CN114999886A - A kind of quadrupole mass analyzer assembly method and device - Google Patents

Abstract

The invention discloses an assembling method of a quadrupole rod mass analyzer, which belongs to the field of mass spectrometry and comprises the steps of device construction, electrode rod pre-placement, electrode rod position measurement and adjustment, ceramic ring installation, ceramic ring fixation, device disassembly and the like, wherein through the steps, the quadrupole field circle precision completely depends on the machining precision of a mandrel, and the size chain is reduced; the assembly process difficulty is reduced, and the position adjustment of the electrode rod in the process is simpler; the field diameter ratio of the quadrupole rods is controlled more accurately, the tolerance zone of the diameters of the electrode rod groups is widened, the process difficulty is reduced, and the yield is improved. The invention also relates to a quadrupole mass analyzer assembling device for implementing the quadrupole mass analyzer assembling method.

Description

A kind of quadrupole mass analyzer assembly method and device

technical field

The invention relates to the field of mass spectrometry, in particular to a method and device for assembling a quadrupole mass analyzer.

Background technique

The quadrupole mass analyzer is the core component of the quadrupole mass spectrometer, which is a device that uses the quadrupole field to screen the mass-to-charge ratio of certain ions. The mechanical structure of the quadrupole mass analyzer is extremely simple, generally consisting of only a ceramic support and four electrode rods. However, how to precisely assemble the four electrode rods on the ceramic holder and maintain dimensional stability is a huge problem. Its assembly accuracy directly determines the detection level of the mass spectrometer instrument.

In addition, a perfect quadrupole field needs to be generated by a high-precision hyperboloid electrode. However, due to the difficulty and cost of processing, most commercial quadrupole rods use cylindrical electrodes instead of hyperbolic electrodes to form quadrupole fields. The cylindrical electrode will generate high polar fields other than the quadrupole field, such as the dodecapole field and the twentipole field. These high polar field components will also affect the quality resolution of the quadrupole system. The research results show that when the radius r of the cylindrical electrode and the field radius r ₀ enclosed by it satisfy r/r ₀ =1.128～1.130, satisfactory ion transmission efficiency and mass resolution will be given, and the ratio is called Field diameter ratio. At present, most of the commercial quadrupole rods adopt the structure in which the cylindrical electrode rod is fixed by the ceramic ring through the screw. In this method, since the rod diameter of the pole has been determined, and the ceramic ring is bound to be difficult to ensure the inscribed circle size of the contact surface while ensuring the assembly accuracy, the inscribed circle error of the ceramic ring will eventually be The size error of the inscribed circle transmitted to the quadrupole affects the ion transmission efficiency and mass resolution. This method of researching ceramics requires continuous measurement and manual grinding, which requires a very high level of craftsmanship, which is one of the reasons for the low output and high price of the current quadrupole.

SUMMARY OF THE INVENTION

In order to overcome the deficiencies of the prior art, one of the objectives of the present invention is to provide a method for assembling a quadrupole mass analyzer which can precisely control the assembling position of the quadrupole and keep the field-diameter ratio within an ideal range.

In order to overcome the deficiencies of the prior art, the second purpose of the present invention is to provide a quadrupole mass analyzer assembly device that can precisely control the assembly position of the quadrupole and keep the field-diameter ratio within an ideal range.

One of the objects of the present invention adopts the following technical scheme to realize:

A method for assembling a quadrupole mass analyzer, comprising the following steps:

Device construction: four limit seats are fixed on the frame, an elastic limit structure is installed in each limit seat, the mandrel is fixed on the frame, and the four limit seats surround the mandrel and are opposite to the mandrel Symmetrical, and an adjustment piece is installed on each of the limit seats;

Electrode rod pre-placement: four electrode rods are evenly placed around the mandrel, and each electrode rod is in conflict with the elastic limit structure of the corresponding limit seat;

Electrode rod position measurement and adjustment: the position of each electrode rod is measured by the instrument, and the position of the electrode rod is adjusted by the adjusting member to make the position accuracy of the electrode rod meet the assembly requirements;

Install the ceramic ring: install the two ceramic rings on the two ends of the four electrode rods respectively, and the mandrel and the four electrode rods extend into the ceramic ring;

Fixing the ceramic ring: fix the ceramic ring with the four electrode rods;

Device disassembly: remove the four-limit seat along the quadrupole radial direction, and pull the ceramic ring and the four electrode rods off the mandrel.

