JP4299212B2 - Particle size distribution measuring device - Google Patents

Description

  In the present invention, the particle group dispersed in the cell is irradiated with light, and the particle size distribution of the particle group based on the intensity distribution of diffraction and / or scattered light (hereinafter referred to as diffraction scattered light) generated at that time. The present invention relates to a so-called diffraction / scattering type particle size distribution measuring apparatus for measuring the above.

  There are a plurality of types of cells used in this type of particle size distribution measuring apparatus for each measurement method, and representative examples thereof include batch cells, wet flow cells, and dry cells. Conventionally, in a particle size distribution measuring apparatus, usually only one cell is held exchangeably in a cell holder screwed to the apparatus main body.

  However, in order to replace the cell with a different type, the cell holder must be replaced, and when replacing the cell holder, the cell holder can be taken out of the main body by loosening or unscrewing the cell holder, or the cell can be accommodated. It is necessary to fix the cell holder used for the measurement again with screws after being retracted in the sample chamber so that it does not get in the way, which requires considerable work. In particular, a wet flow type cell holder is connected by a pipe with a pretreatment mechanism such as an ultrasonic probe for dispersion, a stirring blade, a circulation pump, etc., which is arranged at a different location in the apparatus body. When removing it, it is necessary to remove the pipe and remove the screw that fixes the cell holder to the apparatus, which is very troublesome.

  On the other hand, as shown in Patent Document 1, a flexible material such as a silicon tube or a tube that can be bent or stretched is used for the pipe, and the cell holder is held in the sample chamber while the pipe and the cell holder are connected. Some are designed to be evacuated to a position that does not. However, since other types of cell holders (dry type cell holders, batch type cell holders, etc.) need to be taken out of the apparatus main body when not needed, it is also necessary to remove the fixing screw to the apparatus main body when replacing the cell holder. . Thus, a lot of labor is required when exchanging cells, particularly when exchanging with a different type of cell.

  Under such circumstances, a plurality of different types of cells are detachably fixed directly or via a cell holder to a single cell holding member, and the cell holding member is moved to save labor. Attempts have been made.

However, if a plurality of cells are placed on one cell holding member and moved, difficulty arises due to the problem of cell position reproducibility. For example, if the position of the cell holding member is different for each movement during measurement, the measurement result is affected. There is a risk of giving.
JP 2002-243622 A

  Accordingly, the present invention has been made to solve the above-mentioned problems all at once, and in this type of particle size distribution measuring apparatus, it saves the work required for cell replacement and ensures cell position reproducibility. Is the intended task.

  That is, the particle size distribution measuring apparatus according to the present invention includes a light source that irradiates light in a certain direction, a plurality of cells that contain a group of particles, a light irradiation position at which the light is irradiated, and the light irradiation position. Is a cell holding mechanism that is slidably held between retraction positions set at different positions, and the particle group based on the light intensity of diffracted scattered light generated from the particle group accommodated in the cell at the light irradiation position The cell holding mechanism includes a rail member extending along a moving direction of the cell, a cell mounting member for mounting each cell, and a narrower member. A holding body and an elastic member disposed between the cell mounting member and the holding body, and a first contact surface provided on the cell mounting member and a second contact surface provided on the holding body. Arranged at the opposite position across the rail member As well as, the attracting said contact faces by elastic restoring force of the elastic member with each other, which is constituted them contact surface so as to be movable in pressure contact with the rail member.

  If this is the case, the cell can be exchanged for a different type of cell by simply moving it forward and backward with the cell holding mechanism, so the time required to change the measurement can be shortened and the burden on the operator can be reduced. Can do. Furthermore, since the cell mounting member is pressed against the rail member, the cell position reproducibility can be ensured. For example, it is possible to prevent a positional shift from occurring every movement, and to ensure measurement accuracy.

  Here, the replacement of cells includes not only switching to a different type of cell but also switching to a different cell of the same type.

  In order for the operator to accurately and easily move a desired cell to the light irradiation position, a fitting hole provided in one of the rail member and the cell mounting member, and a fitting pin provided in the other, And further comprising a positioning mechanism for defining the light irradiation position of each cell by fitting the first contact surface to the upward surface of the rail member with the first contact surface as a downward surface, and the second contact surface In such a manner that one of the cell mounting members on the moving direction side can be lifted and inclined against the elastic force of the elastic body. It is desirable that the fitting is released and the cell mounting member can be slid.

