CN210953939U

CN210953939U - Sample injector

Info

Publication number: CN210953939U
Application number: CN201921915164.1U
Authority: CN
Inventors: 魏伟; 石地娟; 高艳华; 王钦玥
Original assignee: Lanzhou Donglilong Information Technology Co ltd
Current assignee: Lanzhou Donglilong Information Technology Co ltd
Priority date: 2019-11-05
Filing date: 2019-11-05
Publication date: 2020-07-07
Anticipated expiration: 2029-11-05

Abstract

The utility model discloses a sample injector, which comprises a cylinder body, a push rod and a push head; the first end of the positioning component is fixedly connected to the position of the push rod close to the push head, and the second end of the positioning component is movably connected to the outer wall of the cylinder body; moreover, the push rod slides up and down in the cylinder body, so that the second end of the positioning component slides up and down outside the cylinder body; the second end is provided with a locking member, when the locking member is in a locking state, the position of the second end relative to the outer wall of the barrel body is locked, and the relative position of the push rod in the barrel body is fixed. The utility model provides a sample injector, simple structure can guarantee sample volume stability after the sample, is difficult for changing to make the sample volume accurate.

Description

Sample injector

Technical Field

The utility model relates to a detection area, in particular to sample injector.

Background

When the chromatographic analysis is carried out, a sample needs to be injected into an analysis instrument for quantitative analysis through a sample injector, and whether the sample injection of the sample injector is accurate has important significance on the analysis result. Most of the currently commonly used sample injectors are ordinary syringes, and during sampling, an operator needs to carefully observe scales to determine the sampling amount. In addition, in the process of transferring the sample to the sample inlet of the chromatograph after sampling, the position of the piston in the sample injector may change due to operation and other reasons, so that the sampling amount is inaccurate, and the accuracy of test data is affected.

Chinese patent CN203337622U discloses an oil chromatography standard injector, set up the fixed bolster on the syringe, the fixed bolster includes the fixed plate, the control panel, two screw rods and fixation nut of upper baffle and the above-mentioned three board of connection, the fixed plate is fixed on the syringe section of thick bamboo, the top of syringe push rod is provided with upper baffle, upper baffle and fixed plate are connected through two screw rods, be provided with upper baffle nut on upper baffle upper portion, upper baffle ensures that the syringe push rod can not be released because of inlet pressure. A control plate is arranged between the upper baffle and the fixed plate, penetrates through the screw rod and is adjusted in position and positioned through a control plate nut arranged on the lower portion of the control plate, and therefore accuracy of gas production and gas inflow is guaranteed. The utility model discloses a set up the fixed bolster and realize the auxiliary sampling, make the sample volume with accurate, the syringe push rod position is more firm after the sample. But the device sets up complicacy, and application range is little, and only application scope gas sampling adjusts inconveniently, and the fixed plate is difficult for dismantling.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the problem that the prior art lacks simple structure and makes the stable sample injector of volume in the sampling container after the sample. The utility model provides a sample injector, simple structure can guarantee sample volume stability after the sample, is difficult for changing to make the sample volume accurate.

In order to solve the technical problem, an embodiment of the present invention discloses a sample injector, include: the device comprises a cylinder body, a push rod arranged in the cylinder body and a push head arranged at one end of the push rod and positioned outside the cylinder body; the first end of the positioning component is fixedly connected to the position of the push rod close to the push head, and the second end of the positioning component is movably connected to the outer wall of the cylinder body; moreover, the push rod slides up and down in the cylinder body, so that the second end of the positioning component slides up and down outside the cylinder body; the second end is provided with a locking member, when the locking member is in a locking state, the position of the second end relative to the outer wall of the barrel body is locked, and the relative position of the push rod in the barrel body is fixed.

By adopting the scheme, the positioning component is connected with the push rod and the barrel outside the barrel, the part of the positioning component connected with the barrel moves upwards or downwards on the outer wall of the barrel along with the movement of the push rod, the track is consistent with that of the push rod, and the position of the piston rod in the barrel is conveniently positioned. The positioning part is also provided with a locking member which can lock the position of the positioning part relative to the outer wall of the barrel body, so that the relative position of the push rod in the barrel body is fixed, the volume stability of a sample after sampling is ensured, and the sampling amount is accurate.

According to another embodiment of the present invention, an embodiment of the present invention discloses a sample injector, wherein the first end of the positioning member is detachably fixed to the pushing rod.

