Mass analysis device

Abstract

The present invention relates to a mass spectrometer, wherein a door (4) comprises: a closing portion (41) that closes an opening (302) in a closed state; and a holding portion (42) that holds the closing portion (41) and is connected to a hinge portion (5). The closing portion (41) is configured to be connected to the holding portion (42) on the side opposite to the hinge portion (5) and to be separable from the holding portion (42) on the hinge portion (5) side. When the door (4) is rotated from an open state to a closed state, the closing portion (41) is configured to contact the peripheral edge of the opening (302) on the side opposite to the hinge portion (5) before contacting the peripheral edge of the opening (302) on the side opposite to the hinge portion (5).

Description

Technical Field

[0001] The present invention relates to a mass analysis device. Background Art

[0002] In a mass spectrometer, a sample can be analyzed in a vacuum chamber that is set to a vacuum state. The vacuum chamber can be opened and closed by a door, and the vacuum chamber is exposed by opening the door during maintenance or the like (for example, see Patent Document 1 below).

[0003] Figures 4A to 4C This is a schematic cross-sectional view showing a configuration example of a conventional opening and closing mechanism of the door 102 . Figure 4A The situation when the door 102 is in the open state is shown. Figure 4B The door 102 is shown in the middle of rotating from the open state to the closed state. Figure 4C The door 102 is shown in a closed state. In this opening and closing mechanism, an opening 111 formed in the housing 101 is configured to be openable and closable by the door 102. The door 102 is rotatably supported by a hinge portion 103 extending in the vertical direction.

[0004] Door 102 includes a closing portion 121 and a retaining portion 122 that retains closing portion 121. Hinge portion 103 rotatably supports one end of retaining portion 122. Closing portion 121 is secured to retaining portion 122 with screws 123 at both the end on the hinge portion 103 side and the end opposite the hinge portion 103 side. This ensures that closing portion 121 is always secured to retaining portion 122 with its entire surface in close contact.

[0005] The sealing portion 121 is provided with an O-ring 124 on the surface opposite to the holding portion 122. Figure 4A The open state shown gradually turns to the closed state, then Figure 4B As shown, first, the O-ring 124 on the hinge portion 103 side contacts the peripheral edge of the opening 111. In this state, the O-ring 124 on the side opposite to the hinge portion 103 side separates from the peripheral edge of the opening 111 due to the repulsive force of the O-ring 124.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-346703 Summary of the Invention

[0009] Technical problem to be solved by the invention

[0010] exist Figure 4BIn the state of , when the vacuum chamber 110 formed in the housing 101 is to be in a vacuum state, air enters the vacuum chamber 110 from the gap 104 formed between the O-ring 124 and the peripheral edge of the opening 111, making it difficult to keep the vacuum chamber 110 in a vacuum state. Therefore, it is necessary to overcome the repulsive force of the O-ring 124 to apply an external force to the door 102, and Figure 4C After the state shown, the vacuum chamber 110 is evacuated. As a mechanism for applying an external force to the door 102, for example, a screw (not shown) or the like can be used.

[0011] The present invention has been made in view of the above-mentioned actual situation, and an object thereof is to provide a mass spectrometer capable of sealing an opening communicating with a vacuum chamber by a simpler operation.

[0012] Solutions for solving the above technical problems

[0013] The first embodiment of the present invention is a mass spectrometer comprising a housing, a door, and a hinge. The housing is internally formed with a vacuum chamber that is set to a vacuum state during analysis, and has an opening connected to the vacuum chamber. The door opens and closes the opening. The hinge is configured to support the door so that it can rotate between an open state and a closed state. The door has a closing portion that closes the opening in a closed state, and a holding portion that holds the closing portion and is connected to the hinge. The closing portion is configured to be connected to the holding portion on the side opposite to the hinge and to be separable from the holding portion on the hinge. When the door is rotated from an open state to a closed state, the closing portion is configured to be in contact with the peripheral portion of the opening on the side opposite to the hinge before the closing portion contacts the peripheral portion of the opening on the hinge.

