JP3422701B2 - Flow cell holder for particle size distribution analyzer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow cell holder of a particle size distribution measuring device for supporting a flow cell in which a sample solution in which a particle group is dispersed in a dispersion medium flows.

[0002]

2. Description of the Related Art In a particle size distribution measuring device utilizing the diffraction or scattering phenomenon of light by particles, the intensity distribution of diffracted light or scattered light generated by irradiating dispersed sample particles with, for example, laser light The particle size distribution of the sample particles is calculated by measuring the relationship between the bending angle or the scattering angle and the light intensity with a plurality of sensor elements and performing arithmetic processing based on the Fraunhofer diffraction or Mie scattering theory.

The particle size distribution measuring device is, for example, as shown in FIG.
The configuration is as shown in. In the figure, reference numeral 1 is a dispersion bath, inside of which a stirring blade 3 rotated by a motor 2 is provided, and outside of a bottom surface 4 an ultrasonic transducer 5 vibrated by an oscillator (not shown) is provided. ing. 6 is a tank containing a dispersion medium 7 containing sample particles, 8 is a dispersion medium supply pipe, which is provided with an opening / closing valve 9 such as an electromagnetic valve, and is openly connected to the opening of the dispersion bath 1.

Reference numeral 10 denotes a square tube-shaped glass flow cell filled with a suspension, the thickness of which is precisely processed, and the dispersion bath 1 is a circulation flow path provided with a pump 11 and a switching valve 12. They are connected by 13 and together form a suspension circulation system 14. Reference numeral 15 is a laser light source provided on one side of the flow cell 10, 16 is a condenser lens provided on the other side of the flow cell 10, and a detector 17 is provided at a focus position behind the condenser lens. The intensity distribution of scattered light is measured.

The flow cell holder 18 of the conventional flow cell 10 has a structure as shown in FIG. 6, for example. In the figure, 19 is a base, and base 1
A step portion 20 is formed at the rear end of the upper surface of 9, and through holes 21 are formed on both side portions of the step portion 20. Reference numeral 22 denotes a lower holder provided on the lower side of the cell 10, and the flow cell 1 is provided on the upper surface.
A contact portion 23 with which the lower surface opening 10a of 0 abuts is formed,
An annular O-ring groove 24 is formed on the periphery of the O-ring groove 24.
The O-ring 25 is fitted into the ring groove 24, and the contact portion 2
Two through holes 26 are provided side by side on both sides of the lower holder 2
The introduction pipe 27 connected to the second introduction hole (not shown) is drawn out forward. Reference numeral 28 denotes side holders provided on both the left and right sides of the cell 10, and grooves 29 with which both side portions of the cell 10 contact are precisely machined on the side surface, and two screw holes 30 are provided at the upper and lower portions of the side holder 28. Are formed. Reference numeral 31 denotes an upper holder provided on the upper side of the cell 10, and a contact portion (not shown) with which the upper surface opening 10b of the cell 10 abuts is formed on the lower surface, and like the lower holder 22, a peripheral portion of the contact portion. An O-ring groove (not shown) is formed.
An O-ring 25 is fitted in the ring groove, two through holes 26 are arranged in parallel on both sides of the contact portion, and a discharge pipe 32 connected to a discharge hole (not shown) of the upper holder 31 is led out forward. The introduction pipe 27 and the discharge pipe 32.
Are connected to the circulation channel 13.

When the cell 10 is attached to the holder 18, the peripheral edge of the lower surface opening 10a of the cell 10 is brought into contact with the contact portion 23 of the lower holder 22, and the grooves 29 of the side holders 28 are formed on both sides of the cell 10. Abut, and fix the cell fixing screws 33a to the through holes 26 of the lower holder 22 by the spring washers 33.
Inserted through b, screwed into the screw holes 30 of both side holders 28, the O-ring 25 is pressed against the peripheral edge of the lower surface opening 10a of the cell 10, and the cell 10 and both side holders 28 are attached to the upper surface of the lower holder 22. Then, the contact portion of the upper holder 31 is brought into contact with the peripheral portion of the upper surface opening 10b of the cell 10, and the cell fixing screw 33a is inserted into each through hole 26 of the upper holder 31 via the spring washer 33b. Then, the screw holes 3 of the both side holders 28
0 and screw the O-ring 25 to the top opening 10b of the cell 10.
The upper holder 31 is attached to the upper surfaces of both side holders 28 by pressure contact with the peripheral edges of
The peripheral edge of the cell is hermetically sealed, and the cell 10 is attached to the prescribed position with high accuracy. Then, the holder 18 is used as the base 1
The holder fixing screw 33c is inserted into the through hole 21 of the base 19 and the through hole 26 of the lower holder 22 and screwed into the screw holes 30 in the lower portions of both side holders. The holder 18 is attached to.

