Automatic injection pen, assembly jig assembly and automatic injection pen assembly method

Abstract

The embodiment of the present application discloses an automatic injection pen, an assembly jig assembly and an automatic injection pen assembly method. The embodiment of the present application includes: a pen body, a pen barrel, a push piston, a locking buckle, a locking hook, a first spring and a second spring; during the assembly process, the locking buckle can move from an unlocked position to a locked position under the action of the first spring and stay stably in the locked position, preventing the locking buckle from automatically leaving the locked position when assembling the push piston, causing the piston buckle and the locking hook to disengage and the assembly failure, thereby improving the assembly success rate.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and more particularly to an automatic injection pen, an assembly fixture assembly, and an automatic injection pen assembly method. Background Art

[0002] Automatic injection pens are widely used in the medical field. Automatic injection pens are easy to operate, and patients can complete the injection independently without the help of medical staff. They are mainly used to meet the needs of patients to complete drug injections at home.

[0003] The existing automatic injection pen comprises: a pen body and a pen barrel, a pen body back cover, a push injection piston, a locking buckle, a locking hook and a time spring. The push injection piston, the locking buckle, the locking hook and the time spring are arranged in the pen body and the pen barrel, and the pen body back cover is arranged at the rear end of the pen body and the pen barrel. The pen body back cover fixes the locking hook at the rear end of the pen body and the pen barrel. After the installation is completed, the pen body back cover, the locking hook and the pen body and the pen barrel are relatively static. When the existing automatic injection pen is not used after leaving the factory, the locking hook and the piston buckle at one end of the push injection piston are engaged, and the locking buckle is used to tighten the piston buckle to ensure the stability of the engagement. The time spring is in a contracted state, one end is connected to the push injection piston, and the other end is connected to the protrusion of the inner wall at the rear end of the pen body and 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 push injection piston. Under the pressure of the time spring on the push injection piston, the piston buckle at one end of the push injection piston is separated from the locking hook, and the push injection piston moves toward the front end of the pen body and the pen barrel.

[0004] When assembling an existing automatic injection pen, it is necessary to first assemble the lock hook, the injection piston and the locking buckle outside the pen body and pen barrel into a stable engaging state, then push the time spring and the lock hook, the injection piston and the locking buckle in the stable engaging state into the pen body and pen barrel from the front end of the pen body and pen barrel, and finally install the pen body rear cover at the rear end of the pen body and pen barrel. Since the locking buckle can freely move toward the rear end of the pen body and pen barrel relative to the lock hook, when assembling the injection piston, the lock buckle is easy to leave the piston buckle at one end of the injection piston, resulting in the piston buckle at one end of the injection piston being separated from the lock hook and the assembly failure, and the assembly failure rate is high. Summary of the invention

[0005] The embodiments of the present application provide an automatic injection pen, an assembly jig assembly, and an automatic injection pen assembly method, which are used to improve the assembly success rate of the automatic injection pen.

[0006] A first aspect of an embodiment of the present application provides an automatic injection pen, comprising: a pen body and a pen barrel, a push piston, a locking buckle, a locking hook, a first spring and a second spring;

[0007] The injection piston, the locking buckle, the locking hook, the first spring and the second spring are installed in the pen body and pen barrel, the locking hook is fixedly installed at the rear end of the pen body and pen barrel, and the rear ends of the first spring and the second spring are fixed relative to the pen body and pen barrel;

[0008] A piston buckle is provided at the rear end of the push piston, and the piston buckle matches the locking hook. The locking buckle can move forward and backward relative to the locking hook. The locking buckle moves forward relative to the locking hook to reach the locking position, and the locking buckle moves backward relative to the locking hook to reach the unlocking position. When the locking buckle is in the locking position, the piston buckle and the locking hook can be tightly covered, and when the locking buckle is in the unlocking position, the piston buckle and the locking hook can be released;

[0009] 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. When the locking buckle is in the locking position, the first spring is in a compressed state or a natural state.

[0010] The rear end of the push piston is connected to the front end of the second spring, and the second spring is in a compressed state when the piston buckle is engaged with the locking hook.

[0011] In a possible implementation of the first aspect of the embodiment of the present application, a spring positioning portion is provided at the rear end of the locking buckle, and the front end of the first spring cooperates with the spring positioning portion.