[0014] Effects of the Invention

[0015] According to the first embodiment of the present invention, by rotating the door from an open state to a closed state, the sealing portion can be brought into contact with the peripheral edge of the opening on the side opposite the hinge. Then, by moving the sealing portion away from the retaining portion on the hinge side and closer to the opening, the sealing portion can be brought into close contact with the peripheral edge of the opening on the hinge side. This makes it possible to seal the opening connected to the vacuum chamber with a simpler operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram showing a configuration example of a mass spectrometer.

[0017] Figure 2 This is a schematic side view for explaining the structure around the door, showing a state where the door is opened.

[0018] Figure 3AThis is a schematic cross-sectional view for explaining the opening and closing operation of the door, and shows a state before the sealing member comes into contact with the peripheral edge of the opening.

[0019] Figure 3B This is a schematic cross-sectional view for explaining the opening and closing operation of the door, and shows a state in which the side of the sealing member opposite to the hinge portion is in contact with the peripheral edge of the opening.

[0020] Figure 3C This is a schematic cross-sectional view for explaining the opening and closing operation of the door, and shows a state in which the side of the sealing member opposite to the hinge portion is compressed relative to the peripheral edge of the opening.

[0021] Figure 3D This is a schematic cross-sectional view for explaining the opening and closing operation of the door, and shows a state in which the entire sealing member is compressed relative to the peripheral edge of the opening.

[0022] Figure 4A This is a schematic cross-sectional view showing a configuration example of a conventional door opening and closing mechanism, and shows the door in an open state.

[0023] Figure 4B This is a schematic cross-sectional view showing a configuration example of a conventional door opening and closing mechanism, and shows a state in which a door is in the process of rotating from an open state to a closed state.

[0024] Figure 4C This is a schematic cross-sectional view showing a configuration example of a conventional door opening and closing mechanism, and shows the door in a closed state. DETAILED DESCRIPTION

[0025] 1. Overall structure of the mass analyzer

[0026] Figure 1 It is a schematic diagram showing a configuration example of the mass spectrometer 1 . Figure 1 The mass spectrometer 1 shown is a gas chromatograph-mass spectrometer that performs mass analysis on components in a sample separated by gas chromatography. The mass spectrometer 1 includes a gas chromatograph unit 2 and a mass spectrometer unit 3 .

[0027] The gas chromatograph 2 includes a chromatographic column (not shown). During analysis, a carrier gas is introduced into the column along with the sample. As the sample passes through the column, its components are separated. The components of the sample separated by the column are sequentially supplied to the mass spectrometer 3. The carrier gas is, for example, an inert gas such as nitrogen or helium, but is not limited thereto and may also be other gases such as hydrogen.

[0028] The mass spectrometer 3 includes a hollow housing 300. An ionization chamber 31, a first vacuum chamber 32, and a second vacuum chamber 33 are formed within the housing 300. The mass spectrometer 3 includes a vacuum pump (not shown). During analysis, the vacuum pump is driven to evacuate the ionization chamber 31, the first vacuum chamber 32, and the second vacuum chamber 33. The ionization chamber 31, the first vacuum chamber 32, and the second vacuum chamber 33 are interconnected vacuum chambers 30, and the vacuum level is gradually increased in this order.

[0029] A carrier gas is supplied from the gas chromatograph 2 to the ionization chamber 31 along with each sample component. Each sample component is ionized within the ionization chamber 31. Examples of ionization methods include, but are not limited to, EI (Electron Ionization), PCI (Positive Chemical Ionization), and NCI (Negative Chemical Ionization).

[0030] The first vacuum chamber 32 communicates with the ionization chamber 31 via an opening 321. Ions generated in the ionization chamber 31 are introduced into the first vacuum chamber 32 via the opening 321. The ions introduced into the first vacuum chamber 32 are converged by the ion guide 322 and flow into the second vacuum chamber 33.

