CN112807529A

CN112807529A - Automatic injection device for liquid medicine

Info

Publication number: CN112807529A
Application number: CN202110183541.2A
Authority: CN
Inventors: 卢旭华; 吴维清; 王海滨; 杨海松; 王亮; 孙钰岭; 王晨峰; 张帮可; 韩霖; 马宏道; 李奇晟
Original assignee: Shanghai Changzheng Hospital
Current assignee: Shanghai Changzheng Hospital
Priority date: 2021-02-10
Filing date: 2021-02-10
Publication date: 2021-05-18

Abstract

The invention relates to an automatic liquid medicine injection device, which comprises an injection device contact part, an injection device middle shell, an injection device tail shell, a movable sliding block, an elastic sheet, a tail power spring, a middle stable buffer spring and a built-in injector, wherein the injection device middle shell is arranged outside the built-in injector, the injection device tail shell is connected with the tail end of the injection device middle shell, the injection device contact part is connected with the front end of the injection device middle shell, the elastic sheet and the tail power spring are both arranged in the injection device tail shell, the front end of the movable sliding block is arranged between the injection device contact part and the injection device middle shell, the rear end of the injection device is arranged between the built-in injector and the middle shell of the injection device, and when the movable sliding block moves to ensure that the elastic sheet does not abut against the tail power spring any more, the tail power spring pushes the piston of the built-in injector to realize liquid medicine injection. The invention has the advantages of simple structure, reasonable cost, safety, reliability, convenient assembly and disassembly, repeated use and the like.

Description

Automatic injection device for liquid medicine

Technical Field

The invention belongs to the technical field of medical instruments, and particularly relates to an automatic liquid medicine injection device.

Background

Under the condition that severe trauma, hemorrhagic shock, severe pain and the like need to be treated, if other medical personnel or other personnel help does not exist, the wounded personnel are often required to inject some emergency medicines to carry out self rescue. Some common emergency medications include intramuscular injectable epinephrine, atropine, and the like.

At present, automatic liquid medicine injection devices are available at home and abroad, one type of automatic liquid medicine injection device can even realize voice prompt in daily use through an electric drive automatic injection device, but in daily first aid or battlefield first aid, wounded persons often need to judge and dispose quickly, and the electric drive device is not reliable enough and has higher cost under extreme environments, so that the automatic liquid medicine injection device is inconvenient for large-scale production and popularization and is particularly not suitable for the military field. The other type of automatic liquid medicine injection device is a mechanical power type automatic injection device, but most of the automatic liquid medicine injection devices have the problem of relatively complex structure, can not be disassembled and assembled by self, cannot be used when individual accessories of the mechanical power type automatic injection device are damaged, and cannot be effectively disassembled and reused.

Therefore, the automatic liquid medicine injection device which has the characteristics of simple structure, reasonable cost, safety, reliability, convenient disassembly, reusability and the like is designed, the problem of medicine injection under the emergency condition in normal times or wartime can be solved, and the automatic liquid medicine injection device is particularly significant for on-site emergency treatment.

Disclosure of Invention

The invention aims to solve part of defects of the automatic liquid medicine injection device in the prior art, realize the integral optimization of performance and provide the automatic liquid medicine injection device.

The automatic liquid medicine injection device has the characteristics of simple structure, reasonable cost, safety, reliability, convenience in disassembly, reusability and the like, can solve the problem of medicine injection under the emergency condition at ordinary times or in wartime, is particularly suitable for being used under the condition of on-site emergency, and can provide a safe and quick mode for on-site emergency.

