Sample injection needle mechanism for automatic sample injector
By introducing photoelectric switch detection and guide rod limiting structure into the autosampler, the problem of difficult control of the sampling needle movement distance is solved, achieving precise control and stability of the sampling process and reducing production costs.
Patent Information
- Application Number
- CN202422906702.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2034-11-27
AI Technical Summary
In existing autosamplers, the movement distance of the sampling needle is difficult to control precisely during the sampling and injection process, which can easily puncture the sampling bottle and affect the smooth progress of the sampling process.
A sampling needle mechanism was designed, comprising a base, a slide, a drive mechanism, a position detection mechanism, and an empty bottle sensing mechanism. The position of the sampling needle is detected by a photoelectric switch to control its movement stroke, and a guide rod and a limiting plate are provided to ensure stability and precise movement.
It achieves precise position control of the sampling needle, avoids excessive movement of the sampling needle, ensures smooth sampling process, and has a simple structure and low production cost.
Smart Images
Figure CN223538838U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of analytical instrument technology, and more specifically, to a sample injection needle mechanism for an autosampler. Background Technology
[0002] In chromatographic analysis, the device that quantitatively delivers a sample into the chromatographic column is called an injector. Injectors are divided into two types: manual injectors and automatic injectors.
[0003] An autosampler is an intelligent and automated sampling instrument. Simply set the injection parameters and place the sample to be tested, and the automatic injection process is complete. During autosampler operation, the user must place the liquid sample vial on the sample tray beforehand. The autosampler then performs the sampling and injection actions according to control commands and signals. Both sampling and injection are accomplished by a sampling needle.
[0004] However, some existing injector designs make it inconvenient to control the extreme position of the sampling needle in the vertical direction. If the sampling needle moves too far during the sampling or injection process, it is easy to puncture the sampling bottle below the sampling needle, thus affecting the smooth progress of the entire sampling process.
[0005] Therefore, a needle mechanism for an autosampler is proposed. Utility Model Content
[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a sample injection needle mechanism for an autosampler.
[0007] The objective of this utility model is achieved through the following technical solution:
[0008] An injection needle mechanism for an autosampler includes a base, a slide and a drive mechanism both disposed on the base, the slide being slidably connected to the base and sliding in a direction parallel to the vertical direction; the drive mechanism being drively connected to the slide; a sampling needle and an empty bottle sensing mechanism are disposed on the slide, the central axis of the sampling needle being parallel to the vertical direction; and a position detection mechanism is also disposed on the slide.
[0009] Furthermore, in this utility model, the position detection mechanism includes a sensing plate disposed on one side of the slide and an upper photoelectric switch and a lower photoelectric switch disposed at intervals on one side of the base. The lower photoelectric switch is located directly below the upper photoelectric switch, and the sensing plate can be moved to the upper photoelectric switch or the lower photoelectric switch.
[0010] Furthermore, in this utility model, the empty bottle sensing mechanism includes a pressure rod slidably connected to the slide block, a first spring sleeved on the pressure rod, a bottle cap and an empty bottle sensing plate both disposed at the bottom end of the pressure rod, and an empty bottle photoelectric switch disposed on the base. The central axis of the pressure rod is parallel to the vertical direction; the top end of the first spring is connected to the slide block, and its bottom end is connected to the bottom end of the pressure rod; the empty bottle sensing plate is slidably connected to the empty bottle photoelectric switch.
[0011] Furthermore, in this utility model, a guide rod is slidably connected to the slide block, and the central axis of the guide rod is parallel to the vertical direction; the top end of the guide rod is connected to the top end of the pressure rod through a connecting piece.
[0012] Furthermore, in this utility model, a second spring is sleeved on the guide rod, the top end of the second spring is connected to the slide block, and its bottom end is connected to the bottom end of the guide rod.
[0013] Furthermore, in this utility model, a guide shaft is provided on the base, the central axis of the guide shaft is parallel to the vertical direction, and the slide is slidably connected to the guide shaft; the driving mechanism includes a lead screw rotatably connected to the base, the central axis of the lead screw is parallel to the vertical direction; the slide is threadedly connected to the lead screw.
[0014] Furthermore, in this utility model, a limiting plate is provided at the bottom of the base, and the sampling needle passes through the limiting plate.
[0015] The beneficial effects of this utility model are:
[0016] 1. By installing a position detection device on the base, when the sensing element moves to the upper photoelectric switch, the upper photoelectric switch senses the presence of the sensing element. This signal value is transmitted to the corresponding control system, which controls the drive mechanism to stop the slide from moving upward, and the sampling needle also stops moving upward. Conversely, when the sensing element moves to the lower photoelectric switch, the lower photoelectric switch senses the presence of the sensing element. This signal value is transmitted to the corresponding control system, which controls the drive mechanism to stop the slide from moving downward, and the sampling needle also stops moving downward. This is to control the movement stroke of the sampling needle and avoid excessive movement.
