Pipe joint and particle size distribution measuring device

Abstract

This pipe joint is configured so that a first end surface and a second end surface are brought into contact as a result of an elastic member applying an axial-direction pressing force to an opposing surface in a state in which a connection mechanism connects a second tubular member and a cover body.

Description

Pipe fittings and particle size distribution measuring devices

[0001] The present invention relates to a pipe joint that constitutes a flow path through which a suspension in which particles are dispersed in a dispersion medium flows, and to a particle size distribution measuring device that uses the pipe joint.

[0002] As shown in Patent Document 1, for example, a conventional particle size distribution measuring device includes a flow cell through which a suspension in which particles to be measured are dispersed in a dispersion medium is stored, the flow cell is connected to the suspension via a circulation flow path, and the suspension flowing through the flow cell is irradiated with an inspection light, and the particle size distribution of the particles is measured based on the diffracted and / or scattered light.

[0003] Japanese Patent Application Laid-Open No. 2008-249724

[0004] In the particle size distribution measuring device described above, the circulation flow path may be configured to be separable using, for example, a pipe fitting as shown in Fig. 7. This type of pipe fitting may include a cylindrical female part (hereinafter also referred to as a first tubular member) whose internal space constitutes part of the flow path, a cylindrical male part (hereinafter also referred to as a second tubular member) that is inserted into the female part and whose internal space constitutes part of the flow path, a groove formed on the outer circumferential surface of the female part, and a claw portion provided on the outer circumferential surface of the male part that fits into the groove. When the male part is inserted into the female part, the claw portion fits into the groove, thereby connecting the male part and the female part.

[0005] However, in the above-mentioned pipe fitting, even when the tabs are fitted into the grooves, there is still play between the male and female parts, which can cause particles to become caught between the male and female parts. As a result, the connection between the male and female parts becomes stiff, making it difficult for the user to remove the male and female parts.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its main objective is to prevent particles from becoming caught between a first tubular member and a second tubular member in a pipe fitting that forms a flow path through which a suspension in which particles are dispersed in a dispersion medium flows.

[0007] that is, the pipe fitting of the present invention is a pipe fitting that forms a flow path through which a suspension having particles dispersed in a dispersion medium flows, and is equipped with a first tubular member having a first end face at which a first flow path that is a part of the flow path opens, a second tubular member having a second end face at which a second flow path that is a part of the flow path opens, a bottomed, cylindrical cover body into whose bottom the first tubular member is slidably inserted, a connection mechanism that connects the second tubular member and the cover body, and a pressing mechanism that brings the first end face and the second end face into contact, wherein the pressing mechanism has an inward surface that is provided at the bottom of the cover body and faces the first end face, an opposing surface that is provided on the first tubular member and faces the inward surface in the axial direction of the first tubular member, and an elastic member that is provided between the inward surface and the opposing surface, and wherein, with the connection mechanism causing the first end face and the second end face to face each other, the elastic member applies a pressing force in the axial direction to the opposing surface, thereby bringing the first end face and the second end face into contact.

[0008] With this configuration, when the second tubular member and the cover body are connected by the connection mechanism, the elastic member applies an axial force to the opposing surfaces to bring the first end face and the second end face into contact, thereby fixing the first tubular member and the second tubular member in a state where the first end face and the second end face are in contact, making it difficult for particles to become caught between the first end face and the second end face.

[0009] The connection mechanism has a protrusion portion provided on one of the outer peripheral surface of the second tubular member or the inner peripheral surface of the cover body, and a guide portion provided on the other of the outer peripheral surface of the second tubular member or the inner peripheral surface of the cover body, which guides the protrusion portion from an insertion position where the second tubular member is inserted into the cover body to a connection position where the second tubular member and the cover body are connected, and the elastic member is configured to bring the first end face and the second end face into contact by applying a pressing force in the axial direction against the opposing surface when the protrusion portion is positioned at the connection position.

[0010] With this configuration, the guide portion guides the protrusion portion from the insertion position to the connection position, and when the protrusion portion is positioned at the connection position, the elastic member applies axial pressure against the opposing surface, bringing the first end face and the second end face into contact, so that the second tubular member and the cover body can be easily connected by the guide portion.

[0011] It is preferable that the cover body is rotated in the axial direction from the insertion position, causing the inward surface and the opposing surface to come into contact via the elastic member, and moving the cover body and the first tubular member toward the second tubular member, so that the guide portion guides the protrusion portion to the connection position.

[0012] With this configuration, by rotating the cover body from the insertion position, the cover body and the first tubular member are moved toward the second tubular member, and the guide portion guides the protrusion portion to the connection position, so that the first end face and the second end face can be easily brought close together simply by the guide portion guiding the protrusion portion to the connection position.