[0012] In a possible implementation 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.

[0013] In a possible implementation 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.

[0014] In a possible implementation of the first aspect of the embodiment of the present application, the automatic injection pen further includes a cartridge holder and a syringe;

[0015] The pen core holder is fixedly installed relative to the pen body and pen barrel;

[0016] The syringe is arranged in the refill frame;

[0017] A first buckle is arranged at the rear end of the pen core frame. The first buckle protrudes inwards and contacts with the rear end of the syringe. The first buckle is used to prevent the syringe from moving backward relative to the pen core frame.

[0018] In a possible implementation of the first aspect of the embodiment of the present application, a first protrusion is provided at the front end of the refill frame, the first protrusion protrudes inwardly and contacts the front end side wall of the syringe, and the first protrusion is used to limit the radial movement of the syringe relative to the refill frame.

[0019] In a possible implementation 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;

[0020] The needle is arranged at the front end of the syringe;

[0021] The needle cap covers the needle, and the rear end of the needle cap cooperates with the front end of the syringe;

[0022] The cap covers the needle cap, and the rear end of the cap matches the front end of the pen core frame;

[0023] A second buckle is provided at the rear end of the cap, and the second buckle protrudes inwardly to contact with the rear end of the needle cap;

[0024] The second buckle is used for the needle cap to move forward relative to the refill frame together with the cap when the cap moves forward relative to the refill frame under the action of the second buckle, so that the cap is separated from the refill frame and the needle cap is separated from the syringe at the same time.

[0025] In a possible implementation of the first aspect of the embodiment of the present application, the automatic injection pen further includes a needle guard;

[0026] The rear end of the needle guard is provided with a third buckle, and the front end of the locking buckle is provided with a fourth buckle, and the third buckle and the fourth buckle cooperate with each other.

[0027] In a possible implementation of the first aspect of the embodiment of the present application, the automatic injection pen further includes a third spring;

[0028] The needle guard cooperates with the refill holder;

[0029] A third spring is arranged between the needle guard and the refill frame, so that the needle guard can move forward and backward relative to the refill frame;

[0030] When the needle guard moves forward to the limit position, the third spring is in a natural state or a compressed state;

[0031] When the needle guard moves backward to the extreme position, the third spring is in a compressed state;

[0032] In a possible implementation of the first aspect of the embodiment of the present application, the automatic injection pen further includes an explosion-proof sleeve;

[0033] The explosion-proof sleeve is arranged at the rear end of the syringe.

[0034] In a possible implementation of the first aspect of the embodiment of the present application, the piston buckle is a female buckle, and the lock hook is provided with a male buckle; or,

[0035] The piston buckle is a male buckle, and the lock hook is provided with a female buckle.

[0036] In a possible implementation of the first aspect of the embodiment of the present application, the automatic injection pen further includes a side wall of the pen body and pen barrel being provided with a viewing window.

[0037] 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, comprising: a first assembly jig, the first assembly jig comprising a push rod and a push cylinder;

[0038] The push rod can be inserted into the push cylinder, and the push rod and the push cylinder can move relative to each other;

[0039] The push rod is used to push the locking buckle, and the push cylinder is used to push the injection piston.

[0040] In a possible implementation 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 push piston to prevent the push piston from rotating.

[0041] In a possible implementation 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.

[0042] In a possible implementation of the second aspect of the embodiment of the present application, a blind hole is provided at the rear end of the push rod, and the depth of the blind hole is greater than a first preset value, so that when the push rod pushes the locking buckle to the unlocking position, the push rod and the piston rod of the injection piston do not interfere with each other.

[0043] In a possible implementation 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 contacts the limit block and stops moving relative to the push rod.

[0044] 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;

[0045] The second assembly jig includes a base and a protrusion;

[0046] The protrusion is arranged at the front end of the base; the length of the protrusion in the front-to-back direction is greater than a second preset value, so that the protrusion can fix the locking buckle in the locking position.

