A quantitative liquid adding device and system

Abstract

The present invention discloses a quantitative liquid adding device and system, including a frame, the frame is provided with a first slide groove for axial movement of a detachable sliding assembly, the sliding assembly is connected to a motor through a screw shaft; a nut assembly is provided inside the sliding assembly, the nut assembly includes a screw sleeve and a spline sleeve, the screw sleeve and the spline sleeve are both threadedly connected and are respectively connected to the screw shaft, the screw sleeve and the spline sleeve are coaxially slidably connected and cooperate with the screw shaft; a spring is provided on the outer wall of the screw sleeve, one end of the screw sleeve has a screw nut, and the other end has a limit sleeve, the spring is used to support the screw nut and the limit sleeve. It can make the screw and the screw nut slide with no gap and high precision, achieve the minimum friction force, the lowest kinetic energy loss, the highest instantaneous speed by clearance fit, and maximize the low loss and high response characteristics of the stepping motor.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic precise liquid adding, and in particular to a quantitative liquid adding device and system. Background Art

[0002] In the field of automatic precision liquid addition in the testing industry, syringes are commonly used for liquid transfer, but they are different in driving structure and precision time efficiency. With the continuous improvement of product testing efficiency, the frequency of precise liquid addition per unit time is getting higher and higher (referred to as high time efficiency). At present, the mainstream precision liquid addition in the market is the stepper motor driven screw nut type mechanism, which gradually replaces the stepper motor driven gear mechanism or belt mechanism to achieve liquid transfer.

[0003] Whether it is a stepper motor, an inertial stepper motor or an external drive stepper motor, they will all produce large friction or average accuracy, so they cannot fully meet the detection requirements of high response, high efficiency and high accuracy. In order to make the accuracy as accurate as possible, the current common practice is to drive the liquid to be sucked in by software, and then spit out the liquid slightly, and use the reverse action to eliminate the mechanical clearance between the lead screw nut and the lead screw to achieve higher accuracy and repeatability. Summary of the invention

[0004] The object of the present invention is to provide a quantitative liquid adding device, which can make the lead screw and the lead screw nut slide without clearance and with high precision, realize the minimum friction force, the lowest kinetic energy loss, the highest instantaneous speed through clearance fit, and maximize the low loss and high response characteristics of the stepping motor.

[0005] The embodiment of the present invention is achieved as follows:

[0006] The present application provides a quantitative liquid adding device, including a frame, the frame is provided with a first sliding groove for axial movement of a detachable sliding component, the sliding component is connected to a motor through a screw shaft; a nut component is provided inside the sliding component, the nut component includes a screw sleeve and a spline sleeve, the screw sleeve and the spline sleeve are both threadedly connected and are respectively connected to the screw shaft, the screw sleeve and the spline sleeve are coaxially slidably connected and cooperate together on the screw shaft; a spring is provided on the outer wall of the screw sleeve, one end of the screw sleeve has a screw nut, and one end of the spline nut has a limit sleeve, the spring is used to support the screw nut and the limit sleeve.

[0007] The existing technology generally uses syringes to transfer liquids, but the drive structure and accuracy and time efficiency are different. At present, the mainstream precise liquid addition in the market is a stepper motor driven screw nut mechanism, which gradually replaces the stepper motor driven gear mechanism or belt mechanism to achieve liquid transfer. However, the use of these types of motors may be complex in structure, have large friction, or have average accuracy, and cannot fully meet the detection requirements of high response, high efficiency and high precision.

[0008] In order to eliminate the influence of the radial clearance of the screw nut during movement on the radial shear force of the injection rod and to keep the straightness of the injection rod as much as possible, the present invention installs a linear guide rail on one side or both sides of the screw rod for directional positioning.

[0009] In summary of the technical solutions provided above, in some possible implementations, the sliding assembly includes a sliding plate, one end of which is detachably mounted on the lead screw nut, and the other end of which is slidably engaged with the first sliding groove.