By adopting the scheme, the push rod can be separated from the cylinder body after being detached from the positioning component, so that the sample injector can be detached, maintained and cleaned conveniently after being used; and the positioning component can be installed or not installed according to the needs, so that the sample injector is convenient to use.

According to another embodiment of the present invention, an embodiment of the present invention discloses a sample injector, wherein the positioning member comprises a cylindrical body parallel to the extending direction of the push rod; the positioning member includes a first portion connected to the first end and a second portion connected to the second end; the first portion and the second portion are connected.

By adopting the scheme, the positioning component comprises the columnar body parallel to the extending direction, and is practical and simple in structure.

According to another embodiment of the present invention, an embodiment of the present invention discloses a sample injector, wherein the first portion and the second portion are detachably connected.

By adopting the scheme, the positioning component is convenient to disassemble into two separated parts, and is convenient to carry and package; and the positioning component is easily separated from the cylinder body.

According to another embodiment of the present invention, an embodiment of the present invention discloses a sample injector, wherein a first portion and a second portion are rotatably connected; the connecting part of the first part and the second part is also provided with a fixing component which fixes the connecting state of the first part and the second part.

By adopting the scheme, the positioning part is convenient to stabilize the structure by the fixing component when being connected to the push rod and the barrel body. When the first end of the positioning component is detached and separated from the pushing head, the fixing component is moved, the locking state is cancelled, and the first part is rotated, so that the second end of the positioning component is easily separated from the cylinder body.

According to another embodiment of the present invention, an embodiment of the present invention discloses a sample injector, wherein the second end of the positioning member comprises a ring which is matched with the cylinder and is sleeved on the outer wall of the cylinder; one side of the ring is provided with an opening; the locking member adjusts the distance between the two ends of the opening to a minimum and the locking ring positions relative to the outer wall of the barrel.

By adopting the scheme, when the push rod movably absorbs a quantitative sample in the barrel, the locking component fixes the position of the second end of the positioning part and fixes the position of the push rod, so that the position of the push rod relative to the barrel is stable, and the push rod does not move up or down due to internal or external pressure of the barrel, thereby stabilizing the sampling amount.

According to another embodiment of the present invention, an embodiment of the present invention discloses a sample injector, wherein two ends of the opening are respectively provided with a connecting member protruding from the ring; the locking member is disposed on the connecting member.

By adopting the scheme, the locking member is simple in structure and easy to operate.

According to the utility model discloses a further embodiment, the utility model discloses an embodiment discloses a sample injector, and locking member includes, set up in the ring periphery and with ring rotatable coupling's regulating ring, set up between ring and regulating ring and be close to the open-ended pressing shaft, and the position that is connected with the pressing shaft in the regulating ring sets up the recess that matches with the pressing shaft, and the smooth transition of groove depth diminishes gradually.

By adopting the scheme, the locking member is locked by rotating operation and is easy to operate.

According to the utility model discloses a further embodiment, the utility model discloses an embodiment discloses a sample injector, is provided with the scale on the barrel, and the position that the second end of locating part corresponds the scale is provided with scale indication component.

By adopting the scheme, the scale indicating component indicates the corresponding scale of the position of the push rod in the cylinder body, so that the sampler can sample more accurately.

According to another embodiment of the present invention, an embodiment of the present invention discloses a sample injector, wherein the scale indicating member comprises a scale magnifier.

By adopting the scheme, the magnifying glass magnifies the scales, so that the positions of the scales can be seen clearly in the sampling process, and the operation is convenient.

Drawings

FIG. 1 is a schematic diagram of an embodiment of a sample injector according to the present invention;

FIG. 2 is a schematic structural view of an embodiment of the sample injector of the present invention with a scale indicating member and a fixing member;

fig. 3 is an enlarged view of node a in fig. 2 according to the present invention.

Reference numerals:

1. a barrel; 2. a push rod; 3. a pusher head; 4. a positioning member; 41. a first end; 42. a second end; 421. a scale indicating member; 422. a locking member; 43. a first portion; 44. a second portion; 45. a fixing member.

Detailed Description

The following description is provided for illustrative embodiments of the present invention, and other advantages and effects of the present invention will be readily apparent to those skilled in the art from the disclosure herein. While the invention will be described in conjunction with the preferred embodiments, it is not intended that features of the invention be limited to only those embodiments. On the contrary, the intention of implementing the novel features described in connection with the embodiments is to cover other alternatives or modifications which may be extended based on the claims of the present invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The invention may be practiced without these particulars. Furthermore, some of the specific details are omitted from the description so as not to obscure or obscure the present invention. It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.

