connected to the second base 312c of the second cleaning body 312. The actuator 61 is controlled by the control device.

  As shown in FIG. 3, the rotation drive mechanism 32 supports the arm unit 31 by a rotary shaft 322 so as to be movable up and down, and rotates the arm unit 31, and the cleaning bodies 311 and 312 correspond to the electrodes 11 and 12. The arm portion 31 is rotated and moved between a facing position R1 that faces the arm and a retracted position R2 that is spaced from the facing position R1. The rotation drive mechanism 32 can stop the arm unit 31 at a plurality of rotation positions between the facing position R1 and the retracted position R2.

  A specific configuration of the rotation drive mechanism 32 includes a fixed portion 321 to which the arm portion 31 is fixed, and a rotary shaft 322 that is inserted in a through hole provided in the fixed portion 321 so as not to be relatively rotatable and to be slidable in the axial direction. And an actuator 323 that is coupled to the lower end of the rotary shaft 322 and rotates the rotary shaft 322. These are fixed to the apparatus main body 11 by a bracket 324. The actuator 323 is a stepping motor and is controlled by a drive pulse from a control device (not shown).

  When the rotary shaft 322 is rotated by the actuator 323 by such a drive lifting mechanism 32, the arm portion 31 that cannot rotate relative to the rotary shaft 322 also rotates. Thereby, the arm part 31 rotates between the opposing position R1 and the retracted position R2 with the rotation shaft 322 as the rotation center.

  The rotating shaft 322 and the fixed portion 321 are slidable in the axial direction. As the arm portion 31 is pushed up by the installation portion lifting mechanism 24, the arm portion 31 slides on the rotating shaft 322 and rises.

  Specifically, as shown in FIG. 4, the rotation drive mechanism 32 includes a facing position R <b> 1 where each cleaning body 311, 312 faces each electrode 11, 12, a gripping position R <b> 3 for gripping the crucible R on the crucible installation part 23, A mounting position R4 for placing the crucible R gripped by the gripping claws 313 on the lower electrode 11; a disposal position R5 for discarding the crucible R gripped by the gripping claws 313 in the disposal box 7; The arm part 31 can be stopped at the position R2. The retreat position R2 is located outside the lower electrode 11 and the crucible installation part 23 with respect to the respective stop positions R1, R3 to R5.

  Further, the transport / cleaning unit 3 of the present embodiment includes an arm unit lifting mechanism (not shown). This arm lifting mechanism exhibits a function of lifting the arm 31 vertically upward when the gripping claw 313 grips the crucible R on the crucible installation portion 23 in a state where the arm 31 is in the gripping position R3. Is. Specifically, the arm unit elevating mechanism includes a drive shaft that contacts the lower surface of the arm unit 31 and moves up and down, and an air cylinder that moves the drive shaft up and down. The air cylinder is controlled by the control device. If this is the case, the crucible R accommodated in the crucible receiving body 231 of the crucible installation portion 23 can be lifted and taken out.

    << Operation of transport / cleaning unit 3 >>

  Next, the operation of the transport / cleaning unit 3 configured as described above will be described.

  In the crucible supply stage, the crucible installation part 23 of the crucible supply mechanism 2 rises to the receiving position Q1, receives the crucible R falling from the crucible accommodating part 21 to the guide path 22, and descends to the transport position Q2. At this time, the arm portion 31 of the transport / cleaning unit 3 is in the retracted position R2 (see FIGS. 4 and 5).

  In the crucible transport stage, the transport / cleaning unit 3 rotates and moves the arm portion 31 at the retracted position R2 to the gripping position R3 by the rotation drive mechanism 32 (see FIGS. 4 and 6). At this time, the gripping claws 313 provided on the side surface of the arm part 31 grip the crucible R installed in the crucible installation part 23. Thereafter, the arm portion 31 is slightly lifted by the arm portion lifting mechanism. The amount to be lifted at this time is such that the crucible R comes out of the crucible receiving body 241 of the crucible installation portion 23.

  Next, the arm portion 31 is rotationally moved from the gripping position R3 to the mounting position R4 by the rotation drive mechanism 32 (see FIGS. 4 and 7). During this rotational movement, the arm unit 31 remains slightly lifted by the arm unit lifting mechanism.