[0010] In the embodiment of the present application, the sliding plate is turned to the external drive stepper motor, the anti-backlash nut is tightened on the lead screw shaft, and the hexagon socket head screw is tightened on the side of the sliding plate.

[0011] Based on the technical solutions provided above, in some possible implementations, the sliding plate has a threaded assembly and a positioning plate connected to the threaded assembly, the positioning plate is slidably connected to the first sliding groove, and the threaded assembly is detachably mounted on the screw shaft; the threaded assembly is connected to the screw nut, and the inner hole on the threaded assembly is mounted on the screw shaft.

[0012] In the embodiments of the present application, the contact surface of the slide groove is small, which will reduce the corresponding friction and ensure a certain strength.

[0013] Based on the technical solutions provided above, in some possible implementations, one end of the positioning plate has a connecting portion, and the other end has an optocoupler trigger portion; the optocoupler trigger portion is adapted to the photoelectric switch provided on the frame; a sliding portion that can slideably cooperate with the first slide groove is provided between the connecting portion and the optocoupler trigger portion.

[0014] In an embodiment of the present application, the connecting part adopts a U-shaped body structure, and a corresponding positioning hole and a positioning hole boss are provided on the U-shaped structure. The other end is an optical coupler trigger part. When it is separated from the photoelectric switch, the infrared device on the photoelectric switch is triggered and it is in a moving state.

[0015] In summary of the technical solutions provided above, in some possible implementations, the sliding portion has a first sliding surface, both sides of the first sliding surface have yielding areas, and the yielding areas are inclined surface structures.

[0016] In an embodiment of the present application, the inclined surface structure is a chamfer, and the inclined surface prevents the syringe from being abnormal, the slide plate is stuck to the aluminum alloy angle, and prevents abnormal surface contact from causing angle damage.

[0017] In summary, in some possible implementations, the frame includes a first plate, a second plate and a third plate, the second plate is vertically connected between the first plate and the third plate; a bearing pressure plate is provided on the side of the third plate away from the first plate, the screw shaft passes through the thread in the sliding assembly on the bearing pressure plate, and the bearing pressure plate is fastened to the third plate by a second screw.

[0018] In an embodiment of the present application, the second plate is vertically connected between the first plate and the third plate, the first plate is provided with a bearing mounting hole, and the third plate is provided with a motor boss mounting hole, both of which can be used to install the bearing mounting holes.

[0019] In summary of the technical solutions provided above, in some possible implementations, a waterproof plate is provided above the motor, and the waterproof plate is perpendicular to the top surface of the motor.

[0020] In the embodiment of the present application, the waterproof sheet prevents water from falling and damaging the motor.

[0021] In summary of the technical solutions provided above, in some possible implementations, an optical coupler mounting position is provided on the inner wall of the second plate, and the optical coupler mounting position fixes the photoelectric switch to the side wall of the frame through a first screw, and the photoelectric switch is located below the motor.

[0022] In the embodiment of the present application, the origin optical coupler is installed so that the sliding plate as the photoelectric switch trigger plate is away from the arc surface of the sliding plate, which is more conducive to mechanical processing and production.

[0023] A quantitative liquid adding system comprises an outer plate, wherein one side of the outer plate away from the screw shaft is tightly fitted with the other side of the frame; an electromagnetic valve assembly is provided at the upper end of the outer plate, and a second slide groove is provided at the lower end, and the first slide groove is communicated with the second slide groove to form a slide groove end; the electromagnetic valve assembly is connected to the sliding assembly through a syringe, and the sliding assembly is adapted to the slide groove end and can be axially slidably connected.

[0024] In an embodiment of the present application, the outer plate and the frame are connected by cylindrical pins, the syringe of the sliding assembly is connected to the solenoid valve assembly, the third solenoid valve is on the second solenoid valve, and the first solenoid valve is relative to the second solenoid valve and the third solenoid valve.