  In order to allow an operator to move the cell holding mechanism more easily, it is desirable to provide a handle at one end of the cell mounting member.

  In order to reduce the force required for movement by the cell holding mechanism, it is desirable that at least one of the contact surfaces is an outer peripheral surface of the rolling element.

  In order to ensure measurement accuracy so that the cell mounting member does not move left and right on the rail member, the rail member has a guide surface parallel to the moving direction, and the cell mounting member is placed on the guide surface. It is desirable to further include a pressing member that has a guided surface that comes into contact, and that presses and contacts the guiding surface and the guided surface.

  Specifically, the pressing member is a second elastic member provided between the cell mounting member and the rail member, and the guided surface is slidably pressed against the guiding surface by the elastic return force. It is desirable to configure.

  As described above, according to the present invention, since the cell can be replaced with a different type of cell simply by moving forward and backward by the cell holding unit mechanism, the time required to change the measurement can be shortened and the burden on the operator can be reduced. Can be achieved. Furthermore, since the cell mounting member is pressed against the rail member, the cell position reproducibility can be ensured. Therefore, for example, it is possible to prevent a positional deviation from occurring every movement, and to ensure measurement accuracy.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the particle size distribution measuring apparatus 1 according to the present embodiment, the scattering pattern of the diffracted scattered light LS (angular distribution of diffracted scattered light intensity) generated when the particle group S is irradiated with the irradiation light L is determined by the particle diameter. The particle size distribution is measured from the MIE scattering theory by using and detecting the scattering pattern. A schematic overview of the particle size distribution measuring apparatus 1 is shown in FIGS. In the figure, reference numerals C1 and C2 denote cells that contain samples in which the measurement target particle group S is dispersed in a dispersion medium. The dispersion medium is generally water in the case of wet and air in the case of dry. Reference numeral 2 denotes a light source that irradiates the cells C1 and C2 with irradiation light L. In this embodiment, for example, a semiconductor laser that emits coherent laser light is used as the light source. Reference numerals 31 and 32 are photodetectors arranged around the cells C1 and C2. Then, the light intensity of the diffraction scattered light LS generated from the particle group S irradiated with the light L is detected. Reference numeral 4 denotes a signal processing unit configured by a buffer, an amplifier, and the like that receive the diffraction scattered light intensity signals output from the photodetectors 31 and 32 and perform processing such as conversion. Reference numeral 5 denotes an arithmetic unit that calculates the particle size distribution of the particle group S based on the value of each scattering intensity signal processed by the signal processing unit 4. Reference numeral 6 denotes a convex lens that is set so that the transmitted light L converges at the center of the light receiving surface of the photodetector 32.

  The cell C1 is of a wet flow type, and as shown in FIG. 2, the upper and lower sides are held by the cell mounting member 72 with a wet cell holder C1h. The cell holder C1h includes an attachment portion C1h1 for inserting the cell C1 and a lid portion C1h2 for fixing the cell C1 by a latch mechanism C1h3 using a coil spring. The lid C1h2 is provided with an introduction port for introducing the sample solution. The cell C1 is provided on a liquid circulation channel together with a particle agitation device such as a circulation pump and an ultrasonic probe (not shown) in order to disperse the particle group S in a liquid solvent such as water. In the figure, reference numerals C1a and C1b form the liquid circulation flow paths and are pipes C1a and C1b respectively connected to the lead-in / out ports of the cell C1.

  The cell C2 is a so-called batch type that is suitably used when measuring a small amount of sample. As shown in FIG. 2, the lower part of the cell C2 is held on the cell mounting member 72 by a batch type cell holder C2h.

  In this embodiment, as shown in FIGS. 3 and 6, a plurality of different types of cells C1 and C2 are crossed with the optical axis 12 in the front-rear direction (through direction of the cell storage chamber (orthogonal) in a cell storage chamber (not shown). A cell holding mechanism 7 that holds the cell C1 and C2 selectively at a light irradiation position P to which the light L from the light source 2 is irradiated. A tray 8 on which the cell holding mechanism 7 is mounted is provided.

