CN209734664U

CN209734664U - Injection pen

Info

Publication number: CN209734664U
Application number: CN201821973253.7U
Authority: CN
Inventors: 韩毅涛; 王艳; 姚小龙; 黄伟; 陶安进; 李国安
Original assignee: GANSU CHENGJI BIOPHARMACEUTICAL CO Ltd
Current assignee: GANSU CHENGJI BIOPHARMACEUTICAL CO Ltd
Priority date: 2018-11-27
Filing date: 2018-11-27
Publication date: 2019-12-06
Anticipated expiration: 2028-11-27

Abstract

The utility model discloses an injection pen, include: the device comprises a shell, wherein a cartridge bottle medicine needle assembly and a brake device are arranged in the shell; the safety cap is arranged at one end of the shell and used for preventing the brake device from being triggered by mistake; the trigger needle shield is sleeved between the shell and the brake device, and an elastic piece for driving the trigger needle shield to move to hide an injection needle of the cartridge bottle and medical needle assembly after injection is arranged between the trigger needle shield and the shell; the trigger needle shield is clamped with the brake device before injection so as to prevent the trigger needle shield from being popped up by the elastic piece before injection; the trigger needle shield and the detent can be disengaged during movement of the cartridge vial needle assembly. The utility model provides a trigger needle cover and arresting gear can combine and separable, and the safety cap that utilizes the mistake proofing arresting gear that touches prevents that the trigger needle cover is prevented by the mistake and triggered and is released to can solve the problem that the trigger needle cover was popped out before the injection, in order to ensure integrality and the security of injection pen in transportation and storage process.

Description

Injection pen

Technical Field

The utility model relates to the technical field of medical equipment, more specifically say, relate to an injection pen.

background

With the annual increase of the prevalence rate of sudden diseases such as cardiovascular and cerebrovascular diseases, the injection pen for self-management of the sudden diseases is gradually applied.

Such a first-aid injection pen is usually pre-equipped with a cartridge and an injection needle, and has a brake device to enable a one-touch auto-injection function. Meanwhile, in order to reduce the fear of the needle and the psychological stress of the user, the injection pen generally includes a needle hiding member for hiding the injection needle.

the end of the needle hiding piece in the prior art is usually provided with four buckles, and the four buckles and four clamping grooves arranged in the shell are in one-to-one correspondence and can be clamped and separated, so that the needle hiding piece and the shell can be combined and separated. When the safety cap is pulled off and injection is carried out, the hidden needle piece collides with an injection position and applies pressure to the hidden needle piece so that the hidden needle piece moves relative to the shell, the brake device is triggered to act, and finally injection is finished; meanwhile, when the needle hiding piece moves relative to the shell, the four buckles are folded towards the axis of the needle hiding piece, so that the four buckles are separated from the clamping groove on the shell, the needle hiding piece is separated from the shell, and the needle hiding piece is released. When the pressure applied to the needle hiding piece is released, the needle hiding piece is driven to pop out for a certain distance in the opposite direction relative to the shell under the action of the elastic piece connected with the needle hiding piece, so that the injection needle is hidden.

However, in the injection pen with such a structure, under the action of an external force, the needle hiding piece is easily separated from the housing and released, that is, the needle hiding piece is difficult to keep the position before injection unchanged all the time, so that false triggering is easily caused, and the integrity and safety of the injection pen during transportation, storage and use are difficult to guarantee.

In summary, it is an urgent need to solve the above-mentioned problems by those skilled in the art to provide an injection pen capable of preventing the hidden needle from being triggered by mistake.

SUMMERY OF THE UTILITY MODEL

In view of this, the present invention provides an injection pen, which can solve the problem of misoperation of triggering a needle shield before injection, so as to ensure the integrity and safety of the injection pen during transportation and storage.

in order to achieve the above object, the present invention provides the following technical solutions:

An injection pen, comprising:

The device comprises a shell, a needle holder and a brake device, wherein the shell is internally provided with a cartridge bottle needle assembly and the brake device for driving the cartridge bottle needle assembly to move towards the injection direction;

The safety cap is arranged at one end of the shell and used for preventing the brake device from being triggered by mistake;

The trigger needle shield is sleeved between the shell and the braking device, and an elastic piece for driving the trigger needle shield to move to hide the injection needle after injection is arranged between the trigger needle shield and the shell; the trigger needle shield is clamped with the braking device before injection so as to prevent the trigger needle shield from being ejected by the elastic piece before injection; the trigger needle shield and the brake are separated during movement of the cartridge vial needle assembly.

