Dynamic self-tightening syringe and syringe injector pump system

Abstract

The utility model discloses a kind of dynamic self-tightening syringe and syringe injection pump system, the piston outer circumferential surface of the syringe is equipped with multiple same direction inclined sawtooth, when piston reciprocates, the one-way rotation torque around syringe axis is generated by the interaction of inclined sawtooth and syringe cylinder inner wall, the direction of this one-way rotation torque is same with the tightening direction of syringe installed on injection pump, so as to realize the dynamic self-tightening effect of "tighter and tighter", effectively prevent thread connection loosening in high-frequency reciprocating use. The syringe injection pump system formed by the above-mentioned syringe forms the complete anti-loose and leakage prevention system of "accurate initial seal+continuous dynamic self-tightening", significantly improves the sealing reliability and measurement accuracy of molecular interaction instrument, liquid chromatograph and other precision analytical instruments under high-frequency reciprocating sampling scene.

Description

Technical Field

[0001] This utility model relates to the field of precision analytical instruments and medical devices, specifically to a syringe with dynamic self-tightening function and a syringe injection pump system including the above-mentioned syringe, which is particularly suitable for analytical instruments that require high-frequency reciprocating precision injection, such as molecular interaction analyzers (SPR), liquid chromatographs, and micro-injection pumps. Background Technology

[0002] In precision testing instruments such as molecular interaction analyzers, a syringe pump is often used in conjunction with a syringe to achieve precise injection and aspiration of minute amounts of liquid. The syringe is mounted on the syringe pump interface via a Luer thread. Inside the syringe is a piston that is driven by a plunger to reciprocate within the syringe barrel, completing the precise extraction and discharge of the liquid.

[0003] In existing technologies, the connection and seal between the syringe and the injection pump primarily rely on a sealing gasket (such as a Teflon gasket) at the syringe tip. Due to the high sealing requirements, this connection requires a tightening torque of approximately 0.1 N·m to ensure a reliable seal. However, the installation space for injection pumps is limited, making it impossible to use ordinary torque wrenches or similar tools; operators must tighten the screws by hand. The tightening force varies significantly among different operators, easily leading to overtightening that damages the threads or undertightening that causes leakage, making it difficult to uniformly control installation quality.

[0004] To address the issue of uncontrollable installation torque, existing solutions employ torque-limiting closure components. These components, through the cooperation of a stop and a motion limiter, achieve disengagement at a preset torque, thus preventing over-tightening. However, the control mechanism of this solution is typically integrated into the closure component, making the component and syringe often a single unit. This prevents the separation and reuse of the torque control tool and syringe, increasing consumable costs and causing resource waste in single-use scenarios.

[0005] More seriously, the syringe pumps in precision testing instruments such as molecular interaction apparatuses require frequent piston-pulling (several times or even more per second). During long-term high-frequency reciprocating motion, the threaded connections will gradually loosen due to continuous alternating loads and vibrations. Once the threads loosen, it will lead to liquid leakage or the entry of outside air into the measuring liquid, causing the measurement data to drift and deviate, seriously affecting the measurement accuracy and repeatability of the instrument.

[0006] To address the issue of loosening under high-frequency use, some research has attempted to incorporate one-way meshing teeth between the syringe barrel's front end and the connector, allowing the connector to rotate only in the forward direction and preventing it from detaching. This approach, by placing the one-way meshing structure at the connection between the syringe and the connector, achieves static locking—once assembled, the meshing teeth prevent reverse rotation—but it lacks the ability to continuously generate a tightening force during use. Furthermore, this approach requires complex mating structures on both the syringe barrel and the connector, increasing the difficulty and cost of syringe manufacturing.