It should be noted that in this specification, like reference numerals and letters refer to like items in the following drawings, and thus, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

In the description of the present embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the present invention are usually placed in when used, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or the element to which the present invention is directed must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention.

The terms "first," "second," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

In the description of the present embodiment, it should be further noted that, unless explicitly stated or limited otherwise, the terms "disposed," "connected," and "connected" are to be interpreted broadly, e.g., as a fixed connection, a detachable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present embodiment can be understood in specific cases by those of ordinary skill in the art.

In order to make the objects, technical solutions and advantages of the present invention clearer, embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

In order to solve the above technical problem, an embodiment of the present invention discloses a sample injector, as shown in fig. 1 and fig. 2, including: the device comprises a cylinder body 1, a push rod 2 arranged in the cylinder body 1, and a push head 3 arranged at one end of the push rod 2 and positioned outside the cylinder body 1; the first end 41 of the positioning component 4 is fixedly connected to the position of the push rod 2 close to the push head 3, and the second end 42 is movably connected to the outer wall of the cylinder 1; moreover, the push rod 2 slides up and down in the cylinder 1, and the second end 42 of the positioning component 4 slides up and down outside the cylinder 1; the second end 42 is provided with a locking member 422, when the locking member 422 is in a locking state, the position of the second end 42 relative to the outer wall of the cylinder body 1 is locked, and the relative position of the push rod 2 in the cylinder body 1 is fixed.

Specifically, a kind of sample injector relies on the action of catch bar 2 piston in barrel 1, inhales the sample in barrel 1 or with the sample release in the barrel 1, catch bar 2 one end connection push head 3, rely on holding push head 3 and transmit external force and make catch bar 2 move about in barrel 1 during convenient operation, the general cross-section of push head 3 is greater than catch bar 2 cross-section, and can not get into in the barrel 1. The first end 41 of the positioning component 4 is fixedly connected to the position of the push rod 2 close to the push head 3, namely close to the outer wall of the end part of the push rod 2 which does not enter the cylinder 1; the first end 41 of the positioning component 4 can be directly connected with a certain position of the outer wall of the push rod 2, can be connected in a mode of inserting into the push rod 2, and can also be provided with a ring matched with the push rod 2 and sleeved on the push rod 2; the fixed connection mode can be non-detachable fixed connection such as welding, bonding and the like, and can also be detachable connection modes such as threads, riveting and the like. The second end 42 of the positioning component 4 is movably connected to the outer wall of the cylinder body 1, the relative position of the second end 42 and the outer wall of the cylinder body 1 is changeable, namely when the push rod 2 slides upwards or downwards in the cylinder body 1, the positioning component 4 is driven to move upwards or downwards by virtue of the fixed connection with the first end 41 of the positioning component 4, so that the second end 42 of the positioning component 4 moves upwards or downwards on the outer wall of the cylinder body 1; the moving track of the positioning component 4 is consistent with that of the push rod 2, so that the position of the piston rod in the cylinder body 1 is conveniently positioned.

The second end 42 of the positioning part 4 is further provided with a locking member 422 which can lock the position of the second end 42 relative to the outer wall of the cylinder 1, thereby fixing the relative position of the push rod 2 in the cylinder 1. Specifically, the second end 42 of the positioning component 4 may be a ring with a shape matching with the barrel 1 and sleeved on the barrel 1, a certain gap is left between the ring and the barrel 1 for facilitating sliding, a locking member 422, such as a bolt, is disposed on the ring, and the gap is adjusted and reduced to enable the ring to be tightly connected with the barrel 1, so as to limit sliding. The second end 42 of the positioning member 4 may also be provided with a sliding structure, such as a pulley, which is matched with the outer wall of the cylinder 1, and a locking member 422, such as a structure for limiting the sliding of the pulley, is provided thereon, and the sliding structure is locked by means of the locking member 422.

By adopting the scheme, the positioning component 4 is connected with the pushing rod 2 and the barrel body 1 outside the barrel body 1, the part of the positioning component 4 connected with the barrel body 1 moves upwards or downwards on the outer wall of the barrel body 1 along with the movement of the pushing rod 2, the track is consistent with that of the pushing rod 2, and the position of the piston rod in the barrel body 1 is conveniently positioned. The positioning part 4 is also provided with a locking member 422 which can lock the position of the positioning part 4 relative to the outer wall of the cylinder body 1, so that the relative position of the push rod 2 in the cylinder body 1 is fixed, the volume of a sample after sampling is ensured to be stable, and the sampling amount is accurate.