[0031] The second vacuum chamber 33 is provided with, for example, a quadrupole mass filter 331 and a detector 332. Ions flowing from the first vacuum chamber 32 into the second vacuum chamber 33 are separated by mass-to-charge ratio by the quadrupole mass filter 331, and only ions with a specific mass-to-charge ratio pass through the quadrupole mass filter 331. The ions that have passed through the quadrupole mass filter 331 are incident on the detector 332. The ion detector 332 outputs a current corresponding to the number of ions that have arrived as a detection signal.

[0032] The mass spectrometer 3 is provided with a door 4 for opening and closing the vacuum chamber 30. In this example, the door 4 is attached to a portion of a wall 301 of the housing 300 that defines the ionization chamber 31. However, the door 4 may be provided on a wall of the vacuum chamber 30 other than the plasma chamber 31, such as the first vacuum chamber 32 or the second vacuum chamber 33.

[0033] In the following description, the side of the door 4 in the housing 300 is referred to as the front, and the side opposite to the door 4 is referred to as the rear. The wall 301 on which the door 4 is mounted is inclined relative to the vertical direction. Specifically, the lower portion of the wall 301 is located further forward than the upper portion, so that the wall 301 is inclined more upward than the vertical direction. The inclination angle of the wall 301 relative to the vertical direction can be arbitrarily set within a range greater than 0° and less than 90°, for example. This configuration allows the deadweight of the door 4 to act on the wall 301 of the housing 300 when the door 4 is closed.

[0034] 2. The structure of the door perimeter

[0035] Figure 2 This is a schematic side view for explaining the structure around the door 4, showing a state where the door 4 is opened. Figure 2 As shown, door 4 is mounted so as to be openable and closable relative to housing 300, which has vacuum chamber 30 formed therein. Specifically, door 4 and housing 300 are connected via one or more hinges 5. Door 4 can be opened and closed by rotating about hinge 5. In this example, door 4 is rotatably supported by hinge 5 about an axis L that is inclined relative to the vertical direction. The upper side of axis L is inclined toward the side (rear) of housing 300.

[0036] An opening 302 is formed in the wall 301 of the housing 300 for inserting a hand or a tool during maintenance of the housing 300. The opening 302 is formed in a square shape with a horizontal width and a vertical width of about 10 to 20 cm, for example, but is not limited to this shape.

[0037] The opening 302 is connected to the vacuum chamber 30 and is opened and closed by the door 4. The door 4 is in the open state ( Figure 2 The door 4 is rotatably supported by the hinge portion 5 between an open state (shown in the figure) and a closed state in which the opening 302 is closed by the door 4. The end portion of the door 4 opposite the hinge portion 5 side is separated from the opening 302 in the open state and approaches the opening 302 in the closed state.

[0038] The door 4 includes a closing portion 41 and a holding portion 42. The closing portion 41 is a plate-shaped member having a planar shape larger than the opening 302 and closes the opening 302 in the closed state. The closing portion 41 can be formed of a material containing aluminum, for example, with a thickness of approximately 10 to 20 mm, but is not limited thereto.

[0039] A sealing member 43 is provided on the surface (inner surface 411) of the sealing portion 41 that faces the vacuum chamber 30 in the closed state. The sealing member 43 is formed of an annular O-ring that is larger than the opening 302 of the housing 300. When the door 4 is closed, the sealing member 43 contacts the periphery of the opening 302 in the housing 300.

[0040] In this example, the closed portion 41 is formed into a rectangular shape. The sealing member 43 is formed into a rectangular ring, the outer circumference of which is smaller than the outer circumference of the closed portion 41. The opening 302 of the housing 300 is formed into a rectangular shape that is smaller than the inner circumference of the sealing member 43. However, the opening 302 is not limited to a rectangular shape and may also be a circular shape or other shape. In addition, the closed portion 41 and the sealing member 43 may also adopt any shape to match the shape of the opening 302.