Preferably, the braking device includes a cassette bottle holder which is sleeved in the trigger needle shield and used for accommodating the cassette bottle medicine needle assembly, the inner wall of the trigger needle shield is circumferentially provided with at least one first inward convex buckle, and the side wall of the cassette bottle holder is provided with:

the clamping grooves are used for being correspondingly clamped with the first buckles one by one;

the clamping type bottle comprises a clamping groove, a first elastic sheet, a first buckle and a second elastic sheet, wherein the clamping groove is formed in the bottom of the clamping groove, the first elastic sheet is arranged in the clamping groove in a suspended mode and has elasticity, the first elastic sheet can be radially placed into the clamping type bottle support under the extrusion of the first buckle, and the clamping type bottle medicine needle assembly can be radially placed out of the clamping type bottle support when moving to the clamping groove, so that the first buckle is separated from the clamping groove.

preferably, the free end of the first elastic sheet is provided with a protruding portion for facilitating the separation of the first buckle from the clamping groove, and the protruding portion protrudes out of the inner wall of the cassette bottle support.

Preferably, the method further comprises the following steps:

The self-locking mechanism is arranged between the trigger needle shield and the shell and used for preventing the trigger needle shield from retreating after the trigger needle shield conceals the injection needle.

Preferably, the self-locking mechanism comprises:

The second buckle is provided with a clamping groove used for being clamped with the end part of the shell, and the second buckle has elasticity and can be radially and inwardly contracted under the extrusion of the end part of the shell, so that the end part of the shell can be finally matched and clamped with the clamping groove.

preferably, the outer peripheral part of the trigger needle shield is provided with a yielding groove corresponding to the second buckle one by one, and the second buckle comprises:

The second elastic sheet is connected with the first groove wall of the abdicating groove and obliquely protrudes out of the notch of the abdicating groove, the clamping groove is arranged at one end, far away from the first groove wall, of the second elastic sheet, the clamping groove is connected with the second groove wall of the abdicating groove, and the second groove wall is opposite to the first groove wall; the second elastic sheet can contract towards the inside of the yielding groove under the extrusion of the end part of the shell, and can restore elastic deformation when the extrusion force of the end part of the shell is relieved, so that the end part of the shell is clamped into the clamping groove.

Preferably, the cartridge vial and needle assembly comprises a cartridge vial and an injection needle, the cartridge vial and the injection needle being independently disposed within the housing.

preferably, the injection needle comprises:

The needle base and the double-edged needle body arranged on the needle base;

The sealing membrane is arranged at one end of the needle seat facing the bottle mouth part of the cassette bottle and used for sealing one end of the double-blade needle body;

and the needle protection cap is connected with the other end of the needle base and sleeved on the exposed peripheral part of the other end of the double-blade needle body, and the needle protection cap can be compressed.

The utility model provides an injection pen, because trigger the needle shield before the injection and link to each other with arresting gear, and the casing is kept away from the one end of triggering the needle shield and is equipped with the safety cap that is used for preventing the false triggering arresting gear, consequently, under the effect of safety cap, even if trigger the needle shield and be triggered by the mistake, can not lead to the arresting gear action yet, trigger the needle shield and just can't separate with arresting gear yet, consequently, the elastic component can't pop out trigger the needle shield to can guarantee integrality and the security of injection pen in transportation and storage process; when the safety cap is pulled out during injection, the trigger needle shield collides with an injection position to trigger the brake device, injection is completed under the action of the brake device, and the trigger needle shield can be separated from the brake device and released when the cassette bottle medicine needle assembly moves in the injection process.

