CN114055793A - An automatic injection pen, an assembly fixture assembly and an automatic injection pen assembly method - Google Patents

Abstract

The embodiment of the application discloses automatic injection pen, assembly jig subassembly and automatic injection pen assembly method, and the embodiment of the application includes: the pen comprises a pen body and a pen container, a push-injection piston, a locking buckle, a locking hook, a first spring and a second spring; in the assembling process, the locking buckle can move to the locking position from the unlocking position under the action of the first spring and stably stay at the locking position, the situation that the locking buckle automatically leaves the locking position to cause the piston buckle and the lock hook to break away from and cause assembly failure when the piston is injected in the assembly is prevented, and the assembly success rate is improved.

Description

An automatic injection pen, an assembly fixture assembly and an automatic injection pen assembly method

technical field

The embodiments of the present application relate to the field of medical devices, and in particular, to an automatic injection pen, an assembly fixture assembly, and an assembly method for an automatic injection pen

Background technique

Automatic injection pens are widely used in the medical field. The automatic injection pen is easy to operate, and the patient can complete the injection independently without the help of medical staff. It is mainly used to meet the needs of the patient to complete the drug injection independently at home.

The existing automatic injection pen includes: pen body and pen holder, pen body and back cover, injection piston, locking buckle, locking hook and time spring. A push-injection piston, a locking buckle, a locking hook and a time spring are arranged in the pen body and pen holder, and a pen body back cover is arranged at the rear end of the pen body and pen holder. The back cover of the pen body fixes the lock hook at the rear end of the pen body and pen holder. After the installation is completed, the back cover of the pen body, the lock hook and the pen body and pen holder are relatively stationary. When the existing automatic injection pen is not used from the factory, the locking hook and the piston buckle at one end of the injection piston are engaged, and the locking buckle is used to fasten the piston buckle to ensure stable engagement. The time spring is in a retracted state, and one end is connected to the pusher. The other end of the injection piston is connected to the protrusion on the inner wall of the rear end of the pen barrel. When the existing automatic injection pen is triggered, the locking buckle moves toward the rear end of the pen body and the pen barrel relative to the locking hook, and the locking buckle leaves the piston buckle at one end of the injection piston. Under the pressure of the time spring on the bolus piston, the piston snap at one end of the bolus piston disengages from the lock hook, and the bolus piston moves to the front end of the pen barrel.

When assembling the existing automatic injection pen, it is necessary to first assemble the locking hook, the injection piston and the locking buckle outside the pen body and the pen barrel into a stable engagement state, and then assemble the time spring and the lock in the stable engagement state. The hook, the injection piston and the locking buckle are pushed into the pen body and pen holder from the front end of the pen body pen holder, and finally the pen body back cover is installed at the rear end of the pen body pen holder. Since the locking buckle can freely move relative to the locking hook to the rear end of the pen barrel, the locking buckle is easily separated from the piston buckle at one end of the injection piston when assembling the injection piston, resulting in the piston buckle at one end of the injection piston being released from the lock. Hook and the assembly fails, and the assembly failure rate is high.

SUMMARY OF THE INVENTION

The embodiments of the present application provide an automatic injection pen, an assembly fixture assembly, and an automatic injection pen assembly method, which are used to improve the assembly success rate of the automatic injection pen.

A first aspect of the embodiments of the present application provides an automatic injection pen, including: a pen body and a barrel, a bolus piston, a locking buckle, a locking hook, a first spring and a second spring;

The injection piston, the locking buckle, the lock hook, the first spring and the second spring are installed in the pen barrel, the lock hook is fixedly installed at the rear end of the pen barrel, the rear end of the first spring and the rear end of the second spring It is fixed relative to the pen body and the pen holder;

The rear end of the bolus piston is provided with a piston buckle, the piston buckle matches the lock hook, the lock buckle can move forward and backward relative to the lock hook, the lock buckle moves forward relative to the lock hook to reach the locking position, and the lock buckle is opposite to the lock hook. Move backward to the unlocking position, when the locking buckle is at the locking position, the piston buckle and the locking hook can be tightened, and when the locking buckle is at the unlocking position, the piston buckle and the locking hook can be released;

The rear end of the locking buckle is connected to the front end of the first spring. When the locking buckle is in the unlocking position, the first spring is in a compressed state, and when the locking buckle is in the locking position, the first spring is in a compressed state or a natural state;

The rear end of the bolus piston is connected to the front end of the second spring, and the second spring is in a compressed state when the piston snap is matched with the lock hook.

In a possible implementation manner of the first aspect of the embodiment of the present application, the rear end of the locking buckle is provided with a spring positioning portion, and the front end of the first spring cooperates with the spring positioning portion.

In a possible implementation manner of the first aspect of the embodiment of the present application, the spring positioning portion is a spring groove, and the front end of the first spring is installed in the spring groove.

In a possible implementation manner of the first aspect of the embodiment of the present application, a locking groove is provided inside the locking buckle, and the locking groove cooperates with the piston buckle or the locking hook.

In a possible implementation manner of the first aspect of the embodiment of the present application, the automatic injection pen further includes a refill holder and a syringe;

The refill holder is fixedly installed relative to the pen body and the pen holder;

The syringe is arranged in the refill holder;

The rear end of the refill holder is provided with a first buckle, the first buckle protrudes inwardly to contact the rear end of the needle cylinder, and the first buckle is used to prevent the needle cylinder from moving backward relative to the refill holder.

In a possible implementation manner of the first aspect of the embodiment of the present application, the front end of the refill holder is provided with a first protrusion, the first protrusion protrudes inwardly and contacts with the front end side wall of the syringe, and the first protrusion is used to limit the needle The barrel moves radially relative to the refill holder.

In a possible implementation manner of the first aspect of the embodiment of the present application, the automatic injection pen further includes a cap, a needle cap and a needle;

The needle is arranged at the front end of the syringe;

The needle cap covers the needle, and the rear end of the needle cap is matched with the front end of the needle barrel;

The cap covers the needle cap, and the rear end of the cap is matched with the front end of the refill holder;

The rear end of the cap is provided with a second buckle, and the second buckle protrudes inwardly and contacts the rear end of the needle cap;

The second buckle is used for when the cap moves forward relative to the refill holder, the needle cap moves forward relative to the refill holder together with the cap under the action of the second buckle, so that the cap is separated from the refill holder at the same time that the needle cap moves forward relative to the refill holder. The cap comes out of the barrel.