[0013] It is preferable that the guide portion is formed with a protrusion fixing portion that fixes the protrusion portion at the connection position by receiving the pressing force of the elastic member when the first end face and the second end face are in contact with each other through the elastic member.

[0014] With this configuration, the protrusion is fixed at the connection position by the protrusion fixing portion, so that the first end surface and the second end surface can be maintained in contact with each other.

[0015] It is preferable that the inner diameter of the opening of the first flow path formed on the first end face and the inner diameter of the opening of the second flow path formed on the second end face are the same, and that when the first end face and the second end face are in contact with each other by the elastic member, the opening of the first flow path formed on the first end face and the opening of the first flow path formed on the second end face coincide with each other.

[0016] With this configuration, the inner diameter of the opening of the first flow path formed in the first end face is the same as the inner diameter of the opening of the second flow path formed in the second end face, and when the first end face and the second end face are in contact, the opening of the first flow path formed in the first end face and the opening of the second flow path formed in the second end face coincide with each other, so that the contact points of the first end face and the second end face can be made flush, which further prevents particles from getting caught between the first end face and the second end face and prevents distortion of the flow path.

[0017] A specific aspect of the opposing surface is one in which the first tubular member further includes a flange portion formed closer to the first end face than the inward surface, and the opposing surface is a surface of the flange portion that faces the inward surface.

[0018] With this configuration, the elastic member can bring the first end surface and the second end surface into contact with each other by applying a pressing force to the opposing surface of the flange portion that faces the inward surface of the cover body.

[0019] The second tubular member is formed to surround the second end face and has a surrounding portion into which the first tubular member is inserted, and when the first tubular member is inserted into the surrounding portion, the inner peripheral surface of the surrounding portion contacts the outer peripheral surface of the first tubular member.

[0020] With this configuration, when the first tubular member is inserted into the surrounding portion, the inner peripheral surface of the surrounding portion contacts the outer peripheral surface of the first tubular member, making it easy to position the first tubular member relative to the second tubular member.

[0021] It is desirable that the device further include a seal member interposed between the inner peripheral surface of the surrounding portion and the outer peripheral surface of the first tubular member when the first tubular member is inserted into the surrounding portion.

[0022] With this configuration, the seal member is interposed between the inner circumferential surface of the enclosing portion and the outer circumferential surface of the first tubular member when the first tubular member is inserted into the enclosing portion, thereby maintaining an airtight seal between the inner circumferential surface of the enclosing portion and the outer circumferential surface of the first tubular member. Furthermore, by interposing the seal member between the inner circumferential surface of the enclosing portion and the outer circumferential surface of the first tubular member, the axial centers of the first tubular member and the second tubular member can be aligned.

[0023] In particle size distribution measuring devices, the circulation flow path may be separated using a pipe joint in order to clean the circulation flow path. With conventional pipe joints, repeated use of the pipe joint causes a gap to form between the first tubular member and the second tubular member, making it difficult to use the pipe joint repeatedly. Therefore, the particle size distribution measuring device of the present invention includes a cell for measuring particle size distribution and a circulation flow path for circulating the suspension through the cell, and the circulation flow path is configured to be separable using the pipe joint.

[0024] With this configuration, an elastic member is used to fix the first tubular member and the second tubular member, so the circulation flow path can be separated multiple times using the pipe fitting compared to conventional pipe fittings.

[0025] Specifically, the device comprises a circulation bus unit having a circulation bus in which the suspension is stored, and an apparatus main unit having the cell, the circulation bus and the cell being connected via the circulation flow path, and the circulation flow path between the apparatus main unit and the circulation bus unit being configured to be separable using the pipe fitting.

[0026] According to the present invention, in a pipe fitting that forms a flow path through which a suspension in which particles are dispersed in a dispersion medium flows, it is possible to prevent particles from becoming caught between a first tubular member and a second tubular member.

[0027] Fig. 1 is a schematic diagram of a particle size distribution measuring device according to one embodiment of the present invention; Fig. 2 is a perspective view showing a pipe fitting according to the same embodiment; Fig. 3 is a cross-sectional view of the pipe fitting according to the same embodiment taken along line A-A; Fig. 4 is a top view of the pipe fitting according to the same embodiment; (a) a cross-sectional view of line A-A and (b) a top view of the pipe fitting at the inserted position according to the same embodiment; (a) a cross-sectional view of line A-A and (b) a top view of the pipe fitting at a position between the inserted position and the connected position according to the same embodiment; Fig. 2 is a schematic diagram showing a conventional pipe fitting;

[0028] A particle size distribution measuring device according to one embodiment of the present invention will be described below with reference to the drawings. Note that in all of the drawings shown below, some parts may be omitted or exaggerated in schematic form for ease of understanding. Identical components will be assigned the same reference numerals, and their description will be omitted where appropriate.