[0007] Therefore, there is an urgent need for a syringe pump sealing solution that can automatically prevent thread loosening during long-term, high-frequency use, and this solution should minimize consumable costs. Utility Model Content

[0008] The present invention aims to provide a dynamic self-tightening syringe, a torque control component, and a syringe injection pump system to solve the above-mentioned problems.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A syringe for detachable mounting to an injection pump, comprising: The syringe barrel has a connecting part at its front end for connecting with the syringe pump mounting interface; The piston is fixedly installed at the front end of the push rod and can reciprocate within the syringe barrel, forming a sealed fit between the piston and the inner wall of the syringe barrel. The piston has multiple serrations that are inclined in the same direction at its end. The outer peripheral surface of the serrations is flush with the outer peripheral surface of the piston, and the extension direction of the serrations is parallel to the axial direction of the syringe barrel. The piston and the syringe barrel are slidably interference-fitted. The inclination direction of the saw teeth is set such that when the push rod drives the piston to reciprocate within the syringe barrel, the piston generates a unidirectional rotational torque around the syringe axis, and the direction of the unidirectional rotational torque is the same as the tightening direction of the syringe mounted on the injection pump.

[0010] With the above structure, in each stroke of the piston's reciprocating motion, the interaction between the inclined serrations on the piston's outer circumference and the inner wall of the syringe barrel converts the piston's axial movement into a circumferential rotational force. Because the serrations are inclined in the same direction, regardless of whether the piston advances forward or retracts backward, the resulting circumferential force always points in the same direction, towards the tightening direction of the syringe. Therefore, in each reciprocating motion, the piston applies a small but continuous unidirectional tightening torque to the syringe. With repeated use, the threaded connection between the syringe and the injection pump will not loosen due to vibration and alternating loads; instead, it will become increasingly tighter with use.

[0011] Furthermore, the inclination angle of the saw teeth is 15° to 45°; the shape of the saw teeth is at least one of triangle, trapezoid, or arc.

[0012] In a preferred embodiment of the syringe technical solution, the inclination angle of the serrations is 15° to 45°, more preferably 30°. The inclination angle is optimized to achieve the best balance between the generated tightening torque and the piston movement resistance: an excessively large inclination angle, while generating a large tightening torque, increases piston movement resistance; an excessively small inclination angle results in insufficient tightening torque. Experiments have shown that a 30° inclination angle can generate sufficient tightening torque while maintaining low piston movement resistance. Triangular serrations have sharper tooth tips and a smaller contact area with the syringe barrel wall, thus generating lower sliding friction resistance; trapezoidal serrations have a flat surface at the tooth tip, resulting in more uniform contact pressure with the barrel wall and better wear resistance; arc-shaped serrations achieve a balance between the two.

[0013] Furthermore, the serrations are arranged in multiple rings along the axial direction on the outer circumference of the piston, with adjacent serrations staggered in the circumferential direction. The multiple rings of serrations and the staggered arrangement provide a more uniform circumferential force distribution, preventing the piston from tilting during movement and making the rotational motion smoother.

[0014] Furthermore, the piston is provided with a plurality of the serrations at least at its upper end and / or lower end.

[0015] Furthermore, it also includes a torque control component for controlling the tightening torque of the syringe when mounted on the injection pump, the torque control component comprising: An elastic friction pad can be fitted onto the outer periphery of the syringe; A torque wrench is capable of being fitted onto the elastic friction pad and engaging with it in frictional contact. The static friction between the torque wrench and the elastic friction pad corresponds to a preset torque value. When the tightening torque reaches the preset torque value, relative sliding occurs between the torque wrench and the elastic friction pad, thereby limiting the maximum tightening torque.

[0016] With the above structure, when installing the syringe by hand, the operator only needs to place the elastic friction pad on the syringe neck, place the torque wrench on the elastic friction pad, and rotate it. When the preset torque is reached, the torque wrench will slip, at which point the syringe has obtained a precise initial sealing force. After the operation is completed, the torque wrench can be removed from the elastic friction pad, and the elastic friction pad can also be removed from the syringe. The torque control component can be reused for the installation of subsequent syringes, realizing the separation and reuse of the torque control tool and the syringe.