According to another embodiment of the present invention, the first end 41 of the positioning member 4 is detachably and fixedly connected to the pushing rod 2. Specifically, the first end 41 of the positioning part 4 connected with the push rod 2 is detachably connected with the push rod 2; for example, the pushing rod 2 can be provided with a component which is matched and connected with the positioning part 4, and the component is connected with the pushing rod 2 by riveting; the push rod 2 can be radially provided with an inner hole matched with the first end 41 of the positioning component 4, and the first end 41 of the positioning component 4 is inserted into the inner hole and fixed by means of threads or riveting; the first end 41 of the positioning part 4 can also be configured to include a ring that mates with the push rod 2 and is fixedly connected to the push rod 2 by means of a screw thread or a snap-fit.

By adopting the scheme, the push rod 2 and the positioning component 4 can be separated from the cylinder body 1 after being disassembled, so that the disassembly, maintenance and cleaning of the sample injector are convenient after the sample injector is used; and the positioning component 4 can be installed or not installed according to the needs, so that the sample injector is convenient to use.

According to another embodiment of the present invention, as shown in fig. 1 and 2, the positioning member 4 includes a cylindrical body parallel to the extending direction of the push rod 2. Specifically, the two ends of the positioning component 4 may depend on a straight circular arc, a cylinder 1 or a column, or other non-straight shapes, as long as the positioning component 4 and the push rod 2 can move in the same track, and the second end 42 of the positioning component 4 can move up and down freely on the outer wall of the cylinder. The embodiment selects the columnar body parallel to the extending direction of the push rod 2, and has practicality and simple structure.

It should be noted that the cylindrical body may be disposed close to the outer wall of the cylinder 1; the cylindrical body and the two ends of the positioning part 4 can be integrally formed or can be provided with a connecting structure. Usually, the inner diameter of the outer wall of the cylinder 1 is larger than the inner diameter of the push rod 2, and in order to realize that the cylindrical body is parallel to the push rod 2, the first end 41 of the positioning part 4 connected with the push rod 2 can also be provided with a section of structure which is perpendicular to the cylindrical body and is connected with the cylindrical body.

According to another embodiment of the present invention, as shown in fig. 2, the positioning member 4 comprises a first portion 44 connected to the first end 41, a second portion 45 connected to the second end 42; the first portion 44 and the second portion 45 are removably and fixedly connected. Specifically, two ends of the positioning component 4 are detachably and fixedly connected by threads, rivets, or the like, and the connection portion may be disposed on the cylindrical body or at one end of the cylindrical body, which is not specifically limited in this embodiment.

By adopting the scheme, the positioning component 4 is convenient to disassemble into two separated parts, and is convenient to carry and package. In particular, the end of the barrel 1 close to the pushing head 3 is usually disposed to protrude from the outer wall of the barrel 1, so that the second end 42 of the positioning member 4 can only be pushed out from the side of the barrel 1 far from the pushing head 3 to separate from the barrel 1. However, when the positioning member 4 is fixedly connected to the pushing head 3 after the first end 41 of the positioning member 4 is detached from the pushing head 3, the first end 41 of the positioning member 4 is smaller, so that the second end 42 is prevented from being detached from the cylinder 1. The positioning component 4 is arranged into two parts which are detachably connected, the problems can be solved, and the positioning component 4 is easily separated from the cylinder body 1.

According to another embodiment of the present invention, as shown in fig. 2, the positioning member 4 comprises a first portion 44 connected to the first end 41, a second portion 45 connected to the second end 42; the first portion 44 and the second portion 45 are rotatably connected; the connecting portion of the first portion 44 and the second portion 45 is further provided with a fixing member 46, and the fixing member 46 fixes the connected state of the first portion 44 and the second portion 45.

Specifically, the first portion 44 and the second portion 45 are rotatably connected by means of bolts, hinges, and the like, so that the position of the connection between the first portion 44 and the second portion 45 can be changed. For example, when the first end 41 of the positioning member 4 is connected to the pushing rod 2 and the second end 42 is connected to the barrel 1, the first end 41 and the second end 42 are parallel and extend in the same direction, and the column is parallel to the pushing rod 2. When the first end 41 of the positioning component 4 is detached from the push rod 2, the connection between the first part 44 and the second part 45 is rotated, and if the connection part is arranged at one end of the columnar body, the first end 41 and the second end 42 can be parallel but have different extending directions; or the attachment portion, if provided in the middle of the column, may allow the column to bend with the first portion 44 away from the push rod 2.