[0041] The holding portion 42 holds the closing portion 41. Specifically, the holding portion 42 is installed in a state where the surface (outer surface) on the opposite side of the sealing member 43 side of the closing portion 41 is in contact. The holding portion 42 is formed, for example, by a plate-shaped member thinner than the closing portion 41. The holding portion 42 can be formed, for example, by a material containing stainless steel or the like, with a thickness of about 1 to 2 mm, but is not limited thereto. The holding portion 42 has an extension portion 421 formed to extend toward the outside of the closing portion 41. The hinge portion 5 is connected to the extension portion 421 of the holding portion 42.

[0042] When the door 4 rotates from the open state to the closed state, the closing portion 41 is positioned relative to the opening 302 by the positioning mechanism 6. The positioning mechanism 6 includes, for example, a convex portion 61 and a concave portion 62. The convex portion 61 is formed at the periphery of the opening 302 in the housing 300. The concave portion 62 is formed in a region of the inner surface 411 of the closing portion 41 that is further outward than the sealing member 43.

[0043] More specifically, the protrusion 61 is formed at the end portion of the peripheral portion of the opening 302 on the side opposite to the hinge portion 5. The recess 62 is formed at the end portion of the inner surface 411 of the closing portion 41 on the side opposite to the hinge portion 5. The inner diameter of the recess 62 is slightly larger than the outer diameter of the protrusion 61. When the door 4 is rotated from the open state to the closed state, the protrusion 61 is inserted into the recess 62, thereby positioning the closing portion 41 on the side opposite to the hinge portion 5, so that the closing portion 41 is always in a constant position relative to the opening 302, thereby achieving the closed state.

[0044] The hinge portion 5 is attached to the housing 300 via a spacer 7. The spacer 7 is a plate-shaped member used to adjust the distance between the housing 300 and the hinge portion 5. By appropriately setting the thickness of the spacer 7, when the door 4 is rotated from the open state to the closed state, the sealing member 43 can contact the peripheral edge of the opening 302 on the side opposite the hinge portion 5 side before contacting the peripheral edge of the opening 302 on the hinge portion 5 side.

[0045] 3. Door opening and closing

[0046] Figures 3A to 3D This is a schematic cross-sectional view for explaining the opening and closing operation of the door 4 . Figure 3AThe state before the sealing member 43 comes into contact with the peripheral edge portion of the opening 302 is shown. Figure 3B The state in which the side of the sealing member 43 opposite to the hinge portion 5 side is in contact with the peripheral edge portion of the opening 302 is shown. Figure 3C The state in which the side of the sealing member 43 opposite to the hinge portion 5 side is compressed relative to the peripheral edge portion of the opening 302 is shown. Figure 3D The state in which the entire sealing member 43 is compressed relative to the peripheral edge portion of the opening 302 is shown.

[0047] like Figure 3A As shown, when the door 4 is closed until the inner surface 411 of the closing portion 41 is parallel to the peripheral edge of the opening 302, the sealing member 43 does not yet contact the peripheral edge of the opening 302. This is because the position of the hinge portion 5 relative to the housing 300 is adjusted by the spacer 7 described above. However, the position of the hinge portion 5 relative to the housing 300 can also be adjusted without using the spacer 7.

[0048] exist Figure 3A In the state, the closing portion 41 is positioned relative to the opening 302 by the positioning mechanism 6. When the door 4 is slightly rotated toward the closed state from this state, as shown in FIG. Figure 3B As shown in FIG. 1 , the end portion (second end portion 432) of the sealing member 43 on the side opposite to the hinge portion 5 contacts the peripheral portion of the opening 302 before the end portion (first end portion 431) on the hinge portion 5 side. In this state, the first end portion 431 of the sealing member 43 does not contact the peripheral portion of the opening 302. However, if the door 4 is slightly rotated toward the closed state to compress the second end portion 432 of the sealing member 43, as shown in FIG. Figure 3C As shown, the first end portion 431 of the sealing member 43 also contacts the peripheral edge portion of the opening 302 .