[0017] Furthermore, the inner diameter of the elastic friction pad is interference-fitted with the outer diameter of the syringe neck, with an interference amount of 0.05mm to 0.15mm. This ensures that the elastic friction pad is securely installed on the syringe and will not slip relative to the syringe during tightening, thereby ensuring that the torque can be reliably transmitted from the torque wrench to the syringe.

[0018] Furthermore, the outer peripheral surface of the elastic friction pad is provided with a knurled or corrugated structure. This increases the coefficient of friction between the pad and the inner wall of the torque wrench, while making the slippage torque more uniform and smooth, and improving the clarity of the tactile feedback during operation.

[0019] Furthermore, the inner wall of the torque wrench is provided with a toothed structure, and the outer periphery of the elastic friction pad is provided with corresponding toothed grooves. When the torque exceeds a preset value, the toothed structure undergoes elastic deformation and disengages from the toothed grooves. Compared with friction slippage, this solution has higher torque accuracy and better reusability.

[0020] Furthermore, the preset torque value is 0.08 N·m to 0.12 N·m. This torque value is determined comprehensively based on the compression characteristics of the syringe sealing gasket, the thread friction coefficient, and the anti-loosening requirements in the Luer connection standard.

[0021] This utility model also provides a syringe injection pump system, including: The syringe described in any of the preceding claims, wherein the inclined serrations of the syringe are used to continuously generate a tightening torque during the reciprocating motion of the syringe after it is mounted on the injection pump.

[0022] Furthermore, it also includes any of the torque control components described above; The torque control component is used to mount the syringe onto the injection pump and control the tightening torque.

[0023] Furthermore, the initial tightening torque of the syringe installed on the injection pump is limited to a preset torque value by the torque control component; during use, the inclined serrations on the outer circumference of the piston convert the reciprocating axial motion into a unidirectional rotational torque, causing the installation torque of the syringe to gradually increase during use.

[0024] Through the synergistic effect of the above systems, during the installation phase: the torque control component achieves precise initial sealing, ensuring the syringe's initial sealing surface is in optimal compression, preventing both initial leakage due to insufficient torque and seal failure due to excessive torque; during the usage phase: the syringe's own inclined serrated dynamic self-tightening structure continuously compensates for any possible minor loosening, ensuring the syringe maintains optimal sealing throughout its entire lifespan. These two elements form a complete anti-loosening and leak-proof system of "precise initial sealing + continuous dynamic self-tightening," fundamentally solving the sealing reliability problem of syringe pumps in high-frequency reciprocating use. Attached Figure Description

[0025] Figure 1 : Schematic diagram of the overall structure of the syringe injection pump system; Figure 2 : A schematic diagram of the overall structure of the syringe; Figure 3 : A cross-sectional view of a syringe; Figure 4 : Figure 3 Enlarged view of section A in the middle; Figure 5 A schematic diagram of the piston structure, showing the structure and tilt angle of the inclined serrations; Figure 6 : An exploded view of a syringe, showing the syringe barrel, piston, and plunger; Figure 7 : A cross-sectional view of the syringe barrel, piston, and plunger. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the various embodiments of this utility model will be described in detail below. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this utility model to help readers better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and with various changes and modifications based on the following embodiments.

