X-ray source filament mounting structure and method

Abstract

The application provides an X-ray source filament mounting structure, comprising: a device main body, an axial limiting portion being arranged on the device main body; a filament seat, the filament seat being connected to the device main body, and a lower end surface of the filament seat abutting against the axial limiting portion, an installation space being formed between the filament seat and the device main body; a filament main body, located in the installation space; an elastic pre-tightening piece, arranged in the device main body, a top end of the elastic pre-tightening piece abutting against a lower end surface of the filament main body, for applying an axial elastic force to the filament main body, so that the filament main body abuts against the filament seat; and a locking piece, for relatively fixing the filament main body and the filament seat. The application ensures that the installation position of the filament seat is consistent each time through the axial limiting portion, realizes calibration-free replacement of the filament, the elastic pre-tightening piece eliminates the axial fitting gap and guarantees long-term stability, and the locking piece prevents the filament main body from moving, so that high-precision and rapid installation is realized through the cooperation of the three.

Description

Technical Field

[0001] This invention belongs to the field of X-ray source technology, and in particular relates to an X-ray source filament mounting structure and method. Background Technology

[0002] The filament of an X-ray source continuously wears down during operation and requires periodic replacement. In existing filament mounting structures, the filament holder is typically connected to the main body of the device only by a thread. When replacing the filament, it is difficult to precisely control the tightening depth and circumferential angle of the filament holder, resulting in inconsistent axial position of the filament relative to the main body after each replacement. This necessitates recalibrating the optical path, which is cumbersome and affects equipment efficiency. Furthermore, the threaded fit between the filament holder and the main body creates an axial clearance. During X-ray source operation, factors such as thermal expansion and mechanical vibration can cause changes in this clearance, leading to axial movement of the filament and consequently affecting the stability of the electron beam focal spot. Summary of the Invention

[0003] In view of this, the present invention aims to overcome the defects in the prior art and proposes an X-ray source filament mounting structure and method.

[0004] To achieve the above objectives, the technical solution created by this invention is implemented as follows: An X-ray source filament mounting structure, comprising: The main body of the device is equipped with an axial limiting part; The filament holder is connected to the main body of the device, and the lower end face of the filament holder abuts against the axial limiting part, forming an installation space between the filament holder and the main body of the device. The filament body is located within the installation space; An elastic preload member is disposed within the main body of the device. The top end of the elastic preload member abuts against the lower end face of the filament body to apply an axial elastic force to the filament body, causing the filament body to abut against the filament holder; and Locking element, used to fix the filament body relative to the filament holder.

[0005] Furthermore, the locking element is a fastening screw, which is radially inserted into the side wall of the filament holder.

[0006] Furthermore, the number of locking elements is at least two, and each locking element is evenly distributed along the circumference of the filament holder.

[0007] Furthermore, the elastic preload element is a round-headed spring plunger.

[0008] Furthermore, the filament holder is connected to the main body of the device by a threaded connection.

[0009] Furthermore, the axial limiting part is a limiting step provided on the inner wall of the main body of the device.

[0010] Furthermore, the filament body is provided with a hairpin filament and an electrode post.

[0011] Furthermore, the main body of the device is vertically provided with mounting holes for installing the elastic preload.

[0012] A method for installing an X-ray source filament includes the following steps: Place the filament body on the device body, so that the lower end face of the filament body abuts against the top of the elastic pre-tightening member provided in the device body; The filament holder is connected to the main body of the device, so that the filament body is confined within the installation space between the filament holder and the main body of the device, and the lower end face of the filament holder abuts against the axial limiting part of the main body of the device. The elastic pre-tightening member is compressed and pre-tightened, and an axial elastic force is applied to the filament body to press the filament body against the filament holder. Then, the filament body is fixed to the filament holder using locking devices to complete the installation.