[0025] Based on the technical solutions provided above, in some possible implementations, the solenoid valve assembly includes a second solenoid valve and a first solenoid valve, the second solenoid valve is provided on one side of the outer plate, and an intersection plate is provided on the other side of the outer plate, the first solenoid valve is installed on one side of the intersection plate, and the intersection plate and the first solenoid valve are both provided above the motor.

[0026] In an embodiment of the present application, the photoelectric switch is located in the middle position of the side of the second plate close to the screw shaft, and the intersection block solenoid valve is placed vertically, and the single liquid circulation function can be directly realized through the back or side flow channel layout; one intersection block solenoid valve is placed in front and behind, which can realize the function of two liquids flowing alternately.

[0027] The second plate is provided with the second sliding groove for the axial movement of the sliding plate; the first sliding surface is matched with the second sliding surface on the inner side wall of the sliding groove end and is axially slidably connected.

[0028] Because some extensions can be added, through the integrated use of the intersection block and the solenoid valve assembly, the constant temperature liquid can circulate directly inside the intersection block, and the constant temperature of the liquid inside the syringe is guaranteed by directly switching the first solenoid valve and the third solenoid valve, which effectively reduces the static heat loss of the pipeline and improves the direct effect of temperature on chemical reactions.

[0029] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0030] The present invention discloses a quantitative liquid adding device and system. In addition to satisfying the radial limit sliding of axial movement, the sliding plate also takes into account the axial sliding of the syringe plunger pulling rod and the origin optical coupling triggering function. Compared with the conventional injection pump, all directional auxiliary structures such as linear guides are eliminated, and the material is less and the structure is simpler. The device and system can make the lead screw and the lead screw nut slide with no gap and high precision, and realize the minimum friction force, the lowest kinetic energy loss, and the highest instantaneous speed by gap matching, so as to maximize the low loss and high response characteristics of the stepping motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0032] Figure 1 It is a schematic diagram of the back structure provided by an embodiment of the present invention.

[0033] Figure 2 It is a schematic diagram of the front structure provided by an embodiment of the present invention.

[0034] Figure 3 It is a schematic diagram of the structure of the sliding plate of the injection pump provided in an embodiment of the present invention.

[0035] Figure 4 It is a schematic diagram of the structure of the lower support for a syringe provided in an embodiment of the present invention.

[0036] 1-motor, 2-first screw, 3-photoelectric switch, 4-sliding plate, 5-frame, 7-bearing pressure plate, 8-second screw, 9-outer plate, 10-intersection plate, 11-first solenoid valve, 12-waterproof plate, 13-second solenoid valve, 14-third solenoid valve, 15-syringe, 16-limiting plate, 17-locking pin, 19-cylindrical pin, 20-threaded assembly, 21-optical coupler trigger part, 22-first sliding surface, 23-positioning hole, 24-positioning hole boss, 25-motor boss mounting hole, 26-optical coupler mounting position, 27-second sliding surface, 28-bearing mounting hole, 29-first plate, 30-second plate, 31-third plate, 32-positioning plate. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0038] Example

[0039] See also Figure 1-4 As shown, an embodiment of the present application provides a quantitative liquid adding device, including a frame 5, on which a first sliding groove is provided for axial movement of a detachable sliding component, and the sliding component is connected to the motor 1 through a screw shaft; a nut assembly is provided in the inner sleeve of the sliding component, and the nut assembly includes a screw sleeve and a spline sleeve, and the screw sleeve and the spline sleeve are coaxially slidably connected and cooperate together on the screw shaft; a spring is provided on the outer wall of the screw sleeve, and a screw nut is provided at one end of the screw sleeve and a limit sleeve is provided at the other end, and the spring is used to support the screw nut and the limit sleeve.