[0028] Reference Figures 1 to 7 A syringe for detachable mounting to an injection pump, comprising: The syringe barrel 02 has a connecting part 021 (e.g., external thread) at its front end, which is used to connect with the mounting interface (e.g., internal thread) of the syringe pump 01. Piston 03 is fixedly installed at the front end of push rod 04 and can reciprocate within syringe barrel 02. Piston 03 and the inner wall of syringe barrel 02 form a sealing fit. The end of piston 03 is provided with multiple serrations 031 that are inclined in the same direction. The outer peripheral surface of serration 031 is flush with the outer peripheral surface of piston 03, and the extension direction of serration 031 is parallel to the axial direction of syringe barrel 02. Piston 03 and syringe barrel 02 are slidably interference fit. The inclination direction of the sawtooth 031 is set as follows: when the push rod 04 drives the piston 03 to reciprocate in the syringe barrel, the sawtooth 031 will be subjected to the frictional resistance of the inner wall of the syringe barrel 02, resulting in an elastic deformation in the same direction as the inclination direction of the sawtooth. The piston 03 is generally made of an elastic material such as rubber. After deformation, it will be affected by elasticity and try to return to its original shape. This elastic force generates a force between the piston 03 and the syringe barrel 02 that causes them to rotate relative to each other. Since the other end of the push rod 04 away from the piston 03 is restricted by the push assembly of the injection pump and cannot rotate, the piston 03 generates a unidirectional rotational torque around the axis of the syringe. The direction of the unidirectional rotational torque is the same as the tightening direction of the syringe mounted on the injection pump, and this torque drives the syringe barrel 02 to rotate, and keeps its upper end connection 021 in a continuously tightened state with the injection pump 01 mounting port. In the example shown in the figure, piston 03 is a cup-shaped body with a blind hole. The front end of push rod 04 has a stepped piston connection part 041. The sealing ring 042 is fitted in the annular groove provided in the piston connection part 041. The piston connection part 041, including the sealing ring 042, is pressed into the blind hole of piston 03. The piston 03 is prevented from falling off by the frictional force between the piston and the inner wall of the piston being greater than the frictional force between piston 03 and the inner wall of syringe barrel.

[0029] Through the aforementioned structure, in each stroke of the piston's reciprocating motion, the interaction between the inclined serrations 031 on the piston's outer circumference and the inner wall of the syringe barrel converts the piston's axial movement into a circumferential rotational force. Because the serrations are inclined in the same direction, regardless of whether the piston advances forward (towards the syringe outlet) or retracts backward (towards the syringe tail), the resulting circumferential force always points in the same direction, towards the tightening direction of the syringe. Therefore, in each reciprocating motion, the piston applies a small but continuous unidirectional tightening torque to the syringe. With accumulated use, the threaded connection between the syringe and the injection pump will not loosen due to vibration and alternating loads; instead, it will become increasingly tighter with use.

[0030] Furthermore, the inclination angle of the serration 031 is 15° to 45°, preferably 30°; the shape of the serration 031 is at least one of triangle, trapezoid, or arc. In a preferred embodiment of the syringe technical solution, the inclination angle of the serration is 15° to 45°, more preferably 30°. The inclination angle is optimized to achieve the best balance between the generated tightening torque and the piston movement resistance: an excessively large inclination angle can generate a large tightening torque, but it will increase the piston movement resistance; an excessively small inclination angle will result in insufficient tightening torque. An inclination angle of 30° has been experimentally proven to maintain low piston movement resistance while generating sufficient tightening torque. Triangular serrations have sharper tooth tips and a smaller contact area with the inner wall of the syringe barrel, thereby generating lower sliding friction resistance; trapezoidal serrations have a flat surface at the tooth tip, resulting in more uniform contact pressure with the barrel wall and better wear resistance; arc-shaped serrations achieve a balance between the two.

[0031] Furthermore, the serrations 031 are arranged in multiple rings along the axial direction on the outer circumference of the piston 03, with adjacent serrations staggered in the circumferential direction. The multiple rings of serrations and the staggered arrangement can provide a more uniform circumferential force distribution, prevent the piston from deflecting during movement, and make the rotational motion smoother.

[0032] Furthermore, the piston 03 is provided with a plurality of the serrations 031 at least at its upper end and / or lower end.

[0033] Furthermore, it also includes a torque control component 05 for controlling the tightening torque of the syringe when mounted on the injection pump. The torque control component 05 includes: The elastic friction pad 051 can be fitted onto the outer periphery of the syringe; The torque wrench 052 can be fitted onto the elastic friction pad 051 and engage in frictional contact with the elastic friction pad 051. The static friction between the torque wrench 052 and the elastic friction pad 051 corresponds to a preset torque value. When the tightening torque reaches the preset torque value, relative sliding occurs between the torque wrench 052 and the elastic friction pad 051, thereby limiting the maximum tightening torque.