  As shown in FIG. 3, the cell holding mechanism 7 includes a rail member 71 extending in the front-rear direction, a cell mounting member 72 for mounting the cells C1 and C2, a holding member 73, and the cell mounting member. 72 and an elastic member 74 disposed between the holding member 73, and the rail member 71 is sandwiched between the cell mounting member 72 and the holding member 73 by the tensile force of the elastic member 74. The cell mounting member 72 is configured to move forward and backward along the line.

  More specifically, the rail member 71 includes a pair of parallel rail elements 711 disposed on the floor surface of the cell storage chamber along a track 10 (FIG. 2) orthogonal to the optical axis 12. Reference numeral 711 includes an upright plate 712 that stands vertically from a bottom plate 81 of the tray 8 described later, and a horizontal plate 713 that is attached to the upper surface of the upright plate 712.

  The cell mounting member 72 has a rectangular plate shape and is disposed on the horizontal plate 713 of the rail member 71. The cells C1 and C2 are held on the upper surface of the cell mounting member 72 in a line along the front-rear direction (back and forth direction). Each of the cells C1 and C2 is detachably attached to the cell mounting member 72 directly or via the cell holders C1h and C2h, and is held obliquely with a predetermined angle such as a Brewster angle with respect to the optical axis 12. This is to reduce the influence of reflection on the surfaces of the cells C1 and C2. A handle 721 is provided at least at the front end of the cell mounting member 72 to facilitate movement. Further, as shown in FIGS. 2 and 8, the rear end portion 724 of the cell mounting member 72 is processed into an arc shape so as to easily slide on the rail member 71.

  The sandwiching body 73 has a box-shaped sandwiching body main body 731 having an open upper surface, and a horizontal shaft 731a extending laterally (in a direction perpendicular to the cell advance / retreat direction) to the outside of the upper end of the side plate of the sandwiching body main body 731 And a disk-shaped rolling element 732 attached rotatably. The rolling elements 732 are provided on the left and right sides of the front and rear portions, respectively, and are disposed below the horizontal plate 713 of the rail member 71.

  The elastic member 74 is a tension coil spring provided between the holding body 73 and the cell mounting member 72, and its lower end is attached to a horizontal shaft 733 spanned between the side plates of the holding body 73, and the cell The upper end is attached to a locking portion 723 provided on the mounting member 72 to attract the holding body 73 and the cell mounting member 72 in the vertical direction. In this embodiment, two tension coil springs are provided at the rear and two at the front. The rear tension coil spring 74 is disposed inside the rear rolling element 732 and at substantially the same position in the front-rear direction. The front tension coil spring 74 is disposed on the front side of the front rolling element 732. Then, due to the pulling force of these elastic members 74, the first contact surface 72a (specifically, the lower surface of the side edge) provided on the cell mounting member 72 and the second contact surface 732a (specifically, provided on the holding member 73). Specifically, the outer peripheral surface of the rolling element 732 is in press contact with each horizontal plate 713 of the rail member 31 so as to be movable from above and below.

  The cell holding mechanism 7 includes a positioning mechanism 75 that defines the cells C1 and C2 at the light irradiation position P. The positioning mechanism 75 includes a plurality of fitting holes 751 provided in one of the rail member 71 and the cell mounting member 72 (here, the horizontal plate 713 of the rail member 71), and the other (here Then, a fitting pin 752 provided on the lower surface of the cell mounting member 72 is provided. By fitting the fitting pin 752 into one of the fitting holes 751, the one of the cells C1, C2 can be selectively disposed at the light irradiation position P. The cell mounting member 72 is moved in a state in which the handle 721 on the front side of the cell mounting member 72 is lifted upward to be inclined and the fitting between the fitting hole 751 and the fitting pin 752 is released.

  The cell holding mechanism 7 further includes a left / right movement suppression mechanism 76 that prohibits movement of the cell mounting member 72 in the left / right direction. The left / right movement restraining mechanism 76 has a guide surface 76a (specifically, a contact plate 714 raised from the outer surface of one rail element 711) parallel to the front / rear direction (cell advance / retreat direction) provided on the rail member 71. The lateral movement of the cell mounting member 72 is suppressed by pressing the guided surface 76b (specifically, one outer surface of the cell mounting member 72) provided on the cell mounting member 72 against the side surface by the pressing member 761. For this purpose, a second elastic member 761 is provided between the cell mounting member 72 and the rail member 71 as a pressing member 761 for applying an elastic return force in the left-right direction. The second elastic member 761 is a leaf spring provided on the support plate 722 suspended from the lower surface of the side edge portion of the cell mounting member 72, for example. The leaf spring 761 presses the inner surface of the other upright plate 712 in the rail member 71 and presses one outer surface 76b of the cell mounting member 72 against the inner surface 76a of the contact plate 714 by the reaction force.