In a possible implementation manner of the first aspect of the embodiment of the present application, the automatic injection pen further includes a needle guard;

The rear end of the needle guard is provided with a third buckle, the front end of the locking buckle is provided with a fourth buckle, and the third buckle is matched with the fourth buckle.

In a possible implementation manner of the first aspect of the embodiment of the present application, the automatic injection pen further includes a third spring;

The needle guard is matched with the refill holder;

A third spring is arranged between the needle guard and the refill holder, and the needle guard can move back and forth relative to the refill holder;

When the needle guard moves forward to the limit position, the third spring is in a natural state or a compressed state;

When the needle guard moves backward to the limit position, the third spring is in a compressed state;

In a possible implementation manner of the first aspect of the embodiment of the present application, the automatic injection pen further includes an explosion-proof cover;

The explosion-proof sleeve is arranged at the rear end of the syringe.

In a possible implementation manner of the first aspect of the embodiments of the present application, the piston snap is a female snap, and the lock hook is provided with a male snap; or,

The piston buckle is a male buckle, and the lock hook is provided with a female buckle.

In a possible implementation manner of the first aspect of the embodiment of the present application, the automatic injection pen further includes that a window is provided on the side wall of the pen body and the pen holder.

A second aspect of the embodiments of the present application provides an assembly jig assembly for assembling the automatic injection pen of the first aspect, including: a first assembly jig, and the first assembly jig includes a push rod and a push cylinder;

The push rod can be inserted into the push cylinder, and the push rod and the push cylinder can move relatively;

The push rod is used to push the locking catch and the push cylinder is used to push the bolus piston.

In a possible implementation manner of the second aspect of the embodiment of the present application, a first orientation portion is provided on the rear end side wall of the push cylinder, and the first orientation portion cooperates with the injection piston to prevent the injection piston from rotating.

In a possible implementation manner of the second aspect of the embodiment of the present application, a second orientation portion is provided on the rear end side wall of the push rod, and the second orientation portion cooperates with the locking buckle to prevent the locking buckle from rotating.

In a possible implementation manner of the second aspect of the embodiment of the present application, the rear end of the push rod is provided with a blind hole, and the depth of the blind hole is greater than the first preset value, so that when the push rod pushes the locking buckle to the unlocked position, the The rod does not interfere with the piston rod of the bolus piston.

In a possible implementation manner of the second aspect of the embodiment of the present application, a limit block is provided at the front end of the push rod, and the limit block is used to limit the movement of the push cylinder, so that the push cylinder can be inserted from the rear end of the push rod until the push cylinder The movement of the relative push rod is stopped when it touches the limit block.

In a possible implementation manner of the second aspect of the embodiment of the present application, the assembly jig assembly further includes: a second assembly jig;

The second assembly jig includes a base and a raised portion;

The protruding portion is arranged at the front end of the base; the length of the protruding portion in the front-rear direction is greater than the second preset value, so that the protruding portion can fix the locking buckle in the locking position.

A third aspect of the embodiments of the present application provides a method for assembling an automatic injection pen, using the assembly jig assembly of the second aspect to assemble the automatic injection pen of the first aspect, including:

Fix the lock hook on the rear end of the pen barrel;

Place the second spring at the rear end of the bolus piston;

Place the first spring at the rear end of the locking buckle;

Place the locking catch on the rear end of the bolus piston;

The push rod of the first assembly jig pushes the locking buckle to the rear end of the pen barrel and the pen barrel, until the push rod pushes the locking button to the unlocking position. sports;

The push cylinder of the first assembly jig pushes the injection piston to move towards the rear end of the pen body and pen cylinder until the piston snaps and the lock hook cooperates, and the second spring moves to the rear end of the pen body pen cylinder under the thrust of the injection piston;

Move the push rod to the front end, and the locking buckle moves to the front end under the force of the first spring, until the locking buckle reaches the locking position, so that the locking buckle wraps the piston buckle and the locking hook;

After the locking buckle covers the piston buckle and the locking hook, withdraw the push rod and push barrel from the front end of the pen body and barrel.

In a possible implementation manner of the third aspect of the embodiment of the present application, before the push cylinder of the first assembly jig pushes the injection piston to move toward the rear end of the pen body and pen cylinder, the method further includes:

The first oriented portion of the push barrel is mated with the bolus piston.

In a possible implementation manner of the third aspect of the embodiment of the present application, before the push rod of the first assembly jig pushes the locking buckle to move toward the rear end of the pen barrel, the method further includes:

Engage the second directional portion of the push rod with the locking catch.

In a possible implementation manner of the third aspect of the embodiment of the present application, before the push cylinder of the first assembly jig pushes the injection piston to move toward the rear end of the pen body and pen cylinder, the method further includes:

Put the push cylinder into the push rod until the front end of the push cylinder abuts the limit block of the push rod, so that the push cylinder and the push rod move synchronously to the rear end of the pen barrel.

In a possible implementation manner of the third aspect of the embodiment of the present application, placing the first spring at the rear end of the locking buckle includes:

Fit the front end of the first spring with the spring positioning portion.

In a possible implementation manner of the third aspect of the embodiment of the present application, cooperating the front end of the first spring with the spring positioning portion includes:

Install the front end of the first spring in the spring groove.

In a possible implementation manner of the third aspect of the embodiment of the present application, after withdrawing the push rod and the push barrel from the front end of the pen body and the pen barrel, the method further includes:

Insert the second assembling jig from the rear end of the pen body and barrel, so that the protrusion of the second assembling jig abuts the rear end of the locking buckle, so that the locking buckle is stationary relative to the pen body and barrel;

Push the needle guard from the front end of the pen barrel until the needle guard and the locking buckle are locked together;

Pull out the second assembly jig from the rear end of the pen barrel.

In a possible implementation manner of the third aspect of the embodiment of the present application, before the needle guard is pushed in from the front end of the pen body and barrel, the method further includes:

Install the syringe in the refill holder;

Match the needle guard with the refill holder;

Before pulling out the second assembly jig from the rear end of the pen body and pen holder, the method further includes:

Push the refill holder from the front of the pen barrel until the refill holder and the barrel are locked together.

In a possible implementation manner of the third aspect of the embodiment of the present application, before installing the syringe in the refill holder, the method further includes:

Set the explosion-proof sleeve on the rear end of the syringe.