[0034] With the above structure, when installing the syringe by hand, the operator only needs to place the elastic friction pad on the syringe neck, place the torque wrench on the elastic friction pad, and rotate it. When the preset torque is reached, the torque wrench will slip, at which point the syringe has obtained a precise initial sealing force. After the operation is completed, the torque wrench can be removed from the elastic friction pad, and the elastic friction pad can also be removed from the syringe. The torque control component can be reused for the installation of subsequent syringes, realizing the separation and reuse of the torque control tool and the syringe.

[0035] Furthermore, the inner diameter of the elastic friction pad 051 is interference-fitted with the outer diameter of the syringe neck, with an interference amount of 0.05mm to 0.15mm. This ensures that the elastic friction pad is securely installed on the syringe and will not slip relative to the syringe during tightening, thereby ensuring that the torque can be reliably transmitted from the torque wrench to the syringe.

[0036] Furthermore, the outer peripheral surface of the elastic friction pad 051 is provided with a knurled or corrugated structure. This increases the coefficient of friction between the pad and the inner wall of the torque wrench, while making the slippage torque more uniform and smooth, and improving the clarity of the tactile feedback during operation.

[0037] Furthermore, the inner wall of the torque wrench 052 is provided with a toothed structure, and the outer periphery of the elastic friction pad 051 is provided with corresponding toothed grooves. When the torque exceeds a preset value, the toothed structure undergoes elastic deformation and disengages from the toothed grooves. Compared with friction slippage, this solution has higher torque accuracy and better reusability.

[0038] Furthermore, the preset torque value is 0.08 N·m to 0.12 N·m, preferably 0.1 N·m. This torque value is determined comprehensively based on the compression characteristics of the syringe sealing gasket, the thread friction coefficient, and the anti-loosening requirements in the Luer connection standard.

[0039] This utility model also provides a syringe injection pump system, including: The syringe described in any of the above.

[0040] The torque control component is used to install the syringe onto the injection pump 01 and control the tightening torque. The inclined serrations 031 of the syringe are used to continuously generate tightening torque during the reciprocating motion of the syringe after it is installed on the injection pump.

[0041] Furthermore, the initial tightening torque of the syringe installed on the injection pump 01 is limited to a preset torque value by the torque control component 05; during use, the inclined sawtooth 031 on the outer circumference of the piston 03 converts the reciprocating axial motion into a unidirectional rotational torque, causing the installation torque of the syringe to gradually increase during use.

[0042] Through the synergistic effect of the above systems, during the installation phase: the torque control component achieves precise initial sealing, ensuring the syringe's initial sealing surface is in optimal compression, preventing both initial leakage due to insufficient torque and seal failure due to excessive torque; during the usage phase: the syringe's own inclined serrated dynamic self-tightening structure continuously compensates for any possible minor loosening, ensuring the syringe maintains optimal sealing throughout its entire lifespan. These two elements form a complete anti-loosening and leak-proof system of "precise initial sealing + continuous dynamic self-tightening," fundamentally solving the sealing reliability problem of syringe pumps in high-frequency reciprocating use.

[0043] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. These embodiments are only used to explain the present invention and do not constitute any limitation on the scope of protection of the present invention.

[0044] In some syringe embodiments, a syringe with a dynamic self-tightening function is provided.

[0045] Syringe barrel 02: Made of medical-grade polypropylene (PP), with an external thread at the front end conforming to ISO 594 standard Luer male thread, and a standard Luer taper (6% taper). The inner wall smoothness of the syringe barrel Ra≤0.4μm ensures smooth piston movement and good sealing.