[0040] Optionally, the sliding assembly includes a sliding plate 4, one end of which is detachably mounted on the lead screw nut, and the other end is slidably engaged with the first sliding groove; the sliding plate 4 is rotated to an externally driven stepping motor 1, the anti-backlash nut on the lead screw shaft is tightened, and the hexagon socket head screw is tightened on the side of the sliding plate 4.

[0041] Optionally, the sliding plate 4 has a threaded component 20 and a positioning plate 32 connected to the threaded component 20, the positioning plate 32 is slidably connected to the first slide groove, and the threaded component 20 is detachably sleeved on the screw shaft; the threaded component 20 is connected to the screw nut, and the inner hole on the threaded component 20 is sleeved on the screw shaft; the small contact surface of the slide groove will reduce the corresponding friction and ensure a certain strength.

[0042] Optionally, one end of the positioning plate 32 has a connecting portion, and the other end has an optocoupler trigger portion 21; the optocoupler trigger portion 21 is compatible with the photoelectric switch 3 provided on the frame 5; a sliding portion that can slide with the first slide groove is provided between the connecting portion and the optocoupler trigger portion 21; the connecting portion adopts a U-shaped body structure, and the U-shaped structure is provided with a corresponding positioning hole 23 and a positioning hole boss 24, and the other end is the optocoupler trigger portion 21. When it is separated from the photoelectric switch 3, the infrared device on the photoelectric switch 3 is triggered and it is in a moving state.

[0043] Optionally, the sliding portion has a first sliding surface 22, and both sides of the first sliding surface 22 have a clearance area, and the clearance area is a slope structure; the slope structure is a chamfer, and the slope prevents the syringe 15 from being abnormal, the slide plate is stuck to the aluminum alloy angle, and prevents abnormal surface contact from causing angle damage.

[0044] Optionally, the frame 5 includes a first plate 29, a second plate 30 and a third plate 31, and the second plate 30 is vertically connected between the first plate 29 and the third plate 31; a bearing pressure plate 7 is provided on the side of the third plate 31 away from the first plate 29, and the screw shaft passes through the thread in the sliding assembly on the bearing pressure plate 7, and the bearing pressure plate 7 is fastened to the third plate 31 by a second screw 8; the second plate 30 is vertically connected between the first plate 29 and the third plate 31, a bearing mounting hole 28 is provided on the first plate 29, and a motor boss mounting hole 25 is provided on the third plate 31, both of which can be used to install the mounting holes for the bearing setting.

[0045] Optionally, a waterproof plate 12 is provided above the motor 1 , and the waterproof plate 12 is perpendicular to the top surface of the motor 1 ; the waterproof plate 12 prevents water from falling and damaging the motor 1 .

[0046] Optionally, an optical coupler mounting position 26 is provided on the inner side wall of the second plate 30, and the optical coupler mounting position 26 fixes the photoelectric switch 3 to the side wall of the frame 5 through the first screw 2, and the photoelectric switch 3 is located below the motor 1; the origin optical coupler mounting position 26 is used to make the sliding plate 4, which is the trigger plate of the photoelectric switch 3, away from the arc surface of the sliding plate 4, which is more conducive to mechanical processing and production.

[0047] A quantitative liquid adding system includes an outer plate 9, a side of the outer plate 9 away from the screw shaft is tightly fitted with the other side of the frame 5; an electromagnetic valve assembly is provided at the upper end of the outer plate 9, and a second slide groove is provided at the lower end, and the first slide groove is communicated with the second slide groove to form a slide groove end; the electromagnetic valve assembly is connected to the sliding assembly through a syringe 15, and the sliding assembly is adapted to the slide groove end and can be axially slidably connected.

[0048] Optionally, the outer plate 9 and the frame 5 are connected by a cylindrical pin 19 , the syringe 15 of the sliding assembly is connected to the solenoid valve assembly, the third solenoid valve 14 is on the second solenoid valve 13 , and the first solenoid valve 11 is relative to the second solenoid valve 13 and the third solenoid valve 14 .

