A collision cell structure and method of assembly thereof

Abstract

The application discloses a collision cell structure and an assembling method thereof, and belongs to the technical field of mass spectrometers. The collision cell comprises a shell, a front support, an electrode rod, a fixed seat, a connecting sleeve and an outlet lens. Double fixed seats are arranged in the shell in an axial direction. The electrode rod is bolted to the fixed seats at two ends. Limiting pins are arranged on the shell to be inserted into positioning holes to position the fixed seats. The connecting sleeve is matched with the front support through a circumferential limiting part. A double buckle structure of a clamping piece is used to realize quick locking. An unlocking piece can push the buckle to be released. In operation, ions enter from a central hole of the front support. The ions are focused or fragmented by colliding with collision gas under the action of a radio frequency electric field of the electrode rod. The ions are led out through the outlet lens. The double seat supporting structure is adopted to ensure parallelism of the electrode rod and assembling precision. The front support is quickly disassembled and assembled through the clamping piece, so that ion transmission efficiency and maintenance convenience are improved.

Description

Technical Field

[0001] This invention belongs to the field of mass spectrometry technology, specifically a collision cell structure and its assembly method. Background Technology

[0002] Collision cells are used in high-end analytical instruments such as inductively coupled plasma mass spectrometers (ICP-MS), triple quadrupole mass spectrometers (TQMS), and quadrupole-time-of-flight mass spectrometers (QFS), undertaking the dual critical tasks of ion collision focusing and collision-induced dissociation. The multipole system inside the collision cell applies a radio frequency electric field with specific parameters to effectively radially focus and confine the ion beam, trapping it in a potential well region near the central axis during its motion. Simultaneously, the collision gas filling the cell undergoes inelastic collisions with the ions entering the cell, dissipating kinetic energy to eliminate isotope interference or causing the parent ions to fragment for daughter ion analysis. In applications such as trace element analysis, ultra-trace metal speciation analysis, and detection of complex matrix samples, the performance of the collision cell directly determines the detection limit, dynamic range, and analytical precision of the entire mass spectrometer.

[0003] In collision cells, quadrupoles and octupoles are the two most common configurations. Quadrupoles, with their relatively simple structure and mature manufacturing process, were widely used in early collision cell designs. Their working principle is based on the superposition of radio frequency (RF) and DC electric fields, enabling stable ion transport within a specific mass number range under certain parameter conditions. Octupoles, by increasing the number of poles, achieve a more complex electric field distribution, maintaining relatively uniform ion transport efficiency over a larger mass number range, making them particularly suitable for analytical tasks requiring wide mass number scanning. However, regardless of the pole number configuration, the assembly accuracy of the poles is a key factor determining the final performance of the collision cell. The core objective of a multipole system is to construct a symmetrical and uniform multipole RF electric field in its axial central region, enabling ions entering the cell to achieve effective radial confinement and axial transport under the influence of this electric field. If there are parallelism or positional errors between the poles, the electric field distribution will deviate from the ideal state, causing electric field distortion in local areas between poles, forming a non-uniform potential well distribution, and thus reducing ion focusing and transport efficiency.

[0004] Existing collision pool structures present a contradiction between controlling the assembly precision of multi-pole rods and facilitating the disassembly and assembly of front-end components. Traditional collision pool structures typically employ a single-end-face fixation or direct internal positioning of the pole rods, lacking a support structure capable of providing independent, precise positioning references for both ends of the pole rods. During the locking process, the pole rods are highly susceptible to the combined effects of off-center load torque and accumulated component tolerances, resulting in microscopic tilting or warping deformation, making it difficult to effectively guarantee parallelism and coaxiality after assembly. Some existing technologies attempt to compensate for machining errors by adding adjusting shims or performing on-site fittings, but these methods are not only time-consuming, labor-intensive, and inefficient, but also highly dependent on the operator's experience and skill level for assembly precision, making it difficult to guarantee product consistency and repeatability, and hindering mass production. In addition, the front support, as a transitional component connecting the ion source and the collision cell, needs to be disassembled regularly for cleaning, maintenance, or replacement of the ion inlet components. Existing structures often use multiple screws to fix the front support to the cell body. During disassembly and assembly, special tools are needed to tighten all the screws one by one, which is cumbersome and time-consuming. Repeated disassembly and assembly can also easily lead to problems such as stripped screws and jamming, affecting the ease of instrument maintenance. Summary of the Invention

[0005] The purpose of this invention is to provide a collision pool structure and its assembly method to solve the following technical problems raised in the background art: Existing technologies cannot guarantee the assembly accuracy of a multipole system while also ensuring the ease of disassembly and assembly of front-end components.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: on the one hand: A collision pool includes a housing, a front support, poles, fixed seats, a connecting sleeve, and an exit lens. The housing has a mounting groove, within which two fixed seats are spaced apart along the axial direction. Each fixed seat has a plurality of bolt holes evenly spaced along the circumferential direction and also has positioning holes. Multiple poles are arranged evenly spaced along the circumferential direction within the fixed seats, with each pole's two ends connected to the fixed seats on either side by bolts. The housing has limit pins that insert into the positioning holes to achieve axial and circumferential positioning of the fixed seats. The connecting sleeve connects... On one side of the housing, circumferential limiting parts are provided on both sides of the connecting sleeve; the front bracket is provided on one side of the connecting sleeve, and the two sides of the front bracket respectively contact and cooperate with the circumferential limiting parts; a connecting groove is provided on the outer side of the connecting sleeve, and a snap-fit ​​component is provided in the connecting groove, with a first buckle and a second buckle respectively on both sides of the snap-fit ​​component; a first slot is provided on the front bracket, and a second slot is provided on the housing, with the first buckle snapping into the first slot and the second buckle snapping into the second slot; an unlocking component is also provided on the housing, which is used to push the second buckle out of the second slot; the exit lens is provided on the other side of the housing.

[0007] Furthermore, the pole is a hexapole or an octapole.

[0008] Furthermore, the exit lens is detachably connected to the housing via screws.

[0009] Furthermore, the latching component is an elastic component, and the unlocking component is a sliding unlocking lever. The bottom of the unlocking lever has a wedge-shaped structure, and one side of the bottom of the unlocking lever is slidably connected to the second slot.

[0010] Furthermore, a connecting seat is fixed to the outside of the housing, which is used to fix the collision cell to the vacuum chamber or support frame of the mass spectrometer.