[0017] 2. The injection needle mechanism has a compact and simple structure, resulting in low production costs. Attached Figure Description
[0018] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model.
[0019] In the diagram: 101-Base; 201-Slide; 301-Sampling needle; 401-Sensing plate; 402-Upper photoelectric switch; 403-Lower photoelectric switch; 501-Pressure rod; 502-First spring; 503-Bottle cap press; 504-Empty bottle sensing plate; 505-Empty bottle photoelectric switch; 601-Guide rod; 602-Connecting piece; 701-Second spring; 801-Guide shaft; 901-Lead screw; 1001-Limiting plate. Detailed Implementation
[0020] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0021] Please see Figure 1 This utility model provides a technical solution:
[0022] A sample injection needle mechanism for an autosampler includes a base 101, a slide 201 mounted on the base 101, and a drive mechanism. The slide 201 is slidably connected to the base 101, and its sliding direction is parallel to the vertical direction. The drive mechanism is driven by the slide 201 and is used to drive the slide 201 to reciprocate in the vertical direction. A sampling needle 301 for extracting samples and an empty bottle sensing mechanism for detecting whether there is a sample bottle below the sampling needle 301 are mounted on the slide 201. The central axis of the sampling needle 301 is parallel to the vertical direction.
[0023] When the drive mechanism drives the slide 201 to move up and down in the vertical direction, the sampling needle 301 also moves up and down synchronously with the slide 201. To facilitate control of the movement stroke of the sampling needle 301, a position detection mechanism is installed on the slide 201. Specifically, in this embodiment, the position detection mechanism includes a sensing plate 401 installed on one side of the slide 201 and an upper photoelectric switch 402 and a lower photoelectric switch 403 installed at intervals on one side of the base 101. The lower photoelectric switch 403 is located directly below the upper photoelectric switch 402. Both the upper photoelectric switch 402 and the lower photoelectric switch 403 are electrically connected to the drive mechanism. In this way, the sensing plate 401 will move synchronously with the slide 201. A photoelectric switch is short for photoelectric proximity switch. It uses the blocking or reflection of a light beam by the object being detected to connect the circuit through a synchronous circuit, thereby detecting the presence or absence of the object. The object is not limited to metal; all objects that can reflect light (or block light) can be detected. When the sensing element 401 moves to the upper photoelectric switch 402, the upper photoelectric switch 402 senses the presence of the sensing element 401, and this signal value is transmitted to the corresponding control system. The control system controls the drive mechanism to stop the slide 201 from moving upward. Conversely, when the sensing element 401 moves to the lower photoelectric switch 403, the lower photoelectric switch 403 senses the presence of the sensing element 401, and this signal value is transmitted to the corresponding control system. The control system controls the drive mechanism to stop the slide 201 from moving downward.
[0024] In this embodiment, the empty bottle sensing mechanism includes a pressure rod 501 slidably connected to the slide 201, a first spring 502 sleeved on the pressure rod 501, a bottle cap 503 and an empty bottle sensing plate 504 both mounted on the bottom end of the pressure rod 501, and an empty bottle photoelectric switch 505 mounted on the base 101. The central axis of the pressure rod 501 is parallel to the vertical direction. The top end of the first spring 502 is connected to the slide 201, and its bottom end is connected to the bottom end of the pressure rod 501. The empty bottle sensing plate 504 is slidably connected to the empty bottle photoelectric switch 505. As the sampling needle 301 moves downward, the pressure rod 501 moves downward synchronously. When there is no sample bottle below the sampling needle 301, the bottle cap 503 moves downward without resistance, and the empty bottle sensor 504 separates from the empty bottle photoelectric switch 505. When there is a sample bottle below the sampling needle 301, as the bottle cap 503 moves downward and encounters the sample bottle, the first spring 502 on the pressure rod 501 is compressed under the resistance of the sample bottle. During this process, the pressure rod 501 moves upward, and the empty bottle sensor 504 remains within the empty bottle photoelectric switch 505. After the empty bottle sensor 504 separates from the empty bottle photoelectric switch 505, the light beam of the empty bottle photoelectric switch 505 cannot be blocked by the empty bottle sensor 504, thus detecting that there is no sample bottle below the sampling needle 301. After the sampling needle 301 extends into the sample bottle to extract the sample, the drive mechanism controls the lead screw 901 to rotate, causing the slide 201 to move upward, and the sampling needle 301 is then extracted from the sample bottle. The tip of the sampling needle 301 is connected to a PEEK two-way tubing connector, which facilitates the connection of the tip of the sampling needle 301 to the tubing.