[0013] Compared with existing technologies, the present invention has the following advantages: The device body of this invention is provided with an axial limiting part. The filament holder is connected to the device body, and its lower end face abuts against the axial limiting part, forming an installation space between the filament holder and the device body. The filament body is located within this installation space. An elastic pre-tightening member is provided inside the device body, with its top end abutting against the lower end face of the filament body, applying an axial elastic force to the filament body, causing the filament body to abut against the filament holder. A locking member then fixes the filament body and the filament holder relatively in place. Thus, each time the filament holder is installed, its lower end face abuts against the same axial limiting part, and the axial position of the filament body is uniquely determined by this axial limiting part. After replacing the filament, there is no need to recalibrate the optical path, achieving high-precision repeatability. Simultaneously, the axial elastic force continuously applied by the elastic pre-tightening member keeps the lower end face of the filament holder in a tight fit with the axial limiting part. Even if slight loosening occurs during operation due to thermal expansion and contraction or vibration, the elastic pre-tightening member can dynamically compensate, effectively eliminating axial clearance and ensuring long-term stability of the filament position. After the locking component fixes the filament body and the filament holder in relative position, the two become one, which not only prevents the filament body from moving around in the installation space, but also maintains the pre-tightening force of the elastic pre-tightening component, ensuring that the pre-tightening effect is continuous and effective. The operator only needs to connect the filament holder to the axial limiting part and fix it with the locking component. The installation position is determined by the structure itself, without relying on the operator's feel or visual judgment, which simplifies the assembly operation while ensuring positioning accuracy. Attached Figure Description

[0014] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A schematic diagram of the structure created by this invention; Figure 2 A schematic diagram of the filament body in this invention; Figure 3 A schematic diagram of the filament holder in this invention; Figure 4 This is a schematic diagram of the main body of the device in this invention; Figure 5 This is a schematic diagram of the decomposed structure of the present invention.

[0015] Explanation of reference numerals in the attached figures: 1. Main body of the device; 2. Round-headed spring plunger; 3. Filament body; 4. Filament holder; 5. Fastening screw; 6. Mounting hole; 7. Threaded part; 8. Limiting step; 9. First positioning hole; 10. Hairpin filament; 11. Pole post; 12. Second positioning hole; 13. Mating thread; 14. Positioning surface; 15. Fixing screw hole. Detailed Implementation

[0016] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, 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, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] like Figures 1 to 5 As shown, this invention provides an X-ray source filament mounting structure, mainly comprising a device body 1, a filament holder 4, a filament body 3, an elastic pretensioner, and a locking component. The device body 1 is made of metal and has certain structural strength and electrical conductivity. The device body 1 is provided with a threaded portion 7, a limiting step 8, and a first positioning hole 9 located at the center of the end face. The limiting step 8 is located on the upper part of the device body 1 and is lower than the top end face of the device body 1. This limiting step 8 constitutes an axial limiting portion, used to axially limit the mounting position of the filament holder 4. The device body 1 is also vertically provided with a mounting hole 6 for mounting the elastic pretensioner, which is preferably a threaded hole.

[0021] The filament holder 4 is provided with a mating thread 13, a positioning surface 14, a second positioning hole 12, and a fixing screw hole 15. The positioning surface 14 is the lower end face of the filament holder 4, and the fixing screw hole 15 is located on the side wall of the filament holder 4. The filament holder 4 is screwed into the device body 1 via the mating thread 13, engaging with the threaded portion 7 of the device body 1. When the filament holder 4 is screwed into place, the positioning surface 14 of the filament holder 4 abuts against the limiting step 8 of the device body 1, forming an axial limit; at this time, an installation space is formed between the filament holder 4 and the device body 1. The filament body 3 is located within the aforementioned installation space. The filament body 3 is provided with a hairpin filament 10 and an electrode post 11. The hairpin filament 10 is a structure in which a metal wire (such as a tungsten wire) is bent into a hairpin shape (V-shaped or U-shaped). In a micro-focal X-ray tube, its tip is used to emit a fine electron beam to obtain a micron-level focal spot size. The pole 11 is used to electrically connect the hairpin filament 10 to an external power source to supply power to the filament.