[0011] Furthermore, a first limiting head and a second limiting head are fixedly connected to both sides of the connecting sleeve; a first limiting groove is provided on the front bracket, and a second limiting groove is provided on the housing; the first limiting head is engaged with the first limiting groove, and the second limiting head is engaged with the second limiting groove.

[0012] Furthermore, each pole has two mating holes, which are arranged along the axis of the pole and symmetrically with respect to the axis center.

[0013] Furthermore, a terminal block is detachably connected to the housing, and the terminal block passes through the housing and is electrically connected to the pole.

[0014] Furthermore, the circumferential limiting part is a protrusion provided on both sides of the connecting sleeve, and the inner side of the protrusion is a plane.

[0015] on the other hand: A method for assembling a collision pool, for assembling a collision pool as described in any of the preceding claims, includes the following steps: Step 1: Fix the housing on the assembly workbench, place the two fixing seats into the mounting slots respectively, so that the distance between the two fixing seats is equal to the length of the pole rod minus the screwing depth of the threads at both ends. Insert the limit pin into the positioning hole and press it into the corresponding hole of the housing to achieve dual positioning in the axial and circumferential directions. Use a dial indicator to measure the parallelism of the end faces of the two fixing seats. Step 2: Take multiple pole rods, pre-screw bolts into both ends of each pole rod, insert the pole rods between two fixed seats, so that the bolts pass through the bolt holes, and apply an initial preload torque to all bolts; Step 3: Set up a dual-frequency laser interferometer, take multiple cross-sections along the length of the poles, measure the center coordinates of each pole, and calculate the radial deviation and tilt angle of each pole. Step 4: Based on the measurement results, establish a finite element model to simulate the deformation behavior of each pole under different torques at both ends, obtain the bending stiffness coefficient of the pole, calculate the compensation torque required for each pole, and determine the final torque. Step 5: Tighten all bolts gradually in the preset grade sequence, pausing for a predetermined time after applying a predetermined torque at each grade. Step 6: After tightening all the poles, measure the parallelism of all poles again and make fine adjustments based on the measurement results; Step 7: Fix the connecting sleeve to the housing, install the snap-fit ​​parts, and snap the front bracket into the first and second slots through the first and second snap-fits to complete the locking, and then install the exit lens.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This collision cell structure of the present invention, through the axially spaced arrangement of two fixed seats within the housing and the positioning of limiting pins, combined with the bolt connection of each electrode rod to the fixed seat at both ends, forms a stable double-seat support structure. This effectively ensures the parallelism and overall assembly accuracy of multiple electrode rods after assembly, reduces the impact of assembly errors on electric field uniformity, and thus improves ion transport efficiency and analytical sensitivity. Simultaneously, the front support and housing are precisely circumferentially positioned via a circumferential limiting part on the connecting sleeve, and a double-buckle structure of the snap-fit ​​component enables quick locking. With the unlocking component, tool-free disassembly is possible, significantly simplifying the assembly and disassembly of the front support and improving the instrument's maintenance convenience and assembly efficiency.

[0017] This invention employs an assembly method combining laser interferometry and finite element analysis, achieving quantitative control and active compensation for pole assembly. This breaks through the traditional passive adjustment mode that relies on operator experience, significantly improving the consistency and repeatability of assembly accuracy. Through a graded, sequential tightening process design, stress concentration and pole deformation caused by improper bolt tightening sequence are effectively eliminated. Attached Figure Description

[0018] Figure 1 This is one of the overall structural schematic diagrams of the present invention; Figure 2 This is a cross-sectional schematic diagram of the present invention; Figure 3 This is the second schematic diagram of the overall structure of the present invention; Figure 4 This is the third schematic diagram of the overall structure of the present invention; Figure 5 This is a schematic diagram of the pole section of the present invention.

[0019] The markings in the diagram are: 1-Housing, 2-Connecting seat, 3-Exit lens, 4-Terminal post, 5-Front bracket, 6-Connecting sleeve, 7-Pole rod, 8-Fixing seat, 9-Limiting pin, 10-Circumferential limiting part, 11-First slot, 12-First buckle, 13-Snap-fit, 14-Connecting groove, 15-Second buckle, 16-Second slot, 17-Unlocking part, 18-First limiting groove, 19-First limiting head, 20-Second limiting head, 21-Second limiting groove, 22-Positioning hole, 23-Bolt hole. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Example 1:

[0021] A collision pool, such as Figure 1 as well as Figure 2 As shown, it includes a housing 1, a front bracket 5, an pole rod 7, a fixing base 8, a connecting sleeve 6, and an exit lens 3; as Figure 2 As shown, a mounting groove is provided inside the housing 1, and two fixing seats 8 are arranged at intervals along the axial direction within the mounting groove; as Figure 5 As shown, the fixing base 8 has several bolt holes 23 evenly spaced along the circumferential direction, and the fixing base 8 also has positioning holes 22; there are multiple pole rods 7, which are evenly spaced along the circumferential direction inside the fixing base 8, and the two ends of each pole rod 7 are connected to the fixing bases 8 on both sides by bolts; as shown Figure 2 As shown, a limiting pin 9 is provided on the housing 1. The limiting pin 9 is inserted into the positioning hole 22 to achieve axial and circumferential positioning of the fixed seat 8; the connecting sleeve 6 is connected to one side of the housing 1, and circumferential limiting parts 10 are provided on both sides of the connecting sleeve 6; the front bracket 5 is provided on one side of the connecting sleeve 6, and both sides of the front bracket 5 are in contact with the circumferential limiting parts 10 respectively; as shown Figure 3 as well as Figure 4 As shown, a connecting groove 14 is provided on the outer side of the connecting sleeve 6, and a snap-fit ​​component 13 is provided in the connecting groove 14. A first snap-fit ​​12 and a second snap-fit ​​15 are provided on both sides of the snap-fit ​​component 13, respectively. A first slot 11 is provided on the front bracket 5, and a second slot 16 is provided on the housing 1. The first snap-fit ​​12 is snapped into the first slot 11, and the second snap-fit ​​15 is snapped into the second slot 16. An unlocking component 17 is also provided on the housing 1. The unlocking component 17 is used to push the second snap-fit ​​15 out of the second slot 16. The exit lens 3 is provided on the other side of the housing 1.