The purpose of the invention can be realized by the following technical scheme:

the invention provides an automatic liquid medicine injection device, which comprises an injection device contact part, an injection device middle shell, an injection device tail shell, a movable sliding block, an elastic sheet, a tail power spring, a middle stable buffer spring and a built-in injector, wherein the built-in injector is internally provided with a containing cavity for containing liquid medicine, the tail end of the built-in injector is provided with a piston for pushing the liquid medicine to flow out, the front end of the built-in injector is provided with a liquid medicine outlet, the injection device middle shell is arranged on the outer side of the built-in injector, the front end of the injection device middle shell is provided with a detachable injection needle head communicated with the liquid medicine outlet of the built-in injector, the injection device tail shell is connected with the tail end of the injection device middle shell, the injection device contact part is connected with the front end of the injection device middle shell, and the injection device contact part is provided with a needle hole, the injection device comprises an injection device, a tail shell, a movable sliding block, a spring piece, a tail power spring, a plurality of middle stable buffer springs and a plurality of middle stable buffer springs, wherein the spring piece and the tail power spring are both arranged in the tail shell of the injection device, one end of the spring piece is fixed in the tail shell of the injection device, the other end of the spring piece is used for abutting against the tail power spring, under the action of the spring piece, the tail power spring is in a compressed state in a non-injection state, the front end of the movable sliding block is arranged between a contact part of the injection device and the middle shell of the injection device, the middle rear end of the movable sliding block is arranged between an internal injector and the middle shell of the injection device, the middle stable buffer springs are arranged between the contact part of the injection device and the movable sliding block and between the movable sliding block and the middle shell of the injection device respectively, the detachable injection needle head extends out of a needle hole of a contact part of the injection device and is used for pricking an injection part, the movable sliding block can move along the length direction of the built-in injector, and when the movable sliding block moves to push the elastic sheet to enable the elastic sheet not to abut against the tail power spring any more, the tail power spring stretches and pushes a piston of the built-in injector, so that liquid medicine in the built-in injector flows out of the detachable injection needle head.

In one embodiment of the present invention, the injection device contact portion is provided with a slide groove along a longitudinal direction of the built-in injector, the front end of the movable slider is disposed in the slide groove of the injection device contact portion and is movable along the slide groove of the injection device contact portion, the injection device middle housing is provided with a slide groove along the longitudinal direction of the built-in injector, and the middle portion of the movable slider is disposed in the slide groove of the injection device middle housing and is movable along the slide groove of the injection device middle housing.

In one embodiment of the present invention, a slide block is disposed at a front end of the movable slide block, and the slide block at the front end of the movable slide block is located in a slide groove of the contact portion of the injection device and is limited by the slide groove, so as to prevent the movable slide block from rotating in the injection device.

In one embodiment of the present invention, a sliding block is disposed in the middle of the movable sliding block, and the sliding block in the middle of the movable sliding block is located in a sliding groove of a middle housing of the injection device and is limited by the sliding groove, so as to prevent the movable sliding block from rotating in the injection device.

In one embodiment of the invention, the middle stable buffer springs are arranged along the length direction of the built-in injector and are respectively positioned between the tail end of the contact part of the injection device and the middle part of the movable slide block and between the middle part of the movable slide block and the tail end of the middle shell of the injection device.

In one embodiment of the present invention, the middle housing of the injection device is provided with a visual window or is made of transparent material, and the built-in syringe is made of transparent material for observing the injection condition of the liquid medicine.

In an embodiment of the invention, a connection fitting is arranged in the injection device tail shell, the injection device tail shell is further provided with a clamping groove for accommodating a tail power spring, the tail power spring is compressed between the connection fitting and the clamping groove, the connection fitting and a piston of the built-in injector are coaxially arranged or released, one end of the elastic sheet is fixed in the injection device tail shell, the other end of the elastic sheet is clamped on the connection fitting, when the movable sliding block pushes the elastic sheet to separate the elastic sheet from the connection fitting, the connection fitting is not clamped by the elastic sheet, the tail power spring stretches, and the piston of the built-in injector is pushed by the connection fitting to realize that the liquid medicine in the built-in injector flows out from the detachable injection needle.

In an embodiment of the invention, the elastic sheet is a metal elastic sheet.