[0049] Optionally, the solenoid valve assembly includes a second solenoid valve 13 and a first solenoid valve 11, the second solenoid valve 13 is provided on one side of the outer plate 9, the intersection plate 10 is provided on the other side of the outer plate 9, the first solenoid valve 11 is installed on one side of the intersection plate 10, and the intersection plate 10 and the first solenoid valve 11 are both arranged above the motor 1; the photoelectric switch 3 is located in the middle position of the side of the second plate 30 close to the screw shaft, and the intersection block solenoid valve is placed vertically, and the single liquid circulation function can be directly realized through the back or side flow channel layout; one intersection block solenoid valve is placed in front and behind, which can realize the function of two liquids flowing alternately.

[0050] The second plate 30 is provided with a second sliding groove for the sliding plate 4 to move axially; the first sliding surface 22 is matched with the second sliding surface 27 on the inner side wall of the sliding groove end and is axially slidably connected.

[0051] It should be noted that in the prior art, there are three mechanical structures using the stepper motor 1 but with different transmission modes:

[0052] The first is that the stepper motor 1 drives the lead screw and lead screw nut through the coupling, and the pull rod support fixed on the end face of the lead screw nut pulls the injection rod to slide to achieve liquid transfer. The relatively complex structure has more parts. If the coupling is not well selected or the locking is not tight, there may be slippage, and absolute coaxiality cannot be guaranteed. In order to ensure the linear sliding of the lead screw nut, a linear slide is installed on one side of the lead screw for directional use, but due to tolerance factors, there is a radial offset and it is optimized to a double-sided linear slide. In addition, there is a gap between the lead screw and the lead screw nut due to material processing deformation or fitting tolerance, which causes fluctuations in the amount of liquid transferred.

[0053] The second step is to move the motor 1 to engage the synchronous belt teeth through the synchronous pulley, pull the pull rod support on the slider to drive the injection rod to slide to achieve liquid transfer. The tension of the pulley during assembly, the pulley jitter caused by the transmission inertia, and the pulley loosening caused by the aging of the pulley will cause the drift of the accuracy of the liquid addition and the fluctuation of stability. In order to solve the jitter of the belt inertia, a linear guide is installed near the pulley, but the guide slider is pre-tightened for debugging, and the individual resistance difference indirectly causes the motor 1 drive load to have a slight difference fluctuation, and the radial clearance of the slider itself causes the liquid volume fluctuation of the transfer liquid, which is larger than the fluctuation range of the screw motor 1.

[0054] The third step is that the stepper motor 1 is driven to the rack pull rod support through the gear group meshing and deceleration, and then pulls the injection rod to slide to achieve liquid transfer. Through the overlapping meshing of multiple small modulus gear groups, although the mechanical gap can be reasonably dispersed, the accuracy of liquid transfer can be effectively improved compared with belt transmission, but the structure is complex and the assembly and adjustment are difficult. It has high requirements for processing, production and debugging, and is bulky and has high production costs. All three structures have defects to varying degrees. However, if an inertial through-axis stepper motor 1 is used, the screw rod directly passes through the coil of the motor 1, and the screw rod rotates and moves. The screw rod rotates and pulls the pull rod support fixed at the top, pulling the injection rod to slide to achieve liquid transfer. Although the response time is relatively fast, the screw rod moves back and forth in the motor 1, occupying a large volume space. When the screw rod is loaded and transmitted to the farthest distance of the motor 1, the load force causes the screw rod to deform or bend due to axial force, causing the internal bearing of the motor 1 to be unevenly stressed and accelerate ball wear, affecting the life or gradually reducing the performance. The above structures are complex or have large friction or general accuracy, but they cannot fully meet the detection requirements of high response, high efficiency and high precision. In order to make the accuracy as accurate as possible, the current common practice is to drive the liquid to be sucked in by software, and then spit out the liquid slightly, and use the reverse action to eliminate the mechanical clearance between the screw nut and the screw rod to achieve higher accuracy and repeatability.

