Piping connection mechanism

Abstract

To enable easy removal / insertion of a first pipe in a mechanism in which one end of the first pipe is inserted into an end of a second pipe to be connected thereto.SOLUTION: A pipe connection mechanism includes: a first connection member 140 including a first cylinder part 142 into which a first pipe 131 is inserted, and a first facing surface 148 arranged orthogonal to an axis of the first cylinder part; and a second connection member 150 including a second cylinder part 152 into which one end of a second pipe 124 having an inner diameter larger than an outer diameter of the first pipe is inserted, and a second facing surface 157 arranged orthogonal to an axis of the second cylinder part. The first facing surface and the second facing surface face each other in a state where the one end of the first pipe is inserted into the one end of the second pipe. The pipe connection mechanism includes: a first seal member 161 for sealing a space between an outer peripheral surface of the first pipe and an inner peripheral surface of the first cylinder part; a second seal member 162 for sealing a space between an outer peripheral surface of the second pipe and an inner peripheral surface of the second cylinder part; and a third seal member 163 sandwiched between the first facing surface and the second facing surface.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pipe connection mechanism for inserting one end of a pipe into the end of another pipe to connect them in a liquid-tight or air-tight manner. [Background technology]

[0002] One method of mass spectrometry is MS / MS analysis, which involves dissociating ions with a specific mass-to-charge ratio (strictly speaking, m / z) and then performing mass analysis of the resulting product ions. There are various configurations of mass spectrometers for performing MS / MS analysis, but the most widely used is the tandem quadrupole (also called triple quadrupole) mass spectrometer, which has a relatively simple structure and is inexpensive.

[0003] For example, a tandem quadrupole mass spectrometer described in Patent Document 1 includes a front-stage quadrupole mass filter, a collision cell (collision chamber), a rear-stage quadrupole mass filter, an ion detector, a vacuum chamber housing these components, and a radical supply unit disposed outside the vacuum chamber. The front-stage quadrupole mass filter selectively passes only ions having a predetermined m / z value among various ions derived from the target compound, and the ions that pass through the front-stage quadrupole mass filter are introduced into the collision cell as precursor ions. The precursor ions introduced into the collision cell collide with radicals such as hydrogen radicals introduced into the collision cell from the radical supply unit and are dissociated, generating multiple product ions. The rear-stage quadrupole mass filter selectively passes only ions having a predetermined m / z value among the product ions, and the ions that pass through the rear-stage quadrupole mass filter are detected by the ion detector.

[0004] A typical connection mechanism between the collision cell and the radical supplier in the above-mentioned tandem quadrupole mass spectrometer will be described with reference to Figures 10 and 11. The radical supplier 10 includes a housing 11 and a first pipe 12, which is a pipe through which radicals pass when supplied from inside the housing 11 to inside the collision cell 20. The first pipe 12 is a thin glass tube that penetrates the outer wall of the housing 11, with one end protruding outside the housing 11. The collision cell 20 includes a housing 21 and a second pipe 22, which is a pipe that protrudes from the peripheral wall of the housing 21. The second pipe 22 is a cylindrical metal tube with an inner diameter slightly larger than the outer diameter of the first pipe 12, and its internal space is connected to the internal space of the collision cell 20. 10, a wall surface 30 of the vacuum chamber exists between the collision cell 20 and the radical supply unit 10, and the first pipe 12 of the radical supply unit 10 is inserted into the second pipe 22 of the collision cell 20 through a through-hole 31 provided in the wall surface 30 of the vacuum chamber. As shown in Fig. 11, a plurality of O-rings 23 are arranged on the inner peripheral surface of the second pipe 22 at intervals in the axial direction, and these O-rings 23 seal the gap between the outer peripheral surface of the first pipe 12 and the inner peripheral surface of the second pipe 22. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 240908 Summary of the Invention [Problem to be solved by the invention]