It should be noted that the connection state of the present invention specifically means a state in which the first end 41 of the positioning member 4 is connected to the push rod 2, the second end 42 is connected to the cylinder 1, and the cylindrical body is parallel to the push rod 2. The securing member 46 may be a sleeve, a slider, or the like that is movably connected to the column; it may be a friction locking arrangement at the connection between the first part 44 and the second part 45 in the connected state.

With the above-mentioned solution, the positioning component 4 is convenient to stabilize the structure by means of the fixing member 46 when being connected to the push rod 2 and the cylinder 1. When the first end 41 of the positioning component 4 is detached from the pushing head 3, the fixing member 46 is moved to cancel the locking state, and the first portion 44 is rotated, so that the second end 42 of the positioning component 4 can be easily detached from the barrel 1.

According to another embodiment of the present invention, as shown in fig. 2, the second end 42 of the positioning component 4 comprises a ring matching with the cylinder 1 and sleeved on the outer wall of the cylinder 1; one side of the ring is provided with an opening; the locking member 422 adjusts the distance across the opening to a minimum, locking the position of the ring relative to the outer wall of the barrel 1. Specifically, the second end 42 is provided with a ring matched with the cylinder 1, the ring is sleeved on the outer wall of the cylinder 1, a gap is left between the ring and the cylinder 1 or the connecting part is smooth, so that the ring can slide up and down along the outer wall of the cylinder 1; one side of the ring is provided with an opening, the tightness of connection between the distance adjusting ring at two ends of the opening and the cylinder body 1 can be adjusted by means of the locking component 422, when the distance between two ends of the opening is the minimum, the connection between the ring and the cylinder body 1 is the closest, the friction force is the maximum, and the position of the ring is locked relative to the outer wall of the cylinder body 1 by means of the friction force. The locking member 422 may be provided on the opening or may be provided on the entire ring, as long as it can adjust and lock the opening state.

By adopting the scheme, after the push rod 2 movably absorbs a certain amount of samples in the cylinder body 1 and is positioned to a certain amount of positions, the locking member 422 fixes the position of the second end 42 of the positioning part 4, and fixes the position of the push rod 2 by means of the fixed connection of the positioning part 4 and the push rod 2, so that the position of the push rod 2 relative to the cylinder body 1 is stable, and the push rod 2 does not move up or down due to the internal or external pressure of the cylinder body 1, thereby stabilizing the sampling amount.

According to another embodiment of the present invention, the two ends of the opening are respectively provided with a connecting member protruding from the ring; the locking member 422 is disposed on the connecting member. Specifically, the locking member 422 may be an adjusting bolt, a buckle, or the like, and a hole or a notch for placing the locking member 422 is provided on the connecting member; the locking member 422 is adjusted to reduce or enlarge the distance between the two sections of the connecting member, so that the distance of the opening is reduced or enlarged, and the connection between the locking ring and the outer wall of the barrel body is locked or loosened.

By adopting the scheme, the locking member 422 is simple in structure and easy to operate.

According to the utility model discloses a further embodiment, locking member 422 includes, set up in the ring periphery and with ring rotatable coupling's regulating ring, set up between ring and regulating ring and be close to the open-ended pressing shaft, set up the recess that matches with the pressing shaft with the position setting that compresses tightly the hub connection in the regulating ring, the recess degree of depth smooth transition diminishes gradually (the drawing is not shown).

Specifically, the periphery of the ring is provided with an adjusting ring matched with the ring, and the adjusting ring can rotate around the ring in all directions or at a certain angle; the connection between the adjusting ring and the ring may be detachable or not, which is not limited in this embodiment. A pressing shaft is arranged between the ring and the adjusting ring and close to the opening, the axial direction of the pressing shaft is consistent with the axial direction of the ring, and the length of the pressing shaft is matched with that of the ring.