[0055] In summary, the present invention adopts a U-shaped frame 5 under the syringe 15 to minimize the processing process and time, reduce process energy loss and process equipment damage, and the special structural shape of the sliding plate 4 not only meets the radial limit sliding of the axial movement, but also takes into account the axial sliding of the plunger pull rod of the syringe 1515 and the origin optical coupling trigger function. Compared with conventional injection pumps, all directional auxiliary structures such as linear guides are eliminated, less materials are needed, and the structure is simpler.

[0056] It should be noted that the output characteristics of stepper motor 1 are: the greater the output torque, the lower the speed; the higher the speed, the smaller the output torque. The sliding plate 4 is made of engineering plastic with high-strength self-lubricating ability, and the side sliding force surface adopts a groove design. Under the premise of satisfying the radial shear force without damaging the strength of the sliding surface, the clearance fit is used to achieve the minimum friction, the lowest kinetic energy loss, and the highest instantaneous speed, which perfectly combines the characteristics of motor 1 and maximizes the low loss and high response characteristics of stepper motor 1.

[0057] Some extensions can be added. According to the statistics of actual test data, the 15-unit structure of the syringe has no software correction and the filling liquid deviation is ≤0.05mg, and the fastest single action cycle is <25ms. It is used with very few materials, and most parts have no dimensional accuracy requirements, which minimizes the assembly operation degree, and achieves the minimum batch difference and system error with a sophisticated motion structure and reasonable margin allocation.

[0058] The working principle of the quantitative liquid adding system is as follows: a flexible spring with a certain elastic force is used to axially support the screw nut and the limiting sleeve within the designed distance, and the axial side top force acting on the double screw nut is used to ensure that the double screw nut is reversely attached to the screw thread, and the axial reaction force between the double screw nut and the screw is used to achieve axial mechanical clearance-free; the double screw nut is radially limited by the keyway using the axial sliding radial positioning principle of the spline groove to ensure the radial synchronization of the double screw nut; the zero clearance fit between the screw and the screw nut is ensured by the axial clearance elimination and radial limitation of the screw nut. In use, under the axial spring reverse force, the anti-backlash nut makes radial rotational movement with the anti-backlash nut in the unchanged axial position. Because the sliding plate 4 is placed in the middle slide groove of the frame 5, the side blocking force of the slide groove is greater than the axial reverse force of the anti-backlash nut, so that the radial movement is converted into the axial movement of the anti-backlash nut and the screw of the sliding plate 4. During the axial movement of the sliding plate 4, the axial force is converted into radial shear force by external force, which will generate local pressure on the side of the frame 5. In order to ensure the strength of the slideway of the frame 5, aluminum alloy is selected as the frame design; in order to achieve high strength, maintenance-free, stable and reliable, the sliding plate 4 is made of engineering plastics with self-lubricating, weather-resistant and chemical-resistant properties. When the external drive stepper motor 1 rotates radially, the sliding plate 4 is driven to move axially in the frame 5 of the syringe 15, and the plunger pull rod fixed on the syringe 15 directly follows the axial movement of the sliding plate 4 to achieve the purpose of transferring liquid.

[0059] Example 2

[0060] This embodiment is based on the embodiment 1, the sliding plate 4 is the assembly position of the clearance nut, the sliding plate 4 is screwed into the clearance nut attached to the lead screw of the external drive stepper motor 1, and the hexagon socket head screw is tightened from the radial arc side after tightening. The sliding plate 4 is the trigger plate of the photoelectric switch 3, which is used to cooperate with the software to realize the home position control of the syringe 15 to prevent the syringe 15 from over-travel movement.