[0007]

In the case of the conventional flow cell holder 18, when the flow cell 10 is attached,
Since a plurality of cell fixing screws 33a are used, it is difficult to attach the cell 10 to the cell holder 18 and remove it from the cell holder 18, and further, when performing maintenance on the flow cell 10, fixing all cells. Since it is necessary to remove the screws 33a from the lower holder 22, the upper holder 31, and both side holders 28, the work is complicated,
There is a problem that it takes a lot of time. Also, the cell 10
Even if the thickness of the cell 10 and the groove 29 of both side holders 28 are precisely machined, the thickness of the cell 10 and the groove 29 of both side holders 28 are
A gap is generated between the cells 10 and, and the cell 10 rattles due to this gap. Moreover, if both side holders 28 are attached to the lower holder 22 with a slight left or right displacement, or if the positions of the processed left and right grooves 29 are slightly displaced, the cell 1
There is a risk that 0 will be twisted and cracked. Furthermore, if it is attempted to avoid the rattling of the cell 10 and both side holders 28 and the cracking of the cell 10, there is a problem that more precise processing is required.

The present invention has been made in view of the above points, and an object thereof is to facilitate attachment and detachment of a flow cell to and from a cell holder,
Improves workability when performing cell maintenance, and prevents rattling, cracking, and distortion of the cell due to cell and holder mounting errors and processing errors, making the cell simple and
It is an object of the present invention to provide a flow cell holder for a particle size distribution measuring device, which can be mounted in a precise position with high accuracy.

[0009]

In order to solve the above problems, a flow cell holder of a particle size distribution measuring apparatus according to claim 1 supports a flow cell in which a sample liquid in which particle groups are dispersed in a dispersion medium flows. A support surface formed on the flow cell holder for supporting the cell so as to be perpendicular to an optical axis connecting a light source provided on one side of the cell and a detector provided on the other side of the cell; And a pressing means for pressing one surface of the cell such that the other surface of the cell is in pressure contact with the supporting surface.

Therefore, the flow cell holder is provided with a support surface for supporting the cell so that the cell is perpendicular to the optical axis connecting the light source provided on one side of the cell and the detector provided on the other side, and the pressing means is formed. Since one surface of the cell is pressed by pressing the other surface of the cell against the supporting surface,
In addition, it can be installed in a precise and accurate position.

Moreover, since the cell is not attached to the side holder as in the conventional case, a gap is not formed between the cell and the holder, and the cell does not rattle. Further, there is no crack or distortion of the cell due to the mounting error of the cell and the holder or the processing error.

Further, in the flow cell holder according to claim 2, a lower holder in which a lower end portion of a flow cell in which a sample liquid in which a particle group is dispersed in a dispersion medium flows is inserted into a lower concave portion, and a bottom surface and a side wall of the lower concave portion. And a supporting surface for supporting the cell so as to be perpendicular to an optical axis connecting a light source provided on one side of the cell and a detector provided on the other side of the cell, and the lower holder. A pipe connected to a hole for introducing or discharging the sample liquid, an upper holder for inserting the upper end of the cell into an upper recess and supporting the upper end, and a pipe for connecting the upper holder to the sample liquid. A pipe for discharging or introducing water, an O-ring that is provided in each of the recesses and seals the peripheral portions of the upper surface opening and the lower surface opening of the cell, and project from both side surfaces of one end of the upper holder. Located parallel to the axis A support plate in which a pin and a horizontal support piece are mounted on both side surfaces of the lower holder, and a tip end of a vertical bending piece extending from one end of the support piece is located at one end of the upper holder. A pressing bolt that is screwed onto the supporting piece and presses one surface of the cell so that the other surface of the cell is in pressure contact with the supporting surface; and a pin that is formed at the tip of the bent piece and that the pin is inserted. And a tension spring having one end locked to one end of the support piece and the other end locked to the pin inserted into the long hole, and the other end of the upper holder, It is provided with a mounting bolt screwed to the lower holder and a compression spring provided between the other end of the upper holder and the mounting bolt.