[0029] <Device Configuration> The particle size distribution measuring device 100 of this embodiment is a laser diffraction / scattering type that measures the particle size distribution of particles contained in a sample based on diffracted light and / or scattered light generated by irradiating the sample with light. In this embodiment, the sample is, for example, a pharmaceutical product, food product, and / or a chemical industrial product. In this case, the sample is composed of a liquid dispersion medium and particles, and the particles dispersed in the liquid are the measurement target.

[0030] 1, the particle size distribution measuring device 100 includes an apparatus main body unit 2 provided with a cell 21 for measuring particle size distribution, a circulation bus unit 3 provided with a circulation bus 31 in which a suspension in which particles are dispersed in a dispersion medium is stored, a circulation flow path 4 for circulating the suspension through the cell 21, and a pipe joint 5 configured to allow the circulation flow path 4 to be separated. The configuration of each part will be described below.

[0031] First, the apparatus main body unit 2 will be described.

[0032] The main unit 2 of the device comprises a cell 21, a light irradiation section 22 that irradiates light onto the sample in the cell 21, a detector 23 that detects diffracted light and / or scattered light generated from the sample, and a control device 24 that performs various arithmetic processing based on the light intensity signal output by the detector 23.

[0033] The cell 21 is a circulation type flow cell. Specifically, the cell 21 includes an inlet port (not shown) through which a sample is supplied, an outlet port (not shown) through which the sample is discharged, and an internal flow path connected to the inlet port and the outlet port and through which the sample flows.

[0034] The light irradiating unit 22 irradiates light onto the sample flowing through the internal flow path of the cell 21. Examples of the light irradiating unit 22 include a semiconductor laser and an LED. The light irradiating unit 22 may irradiate light onto the sample via an optical member such as a lens.

[0035] The detector 23 detects the light intensity of the diffracted light and / or scattered light generated by the irradiation of light according to the divergence angle, and here, multiple detectors are provided to detect the light intensity of the diffracted light and / or scattered light according to the divergence angle.

[0036] The control device 24 is a general-purpose or dedicated computer equipped with a CPU, a memory, an input / output interface, etc., and performs at least the function of a particle size distribution calculation unit by causing the CPU and peripheral devices to cooperate in accordance with a predetermined program stored in a predetermined area of ​​the memory.

[0037] The particle size distribution calculation unit calculates the particle size distribution of particles contained in the sample based on the light intensity signals output from the detectors 23. Specifically, the particle size distribution corresponding to the scattering pattern is calculated based on a scattering pattern indicated by the light intensity signals output from each detector 23, the scattering pattern being composed of the scattering angle and the intensity of the scattered light at that scattering angle, and a theoretical calculation formula such as the Mie scattering theory. Particle size distribution data indicating the particle size distribution calculated by the particle size distribution calculation unit is stored in a predetermined memory and is also displayed on a display unit D, such as a display.

[0038] Next, the circulation bus unit 3 will be described.

[0039] The circulation bath unit 3 includes the above-mentioned circulation bath 31 and a circulation pump 32 that supplies the suspension stored in the circulation bath 31 to the measurement cell.

[0040] The circulation bus 31 is used to mix particles with a dispersion medium to disperse the particles, thereby forming a suspension. The circulation bus 31 may be provided with a stirring device (not shown) or the like to stir the particles in the dispersion medium.

[0041] Next, the circulation flow path 4 will be described.

[0042] The circulation flow path 4 connects the cell 21 and the circulation bus 31, and circulates the suspension between the circulation bus 31 and the cell 21. Specifically, the circulation flow path 4 includes an outgoing path section 41 that connects the outlet of the circulation bus 31 to the inlet port of the cell 21, and a returning path section 42 that connects the outlet port of the cell 21 to the circulation bus 31.

[0043] In this embodiment, the circulation flow path 4 is provided with the cell 21, the circulation bus 31, and the circulation pump 32. In this embodiment, the circulation pump 32 is provided in the outgoing path section 41, specifically, in the outgoing path section 41 between the outlet of the circulation bus 31 and the inlet port of the cell 21. The circulation flow path 4 may be provided with, for example, a particle agitator or the like for dispersing the particles in the liquid. The circulation pump 32 may also be provided in the return path section 42.

[0044] <Configuration of Pipe Joint> Next, the pipe joint 5 will be described.

[0045] The pipe fitting 5 allows the circulation flow path 4 to be separated, and constitutes a part of the circulation flow path 4. In this embodiment, the pipe fitting 5 allows the circulation flow path 4 between the apparatus main body unit 2 and the circulation bus unit 3 to be separated. Note that the pipe fitting 5 is not limited to a fitting that allows the circulation flow path 4 between the apparatus main body unit 2 and the circulation bus unit 3 to be separated, but may also be a fitting that allows the circulation flow path 4 within the apparatus main body unit 2 and / or the circulation flow path 4 within the circulation bus unit 3 to be separated. Also, in FIG. 1 , the pipe fitting 5 allows the outgoing path portion 41 to be separated, but the return path portion 42 may also be separated.