[0022] The housing 1 serves as the main support structure of the collision pool, with an internal mounting groove to accommodate the mounting bases 8 and poles 7. Two mounting bases 8 are axially spaced within the mounting groove to support and position the poles 7 from both ends. Bolt holes 23 on the mounting bases 8 allow for bolt connection at the ends of the poles 7. Positioning holes 22 cooperate with limiting pins 9 to achieve precise axial and circumferential positioning of the mounting bases 8 within the housing 1. Multiple poles 7 are evenly arranged circumferentially and rigidly connected to the mounting bases 8 on both sides by bolts, forming a multi-pole system used to apply a radio frequency electric field to focus or fragment ions. Limiting pins 9 are inserted into the positioning holes 22 of the mounting bases 8 to ensure the relative positional accuracy of the two mounting bases 8, thereby guaranteeing the parallelism of the poles 7 after assembly. The sleeve 6 is fixed to one side of the housing 1, and the circumferential limiting parts 10 on both sides of the sleeve 6 contact and cooperate with the two sides of the front support 5 to achieve circumferential positioning of the front support 5 relative to the housing 1. The front support 5 is set on one side of the connecting sleeve 6 to support the ion inlet component and quickly connect to the housing 1. The snap-fit ​​component 13 is installed in the connecting groove 14 on the outside of the connecting sleeve 6, and its first snap 12 and second snap 15 are respectively snapped into the first slot 11 of the front support 5 and the second slot 16 of the housing 1 to achieve axial locking between the front support 5 and the housing 1. The unlocking component 17 is used to push the second snap 15 out of the second slot 16 so as to quickly disassemble the front support 5. The outlet lens 3 is set on the other side of the housing 1 to guide the ions after collision to the subsequent analyzer.

[0023] Specifically, during operation, ions enter the collision cell through the central channel of the front support 5. The radio frequency voltage applied to the multiple electrodes 7 generates a multi-electrode electric field, radially focusing and confining the ion beam. Simultaneously, collision gas, typically introduced through the gas path on the front support 5 or the housing 1, causes ions to collide, eliminating interfering ions or fragmenting the parent ions. The processed ions are then extracted through the exit lens 3 and enter the mass analyzer of the mass spectrometer. During assembly and maintenance, the connection between the front support 5 and the housing 1 is achieved using snap-fit ​​components 13: during installation, simply push the front support 5 to allow the first snap-fit ​​12 and the second snap-fit ​​15 to elastically engage with their corresponding slots, achieving quick locking without tools; when disassembly is required, operate the unlocking component 17 to push the second snap-fit ​​15 out of the second slot 16, simultaneously pulling out the front support 5, enabling tool-free quick disassembly and facilitating cleaning or component replacement inside the collision cell.

[0024] This collision cell structure, with two fixed seats 8 arranged axially at intervals and precisely positioned by limiting pins 9, combined with bolts connecting both ends of each pole 7 to the fixed seats 8, forms a stable double-seat support structure. This effectively ensures the parallelism and positional accuracy of the multiple poles 7 after assembly, reduces electric field distortion, and improves ion transmission efficiency and analytical sensitivity. On the other hand, the front support 5 and the housing 1 are quickly locked together by a double-clamp structure of the snap-fit ​​component 13, and tool-free disassembly and assembly are achieved with the unlocking component 17, greatly simplifying the assembly and disassembly of the front support 5 and improving the convenience of instrument maintenance and assembly efficiency.

[0025] In a preferred embodiment, the electrode 7 is a hexapole or an octapole. The hexapole can form a relatively uniform hexapole radio frequency electric field, reducing low-mass discrimination while ensuring ion focusing efficiency. Combined with a dual-support structure, it can fully utilize the transmission advantages of the hexapole field. The octapole provides a higher-order octapole electric field with stronger radial confinement capability, suitable for efficient ion capture under higher pressures, further reducing mass discrimination. The high-precision assembly of the eight electrodes can be ensured through staggered welding brackets and placement slots, meeting the electric field symmetry requirements of higher-resolution mass spectrometry.

[0026] In a preferred embodiment, the outlet lens 3 is detachably connected to the housing 1 by screws. This detachable connection facilitates individual disassembly, cleaning, or replacement of the outlet lens 3, adapting to different experimental requirements for outlet aperture or eliminating the problem of decreased ion transport efficiency due to contamination. It also simplifies maintenance operations and reduces repair costs.

[0027] In a preferred embodiment, the latching member 13 is an elastic element, and the unlocking member 17 is a sliding unlocking lever. The bottom of the unlocking lever has a wedge-shaped structure, and one side of the bottom of the unlocking lever is slidably connected to the second latch 16. The wedge-shaped inclined surface converts the linear movement of the lever into a smooth push on the second latch 15, causing the elastic latch to retract and disengage in a controllable manner. This avoids direct prying that could cause the latch to break or deform. At the same time, the sliding of the lever in the latch provides guidance and limitation, ensuring stable unlocking action and smooth feel, thereby improving the unlocking reliability and service life of the latching mechanism.

[0028] In a preferred embodiment, such as Figure 1 As shown, a connecting seat 2 is also fixed to the outside of the housing 1. The connecting seat 2 is used to fix the collision cell to the vacuum chamber or support frame of the mass spectrometer. The connecting seat 2 provides a standardized external installation interface for the entire collision cell, enabling it to be accurately and securely fixed to the vacuum chamber or support frame of the mass spectrometer and other analytical instruments. This ensures the positional stability of the collision cell during operation and facilitates the assembly, disassembly, and maintenance of the entire instrument.

[0029] In a preferred embodiment, such as Figure 4 As shown, a first limiting head 19 and a second limiting head 20 are fixedly connected to both sides of the connecting sleeve 6; a first limiting groove 18 is provided on the front bracket 5, and a second limiting groove 21 is provided on the housing 1; the first limiting head 19 is connected to the first limiting groove 18, and the second limiting head 20 is connected to the second limiting groove 21. Before the snap-fit ​​part 13 is locked, the front bracket 5 is precisely pre-positioned relative to the housing 1 and the connecting sleeve 6 and circumferentially anti-rotation is completed by the embedded cooperation of the limiting head and the limiting groove, so that it can be quickly and accurately embedded without repeated alignment during assembly. At the same time, the limiting structure can work with the circumferential limiting part 10 to bear the torsional torque after locking, avoiding the direct transmission of external force to the snap-fit, which may cause loosening or fatigue, and improving the assembly repeatability and connection reliability.