[0006] In a tandem quadrupole mass spectrometer having the above configuration, when performing maintenance work on the collision cell 20 or the radical supply unit 10, it is necessary to disconnect the first pipe 12 from the second pipe 22 and remove the radical supply unit 10 from the collision cell 20. However, as described above, an axial seal (i.e., a seal between the circumferential surfaces of the cylindrical or tubular bodies) using the O-ring 23 is provided between the first pipe 12 and the second pipe 22. Therefore, when inserting or removing the first pipe 12 into or from the second pipe 22, it is necessary to move the first pipe 12 accurately and carefully in its axial direction so as not to damage the first pipe 12 due to friction between the outer circumferential surface of the first pipe 12 and the O-ring 23. Therefore, there is a problem in that the work of disconnecting and reconnecting the first pipe 12 and the second pipe 22 takes time and effort.

[0007] Although the above example cites a case in which the first pipe 12 is made of glass, even if the first pipe 12 is made of a material other than glass (e.g., metal or ceramic), when inserting or removing the first pipe 12 from the second pipe 22, the first pipe 12 may bend or break if the first pipe 12 is not moved accurately in its axial direction. Therefore, similar to the above, there is a problem that the connection and disconnection of the first pipe 12 and the second pipe 22 takes time and effort. Furthermore, this problem is not limited to the connection between the first pipe 12 of the radical supplier 10 and the second pipe 22 of the collision cell 20 in the tandem quadrupole mass spectrometer described above, but is common to pipe connection mechanisms that connect pipes through which fluids such as gases or liquids flow, and in which one end of a pipe is inserted into the end of another pipe to provide a liquid-tight or airtight connection.

[0008] The present invention has been made in consideration of the above points, and its purpose is to provide a pipe connection mechanism in which one end of a pipe is inserted into the end of another pipe to connect them in a liquid-tight or airtight manner, so that the pipe can be easily inserted and removed from the other pipe. [Means for solving the problem]

[0009] The piping connection mechanism according to the present invention, which is made to solve the above problems, comprises: A mechanism for connecting a first pipe and a second pipe having an inner diameter larger than an outer diameter of the first pipe, a first connecting member including a first cylindrical portion through which the first pipe is inserted and a first opposing surface that is a surface perpendicular to the axis of the first cylindrical portion; a second connecting member including a second cylindrical portion into which one end of the second pipe is inserted and a second opposing surface that is a surface perpendicular to the axis of the second cylindrical portion; When one end of the first pipe is inserted into the one end of the second pipe, the first opposing surface and the second opposing surface face each other, a ring-shaped first seal member that seals between an outer peripheral surface of the first pipe and an inner peripheral surface of the first cylindrical portion; a ring-shaped second seal member that seals between an outer peripheral surface of the second pipe and an inner peripheral surface of the second cylindrical portion; a ring-shaped third seal member sandwiched and compressed between the first opposing surface and the second opposing surface; It has the following characteristics. [Effects of the Invention]