Further, in the step of fixing the ceramic ring, the inner diameter of the ceramic ring is slightly larger than the circumscribed circle of the four electrode rods, and the gap between the electrode rod and the ceramic ring is filled with glue and fixed.

Further, in the step of fixing the ceramic ring, the fixing column is mounted on the ceramic ring and fixed with the electrode rod.

Further, in the electrode rod pre-placement step, the electrode rod collides with the pressure plate of the elastic limit structure, and the elastic member of the elastic limit structure applies elastic force to the pressure plate so that the position of the electrode rod can be adjusted.

Further, in the device building step, the number of elastic limiting structures in each limiting seat is two, and the elastic force directions of the two elastic limiting structures are vertical.

The second purpose of the present invention adopts the following technical scheme to realize:

A quadrupole mass analyzer assembly device, comprising a plurality of limit seats, a mandrel, a plurality of elastic limit structures and a plurality of adjustment parts, the plurality of the limit seats and the mandrel are fixed on a frame, A plurality of the limiting seats surround the mandrel and are symmetrical with respect to the mandrel. At least one elastic limiting structure is installed in each of the limiting seats. The elastic limiting structure includes an elastic member and a pressing plate. Two ends of the elastic piece are respectively in contact with the elastic piece and the pressing plate, the elastic piece provides elastic force to the pressing plate so that the pressing plate presses the electrode rod against the mandrel, and the adjusting piece is installed on the A limit seat, the adjusting member abuts against the electrode rod to adjust the position of the electrode rod.

Further, each of the limiting seats includes a first side plate, a second side plate and a third side plate, and the first side plate, the second side plate and the third side plate enclose an opening The opening faces the mandrel, and the electrode rod is partially located in the containing space and interferes with the mandrel.

Further, the first side plate is parallel to the third side plate, the two ends of the second side plate are respectively connected with the first side plate and the third side plate, and the second side plate is vertical Elastic limiting structures are respectively installed on the first side plate, the first side plate and the second side plate, and the pressing plates of the two elastic limiting structures are perpendicular to each other.

Further, the adjusting member is a screw, the screw is rotatably mounted on the third side plate and is in contact with the electrode rod, and the screw rotates relative to the third side plate to adjust the position of the electrode rod.

Further, the quadrupole mass analyzer assembly device further includes a resistance plate, the interference plate is installed on the end of the screw, and the screw interferes with the electrode rod through the interference plate.

Compared with the prior art, the assembling method of the quadrupole mass analyzer of the present invention has the following beneficial effects:

(1) The quadrupole mass analyzer assembly method makes the quadrupole field circle accuracy completely depend on the machining accuracy of the mandrel, reducing the dimension chain. In addition, the mandrel is shorter than the electrode rod, the material selection range is wide, the processing difficulty is low, and it is easy to achieve the sub-micron level.

(2) The difficulty of the assembly process is reduced, and the electrode rod position adjustment during the process becomes simpler. The traditional quadrupole needs to infer the grinding direction of the ceramic ring according to the distance data after measuring the distance between the rods, and the ceramic ring is manually repaired, the precision of the special-shaped surface is extremely difficult to control, and the process is difficult. However, in the assembly method proposed in this patent, since each electrode rod is closely attached to the outer surface of the mandrel, the freedom of movement is reduced, and the variable parameter is only the angle. The adjustment of a single parameter can be realized with only one adjustment screw, which is simple and precise.