As can be seen from the above technical solutions, the embodiments of the present application have the following advantages:

The embodiment of the present application is provided with a first spring, so that the locking buckle can move from the unlocking position to the locking position under the action of the first spring and stay in the locking position stably, so as to prevent the locking buckle from automatically leaving when the bolus piston is assembled The locking position leads to the disengagement of the piston buckle and the lock hook, and the assembly fails, which improves the success rate of assembly.

Description of drawings

1 is an overall cross-sectional view of an automatic injection pen according to an embodiment of the present application;

2 is another overall cross-sectional view of an automatic injection pen according to an embodiment of the present application;

3 is a perspective view of a locking buckle of an automatic injection pen according to an embodiment of the present application;

4 is another perspective view of a locking buckle of an automatic injection pen according to an embodiment of the present application;

Fig. 5 is a side view of a locking buckle of an automatic injection pen according to an embodiment of the present application;

FIG. 6 is an A-A cross-sectional view of a locking buckle of an automatic injection pen according to an embodiment of the present application;

FIG. 7 is a front view of a locking buckle of an automatic injection pen according to an embodiment of the present application;

8 is a top view of a locking buckle of an automatic injection pen according to an embodiment of the present application;

9 is a perspective view of a refill holder of an automatic injection pen according to an embodiment of the present application;

10 is a top view of a refill holder for an automatic injection pen according to an embodiment of the present application;

11 is an assembly cross-sectional view of a refill holder and a prefilled syringe of an automatic injection pen according to an embodiment of the present application;

12 is a perspective view of a cap of an automatic injection pen according to an embodiment of the present application;

13 is a cross-sectional view of a cap of an automatic injection pen according to an embodiment of the present application;

Fig. 14 is an exploded view of the whole of an automatic injection pen and an assembly jig assembly according to an embodiment of the present application;

15 is an exploded view of the first assembly jig and its assembly structure of an automatic injection pen and an assembly jig assembly according to an embodiment of the present application;

16 is a perspective view of a first assembly jig and its assembly structure of an automatic injection pen and an assembly jig assembly according to an embodiment of the present application;

17 is a cross-sectional view of a first assembly jig and its assembly structure of an automatic injection pen and an assembly jig assembly according to an embodiment of the present application;

18 is an exploded view of the second assembly jig and its assembly structure of an automatic injection pen and an assembly jig assembly according to an embodiment of the present application;

19 is a perspective view of a second assembly jig and its assembly structure of an automatic injection pen and an assembly jig assembly according to an embodiment of the present application;

20 is a cross-sectional view of a second assembly jig and its assembly structure of an automatic injection pen and an assembly jig assembly according to an embodiment of the present application;

21 is a front view of a first assembly jig of an assembly jig assembly according to an embodiment of the present application;

22 is a front view of a second assembly jig of an assembly jig assembly according to an embodiment of the present application;

Fig. 23 is a flow chart of a method for assembling an automatic injection pen according to an embodiment of the present application;

Fig. 24 is another flowchart of a method for assembling an automatic injection pen according to an embodiment of the present application;

1. Pen body and pen holder; 101. The first snap hole; 102, Window; 2. Cap; 201, Second snap; 3. Refill holder; 301, First snap; 302, Fifth snap; 303 , the first protrusion; 4, the needle guard; 401, the third buckle; 5, the injection piston; 501, the piston buckle; 6, the locking buckle; 601, the fourth buckle; 602, the locking groove; 603, spring groove; 7, back cover of pen body; 8, locking hook; 9, explosion-proof cover; 10, second spring; 11, third spring; 12, first spring; 13, prefilled syringe; 1301, syringe ; 1302, needle; 1303, needle cap; 14, the first assembly jig; 1401, push rod; 1402, push cylinder; 1403, the first orientation part; 1404, blind hole; 15, the second assembly jig; 1501 , the base; 1502, the raised part.

Detailed ways

The embodiments of the present application provide an automatic injection pen, an assembly fixture assembly, and an assembly method for the automatic injection pen, which are used to improve the success rate of assembly.

When assembling the automatic injection pen, the automatic triggering device needs to be assembled in a locked state, so the locking hook 8 needs to be matched with the piston buckle 501 and the locking buckle 6 needs to be fastened. Since the locking buckle 6 can move back and forth relative to the locking hook 8, the locking buckle 6 has a locking position and an unlocking position, the locking hook 8 and the piston buckle 501 that have been engaged in the locking position cannot be separated, and the locking hooks 8 and The piston snap 501 also cannot be matched; the locking hook 8 and the piston snap 501 that are separated from each other in the unlocked position can cooperate under the action of external force, and the mutually matched locking hook 8 and the piston snap 501 can be separated under the action of external force.

Therefore, the assembly process is divided into three major steps. The first step is to push the locking buckle 6 to the unlocked position; the second step is to keep the locking buckle 6 in the unlocked position, and under the action of external force, the locking hook 8 and the piston are locked. The buckle 501 is matched; in the third step, the locking hook 8 and the piston buckle 501 are kept in cooperation, and the locking buckle 6 is moved from the unlocking position to the locking position.

As shown in FIGS. 1 to 20 , an automatic injection pen according to an embodiment of the present application includes: a pen barrel 1 , a bolus piston 5 , a locking buckle 6 , a locking hook 8 , a first spring 12 and a second spring 10 .

The bolus piston 5, the locking buckle 6, the locking hook 8, the first spring 12 and the second spring 10 are installed in the pen barrel 1, and the locking hook 8 is fixedly installed at the rear end of the pen barrel 1. The rear end and the rear end of the second spring 10 are fixed relative to the pen barrel 1 .

The rear end of the bolus piston 5 is provided with a piston buckle 501. The piston buckle 501 matches the locking hook 8. The locking buckle 6 can move back and forth relative to the locking hook 8, and the locking buckle 6 moves forward relative to the locking hook 8 to reach the locking position. , the locking buckle 6 moves backward relative to the locking hook 8 to reach the unlocking position. When the locking buckle 6 is in the locking position, it can tighten the piston buckle 501 and the locking hook 8. When the locking buckle 6 is in the unlocking position, it can release the piston buckle 501 and shackle 8.

The rear end of the locking buckle 6 is connected to the front end of the first spring 12. When the locking buckle 6 is in the unlocking position, the first spring 12 is in a compressed state, and when the locking buckle 6 is in the locking position, the first spring 12 is in a compressed state or state of nature.

The rear end of the bolus piston 5 is connected to the front end of the second spring 10 , and the second spring 10 is in a compressed state when the piston snap 501 is engaged with the lock hook 8 .