[0046] 2 and 3, the pipe joint 5 comprises a first tubular member 51 and a second tubular member 52 that are configured to be separable from each other, a cover body 53 into which the first tubular member 51 is slidably inserted, a connection mechanism 54 that connects the second tubular member 52 and the cover body 53, and a pressing mechanism 55 that applies a pressing force, and the first tubular member 51 and the second tubular member 52 are fixed together by the connection mechanism 54 and the pressing mechanism 55. Each part that makes up the pipe joint 5 will be described below.

[0047] The first tubular member 51 has a first end surface S1 at which a first flow path L1, which is a part of the circulation flow path 4, opens. Specifically, the first tubular member 51 has a circular tubular shape with both ends open, and one end surface in the axial direction of the first tubular member 51 (hereinafter simply referred to as the axial direction) constitutes the first end surface S1. Furthermore, the first flow path L1 is formed along the axial direction in the internal space of the first tubular member 51. The end surface opposite the first end surface S1 in the axial direction is connected to the outgoing path section 41. Note that, although the first tubular member 51 has a straight pipe shape in this embodiment, it is not limited to a straight pipe shape as long as it has a tubular shape. Furthermore, the first flow path L1 constitutes a part of the outgoing path section 41, but may also constitute a part of the returning path section 42.

[0048] The second tubular member 52 has a second end surface S2 at which the second flow path L2, which is part of the circulation flow path 4, opens. The second tubular member 52 has a generally circular tubular shape with both ends open. Specifically, the second tubular member 52 has a second tubular member main body 521 provided with the second end surface S2, and an enclosing portion 522 formed to surround the second end surface S2.

[0049] The second tubular member main body 521 has a generally straight pipe shape, and one axial end face of the second tubular member main body 521 constitutes a second end face S2. A second flow path L2 is formed in the internal space of the second tubular member main body 521 along the axial direction of the second tubular member 52. The axial end face of the second tubular member 52 opposite the second end face S2 is connected to the circulation flow path 4, which is connected to the outlet of the circulation bus 31. In this embodiment, the second tubular member main body 521 is fixed to the side wall of the housing 33 that houses the circulation bus 31. Note that, although the second tubular member main body 521 has a straight pipe shape in this embodiment, it is not limited to a straight pipe shape as long as it is tubular. The second flow path L2 constitutes a part of the outward path section 41, but may also constitute a part of the return path section 42.

[0050] The inner diameter of the opening of the second flow passage L2 formed in the second end face S2 is the same as the inner diameter of the opening of the first flow passage L1 formed in the first end face S1. When the first end face S1 and the second end face S2 are in contact with each other, the opening of the first flow passage L1 formed in the first end face S1 and the opening of the second flow passage L2 formed in the second end face S2 coincide with each other.

[0051] The surrounding portion 522 is provided on the outer peripheral surface of the second tubular member main body 521 so as to surround the second end face S2, and the first tubular member 51 is inserted into the surrounding portion 522. Specifically, the surrounding portion 522 is generally cylindrical, and opens from one end of the second tubular member main body 521 where the second end face S2 is provided toward the outside of the second end face S2.

[0052] When the first tubular member 51 is inserted into the surrounding portion 522, the inner circumferential surface of the surrounding portion 522 contacts the outer circumferential surface of the first tubular member 51. Specifically, the end of the first tubular member 51 in the axial direction, where the first end surface S1 is provided, is inserted from the opening of the surrounding portion 522 toward the second end surface S2, and in this state, the inner circumferential surface of the surrounding portion 522 contacts the outer circumferential surface of the first tubular member 51 via the seal member 56.

[0053] The seal member 56 keeps the inner circumferential surface of the surrounding portion 522 and the outer circumferential surface of the first tubular member 51 airtight, and aligns the axial center of the first tubular member 51 with the axial center of the second tubular member 52. Specifically, the seal member 56 is an annular member, such as an O-ring, and is housed in a groove G formed in the outer circumferential surface of the first tubular member 51 over the entire circumferential direction of the first tubular member 51. Note that the groove G that houses the seal member 56 may also be formed on the inner circumferential surface of the surrounding portion 522. Furthermore, although the seal member 56 is provided over the entire circumferential direction of the first tubular member 51, it may also be provided in a part of the first tubular member 51 or a part of the surrounding portion 522.