That is to say, compare in the prior art and adopt trigger needle cover and casing joinable and separable connected mode, trigger needle cover and arresting gear can combine and separable, utilize the safety cap that prevents mistake and touch arresting gear to prevent that trigger needle cover from being triggered by mistake and being released to can solve the problem that trigger needle cover was popped out before the injection, in order to ensure the integrality and the security of injection pen in transportation and storage process.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a cross-sectional view of an embodiment of an injection pen provided by the present invention;

FIG. 2 is an exploded view of the injection pen of FIG. 1;

FIG. 3 is a partial schematic view of A of FIG. 1;

Fig. 4 is a partial schematic view of the trigger needle shield and the housing in a locked state B in fig. 3.

The reference numerals in fig. 1 to 4 are as follows:

the device comprises a shell 1, a front shell 11, a rear shell 12, a cassette bottle 2, an injection needle 3, a needle seat 31, a safety cap 4, a trigger needle cover 5, a first buckle 51, an abdicating groove 52, a second buckle 53, an elastic piece 6, a cassette bottle bracket 71, a clamping groove 711, a first elastic piece 712, a boss 713, a sleeve 72, a push rod 73, a power spring 74 and a sealing ring 8.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

the core of the utility model is to provide an injection pen, can solve the maloperation problem that triggers the needle cover before the injection to ensure the integrality and the security of injection pen in transportation and storage process.

referring to fig. 1-4, fig. 1 is a sectional view of an embodiment of an injection pen provided by the present invention; FIG. 2 is an exploded view of the injection pen of FIG. 1; FIG. 3 is a partial schematic view of A of FIG. 1; fig. 4 is a partial schematic view of the trigger needle shield and the housing in a locked state B in fig. 3.

The utility model provides an injection pen, including casing 1 with locate card type bottle medicine needle subassembly and arresting gear in the casing 1, card type bottle medicine needle subassembly can remove 1 casing relatively to under arresting gear's effect, remove towards the injection direction, and finally accomplish the injection.

one end of the housing 1 is provided with a safety cap 4 for preventing the brake device from being triggered by mistake, i.e. the brake device can be triggered only when the safety cap 4 is pulled out, and the brake device cannot be triggered when the safety cap 4 is not pulled out.

The other end of the shell 1 is sleeved with a trigger needle shield 5 which can move relative to the shell 1, the trigger needle shield 5 and the brake device can be combined and separated, in an initial state, namely before the injection pen is assembled and injected, the trigger needle shield 5 and the brake device are always in a combined state, during injection, the brake device can be triggered by enabling the trigger needle shield 5 to collide with an injection position, in the injection process, along with the movement of the medicine needle assembly of the card bottle, the trigger needle shield 5 can be separated from the brake device to release the trigger needle shield 5, so that the trigger needle shield 5 can be ejected outwards relative to the shell 1 under the action of an elastic piece 6 connected with the trigger needle shield after injection is completed, the injection needle 3 of the medicine needle assembly of the card bottle is shielded, and the injection needle 3 is hidden.

it can be understood that, when the trigger needle shield 5 is combined with the brake device, that is, before the trigger needle shield 5 is separated from the brake device, the elastic member 6 is always in a compressed state, so that the elastic member 6 has a certain elastic restoring force, and after the trigger needle shield 5 is separated from the brake device, the trigger needle shield 5 is driven to move under the action of the elastic restoring force of the elastic member 6, so that the injection needle 3 after injection is completely covered, and the accidental occurrences such as accidental puncture and the like caused by the exposure of the injection needle 3 are avoided.

In view of the simplicity and easy implementation of the specific structure of the elastic element 6, it is preferable that the elastic element 6 is a spring, the outer peripheral portion of the trigger needle shield 5 is provided with a shoulder for abutting against one end of the spring, and the inner peripheral portion of the housing 1 is provided with an abutting member for abutting against the other end of the spring.

The utility model discloses do not limit to arresting gear's concrete structure and theory of operation, can refer to prior art.