In one embodiment of the invention, the injection device tail housing is provided with threads on the inner side, the injection device middle housing is provided with threads on the outer side of the tail end, and the injection device tail housing and the injection device middle housing are connected through threads.

In one embodiment of the invention, the injection device further comprises an injection device head cover connected to the front end of the middle housing of the injection device for preventing the leakage of the removable injection needle.

In one embodiment of the invention, the connection between the injection device head cover and the injection device middle housing is preferably selected to be a snap connection, which facilitates the mounting and dismounting of the injection device head cover.

The functions of the respective parts in the automatic liquid medicine injection device of the present invention are further explained as follows:

injection device head cap: protecting the injection needle from leaking.

Injection device contact part: is in direct contact with the injection site and can slide inwards to push the movable slide block.

Injection device middle part shell: the injection device has the advantages that the protection effect is achieved, the internal thread is arranged on the front portion of the middle shell of the injection device, the outer thread is arranged at the bottom of the detachable injection needle, the detachable injection needle can be tightly connected to the front portion of the middle shell of the injection device in a threaded connection mode, and meanwhile, the movable sliding block and the middle stabilizing buffer spring are arranged.

Injection device tail housing: play the guard action, hold afterbody power spring and shell fragment and insert wherein.

Moving the sliding block: to push the adjacent spring plate to release the tail power spring.

Spring plate: the tail power spring is blocked before injection to prevent the tail power spring from releasing, and the tail power spring is released after being pushed by the movable sliding block.

A tail power spring: for pushing the piston after release to provide the power for auto-injection.

The middle part stabilizes the buffer spring: the injection needle has a stable buffering effect during pressing injection, and prevents the injection needle from being broken due to instability caused by too fast penetration.

A built-in injector: for containing a medical fluid and for injecting the medical fluid; meanwhile, the front end of the built-in injector and the detachable injection needle head are tightly combined by rotation through threads.

Connecting fittings: the function of connecting the tail power spring and the elastic sheet is achieved.

A chute: play the connection effect and the stabilizing action, prevent to remove the slider and rotate in injection device.

Threading: the injection device tail shell can be tightly connected with the injection device middle shell in a rotating mode.

The injection needle can be assembled and disassembled: the bottom end of the injection device is internally and externally provided with threads, the inner threads help the injection device to be tightly combined with the built-in injector, and the outer threads help the built-in injector and the whole detachable injection needle to be tightly combined with the front end of the middle shell of the injection device.

The use mode of the automatic liquid medicine injection device is introduced as follows:

the user first pulls out the injection device head cover and presses the injection device contact part directly and vertically to the injection site (e.g. outer thigh). In the pressing process, the detachable syringe needle gradually pricks into the skin and pushes the movable sliding block. The movable sliding block pushes the elastic sheet, after the elastic sheet is pressed to a certain degree, the elastic sheet is pushed away by the movable sliding block, and the tail power spring is released. At the moment, the contact part of the injection device slides backwards, and the tail power spring pushes the piston forwards and pushes the liquid medicine into muscles continuously. In the process, the injection condition of the liquid medicine can be observed through a windowing or transparent structure at the side of the middle shell of the injection device, once accessories such as a tail power spring and the like are damaged or the tail power spring is triggered to cause the failure, the tail shell of the injection device is turned off, and the liquid medicine can be manually pushed in.

The automatic liquid medicine injection device is pressed after the contact of the injection part, so that the power device can be triggered to realize the automatic injection of the medicine, and the automatic liquid medicine injection device has the advantages of convenience, rapidness, effectiveness and the like.

The automatic injection device has the advantages of low cost, suitability for large-scale production, particular suitability for application on a battlefield, simple structure, modular composition, self-loading and unloading, repeated use and the like, and once individual parts are damaged, the parts can be independently replaced for normal use.

Compared with the prior art, the invention has the following advantages:

1) simple structure and reasonable cost. The invention has the advantages of few basic components, clear and simple structure, no complicated process and expensive materials, low whole production cost and convenient large-scale production and popularization.