[0054] The cover body 53 has a cylindrical shape with a bottom, and the first tubular member 51 is slidably inserted into the bottom portion 531. Specifically, the cover body 53 has the bottom portion 531 and a cylindrical portion 532 that opens from the bottom portion 531 toward the first end surface S1 in the axial direction.

[0055] The bottom 531 has a flat plate-like shape. An opening is formed in the bottom 531, penetrating from one surface to the other, and into which the first tubular member 51 is slidably inserted. The inner diameter of the opening is approximately the same as or slightly larger than the outer diameter of the first tubular member 51.

[0056] The tubular portion 532 has a cylindrical shape and covers the outer peripheral surface of the first tubular member 51. In the present embodiment, when the first tubular member 51 is inserted into the surrounding portion 522, the tubular portion 532 covers the outer peripheral surface of the first tubular member 51 and the outer peripheral surface of the surrounding portion 522. The inner diameter of the tubular portion 532 is approximately the same as or slightly larger than the outer diameter of the surrounding portion 522.

[0057] The connection mechanism 54 connects the second tubular member 52 and the cover body 53 with the first end face S1 and the second end face S2 facing each other. Specifically, the connection mechanism 54 has a protrusion 541 provided on the outer circumferential surface of the second tubular member 52 and a guide portion 542 provided on the inner circumferential surface of the cover body 53 to guide the protrusion 541.

[0058] The protrusion 541 is provided on the outer circumferential surface of the surrounding portion 522 of the second tubular member 52. The protrusion 541 has a cylindrical shape extending from the outer circumferential surface of the surrounding portion 522 toward the radially outer side of the surrounding portion 522. Note that the protrusion 541 is not limited to being cylindrical, and may have other shapes, such as a convex shape, extending from the outer circumferential surface of the surrounding portion 522.

[0059] The guide portion 542 guides the protrusion 541 from an insertion position P1, where the second tubular member 52 is inserted into the cover body 53, to a connection position P2, where the second tubular member 52 and the cover body 53 are connected. Specifically, the guide portion 542 is a gap that penetrates from the inner peripheral surface to the outer peripheral surface of the cover body 53. Note that the guide portion 542 does not have to penetrate from the inner peripheral surface to the outer peripheral surface of the cover body 53, and may be a recess or groove that is recessed radially outward from the inner peripheral surface of the cover body 53.

[0060] 4 , the guide portion 542 extends from the open end of the cylindrical portion 532 of the cover body 53 to the bottom portion 531 of the cover body 53. Specifically, the guide portion 542 extends from an insertion position P1 provided on the open end side of the cylindrical portion 532, along the circumferential direction of the cylindrical portion 532, to the bottom portion 531 of the cover body 53, and to a connection position P2 provided on the bottom portion 531 side of the cylindrical portion 532. In order for the guide portion 542 to guide the protrusion 541, the width of the gap from the insertion position P1 to the connection position P2 is configured to be slightly larger than the inner diameter of the protrusion 541.

[0061] As shown in FIG. 4 , the guide portion 542 is formed with a protrusion fixing portion 543 that fixes the protrusion 541 at the connection position P2 by receiving a pressing force from an elastic member 553 (described later) when the first end surface S1 and the second end surface S2 are in contact with each other. The protrusion fixing portion 543 prevents the protrusion 541 from moving from the connection position P2 when the protrusion 541 is located at the connection position P2. Specifically, the protrusion fixing portion 543 has a shape that surrounds the outer circumferential surface of the protrusion 541. In this embodiment, the protrusion fixing portion 543 is a wall surface of a circular opening in a top view, as shown in FIG. 4 . Note that the shape of the protrusion fixing portion 543 is not limited to the wall surface of a circular opening in a top view, as long as it can fix the protrusion 541 at the connection position P2. The inner diameter of the protrusion fixing portion 543 is slightly larger than the inner diameter of the protrusion 541.

[0062] The pressing mechanism 55 applies a pressing force to bring the first end surface S1 and the second end surface S2 into contact with each other. Specifically, the pressing mechanism 55 has an inward surface 551 provided on the bottom 531 of the cover body 53 and facing the first end surface S1, an opposing surface 552 provided on the first tubular member 51 and opposing the inward surface 551 in the axial direction, and an elastic member 553 provided between the inward surface 551 and the opposing surface 552.

[0063] The inward surface 551 is a surface that faces the first end surface S1 among the surfaces that constitute the bottom portion 531 of the cover body 53. In this embodiment, the inward surface 551 is a flat surface.

[0064] The opposing surface 552 is a surface that is provided axially closer to the first end face S1 than the inward surface 551. Specifically, the flange portion 57 is formed in the first tubular member 51 closer to the first end face S1 than the inward surface 551, and the surface of the flange portion 57 that faces the inward surface 551 is the opposing surface 552.