(3) The control of the field diameter ratio of the quadrupole has become more precise, and the tolerance zone of the rod diameter of the electrode rod group is wider, which reduces the difficulty of the process and improves the yield. Because the traditional quadrupole needs to continuously measure the size and repair the ceramic ring until the assembly accuracy reaches the standard, it is easy to control the inner diameter of the ceramic in the process, which makes it difficult to control the circumscribed circle radius R of the quadrupole. The processing of the pole needs to ensure the cylindricity, and the rod diameter r is not easy to precisely control. The field circle radius r ₀ is coupled with their two parameters, r ₀ =R-2r, which makes the field-diameter ratio difficult to control. The method proposed in this patent can decouple the two parameters of the field circle radius, the rod diameter and the quadrupole circumscribed circle diameter, which is a fixed value and only depends on the diameter of the mandrel.

Description of drawings

Fig. 1 is a process schematic diagram of the quadrupole mass analyzer assembly method of the present invention;

Fig. 2 is the position adjustment schematic diagram of the quadrupole mass analyzer assembly method of Fig. 1;

3 is a schematic diagram of a bonding process of the assembling method of the quadrupole mass analyzer of FIG. 1;

FIG. 4 is a schematic diagram of another bonding process of the assembling method of the quadrupole mass analyzer of FIG. 1 .

In the figure: 10, limit seat; 11, first side plate; 12, second side plate; 13, third side plate; 20, elastic limit structure; 21, elastic piece; 22, pressure plate; 30, adjustment piece ; 40, the contact plate; 50, the mandrel; 200, the electrode rod; 300, the ceramic ring; 400, the fixed column.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be another intermediate component through which it is fixed. When a component is said to be "connected" to another component, it can be directly connected to the other component or there may be another intermediate component present at the same time. When a component is said to be "disposed on" another component, it may be directly disposed on the other component or there may be another intermediate component present at the same time. The terms "vertical," "horizontal," "left," "right," and similar expressions are used herein for illustrative purposes only.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

1 to 4 are schematic diagrams of an assembly method of a quadrupole mass analyzer, and the assembly method of the quadrupole mass analyzer includes:

A method for assembling a quadrupole mass analyzer, comprising the following steps:

Device construction: four limit seats 10 are fixed on the frame, an elastic limit structure 20 is installed in each limit seat 10, the mandrel 50 is fixed on the frame, and the four limit seats 10 surround the mandrel 50 and Symmetrical with respect to the mandrel 50 , an adjusting member 30 is installed on each of the limiting seats 10 ;

Pre-positioning of the electrode rods 200 : evenly placing the four electrode rods 200 around the mandrel 50 , each electrode rod 200 collides with the elastic limiting structure 20 of the corresponding limiting seat 10 ;

The position measurement and adjustment of the electrode rod 200: the position of each electrode rod 200 is measured by an instrument, and the position of the electrode rod 200 is adjusted by the adjusting member 30 so that the position accuracy of the electrode rod 200 can meet the assembly requirements;

Install the ceramic rings 300: install the two ceramic rings 300 on the two ends of the four electrode rods 200 respectively, and the mandrel 50 and the four electrode rods 200 extend into the ceramic rings 300;

The ceramic ring 300 is fixed: the ceramic ring 300 is fixed with the four electrode rods 200;

Disassembly of the device: the four limit seats 10 are removed in the radial direction, and the ceramic ring 300 and the four electrode rods 200 are pulled out from the mandrel 50 .

Specifically, in the step of fixing the ceramic ring 300 , the inner diameter of the ceramic ring 300 is slightly larger than the circumscribed circles of the four electrode rods 200 , and the gap between the electrode rods 200 and the ceramic ring 300 is filled with glue for fixing. The glue is epoxy glue. Another fixing method is: in the fixing step of the ceramic ring 300 , the fixing column 400 is installed on the ceramic ring 300 and fixed with the electrode rod 200 . In the pre-placement step of the electrode rod 200 , the electrode rod 200 collides with the pressing plate 22 of the elastic limiting structure 20 , and the elastic member 21 of the elastic limiting structure 20 applies elastic force to the pressing plate 22 so that the position of the electrode rod 200 can be adjusted. In the device building step, the number of the elastic limiting structures 20 in each limiting seat 10 is two, and the elastic force directions of the two elastic limiting structures 20 are vertical. The mandrel 50 is strictly cylindrical, and requires precise dimensional accuracy and shape accuracy. The size is designed according to the diameter of the electrode rod 200. Taking the commonly used rod diameters of 9.4mm and 12mm as an example, it is designed according to the field diameter ratio r/r ₀ =1.129 , the corresponding diameter of the mandrel 50 should be designed to be 8.326mm and 10.629mm. The applicable diameters of the electrode rods 200 are 9.392-9.408 and 11.990-12.010, and the machining tolerance zones of the two electrode rods 200 can be set to 16 μm and 20 μm. The assembling device takes 1/3-1/2 of the length of the electrode rods 200 , and the mandrel 50 can be fixed to the external frame through the gap between the four electrode rods 200 .