Therefore, the lower end of the flow cell is inserted into the lower recess of the lower holder, and the optical axis connecting the light source provided on one side of the cell and the detector provided on the other side of the cell on the bottom surface and side wall of the lower recess. A support surface is formed so that the cell is perpendicular to the upper holder, the upper end of the flow cell is inserted into the upper recess of the upper holder, and the pins positioned parallel to the optical axis are attached to both side surfaces of one end of the upper holder. The support pieces of the support plate are mounted on both sides of the lower holder.Pressing bolts that press one surface of the cell are screwed into the support piece, and the other surface of the cell is pressed against the support surface to fold the support plate. Insert the pin into the long hole of the bent piece, lock one end of the tension spring to one end of the support piece of the support plate, and lock the other end to the pin inserted into the long hole. Insert the mounting bolt, which has a compression spring between it and the end, through the other end of the upper holder and Because it is screwed into da, simple cell, and can be attached to accurately correct position. Also, when the cell is attached to the cell holder, the compression spring of the attachment bolt is compressed, and at the same time, one end of the upper holder is pulled downward by the tension spring via the pin, and the lower recess is surrounded by the lower edge of the cell. The portions are pressed together, and the peripheral portions of the upper opening of the cell are pressed against the upper concave portion, so that the peripheral portions of the both openings can be reliably sealed. Moreover, it is not necessary to increase the dimensional accuracy of the upper holder and the lower holder, and liquid leakage from the both openings of the cell due to dimensional accuracy error and distortion and cracking of the cell due to pressure contact between the upper holder and the lower holder do not occur.

Further, when removing the cell from the cell holder, it is sufficient to remove the mounting bolt from the lower holder and loosen the pressing bolt, and the cell can be easily taken out from the lower recess of the lower holder, and maintenance can be easily performed. .

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION FIG.
Will be described with reference to. In these drawings, 34 is a cell holder, which is mainly composed of a lower holder 3 having an L-shaped cross section.
5 and a rectangular parallelepiped upper holder 43.

The lower holder 35 is a horizontal base body 35.
a and a ridge 35b integrally formed on one side of the upper surface of the base body 35a in the horizontal direction. A lower recess 35c is formed at the center of the ridge 35b, and the lower recess 35c has an outer surface. The precision machined lower end of the flow cell 10 is removably inserted, the lateral support surface X is precisely machined on the bottom surface of the lower recess 35c, and an annular O-ring groove 35d is formed on the lateral support surface X. The O-ring 35e is fitted in the O-ring groove 35d, and the peripheral edge of the lower surface opening of the cell 10 abuts on the O-ring 35e. Reference numeral 35f denotes a support member projectingly provided on the other side wall surface of the lower recess 35c, and has a vertically-supported vertical support surface Y. Reference numeral 37 denotes an introduction hole (or a discharge hole) formed from the base body 37a to the protrusion 37b. A communication hole 38 is formed between one end of the introduction hole 37 and the lower recess 35c, and the other end of the introduction hole 37 is formed. The introduction pipe 39 is connected to and led out to the other side, and the introduction pipe 39, the introduction hole 37, the communication hole 38, the lower recess 35c, and the lower surface opening of the cell 10 communicate with each other. 40
Is a cylindrical body integrally provided on the front end of the lower holder 35, and has a thread groove formed on the inner surface thereof.

Reference numeral 41 denotes two L-shaped support plates, each of which includes a horizontal support piece 41a and a vertical bending piece 41b extending from one end of the support piece 41a.
1a is attached to both side surfaces of the ridge 35b of the lower holder 35 by fixing bolts 42, a long hole 41c is formed at the tip of the bending piece 41b, and two pressing bolts 36 are provided on both sides of the supporting piece 41a. Penetrates and is screwed into a nut 36a fixed to the back surface of the support piece 41a, the tip end of the nut presses one surface of the lower end portion of the cell 10, and the lower surface of the cell 10 abuts the lateral support surface X. The other surface of the lower end of the cell 10 is in pressure contact with the vertical support surface Y, and the cell 10 is perpendicular to the optical axis connecting the light source provided on one side of the cell 10 and the detector provided on the other side of the cell 10. And the cell 10 is mounted in a precise position with high accuracy.