[0030] In a preferred embodiment, each pole 7 is provided with two mating holes, which are arranged along the axial direction of the pole 7 and symmetrically with respect to the axis of the pole 7. This design ensures that the preload applied by the two locking bolts is symmetrically and evenly distributed around the axis of the pole 7, eliminating the off-center load moment caused by unilateral force or asymmetrical locking, preventing micro-warping or tilting of the pole 7 ends, and ensuring that the pole 7 is fixed between the two fixing seats in a natural straight state, thereby guaranteeing the parallelism and overall assembly accuracy of the multi-pole poles 7 after assembly.

[0031] In a preferred embodiment, a terminal 4 is detachably connected to the housing 1, and the terminal 4 passes through the housing 1 and is electrically connected to the pole 7. The terminal 4 is used to reliably introduce external RF power or DC bias voltage into the internal pole 7, while facilitating the installation, replacement and maintenance of the terminal 4 and the wires.

[0032] In a preferred embodiment, the circumferential limiting part 10 is a protrusion provided on both sides of the connecting sleeve 6, and the inner side of the protrusion is a plane. By forming a surface contact fit with the side wall of the front bracket 5 through the plane, the contact area for circumferential positioning is increased, so that the front bracket 5 obtains a stable and uniform circumferential constraint force after assembly, preventing it from rotating around the axis, while facilitating processing and ensuring positioning accuracy.

[0033] on the other hand: A method for assembling a collision pool, for assembling a collision pool as described in any of the preceding claims, includes the following steps: Step 1: Fix the housing 1 on the assembly workbench, place the two fixing seats 8 into the mounting slots respectively, so that the distance between the two fixing seats 8 is equal to the length of the pole rod 7 minus the thread depth at both ends, insert the limiting pin 9 into the positioning hole 22 and press it into the corresponding hole of the housing 1 to achieve dual positioning in the axial and circumferential directions, and use a dial indicator to measure the parallelism of the end faces of the two fixing seats 8.

[0034] Step one aims to establish a precise reference for the fixed base 8, ensuring that the axial position and circumferential phase of the two fixed bases 8 within the housing 1 are accurately aligned, providing reliable positioning for the subsequent assembly of the pole rod 7. Specifically, the housing 1 is fixed on the assembly workbench, and the two fixed bases 8 are placed into their respective mounting slots. The distance between them is adjusted to equal the length of the pole rod 7 minus the thread depth at both ends. The limiting pin 9 is inserted into the positioning hole 22 and pressed into the corresponding hole in the housing 1 to achieve double positioning. Then, a dial indicator is used to measure the parallelism of the end faces of the two fixed bases 8, and compensation is made if necessary by adjusting the pin or the fixed base 8.

[0035] Step 2: Take multiple pole rods 7, pre-screw bolts into both ends of each pole rod 7, insert the pole rod 7 between the two fixing seats 8, so that the bolts pass through the bolt holes 23, and apply an initial pre-tightening torque to all bolts.

[0036] Step two serves to initially fix the pole rod 7 between the two fixed seats 8, placing it in a slightly movable state to provide conditions for subsequent measurement and calibration. Specifically, take multiple pole rods 7, pre-screw bolts into both ends of each, insert the pole rod 7 between the two fixed seats 8 so that the bolts pass through the bolt holes 23, and apply the same initial preload torque to all bolts. At this time, the pole rod 7 can move slightly axially but without radial wobble.

[0037] Step 3: Set up a dual-frequency laser interferometer, take multiple cross-sections along the length of pole 7, measure the center coordinates of each pole 7, and calculate the radial deviation and tilt angle of each pole 7.

[0038] Step three aims to accurately measure the spatial position deviation of each pole 7 relative to the reference axis, providing a data basis for subsequent tightening compensation. Specifically, a dual-frequency laser interferometer is set up, multiple cross-sections are taken along the length of the pole 7, the center coordinates of each pole 7 are measured, and the radial deviation and tilt angle of each pole 7 are calculated using the line connecting the center holes of the two fixing seats 8 as the reference axis, and the direction of deviation is recorded.

[0039] Step 4: Based on the measurement results, establish a finite element model to simulate the deformation behavior of each pole 7 under different torques at both ends, obtain the bending stiffness coefficient of the pole 7, calculate the compensation torque required for each pole 7, and determine the final torque.

[0040] Step four aims to calculate the final tightening torque required at both ends of each pole 7 based on the measured deviation, and to actively correct the positional deviation of the pole 7 using the elastic deformation generated during bolt tightening. Specifically, a finite element model is established to simulate the deformation behavior of each pole 7 under different torques at both ends. The bending stiffness coefficient of the pole 7 is obtained through experimental calibration, a target parallelism error is set, and the compensation torque required for each pole 7 is calculated. The final torque is the base torque plus the compensation torque, and the torque at both ends of each pole 7 can be set independently to compensate for the tilt angle.

[0041] Step 5: Tighten all bolts gradually according to the preset grade sequence, pausing for a predetermined time after applying a predetermined torque at each grade.

[0042] Step five aims to control the application of bolt preload through graded and sequential tightening, avoiding stress concentration and deformation of the pole rod 7 caused by a single tightening, while simultaneously releasing internal material stress. Specifically, all bolts are tightened progressively according to a preset graded sequence, for example, applying 40% of the final torque in the first stage, 70% in the second stage, and 100% in the third stage, with a predetermined pause between each stage. The tightening sequence follows a diagonal-to-adjacent method. After each stage, a portion of the pole rods 7 can be quickly sampled to confirm a normal trend.

[0043] Step 6: After tightening all the poles, measure the parallelism of all poles 7 again, and make fine adjustments based on the measurement results.

[0044] Step six is ​​to verify whether the parallelism after tightening meets the requirements and to perform local compensation correction for individual out-of-tolerance poles 7. Specifically, after tightening all poles, the parallelism of all poles 7 is measured again using a laser interferometer. If the out-of-tolerance of a certain pole 7 exceeds the set threshold, the two bolts at one end of that pole 7 are loosened by half a turn and then tightened again with the adjusted torque. This process is repeated no more than twice until all poles pass the test.

[0045] Step 7: Fix the connecting sleeve 6 to the housing 1, install the snap-fit ​​part 13, and snap the front bracket 5 into the first slot 11 and the second slot 16 through the first snap 12 and the second snap 15 to complete the locking, and install the exit lens 3.