[0047] A third aspect of the embodiment of the present application provides an automatic injection pen assembly method, using the assembly jig assembly of the second aspect to assemble the automatic injection pen of the first aspect, comprising:

[0048] The lock hook is fixedly installed on the rear end of the pen body and pen barrel;

[0049] placing a second spring at the rear end of the push piston;

[0050] Placing the first spring at the rear end of the locking buckle;

[0051] Place the locking buckle on the rear end of the injection piston;

[0052] The push rod of the first assembly fixture pushes the locking buckle to move toward the rear end of the pen body and pen barrel until the push rod pushes the locking buckle to the unlocking position, and the first spring moves toward the rear end of the pen body and pen barrel under the thrust of the locking buckle;

[0053] The push cylinder of the first assembly fixture pushes the injection piston to move toward the rear end of the pen body and pen barrel until the piston buckle and the lock hook cooperate, and the second spring moves toward the rear end of the pen body and pen barrel under the thrust of the injection piston;

[0054] Move the push rod to the front end, and the locking buckle moves to the front end under the action of the first spring until the locking buckle reaches the locking position, so that the locking buckle tightly covers the piston buckle and the locking hook;

[0055] After the locking buckle is tightly fitted onto the piston buckle and the locking hook, the push rod and the push cylinder are withdrawn from the front end of the pen body and the pen cylinder.

[0056] In a possible implementation of the third aspect of the embodiment of the present application, before the push cylinder of the first assembly fixture pushes the push piston to move toward the rear end of the pen body and pen cylinder, the method further includes:

[0057] The first directional portion of the push cylinder is engaged with the push piston.

[0058] In a possible implementation of the third aspect of the embodiment of the present application, before the push rod of the first assembly fixture pushes the locking buckle to move toward the rear end of the pen body and pen holder, the method further includes:

[0059] The second directional portion of the push rod is engaged with the locking buckle.

[0060] In a possible implementation of the third aspect of the embodiment of the present application, before the push cylinder of the first assembly fixture pushes the push piston to move toward the rear end of the pen body and pen cylinder, the method further includes:

[0061] The push tube is inserted into the push rod until the front end of the push tube abuts against the limit block of the push rod, so that the push tube and the push rod move synchronously toward the rear end of the pen body and pen barrel.

[0062] In a possible implementation of the third aspect of the embodiment of the present application, placing the first spring at the rear end of the locking buckle includes:

[0063] The front end of the first spring is engaged with the spring positioning portion.

[0064] In a possible implementation of the third aspect of the embodiment of the present application, matching the front end of the first spring with the spring positioning portion includes:

[0065] Install the front end of the first spring in the spring groove.

[0066] In a possible implementation of the third aspect of the embodiment of the present application, after the push rod and the push tube are withdrawn from the front end of the pen body and the pen tube, the method further includes:

[0067] Insert the second assembly jig from the rear end of the pen body and pen barrel, so that the raised portion of the second assembly jig abuts against the rear end of the locking buckle, so that the locking buckle is stationary relative to the pen body and pen barrel;

[0068] Push the needle guard into the pen body from the front end until the needle guard and the locking buckle are locked together;

[0069] Pull out the second assembly fixture from the rear end of the pen body and pen barrel.

[0070] In a possible implementation of the third aspect of the embodiment of the present application, before the needle guard is pushed into the pen body and pen barrel from the front end, the method further includes:

[0071] Install the syringe into the refill holder;

[0072] Match the needle guard with the refill holder;

[0073] Before pulling out the second assembly fixture from the rear end of the pen body and pen holder, the method further includes:

[0074] Push the refill holder into the pen body from the front end of the pen barrel until the refill holder and the pen barrel are locked together.

[0075] In a possible implementation of the third aspect of the embodiment of the present application, before the syringe is installed in the refill holder, the method further includes:

[0076] The explosion-proof sleeve is arranged at the rear end of the syringe.

[0077] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0078] 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 and stay stably in the locking position under the action of the first spring, preventing the locking buckle from automatically leaving the locking position when assembling the push piston, causing the piston buckle and the locking hook to disengage and the assembly failure, thereby improving the assembly success rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 An overall cross-sectional view of an automatic injection pen according to an embodiment of the present application;

[0080] Figure 2 Another overall cross-sectional view of an automatic injection pen according to an embodiment of the present application;

[0081] Figure 3 A three-dimensional diagram of a locking buckle of an automatic injection pen according to an embodiment of the present application;

[0082] Figure 4 Another stereoscopic view of a locking buckle of an automatic injection pen according to an embodiment of the present application;