[0010] According to the pipe connection mechanism of the present invention having the above configuration, the first pipe can be easily inserted into and removed from the second pipe. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing the configuration of the main parts of a tandem quadrupole mass spectrometer equipped with a piping connection mechanism according to an embodiment of the present invention. [Figure 2] FIG. 2 is an exploded perspective cross-sectional view showing the configuration of a collision cell, a vacuum chamber door, and a radical supply unit in the embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing the configuration of a first connecting member in this embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing the configuration of a second connecting member in this embodiment. [Figure 5] FIG. 3 is a cross-sectional view showing the configuration of a door of a vacuum chamber in the embodiment. [Figure 6] FIG. 2 is an enlarged cross-sectional view showing a state before the collision cell is connected to the radical supply unit in the same embodiment. [Figure 7] FIG. 2 is an enlarged cross-sectional view showing a state in which the collision cell is connected to a radical supply unit in the embodiment. [Figure 8] FIG. 10 is an enlarged cross-sectional view showing another configuration example of a pipe connection mechanism according to the present invention. [Figure 9] FIG. 10 is an enlarged cross-sectional view showing yet another configuration example of the pipe connection mechanism according to the present invention. [Figure 10] FIG. 1 is a perspective view showing the configuration of a collision cell, a wall surface of a vacuum chamber, and a radical supplier in a conventional tandem quadrupole mass spectrometer. [Figure 11] FIG. 2 is an enlarged cross-sectional view showing a typical piping connection mechanism in the conventional tandem quadrupole mass spectrometer. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0013] FIG. 1 is a schematic diagram showing the main components of a tandem quadrupole mass spectrometer (hereinafter simply referred to as a "mass spectrometer") equipped with a piping connection mechanism according to this embodiment. The mass spectrometer according to this embodiment has a vacuum chamber 110 that is evacuated by a vacuum pump (not shown). Inside the vacuum chamber 110, there are arranged an ion source 171 that ionizes compounds in a sample, a front-stage quadrupole mass filter 172 that selectively passes ions having a specific m / z value as precursor ions, a collision cell 120 (corresponding to the second unit in this invention) that generates various product ions by causing the precursor ions to collide with radicals and dissociate them, a rear-stage quadrupole mass filter 173 that selectively passes ions having a specific m / z value among the product ions, and a detector 174 that detects ions that have passed through the rear-stage quadrupole mass filter 173. Note that the ion source 171 may also be provided outside the vacuum chamber 110.

[0014] The collision cell 120 is a hollow structure with a relatively high airtightness, and inside thereof is disposed a quadrupole (or higher multipole) ion guide 121 that focuses and transports ions. The collision cell 120 is provided with a radical supply unit 130 (corresponding to the first unit in the present invention) for generating radicals (i.e., atoms, molecules, or ions having unpaired electrons) and supplying them to the collision cell 120. The radical supply unit 130 is disposed outside the vacuum chamber 110, and is connected to the collision cell 120 by a pipe that penetrates the wall surface of the vacuum chamber 110.

[0015] The piping includes a glass tube 131 (corresponding to the first piping in the present invention) for deriving radicals such as hydrogen radicals or hydroxyl radicals from the radical supply unit 130, and a tubular glass tube insertion unit 124 (corresponding to the second piping in the present invention) provided in the collision cell 120. Hereinafter, the configurations of the radical supply unit 130 and the collision cell 120, and the connection mechanism between the glass tube 131 and the glass tube insertion unit 124 will be described with reference to FIGS.

[0016] FIG. 2 is an exploded perspective view showing the radical supply unit 130, the collision cell 120, and a portion of the outer wall of the vacuum chamber 110 located between them. In this embodiment, the door of the vacuum chamber 110 (hereinafter referred to as the vacuum chamber door 111) is cut along a plane including the central axis A of the glass tube 131 provided in the radical supply unit 130. In this embodiment, the vacuum chamber door 111 corresponds to the plate-like component of the present invention. As described above, the ion guide 121 is disposed inside the collision cell 120, but is not shown in FIG. 2 for simplification. FIG. 3 is a cross-sectional view showing the configuration of a first connecting member 140 (described later), and FIG. 4 is a cross-sectional view showing the configuration of a second connecting member 150 (described later). FIG. 5 is a cross-sectional view showing the configuration of the vacuum chamber door 111. FIG. 6 is an enlarged cross-sectional view showing the radical supply unit 130 and the collision cell 120 before they are connected (or when they are disconnected), and FIG. 7 is an enlarged cross-sectional view showing the connected state.

[0017] The radical supply unit 130 generates radicals from a predetermined type of raw material gas using high-frequency plasma and supplies the radicals to the collision cell 120. The radical supply unit 130 includes a hollow cylindrical housing (hereinafter referred to as the radical supply unit housing 132) having a radical generation chamber (not shown) formed therein, a vacuum pump (not shown) for evacuating the radical generation chamber, a raw material gas supply source (not shown) for introducing a raw material gas into the radical generation chamber, a high-frequency plasma source (not shown) for supplying microwaves to generate a vacuum discharge in the radical generation chamber, and a glass tube 131 for guiding the radicals generated in the radical generation chamber to the outside. The radical supply unit housing 132 includes a cylindrical main body 133 having at least one open end and a mounting flange 134 extending radially outward from the one end of the main body 133, and a first connecting member 140 is attached to the opening at the one end of the main body 133.