[0046] Step seven completes the installation of the remaining components of the collision pool, enabling the rapid locking of the front bracket 5 and the fixation of the exit lens 3. Specifically, the connecting sleeve 6 is fixed to the side of the housing 1 near the front bracket 5, the snap-fit ​​13 is installed in the connecting groove 14 on the outside of the connecting sleeve 6, the front bracket 5 is pushed axially so that the first snap-fit ​​12 and the second snap-fit ​​15 elastically engage with the first slot 11 and the second slot 16 respectively to complete the locking, and finally the exit lens 3 is installed on the other side of the housing 1 with screws. Example 2:

[0047] The collision cell of this invention has an overall axially extending cylindrical structure, with its two ends pointing towards the ion inlet and ion outlet, respectively. Specifically, the total length of the collision cell is approximately 150mm to 200mm, and the outer diameter is approximately 60mm to 80mm. This size design fully considers the space constraints of the vacuum chamber of the mass spectrometer and the requirements for ion optical transmission efficiency. The housing 1 is made of high-strength stainless steel or aluminum alloy, and its wall thickness is set between 3mm and 5mm according to the mechanical strength requirements and vacuum sealing requirements. The interior of the housing 1 is a cavity structure, which is used to accommodate the electrode assembly, the collision gas channel, and the ion optical elements. Flange structures for connecting the front support 5 and the outlet lens 3 are respectively provided at both ends of the housing 1, and corresponding screw holes and sealing grooves are machined on the flange surface.

[0048] A mounting groove is provided on the side wall of the housing 1, which is opened along the axial direction of the housing 1 to form a continuous groove structure. The depth of the mounting groove is approximately 8mm to 12mm, and the width is approximately 15mm to 20mm, with the specific dimensions determined according to the external dimensions of the fixing seat 8 and the installation requirements. In a preferred embodiment, the cross-sectional shape of the mounting groove is rectangular, which can provide stable support and accurate positioning for the fixing seat 8. Two fixing seats 8 are arranged at intervals along the axial direction within the mounting groove. The distance between the two fixing seats 8 can be adjusted within a certain range according to the length of the pole 7 and the assembly requirements, typically set between 120mm and 160mm. The two fixing seats 8 are located near the two ends of the mounting groove, and their axial positions determine the effective working length of the pole 7.

[0049] The mounting base 8 is made of high-strength insulating material, such as polyetheretherketone (PEEK) or alumina ceramic, which possesses excellent mechanical strength, good insulation properties, and stable thermal expansion characteristics. The mounting base 8 is generally annular or a plate structure with a central hole through which the pole rod 7 passes. Several bolt holes 23 are evenly spaced along the circumferential direction on the mounting base 8, the number of which matches the number of pole rods 7. In a six-pole embodiment, the mounting base 8 has six bolt holes 23, evenly distributed circumferentially, with an angular interval of 60° between adjacent bolt holes 23. The diameter of the bolt holes 23 is slightly larger than the outer diameter of the bolt, typically set to 1.1 to 1.2 times the outer diameter of the bolt, to ensure smooth screw insertion and provide sufficient locking force. Each mounting base 8 also has a positioning hole 22, which cooperates with the limiting pin 9 to precisely determine the position of the mounting base 8 within the mounting groove. In a preferred embodiment, the positioning hole 22 is a round hole with a diameter of 3mm to 5mm, and the corresponding limiting pin 9 is a cylindrical pin with a corresponding diameter.

[0050] The poles 7 are the core ion optical elements of the collision cell, and their number and arrangement directly affect the ion transport efficiency and focusing effect within the collision cell. In a specific embodiment of the present invention, the poles 7 adopt a hexapole structure, that is, six poles 7 are evenly spaced circumferentially. The axes of the six poles 7 are parallel to the central axis of the collision cell, and they are distributed at equal angles around the central axis, with an angular interval of 60° between adjacent poles 7. The length of each pole 7 is approximately between 140mm and 190mm, and the diameter is approximately between 6mm and 10mm. Each end of the pole 7 is provided with a threaded section for bolt connection with the fixing seat 8, the length of which is approximately 8mm to 15mm, and the thread specification is M3 to M4. Two mating holes are machined on the cylindrical surface of the pole 7. These two mating holes are arranged along the axial direction of the pole 7 and are symmetrically arranged with respect to the axis of the pole 7. As a preferred embodiment of the present invention, these two mating holes are centrally symmetrically arranged on the pole 7, that is, the two holes are located at the same distance on both sides of the axis of the pole 7. This symmetrical arrangement ensures that the preload applied by the two locking bolts is symmetrically and evenly distributed around the axis of pole rod 7, eliminating the off-center load moment caused by unilateral force or asymmetrical locking. This effectively prevents micro-warping or tilting of the pole rod 7 end during tightening, ensuring that each pole rod 7 can be fixed between the two fixing seats 8 in a natural and straight state.

[0051] A limiting pin 9 is provided on the housing 1. The limiting pin 9 is a cylindrical structure made of high-hardness stainless steel or tungsten carbide. The diameter of the limiting pin 9 is slightly smaller than the inner diameter of the positioning hole 22, and it is usually connected to the positioning hole 22 by an interference fit or a clearance fit. During assembly, the limiting pin 9 is inserted into the positioning hole 22 to achieve axial and circumferential positioning constraints on the fixed seat 8. There are at least two limiting pins 9, which mate with the positioning holes 22 on two fixed seats 8 respectively. In a specific embodiment, each fixed seat 8 is provided with two positioning holes 22, and correspondingly, two limiting pins 9 are provided on the housing 1. These two limiting pins 9 are symmetrically arranged with respect to the central hole of the fixed seat 8.

[0052] The connecting sleeve 6 is connected to one side of the housing 1, and its function is to enable quick assembly and disassembly and precise circumferential positioning between the front bracket 5 and the housing 1. The overall shape of the connecting sleeve 6 is a cylindrical or annular structure, with its inner diameter slightly larger than the outer diameter of the housing 1, so that it can be fitted onto the outside of the housing 1. Circumferential limiting portions 10 are provided on both sides of the connecting sleeve 6, and these circumferential limiting portions 10 are protrusions provided on both sides of the connecting sleeve 6. In a preferred embodiment, the circumferential limiting portions 10 are protrusions provided on both sides of the connecting sleeve 6, and the inner side of the protrusions is a plane. This plane forms a surface contact fit with the side wall of the front bracket 5, increasing the contact area for circumferential positioning, so that the front bracket 5 can obtain a more stable and uniform circumferential constraint force when embedded and assembled. A connecting groove 14 is provided on the outer side of the connecting sleeve 6, which extends along the circumferential direction of the connecting sleeve 6, and its width and depth are determined according to the size of the snap-fit ​​member 13. The snap-fit ​​member 13 is provided in the connecting groove 14, and the snap-fit ​​member 13 is an elastic element, such as a spring steel sheet or an elastic plastic element. The overall shape of the snap-fit ​​component 13 is sheet-like or block-like, with a first snap-fit ​​12 and a second snap-fit ​​15 on each side. The first snap-fit ​​12 and the second snap-fit ​​15 are protruding snap-fit ​​tongue structures on the snap-fit ​​component 13, and their shape and size match the corresponding snap-fit ​​grooves.