[0022] The first positioning hole 9 and the second positioning hole 12 are coaxially arranged. During installation, the images of the two positioning holes can be observed through a microscope, and coaxial alignment can be performed using the reference crosshairs of the microscope. Specifically, the center of the reference crosshairs of the microscope is aligned with the center of the first positioning hole 9 and the center of the second positioning hole 12, respectively, which ensures the coaxiality of the filament holder 4 and the main body 1 of the device, thereby ensuring the consistency of the filament axis after installation.

[0023] An elastic preload is disposed within the main body 1 of the device, located below the filament body 3. The top end of the elastic preload abuts against the lower end face of the filament body 3. In this embodiment, the elastic preload is preferably a round-headed spring plunger 2. This round-headed spring plunger 2 is a standard part, and its structure consists of a spring installed inside a threaded sleeve, which outputs elastic force through a ball head (ball). The round-headed spring plunger 2 is fixed in the mounting hole 6 of the main body 1 by a threaded connection, and its axial direction is parallel to the axis of the main body 1, with the ball head facing upward. During the process of screwing the filament holder 4 into the main body 1, the filament holder 4 moves downward, compressing the round-headed spring plunger 2 through the filament body 3; when the positioning surface 14 of the filament holder 4 abuts against the limiting step 8, it is screwed in place, and the round-headed spring plunger 2 is in a preset compressed state. At this time, the round-headed spring plunger 2 applies a vertically upward axial elastic force to the filament body 3, so that the filament body 3 always abuts against the filament holder 4.

[0024] The locking element is used to fix the filament body 3 relative to the filament holder 4 to prevent the filament body 3 from shifting relative to the filament holder 4 during operation due to factors such as vibration or thermal expansion. In this embodiment, the locking element is preferably a fastening screw 5, which is radially inserted into the fixing screw hole 15 on the side wall of the filament holder 4. Preferably, there are at least two fastening screws 5, and each fastening screw 5 is evenly distributed along the circumference of the filament holder 4. This arrangement allows for the application of a uniform radial locking force to the filament body 3 from multiple directions, ensuring that the filament body 3 is stably fixed within the filament holder 4 and preventing skewing of the filament body 3 due to unilateral locking.

[0025] Simultaneously, a uniform radial locking force is applied to the filament body by multiple circumferentially distributed fastening screws, ensuring that the axis of the filament body is coaxial with the axis of the filament holder. When the filament body 3 is installed into the mounting hole of the filament holder 4, the two are not tightly fitted, but rather a clearance is provided for easy installation. If a single-sided screw is used for tightening, this clearance would cause the filament body 3 to be pushed to one side, causing its axis to shift relative to the axis of the filament holder 4, thus affecting the directional consistency of the electron beam emitted by the filament. This invention addresses this by uniformly arranging at least two (preferably three) fastening screws 5 circumferentially on the filament holder 4, with each screw 5 applying a locking force to the filament body 3 simultaneously from different radial directions. During the tightening process, the locking forces of each screw 5 are balanced circumferentially, automatically positioning the filament body 3 at the center of the mounting hole of the filament holder 4, aligning the axis of the filament body 3 with the axis of the filament holder 4, thus achieving a coaxial fit between the two. This coaxial effect works in conjunction with the alignment of the first positioning hole 9 and the second positioning hole 12 under the aforementioned microscope assistance: the former ensures the coaxiality of the filament body 3 and the filament holder 4, while the latter ensures the coaxiality of the filament holder 4 and the device body 1. Together, they ensure the overall coaxial accuracy of the filament body 3 relative to the device body 1.