To sum up, the utility model provides an injection pen, because trigger needle shield 5 before the injection links to each other with arresting gear, and the one end that casing 1 kept away from trigger needle shield 5 is equipped with safety cap 4 that is used for preventing to trigger arresting gear by mistake, therefore, under the effect of safety cap 4, even if trigger needle shield 5 is triggered by mistake, can not lead to the arresting gear action yet, trigger needle shield 5 also can't separate with arresting gear, therefore, elastic component 6 can't pop out trigger needle shield 5, thus can guarantee integrality and security of injection pen in transportation and storage process; during injection, the safety cap 4 is pulled out, the trigger needle shield 5 collides with an injection position to trigger the brake device, injection is completed under the action of the brake device, and the trigger needle shield 5 can be separated from the brake device and released when the cartridge bottle medicine needle assembly moves in the injection process, so that after injection is completed and the trigger needle shield 5 is separated from the injection position, the elastic piece 6 can drive the trigger needle shield 5 to pop out towards the injection direction, the injection needle 3 is hidden after injection, and the problems of accidental puncture and the like caused by the exposure of the injection needle 3 are avoided.

That is to say, compare in the prior art and adopt trigger needle cover 5 and casing 1 joinable and separable connected mode, trigger needle cover 5 and arresting gear joinable and separable in the utility model, utilize the safety cap 4 that prevents the brake equipment of mistake touch to prevent that trigger needle cover 5 from being triggered by mistake and being released to can solve the problem that trigger needle cover 5 was popped out before the injection, in order to ensure the integrality and the security of injection pen in transportation and storage process.

It will be appreciated that the end of the trigger needle shield 5 is provided with an injection aperture and that the end of the housing 1 facing the trigger needle shield 5 is provided with a sealing ring 8.

In view of convenience of assembly, the housing 1 includes a front case 11 and a rear case 12.

in view of the simplicity of the specific structure of the stopper device and the ease of implementation, it is preferable that the stopper device includes a cartridge holder 71 and a sleeve 72 for accommodating the cartridge needle assembly, and it is preferable that the cartridge holder 71 and the sleeve 72 are respectively for accommodating the injection needle 3 and the cartridge 2 of the cartridge needle assembly for the convenience of assembly; the braking device further comprises a push rod 73 movably arranged in the sleeve 72 and connected to the cartridge 2, and a power spring 74 connected at one end to the push rod 73 and at the other end to the sleeve 72. The cassette bottle support 71 is sleeved in the trigger needle cover 5, one end, extending out of the trigger needle cover 5, of the cassette bottle support 71 is connected with the sleeve 72, the other end of the sleeve 72 can be clamped and separated with the push rod 73, one end, connected with the sleeve 72, of the push rod 73 is provided with a slot for inserting an insertion column of the safety cap 4, after the insertion column of the safety cap 4 is inserted into the slot, under the radial extrusion action of the insertion column, the push rod 73 is clamped with the sleeve 72, at the moment, the power spring 74 is in a compressed state and is locked between the push rod 73 and the sleeve 72, and the brake device cannot be triggered; when the safety cap 4 is pulled out, the plug column is separated from the slot, at this time, after the trigger needle shield 5 collides with the injection position, the cassette bottle support 71 is pushed to move in the direction opposite to the injection direction, the sleeve 72 is further pushed to be linked, the clamping part of the sleeve 72 and the clamping part of the push rod 73 are separated, so that the push rod 73 is completely released, the push rod 73 moves in the injection direction under the action of the power spring 74, the cassette bottle 2 and the injection needle 3 are pushed to move to the injection position, and finally, the injection is finished.

In consideration of the specific implementation manner that the trigger needle shield 5 and the braking device can be combined and separated, based on the above embodiment, the inner wall of the trigger needle shield 5 is circumferentially provided with at least one first buckle 51, the side wall of the cassette bottle bracket 71 is provided with a clamping groove 711 for clamping with the first buckle 51 in a one-to-one correspondence manner and a first elastic sheet 712 with elasticity, the first elastic sheet 712 is arranged in the clamping groove 711, the first elastic sheet 712 can radially extend into the cassette bottle bracket 71 under the extrusion action of the first buckle 51, and when the needle hub 31 of the injection needle 3 moves to the clamping groove 711, the first elastic sheet 712 can enable the first buckle 51 to be separated from the clamping groove 711 under the extrusion action of the needle hub 31.