[0083] Figure 5 A side view of a locking buckle of an automatic injection pen according to an embodiment of the present application;

[0084] Figure 6 An AA cross-sectional view of a locking buckle of an automatic injection pen according to an embodiment of the present application;

[0085] Figure 7 A front view of a locking buckle of an automatic injection pen according to an embodiment of the present application;

[0086] Figure 8 A top view of a locking buckle of an automatic injection pen according to an embodiment of the present application;

[0087] Fig. 9 A three-dimensional diagram of a cartridge holder of an automatic injection pen according to an embodiment of the present application;

[0088] Fig.10 A top view of a cartridge holder of an automatic injection pen according to an embodiment of the present application;

[0089] Fig.11 An assembly cross-sectional view of a cartridge holder and a prefilled syringe of an automatic injection pen according to an embodiment of the present application;

[0090] Fig.12 A three-dimensional diagram of a cap of an automatic injection pen according to an embodiment of the present application;

[0091] Fig.13 A cross-sectional view of a cap of an automatic injection pen according to an embodiment of the present application;

[0092] Fig.14 An exploded view of an automatic injection pen and an assembly fixture assembly according to an embodiment of the present application;

[0093] Fig.15 An exploded view of an automatic injection pen and a first assembly jig of an assembly jig assembly and its assembly structure according to an embodiment of the present application;

[0094] Fig.16 A stereoscopic diagram of an automatic injection pen and a first assembly jig of an assembly jig assembly and its assembly structure according to an embodiment of the present application;

[0095] Fig.17 A cross-sectional view of an automatic injection pen and a first assembly jig of an assembly jig assembly and its assembly structure according to an embodiment of the present application;

[0096] Fig.18 An exploded view of an automatic injection pen and a second assembly jig of an assembly jig assembly and its assembly structure according to an embodiment of the present application;

[0097] Fig.19 A stereoscopic diagram of an automatic injection pen and a second assembly jig of an assembly jig assembly and its assembly structure according to an embodiment of the present application;

[0098] Fig. 20 A cross-sectional view of an automatic injection pen and a second assembly jig of an assembly jig assembly and its assembly structure according to an embodiment of the present application;

[0099] Fig.21A front view of a first assembly jig of an assembly jig assembly according to an embodiment of the present application;

[0100] Fig. 22 A front view of a second assembly jig of an assembly jig assembly according to an embodiment of the present application;

[0101] Fig.23 A flow chart of an automatic injection pen assembly method according to an embodiment of the present application;

[0102] Fig.24 Another flow chart of an automatic injection pen assembly method according to an embodiment of the present application;

[0103] 1. Pen body and pen holder; 101. First clamp hole; 102. Window; 2. Cap; 201. Second clamp; 3. Pen core holder; 301. First clamp; 302. Fifth clamp; 303. First protrusion; 4. Needle guard; 401. Third clamp; 5. Push piston; 501. Piston clamp; 6. Locking buckle; 601. Fourth clamp; 602. Locking groove; 603. Spring groove; 7. Pen body cover; 8 , locking hook; 9, explosion-proof sleeve; 10, second spring; 11, third spring; 12, first spring; 13, prefilled syringe; 1301, syringe; 1302, needle; 1303, needle cap; 14, first assembly fixture; 1401, push rod; 1402, push cylinder; 1403, first directional portion; 1404, blind hole; 15, second assembly fixture; 1501, base; 1502, raised portion. DETAILED DESCRIPTION

[0104] Embodiments of the present application provide an automatic injection pen, an assembly jig assembly, and an automatic injection pen assembly method, which are used to improve the success rate of assembly.

[0105] When assembling the automatic injection pen, the automatic trigger device needs to be assembled into a locked state, so the lock hook 8 and the piston buckle 501 need to be matched and tightened with the lock buckle 6. Since the lock buckle 6 can move forward and backward relative to the lock hook 8, the lock buckle 6 has a locked position and an unlocked position. The lock hook 8 and the piston buckle 501 that have been matched in the locked position cannot be separated, and the lock hook 8 and the piston buckle 501 that are separated from each other cannot be matched; the lock hook 8 and the piston buckle 501 that are separated from each other in the unlocked position can be matched under the action of external force, and the lock hook 8 and the piston buckle 501 that are matched with each other can be separated under the action of external force.