  Then, when the arm unit 31 reaches the mounting position R4 and the crucible R is mounted on the lower electrode 11, the arm unit lifting mechanism lowers the arm unit 31. At this time, the arm portion 31 is lowered, and the gripping claws 313 release the crucible R in a state where the bottom surface of the crucible R gripped by the gripping claws 313 is in surface contact with the electrode surface 111 of the lower electrode 11. Thereby, the crucible R is placed so as to be pressed onto the lower electrode 11, and even if the gripping claws 313 are holding the crucible R diagonally, in the process of being pressed against the lower electrode 11, Since the lower surface of the crucible R contacts the electrode surface 111 of the lower electrode 11 and changes its direction, the crucible R can be stably placed on the lower electrode 11, and the crucible R is dropped from above to lower the lower electrode. 11 can be prevented from bouncing over.

  After placing the crucible R on the lower electrode 11, the arm portion 31 is rotationally moved to the retracted position R2 by the rotation drive mechanism 32 (see FIG. 4).

Thereafter, in the analysis stage, the lower electrode 11 is increased, the crucible R nipped between the upper electrode 12, the sample is turned, the analysis of the sample is performed. After the analysis is completed, the lower electrode 11 descends and returns to the lowered position.

  Next, in the crucible disposal stage, the arm portion 31 is rotationally moved from the retraction position R2 to the placement position R4 by the rotation drive mechanism 32 (see FIGS. 4 and 7). Then, the crucible R on the lower electrode 11 is gripped by the gripping claws 313.

  The arm portion 31 holding the crucible R on the lower electrode 11 is rotated and moved to the disposal position R5 by the rotation drive mechanism 32 to release the crucible R at the disposal position R5, and a disposal box provided below the disposal position R5. The crucible R is dropped to 7 (see FIGS. 4 and 8).

  Thereafter, in the electrode cleaning stage, the arm portion 31 is rotationally moved from the disposal position R5 to the facing position R1 by the rotation drive mechanism 32 (see FIGS. 4, 9, and 10A). At this time, the first cleaning body 311 and the second cleaning body 312 are rotated by the cleaning body rotating mechanism 6.

  Then, the tip of the drive shaft 241 of the installation unit elevating mechanism 24 comes into contact with the contact piece 31x and lifts the arm unit 31. At this time, the seal member 34 provided on the upper surface on the distal end side of the arm portion 31 contacts the lower surface of the upper electrode 12 (FIG. 10B). Further, the brushes 311a and 311b of the first cleaning body 311 are in a state of being pressed and in contact with the electrode surface 121 of the upper electrode 12 and the sample passage hole 12a. Furthermore, the coupling body 33 is connected to a suction port 102 </ b> A provided in the frame body 102 of the base 101.

  At this time, dust generated in the upper electrode 12 is sucked from the opening on the upper electrode 12 side, passes through the intake passage 31A of the arm portion 31, and is discharged to the outside from the suction port 102A.

  Next, the lower electrode 11 is raised by the lower electrode lifting mechanism 15. At this time, the peripheral part of the electrode surface 111 of the lower electrode 11 is in contact with the side wall 314 provided around the second cleaning body 312 (FIG. 10C). Also, the brushes 312 a and 312 b of the second cleaning body 312. Is a state in which the electrode surface 111 of the lower electrode 11 and the periphery thereof are in press contact.

  At this time, dust generated in the lower electrode 11 passes through the intake passage 314A provided in the side wall 314 and the intake passage 31A of the arm portion 31 and is discharged to the outside from the suction port 102A.

  After cleaning, the lower electrode 11 is lowered, and then the arm portion 31 is lowered to the facing position R1 by the installation portion raising / lowering mechanism 24, and further rotated to the retreat position R2 by the rotation driving mechanism 32. And when analyzing a some sample continuously, it transfers to a crucible supply stage again.

  In the operation of the transport / cleaning unit 3 described above, in the present embodiment, the rotation drive mechanism 32 mounts the arm part 31 gripping the crucible R by the gripping claws 313 in order to place the crucible R on the lower electrode 11. The mounting position R4 is made different on the lower electrode 11 every time it is moved to the mounting position R4. That is, the position where the crucible R is placed on the lower electrode 11 is made different for each analysis. For example, for each analysis, the position where the crucible R is placed on the lower electrode 11 is changed by about 0.5 mm.