The present application also includes a quadrupole mass analyzer assembly device for implementing the above-mentioned quadrupole mass analyzer assembly method. The quadrupole mass analyzer assembly device includes a plurality of limit seats 10, a plurality of elastic limit structures 20, a plurality of adjustment 30 , several abutting plates 40 and a mandrel 50 .

The limit seat 10 is fixed to the frame. The number of the limit seats 10 is four, the mandrel 50 is located in the middle of the four limit seats 10 , and the four limit seats 10 are symmetrical about the mandrel 50 . Specifically, each limiting seat 10 includes a first side plate 11 , a second side plate 12 and a third side plate 13 . The first side plate 11 is parallel to the third side plate 13 . Both ends of the second side plate 12 are respectively connected to the first side plate 11 and the third side plate 13 , and the second side plate 12 is perpendicular to the first side plate 11 and the third side plate 13 . The first side plate 11 , the second side plate 12 and the third side plate 13 form a U-shaped structure. The limiting seat 10 is provided with an opening, and the opening faces the mandrel 50 . The four limit seats 10 are distributed in a cross shape.

Each elastic limiting structure 20 includes an elastic member 21 and a pressing plate 22 . The elastic member 21 is fixed on the inner wall of the limiting seat 10 , and the pressing plate 22 is fixed on the other end of the elastic member 21 . Specifically, the elastic member 21 is a spring. An elastic limiting structure 20 is installed on the first side plate 11 and the second side plate 12 of each limiting seat 10 . The elastic forces provided by the elastic members 21 of the two elastic limiting structures 20 are perpendicular to each other.

The number of the adjusting members 30 is the same as the number of the limiting seat 10 . Specifically, the number of adjustment members 30 is four. Each adjustment piece 30 is mounted on the third side plate 13 of the limiting seat 10 . Specifically, the adjusting member 30 is a screw, and the screw is rotatably mounted on the third side plate 13 , and the screw can adjust the distance that the end extends into the limit seat 10 by rotating the screw, that is, the position of the end of the screw, which is used to adjust the position of the electrode rod 200 . Location.

The abutting plate 40 is installed on the end of the adjusting member 30 , and the abutting plate 40 moves with the end of the adjusting member 30 and abuts the surface of the electrode rod 200 . The abutting plate 40 can adjust the position of the electrode rod 200 and prevent the electrode rod 200 from being damaged.

The mandrel 50 is fixed to the frame, and the four limit seats 10 are symmetrical about the mandrel 50 .

When using the quadrupole mass analyzer to assemble the device, the mandrel 50 is fixed to the external frame. First, the four electrode rods 200 are roughly evenly placed around the mandrel 50 . The elastic member 21 and the pressing plate 22 press the electrode rods 200 on the mandrel 50 continuously. , the position of the abutting plate 40 is controlled by the adjusting member 30, and the four limit seats 10 are fixed on the frame, so that the position of the four electrode rods 200 can be controlled by means of the four adjusting screws. Along the axis of the quadrupole, measure the position of each electrode rod 200 through a tool microscope or an image size measuring instrument, such as KEYENCE's LM series image size measuring instrument, the position measurement accuracy can reach 0.7μm, which meets the requirements of quadrupole assembly. On-line measurements can be used and corresponding adjustments can be made manually in real time according to the results until the electrode rod 200 is in the desired position, as shown in FIG. 2 . After the precise position adjustment of each electrode rod 200 is completed, the two ends of the quadrupole rod are sleeved with ceramic rings 300, which can be bonded in two ways. One is that the inner diameter of the ceramic ring 300 is slightly larger than the quadrupole circumscribed circle, such as As shown in FIG. 3 , epoxy glue is filled in the gap between the electrode rod 200 and the ceramic ring 300 . Alternatively, the electrode rod 200 can be screwed on the fixing post 400, the fixing post 400 passes through the through hole on the ceramic ring 300, and the gap between the ceramic ring 300 and the fixing post 400 is filled with epoxy glue, as shown in Figure 4 shown. Either way ceramic ring 300 does not require precise positioning.