It should be noted that the front-rear direction in the embodiment of the present application is defined as follows, the direction from the locking hook 8 to the bolus piston 5 is the forward direction, and the direction from the bolus piston 5 to the lock hook 8 is the rearward direction. The front-rear direction may have other definitions, and the embodiments of the present application take the above definitions as an example.

In addition to the above trigger structure, the automatic injection pen in this embodiment also has a matching structure. The trigger structure and the matching structure are described below:

1. The trigger structure is further explained.

(1) Spring positioning part.

As shown in FIGS. 1 to 8 , the rear end of the locking buckle 6 is provided with a spring positioning portion, and the front end of the first spring 12 is matched with the spring positioning portion. The spring positioning portion is a spring groove 603 , and the front end of the first spring 12 is installed in the spring groove 603 . The outer diameter of the spring groove 603 is larger than the outer diameter of the first spring 12 , and the inner diameter of the spring groove 603 is smaller than the inner diameter of the first spring 12 groove 603 . The spring positioning portion may also be a protrusion or a buckle that cooperates with the first spring 12 , which is not specifically limited.

(2) The locking groove 602 .

As shown in FIGS. 3 to 8 , a locking groove 602 is provided inside the locking buckle 6 , and the locking groove 602 is matched with the piston buckle 501 or the locking hook 8 . The locking groove 602 extends in the front-rear direction, so that the locking buckle 6 can move back and forth relative to the locking hook 8 and move back and forth relative to the bolus piston 5 . The piston buckle 501 is a female buckle, and the lock hook 8 is provided with a male buckle. At this time, the locking groove 602 cooperates with the piston buckle 501; or, the piston buckle 501 is a male buckle, and the lock hook 8 is provided with a female buckle. When the locking groove 602 cooperates with the locking hook 8, this embodiment will be described with the former as an example. The matching manner of the piston buckle 501 and the lock hook 8 may also be a single-sided buckle.

The width of the locking groove 602 is greater than the width of the piston buckle 501 , so that the piston buckle 501 can be inserted into the locking groove 602 . The inner diameter of the locking buckle 6 at the locking groove 602 is larger than the outer diameter of the piston buckle 501 . During the fitting process of the piston snap 501 and the lock hook 8 , the piston snap 501 will undergo elastic deformation, and the maximum diameter reached by the piston snap 501 during the deformation process is called the maximum outer diameter of the fit. The inner diameter of the locking buckle 6 at the locking groove 602 is smaller than the maximum outer diameter of the piston buckle 501 . So that after the locking buckle 6 is fastened to the piston buckle 501 and the locking hook 8, the piston locking buckle 501 and the locking hook 8 cannot be separated.

Second, the supporting structure.

(1) Refill holder 3 and syringe 1301.

As shown in FIG. 1 to FIG. 2 and FIG. 9 to FIG. 11 , the embodiment of the present application further includes a refill holder 3 and a syringe 1301 .

The outer side of the refill holder 3 is provided with two fifth buckles 302 , the pen body and barrel 1 are provided with two first clamping holes 101 , and the fifth buckles 302 are matched with the first clamping holes 101 , so that the refill holder 3 is opposite to each other. The pen body and the pen holder 1 are fixedly installed. The refill holder 3 can also be fixedly mounted on the pen body and pen holder 1 in other ways, for example, a protrusion is provided in the pen body and pen holder 1 to restrict the movement of the pen refill holder 3, which is not specifically limited.

A syringe 1301 is provided in the refill holder 3 . The rear end of the refill holder 3 is provided with a first buckle 301 , the first buckle 301 protrudes inwardly and contacts the rear end of the syringe 1301 , and the first buckle 301 is used to prevent the syringe 1301 from being backward relative to the refill holder 3 move.

The front end of the refill holder 3 is provided with a first protrusion 303 , the first protrusion 303 protrudes inwardly and contacts the front end side wall of the syringe 1301 , and the first protrusion 303 is used to limit the radial direction of the syringe 1301 relative to the refill holder 3 . sports. There are two or more first protrusions 303 .

An explosion-proof sleeve 9 is installed at the rear end of the syringe 1301 to prevent the syringe 1301 from breaking.

(2) Cap 2 and needle cap 1303.

As shown in FIGS. 1 to 2 and 12 to 13 , the embodiment of the present application further includes a cap 2 , a needle cap 1303 and a needle 1302 .

The needle 1302 is provided at the front end of the needle barrel 1301 . The needle cap 1303 covers the needle head 1302 , and the rear end of the needle cap 1303 is matched with the front end of the needle barrel 1301 . The syringe 1301, the needle cap 1303 and the needle 1302 together constitute the pre-filled syringe 13, and the syringe 1301 contains the pre-filled medicinal liquid.

The rear end of the cap 2 is matched with the front end of the refill holder 3 , and the cap 2 is removably matched with the refill holder 3 , and then removably connected to the pen body and barrel 1 . The cap 2 can also be directly installed on the pen barrel 1 .

The cap 2 covers the needle cap 1303 , the rear end of the cap is provided with a second buckle 201 , and the second buckle 201 protrudes inward and contacts the rear end of the needle cap 1303 .

The second buckle 201 is used for when the cap 2 moves forward relative to the refill holder 3, the needle cap 1303 moves forward relative to the refill holder 3 together with the cap 2 under the action of the second buckle 201, so that the cap 2 When the refill holder 3 is released, the needle cap 1303 is released from the needle cylinder 1301. The second buckle 201 enables the user to pull out the syringe 1301 while pulling out the cap 2, thereby reducing user operations.

(3) Needle guard 4.

As shown in FIG. 1 to FIG. 2 and FIG. 14 , the embodiment of the present application further includes a needle guard 4 and a third spring 11 .

The needle guard 4 is matched with the refill holder 3 . A third spring 11 is arranged between the needle guard 4 and the refill holder 3 , and the needle guard 4 can move back and forth relative to the refill holder 3 .

The rear end of the needle guard 4 is provided with a third buckle 401 , and the front end of the locking buckle 6 is provided with a fourth buckle 601 , and the third buckle 401 is matched with the fourth buckle 601 . After the needle guard 4 and the locking buckle 6 are matched by the third buckle 401 and the fourth buckle 601 , the needle guard 4 and the locking buckle 6 move synchronously. When not injecting, the locking buckle 6 is in the locking position; when injecting, the user's skin contacts the needle guard 4 and pushes the needle guard 4 backward, and the needle guard 4 drives the locking buckle 6 to move backward to the unlocked position. The backward movement of the needle guard 4 causes the needle 1302 to emerge from the needle guard 4 and then penetrate the user's skin.