[0046] Piston 03: The material is thermoplastic elastomer (TPE), with a Shore A hardness of 75. The interference fit between the outer diameter of the piston and the inner diameter of the syringe barrel is 0.20 mm. In this example, both ends of piston 03 have 12 inclined serrations 031 circumferentially arranged (or one end alone) on its outer periphery. The serrations are inclined at a 30° angle to the right when viewed from the tail to the head of the piston. The serrations are evenly spaced in a circle along the axial direction on the outer periphery of the piston. The serrations are trapezoidal in shape, with beveled sides and rounded corners (R0.05 mm) at the root to reduce stress concentration.

[0047] Push rod 04: The cross-section is a cross-shaped structure (it can also be a cylindrical structure or other columnar structures) to ensure sufficient axial stiffness and bending stiffness. The front end is provided with a groove to be fixedly connected to the piston, and the rear end is provided with a connecting part to cooperate with the injection pump drive mechanism.

[0048] Instructions for use: Install the piston onto the plunger, then insert the plunger and piston into the syringe barrel. Screw the external thread of the syringe tip into the Luer internal thread of the syringe pump, tightening to the appropriate initial sealing torque before use. Driven by the syringe pump, the plunger drives the piston to reciprocate within the syringe barrel. The inclined serrations convert the axial force of each reciprocating motion into a unidirectional tightening torque, ensuring the syringe remains tightly tightened during use.

[0049] The syringe of this embodiment was installed on the injection pump of the molecular interaction apparatus using a precision torque wrench with an initial torque of 0.10 N·m. A 100,000-cycle reciprocating test was then performed, measuring the change in installation torque to verify the positive change in installation torque and clarify its effectiveness in preventing loosening. Throughout the test, there was no liquid leakage or air ingress at the connection between the syringe and the injection pump, no obvious scratches on the inner wall of the syringe barrel, and no significant wear on the piston teeth.

[0050] In some embodiments, the difference from the above embodiments lies in the parameter design of the inclined serrations on the piston.

[0051] In this embodiment, the inclination angle of the inclined serrations on the outer circumference of the piston is set to 20° (instead of 30° in Embodiment 1), and the serration shape is triangular (e.g., Figure 2 and Figure 3 As shown (not trapezoidal). Triangular serrations have sharper tooth tips, making it easier to deform upon contact with the inner wall of the syringe barrel. This generates friction that causes the syringe barrel to rotate. The magnitude of this friction depends on the dimensions of the triangle, such as the width of the base, the height of the triangle, and the angle of inclination. By adjusting these parameters, the piston movement resistance can be adjusted to better suit ultra-precision injection scenarios requiring extremely low injection resistance and extremely high motion accuracy.

[0052] In some embodiments, the torque control component 05 is used for precise torque control during syringe installation, and includes: Elastic friction pad 051: The inner diameter is interference-fitted with the outer diameter of the syringe neck, with an interference amount of 0.10mm. The material is silicone rubber with a Shore A hardness of 60. The outer circumferential surface of the elastic friction pad has axially extending knurling; the knurling depth and pitch can be selected as needed, for example, 0.1mm with a pitch of 0.5mm, to improve the stability of the friction coefficient with the inner wall of the torque wrench. The elastic friction pad is manufactured by compression molding or injection molding.

[0053] Torque wrench 052: It has a cylindrical structure with an inner diameter of 11.8mm (slightly smaller than the outer diameter of the elastic friction pad at 12mm, forming an interference fit). Its axial length can be the same as that of elastic friction pad 051. The outer surface has anti-slip textures to facilitate manual rotation. The slippage torque of the torque wrench is calibrated to 0.1N·m ± 0.005N·m. The slippage torque is determined by a combination of the contact area between the elastic friction pad and the inner wall of the torque wrench, the coefficient of friction, and the interference fit. The torque wrench is preferably made of engineering plastics (such as polyoxymethylene (POM) or polycarbonate (PC), which can be mass-produced through injection molding at a low cost.