Compared with applying for the quadrupole mass analyzer assembly method, it has the following beneficial effects:

(1) The quadrupole mass analyzer assembly method makes the quadrupole field circle accuracy completely depend on the machining accuracy of the mandrel 50, reducing the dimension chain. In addition, the mandrel 50 is shorter than the electrode rod 200, the material selection range is wide, the processing difficulty is low, and it is easy to achieve the sub-micron level.

(2) The difficulty of the assembly process is reduced, and the adjustment of the position of the electrode rod 200 during the process becomes simpler. The traditional quadrupole needs to infer the grinding direction of the ceramic ring 300 according to the distance data after measuring the distance between the rods, and the ceramic ring 300 is manually repaired, the precision of the special-shaped surface is extremely difficult to control, and the process is difficult. However, in the assembling method proposed in this patent, since each electrode rod 200 is closely attached to the outer surface of the mandrel 50, the degree of freedom of its movement is reduced, and the variable parameter is only the angle. The adjustment of a single parameter can be achieved with only one adjustment screw, which is simple and precise.

(3) The control of the field diameter ratio of the quadrupole rod becomes more precise, and the tolerance zone of the rod diameter of the electrode rod 200 is wider, which reduces the difficulty of the process and improves the yield. Because the traditional quadrupole needs to continuously measure the size and repair the ceramic ring 300 until the assembly accuracy reaches the standard, it is easy to make the inner diameter of the ceramic ring 300 difficult to control during the process, which makes the quadrupole circumscribed circle radius R difficult to control. The processing of the pole needs to ensure the cylindricity, and the rod diameter r is not easy to precisely control. The field circle radius r ₀ is coupled with their two parameters, r ₀ =R-2r, which makes the field-diameter ratio difficult to control. The method proposed in this patent can decouple the two parameters of the field circle radius, the rod diameter and the quadrupole circumscribed circle diameter, which is a fixed value and only depends on the diameter of the mandrel 50 .

For the convenience of comparison, the assembling method using circumscribed circle or circumscribed square to control the position of the electrode rod 200 is used as the control group (the method mentioned above is better than the current commercial quadrupole assembly method). Taking the commonly used 9.4mm rod diameter as an example, the diameter of the circumscribed circle should be designed as 2R=27.126mm, and when the actual processing rod diameter tolerance zone is e=10μm, the field circle radius is r ₀ =R-2r±e, which is 4.153- 4.173, the field diameter ratio r/r ₀ will be between 1.1257-1.1323, which is beyond the ideal range. Under the same rod diameter tolerance, the radius of the mandrel 50 designed by the patented method, that is, the field circle radius is r ₀ =4.163mm, and the field diameter ratio of the assembled quadrupole rod is between 1.1284-1.1296, which is within the ideal range. As mentioned above, if the method of this patent is adopted, the actual allowable rod diameter machining tolerance band corresponding to the field diameter ratio of 1.128-1.130 is 16 μm, which greatly broadens the optional range of the electrode rod 200 rod diameter and improves the electrode rod diameter. 200 processing yield, saving costs.

The above examples only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, which are all equivalent modifications to the above embodiments according to the essential technology of the present invention. and evolution, these all belong to the protection scope of the present invention.