When the needle guard 4 moves forward to the limit position, the third spring 11 is in a natural state or a compressed state;

When the needle guard 4 moves backward to the limit position, the third spring 11 is in a compressed state; the third spring 11 is used to keep the needle guard 4 at the limit position of forward movement when the user is not using it.

It should be noted that the first spring 12 is also called an unlocking spring, the second spring 10 is also called a time spring, and the third spring 11 is also called a skin spring.

(4) Pen body and pen holder 1.

As shown in FIG. 1 to FIG. 2 and FIG. 14 , the embodiment of the present application further includes a pen body and a pen holder 1 .

The pen body and the pen holder 1 are tubular structures. A viewing window 102 is provided on the side wall of the pen body and the pen holder 1 . The window 102 may be hollow or transparent. The movement of the bolus piston 5 or the change of the pre-filled liquid medicine can be observed from the window 102, so that the user can know the progress of the injection. A pen body rear cover 7 is installed at the rear end of the pen body and pen holder 1 .

The material of the automatic injection pen and the parameters of different springs are explained below:

The material of the pen body and barrel 1 is PC; the material of the cap 2 is ABS; the material of the refill holder 3 is POM; the material of the needle guard 4 is POM; the material of the injection piston 5 is ABS; the material of the locking buckle 6 is The material of the back cover 7 of the pen body is ABS; the material of the lock hook 8 is POM; the material of the explosion-proof cover 9 is TPR.

The material of the first spring 12 is SUS 304, and the relevant parameters are: wire diameter 0.60, outer diameter 14, length 31.1, the total number of turns is 14, the effective number of turns is 10, left-handed, and the compression amount is 13mm.

The material of the second spring 10 is SUS 304, and the relevant parameters are: wire diameter 1.00, outer diameter 19.5, length 85.4, the total number of turns is 12, the effective number of turns is 8, left-handed, the maximum compression amount is 62mm, and the minimum compression amount is 22mm.

The material of the third spring 11 is SUS 304, and the relevant parameters are: wire diameter 0.70, outer diameter 12.8, length 33.4, the total number of turns is 9, the effective number of turns is 5, left-handed, and the compression amount is 9mm.

The above is just an example, the material of the automatic injection pen and the parameters of different springs can be adjusted according to actual needs.

As shown in FIGS. 14 to 22 , an embodiment of the present application provides an assembly jig assembly for assembling the automatic injection pen in the embodiment shown in FIGS. 1 to 20 , including: a first assembly jig 14 , The first assembly jig 14 includes a push rod 1401 and a push cylinder 1402 . The push rod 1401 can be inserted into the push cylinder 1402, and the push rod 1401 and the push cylinder 1402 can move relatively. The push rod 1401 is used to push the locking buckle 6 , and the push cylinder 1402 is used to push the injection piston 5 .

The assembly jig assembly of the embodiment of the present application may include a plurality of assembly jigs, which will be described separately below.

1. Further description of the first assembly jig 14 .

The first assembly jig 14 may also have a structure for cooperating with a specific mechanical arm or manipulator, such as a positioning part, a fixing part, etc., which is not specifically limited here.

A first orientation portion 1403 is provided on the rear end side wall of the push cylinder 1402 , and the first orientation portion 1403 cooperates with the injection piston 5 to prevent the injection piston 5 from rotating.

A second orientation portion may also be provided on the rear end side wall of the push rod 1401 , and the second orientation portion cooperates with the locking buckle 6 to prevent the locking buckle 6 from rotating. The first orientation portion 1403 and the second orientation portion determine the installation angle of the locking buckle 6 and the bolus piston 5 to prevent misalignment. It should be noted that only one of the first orientation portion 1403 and the second orientation portion can be used, that is, only the second orientation portion is provided on the rear end side wall of the push rod 1401 or only the rear end side wall of the push cylinder 1402 A first orientation portion 1403 is provided on the top of the push cylinder 1402 , and this embodiment is described by taking as an example that the first orientation portion 1403 is only provided on the rear end side wall of the push cylinder 1402 .

The first orientation portion 1403 may be a depression or a protrusion; the second orientation portion may be a depression or a protrusion. The first orientation parts 1403 may be arranged on both sides of the push cylinder 1402 ; the second orientation parts may be arranged at both sides of the push rod 1401 .

The rear end of the push rod 1401 is provided with a blind hole 1404, and the depth of the blind hole 1404 is greater than the first preset value, so that when the push rod 1401 pushes the locking buckle 6 to the unlocked position, the push rod 1401 and the piston rod of the injection piston 5 No interference occurs.

The front end of the push rod 1401 is provided with a limit block. The limit block is used to limit the movement of the push cylinder 1402, so that the push cylinder 1402 can be inserted from the rear end of the push rod 1401 until the push cylinder 1402 stops relative to the push rod when it contacts the limit block. 1401 Movement. The limit block enables the push rod 1401 and the push cylinder 1402 to move to the rear end synchronously, thereby pushing the locking buckle 6 and the bolus piston 5 to the rear end synchronously, so that when the locking buckle 6 reaches the unlocked position, the bolus piston 5 and The lock hook 8 cooperates.

2. The second assembly jig 15 .

The embodiment of the present application further includes: a second assembly jig 15 . The second assembly jig 15 includes a base 1501 and a protrusion 1502 .

The protruding portion 1502 is disposed at the front end of the base 1501; the length of the protruding portion 1502 in the front-rear direction is greater than the second preset value, so that the protruding portion 1502 can fix the locking buckle 6 in the locking position.

The second assembling jig 15 may also have a structure for cooperating with a specific mechanical arm or manipulator, such as a positioning part, a fixing part, etc., which is not specifically limited here.

As shown in FIG. 23 , an embodiment of the present application provides a method for assembling an automatic injection pen, using the jig assembly in the embodiment shown in FIG. 14 to FIG. Automatic injection pen for assembly. The assembly method can be performed using machinery or manually.

2301. Fix the lock hook 8 on the rear end of the pen barrel 1 of the pen body.

The lock hook 8 is inserted into the pen body and pen holder 1 from the rear end of the pen body and pen holder 1, and is fixedly installed.