The upper holder 43 has an upper recess 43a formed at the center of the lower surface, and the upper end of the cell 10 is removably inserted into and supported by the upper recess 43a, and an annular shape is formed on the upper surface of the upper recess 43a. The O-ring groove 43b is formed, and the O-ring 43c is fitted into the O-ring groove 43b.
The peripheral edge of the upper surface opening of the cell 10 abuts on c. Reference numeral 44 denotes a discharge hole (or an introduction hole) formed in the upper holder 43, and the communication hole 4 is provided between one end of the discharge hole 44 and the upper recess 43a.
5, the discharge pipe 46 is connected to the other end of the discharge hole 44 and is led out to the other side.
4, the communication hole 45, the upper recess 43a, and the upper surface opening of the cell 10 communicate with each other. Reference numeral 47 denotes a pin projecting from both side surfaces of one end of the upper holder 43, which is positioned parallel to the optical axis, and the pin 47 is inserted into the long holes 41c of the bent pieces 41b of the both support plates 41. One end of the upper holder 43 is rotatably supported.

Reference numeral 48 denotes a tension spring, one end of which is engaged with the pin 48a of the support piece 41a of the both support plates 41 and the other end of which is engaged with the pin 47, so that one end of the upper holder 43 is vertically extended. I'm pulling. Reference numeral 49 denotes a notch formed in the other end of the upper holder 43. The notch 49 is provided with a mounting bolt 50. The tip of the mounting bolt 50 penetrates the bottom of the notch 49 and the other end of the upper holder 43. Has been derived from below. Reference numeral 51 denotes an annular stopper plate attached to the tip of the mounting bolt 50, which prevents the mounting bolt 50 from deviating from the upper holder 43. A compression spring 52 is provided between the bottom of the cutout 49 and the head of the mounting bolt 50, and the tip of the mounting bolt 50 is screwed into the cylinder 40 of the lower holder 35 and compressed.

The state of the solid line in FIG. 1 shows the state in which the cell 10 is attached to the cell holder 34, and the attachment bolt 50 is screwed into the tubular body 40 of the ridge 35b of the lower holder 35 and the upper holder 43. The pin 47 of the upper holder 43 is located on the upper end side of the elongated hole 41c.
8 is pulled vertically through the pin 47, the lower end of the cell 10 is inserted into the lower recess 35c of the protrusion 35b, and the lower surface of the lower end of the cell 10 contacts the lateral support surface X of the lower recess 35c. The pressing bolt 36 presses one surface of the lower end portion of the cell 10, the other surface of the lower end portion of the cell 10 is pressed against the vertical support surface Y of the support 35f, and the lower end portion of the cell 10 is connected to the horizontal support surface X and The cell 10 is supported by the vertical support surface Y, the upper end of the cell 10 is inserted into and supported by the upper recess 43a of the upper holder 43, and the cell 10 is supported perpendicularly to the optical axis.

From this state, the cell 10 is placed in the cell holder 34.
When removing from the ridge 35, loosen the mounting bolt 50.
While removing from the tubular body 40 of b, loosening the pressing bolt 36 to separate it from the one surface of the lower end portion of the cell 10, the upper holder 43 is rotated to the position shown by the chain line in FIG. The cell 10 and the holders 35 and 43 are cleaned upward by pulling them upward from the lower recess 35c. In this way, the cell 10 is placed in the cell holder 34
When removing from the upper holder 4 loosen the mounting bolt 50
It is only necessary to loosen the pressing bolt 36 while removing it from the connector 3, and unlike the conventional case, it is not necessary to remove all the plurality of screws to disassemble each holder, and maintenance can be easily performed.

When the cell 10 is attached to the cell holder 34, the lower end of the cell 10 is inserted into the lower recess 35a of the lower holder 35, and the peripheral edge of the lower surface opening of the cell 10 is brought into contact with the lateral support surface X and pressed. Tighten the bolt 36 to tighten the cell 10
One surface of the lower end of the cell 10 is pressed, and the other surface of the lower end of the cell 10 is pressed against the vertical support surface Y. Next, when the upper holder 43 is rotated against the tension spring 48 to the position shown by the solid line in FIG. 1, the upper end portion of the cell 10 is inserted into the upper recess 43a, and the peripheral edge portion of the upper surface opening of the cell 10 is raised. O-ring 43 of holder 43
abut on c. In this state, when the mounting bolt 50 is screwed into the cylindrical body 40 of the ridge 35b, the compression spring 52 is compressed, and at the same time, the tension spring 48 causes one end of the upper holder 43 to vertically pass through the pin 47. Is pulled in the direction, the peripheral portion of the lower surface opening of the cell 10 is pressed against the O-ring 35e of the lower recess 35c, and the O-ring 43c of the upper recess 43a is pressed.
The peripheral edge portion of the upper surface opening of the cell 10 is pressed against. That is,
Due to the stored force of both springs 48 and 52, both holders 3
The O-rings 35e and 43c of 5, 43 are pressed against the peripheral portions of both openings of the cell 10, respectively, and reliably seal the peripheral portions of the both openings.