[0018] The first connecting member 140 includes a first cylindrical portion 142 through which the glass tube 131 is inserted, and a first flange 141 provided on the outer periphery of the first cylindrical portion 142. One end of the first cylindrical portion 142 protrudes from one surface of the first flange 141, and the other end protrudes from the other surface of the first flange 141. The first connecting member 140 is attached to the main body portion 133 by fitting the first flange 141 into an opening at the one end of the main body portion 133. That is, in this embodiment, the first flange 141 of the first connecting member 140 also serves as a part of the radical supply unit housing 132. The first flange 141 is joined to the main body portion 133 by welding, screwing, or the like. Hereinafter, the region of the first cylindrical portion 142 that protrudes outward from the radical supply unit housing 132 will be referred to as the "distal region 144," and the region located inside the radical supply unit housing 132 will be referred to as the "proximal region 143." The tip-side region 144 further includes a second cylindrical portion insertion portion 145 having a relatively large outer diameter, and a glass tube covering portion 146 (corresponding to the first piping covering portion in the present invention) having a relatively small outer diameter. The second cylindrical portion insertion portion 145 is located on the base-end side (the side closer to the first flange 141) of the tip-side region 144, and has an outer diameter smaller than the inner diameter of a second cylindrical portion 152 (described later) and larger than the inner diameter of the glass tube insertion portion 124. The glass tube covering portion 146 is located on the tip-side side of the tip-side region 144 (the side farther from the first flange 141), and has an outer diameter slightly smaller than the inner diameter of the glass tube insertion portion 124.

[0019] The glass tube 131 is inserted into the first cylindrical portion 142 of the first connecting member 140 so that one end thereof protrudes over a predetermined length from the radical supply unit housing 132 (i.e., from the first flange 141), and more than half (preferably more than two-thirds) of the protruding area is covered by the glass tube covering portion 146 of the first connecting member 140. An annular first groove portion 147 is formed in the inner circumferential surface of the base-end side region 143 of the first cylindrical portion 142. An annular first seal member 161 is housed in the first groove portion 147, and this first seal member 161 seals the gap between the outer circumferential surface of the glass tube 131 and the inner circumferential surface of the first cylindrical portion 142.

[0020] The collision cell 120 comprises a hollow cylindrical housing (hereinafter referred to as the collision cell housing 122) and a cylindrical glass tube insertion portion 124 that protrudes outward from the circumferential surface of the collision cell housing 122. A through-hole 123 is provided in the circumferential surface of the collision cell housing 122 at a position corresponding to the glass tube insertion portion 124, and the internal space of the glass tube insertion portion 124 communicates with the internal space of the collision cell housing 122 via the through-hole 123. The glass tube insertion portion 124 comprises a cylindrical tube 125 having an inner diameter slightly larger than the outer diameter of the first cylindrical portion 142 of the first connecting member 140, and a mounting flange 126 provided at one end of the tube 125, and is attached to the collision cell housing 122 by fixing the mounting flange 126 to the circumferential wall of the collision cell housing 122 with screws or the like.

[0021] The vacuum chamber door 111, located between the radical supply part 130 and the collision cell 120, has a recess 112 that is circular in plan view on the surface (i.e., the outer surface) facing the radical supply part 130, and a piping insertion hole 113, which is a through-hole, is bored in the center of the recess 112. A second connecting member 150, which is circular in plan view, is fitted into the recess 112.