[0065] The outer diameter of the flange portion 57 is configured to be approximately the same as or slightly smaller than the inner diameter of the cylindrical portion 532 of the cover body 53, so that the outer circumferential surface of the flange portion 57 contacts the inner circumferential surface of the cylindrical portion 532. In this embodiment, as shown in Fig. 3, a rotation prevention portion 58 such as an O-ring that prevents the first tubular member 51 from rotating relative to the cylindrical portion 532 in the circumferential direction is interposed between the outer circumferential surface of the flange portion 57 and the inner circumferential surface of the cylindrical portion 532.

[0066] The elastic member 553 is provided between the inward surface 551 and the opposing surface 552, and applies a pressing force in the axial direction to the opposing surface 552 while the second tubular member 52 and the cover body 53 are connected by the connection mechanism 54, thereby bringing the first end surface S1 and the second end surface S2 into contact. In this embodiment, the elastic member 553 is an annular member into which the first tubular member 51 is slidably inserted, such as a wave washer.

[0067] The pressing force of the elastic member 553 is an elastic restoring force generated by being sandwiched between the inward surface 551 and the opposing surface 552. Specifically, when the cover body 53 is rotated from the insertion position P1 with the protrusion 541 positioned at the insertion position P1 to guide the protrusion 541 of the connection mechanism 54 to the connection position P2, the elastic member 553 is sandwiched between the inward surface 551 and the opposing surface 552, thereby storing energy in the elastic member 553. Then, when the protrusion 541 is positioned at the connection position P2, the elastic restoring force of the elastic member 553 is applied to the opposing surface 552 along the axial direction. As a result, the first end surface S1 of the first tubular member 51 is further pressed against the second end surface S2 of the second tubular member 52, and the first end surface S1 and the second end surface S2 come into contact with each other.

[0068] Furthermore, the protrusion 541 is fixed at the connection position P2 by the protrusion fixing portion 543 due to the pressing force of the elastic member 553. Specifically, the first end surface S1 is further pressed against the second end surface S2 by the pressing force of the elastic member 553, and the protrusion 541 is pressed against the wall surface of the protrusion fixing portion 543.

[0069] <Method of Mounting and Removing Pipe Joint> Next, a method of mounting and removing the pipe joint 5 of this embodiment will be described.

[0070] First, the method of attaching the pipe joint 5 will be described with reference to FIGS.

[0071] An elastic member 553 is provided on the inward surface 551 of the cover body 53, and the first tubular member 51 is slidably inserted into the cover body 53. In this state, the elastic member 553 is provided between the inward surface 551 of the cover body 53 and the opposing surface 552 of the flange portion 57.

[0072] Then, with the first end surface S1 of the first tubular member 51 and the second end surface S2 of the second tubular member 52 facing each other, the first tubular member 51, the cover body 53, and the elastic member 553 are moved toward the second tubular member 52 to position the protrusion 541 at the insertion position P1, as shown in Figures 5(a) and 5(b). Note that, although Figure 5(a) shows the first end surface S1 and the second end surface S2 in contact with each other at the insertion position P1, the first end surface S1 and the second end surface S2 do not necessarily have to be in contact with each other at the insertion position P1.

[0073] Next, by rotating the cover body 53 from the insertion position P1, the inward surface 551 and the opposing surface 552 come into contact with each other via the elastic member 553, as shown in Fig. 6(a), and the cover body 53 and the first tubular member 51 are moved toward the second tubular member 52. As a result, the protrusion 541 is guided along the guide portion 542 toward the connection position P2, as shown in Fig. 6(b).

[0074] Furthermore, as the protrusion 541 is guided along the guide portion 542 toward the connection position P2, the first end surface S1 of the first tubular member 51 and the second end surface S2 of the second tubular member 52 press against each other, thereby reducing the distance between the inward surface 551 and the opposing surface 552. As a result, the inward surface 551 and the opposing surface 552 sandwich the elastic member 553, causing the elastic member 553 to be energized. In FIG. 6( a ), when the elastic member 553 is energized, the open end of the surrounding portion 522 is spaced from the flange portion 57. Therefore, compared to when the open end of the surrounding portion 522 presses against the flange portion 57, the pressing force of the elastic member 553 is concentrated on the first end surface S1 and the second end surface S2. Note that the open end of the surrounding portion 522 may also press against the flange portion 57.

[0075] 3 and 4 , when the protrusion 541 is located at the connection position P2, the first end face S1 is pressed against the second end face S2 by the pressing force of the elastic member 553 applied in the axial direction to the opposing surface 552. As a result, the first end face S1 and the second end face S2 come into contact with each other with no gap between them. In this state, the opening of the first flow path L1 formed in the first end face S1 and the opening of the second flow path L2 formed in the second end face S2 are aligned.