[0054] The procedure is as follows: The operator screws the external thread of the syringe tip into the internal thread of the syringe pump. After initially tightening by hand until slight contact resistance is felt, the elastic friction pad is placed over the syringe neck. Then, the torque wrench is placed over the elastic friction pad, and a uniform rotational force is applied. When the operator hears a "click" sound (slipping sound) and feels a sudden decrease in resistance, it indicates that the tightening torque has reached the preset value of 0.1 N·m. Stop rotating and remove the torque wrench. The elastic friction pad can be left on the syringe or removed. Leaving it on provides additional frictional damping to prevent loosening, but a new elastic friction pad must be used each time the syringe is changed, or the original elastic friction pad must be ensured to be in good condition.

[0055] In some embodiments, the torque control component may employ the following alternatives.

[0056] The difference between this embodiment and the above embodiments lies in the implementation method of the torque control component.

[0057] In this embodiment, the torque wrench uses a toothed slip structure instead of a friction slip structure. Six elastic cantilever teeth are evenly distributed circumferentially on the inner wall of the torque wrench. The root of each cantilever tooth is integrally formed with the torque wrench body, and the free end of the cantilever tooth protrudes inward. Six axial toothed grooves are provided at corresponding positions on the syringe neck. The inner wall of the elastic friction pad mates with the syringe neck, while the outer wall remains smooth.

[0058] Initially, the cantilever teeth of the torque wrench are inserted into the corresponding grooves on the syringe neck, forming a circumferential lock. When the operator rotates the torque wrench, the cantilever teeth drive the syringe to rotate and tighten via the grooves. When the tightening torque reaches the preset value of 0.1 N·m, the cantilever teeth undergo elastic deformation and disengage from the grooves, allowing the torque wrench to spin freely relative to the syringe. The operator senses this free spin and knows that the preset torque has been reached, then stops rotating.

[0059] Compared to friction slippage, the toothed slippage solution offers higher torque accuracy (tolerance controllable within ±0.002 N·m) and better reusability (the cantilever teeth retain elasticity even after more than 1000 disengagements). However, the manufacturing cost is slightly higher, and it requires tooth groove machining on the syringe neck. This solution is suitable for applications with higher torque accuracy requirements.

[0060] like Figure 1 As shown, an example of a syringe injection pump system is as follows: This embodiment provides a syringe injection pump system that integrates the above-described syringe and torque control component embodiment combination.

[0061] Injection pump 01: It adopts Luer internal thread interface with an interface depth of 8mm. The interface material can be selected as needed, such as 316L stainless steel.

[0062] Syringe: Same as one of the syringe embodiments described above.

[0063] Torque control component: Same as one of the aforementioned torque control component embodiments.

[0064] Installation steps: Install the piston onto the push rod, then insert the push rod and piston into the syringe barrel. Place the elastic friction pad onto the neck of the syringe barrel. Screw the external thread of the syringe tip into the Luer internal thread interface of the injection pump, initially tightening by hand until slight contact resistance is felt. Place the torque wrench on the elastic friction pad and apply a uniform rotational force. When the torque wrench slips (a "click" sound is heard and the resistance suddenly decreases), it indicates that the tightening torque has reached the preset value of 0.1 N·m; stop rotating. Remove the torque wrench. The elastic friction pad can be left on the syringe or removed—in this embodiment, the torque control component is removed for later use; the elastic friction pad's retention or replacement depends on its condition.

[0065] Usage Instructions: Activate the syringe pump drive mechanism. The push rod drives the piston to reciprocate within the syringe barrel. The inclined serrations on the piston's outer circumference convert the reciprocating axial motion into unidirectional rotational torque, ensuring the syringe remains continuously tightened during use. Due to the innovative piston structure, the syringe installation torque continuously increases from the initial 0.10 N·m, preventing loosening of the connection and eliminating any leakage or air intake. In a comparative test, the same device using a standard syringe (without the inclined serrated structure) also had an initial torque of 0.10 N·m, but after prolonged cycling, the torque continuously decreased, eventually resulting in a minor leak, forcing the termination of the test.