[0025] In order to prevent the pressure rod 501 from rotating during the up and down movement of the pressure rod 501, a guide rod 601 is slidably connected on the slide block 201 in this embodiment. The central axis of the guide rod 601 is parallel to the vertical direction. The top end of the guide rod 601 is connected to the top end of the pressure rod 501 through a connecting piece 602.
[0026] To increase the stability of the above structure, a second spring 701 is sleeved on the guide rod 601. The top end of the second spring 701 is connected to the slide block 201, and its bottom end is connected to the bottom end of the guide rod 601.
[0027] To facilitate the drive mechanism's control of the slide 201's vertical movement on the base 101, a guide shaft 801 is mounted on the base 101. The central axis of the guide shaft 801 is parallel to the vertical direction, and the slide 201 is slidably connected to the guide shaft 801. The drive mechanism includes a lead screw 901 rotatably connected to the base 101, with its central axis parallel to the vertical direction. The slide 201 is threadedly connected to the lead screw 901. Thus, the lead screw 901, slide 201, and guide shaft 801 form a common lead screw 901 nut mechanism. In this embodiment, the forward and reverse rotation of the lead screw 901 is controlled by a synchronous belt mechanism.
[0028] In this embodiment, a limiting plate 1001 is installed at the bottom of the base 101, and the sampling needle 301 passes through the limiting plate 1001. The limiting plate 1001 limits the sampling needle 301, so that the sampling needle 301 will not deviate when it moves up and down in a straight line.
[0029] The above description is merely a preferred embodiment of this utility model. It should be understood that this utility model is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this utility model should be protected within the scope of the appended claims.
Claims
1. A syringe injection mechanism for an autosampler, characterized in that: The device includes a base (101), a slide (201) and a driving mechanism, both mounted on the base (101). The slide (201) is slidably connected to the base (101), and its sliding direction is parallel to the vertical direction. The driving mechanism is connected to the slide (201) in a transmission manner. The slide (201) is provided with a sampling needle (301) and an empty bottle sensing mechanism, and the central axis of the sampling needle (301) is parallel to the vertical direction. The slide (201) is also provided with a position detection mechanism. The position detection mechanism includes a sensing plate (401) disposed on one side of the slide (201) and an upper photoelectric switch (402) and a lower photoelectric switch (403) spaced apart on one side of the base (101). The lower photoelectric switch (403) is located directly below the upper photoelectric switch (402). The sensing plate (401) can be moved to the upper photoelectric switch (402) or the lower photoelectric switch (403). Both the upper photoelectric switch (402) and the lower photoelectric switch (403) are electrically connected to the drive mechanism.
2. The injection needle mechanism for an autosampler according to claim 1, characterized in that: The empty bottle sensing mechanism includes a pressure rod (501) slidably connected to the slide (201), a first spring (502) sleeved on the pressure rod (501), a bottle cap (503) and an empty bottle sensing plate (504) both disposed at the bottom end of the pressure rod (501), and an empty bottle photoelectric switch (505) disposed on the base (101). The central axis of the pressure rod (501) is parallel to the vertical direction; the top end of the first spring (502) is connected to the slide (201), and its bottom end is connected to the bottom end of the pressure rod (501); the empty bottle sensing plate (504) is slidably connected to the empty bottle photoelectric switch (505).
3. The injection needle mechanism for an autosampler according to claim 2, characterized in that: A guide rod (601) is slidably connected to the slide (201), and the central axis of the guide rod (601) is parallel to the vertical direction; the top end of the guide rod (601) is connected to the top end of the pressure rod (501) through a connecting piece (602).
4. The injection needle mechanism for an autosampler according to claim 3, characterized in that: A second spring (701) is sleeved on the guide rod (601). The top end of the second spring (701) is connected to the slide (201), and its bottom end is connected to the bottom end of the guide rod (601).
5. The injection needle mechanism for an autosampler according to claim 1, characterized in that: The base (101) is provided with a guide shaft (801), the central axis of the guide shaft (801) is parallel to the vertical direction, and the slide (201) is slidably connected to the guide shaft (801); the driving mechanism includes a lead screw (901) rotatably connected to the base (101), the central axis of the lead screw (901) is parallel to the vertical direction; the slide (201) is threadedly connected to the lead screw (901).
6. The injection needle mechanism for an autosampler according to claim 1, characterized in that: The base (101) is provided with a limiting plate (1001) at its bottom, and the sampling needle (301) passes through the limiting plate (1001).