[0049] exist Figure 3C In this state, the entire circumference of the sealing member 43 is in contact with the peripheral edge of the opening 302. Therefore, if the vacuum pump is driven in this state, the vacuum chamber 30 can be evacuated. At this time, if the sealing portion 41 is completely fixed to the holding portion 42, the inner surface 411 of the sealing portion 41 is not parallel to the peripheral edge of the opening 302, resulting in a state in which the first end 431 of the sealing member 43 is not fully compressed and only the second end 432 of the sealing member 43 is compressed.

[0050] In order to prevent such uneven compression of the sealing member 43, in this embodiment, the closing portion 41 is connected to the holding portion 42 on the side opposite to the hinge portion 5, and is detachable from the holding portion 42 on the hinge portion 5 side. Specifically, the closing portion 41 is fixed to the holding portion 42 only at the end portion on the side opposite to the hinge portion 5.

[0051] In this example, a fastener 44 such as a screw connects the closing portion 41 and the holding portion 42 on the side opposite to the hinge portion 5, but the closing portion 41 and the holding portion 42 are not connected on the hinge portion 5 side. Therefore, when a force is applied to the end of the closing portion 41 on the hinge portion 5 side in a direction toward the housing 300, the closing portion 41 rotates toward the housing 300 around the fastener 44. Figure 3D As shown, a gap S is formed between the outer surface 412 of the closing portion 41 and the holding portion 42. At this time, the holding portion 42 bends near the connecting member 44 as the closing portion 41 rotates. The gap S is, for example, about 1 to 2 mm, but is not limited thereto.

[0052] In addition, the "opposite side of the hinge portion 5 side" refers to the side opposite to the hinge portion 5 side when viewed from the closing portion 41. For example, assuming that the closing portion 41 is configured not to be separated from the retaining portion 42, it is an area including the portion that initially contacts the peripheral portion of the opening 302 when the closing portion 41 rotates around the hinge portion 5. On the other hand, the "hinge portion 5 side" refers to the side of the hinge portion 5 when viewed from the closing portion 41. For example, it is an area closer to the hinge portion 5 than the area on the opposite side of the hinge portion 5 side, and it is an area including the portion that contacts the peripheral portion of the opening 302 when the closing portion 41 is separated from the retaining portion 42. For example, it may be that the width direction ( Figures 3A to 3D In the center of the left-right direction), the left side is the "hinge portion 5 side" and the right side is the "opposite side of the hinge portion 5 side".

[0053] In this embodiment, if Figure 2 As shown, since the axis L of the hinge portion 5 is inclined, Figure 3C From the state, the closing portion 41 can be rotated toward the housing 300 side with the connecting member 44 as the center by utilizing its own weight. Figure 3D As shown, the entire sealing member 43 (the first end portion 431 and the second end portion 432 ) is compressed and in close contact with the peripheral edge of the opening 302 , and the inner surface 411 of the closing portion 41 is parallel to the peripheral edge of the opening 302 .

[0054] 4. Modifications

[0055] The positioning mechanism 6 is not limited to a configuration comprising a convex portion 61 provided on the housing 300 and a concave portion 62 provided on the closing portion 41. For example, the convex portion 61 may be provided on the closing portion 41 and the concave portion 62 may be provided on the housing 300. In addition, the convex portion 61 or the concave portion 62 may be provided on a portion other than the closing portion 41 of the door 4 (e.g., the retaining portion 42). Furthermore, the configuration is not limited to the convex portion 61 and the concave portion 62, and a configuration in which other components such as magnets are used to position the door 4 may also be used.

[0056] The sealing member 43 is not limited to being provided on the closing portion 41 of the door 4, but may also be provided on the peripheral edge of the opening 302. In this case, the following configuration may be adopted: before the closing portion 41 contacts the sealing member 43 provided on the peripheral edge of the opening 302 on the hinge portion 5 side when the door 4 is rotated from the open state to the closed state, the closing portion 41 contacts the sealing member 43 on the side opposite to the hinge portion 5 side.