[0022] The second connecting member 150 includes a cylindrical second tube portion 152 and an annular second flange 151 extending outward from a longitudinal (axial) intermediate portion of the second tube portion 152. The second tube portion 152 has an inner diameter slightly larger than the outer diameter of the glass tube insertion portion 124. The outer diameter of the second tube portion 152 is relatively larger on one side of the second flange 151 and relatively smaller on the other side. Hereinafter, the region of the second tube portion 152 with the relatively larger outer diameter will be referred to as the large-diameter portion 153, and the region with the relatively smaller outer diameter will be referred to as the small-diameter portion 154. The outer diameter of the second flange 151 is larger than the inner diameter of the piping insertion hole 113 and smaller than the inner diameter of the recess 112, and the outer diameter of the small-diameter portion 154 is slightly smaller than the inner diameter of the piping insertion hole 113.

[0023] An annular second groove 155 is formed in the inner peripheral surface of the small diameter portion 154, and an annular second seal member 162 is housed here. An annular third groove 156 is formed in the end face of the large diameter portion 153, and an annular third seal member 163 is housed here. In addition, an annular fourth groove 114 is formed in the bottom surface of the recess 112 provided in the vacuum chamber door 111 so as to surround the piping insertion hole 113, and an annular fourth seal member 164 is housed here.

[0024] The glass tube 131 can be made of, for example, borosilicate glass such as Pyrex (registered trademark) glass, or quartz glass. The first seal member 161, the second seal member 162, the third seal member 163, and the fourth seal member 164 can be suitably made of, for example, O-rings made of elastomers such as nitrile rubber, silicone rubber, or fluororubber. Of the components shown in FIG. 2 , those other than the glass tube 131, the first seal member 161, the second seal member 162, the third seal member 163, and the fourth seal member 164, such as the first connection member 140, the second connection member 150, and the glass tube insertion portion 124, can typically be made of metal such as stainless steel, but can also be made of other materials, such as ceramics or hard resin.

[0025] The glass tube 131 is always attached to the first connecting member 140 in a state where it is inserted through the first cylindrical portion 142, and after the radical supply unit 130 is assembled, it is not, in principle, inserted into or removed from the first connecting member 140. In addition, the glass tube insertion portion 124 is also always fixed to the collision cell housing 122. The procedure for assembling the collision cell 120 and the radical supply unit 130 to the vacuum chamber 110 from this state (i.e., the state shown in FIG. 2) will be described.

[0026] First, the tip of the glass tube insertion portion 124 is inserted into the piping insertion hole 113 from the inner surface of the vacuum chamber door 111 (i.e., the surface facing the inside of the vacuum chamber 110), and the small diameter portion 154 of the second cylindrical portion 152 of the second connecting member 150 is inserted into the piping insertion hole 113 from the outer surface of the vacuum chamber door 111. Note that a second seal member 162, a third seal member 163, and a fourth seal member 164 are attached in advance to the second groove portion 155, the third groove portion 156, and the fourth groove portion 114, respectively.

[0027] As a result of the above, the small diameter portion 154 of the second connecting member 150 is accommodated in the piping insertion hole 113, the second flange 151 and the large diameter portion 153 are accommodated in the recess 112 of the vacuum chamber door 111, and the tip of the glass tube insertion portion 124 is inserted into the second cylindrical portion 152 of the second connecting member 150. As a result, the second seal member 162 attached to the second groove portion 155 of the second connecting member 150 seals the gap between the outer peripheral surface of the glass tube insertion portion 124 and the inner peripheral surface of the second cylindrical portion 152 of the second connecting member 150, and the collision cell 120 is fixed to the vacuum chamber 110 (FIG. 6).

[0028] Next, with the tip of the glass tube 131 facing the outer surface of the vacuum chamber door 111, the radical supply unit 130 is brought close to the vacuum chamber door 111, whereby the glass tube 131 and the glass tube covering portion 146 of the first connecting member 140 are inserted into the glass tube insertion portion 124 (FIG. 7). At this time, the second cylindrical portion insertion portion 145 of the first connecting member 140 is fitted into the upper end of the second cylindrical portion 152 provided on the second connecting member 150. Then, the mounting flange 134 is fixed to the vacuum chamber door 111 by threading a screw 165 into the screw hole 135 provided in the mounting flange 134 of the radical supply unit casing 132 and the screw hole 115 provided in the vacuum chamber door 111.