2) Safe and reliable, convenient dismantlement. The electric energy drive is often unable to use because the battery is dead or because of being easy to cause under extreme circumstances etc. but the invention adopts mechanical power type drive, only need press to trigger the back by the spring drive. Meanwhile, the detachable injection needle and the built-in injector can be automatically detached, assembled and replaced, so that the reuse is realized, and even if the drive of the latter cannot be triggered, a user can also automatically detach the injector and try to trigger the drive again or manually.

Drawings

FIG. 1 is a schematic vertical sectional view of an automatic injection device for a liquid medicine according to embodiment 1 of the present invention;

FIG. 2 is a schematic horizontal sectional view of an automatic injection device for a liquid medicine according to embodiment 1 of the present invention;

FIG. 3 is a schematic diagram of a vertical cross-sectional structure of an automatic injection device for Chinese medicinal liquids in example 1 of the present invention with a head cover removed;

FIG. 4 is a schematic cross-sectional view taken at A in FIG. 3;

FIG. 5 is a schematic cross-sectional view of FIG. 3 at B;

FIG. 6 is a schematic cross-sectional view taken at C in FIG. 3;

FIG. 7 is a schematic cross-sectional view taken at D in FIG. 3;

fig. 8 is a schematic cross-sectional view of the structure at E in fig. 3.

The reference numbers in the figures indicate: 1. an injection device head cover; 2. an injection device contact portion; 3. an injection device mid-housing; 4. an injection device tail housing; 5. moving the slide block; 6. a spring plate; 7. a tail power spring; 8. a middle stable buffer spring; 9. a built-in injector; 10. a connection fitting; 11. a chute; 12. a thread; 13. the injection needle can be assembled and disassembled.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

Examples

Referring to fig. 1 to 8, the present embodiment provides an automatic liquid medicine injection device, including an injection device contact portion 2, an injection device middle housing 3, an injection device tail housing 4, a movable slider 5, a spring plate 6, a tail power spring 7, a middle stable buffer spring 8 and an internal syringe 9, wherein the internal syringe 9 is a cavity for containing liquid medicine, the tail end of the internal syringe 9 is a piston for pushing the liquid medicine to flow out, the front end of the internal syringe 9 is a liquid medicine outlet, the injection device middle housing 3 is disposed outside the internal syringe 9, the front end of the injection device middle housing 3 is provided with a detachable injection needle 13 communicated with the liquid medicine outlet of the internal syringe 9, the injection device tail housing 4 is connected to the tail end of the injection device middle housing 3, the injection device contact portion 2 is connected to the front end of the injection device middle housing 3, and the injection device contact part 2 is provided with a pinhole for passing a detachable injection needle 13, the elastic sheet 6 and the tail power spring 7 are both arranged in the injection device tail shell 4, one end of the elastic sheet 6 is fixed in the injection device tail shell 4, the other end of the elastic sheet 6 is used for abutting against the tail power spring 7 under the action of the elastic sheet 6, the tail power spring 7 is in a compression state under the non-injection state, the front end of the movable slide block 5 is arranged between the injection device contact part 2 and the injection device middle shell 3, the middle rear end of the movable slide block 5 is arranged between the built-in injector 9 and the injection device middle shell 3, a plurality of middle stable buffer springs 8 are arranged and are respectively positioned between the injection device contact part 2 and the movable slide block 5 and between the movable slide block 5 and the injection device middle shell 3, the injection device contact part 2 can move along the length direction of the built-in injector 9, when the injection device contact part 2 pushes the movable slide block 5 to compress the middle stable buffer spring 8 between the injection device contact part 2 and the movable slide block 5, the detachable injection needle 13 extends out of a needle hole of the injection device contact part 2 to prick an injection part, the movable slide block 5 can move along the length direction of the built-in injector 9, and when the movable slide block 5 moves to push the elastic sheet 6 to ensure that the elastic sheet 6 is not propped against the tail power spring 7, the tail power spring 7 stretches and pushes a piston of the built-in injector 9 to realize that the liquid medicine in the built-in injector 9 flows out of the detachable injection needle 13.