[0057] The door 4 is not limited to being rotatable about an axis L inclined in the front-rear direction relative to the vertical direction. For example, the door 4 may be rotatable about an axis extending horizontally at the upper or lower end of the door 4.

[0058] The closing portion 41 is not limited to a configuration in which the holding portion 42 can be separated from the holding portion 42 by elastically deforming the holding portion 42. For example, even if the closing portion 41 is connected to the holding portion 42 via another hinge portion (not shown) on the side opposite to the hinge portion 5, the closing portion 41 can be separated from the holding portion 42 on the hinge portion 5 side.

[0059] The closing portion 41 is not limited to a configuration in which it can rotate toward the housing 300 relative to the holding portion 42 due to its own weight. For example, a configuration in which the end portion of the closing portion 41 on the hinge portion 5 side can be separated from the holding portion 42 by a force other than gravity, such as by using the magnetic force generated by a magnet, and the end portion can be brought closer to the housing 300. Alternatively, the user can apply a force to the end portion of the closing portion 41 on the hinge portion 5 side in a direction toward the housing 300, thereby separating the end portion from the holding portion 42.

[0060] 5. Plan

[0061] Those skilled in the art will appreciate that the above-mentioned exemplary embodiments are specific examples of the following aspects.

[0062] (Item 1) A mass spectrometer according to one embodiment may include:

[0063] a housing having a vacuum chamber formed therein to be set to a vacuum state during analysis, and having an opening communicating with the vacuum chamber;

[0064] a door, for opening and closing the opening;

[0065] The hinge portion is configured to support the door so that it can rotate between an open state and a closed state.

[0066] The door includes a closing portion for closing the opening in a closed state, and a holding portion for holding the closing portion and connected to the hinge portion.

[0067] The closing portion is connected to the holding portion on the side opposite to the hinge portion and is configured to be detachable from the holding portion on the hinge portion side.

[0068] When the door is rotated from the open state to the closed state, the closing portion is configured to contact the peripheral edge of the opening on the side opposite to the hinge portion before the closing portion contacts the peripheral edge of the opening on the hinge portion side.

[0069] According to the mass spectrometer described in item 1, by rotating the door from an open state to a closed state, the sealing portion can be brought into contact with the peripheral edge of the opening on the side opposite the hinge portion. Subsequently, by separating the sealing portion from the retaining portion on the hinge portion side and bringing it closer to the opening, the sealing portion can be brought into close contact with the peripheral edge of the opening on the hinge portion side. Therefore, the opening communicating with the vacuum chamber can be sealed with a simpler operation.

[0070] (Item 2) It may be that in the mass spectrometer described in Item 1,

[0071] When the door is rotated from an open state to a closed state, the closing portion is configured to contact the peripheral edge of the opening on the opposite side of the hinge portion, and then the closing portion is tightly fitted with the peripheral edge of the opening on the hinge portion side by utilizing its own weight.

[0072] According to the mass spectrometer described in item 2, the sealing portion can be separated from the holding portion on the hinge side and brought closer to the opening by utilizing its own weight, so that the sealing portion automatically fits tightly against the peripheral edge of the opening on the hinge side. Therefore, the opening communicating with the vacuum chamber can be sealed with a simpler operation without providing additional components.

[0073] (Item 3) It may be that in the mass spectrometer described in Item 2,

[0074] The hinge portion is configured to support the door so as to be rotatable about an axis that is inclined in a direction toward the housing from an upper side.

[0075] According to the mass spectrometer described in item 3, the closing portion can be smoothly separated from the holding portion by its own weight about the axis and brought close to the opening, so that the closing portion automatically comes into close contact with the peripheral edge of the opening on the hinge side.

[0076] (Item 4) In the mass spectrometer described in any one of Items 1 to 3,

[0077] When the door is rotated from an open state to a closed state, the closing portion is configured to contact the peripheral edge of the opening on the opposite side of the hinge portion, and then the retaining portion is bent so that the closing portion is tightly fitted with the peripheral edge of the opening on the hinge portion side.