[0029] By fastening the mounting flange 134 of the radical supplier 130 to the vacuum chamber door 111 as described above, one surface 148 (corresponding to the first opposing surface in this invention) of the first flange 141 of the first connecting member 140 is pressed against an end surface 157 (corresponding to the second opposing surface in this invention) of the large diameter portion 153 of the second connecting member 150, and the second flange 151 of the second connecting member 150 is pressed against the bottom surface of the recess 112 of the vacuum chamber door 111. As a result, the third seal member 163 is squeezed between the first flange 141 of the first connecting member 140 and the end surface 157 of the large diameter portion 153 of the second connecting member 150 to seal the space therebetween, and the fourth seal member 164 is squeezed between the second flange 151 of the second connecting member 150 and the bottom surface of the recess 112 of the vacuum chamber door 111 to seal the space therebetween. As described above, the gap between the outer circumferential surface of the glass tube 131 and the inner circumferential surface of the first cylindrical portion 142 of the first connecting member 140 is sealed by the first sealing member 161, and the gap between the outer circumferential surface of the glass tube insertion portion 124 and the inner circumferential surface of the second cylindrical portion 152 of the second connecting member 150 is sealed by the second sealing member 162. Therefore, according to the above-described connection mechanism, the radical supply unit 130 can be connected to the collision cell 120 in the vacuum chamber 110 without causing leakage of radicals or deterioration of the vacuum degree of the vacuum chamber 110.

[0030] When the radical supplier 130 and the collision cell 120 are removed from the vacuum chamber 110, for example, when performing maintenance on the mass spectrometer, the above steps are reversed.

[0031] As described above, in the mass spectrometer according to this embodiment, the surfaces that move relative to each other when the glass tube 131 is inserted into or removed from the glass tube insertion section 124 are sealed by the third seal member 163, which is a surface seal (a seal between flat surfaces), and no axial seal (a seal between the circumferential surfaces of a cylinder or tube) is provided to seal between the outer circumferential surface of the glass tube 131 and the inner circumferential surface of the glass tube insertion section 124 as in the conventional case. Therefore, there is no risk of the glass tube 131 being damaged by friction with the axial seal when the glass tube 131 is inserted into or removed from the glass tube insertion section 124. Furthermore, because such friction does not occur, it is not necessary to precisely move the glass tube 131 in its axial direction when inserting or removing it, and this makes it easy to disconnect and reconnect the glass tube 131 and the glass tube insertion section 124. Furthermore, since most of the area of ​​the glass tube 131 that is inserted into the glass tube insertion portion 124 is protected by the glass tube covering portion 146 of the first connecting member 140, it is possible to prevent the glass tube 131 from being damaged by an impact applied to the outer surface of the glass tube 131 when inserting or removing the glass tube 131.

[0032] Although specific examples of the form for carrying out the present invention have been described above, the present invention is not limited to the above-described embodiments, and appropriate modifications are permitted within the scope of the spirit of the present invention.

[0033] For example, in the above embodiment, the third seal member 163 is configured to be attached to the second connecting member 150, but instead, the third seal member 163 may be configured to be attached to the first connecting member 140. In that case, an annular groove is provided on the surface of the first flange 141 that faces the second connecting member 150 (the lower surface in FIG. 6), and the third seal member 163 is fitted into the groove.

[0034] In the above embodiment, the first connecting member 140 is configured to have a glass tube covering portion 146, but the glass tube covering portion 146 is not necessarily provided. An example of a configuration in which the glass tube covering portion 146 is not provided is shown in Fig. 8. In this figure, components that are the same as or correspond to those shown in Figs. 2 to 7 are assigned reference numerals with the same last two digits.