  The cell holding mechanism 7 is mounted and fixed on a tray 8 fixed in the cell storage chamber. As shown in FIGS. 6 and 7, the tray 8 has a bottom plate 81 on which the cell holding mechanism 7 is placed, a left and right side plate 82, and a rear plate 83. In addition, a lower portion of the front edge is further provided with a flange 85 extending left and right. The tray 8 receives sample liquid that has been accidentally spilled when the cells C1 and C2 are replaced. The sample liquid spilled on the tray 8 travels along the bowl 85 and has a discharge port 85a provided at the end thereof. Then, it is guided to the circulation tray below and finally discharged from the drain of the circulation tray to the outside.

  Next, an example of a particle size distribution measurement procedure using the apparatus 1 will be described below.

  First, the operator slides on the rail member 71 in a state where the positioning mechanism 75 is released by lifting the handle 721 at the front end of the cell mounting member 72 (FIG. 7), and a desired cell (for example, C1) is irradiated with the light irradiation position. Move to P. This state is the state shown in FIG. At this time, since the rear end portion 724 of the cell mounting member 72 is processed into an arc shape, the cells C1 and C2 can be moved smoothly. Further, whether or not the cell C1 exists at the light irradiation position P can be determined by a click stop feeling of the positioning mechanism 75 provided on the cell mounting member 72 and the rail member 71. Then, cell identification means (not shown) identifies the cell and outputs a cell identification signal to the arithmetic unit 5. The arithmetic unit 5 receives the output cell identification signal, selects a program corresponding to the cell C1, and starts it. Then, the arithmetic unit 5 displays a condition setting screen based on the selected program, and sets (changes) the processing conditions and the like. Then, if measurement is started as usual, the particle size distribution of the particle group S accommodated in the cell C1 is obtained.

  When measuring the particle group S of another cell C1, the cell mounting member 72 may be slid as described above.

  Note that pipes C1a and C1b are connected to the cell C1, respectively. However, as described above, some or all of the pipes C1a and C1b have flexibility, so that they deform as the cell C1 moves. Therefore, it is easy to attach and detach, and does not hinder the movement of the cells C1 and C2 (movement of the cell mounting member 72).

  According to the present embodiment configured as described above, the plurality of cells C1 and C2 are configured to be switched by being moved forward and backward by the cell holding mechanism 7, thereby reducing the time required for changing the measurement. In addition, the burden on the operator can be reduced. In addition, it is possible to ensure the reproducibility of the positioning of the cell mounting member 72 on the rail member 71 in the vertical and horizontal directions on the rail member 71 and to suppress the vibration, so that the measurement accuracy can be improved.

  Moreover, since the positioning mechanism 75 is provided and each cell C1, C2 can be positioned reliably and easily at the light irradiation position P, the measurement accuracy can be improved.

  Further, since the handle 721 is provided, the operator's work can be facilitated.

  In addition to the above, in the present embodiment, since the second contact surface is the outer peripheral surface of the rolling element, the cell mounting member 72 and the sandwiching body 73 can be moved smoothly. Therefore, the burden on the operator can be reduced, and the time required for measurement preparation can be shortened.

  In addition, the rail member 71 has a guide surface 76a parallel to the moving direction. The elastic force of the leaf spring 761 provided between the cell mounting member 72 and the rail member 71 causes the cell mounting member 72 to move. Since the provided guided surface 76b is configured so as to be slidably pressed against the guide surface 76a, the cell mounting member 72 can be prevented from vibrating left and right on the rail member 71, and the particle size distribution can be reduced. Measurement accuracy can be increased.

  The specific configuration of each part is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the pressing member is a leaf spring provided between the cell mounting member and the rail member. However, the pressing member is not limited to this, and any member that presses the guided surface against the guiding surface may be used. Therefore, for example, one or a plurality of bars for pressing the sandwiching body (or cell mounting member) may be provided on the rail member.