In this embodiment, the injection device contact portion 2 is provided with a sliding groove 11 along the length direction of the built-in injector 9, the front end of the movable slider 5 is disposed in the sliding groove 11 of the injection device contact portion 2 and can move along the sliding groove 11 of the injection device contact portion 2, the injection device middle housing 3 is provided with a sliding groove 11 along the length direction of the built-in injector 9, and the middle of the movable slider 5 is disposed in the sliding groove 11 of the injection device middle housing 3 and can move along the sliding groove 11 of the injection device middle housing 3.

In this embodiment, the front end of the movable slider 5 is provided with a slider, and the slider at the front end of the movable slider 5 is located in the sliding groove 11 of the contact portion 2 of the injection device and is limited by the sliding groove 11, so as to prevent the movable slider 5 from rotating in the injection device.

In this embodiment, a sliding block is arranged in the middle of the movable sliding block 5, and the sliding block in the middle of the movable sliding block 5 is located in a sliding groove 11 of the middle housing 3 of the injection device and is limited by the sliding groove 11, so that the movable sliding block 5 is prevented from rotating in the injection device.

In this embodiment, the middle stable buffer springs 8 are all arranged along the length direction of the built-in injector 9 and are respectively located between the tail end of the injection device contact part 2 and the middle of the movable slider 5 and between the middle of the movable slider 5 and the tail end of the injection device middle housing 3.

In this embodiment, the middle housing 3 of the injection device is provided with a visual window or made of transparent material, and the built-in syringe is made of transparent material for observing the injection condition of the liquid medicine.

In this embodiment, a connection fitting 10 is disposed in the injection device tail housing 4, the injection device tail housing 4 is further provided with a slot for accommodating the tail power spring 7, the tail power spring 7 is compressed between the connection fitting 10 and the slot, the connection fitting 10 and the piston of the built-in injector 9 are coaxially disposed or the piston of the built-in injector 9 is released, one end of the elastic sheet 6 is fixed in the injection device tail housing 4, and the other end of the elastic sheet 6 is clamped on the connection fitting 10, when the movable slider 5 pushes the elastic sheet 6 to separate the elastic sheet 6 from the connection fitting 10, the connection fitting 10 is no longer clamped by the elastic sheet 6, the tail power spring 7 stretches, and pushes the piston of the built-in injector 9 through the connection fitting 10, so as to enable the liquid medicine in the built-in injector 9 to flow out from the detachable injection needle 13.

In this embodiment, the elastic sheet 6 is a metal elastic sheet.

In this embodiment, the inner side of the injection device tail housing 4 is provided with threads 12, the outer side of the tail end of the injection device middle housing 3 is provided with threads 12, and the injection device tail housing 4 is connected with the injection device middle housing 3 through the threads 12.

In this embodiment, the automatic liquid medicine injection device further comprises an injection device head cover 1, and the injection device head cover 1 is connected to the front end of the injection device middle housing 3 and used for preventing the leakage of the removable injection needle 13.

In this embodiment, the connection mode between the injection device head cover 1 and the injection device middle housing 3 is selected as a snap connection, so that the injection device head cover 1 can be conveniently covered and removed.

The functions of the respective components in the automatic liquid medicine injection device of the present embodiment are further explained as follows:

injection device head cap 1: protecting the detachable injection needle 13 from leaking.

Injection device contact portion 2: is in direct contact with the injection site and can slide inwards to push the movable slide block.

Injection device middle housing 3: the injection device has the advantages that the protection effect is achieved, the internal thread is arranged on the front portion of the middle shell of the injection device, the outer thread is arranged at the bottom of the detachable injection needle, the detachable injection needle can be tightly connected to the front portion of the middle shell of the injection device in a threaded connection mode, and meanwhile, the movable sliding block and the middle stabilizing buffer spring are arranged.