That is to say, in the present embodiment, the first buckle 51 is clamped with the clamping groove 711 to realize the clamping combination of the trigger needle shield 5 and the cassette bottle bracket 71, and the first buckle 51 is separated from the clamping groove 711 by the first elastic sheet 712.

specifically, the first elastic piece 712 is a cantilever member in the slot 711, one end of the first elastic piece 712 is preferably integrated with a slot wall of the slot 711, and a certain distance is provided between the other end of the first elastic piece 712 and the other slot wall of the slot 711 corresponding to the other end of the first elastic piece 712, so as to avoid interfering with the swinging of the first elastic piece 712. The first elastic piece 712 has elasticity so that when the first buckle 51 is clamped into the clamping groove 711, the first elastic piece radially swings into the inside of the clamping bottle support 71 under the extrusion action of the first buckle 51 to avoid the first buckle 51, so that the first buckle 51 is clamped with the clamping groove 711.

during the injection, with the movement of the needle holder 31, when the needle holder 31 moves to the notch 711, because the needle holder 31 is in slidable fit connection with the inner wall of the cassette bottle holder 71, the first elastic sheet 712 is radially outwardly ejected under the radial extrusion action of the needle holder 31, so that the first buckle 51 is disengaged from the notch 711 under the forced radial force of the first elastic sheet 712, and the separation of the trigger needle shield 5 from the cassette bottle holder 71 is realized.

It can be understood that the number of the locking grooves 711, the first elastic pieces 712 and the first locking pieces 51 is equal, and the three are in one-to-one correspondence, that is, a single locking piece 51, the locking groove 711 and the first elastic piece 712 form a locking and separating locking set, and a plurality of locking sets may be arranged between the trigger needle shield 5 and the cassette bottle holder 71, and the locking sets may be uniformly distributed along the circumferential direction.

In consideration of the effect of the first elastic piece 712, on the basis of the above embodiment, the free end of the first elastic piece 712 is provided with a protrusion 713 for facilitating the first buckle 51 to be separated from the slot 711 and protruding out of the inner wall of the cassette bottle holder 71.

it is understood that the protrusion 713 may enable the first latch 51 to be quickly disengaged from the latch groove 711, so as to improve the sensitivity of the two to be separated. The side of the end of the protrusion 713 away from the first resilient piece 712 is chamfered to guide the needle 3 in the moving direction, so that the needle 3 can move smoothly.

In addition, in order to avoid that the trigger needle shield 5 is retracted to expose the injection needle 3 again due to misoperation after the trigger needle shield 5 hides the injection needle 3, on the basis of any one of the above embodiments, the method further comprises: and the self-locking mechanism is arranged between the trigger needle shield 5 and the shell 1 and is used for preventing the trigger needle shield 5 from retreating after the trigger needle shield 5 hides the injection needle 3.

that is, in the present embodiment, the trigger needle shield 5 is locked with the housing 1 by the self-locking mechanism, so as to prevent the trigger needle shield 5 from retracting into the housing 1 under the action of external force.

In view of the implementation manner of the self-locking mechanism, on the basis of the above embodiment, the self-locking mechanism includes at least one second buckle 53 disposed on the outer peripheral portion of the trigger needle shield 5, the second buckle 53 is provided with a clamping groove for clamping with the end portion of the housing 1, and the second buckle 53 has elasticity and can contract radially inwards under the pressing action of the end portion of the housing 1, so that the end portion of the housing 1 can be finally clamped with the clamping groove in a matching manner.