  In addition, the positioning mechanism does not have to be composed of a fitting hole and a fitting pin, and may be anything as long as it uses a latch mechanism.

  Furthermore, the rear end portion of the cell mounting member may not be processed into an arc shape, and a bearing may be provided at the rear end portion to facilitate sliding movement. Alternatively, the rear end portion may be made of a slippery material.

  In the embodiment, the particle size distribution measuring apparatus using the wet flow cell and the batch type cell is shown. However, the combination of the cells is not limited to these, and for example, two wet flow cells may be used. Or what used two kinds, a wet flow cell and a batch type cell, may be used.

  In the above embodiment, the cell identification means automatically identifies the cell, and the particle size distribution measuring device automatically changes the measurement screen or measurement condition corresponding to the cell. You may make it.

1 is a schematic overall view showing a configuration of a particle size distribution measuring apparatus according to an embodiment of the present invention. The perspective view which showed the cell holding | maintenance mechanism vicinity in the same embodiment. The typical sectional view of the cell holding mechanism in the embodiment. The schematic diagram which shows the cell mounting member and clamping body in the embodiment. The schematic diagram which shows the cell mounting member and clamping body in the embodiment. The schematic diagram which shows the cell holding mechanism and tray in the same embodiment. The schematic diagram which shows the rail member and tray in the embodiment. The enlarged view of the rear-end part of the cell mounting member in the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Particle size distribution measuring apparatus C1, C2 ... Cell L ... Light LS ... Diffraction and / or scattered light P ... Light irradiation position 2 ... Light source 31, 32 ... Light Detector 5 ... arithmetic device 7 ... cell holding mechanism 71 ... rail member 72 ... cell mounting member 73 ... clamping body 74 ... elastic member 75 ... positioning mechanism 751 ... Fitting hole 752 ... fitting pin 721 ... handle 732 ... rolling element 761 ... second elastic member (leaf spring)
76a ... Guide surface 76b ... Guide surface

Claims (6)

A light source that emits light in a certain direction, a plurality of cells that contain particles, and a light irradiation position where the light is irradiated and a retreat position that is set to a position different from the light irradiation position The particle group based on the light holding intensity of the cell holding mechanism that holds the movable body and the diffracted light and / or scattered light (hereinafter referred to as diffracted scattered light) generated from the particle group accommodated in the cell at the light irradiation position. An arithmetic device for calculating the particle size distribution of
The cell holding mechanism includes a rail member extending along the moving direction of the cell, a cell mounting member for mounting each cell, a holding member, and an elastic member disposed between the cell mounting member and the holding member. The first contact surface provided on the cell mounting member and the second contact surface provided on the holding body are arranged at positions facing each other with the rail member interposed therebetween, and the elastic member A particle size distribution measuring apparatus characterized in that the contact surfaces are attracted to each other by an elastic restoring force, and the contact surfaces are movably pressed into contact with the rail member. It further includes a positioning mechanism that defines the light irradiation position of each cell by fitting a fitting hole provided in one of the rail member and the cell mounting member and a fitting pin provided in the other. And
The first mounting surface is brought into contact with the upward surface of the rail member as a downward surface, and the second contact surface is brought into contact with the downward surface of the rail member as the upward surface, so that the cell mounting member moves in the moving direction. 2. The grain according to claim 1, wherein one of the two is configured to be lifted and inclined against the elastic force of the elastic body, and the fitting is released and the cell mounting member can be slid in the inclined state. Diameter distribution measuring device.   The particle size distribution measuring apparatus according to claim 2, wherein a handle is provided on a lifting side of the cell mounting member.   4. The particle size distribution measuring apparatus according to claim 1, wherein at least one of the contact surfaces is an outer peripheral surface of a rolling element. The rail member has a guide surface parallel to the moving direction, and the cell mounting member has a guided surface in contact with the guide surface;
The particle size distribution measuring apparatus according to claim 1, 2, 3, or 4, further comprising a pressing member that presses and contacts the guide surface and the guided surface. The pressing member is a second elastic member provided between the cell mounting member and the rail member, and is configured so that the guided surface is slidably pressed against the guiding surface by its elastic restoring force. The particle size distribution measuring apparatus according to claim 5 .