2302 . Place the second spring 10 on the rear end of the bolus piston 5 .

The front end of the second spring 10 is in contact with the rear end of the bolus piston 5 .

2303 . Place the first spring 12 on the rear end of the locking buckle 6 .

The front end of the first spring 12 is in contact with the rear end of the locking buckle 6 .

2304 . Place the locking buckle 6 on the rear end of the bolus piston 5 .

The locking buckle 6 is located behind the bolus piston 5 , so that after the assembly is completed, the locking buckle 6 can move backward relative to the bolus piston 5 .

The timings of steps 2301 , 2302 , 2303 and 2304 are irrelevant and are not specifically limited.

2305. The push rod 1401 pushes the locking buckle 6 to move toward the rear end of the pen body and barrel 1.

The locking buckle 6 runs to the rear end until the push rod 1401 pushes the locking buckle 6 to the unlocking position, and the first spring 12 moves to the rear end of the pen barrel 1 under the pushing force of the locking buckle 6 . When the locking buckle 6 reaches the unlocking position, the first spring 12 is in a compressed state. At this time, the rear end of the first spring 12 contacts the pen barrel 1 , and the front end of the first spring 12 contacts the locking buckle 6 .

2306 , the push cylinder 1402 pushes the injection piston 5 to move toward the rear end of the pen body and the pen cylinder 1 .

The piston snap 501 moves to the rear end until the piston snap 501 cooperates with the lock hook 8 , and the second spring 10 moves to the rear end of the pen barrel 1 under the thrust of the push piston 5 . When the bolus piston 5 cooperates with the locking hook 8 , the second spring 10 is in a compressed state.

Steps 2305 and 2306 may be performed sequentially or simultaneously, which is not specifically limited.

2307. Move the push rod 1401 to the front end.

The push rod 1401 moves forward, so that the locking buckle 6 moves to the front end under the force of the first spring 12 until the locking buckle 6 reaches the locking position, so that the locking buckle 6 is tightened on the piston buckle 501 and the locking hook 8 .

2308. Exit the push rod 1401 and the push cylinder 1402 from the front end of the pen body and the pen holder 1.

After the locking buckle 6 is tightened on the piston buckle 501 and the locking hook 8 , the push rod 1401 and the push cylinder 1402 are withdrawn from the front end of the pen body and the pen holder 1 . The push rod 1401 and the push cylinder 1402 can be withdrawn sequentially or simultaneously, which is not specifically limited.

As shown in FIG. 24 , another method for assembling an automatic injection pen provided by an embodiment of the present application includes:

2401. Install the lock hook 8.

The lock hook 8 is inserted into the pen body and pen holder 1 from the rear end of the pen body and pen holder 1, and is fixedly installed.

2402 . Arrange the bolus piston 5 , the locking buckle 6 , the first spring 12 and the second spring 10 .

A second spring 10 is placed at the rear end of the bolus piston 5 . The front end of the second spring 10 is in contact with the rear end of the bolus piston 5 .

The first spring 12 is placed at the rear end of the locking buckle 6 . The front end of the first spring 12 is in contact with the rear end of the locking buckle 6 . The front end of the first spring 12 is matched with the spring positioning part, that is, the front end of the first spring 12 is installed in the spring groove 603 .

The locking catch 6 is placed on the rear end of the bolus piston 5 . The locking buckle 6 is located behind the bolus piston 5 , so that after the assembly is completed, the locking buckle 6 can move backward relative to the bolus piston 5 .

2403 . Arrange the first assembly jig 14 , the locking buckle 6 and the bolus piston 5 .

Put the push cylinder 1402 into the push rod 1401 until the front end of the push cylinder 1402 abuts the limit block of the push rod 1401, so that the push cylinder 1402 and the push rod 1401 move to the rear end of the pen barrel 1 synchronously.

The first orientation portion 1403 of the push cylinder 1402 is matched with the push injection piston 5 so that the push injection piston 5 cannot rotate relative to the push cylinder 1402 , and the installation angle of the push injection piston 5 is determined.

The second orientation portion of the push rod 1401 is matched with the locking buckle 6 so that the locking buckle 6 cannot rotate relative to the push rod 1401 , and the installation angle of the locking buckle 6 is determined.

2404. Push the locking buckle 6 to the unlocking position, and make the piston buckle 501 cooperate with the locking hook 8.

The push rod 1401 of the first assembly jig 14 pushes the locking buckle 6 to move toward the rear end of the pen barrel 1 . The locking buckle 6 runs to the rear end until the push rod 1401 pushes the locking buckle 6 to the unlocking position, and the first spring 12 moves to the rear end of the pen barrel 1 under the pushing force of the locking buckle 6 . When the locking buckle 6 reaches the unlocking position, the first spring 12 is in a compressed state. At this time, the rear end of the first spring 12 contacts the pen barrel 1 , and the front end of the first spring 12 contacts the locking buckle 6 .

The push cylinder 1402 of the first assembly jig 14 pushes the injection piston 5 to move toward the rear end of the pen barrel 1 . The piston snap 501 moves to the rear end until the piston snap 501 cooperates with the lock hook 8 , and the second spring 10 moves to the rear end of the pen barrel 1 under the thrust of the push piston 5 . When the bolus piston 5 cooperates with the locking hook 8 , the second spring 10 is in a compressed state.

2405. Push the locking buckle 6 to the locking position.

The push rod 1401 moves forward, so that the locking buckle 6 moves to the front end under the force of the first spring 12 until the locking buckle 6 reaches the locking position, so that the locking buckle 6 is tightened on the piston buckle 501 and the locking hook 8 .

2406. Exit the push rod 1401 and the push cylinder 1402.

After the locking buckle 6 is tightened on the piston buckle 501 and the locking hook 8 , the push rod 1401 and the push cylinder 1402 are withdrawn from the front end of the pen body and the pen holder 1 . The push rod 1401 and the push cylinder 1402 can be withdrawn sequentially or simultaneously, which is not specifically limited.

2407. Fix the locking buckle 6.

Insert the second assembling jig 15 from the rear end of the pen body and barrel 1, so that the protrusion 1502 of the second assembling jig 15 abuts the rear end of the locking buckle 6, so that the locking buckle 6 is stationary relative to the pen body and barrel 1 . The locking hook 8 is provided with a through hole, so that the protruding portion 1502 of the second assembling jig 15 can pass through the locking hook 8 and then abut against the locking buckle 6 .