[0076] Then, the pressing force of the elastic member 553 presses the protrusion 541 against the wall surface of the protrusion fixing portion 543, and the protrusion 541 is fixed at the connection position P2, thereby maintaining the first end surface S1 and the second end surface S2 in contact with each other.

[0077] Next, a method for removing the pipe joint 5 will be described.

[0078] With the protrusion 541 positioned at the connection position P2, the cover body 53 is rotated from the connection position P2 in the direction opposite to the attachment method to release the protrusion 541 from the protrusion fixing portion 543. When the protrusion 541 is released from the protrusion fixing portion 543, the elastic restoring force of the elastic member 553 makes it easy for the first end surface S1 of the first tubular member 51 and the second end surface S2 of the second tubular member 52 to separate. Then, the protrusion 541 is guided along the guide portion 542 toward the insertion position P1.

[0079] When the protrusion 541 is positioned at the insertion position P1, the cover body 53 and the first tubular member 51 are separated from the second tubular member 52. As a result, the first tubular member 51 and the second tubular member 52 are separated.

[0080] Effect of the Present Embodiment According to the particle size distribution measuring device 100 of the present embodiment, with the second tubular member 52 and the cover body 53 connected by the connection mechanism 54, the elastic member 553 applies a force in the axial direction to the opposing surface 552 to bring the first end surface S1 and the second end surface S2 into contact with each other, thereby fixing the first tubular member 51 and the second tubular member 52 with the first end surface S1 and the second end surface S2 in contact with each other. As a result, particles are less likely to become caught between the first end surface S1 and the second end surface S2, making it easier for the user to remove the first tubular member 51 and the second tubular member 52. Furthermore, the first tubular member 51 and the second tubular member 52 can be attached and detached by rotating the cover body 53 and guiding the protrusion 541 along the guide portion 542, thereby eliminating the need for tools to attach and detach the first tubular member 51 and the second tubular member 52. Furthermore, since the guide portion 542 extends circumferentially around the tubular portion 532 toward the bottom 531 of the cover body 53, the number of rotations required to rotate the second tubular member 52 circumferentially can be reduced compared to a configuration in which the connection mechanism 54 screws together the first tubular member 51 and the second tubular member 52.

[0081] Other Embodiments The present invention is not limited to the above-described embodiments.

[0082] In the above embodiment, the elastic member 553 is, for example, a wave washer or the like that has an annular shape and into which the first tubular member 51 is slidably inserted, but is not limited to this. For example, the elastic member 553 may be, for example, a coil spring or the like that is interposed between the inward surface 551 and the opposing surface 552.

[0083] In the above embodiment, the particle size distribution measuring device 100 measures particle size distribution using a light intensity signal obtained from diffracted light and / or scattered light, but is not limited to this. For example, the particle size distribution measuring device 100 may measure particle size distribution using other analytical methods such as dynamic scattering, centrifugal sedimentation, and particle analysis.

[0084] In the above embodiment, the first flow path L1 and the second flow path L2 constitute a part of the outward path section 41 and / or a part of the return path section 42, but this is not limiting. For example, the first flow path L1 and / or the second flow path L2 may be connected to the outward path section 41, or the first flow path L1 and / or the second flow path L2 may be connected to the return path section 42.

[0085] In the above embodiment, the cylindrical portion 532 opens from the bottom 531 in the axial direction toward the first end face S1, but it may also open from the bottom 531 in the axial direction toward the opposite side of the first end face S1.

[0086] In the above embodiment, the protrusion 541 is provided on the second tubular member 52 and the guide portion 542 is provided on the cover body 53, but the protrusion 541 may be provided on the cover body 53 and the guide portion 542 may be provided on the second tubular member 52. Furthermore, the configuration of the connection mechanism 54 that connects the second tubular member 52 and the cover body 53 is not limited to the protrusion 541 and the guide portion 542. For example, the connection mechanism 54 may be a joining member, such as an adhesive or tape, that joins the second tubular member 52 and the cover body 53 together, or may be, for example, a fastener that fastens the cover body 53 in a state in which the second tubular member 52 is inserted into the cover body 53.

[0087] In the above embodiment, the pipe joint 5 includes the sealing member 56 and the anti-rotation portion 58 , but the pipe joint 5 does not necessarily need to include the sealing member 56 and the anti-rotation portion 58 .

[0088] In the above embodiment, the pipe joint 5 constitutes the circulation flow path 4 of the particle size distribution measuring device 100, but is not limited to this. The pipe joint 5 may also constitute a flow path through which a suspension flows that is used in a device other than the particle size distribution measuring device 100. Furthermore, the pipe joint 5 may be used in a flow path through which the suspension flows in a predetermined direction to the cell 21, in addition to the circulation flow path 4 through which the suspension circulates between the cell 21 and the circulation bus 31.