[0106] 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 match the locking hook 8 and the piston buckle 501 under the action of external force; the third step is to keep the locking hook 8 and the piston buckle 501 matched, and move the locking buckle 6 from the unlocked position to the locked position.

[0107] like Figures 1 to 20 As shown, an automatic injection pen according to an embodiment of the present application includes: a pen body and pen barrel 1, a push piston 5, a locking buckle 6, a locking hook 8, a first spring 12 and a second spring 10.

[0108] The push piston 5, the locking buckle 6, the locking hook 8, the first spring 12 and the second spring 10 are installed in the pen body and pen barrel 1, the locking hook 8 is fixedly installed at the rear end of the pen body and pen barrel 1, and the rear ends of the first spring 12 and the rear ends of the second spring 10 are fixed relative to the pen body and pen barrel 1.

[0109] A piston buckle 501 is provided at the rear end of the push piston 5, and the piston buckle 501 matches the locking hook 8. The locking buckle 6 can move forward and backward relative to the locking hook 8. The locking buckle 6 moves forward relative to the locking hook 8 to reach the locking position, and 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, and when the locking buckle 6 is in the unlocking position, it can release the piston buckle 501 and the locking hook 8.

[0110] 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 located at the unlocking position, the first spring 12 is in a compressed state. When the locking buckle 6 is located at the locking position, the first spring 12 is in a compressed state or a natural state.

[0111] The rear end of the push piston 5 is connected to the front end of the second spring 10 , and when the piston buckle 501 is matched with the locking hook 8 , the second spring 10 is in a compressed state.

[0112] It should be noted that the front and rear directions in the embodiment of the present application are defined as follows: the direction from the lock hook 8 to the injection piston 5 is the forward direction, and the direction from the injection piston 5 to the lock hook 8 is the backward direction. The front and rear directions may have other definitions, and the embodiment of the present application takes the above definition as an example.

[0113] In addition to the trigger structure described above, the automatic injection pen in this embodiment also has a supporting structure. The trigger structure and the supporting structure are described below:

[0114] 1. Further explanation of the trigger structure.

[0115] (1) Spring positioning portion.

[0116] like Figures 1 to 8 As shown, the rear end of the locking buckle 6 is provided with a spring positioning portion, and the front end of the first spring 12 cooperates 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 groove 603 of the first spring 12. The spring positioning portion can also be a protrusion or a buckle that cooperates with the first spring 12, which is not specifically limited.

[0117] (2) Locking groove 602.

[0118] like Figures 3 to 8 As shown, a locking groove 602 is provided inside the locking buckle 6, and the locking groove 602 cooperates with the piston buckle 501 or the lock hook 8. The locking groove 602 extends in the front-to-back direction, so that the locking buckle 6 can move forward and backward relative to the lock hook 8 and move forward and backward relative to the injection piston 5. The piston buckle 501 is a female buckle, and the lock hook 8 is provided with a male buckle. In this case, 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. In this case, the locking groove 602 cooperates with the lock hook 8. This embodiment is described by taking the former as an example. The cooperation mode between the piston buckle 501 and the lock hook 8 can also be a single-sided buckle.

[0119] 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 embedded in the locking groove 602. The inner diameter of the locking buckle 6 at the locking groove 602 is greater than the outer diameter of the piston buckle 501. During the matching process of the piston buckle 501 and the locking hook 8, the piston buckle 501 will undergo elastic deformation, and the maximum diameter reached by the piston buckle 501 during the deformation process is called the maximum matching outer diameter. The inner diameter of the locking buckle 6 at the locking groove 602 is smaller than the maximum matching outer diameter of the piston buckle 501. After the locking buckle 6 is tightly sleeved on the piston buckle 501 and the locking hook 8, the piston buckle 501 and the locking hook 8 cannot be separated.

[0120] 2. Supporting structure.

[0121] (1) Pen core holder 3 and syringe 1301.

[0122] like Figure 1 to Figure 2 and Figures 9 to 11 As shown, the embodiment of the present application also includes a refill rack 3 and a syringe 1301 .