Injection device tail housing 4: play the guard action, hold afterbody power spring and shell fragment and insert wherein.

Moving the sliding block 5: to push the adjacent spring plate to release the tail power spring.

Spring plate 6: the tail power spring is blocked before injection to prevent the tail power spring from releasing, and the tail power spring is released after being pushed by the movable sliding block.

Tail power spring 7: for pushing the piston after release to provide the power for auto-injection.

Middle stable buffer spring 8: the injection needle has a stable buffering effect during pressing injection, and prevents the injection needle 13 from being broken due to instability caused by too fast penetration.

A built-in injector 9: for containing a medical fluid and for injecting the medical fluid; meanwhile, the front end of the built-in injector 9 and the detachable injection needle 13 are tightly combined by rotation through threads.

The connection fitting 10: the function of connecting the tail power spring and the elastic sheet is achieved.

The sliding groove 11: play the connection effect and the stabilizing action, prevent to remove the slider and rotate in injection device.

The thread 12: the injection device tail shell can be tightly connected with the injection device middle shell in a rotating mode.

Detachable injection needle 13: the bottom end of the injection device is internally and externally provided with threads, the inner threads help the injection device to be tightly combined with the built-in injector 9, and the outer threads help the built-in injector 9 and the whole body of the detachable injection needle 13 to be tightly combined with the front end of the middle shell 3 of the injection device.

the user first pulls out the injection device head cover and presses the injection device contact part directly and vertically to the injection site (e.g. outer thigh). In the pressing process, the detachable injection needle 13 gradually pricks into the skin to push the movable slide block. The movable sliding block pushes the elastic sheet, after the elastic sheet is pressed to a certain degree, the elastic sheet is pushed away by the movable sliding block, and the tail power spring is released. At the moment, the contact part of the injection device slides backwards, and the tail power spring pushes the piston forwards and pushes the liquid medicine into muscles continuously. In the process, the injection condition of the liquid medicine can be observed through a windowing or transparent structure at the side of the middle shell of the injection device, once accessories such as a tail power spring and the like are damaged or the tail power spring is triggered to cause the failure, the tail shell of the injection device is turned off, and the liquid medicine can be manually pushed in.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Claims

1. An automatic injection device of liquid medicine is characterized by comprising an injection device contact part (2), an injection device middle shell (3), an injection device tail shell (4), a movable sliding block (5), an elastic sheet (6), a tail power spring (7), a middle stable buffer spring (8) and a built-in injector (9),

the inner part of the built-in syringe (9) is a containing cavity for containing liquid medicine, the tail end of the built-in syringe (9) is a piston for pushing the liquid medicine to flow out, the front end of the built-in syringe (9) is a liquid medicine outlet,

the middle shell (3) of the injection device is arranged at the outer side of the built-in injector (9), the front end of the middle shell (3) of the injection device is provided with a detachable injection needle (13) communicated with a liquid medicine outlet of the built-in injector (9),

the tail shell (4) of the injection device is connected with the tail end of the middle shell (3) of the injection device,

the injection device contact part (2) is connected with the front end of the middle shell (3) of the injection device, a needle hole for assembling and disassembling an injection needle (13) is arranged on the injection device contact part (2),

the elastic sheet (6) and the tail power spring (7) are both arranged in the tail shell (4) of the injection device, one end of the elastic sheet (6) is fixed in the tail shell (4) of the injection device, the other end of the elastic sheet is used for abutting against the tail power spring (7) and is under the action of the elastic sheet (6), the tail power spring (7) is in a compressed state under the non-injection state,

the front end of the movable sliding block (5) is arranged between the contact part (2) of the injection device and the middle shell (3) of the injection device, the middle rear end of the movable sliding block (5) is arranged between the built-in injector (9) and the middle shell (3) of the injection device,

a plurality of middle stable buffer springs (8) are arranged and are respectively positioned between the contact part (2) of the injection device and the movable slide block (5) and between the movable slide block (5) and the middle shell (3) of the injection device,