Claims (10)

1. a quadrupole mass analyzer assembly method, is characterized in that, comprises the following steps: Device construction: four limit seats are fixed on the frame, an elastic limit structure is installed in each limit seat, the mandrel is fixed on the frame, and the four limit seats surround the mandrel and are opposite to the mandrel Symmetrical, and an adjustment piece is installed on each of the limit seats; Electrode rod pre-placement: four electrode rods are evenly placed around the mandrel, and each electrode rod is in conflict with the elastic limit structure of the corresponding limit seat; Electrode rod position measurement and adjustment: the position of each electrode rod is measured by the instrument, and the position of the electrode rod is adjusted by the adjusting member to make the position accuracy of the electrode rod meet the assembly requirements; Install the ceramic ring: install the two ceramic rings on the two ends of the four electrode rods respectively, and the mandrel and the four electrode rods extend into the ceramic ring; Fixing the ceramic ring: fix the ceramic ring with the four electrode rods; Device disassembly: remove the four limit seats along the radial direction of the four electrode rods, and pull out the ceramic ring and the four electrode rods from the mandrel. 2 . The method for assembling a quadrupole mass analyzer according to claim 1 , wherein in the ceramic ring fixing step, the inner diameter of the ceramic ring is slightly larger than the circumscribed circles of the four electrode rods. 3 . The gap between the electrode rod and the ceramic ring is filled with glue and fixed. 3 . The method for assembling a quadrupole mass analyzer according to claim 1 , wherein in the step of fixing the ceramic ring, a fixing column is installed on the ceramic ring and fixed with the electrode rod. 4 . 4 . The method for assembling a quadrupole mass analyzer according to claim 1 , wherein in the electrode rod pre-placement step, the electrode rod collides with the pressure plate of the elastic limit structure, and the elastic limit The elastic member of the structure applies elastic force to the pressing plate so that the position of the electrode rod can be adjusted. 5. The method for assembling a quadrupole mass analyzer according to claim 1, wherein in the device building step, the number of elastic limit structures in each limit seat is two, and two The elastic force direction of the elastic limiting structure is vertical. 6. A quadrupole mass analyzer assembly device, characterized in that it comprises a plurality of limit seats, a mandrel, a plurality of elastic limit structures and a plurality of adjustment parts, a plurality of the limit seats and the cores. The shaft is fixed on the frame, a plurality of the limiting seats surround the mandrel and are symmetrical with respect to the mandrel, each of the limiting seats is installed with at least one elastic limiting structure, and the elastic limiting structure includes elastic The two ends of the elastic piece are in contact with the elastic piece and the pressure plate respectively, the elastic piece provides elastic force to the pressure plate so that the pressure plate presses the electrode rod against the mandrel, the The adjusting piece is installed on the limiting seat, and the adjusting piece abuts against the electrode rod to adjust the position of the electrode rod. 7. The quadrupole mass analyzer assembly device according to claim 6, wherein each of the limiting seats comprises a first side plate, a second side plate and a third side plate, the first side plate The plate, the second side plate and the third side plate enclose a receiving space with an opening, the opening faces the mandrel, and the electrode rod is partially located in the receiving space and interferes with the mandrel. 8 . The quadrupole mass analyzer assembling device according to claim 7 , wherein the first side plate is parallel to the third side plate, and the two ends of the second side plate are respectively connected to the first side plate. 9 . One side plate and the third side plate are connected, the second side plate is perpendicular to the first side plate, the first side plate and the second side plate are respectively installed with elastic limiting structures, and the two The pressing plates of the elastic limiting structure are perpendicular to each other. 9 . The quadrupole mass analyzer assembling device according to claim 8 , wherein the adjusting member is a screw, and the screw is rotatably mounted on the third side plate and interferes with the electrode rod, and the screw Rotate relative to the third side plate to adjust the position of the electrode rod. 10 . The quadrupole mass analyzer assembly device according to claim 9 , wherein the quadrupole mass analyzer assembly device further comprises a resistance plate, and the abutment plate is installed on the end of the screw, and the 10 . The screw interferes with the electrode rod through the contact plate.

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