[0066] Replacement procedure: After use, unscrew the syringe from the syringe pump and discard it. The torque control assembly (including a torque wrench, optionally including a flexible friction pad) can be retained for installation of the next syringe. The flexible friction pad can be replaced individually when it wears out after multiple uses.

Claims

1. A dynamic self-tightening injector for detachable mounting on an injection pump (01), comprising: The syringe barrel (02) has a connecting part (021) at its front end for connecting with the mounting interface of the syringe pump (01); The piston (03) is fixedly installed at the front end of the push rod (04) and can reciprocate within the syringe barrel (02). A sealing fit is formed between the piston (03) and the inner wall of the syringe barrel (02). Its features are, The piston (03) is provided with a plurality of serrations (031) that are inclined in the same direction at its end. The outer peripheral surface of the serrations (031) is flush with the outer peripheral surface of the piston (03), and the extension direction of the serrations (031) is parallel to the axial direction of the syringe barrel (02). The piston (03) and the syringe barrel (02) are slidably interference fit. The inclination direction of the saw teeth (031) is set such that when the push rod (04) drives the piston (03) to reciprocate in the syringe barrel, the piston (03) generates a unidirectional rotational torque around the syringe axis, and the direction of the unidirectional rotational torque is the same as the tightening direction of the syringe mounted on the injection pump.

2. The dynamic self-tightening injector according to claim 1, characterized in that, The inclination angle of the saw teeth (031) is 15° to 45°; the shape of the saw teeth (031) is at least one of triangle, trapezoid or arc.

3. The dynamic self-tightening injector according to claim 1, characterized in that, The saw teeth (031) are arranged in multiple rings along the axial direction on the outer periphery of the piston (03), and adjacent saw teeth are staggered in the circumferential direction.

4. The dynamic self-tightening injector according to claim 1, characterized in that, The piston (03) is provided with a plurality of the serrations (031) at least at the upper end and / or the lower end.

5. The dynamic self-tightening injector according to any one of claims 1-4, characterized in that, It also includes a torque control component (05) for controlling the tightening torque of the syringe when mounted on the injection pump, the torque control component (05) comprising: The elastic friction pad (051) can be fitted onto the outer periphery of the syringe; A torque wrench (052) can be fitted onto the elastic friction pad (051) and engage with the elastic friction pad (051) in frictional contact. The static friction between the torque wrench (052) and the elastic friction pad (051) corresponds to a preset torque value. When the tightening torque reaches the preset torque value, relative sliding occurs between the torque wrench (052) and the elastic friction pad (051), thereby limiting the maximum tightening torque.

6. The dynamic self-tightening injector according to claim 5, characterized in that, The outer peripheral surface of the elastic friction pad (051) is provided with a knurled or corrugated structure.

7. The dynamic self-tightening injector according to claim 5, characterized in that, The inner wall of the torque wrench (052) is provided with a toothed structure, and the outer periphery of the elastic friction pad (051) is provided with a corresponding toothed groove. When the torque exceeds the preset value, the toothed structure undergoes elastic deformation and disengages from the toothed groove.

8. The dynamic self-tightening injector according to claim 5, characterized in that, The preset torque value is 0.08 N·m to 0.12 N·m.

9. A syringe injection pump system, characterized in that, include: The syringe according to any one of claims 1 to 8, wherein the inclined serrations (031) of the syringe are used to continuously generate a tightening torque during the reciprocating motion of the syringe after it is mounted on the injection pump.

10. The syringe injection pump system according to claim 9, characterized in that, The initial tightening torque of the syringe installed on the injection pump (01) is limited to a preset torque value by the torque control component (05); during use, the inclined saw teeth (031) on the outer circumference of the piston (03) convert the reciprocating axial motion into a unidirectional rotational torque, so that the installation torque of the syringe gradually increases during use.

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