[0078] According to the mass spectrometer described in Item 4, the elastic deformation of the holding portion can be utilized to realize a configuration in which the closing portion can be separated from the holding portion on the hinge portion side.

[0079] (Item 5) In the mass spectrometer described in any one of Items 1 to 4,

[0080] The sealing portion includes a sealing member that contacts the peripheral edge of the opening in a closed state.

[0081] When the door is rotated from the open state to the closed state, the sealing member is configured to contact the peripheral edge of the opening on the side opposite to the hinge portion before contacting the peripheral edge of the opening on the hinge portion side.

[0082] According to the mass spectrometer described in item 5, by rotating the door from an open state to a closed state, the sealing member can be brought into contact with the peripheral edge of the opening on the side opposite the hinge portion. Subsequently, by separating the closing portion from the retaining portion on the hinge portion side and bringing it closer to the opening, the sealing member can be brought into close contact with the peripheral edge of the opening on the hinge portion side. Therefore, the opening communicating with the vacuum chamber can be sealed by the sealing member with a simpler operation.

[0083] (Item 6) In the mass spectrometer described in any one of Items 1 to 5,

[0084] A positioning mechanism is further provided for positioning the closing portion on the side opposite to the hinge portion when the door is rotated from the open state to the closed state.

[0085] According to the mass spectrometer described in item 6, when the door is rotated from the open state to the closed state, the sealing portion is always in a constant position relative to the opening and is in the closed state, so the vacuum chamber can be reliably sealed and the vacuum state can be achieved.

[0086] Description of Reference Numerals

[0087] 1. Mass analysis device

[0088] 4 doors

[0089] 5. Hinge

[0090] 6 Positioning mechanism

[0091] 30 Vacuum Chamber

[0092] 41 closed part

[0093] 42 Maintaining part

[0094] 43 Sealing parts

[0095] 300 housing

[0096] 302 Opening

[0097] L axis.

Claims

1. A mass analysis device, characterized in that have: a housing having a vacuum chamber formed therein to be set to a vacuum state during analysis, and having an opening communicating with the vacuum chamber; a door, openably and closably mounted on a portion of a wall of the housing that divides the vacuum chamber, for opening and closing the opening, wherein the opening is formed in the wall and is used for an operator to insert a hand or a tool into the housing; The hinge portion is configured to support the door so that it can rotate between an open state and a closed state. The door includes a closing portion for closing the opening in a closed state, and a holding portion for holding the closing portion and connected to the hinge portion. The closing portion is connected to the holding portion on the side opposite to the hinge portion and is configured to be detachable from the holding portion on the hinge portion side. When the door is rotated from the open state to the closed state, the closing portion is configured to contact the peripheral edge of the opening on the side opposite to the hinge portion before the closing portion contacts the peripheral edge of the opening on the hinge portion side. When the door is rotated from an open state to a closed state, the closing portion is configured to contact the peripheral edge of the opening on the opposite side of the hinge portion, and then the closing portion is tightly fitted with the peripheral edge of the opening on the hinge portion side by utilizing its own weight.

2. The mass spectrometer according to claim 1, wherein The hinge portion is configured to support the door so as to be rotatable about an axis that is inclined in a direction toward the housing from an upper side.

3. The mass spectrometer according to claim 1, wherein When the door is rotated from an open state to a closed state, the closing portion is configured to contact the peripheral edge of the opening on the opposite side of the hinge portion, and then the retaining portion is bent so that the closing portion is tightly fitted with the peripheral edge of the opening on the hinge portion side.

4. The mass spectrometer according to claim 1, wherein The sealing portion includes a sealing member that contacts the peripheral edge of the opening in a closed state. When the door is rotated from the open state to the closed state, the sealing member is configured to contact the peripheral edge of the opening on the side opposite to the hinge portion before contacting the peripheral edge of the opening on the hinge portion side.

5. The mass spectrometer according to claim 1, wherein Also features: The positioning mechanism positions the closing portion on the side opposite to the hinge portion when the door is rotated from the open state to the closed state.

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