2408. Match the needle guard 4 with the locking buckle 6.

The explosion-proof sleeve 9 is set at the rear end of the syringe 1301 . The syringe 1301 is installed in the refill holder 3 . Match the needle guard 4 with the refill holder 3 .

Push the needle guard 4 and the refill holder 3 from the front end of the pen barrel 1 until the needle guard 4 and the locking buckle 6 are locked together and the refill holder 3 and the pen barrel 1 are locked together.

2409. Exit the second assembly jig 15.

Pull out the second assembly jig 15 from the rear end of the pen barrel 1 . The back cover 7 of the pen body is installed on the rear end of the pen body and the pen holder 1 . Install the cap 2 on the front end of the pen barrel 1.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above may refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are only illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods, for example, multiple units or components may be combined or integrated. to another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

Units described as separate components may or may not be physically separated, and components shown as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

The integrated unit, if implemented as a software functional unit and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application can be embodied in the form of software products in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, and the computer software products are stored in a storage medium , including several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in the various embodiments of the present application. The aforementioned storage medium includes: U disk, removable hard disk, read-only memory (ROM, read-only memory), random access memory (RAM, random access memory), magnetic disk or optical disk and other media that can store program codes .

Claims (27)

1. An automatic injection pen, comprising: the pen body comprises a pen body pen container (1), a push injection piston (5), a locking buckle (6), a locking hook (8), a first spring (12) and a second spring (10);

the push-injection piston (5), the locking buckle (6), the locking hook (8), the first spring (12) and the second spring (10) are mounted in the pen body pen container (1), the locking hook (8) is fixedly mounted at the rear end of the pen body pen container (1), and the rear ends of the first spring (12) and the second spring (10) are fixed relative to the pen body pen container (1);

a piston buckle (501) is arranged at the rear end of the pushing piston (5), the piston buckle (501) is matched with the lock hook (8), the locking buckle (6) can move back and forth relative to the lock hook (8), the locking buckle (6) moves forward relative to the lock hook (8) to reach a locking position, the locking buckle (6) moves backward relative to the lock hook (8) to reach an unlocking position, the piston buckle (501) and the lock hook (8) can be tightly sleeved when the locking buckle (6) is located at the locking position, and the piston buckle (501) and the lock hook (8) can be released when the locking buckle (6) is located at the unlocking position;

the rear end of the locking buckle (6) is connected with the front end of the first spring (12), the first spring (12) is in a compressed state when the locking buckle (6) is located at an unlocking position, and the first spring (12) is in a compressed state or a natural state when the locking buckle (6) is located at a locking position;

the rear end of the pushing piston (5) is connected with the front end of the second spring (10), and the second spring (10) is in a compressed state when the piston buckle (501) is matched with the locking hook (8).

2. The autoinjector pen according to claim 1, wherein a rear end of the latch (6) is provided with a spring locating portion with which a front end of the first spring (12) cooperates.

3. The automatic injection pen of claim 2, wherein the spring positioning portion is a spring groove (603), and a front end of the first spring (12) is mounted in the spring groove (603).

4. Auto-injection pen according to any of claims 1 to 3, characterized in that the locking catch (6) is provided with a locking groove (602) inside, the locking groove (602) cooperating with the piston catch (501) or the locking hook (8).

5. The automatic injection pen of any of claims 1 to 3, further comprising a cartridge holder (3) and a syringe (1301);

the pen core frame (3) is fixedly arranged relative to the pen body and the pen container (1);

the needle cylinder (1301) is arranged in the refill holder (3);

the rear end of the refill holder (3) is provided with a first buckle (301), the first buckle (301) protrudes inwards to be in contact with the rear end of the needle cylinder (1301), and the first buckle (301) is used for preventing the needle cylinder (1301) from moving backwards relative to the refill holder (3).

6. The automatic injection pen of claim 5, wherein the cartridge holder (3) is provided at a front end thereof with a first projection (303), the first projection (303) projecting inwardly to be in contact with a front end side wall of the cylinder (1301), the first projection (303) serving to restrict the cylinder (1301) from moving radially relative to the cartridge holder (3).

7. The automatic injection pen of claim 5, further comprising a cap (2), a needle cap (1303) and a needle (1302);

the needle (1302) is arranged at the front end of the needle cylinder (1301);

the needle cap (1303) sleeves the needle (1302), and the rear end of the needle cap (1303) is matched with the front end of the needle cylinder (1301);

the needle cap (1303) is sleeved by the cap (2), and the rear end of the cap (2) is matched with the front end of the refill frame (3);

the rear end of the cap is provided with a second buckle (201), and the second buckle (201) protrudes inwards to be in contact with the rear end of the needle cap (1303);

the second buckle (201) is used for enabling the needle cap (1303) to move forwards relative to the refill holder (3) together with the cap (2) under the action of the second buckle (201) when the cap (2) moves forwards relative to the refill holder (3), so that the needle cap (1303) is separated from the needle cylinder (1301) while the cap (2) is separated from the refill holder (3).

8. The automatic injection pen of claim 5, further comprising a needle guard (4);

the rear end of the needle guard sleeve (4) is provided with a third buckle (401), the front end of the locking buckle (6) is provided with a fourth buckle (601), and the third buckle (401) is matched with the fourth buckle (601).

9. The automatic injection pen of claim 8, further comprising a third spring (11);

the needle guard sleeve (4) is matched with the pencil lead frame (3);

the third spring (11) is arranged between the needle guard sleeve (4) and the pen core frame (3), and the needle guard sleeve (4) can move back and forth relative to the pen core frame (3);

when the needle guard sleeve (4) moves forwards to the limit position, the third spring (11) is in a natural state or a compressed state;

when the needle guard sleeve (4) moves backwards to the limit position, the third spring (11) is in a compressed state.

10. The automatic injection pen of claim 5, further comprising an explosion-proof sleeve (9);

the explosion-proof sleeve (9) is arranged at the rear end of the needle cylinder (1301).

11. The automatic injection pen of any of claims 1 to 3 or 6 to 10,

the piston buckle (501) is a female buckle, and a male buckle is arranged on the lock hook (8); or,

the piston buckle (501) is a male buckle, and a female buckle is arranged on the lock hook (8).

12. The automatic injection pen of any of claims 1 to 3 or 6 to 10, further comprising a window (102) provided in a side wall of the pen body barrel (1).