[0053] The front bracket 5 is located on one side of the connecting sleeve 6. Its function is to support the electrode structure at the ion inlet end and provide a channel for ions to enter the collision cell. A central hole with a diameter of approximately 4mm to 8mm is provided in the center of the front bracket 5, through which ions enter the collision cell. The front bracket 5 has a first slot 11, the shape and size of which match the first buckle 12, allowing the first buckle 12 to be engaged and fixed within the first slot 11. The housing 1 has a second slot 16, the shape and size of which match the second buckle 15, allowing the second buckle 15 to be engaged and fixed within the second slot 16. The first buckle 12 of the latching member 13 engages in the first slot 11, while the second buckle 15 engages in the second slot 16. This double-buckle structure enables quick locking between the front bracket 5 and the housing 1.

[0054] The housing 1 is also equipped with an unlocking component 17, which is used to push the second latch 15 out of the second slot 16, thereby enabling the quick disassembly of the front bracket 5. In a specific embodiment, the unlocking component 17 is a sliding unlocking lever with a wedge-shaped bottom. One side of the bottom of the unlocking lever is slidably connected to the second slot 16. By pushing and pulling the unlocking lever, the wedge-shaped slope at its bottom gradually intervenes and forces the second latch 15, which acts as an elastic element, to elastically retract, thereby converting the operating force applied to the lever into a stable and controllable disengagement action through the wedge. This design avoids brittle fracture or plastic deformation caused by directly prying the latch, while the bottom of the lever always slides within the second slot 16, providing full guidance and limitation for the unlocking action, ensuring smooth operation and accurate reset.

[0055] An exit lens 3 is located on the other side of the housing 1, and its function is to extract ions from the collision cell after they have been focused or fragmented. The exit lens 3 is a disc-shaped electrode structure with an ion extraction hole at its center. In one specific embodiment, the exit lens 3 is detachably connected to the housing 1 by screws. This design facilitates the individual disassembly, cleaning, or replacement of the exit lens 3 to meet the different experimental requirements for the exit hole diameter or to eliminate the problem of decreased ion transport efficiency due to contamination. The diameter of the ion extraction hole on the exit lens 3 can be selected according to experimental requirements, typically set between 2 mm and 6 mm.

[0056] A terminal 4 is detachably connected to the housing 1, passing through the housing 1 and electrically connected to the internal electrode 7. The terminal 4 reliably introduces external RF power or DC bias voltage into the internal electrode 7 via the wall of the housing 1. The detachable connection facilitates the installation, replacement, and maintenance of the terminal 4 and its connected wires. In a preferred embodiment, the terminal 4 is fixed to the housing 1 by a threaded connection, and a sealing gasket is provided at the connection point to the housing 1 to ensure vacuum sealing performance.

[0057] A connecting seat 2 is also fixedly attached to the outside of the housing 1, providing a standardized external mounting interface for the entire collision cell. The connecting seat 2 has standardized mounting holes and positioning structures, allowing it to be precisely and securely fixed to the vacuum chamber or support frame of analytical instruments such as mass spectrometers. In one specific embodiment, the connecting seat 2 adopts a flange structure with four evenly distributed mounting screw holes, the angular interval between adjacent screw holes being 90°.

[0058] In another preferred embodiment of the present invention, a first limiting head 19 and a second limiting head 20 are fixedly connected to both sides of the connecting sleeve 6. A first limiting groove 18 is provided on the front bracket 5, and a second limiting groove 21 is provided on the housing 1. The first limiting head 19 is engaged with the first limiting groove 18, and the second limiting head 20 is engaged with the second limiting groove 21. Before the front bracket 5 and the housing 1 are axially locked by the snap-fit ​​member 13, the embedded engagement of the limiting head and the limiting groove is used to complete the precise pre-positioning and circumferential anti-rotation constraint of the front bracket 5 relative to the housing 1 and the connecting sleeve 6, so that the front bracket 5 can be quickly and accurately embedded into the correct position without repeated manual alignment during the assembly process. At the same time, this limiting structure can also work with the circumferential limiting part 10 to bear the torsional torque that the front bracket 5 may be subjected to after the snap-fit ​​member 13 is locked, avoiding the direct transmission of external force to the snap-fit ​​point, which may lead to accidental loosening or fatigue of the snap-fit ​​member 13.

[0059] The working process of the collision cell of this invention is as follows: Ions enter the collision cell through the central hole of the front support 5 and collide with the collision gas under the action of the radio frequency electric field applied by the electrode 7, achieving focusing or fragmentation. The collision gas enters the collision cell through a dedicated gas inlet, and its flow rate is precisely regulated by a mass flow controller. The electrode 7 is connected to an external radio frequency power supply through the terminal 4. The radio frequency power supply provides the electrode 7 with a high-frequency AC voltage, typically with a frequency of several hundred kilohertz to several megahertz and a voltage amplitude of several hundred volts to several thousand volts. Under the action of the radio frequency electric field, the ions move in the electric field potential trap formed by the electrode 7 and collide with the collision gas molecules, achieving energy reduction and focusing or fragmentation. Finally, the processed ions are led out of the collision cell through the exit lens 3 and enter the subsequent mass analyzer.

[0060] The collision cell of this invention utilizes the axially spaced arrangement of two fixed seats 8 within the housing 1 and the positioning of limiting pins 9, combined with the bolt connection of each electrode rod 7 to its two ends to the fixed seats 8, forming a stable double-seat support structure. This double-seat support structure effectively ensures the parallelism and overall assembly accuracy of the multiple electrode rods 7 after assembly, reducing the impact of assembly errors on the uniformity of the electric field, thereby improving ion transport efficiency and analytical sensitivity. Simultaneously, the front support 5 and the housing 1 are precisely circumferentially positioned via the circumferential limiting part 10 on the connecting sleeve 6, and quickly locked using the double-buckle structure of the snap-fit ​​part 13. With the unlocking part 17, tool-free disassembly is possible, significantly simplifying the assembly and disassembly of the front support 5 and improving the instrument's maintenance convenience and assembly efficiency. The overall structure is compact, and the positioning of each functional component is reliable, balancing the needs of high-precision assembly and convenient disassembly.