It can be understood that when the trigger needle shield 5 is clamped with the brake device, the second buckle 53 is located inside the housing 1, after the trigger needle shield 5 is separated from the brake device, and after injection, the trigger needle shield 5 is popped out by the elastic element 6, the end of the housing 1 extrudes the second buckle 53 to enable the second buckle 53 to be popped out of the housing 1, and at the moment when the second buckle 53 is separated from the end of the housing 1, due to the elastic restoring force, the end of the housing 1 is clamped with the clamping groove, so that the self-locking of the trigger needle shield 5 and the housing 1 is realized, and the trigger needle shield 5 cannot be retracted into the housing 1 under the action of external force.

on the basis of the above embodiment, the self-locking mechanism further includes an avoiding groove 52 which is provided at the outer circumferential portion of the trigger needle shield 5 and corresponds to the second buckle 53 one by one, and the avoiding groove 52 is used for avoiding the second buckle 53 when the second buckle 53 contracts radially inward.

The second buckle 53 comprises a second elastic sheet connected with the first groove wall of the abdicating groove 52, the second elastic sheet protrudes out of the notch of the abdicating groove 52 and inclines outwards from the first groove wall, the clamping groove is arranged at one end of the second elastic sheet far away from the first groove wall, the clamping groove is connected with the second groove wall of the abdicating groove 52, and the second groove wall is opposite to the first groove wall; the second elastic sheet can contract towards the inside of the abdicating groove 52 under the extrusion action of the end part of the shell 1, and after the extrusion force to the second elastic sheet is released by the end part of the shell 1, the second elastic sheet can pop out of the abdicating groove 52 to recover the elastic deformation, so that the end part of the shell 1 is clamped into the clamping groove. After the end of the shell 1 is clamped in the clamping groove, the end surface of the shell 1 abuts against the end of the second elastic sheet, so that when the needle shield 5 is triggered by misoperation, the triggering needle shield 5 cannot retreat under the abutting action of the end surface of the shell 1 and the second elastic sheet, and forms a locking state with the shell 1.

in view of the sterility and safety of the injection needle 3, the cartridge-based needle assembly comprises the cartridge 2 and the injection needle 3, and the cartridge 2 and the injection needle 3 are provided in the housing 1 independently of each other.

That is, after the cartridge 2 and the injection needle 3 are inserted into the injection pen in advance, the cartridge 2 and the injection needle 3 maintain their independence and package integrity, and the injection needle 3 is prevented from being soaked in the medical solution of the cartridge 2, causing contamination, and the like.

In view of the specific structure of the injection needle 3, on the basis of the above-mentioned embodiment, the injection needle 3 includes the needle holder 31 and the double-edged needle body provided on the needle holder 31, in order to ensure the safety and sterility of the injection needle 3, one end of the needle holder 311 is connected to the needle cap fitted over the exposed outer peripheral portion of one end of the injection needle 3, and the other end of the needle holder 31 is provided with the sealing film for sealing the other end of the injection needle 3 to completely seal the injection needle 3. The sealing membrane faces the mouth of the cartridge 2.

That is, the present embodiment achieves the sealing of both ends of the injection needle 3 by the needle protection cap and the sealing film, respectively, and achieves the effect of completely sealing the injection needle 3 in combination with the needle holder 31.

during injection, under the action of the braking device, the bottle mouth part of the card type bottle 2 firstly punctures the sealing film and continuously moves to enable the double-edged needle body to puncture the bottle mouth part, after the double-edged needle body punctures the bottle mouth part and the card type bottle 2 are completely clamped, under the action of the driving force of the braking device, the bottle mouth part pushes the needle seat 31 to continuously move until the other end of the double-edged needle body punctures the needle protection cap and continuously moves, and the needle protection cap can be compressed, so that the needle protection cap is stacked in the process of continuously moving the needle seat 31 to enable one end, far away from the card type bottle 2, of the double-edged needle body to extend out, and finally injection is completed.

It is further noted that, in the present specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The injection pen provided by the utility model is described in detail above. The principles and embodiments of the present invention have been explained herein using specific examples, and the above descriptions of the embodiments are only used to help understand the method and its core ideas of the present invention. It should be noted that, for those skilled in the art, without departing from the principle of the present invention, the present invention can be further modified and modified, and such modifications and modifications also fall within the protection scope of the appended claims.