[0061] The sliding plate 4 is a radial positioning surface and an axial sliding surface, and is made of engineering plastic material with high strength self-lubricating ability. While maintaining strength, it also has good self-lubricating properties. The side sliding surface of the sliding plate 4 and the side sliding surface of the syringe 15 frame 5 are made of soft and hard materials for friction, to avoid the phenomenon of tumors and scratches caused by similar material hardness. At the same time, the sliding surface is further protected during the sliding process after foreign objects fall into the sliding surface in a normal or harsh environment to prevent damage to the sliding surface, resulting in changes in the accuracy of the injection liquid or jamming.

[0062] The side sliding surface of the sliding plate 4 has a 45° transition slope with the side surface, which guides the insertion of the syringe 15 into the slide groove of the frame 5 during the assembly process, ensuring that the sliding surface of the sliding plate 4 will not cause any surface damage or scratches during the process.

[0063] The upper and lower chamfers of the sliding surface of the sliding plate 4 are matched with the arcs at the four corners of the sliding surface of the frame 5 to prevent the sliding surface of the syringe 15 from being stuck in the arcs at the four corners of the sliding surface of the frame 5 after the over-travel movement, causing the sliding surface of the sliding plate 4 to be squeezed and deformed, resulting in sliding setbacks or affecting the sliding friction. At the same time, it is ensured that after the syringe 15 moves over the travel, the contact area between the chamfered part of the sliding plate 4 and the upper and lower non-slip surfaces of the injector frame 5 is too large, and the remaining gap is too small, resulting in the failure of the sliding plate 4 to drive the syringe 15 to return to the origin.

[0064] The through holes at the sliding plate 4 ensure that the syringe 15 withdrawal rod is subjected to balanced horizontal force, and the bosses at the sliding plate 4 ensure that the syringe pump locking pin 17 protects the syringe 15 withdrawal rod from being subjected to horizontal force and then generating a reverse force to tighten it through the threaded screws against the bosses.

[0065] The top of the sliding plate 4 is chamfered to prevent the top of the sliding plate 4 from sliding in the axial direction and causing crushing trauma to the maintenance personnel due to misoperation.

[0066] Example 3

[0067] This embodiment is based on Embodiments 1 and 2. The frame 5 is made of standard profiles as raw materials, and only 0.2 mm benchmark correction cutting is performed on the surface. The external drive stepper motor 1 body boss positioning hole 23 is provided.

[0068] The frame 5 is a micro-bearing assembly hole, and the boss at the bottom of the frame 5 is used to limit the micro-bearing, ensuring that the micro-bearing and the motor 1 lead screw are in absolute concentricity, ensuring that the lead screw will not be deformed or bent under force after the sliding plate 4 and the lead screw nut move away from the motor 1 body at full stroke, ensuring the tightness of the fit between the lead screw and the lead screw nut and the long life of the transmission.

[0069] Example 4

[0070] This embodiment is based on Embodiments 1, 2 and 3. The syringe 15 is a precision and fragile material, and its main body is made of glass. Any machined parts have certain mechanical deviations. After the system is assembled as a whole, in order to ensure the natural coaxiality of the withdrawal rod of the syringe 15 and the glass tube of the syringe 15, the U-shaped groove between the sliding plates 4 is slightly larger than the through hole of the withdrawal rod of the syringe 15, and the locking pin 17 is slightly smaller than the through hole of the withdrawal rod of the syringe 15. After the syringe 15 is assembled, the natural coaxiality of the withdrawal rod and the glass tube is automatically aligned, and then the withdrawal rod of the syringe 15 is locked by the injection pump push rod plate to ensure that there is no gap in the axial sliding.

[0071] It should be noted that the solenoid valve of the intersection block of the syringe 15 is placed vertically, and the single liquid circulation function can be realized directly through the back or side flow channel layout. The solenoid valve of the intersection block of the syringe 15 is placed one at the front and one at the back, which can realize the interactive flow function of two liquids.

[0072] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0073] In addition, the terms "parallel", "vertical", etc. do not mean that the components must be absolutely parallel or vertical, but can be slightly tilted. For example, "parallel" only means that its direction is more parallel than "vertical", and does not mean that the structure must be completely parallel, but can be slightly tilted.