It should be noted that the pressing shaft can be arranged close to one of the openings or two of the openings respectively, a groove matched with the pressing shaft is arranged in the position connected with the pressing shaft in the adjusting ring, and the depth of the groove is gradually reduced in a smooth transition manner; the position of the groove with the minimum size can be provided with a stop block or a friction force increasing structure, so that the pressing shaft is stable when being positioned at the position with the minimum size for early operation and cannot automatically slide to the maximum size. The adjusting ring can rotate around an angle formed by an arc extending from the ring in the groove, when the adjusting ring rotates to the deepest position of the groove of the pressing shaft, the opening of the ring is the largest, and the ring is loosely connected with the outer wall of the cylinder body 1 and can slide up and down; when the adjusting ring rotates to the position where the pressing shaft is at the shallowest position of the groove, the opening of the ring is the smallest, the ring is tightly connected with the outer wall of the cylinder body 1, the ring can not slide up and down due to friction force, and the relative position of the locking ring and the cylinder body 1 is locked.

The pressing shafts can also be arranged to be evenly distributed on three or more than three of the periphery of the ring; a groove matched with the pressing shaft is arranged at the position connected with the pressing shaft in the adjusting ring, the depth of the groove is smoothly transited and gradually reduced, and the adjusting ring can rotate around the angle formed by the arc of the ring extending in the groove; also can set up between the recess shallowest department and deepest interconnect according to the compact axle quantity, adjust the circle and encircle ring periphery omnidirectional rotation.

By adopting the scheme, the locking component 422 is locked by rotation operation and is easy to operate.

According to another embodiment of the present invention, as shown in fig. 2-3, the cylinder 1 is provided with a scale, and the second end 42 of the positioning component 4 is provided with a scale indicating member 421 corresponding to the scale. Specifically, the second end 42 of the positioning part 4 is provided with a scale indication member 421 for indicating the position of the push rod 2 in the barrel 1 to correspond to the scale, the scale indication member 421 can be arranged as a frame or a rod close to the scale of the barrel 1 without covering the scale, and as shown in fig. 3, a mark for indicating the scale position is arranged on the scale indication member.

By adopting the scheme, the scale indicating component 421 indicates the corresponding scale of the push rod 2 in the cylinder 1, so that the sampler can sample more accurately.

According to another embodiment of the present invention, as shown in fig. 2-3, the scale indicating member 421 comprises a scale magnifying lens.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing is a more detailed description of the invention, and the specific embodiments thereof are not to be considered as limiting. Various changes in form and detail, including simple deductions or substitutions, may be made by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. An injector, comprising: the device comprises a barrel, a push rod arranged in the barrel and a push head arranged at one end of the push rod and positioned outside the barrel; it is characterized in that the preparation method is characterized in that,

the first end of the positioning component is fixedly connected to the position, close to the pushing head, of the pushing rod, and the second end of the positioning component is movably connected to the outer wall of the cylinder body; moreover, the push rod slides up and down in the cylinder body, so that the second end of the positioning component slides up and down outside the cylinder body;

the second end is provided with a locking member, when the locking member is in a locking state, the position of the second end relative to the outer wall of the barrel body is locked, and the relative position of the push rod in the barrel body is fixed.

2. The sample injector of claim 1, in which the first end of the positioning member is removably fixedly attached to the push rod.

3. The sample injector of claim 2, in which the positioning member comprises a cylinder parallel to the extension of the push rod.

4. The sample injector of claim 3, in which the positioning member comprises a first portion connected to the first end, a second portion connected to the second end; the first portion and the second portion are removably fixedly connected.

5. The sample injector of claim 3, in which the positioning member comprises a first portion connected to the first end, a second portion connected to the second end; the first part is rotationally connected with the second part; the connecting part of the first part and the second part is also provided with a fixing component which is used for locking the connecting state of the first part and the second part.

6. The sample injector of claim 1, in which the second end of the positioning member comprises a ring that mates with the barrel and fits over an outer wall of the barrel; an opening is arranged on one side of the ring; the locking member adjusts the distance between the two ends of the opening to the minimum, and locks the position of the ring relative to the outer wall of the barrel.

7. The sample injector of claim 6, wherein the two ends of the opening are respectively provided with a connecting member protruding from the ring; the locking member is disposed on the connecting member.

8. The sample injector of claim 6, wherein the locking member comprises an adjusting ring disposed on the outer periphery of the ring and rotatably connected to the ring, and a pressing shaft disposed between the ring and the adjusting ring and near the opening, wherein a groove matched with the pressing shaft is disposed in the adjusting ring at a position connected to the pressing shaft, and the depth of the groove is gradually reduced in a smooth transition manner.

9. The sample injector of any of claims 1-8, wherein a scale is disposed on the barrel, and a scale indication member is disposed on the second end of the positioning member at a position corresponding to the scale.

10. The sample injector of claim 9, in which the scale indicating member comprises a scale magnifier.