[0026] The mechanical transmission principle of this invention is as follows: After the round-headed spring plunger 2 is compressed, it generates an upward elastic restoring force. This elastic force acts directly on the lower end face of the filament body 3, pushing the filament body 3 upward and causing it to abut against the filament holder 4. Since the filament body 3 is radially fixed to the filament holder 4 by the fastening screw 5, the elastic force of the round-headed spring plunger 2 continuously acts on the filament body 3. Furthermore, the filament body 3 maintains a relatively fixed relationship with the filament holder 4 by the fastening screw 5. Therefore, the elastic force is transmitted to the filament holder 4, ensuring that the positioning surface 14 of the filament holder 4 always maintains a tight fit with the limiting step 8, thereby eliminating the axial clearance between the positioning surface 14 and the limiting step 8. In the actual working environment of an X-ray source, the equipment may experience thermal expansion and contraction due to temperature changes, or mechanical vibration due to the operation of the vacuum pump. Without this elastic pre-tightening effect, the threaded connection may gradually loosen, creating a small axial clearance between the filament holder and the step, leading to filament position displacement and blurred focal spots. The present invention, through the continuous elastic force provided by the round-headed spring plunger 2, can dynamically compensate for the slight deformation caused by thermal expansion or vibration, and always maintain the tight fit between the positioning surface 14 and the limiting step 8, ensuring that the axial position of the filament body 3 is uniquely determined by the limiting step 8 after each installation, thus achieving high-precision repeatable positioning.

[0027] During installation, first place the filament body 3 on the device body 1, so that the lower end face of the filament body 3 abuts against the top of the round-headed spring plunger 2; then screw the filament holder 4 into the threaded part 7 of the device body 1 through the mating thread 13. During the screwing process, the filament body 3 is gradually confined within the installation space between the filament holder 4 and the device body 1. Continue screwing until the positioning surface 14 of the filament holder 4 abuts against the limiting step 8; at this time, the round-headed spring plunger 2 is compressed to the preset state, applying axial elastic force to the filament body 3 to press it against the filament holder 4; finally, use the fastening screw 5 to radially lock and fix the filament body 3 and the filament holder 4 to complete the installation. It should be noted that the axial position of the filament body 3 within the installation space is not determined by the locking mechanism, but rather by the combined axial position of the limiting step 8 and the screwing depth of the filament holder 4. Once the lower end face of the filament holder 4 abuts against the limiting step 8, a rigid limit is formed. The elastic force of the round-headed spring plunger 2 only serves to eliminate gaps and does not change the already determined axial position. This feature allows the operator to obtain consistent axial positioning results simply by screwing the filament holder into its natural position (i.e., the lower end face contacts the limiting step 8), without relying on feel or experience to judge the degree of tightening.

[0028] Optionally, after the filament holder 4 is screwed into place, the images of the first positioning hole 9 on the main body 1 and the second positioning hole 12 on the filament holder 4 can be observed under a microscope. The circumferential angle of the filament holder 4 can be adjusted until the reference cross center of the microscope coincides with the center of the two positioning holes, ensuring the coaxiality of the filament holder 4 and the main body 1. Those skilled in the art will understand that this alignment step can be performed before the filament holder 4 is screwed into place, or it can be finely adjusted afterward. That is, since a certain circumferential clearance is unavoidable in the threaded fit, even if the lower end face of the filament holder 4 has contacted the limiting step 8, the circumferential angle of the filament holder 4 can still be finely adjusted within the allowable range of the thread clearance to ensure precise alignment of the two positioning holes, thereby ensuring that the axis of the filament body 3 is consistent with the axis of the main body 1. Through the above steps, the filament installation is completed.

[0029] This invention features an axial limiting part on the main body of the device. Each time the filament holder is screwed in and installed, its lower end face abuts against the same axial limiting part, ensuring that the axial position of the filament holder and the filament body is uniquely determined by this limiting part. When replacing the filament, simply screwing the filament holder back in until its lower end face contacts the step restores it to the same axial position as before replacement. This eliminates the need to recalibrate the optical path after each replacement, effectively improving maintenance efficiency and avoiding positioning deviations caused by human operation.