13. An assembly jig assembly for assembling an automatic injection pen according to any one of claims 1 to 11, comprising: the first assembling jig (14), wherein the first assembling jig (14) comprises a push rod (1401) and a push cylinder (1402);

the push rod (1401) can be sleeved in the push cylinder (1402), and the push rod (1401) and the push cylinder (1402) can move relatively;

the push rod (1401) is used for pushing the locking buckle (6), and the push cylinder (1402) is used for pushing the push injection piston (5).

14. The assembly jig assembly according to claim 13, characterized in that a first orientation portion (1403) is provided on a rear end side wall of the push cylinder (1402), and the first orientation portion (1403) is engaged with the push plunger (5) for preventing the push plunger (5) from rotating.

15. The assembly jig assembly according to claim 13 or 14, characterized in that a second orientation portion is provided on a rear end side wall of the push rod (1401), and the second orientation portion is engaged with the locking buckle (6) for preventing the locking buckle (6) from rotating.

16. The assembly jig assembly according to claim 13 or 14, characterized in that a blind hole (1404) is formed in the rear end of the push rod (1401), and the depth of the blind hole (1404) is larger than a first preset value, so that when the push rod (1401) pushes the locking buckle (6) to the unlocking position, the push rod (1401) and a piston rod of the pushing and injecting piston (5) do not interfere with each other.

17. The assembly jig assembly according to claim 13 or 14, characterized in that the front end of the push rod (1401) is provided with a limiting block for limiting the movement of the push cylinder (1402), so that the push cylinder (1402) can be inserted from the rear end of the push rod (1401) until the push cylinder (1402) contacts the limiting block, and the movement of the push rod (1401) is stopped.

18. The assembly jig assembly as claimed in claim 13 or 14, further comprising: a second assembly jig (15);

the second assembly jig (15) comprises a base (1501) and a boss (1502);

the boss (1502) is arranged at the front end of the base (1501); the length of the protruding part (1502) in the front and back direction is larger than a second preset value, so that the protruding part (1502) can fix the locking buckle (6) at the locking position.

19. An automatic injection pen assembling method, characterized in that the automatic injection pen of any one of claims 1 to 12 is assembled by using the assembling jig assembly of any one of claims 13 to 18, comprising:

the lock hook (8) is fixedly arranged at the rear end of the pen body and pen container (1);

placing the second spring (10) at the rear end of the bolus piston (5);

-placing the first spring (12) at the rear end of the locking catch (6);

placing the locking buckle (6) at the rear end of the push injection piston (5);

the push rod (1401) of the first assembling jig (14) pushes the locking buckle (6) to move towards the rear end of the pen body barrel (1) until the push rod (1401) pushes the locking buckle (6) to reach the unlocking position, and the first spring (12) moves towards the rear end of the pen body barrel (1) under the action of the pushing force of the locking buckle (6);

the push cylinder (1402) of the first assembling jig (14) pushes the push-injection piston (5) to move towards the rear end of the pen body pen container (1) until the piston buckle (501) is matched with the locking hook (8), and the second spring (10) moves towards the rear end of the pen body pen container (1) under the thrust action of the push-injection piston (5);

moving the push rod (1401) to the front end, and moving the locking buckle (6) to the front end under the action of the first spring (12) until the locking buckle (6) reaches the locking position, so that the locking buckle (6) sleeves the piston buckle (501) and the locking hook (8);

after the locking buckle (6) is tightly sleeved on the piston buckle (501) and the locking hook (8), the push rod (1401) and the push cylinder (1402) are withdrawn from the front end of the pen body and pen container (1).

20. The auto-injector pen assembly method according to claim 19, characterized in that before the push rod (1401) of the first assembly fixture (14) pushes the locking catch (6) towards the rear end of the pen body barrel (1), the method further comprises:

-mating the second orientation of the push rod (1401) with the locking catch (6).

21. The auto-injector pen assembly method according to claim 19 or 20, characterized in that before the push cylinder (1402) of the first assembly fixture (14) pushes the bolus piston (5) towards the rear end of the pen body barrel (1), the method further comprises:

-mating the first orientation (1403) of the push cylinder (1402) with the bolus piston (5).

22. The auto-injector pen assembly method according to claim 19 or 20, characterized in that before the push cylinder (1402) of the first assembly fixture (14) pushes the bolus piston (5) towards the rear end of the pen body barrel (1), the method further comprises:

sleeving the push cylinder (1402) into the push rod (1401) until the front end of the push cylinder (1402) abuts against the limiting block of the push rod (1401), so that the push cylinder (1402) and the push rod (1401) synchronously move towards the rear end of the pen body pen container (1).

23. The auto-injection pen assembly method according to claim 19 or 20, wherein the placing of the first spring (12) at the rear end of the locking catch (6) comprises:

fitting the front end of the first spring (12) with the spring positioning portion.

24. The auto-injection pen assembly method of claim 23, wherein the engaging the front end of the first spring (12) with the spring positioning portion comprises:

mounting the front end of the first spring (12) in the spring groove (603).

25. The auto-injection pen assembly method according to claim 19 or 20, wherein after said withdrawing the plunger (1401) and the pusher (1402) from the front end of the pen body barrel (1), the method further comprises:

inserting a second assembling jig (15) from the rear end of the pen body pen container (1) to enable a protruding part (1502) of the second assembling jig (15) to abut against the rear end of the locking buckle (6) to enable the locking buckle (6) to be static relative to the pen body pen container (1);

pushing a needle protecting sleeve (4) into the pen body barrel (1) from the front end thereof until the needle protecting sleeve (4) and the locking buckle (6) are clamped with each other;

and pulling out the second assembling jig (15) from the rear end of the pen body pen container (1).

26. The auto-injection pen assembly method according to claim 24, wherein before the pushing the needle guard sleeve (4) in from the front end of the pen body barrel (1), the method further comprises:

installing a syringe (1301) in the refill holder (3);

the needle guard sleeve (4) is matched with the pencil lead frame (3);

before the second assembling jig (15) is pulled out from the rear end of the pen body pen container (1), the method further comprises the following steps:

and pushing the pen core frame (3) into the pen body and pen container (1) from the front end of the pen body and pen container (1) until the pen core frame (3) and the pen body and pen container (1) are mutually clamped.

27. The auto-injection pen assembly method of claim 25, wherein prior to the installing the syringe (1301) within the cartridge holder (3), the method further comprises:

and arranging the explosion-proof sleeve (9) at the rear end of the needle cylinder (1301).

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