the injection device contact part (2) can move along the length direction of the built-in injector (9), when the injection device contact part (2) pushes the movable slide block (5) to compress the middle stable buffer spring (8) between the injection device contact part (2) and the movable slide block (5), the detachable injection needle (13) extends out of the needle hole of the injection device contact part (2) to prick into an injection part,

the movable sliding block (5) can move along the length direction of the built-in syringe (9), when the movable sliding block (5) moves to push the elastic sheet (6) to ensure that the elastic sheet (6) is not propped against the tail power spring (7), the tail power spring (7) stretches and pushes the piston of the built-in syringe (9), so that the liquid medicine in the built-in syringe (9) flows out from the detachable injection needle (13).

2. An automatic medical liquid injection device according to claim 1, wherein the injection device contact portion (2) is provided with a slide groove (11) along the length direction of the built-in syringe (9), the front end of the movable slider (5) is disposed in the slide groove (11) of the injection device contact portion (2) and is movable along the slide groove (11) of the injection device contact portion (2), the injection device middle housing (3) is provided with a slide groove (11) along the length direction of the built-in syringe (9), and the middle of the movable slider (5) is disposed in the slide groove (11) of the injection device middle housing (3) and is movable along the slide groove (11) of the injection device middle housing (3).

3. An automatic liquid medicine injection device according to claim 2, wherein the front end of the movable slider (5) is provided with a slider, and the slider at the front end of the movable slider (5) is positioned in the sliding groove (11) of the contact part (2) of the injection device and is limited by the sliding groove (11) to prevent the movable slider (5) from rotating in the injection device.

4. An automatic liquid medicine injection device according to claim 2, characterized in that the middle of the movable slider (5) is provided with a slider, and the slider in the middle of the movable slider (5) is positioned in the chute (11) of the middle housing (3) of the injection device and is limited by the chute (11) to prevent the movable slider (5) from rotating in the injection device.

5. An automatic liquid medicine injection device according to claim 1, wherein the middle stabilizing buffer springs (8) are arranged along the length direction of the built-in syringe (9) and are respectively positioned between the tail end of the injection device contact part (2) and the middle part of the movable slider (5) and between the middle part of the movable slider (5) and the tail end of the injection device middle shell (3).

6. An automatic liquid medicine injection device according to claim 1, characterized in that the middle housing (3) of the injection device is provided with a visual window or is made of transparent material, and the built-in injector is made of transparent material.

7. The automatic liquid medicine injection device according to claim 1, wherein a connection fitting (10) is provided in the injection device tail housing (4), the injection device tail housing (4) is further provided with a slot for accommodating the tail power spring (7), the tail power spring (7) is compressed between the connection fitting (10) and the slot, the connection fitting (10) and the piston of the built-in syringe (9) are coaxially arranged or the piston of the built-in syringe (9) is released, one end of the elastic sheet (6) is fixed in the injection device tail housing (4), the other end is clamped on the connection fitting (10), when the movable slider (5) pushes the elastic sheet (6) to separate the elastic sheet (6) from the connection fitting (10), the tail power spring (7) stretches, the piston of the built-in syringe (9) is pushed through the connection fitting (10), so as to realize the liquid medicine in the built-in syringe (9) to flow out from the detachable injection needle (13).

8. An automatic liquid medicine injection device according to claim 1, wherein said resilient piece (6) is a metal resilient piece.

9. An automatic liquid medicine injection device according to claim 1, characterized in that the injection device tail housing (4) is provided with threads (12) on the inside and the injection device middle housing (3) is provided with threads (12) on the outside of the tail end, and the injection device tail housing (4) and the injection device middle housing (3) are connected through the threads (12).

10. An automatic medical liquid injection device according to claim 1, further comprising an injection device head cover (1), said injection device head cover (1) being attached to the front end of the injection device middle housing (3) for preventing the leakage of the removable injection needle (13).