[0089] In addition, the present invention can be modified in various ways without departing from the spirit of the invention.

[0090] According to the present invention, in a pipe fitting that forms a flow path through which a suspension in which particles are dispersed in a dispersion medium flows, it is possible to prevent particles from becoming caught between a first tubular member and a second tubular member.

[0091] DESCRIPTION OF SYMBOLS 100 Particle size distribution measuring device 2 Device main unit 21 Cell 3 Circulation bus unit 31 Circulation bus 4 Circulation flow path 5 Pipe joint 51 First tubular member 52 Second tubular member 522 Surrounding portion 53 Cover body 54 Connection mechanism 541 Projection portion 542 Guide portion 543 Projection fixing portion 55 Pressing mechanism 551 Inward surface 552 Opposing surface 553 Elastic member 56 Sealing member 57 Flange portion S1 First end face S2 Second end face L1 First flow path L2 Second flow path P1 Insertion position P2 Connection position

Claims

1. A pipe fitting forming a flow path through which a suspension in which particles are dispersed in a dispersion medium flows, comprising: a first tubular member having a first end face at which a first flow path that is a part of the flow path opens; a second tubular member having a second end face at which a second flow path that is a part of the flow path opens; a bottomed, cylindrical cover body into whose bottom the first tubular member is slidably inserted; a connection mechanism connecting the second tubular member and the cover body; and a pressing mechanism bringing the first end face and the second end face into contact, wherein the pressing mechanism has: an inward surface provided at the bottom of the cover body and facing the first end face; an opposing surface provided on the first tubular member that faces the inward surface in the axial direction of the first tubular member; and an elastic member provided between the inward surface and the opposing surface, a connecting mechanism that causes the first end surface and the second end surface to face each other, and the elastic member that applies a pressing force in the axial direction to the facing surface, thereby bringing the first end surface and the second end surface into contact.

2. A pipe fitting as described in claim 1, wherein the connection mechanism has a protrusion provided on one of the outer peripheral surface of the second tubular member or the inner peripheral surface of the cover body, and a guide portion provided on the other of the outer peripheral surface of the second tubular member or the inner peripheral surface of the cover body, for guiding the protrusion from an insertion position where the second tubular member is inserted into the cover body to a connection position where the second tubular member and the cover body are connected, and the elastic member applies a pressing force in the axial direction against the opposing surface with the protrusion located at the connection position, thereby bringing the first end face and the second end face into contact.

3. A pipe fitting as described in claim 2, wherein the cover body is rotated from the insertion position, thereby bringing the inward surface and the opposing surface into contact via the elastic member, and moving the cover body and the first tubular member toward the second tubular member, thereby causing the guide portion to guide the protrusion portion to the connection position.

4. A pipe fitting as described in claim 2 or 3, wherein the guide portion is formed with a protrusion fixing portion that fixes the protrusion portion at the connection position by receiving the pressing force of the elastic member when the first end face and the second end face are in contact with each other by the elastic member.

5. A pipe fitting as claimed in any one of claims 1 to 4, wherein the inner diameter of the opening of the first flow path formed in the first end face is the same as the inner diameter of the opening of the second flow path formed in the second end face, and the opening of the first flow path formed in the first end face and the opening of the first flow path formed in the second end face coincide with each other when the first end face and the second end face are in contact with each other by the elastic member.

6. A pipe fitting as claimed in any one of claims 1 to 5, further comprising a flange portion formed on said first tubular member closer to said first end face than said inward-facing surface, and said opposing surface being a surface of said flange portion that faces said inward-facing surface.

7. A pipe fitting as claimed in any one of claims 1 to 6, wherein the second tubular member is formed to surround the second end face and has a surrounding portion into which the first tubular member is inserted, and when the first tubular member is inserted into the surrounding portion, the inner circumferential surface of the surrounding portion contacts the outer circumferential surface of the first tubular member.

8. A pipe fitting as described in claim 7, further comprising a sealing member interposed between the inner peripheral surface of the surrounding portion and the outer peripheral surface of the first tubular member when the first tubular member is inserted into the surrounding portion.

9. A particle size distribution measuring device comprising: a cell for measuring particle size distribution; and a circulation flow path for circulating the suspension through the cell, wherein the circulation flow path is configured to be separable using a pipe fitting according to any one of claims 1 to 8.

10. A particle size distribution measuring device as described in claim 9, comprising: a circulation bus unit provided with a circulation bus in which the suspension is stored; and an apparatus main unit provided with the cell, wherein the circulation bus and the cell are connected via the circulation flow path, and wherein the circulation flow path between the apparatus main unit and the circulation bus unit is configured to be separable using a pipe fitting as described in any one of claims 1 to 7.

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