[0061] The assembly method of the collision pool of the present invention is described in detail below. This assembly method is applicable to collision pools with a six-pole structure, and achieves quantitative control and active compensation of the pole assembly by combining laser interferometry and finite element analysis.

[0062] Step 1: Establishing the reference for the fixed base. Fix the housing 1 to the assembly workbench, ensuring that the axis of the housing 1 is horizontal and perpendicular to the reference plane of the workbench. Place the two fixed bases 8 into the mounting slots, making the distance between them equal to the length of the pole rod 7 minus the thread depth at both ends. In a specific embodiment, the total length of the pole rod 7 is 160mm, and the thread depth at both ends is 10mm, so the distance between the two fixed bases 8 is set to 140mm. Insert the limiting pin 9 into the positioning hole 22 of the fixed base 8 and press it into the corresponding hole in the housing 1 to achieve dual positioning in the axial and circumferential directions. Use a dial indicator to measure the parallelism of the end faces of the two fixed bases 8. If the deviation is greater than 0.005mm, grind the end face of the limiting pin 9 or replace the pin until the requirements are met. This step ensures the positional accuracy of the two fixed bases 8 within the housing 1, providing a stable reference for the subsequent assembly of the pole rod 7.

[0063] Step 2, Initial Pre-tightening of the Pole Rods. Take six pole rods 7, and pre-screw bolts into both ends of each pole rod 7. Insert the pole rods 7 between the two fixing seats 8, so that the bolts pass through the bolt holes 23. Apply an initial torque of 0.2 N·m to all bolts. At this time, the pole rods 7 can move slightly axially within the fixing seats 8, but there is no radial clearance. The design of the initial pre-tightening torque ensures that the pole rods 7 remain stable during subsequent measurements and adjustments, while preventing irreversible deformation of the pole rods 7 due to excessive pre-tightening force.

[0064] Step 3, Laser Interferometry. Set up a dual-frequency laser interferometer and take five cross-sections along the length of pole 7, measuring the center coordinates of each pole 7. The five cross-sections are located at 10%, 30%, 50%, 70%, and 90% of the distance from one end of pole 7, respectively. Using the line connecting the center holes of the two mounting bases 8 as the reference axis, calculate the radial deviation and tilt angle of each pole 7. The radial deviation is defined as the offset of the pole 7 axis relative to the reference axis, and the tilt angle is defined as the angle between the pole 7 axis and the reference axis. Record the direction of the deviation, including its angular position in the radial plane.

[0065] Step 4: Tightening Torque Calculation. A finite element model is established to simulate the deformation behavior of each pole 7 under different torques at both ends. The bending stiffness coefficient of the pole 7 is obtained through experimental calibration. In a specific embodiment, the bending stiffness coefficient is approximately 0.01 μm of bending deformation per (N·m) (i.e., the stiffness coefficient is 0.01 μm / (N·m)). Setting the target parallelism error to 0.5 μm, the compensation torque required for each pole 7 is equal to the difference between the measured deviation and the target value divided by the stiffness coefficient. The reference torque is taken as 1.2 N·m. The final torque is equal to the reference torque plus the compensation torque. The torques at both ends of each pole 7 can be set independently to compensate for the tilt angle.

[0066] Step 5: Tighten in stages. The following sequence is used: First stage: Apply 0.5 N·m to all bolts circumferentially, pause for 60 seconds. Second stage: Apply 0.9 N·m to all bolts diagonally, pause for 60 seconds. Third stage: Apply the calculated final torque diagonally. After each stage, quickly sample three pole rods 7 using a laser interferometer to confirm no obvious abnormal trends. This staged tightening process effectively eliminates stress concentration and pole rod 7 deformation caused by improper bolt tightening sequence, ensuring the reliable achievement of the final parallelism target.

[0067] Step Six: Retest and Fine-tuning. After tightening all the bolts, measure the parallelism of all poles 7 again. If the deviation of any pole 7 exceeds 1μm, loosen the two bolts at one end by half a turn and tighten them again with the adjusted torque. Repeat this step no more than twice to ensure that the parallelism of all poles 7 does not exceed 1μm / 100mm.

[0068] Step 7: Install the remaining components. Fix the connecting sleeve 6 to the housing 1, install the snap-fit ​​component 13, and snap the front bracket 5 into the first slot 11 and the second slot 16 via the first snap 12 and the second snap 15 to complete the locking. The exit lens 3 is fixed with screws.

[0069] As another embodiment of the assembly method of the present invention, when the collision pool adopts an octagonal bar assembly, the assembly method includes the following steps.

[0070] Step 1: Pre-treatment of the welding supports. Coordinate measurements are performed on both sides of the welding supports, recording the deviation of the actual position of each placement slot from its theoretical position. For placement slots with deviations exceeding the standard, compensation is achieved through minor grinding or the use of shims.

[0071] Step 2, Pole Pre-positioning and Measurement. Place the four poles 7 into the placement slots of one side of the welding bracket, without welding, relying solely on gravity for positioning. Use a laser displacement sensor to measure the axial height and horizontal offset of each pole 7. Based on the measurement results, insert metal foils of varying thicknesses into the bottom of the placement slots to bring the four poles 7 to their theoretical positions. Repeat the same process on the other side of the welding bracket.

[0072] Step 3, Welding and Stress Relief. The adjusted pole 7 is spot-welded to the welding bracket, with two spots welded on each pole 7. Immediately after welding, high-frequency vibration is used to relieve welding stress: vibration frequency 200Hz, amplitude 0.1mm, duration 30s. Then, full welding is performed.

[0073] Step 4: Assemble the two side supports. Connect the two side welded supports using the intermediate support and screws. During connection, pre-tighten the screws to 0.5 N·m, and measure the circumferential division of the eight pole rods 7. If the deviation exceeds 0.05°, compensate by slightly torturing the welded support by adjusting the pre-tightening force of the fine-tuning screws. Finally, tighten the screws to 1.0 N·m.

[0074] Step 5: Install the assembly into the housing. Install the assembled octagonal rod assembly into housing 1, and bolt both ends to the fixing base 8.