Claims

1. An injection pen, comprising:

The injection device comprises a shell (1), wherein a cartridge bottle medicine needle assembly and a brake device for driving the cartridge bottle medicine needle assembly to move towards the injection direction are arranged in the shell (1);

A safety cap (4) arranged at one end of the shell (1) and used for preventing the brake device from being triggered by mistake;

A trigger needle shield (5) which is used for colliding with an injection position during injection to trigger the brake device and hiding the injection needle (3) of the cartridge bottle medicine needle assembly after injection, wherein the trigger needle shield (5) is sleeved between the shell (1) and the brake device, and an elastic piece (6) which is used for driving the trigger needle shield (5) to move to hide the injection needle (3) after injection is arranged between the trigger needle shield (5) and the shell (1); the trigger needle shield (5) is clamped with the braking device before injection so as to prevent the trigger needle shield (5) from being ejected by the elastic piece (6) before injection; the trigger needle shield (5) is capable of being disengaged from the detent during movement of the cartridge vial needle assembly.

2. the injection pen according to claim 1, wherein the brake device comprises a cassette bottle holder (71) which is sleeved in the trigger needle shield (5) and is used for accommodating the cassette bottle medicine needle assembly, the inner wall of the trigger needle shield (5) is circumferentially provided with at least one first inward convex buckle (51), and the side wall of the cassette bottle holder (71) is provided with:

the clamping grooves (711) are used for being clamped with the first buckles (51) in a one-to-one corresponding mode;

The elastic first elastic sheet (712) is suspended in the clamping groove (711), the first elastic sheet (712) can be radially swung into the clamping bottle support (71) under the extrusion of the first buckle (51), and the clamping bottle medicine needle assembly can be radially swung out of the clamping bottle support (71) when moving to the clamping groove (711), so that the first buckle (51) is separated from the clamping groove (711).

3. The injection pen as claimed in claim 2, wherein the free end of the first resilient tab (712) is provided with a protrusion (713) for facilitating the disengagement of the first latch (51) from the slot (711), and the protrusion (713) protrudes from the inner wall of the cartridge holder (71).

4. The injection pen of any one of claims 1-3, further comprising:

The self-locking mechanism is arranged between the trigger needle shield (5) and the shell (1) and used for preventing the trigger needle shield (5) from retreating after the trigger needle shield (5) conceals the injection needle (3).

5. The injection pen of claim 4, wherein the self-locking mechanism comprises:

the trigger needle cover comprises at least one second buckle (53) arranged on the outer periphery of the trigger needle cover (5), the second buckle (53) is provided with a clamping groove used for being clamped with the end part of the shell (1), the second buckle (53) has elasticity, and can be radially inwards contracted under the extrusion of the end part of the shell (1) so that the end part of the shell (1) can be finally matched and clamped with the clamping groove.

6. The injection pen according to claim 5, wherein the trigger needle shield (5) is provided at its outer circumference with a relief groove (52) corresponding to the second catch (53) in one-to-one correspondence, and the second catch (53) comprises:

The second elastic sheet is connected with the first groove wall of the abdicating groove (52) and obliquely protrudes out of the notch of the abdicating groove (52), the clamping groove is arranged at one end, far away from the first groove wall, of the second elastic sheet, the clamping groove is connected with the second groove wall of the abdicating groove (52), and the second groove wall is opposite to the first groove wall; the second elastic sheet can contract towards the inside of the yielding groove (52) under the extrusion of the end part of the shell (1), and can restore elastic deformation when the extrusion force of the end part of the shell (1) is relieved, so that the end part of the shell (1) is clamped into the clamping groove.

7. The injection pen according to claim 4, wherein the cartridge vial and needle assembly comprises a cartridge (2) and an injection needle (3), the cartridge (2) and the injection needle (3) being provided independently of each other in the housing (1).

8. Injection pen according to claim 7, characterized in that the injection needle (3) comprises:

A needle seat (31) and a double-edge needle body arranged on the needle seat (31);

The sealing membrane is arranged at one end of the needle seat (31) facing the bottle opening part of the cassette bottle (2) and is used for sealing one end of the double-edge needle body;

And the needle protection cap is connected with the other end of the needle seat (31) and sleeved on the exposed peripheral part of the other end of the double-blade needle body, and the needle protection cap can be compressed.