[0035] Furthermore, in the above embodiment, the glass tube 131 corresponds to the first piping in the present invention, but the first piping in the present invention does not necessarily have to be made of glass, and may be made of other materials, such as metal or ceramics.

[0036] Furthermore, the application of the piping connection mechanism of the present invention is not limited to the connection between the collision cell 120 and the radical supply section 130 in the tandem quadrupole mass spectrometer described above, but may be applied to any connection section of any structure as long as one end of a pipe (first pipe) is inserted into the end of another pipe (second pipe) to form a liquid-tight or airtight connection.

[0037] Furthermore, in the above embodiment, the second connecting member 150 is fitted into and supported in a recess 112 provided in a plate-like member (specifically, the vacuum chamber door 111), and the radical supply unit housing 132, to which the first connecting member 140 is fixed, is screwed to the plate-like member, thereby sandwiching the third seal member 163 between the opposing surfaces of the first connecting member 140 and the second connecting member 150. However, the piping connection mechanism according to the present invention does not necessarily have to include the plate-like member. An example of a configuration in which a plate-like member is not provided is shown in FIG. 9. Note that in this figure, components corresponding to those shown in FIGS. 2 to 7 are assigned reference numerals with the same last two digits. In the example shown in the figure, first connecting member 340, through which first pipe 331 is inserted, and second connecting member 350, through which second pipe 324 is inserted, do not respectively include first flange 141 and second flange 151 as described above, and a third seal member 363 is sandwiched between one end face of first cylindrical portion 342 (corresponding to the first opposing surface in the present invention) and one end face of second cylindrical portion 352 (corresponding to the second opposing surface in the present invention). Furthermore, first connecting member 340 and second connecting member 350 are fixed to each other by detachable fixing means such as screws 366. Note that, in addition to screws 366, the detachable fixing means may also include engagement by a predetermined engaging means or fitting by a predetermined fitting means.

[0038] [Aspect] It will be apparent to those skilled in the art that the above-described exemplary embodiments are examples of the following aspects.

[0039] (Item 1) A pipe connection mechanism according to one aspect of the present invention is a mechanism for connecting a first pipe to a second pipe having an inner diameter larger than an outer diameter of the first pipe, a first connecting member including a first cylindrical portion through which the first pipe is inserted and a first opposing surface that is a surface perpendicular to the axis of the first cylindrical portion; a second connecting member including a second cylindrical portion into which one end of the second pipe is inserted and a second opposing surface that is a surface perpendicular to the axis of the second cylindrical portion; When one end of the first pipe is inserted into the one end of the second pipe, the first opposing surface and the second opposing surface face each other, a ring-shaped first seal member that seals between an outer peripheral surface of the first pipe and an inner peripheral surface of the first cylindrical portion; a ring-shaped second seal member that seals between an outer peripheral surface of the second pipe and an inner peripheral surface of the second cylindrical portion; a ring-shaped third seal member sandwiched and compressed between the first opposing surface and the second opposing surface; It has the following characteristics.

[0040] According to the pipe connection mechanism of paragraph 1, when the first pipe is inserted into or removed from the second pipe, friction due to the shaft seal is not applied to the outer surface of the first pipe, which makes it easier to connect and disconnect the first pipe and the second pipe, and also prevents damage to the first pipe.

[0041] (2) The pipe connection mechanism according to paragraph 2 is a pipe connection mechanism according to paragraph 1, The first connecting member further comprises: a flange provided on the outer periphery of the first cylindrical portion; a first pipe covering portion in a region on the one end side of the first cylindrical portion and having an outer diameter smaller than an inner diameter of the second cylindrical portion; Equipped with the first opposing surface is one surface of the flange, The first pipe covering portion is inserted into the one end of the second pipe together with the one end of the first pipe.

[0042] According to the pipe connection mechanism of paragraph 2, at least a portion of the area of ​​the first pipe that is inserted into the second pipe is protected by the first pipe covering portion, so that it is possible to prevent the first pipe from being damaged by an impact applied to the outer surface of the first pipe when, for example, inserting or removing the first pipe into or from the second pipe.