[0075] The octupole structure of this invention has advantages in applications requiring higher ion capacity and lower mass discrimination. The octupole can form a more uniform multi-pole radio frequency electric field within the ion transport region, resulting in a smoother potential well distribution of ions near the central axis, effectively balancing ion focusing performance with transport efficiency over a wide mass number range.

[0076] In the above specific embodiments, the material selection and dimensional parameters of each component can be adjusted according to actual application requirements. For example, the housing 1 can be made of stainless steel to provide better mechanical strength and corrosion resistance, or it can be made of aluminum alloy to reduce overall weight. The mounting base 8 can be made of polyetheretherketone (PEEK) to provide good insulation, or it can be made of alumina ceramic to provide higher mechanical strength and high-temperature resistance. The pole 7 can be made of stainless steel or have a gold-plated surface treatment to provide better conductivity and corrosion resistance.

[0077] The collision cell structure and assembly method of the present invention ensure the assembly accuracy of the pole 7 through the double fixed seat 8 support structure, realize the quick disassembly and assembly of the front bracket 5 through the snap-fit ​​part 13 and the unlocking part 17, and realize the quantitative control of the assembly of the pole 7 through laser interferometry and finite element analysis. The overall design takes into account the needs of high-precision assembly and convenient disassembly and assembly, and is suitable for ion collision focusing applications of various mass spectrometers.

[0078] In the description of this invention, it should be understood that the terms "coaxial," "bottom," "one end," "top," "middle," "other end," "upper," "side," "top," "inner," "front," "center," "both ends," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0079] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0080] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A collision pool, characterized in that: Includes housing (1), front bracket (5), pole rod (7), mounting base (8), connecting sleeve (6), and exit lens (3); The housing (1) is provided with an installation groove, and two fixing seats (8) are provided at intervals along the axial direction in the installation groove; a number of bolt holes (23) are provided evenly at intervals along the circumferential direction on the fixing seats (8), and positioning holes (22) are also provided on the fixing seats (8). There are multiple pole rods (7), which are evenly spaced along the circumferential direction in the fixed seat (8). The two ends of each pole rod (7) are connected to the fixed seats (8) on both sides by bolts. A limiting pin (9) is provided on the housing (1). The limiting pin (9) is inserted into the positioning hole (22) and realizes the axial and circumferential positioning of the fixed seat (8). The connecting sleeve (6) is connected to one side of the housing (1), and circumferential limiting parts (10) are provided on both sides of the connecting sleeve (6); the front bracket (5) is provided on one side of the connecting sleeve (6), and the two sides of the front bracket (5) respectively contact and cooperate with the circumferential limiting parts (10); A connecting groove (14) is provided on the outer side of the connecting sleeve (6), and a snap fastener (13) is provided in the connecting groove (14). A first snap fastener (12) and a second snap fastener (15) are provided on both sides of the snap fastener (13). The front bracket (5) is provided with a first slot (11), and the housing (1) is provided with a second slot (16). The first buckle (12) is engaged in the first slot (11), and the second buckle (15) is engaged in the second slot (16). The housing (1) is also provided with an unlocking component (17), which is used to push the second latch (15) out of the second slot (16); the exit lens (3) is provided on the other side of the housing (1).

2. The collision pool according to claim 1, characterized in that: The pole (7) is a six-pole or an eight-pole pole.

3. A collision pool according to claim 1, characterized in that: The exit lens (3) is detachably connected to the housing (1) by screws.

4. A collision pool according to claim 1, characterized in that: The snap-fit ​​part (13) is an elastic part, and the unlocking part (17) is a sliding unlocking lever. The bottom of the unlocking lever has a wedge-shaped structure, and one side of the bottom of the unlocking lever is slidably connected to the second slot (16).

5. A collision pool according to claim 1, characterized in that: A connecting seat (2) is also fixed to the outside of the housing (1). The connecting seat (2) is used to fix the collision cell to the vacuum chamber or support frame of the mass spectrometer.

6. A collision pool according to claim 1, characterized in that: The connecting sleeve (6) is also fixedly connected to the first limiting head (19) and the second limiting head (20) on both sides; the front bracket (5) is provided with the first limiting groove (18), and the housing (1) is provided with the second limiting groove (21); the first limiting head (19) is connected to the first limiting groove (18), and the second limiting head (20) is connected to the second limiting groove (21).

7. A collision pool according to claim 1, characterized in that: Each pole (7) is provided with two mating holes. The two mating holes are arranged along the axial direction of the pole (7) and are symmetrically arranged with respect to the axial center of the pole (7).

8. A collision pool according to claim 1, characterized in that: A terminal (4) is detachably connected to the housing (1), and the terminal (4) passes through the housing (1) and is electrically connected to the pole (7).

9. A collision pool according to claim 1, characterized in that: The circumferential limiting part (10) is a protrusion provided on both sides of the connecting sleeve (6), and the inner side of the protrusion is a plane.

10. A method for assembling a collision pool, used to assemble a collision pool according to any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Fix the housing (1) on the assembly workbench, place the two fixed seats (8) into the mounting slots respectively, so that the distance between the two fixed seats (8) is equal to the length of the pole rod (7) minus the thread depth at both ends, insert the limiting pin (9) into the positioning hole (22) and press it into the corresponding hole of the housing (1) to achieve dual positioning in the axial and circumferential directions, and use a dial indicator to measure the parallelism of the end faces of the two fixed seats (8); Step 2: Take multiple pole rods (7), screw bolts into both ends of each pole rod (7), insert the pole rod (7) between two fixed seats (8), so that the bolts pass through the bolt holes (23), and apply an initial preload torque to all bolts; Step 3: Set up a dual-frequency laser interferometer, take multiple cross sections along the length of the pole rod (7), measure the center coordinates of each pole rod (7), and calculate the radial deviation and tilt angle of each pole rod (7); Step 4: Based on the measurement results, establish a finite element model to simulate the deformation behavior of each pole (7) under different torques at both ends, obtain the bending stiffness coefficient of the pole (7), calculate the compensation torque required for each pole (7), and determine the final torque; Step 5: Tighten all bolts gradually in the preset grade sequence, pausing for a predetermined time after applying a predetermined torque at each grade. Step 6: After tightening all the poles, measure the parallelism of all poles (7) again and make fine adjustments based on the measurement results; Step 7: Fix the connecting sleeve (6) to the housing (1), install the snap fastener (13), and snap the front bracket (5) into the first slot (11) and the second slot (16) through the first snap fastener (12) and the second snap fastener (15) to complete the locking, and install the exit lens (3).

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