[0074] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0075] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A quantitative liquid adding device, characterized in that: It comprises a frame (5), the frame (5) being provided with a first slide groove for axial movement of a detachable sliding assembly, the sliding assembly being connected to the motor (1) via a lead screw shaft; A nut assembly is sleeved inside the sliding assembly, and the nut assembly includes a lead screw sleeve and a spline sleeve, and the lead screw sleeve and the spline sleeve are coaxially slidably connected and cooperate with the lead screw shaft; A spring is provided on the outer wall of the lead screw sleeve, one end of the lead screw sleeve has a lead screw nut, one end of the lead screw sleeve has a limit sleeve, and the spring is used to support the lead screw nut and the limit sleeve to eliminate the axial clearance between the lead screw and the lead screw nut; The sliding assembly comprises a sliding plate (4), one end of the sliding plate (4) being detachably sleeved on the lead screw nut, and the other end of the sliding plate (4) being slidably engaged with the first sliding groove; The sliding plate comprises a threaded component (20) and a positioning plate (32) connected to the threaded component (20), the positioning plate (32) being slidably connected to the first sliding groove, and the threaded component (20) being detachably sleeved on the screw shaft; The threaded component (20) is connected to the lead screw nut, and the inner hole on the threaded component (20) is sleeved on the lead screw shaft; One end of the positioning plate (32) has a connecting portion, and the other end has an optical coupling trigger portion (21); The optical coupling trigger part (21) is compatible with the photoelectric switch (3) on the frame (5); A sliding portion is provided between the connecting portion and the optical coupling trigger portion (21) and is slidably matched with the first sliding groove; A waterproof plate (12) is provided above the motor (1), and the waterproof plate (12) is perpendicular to the top surface of the motor (1).

2. A quantitative liquid adding device according to claim 1, characterized in that: The sliding portion has a first sliding surface (22), and both sides of the first sliding surface (22) have a clearance area, and the clearance area is a slope structure.

3. A quantitative liquid adding device according to claim 2, characterized in that: The frame (5) comprises a first plate (29), a second plate (30) and a third plate (31), wherein the second plate (30) is vertically connected between the first plate (29) and the third plate (31); A bearing pressure plate (7) is provided on a side of the third plate (31) away from the first plate (29); the lead screw shaft passes through a thread in the sliding assembly and is attached to the bearing pressure plate (7); and the bearing pressure plate (7) is fastened to the third plate (31).

4. A quantitative liquid adding device according to claim 3, characterized in that: An optical coupler mounting position (26) is provided on the inner side wall of the second plate (30), and the photoelectric switch (3) is fixed to the optical coupler mounting position (26) by means of a first screw (2), and the photoelectric switch (3) is located below the motor (1).

5. A quantitative liquid adding system, characterized in that: It comprises an outer plate (9) and a quantitative liquid adding device as claimed in any one of claims 1 to 4 mounted on the outer plate (9), wherein a side surface of the outer plate (9) away from the screw shaft is tightly fitted with another side surface of the frame (5); The outer plate (9) has an electromagnetic valve assembly at its upper end and a second slide groove at its lower end, wherein the first slide groove communicates with the second slide groove to form a slide groove end; the electromagnetic valve assembly is connected to the sliding assembly via a syringe (15), and the sliding assembly is adapted to the slide groove end and is axially slidably connected thereto.

6. A quantitative liquid adding system according to claim 5, characterized in that: The solenoid valve assembly comprises a second solenoid valve (13) and a first solenoid valve (11); the second solenoid valve (13) is arranged on one side of the outer plate (9); and a junction plate (10) is arranged on the other side of the outer plate (9); the first solenoid valve (11) is installed on one side of the junction plate (10); and the junction plate (10) and the first solenoid valve (11) are both arranged above the motor (1).

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