[0043] (Item 3) The structure according to item 3 is a structure including the piping connection mechanism according to item 1 or 2, a first unit having a first housing and the first piping, the first piping protruding from the first housing; a second unit having a second housing and the second piping, the second piping protruding from the second housing; a plate-like part having a through hole into which the second cylindrical part is fitted and supporting the second connecting member; and The first unit and the second unit are disposed opposite each other with the plate-like component interposed therebetween.

[0044] According to the structure of the third aspect, the first unit and the second unit can be connected to each other via the second connecting member supported by the plate-like part.

[0045] (Item 4) A mass spectrometer according to item 4 is a mass spectrometer equipped with the structure according to item 3, the second unit is a collision cell that dissociates ions; the first unit is a radical supplier that supplies radicals to the collision cell, The plate-like component is a part of the outer wall of the vacuum chamber that houses the collision cell.

[0046] According to the mass spectrometer of the fourth aspect, the radical supply unit can be connected to the collision cell in the vacuum chamber without causing leakage of radicals or deterioration of the vacuum level of the vacuum chamber, and it is possible to easily connect and disconnect the first pipe and the second pipe during maintenance of the device, for example. [Explanation of symbols]

[0047] 110...Vacuum chamber 111...Vacuum chamber door 112...recess 113...Pipe insertion hole 120...Collision cell 122...Collision cell housing 124...Glass tube insertion part 130... Radical supply unit 131...Glass tube 132... Radical supply unit housing 133...Main body 134...Mounting flange 140...First connecting member 141...First flange 142...First cylindrical part 143...Proximal region 144…Tip side area 145...Second tube insertion part 146...Glass tube covering part 150...Second connecting member 151...Second flange 152...Second cylinder part 153...Large diameter section 154...Small diameter section 161...first seal member 162...Second seal member 163...Third seal member 164...Fourth seal member 165...Screw

Claims

1. A mechanism for connecting a first pipe and a second pipe having an inner diameter larger than an outer diameter of the first pipe, a first connecting member including a first cylindrical portion through which the first pipe is inserted and a first opposing surface that is a surface perpendicular to the axis of the first cylindrical portion; a second connecting member including a second cylindrical portion into which one end of the second pipe is inserted and a second opposing surface that is a surface perpendicular to the axis of the second cylindrical portion; When one end of the first pipe is inserted into the one end of the second pipe, the first opposing surface and the second opposing surface face each other, a ring-shaped first seal member that seals between an outer peripheral surface of the first pipe and an inner peripheral surface of the first cylindrical portion; a ring-shaped second seal member that seals between an outer peripheral surface of the second pipe and an inner peripheral surface of the second cylindrical portion; a ring-shaped third seal member sandwiched and pressed between the first opposing surface and the second opposing surface; A piping connection mechanism having:

2. The first connecting member further comprises: a flange provided on an outer periphery of the first cylindrical portion; a first pipe covering portion in a region on the one end side of the first cylindrical portion, the first pipe covering portion having an outer diameter smaller than an inner diameter of the second cylindrical portion; Equipped with the first opposing surface is one surface of the flange, The pipe connection mechanism according to claim 1 , wherein the first pipe covering portion is inserted into the one end of the second pipe together with the one end of the first pipe.

3. A structure including the piping connection mechanism according to claim 1 or 2, a first unit having a first housing and the first piping, the first piping protruding from the first housing; a second unit having a second housing and the second piping, the second piping protruding from the second housing; a plate-like component having a through hole into which the second cylindrical portion is fitted and supporting the second connecting member; and A structure in which the first unit and the second unit are disposed opposite each other with the plate-like component interposed therebetween.

4. A mass spectrometer comprising the structure of claim 3, the second unit is a collision cell that dissociates ions; the first unit is a radical supplier that supplies radicals to the collision cell, The plate-like component is a part of the outer wall of a vacuum chamber that houses the collision cell. Mass spectrometer.

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