  Specifically, the control device rotates the arm portion 31 to the mounting position R4 in order to place the crucible R on the lower electrode 11 with a drive pulse output to the stepping motor that is the actuator 323 of the rotation drive mechanism 32. Each time it is moved, it is set differently. More specifically, in each analysis, every time the arm portion 31 holding the crucible R by the holding claw 313 is moved to the mounting position R4, the pulse amount of the drive pulse is set to be different by several pulses and set randomly. . If this is the case, it is possible to solve the problem that the lower electrode 11 and the upper electrode 12 are worn only in the same portion, and it is possible to extend the lifetime of the lower electrode 11 and the upper electrode 12.

  <Effect of this embodiment>

  According to the elemental analysis device 100 according to the present embodiment configured as described above, the arm unit 31 including the cleaning bodies 311 and 312 for cleaning the upper electrode 12 and the lower electrode 11 and the gripping claws 313 for gripping the crucible R is provided. Since it is rotated and moved to each of the facing position R1, the gripping position R3, the mounting position R4, the discarding position R5, and the retracting position R2, the crucible is transported, discarded, and the electrode is cleaned. It can be automated by one mechanism, and the elemental analyzer 100 can be miniaturized.

  Further, since a stepping motor is used as the actuator 323 of the rotational drive mechanism 32, the increase and decrease of each stop position of the arm portion 31 and the fine adjustment of each stop position can be easily performed, and the maintainability of the element analyzer 100 can be improved. In addition, it is possible to improve the usability of the elemental analyzer 100 and the position accuracy of the placement position R4 of the crucible R and the like.

  <Other modified embodiments>

  The present invention is not limited to the above embodiment. In the following description, the same reference numerals are given to members corresponding to the above-described embodiment.

  For example, an actuator that can be stopped at a plurality of rotational positions, such as a servo motor or a rotating air cylinder, can be used as the actuator of the rotational drive mechanism in addition to the stepping motor. Further, the rotational drive mechanism may be configured to convert the reciprocating motion of the direct acting air cylinder into a rotational motion and rotate the rotating shaft.

  In the above-described embodiment, the arm portion at the facing position is moved up and down by the installation unit lifting mechanism, but a dedicated lifting mechanism different from the installation unit lifting mechanism may be provided.

  In addition, some or all of the above-described embodiments and modified embodiments may be combined as appropriate, and the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. .

The typical block diagram of the elemental analyzer which concerns on one Embodiment of this invention. The schematic block diagram of a crucible supply mechanism. Sectional drawing which mainly shows an electrode part and a conveyance / cleaning unit. The figure which shows each stop position of an arm part. The schematic diagram which shows retraction position R2 of an arm part. The schematic diagram which shows the holding position R3 of an arm part. The schematic diagram which shows mounting position R4 of an arm part. The schematic diagram which shows the discard position R5 of an arm part. The schematic diagram which shows the opposing position R1 of an arm part. The schematic diagram which shows a cleaning stage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Element analyzer R ... Crucible 12 ... Upper electrode 11 ... Lower electrode 23 ... Crucible installation part 3 ... Conveying / cleaning unit 31 ... Arm parts 311, 312, ...・ Cleaning body (first cleaning body, second cleaning body)
313: Grasping part 32 ... Rotation drive mechanism 322 ... Rotating axis R1 ... Opposite position R2 ... Retraction position R4 ... Placement position

Claims (2)

The upper and lower electrodes, a crucible for containing a sample is sandwiched, by applying a voltage to the electrodes, and heating the crucible, an elemental analyzer for analyzing the elemental of the sample from the thereby producing gas There,
While transporting the crucible on the lower electrode from the crucible installation part where the crucible is installed, the transport / cleaning unit for cleaning the upper electrode or the lower electrode,
The transport / cleaning unit is
A cleaning body for cleaning the upper electrode or the lower electrode, and an arm unit having a gripping part for gripping a crucible installed in the crucible installation part;
The arm portion is supported by a rotation shaft, and the cleaning body is opposed to the upper electrode or the lower electrode, the mounting position where the crucible gripped by the gripping portion is mounted on the lower electrode, and the facing position An elemental analysis apparatus comprising: a rotary drive mechanism that rotationally moves and stops the arm unit at each retreat position separated from the mounting position.   Each time the rotational driving mechanism moves the crucible on the lower electrode, the placement position changes each time the arm portion is moved to the placement position, so that the crucible position on the lower electrode is different. The elemental analysis apparatus according to claim 1.