As described above, in the case of the above-described embodiment, since the cell 10 is not attached to the side holder as shown in FIG. 6, a gap is not formed between the cell 10 and the holder and the cell 10 does not rattle. . Further, there is no crack or distortion of the cell 10 due to an attachment error or a processing error of the cell 10 and the holder. Moreover, unlike the conventional case, since the upper holder 43 and the lower holder 35 are not attached to the side holders, it is not necessary to improve the dimensional accuracy of these parts, and the cell 10 due to an error in the dimensional accuracy is not required.
There is no liquid leakage from the both openings, and the cell 10 is not distorted or broken by the pressure contact between the upper holder 43 and the lower holder 35.

In the above embodiment, the pressing bolt 36 is used as the pressing means of the cell 10, but the present invention is not limited to this, a spring plate may be used, and a pressing body 53 as shown in FIG. 4 may be used. Good. In this pressing body 53, the two tubular bodies 54 are
1a is inserted into the through holes 41d on both sides from the inside,
The flange 56 of the tubular body 54 abuts on the peripheral portions of both the through holes 41d, and the opening end portion on one side is closed by the lid plate 55.
An annular stopper plate 57 is screwed onto the peripheral surface of 4, and the cylindrical body 54 is attached to the support piece 41a. The diameter of the opening end on the other side of the tubular body 54 is slightly smaller than the diameter of the opening end on the one side. Inside the tubular body 54, a spring 58 is provided and the spring 58 causes the spring 58 to project. A ball 59 urged in the direction is provided at an open end of the other side of the tubular body 54 so as to be retractable and retractable, and a part of the ball 59 projects from the open end of the other side of the tubular body 54. Then, the lower end of the cell 10 is attached to the lower holder 3
5, when inserted into the lower recess 35c of the cell 10, one surface of the lower end portion of the cell 10 is pressed by the ball 59, and the other surface of the lower end portion of the cell 10 is pressed against the vertical support surface Y. 10 is supported perpendicular to the optical axis. Further, when removing the lower end of the cell 10 from the lower recess 35c of the lower holder 35, the cell 10 may be pulled out upward.

Further, although the mounting bolt 50 is used as the holding means for the upper holder 43, it is not limited to this and any means can be used as long as it can hold the upper holder 43.

[0026]

As described above, in the flow cell holder of the particle size distribution measuring apparatus according to the first aspect, the flow cell holder is a light connecting the light source provided on one side of the cell and the detector provided on the other side. Since the support surface is formed so that the cell is perpendicular to the axis and one surface of the cell is pressed by the pressing means and the other surface of the cell is pressed against the support surface, the cell is simple and accurate. It can be installed in a precise position. Moreover, since the cell is not attached to the side holder as in the conventional case, a gap is not formed between the cell and the holder, and the cell does not rattle. Further, it is possible to prevent the cracking and distortion of the cell due to the mounting error of the cell and the holder and the processing error.