[0030] Based on this, the present invention applies a continuous axial elastic force to the filament body through an elastic preload, so that the filament body always abuts against the filament holder. Even if the X-ray source expands and contracts due to temperature changes or the threaded connection becomes slightly loose due to vibration during operation, the elastic preload can dynamically compensate for the looseness, so that the lower end face of the filament holder always maintains a tight fit with the axial limiting part, effectively eliminating the axial gap that may be generated by the threaded fit and ensuring the long-term stability of the filament position.

[0031] Meanwhile, this invention uses multiple fastening screws evenly distributed around the filament holder to simultaneously lock the filament body from different directions. Even with an assembly gap between the filament body and the filament holder, the evenly distributed locking forces balance each other circumferentially. Simultaneously, the filament body is automatically positioned at the center of the filament holder, ensuring their axes coincide. This coaxial effect, combined with the alignment of the two positioning holes under microscope assistance, guarantees the coaxiality of the filament body and the filament holder, as well as the coaxiality of the filament holder and the main body of the device. No additional alignment structure or alignment operation steps are required.

[0032] The three functions mentioned above—axial positioning (ensuring this through the step), axial pre-tightening (ensuring this through the elastic pre-tightening element), and radial locking (ensuring this through the fastening screw)—work together synergistically and are each completed independently by different components. Operators only need to screw the filament holder into its natural position and tighten the screws. The installation position is determined by the structure itself, eliminating the need for manual judgment or visual inspection, which is beneficial for mass production and rapid on-site replacement. Furthermore, all components of this invention are conventional mechanical parts, requiring no complex processing techniques or special materials, resulting in low cost, ease of manufacturing, and independence from the specific shape of the filament. This makes it suitable for filament installation in various types of X-ray sources, demonstrating good versatility and application value.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An X-ray source filament mounting structure, characterized in that, include: The main body of the device is equipped with an axial limiting part; The filament holder is connected to the main body of the device, and the lower end face of the filament holder abuts against the axial limiting part, forming an installation space between the filament holder and the main body of the device. The filament body is located within the installation space; An elastic pretensioner is disposed inside the main body of the device. The top end of the elastic pretensioner abuts against the lower end face of the filament body to apply an axial elastic force to the filament body, so that the filament body abuts against the filament holder. as well as Locking element, used to fix the filament body relative to the filament holder.

2. The X-ray source filament mounting structure according to claim 1, characterized in that: The locking element is a fastening screw, which is radially inserted into the side wall of the filament holder.

3. The X-ray source filament mounting structure according to claim 2, characterized in that: The number of locking elements is at least two, and each locking element is evenly distributed along the circumference of the filament holder.

4. The X-ray source filament mounting structure according to claim 1, characterized in that: The elastic preload component is a round-headed spring plunger.

5. The X-ray source filament mounting structure according to claim 1, characterized in that: The filament holder is connected to the main body of the device by a thread.

6. The X-ray source filament mounting structure according to claim 1, characterized in that: The axial limiting part is a limiting step provided on the inner wall of the main body of the device.

7. The X-ray source filament mounting structure according to claim 1, characterized in that: The filament body is provided with a hairpin filament and an electrode post.

8. The X-ray source filament mounting structure according to claim 1, characterized in that: The main body of the device is provided with vertical mounting holes for installing the elastic preload.

9. A method for installing an X-ray source filament, characterized in that, Includes the following steps: Place the filament body on the device body, so that the lower end face of the filament body abuts against the top of the elastic pre-tightening member provided in the device body; The filament holder is connected to the main body of the device, so that the filament body is confined within the installation space between the filament holder and the main body of the device, and the lower end face of the filament holder abuts against the axial limiting part of the main body of the device. The elastic pre-tightening member is compressed and pre-tightened, and an axial elastic force is applied to the filament body to press the filament body against the filament holder. Then, the filament body is fixed to the filament holder using locking devices to complete the installation.

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