Further, in the flow cell holder of the particle size distribution measuring apparatus according to claim 2, the lower end portion of the flow cell is inserted into the lower recess of the lower holder, and the light source provided on one side of the cell on the bottom surface and side wall of the lower recess. And a detector provided on the other side of the cell, a support surface is formed to support the cell so that it is perpendicular to the optical axis, and the upper end of the flow cell is inserted into the upper recess of the upper holder. Pins protruding parallel to one end of the upper holder, supporting pieces of the supporting plate are mounted on both sides of the lower holder, and pressing bolts for pressing one surface of the cell to the supporting piece are screwed together, The other surface of the cell is pressed against the supporting surface, the pin is inserted into the elongated hole of the bent piece of the supporting plate, one end of the tension spring is locked to one end of the supporting piece of the supporting plate, and the other end is It is locked to the pin inserted in the hole and a compression spring is provided between the pin and the other end of the upper holder. Since the mounting bolts penetrate the other end of the upper holder and are screwed into the lower holder, when mounting the cell to the cell holder, insert both ends of the cell into the recesses of both holders and lower the mounting bolt. Since it is only necessary to screw it into the holder, the cell can be attached easily and accurately at an accurate position. Also, when the cell is attached to the cell holder, the compression spring of the attachment bolt is compressed, and at the same time, one end of the upper holder is pulled downward by the tension spring via the pin, and the lower recess is surrounded by the lower edge of the cell. The portions are pressed together, and the peripheral portions of the upper opening of the cell are pressed against the upper concave portion, so that the peripheral portions of the both openings can be reliably sealed. Moreover, it is not necessary to increase the dimensional accuracy of the upper holder and the lower holder, and liquid leakage from the both openings of the cell due to dimensional accuracy error and distortion and cracking of the cell due to pressure contact between the upper holder and the lower holder do not occur.

Further, when removing the cell from the cell holder, it suffices to remove the mounting bolt from the lower holder and loosen the pressing bolt, and the cell can be easily taken out from the lower recess of the lower holder, facilitating maintenance. it can.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

FIG. 2 is a cut front view of FIG.

FIG. 3 is a sectional plan view of FIG.

FIG. 4 is a cutaway plan view of a modification of the pressing means of FIG.

FIG. 5 is a schematic configuration diagram of a particle size distribution measuring device.

FIG. 6 is an exploded perspective view of a conventional flow cell holder.

[Explanation of symbols]

10 ... Flow cell, 34 ... Flow cell holder, 35 ... Lower holder, 35c ... Lower recess, 35e ... O ring, 36 ... Press bolt, 37 ... Introduction hole, 39 ... Introduction pipe, 41 ... Support plate, 41a ... Support piece, 41b ... bent piece, 41c ... long hole, 43 ... upper holder, 43a ... upper recess, 43c ... O-ring, 44 ... discharge hole, 46 ... discharge pipe, 47 ... pin, 4
8 ... tension spring, 50 ... mounting bolt, 52 ... compression spring, X
... horizontal support surface, Y ... vertical support surface.

Front page continued (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 15/02 G01B 11/08 G01N 15/14 G01N 21/01 G01N 21/05

Claims (2)

(57) [Claims] 1. A light source provided on one side of the cell and a detector provided on the other side of the cell, which is formed on a flow cell holder that supports a flow cell in which a sample solution in which a group of particles is dispersed in a dispersion medium flows. A supporting surface for supporting the cell so as to be perpendicular to the optical axis connecting the two, and pressing means for pressing one surface of the cell so that the other surface of the cell is in pressure contact with the supporting surface. Flow cell holder for particle size distribution measuring device. 2. A lower holder into which a lower end portion of a flow cell, through which a sample solution in which a group of particles is dispersed in a dispersion medium flows, is inserted into a lower recess, and a bottom surface and a side wall of the lower recess, the one side of the cell A supporting surface for supporting the cell so as to be perpendicular to an optical axis connecting a light source provided in the cell and a detector provided on the other side of the cell, and connecting the sample solution to the hole of the lower holder. A pipe for introducing or discharging, an upper holder for inserting the upper end of the cell into an upper recess and supporting the upper end, and a pipe for connecting to the hole of the upper holder for discharging or introducing the sample solution, O-rings that are respectively provided in both recesses and seal the peripheral portions of the upper surface opening and the lower surface opening of the cell; pins that project from both side surfaces of one end of the upper holder and that are parallel to the optical axis; The direction of the support piece is below Is mounted on both sides of the holder,
A tip of a vertically bent piece extending from one end of the support piece is screwed into the support plate located at one end of the upper holder, and the other surface of the cell is supported by the support plate. A pressing bolt that presses one surface of the cell so as to come into pressure contact with the surface, a long hole that is formed at the tip of the bent piece and through which the pin is inserted, and one end is locked to one end of the support piece. A tension spring, the other end of which is locked to the pin inserted into the elongated hole, a mounting bolt which penetrates the other end of the upper holder and is screwed into the lower holder, and the other end of the upper holder And a compression spring provided between the mounting bolt and the mounting bolt.