[0123] Two fifth buckles 302 are arranged on the outer side of the refill frame 3, and two first buckle holes 101 are arranged on the pen body and pen barrel 1. The fifth buckles 302 cooperate with the first buckle holes 101, so that the refill frame 3 is fixedly installed relative to the pen body and pen barrel 1. The refill frame 3 can also be fixedly installed on the pen body and pen barrel 1 in other ways, such as providing a protrusion in the pen body and pen barrel 1 to limit the movement of the refill frame 3, which is not specifically limited.

[0124] The syringe 1301 is arranged in the refill frame 3. The rear end of the refill frame 3 is provided with a first buckle 301, which protrudes inwards and contacts with the rear end of the syringe 1301, and is used to prevent the syringe 1301 from moving backward relative to the refill frame 3.

[0125] The front end of the refill holder 3 is provided with a first protrusion 303, which protrudes inwards and contacts the front end side wall of the syringe 1301, and is used to limit the radial movement of the syringe 1301 relative to the refill holder 3. There are two or more first protrusions 303.

[0126] An explosion-proof sleeve 9 is installed at the rear end of the syringe 1301 to prevent the syringe 1301 from rupturing.

[0127] (2) Cap 2 and needle cap 1303.

[0128] like Figure 1 to Figure 2 and Figure 12 to Figure 13 As shown, the embodiment of the present application also includes a cap 2, a needle cap 1303 and a needle 1302.

[0129] The needle 1302 is arranged at the front end of the syringe 1301. The needle cap 1303 covers the needle 1302, and the rear end of the needle cap 1303 cooperates with the front end of the syringe 1301. The syringe 1301, the needle cap 1303 and the needle 1302 together constitute the prefilled syringe 13, and the syringe 1301 contains the prefilled liquid medicine.

[0130] The rear end of the cap 2 is matched with the front end of the pen core frame 3, and the cap 2 is detachably matched with the pen core frame 3, and then detachably connected with the pen body and pen container 1. The cap 2 can also be directly installed on the pen body and pen container 1.

[0131] The cap 2 covers the needle cap 1303 , and a second buckle 201 is provided at the rear end of the cap 2 . The second buckle 201 protrudes inwardly and contacts with the rear end of the needle cap 1303 .

[0132] The second buckle 201 is used for the needle cap 1303 to move forward relative to the refill frame 3 together with the cap 2 under the action of the second buckle 201 when the cap 2 moves forward relative to the refill frame 3, so that the cap 2 is separated from the refill frame 3 and the needle cap 1303 is separated from the syringe 1301. The second buckle 201 allows the user to remove the syringe 1301 at the same time as removing the cap 2, reducing the user's operation.

[0133] (3) Needle guard 4.

[0134] like Figure 1 to Figure 2 and Fig.14 As shown, the embodiment of the present application also includes a needle guard 4 and a third spring 11.

[0135] The needle guard 4 cooperates with the refill frame 3. A third spring 11 is arranged between the needle guard 4 and the refill frame 3, and the needle guard 4 can move forward and backward relative to the refill frame 3.

[0136] 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 and the fourth buckle 601 cooperate. After the needle guard 4 and the locking buckle 6 cooperate through the third buckle 401 and the fourth buckle 601, the needle guard 4 and the locking buckle 6 move synchronously. When not injected, the locking buckle 6 is in the locked position; when injected, 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 needle guard 4 moves backward so that the needle head 1302 is exposed from the needle guard 4, and then pierces the user's skin.

[0137] When the needle guard 4 moves forward to the limit position, the third spring 11 is in a natural state or a compressed state;

[0138] When the needle guard 4 moves backward to the extreme position, the third spring 11 is in a compressed state; the third spring 11 is used to keep the needle guard 4 in the extreme position of forward movement when the user is not using it.

[0139] 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.

[0140] (4) Pen body and pen holder 1.

[0141] like Figure 1 to Figure 2 and Fig.14 As shown, the embodiment of the present application also includes a pen body and a pen holder 1.

[0142] The pen body and pen barrel 1 is a tubular structure. The side wall of the pen body and pen barrel 1 is provided with a viewing window 102. The viewing window 102 can be hollow or made of a transparent material. The movement of the push piston 5 or the change of the pre-filled liquid can be observed through the viewing window 102, so that the user can know the progress of the injection. The rear end of the pen body and pen barrel 1 is provided with a pen body rear cover 7.

[0143] The following is a description of the materials and parameters of different springs of the automatic injection pen:

[0144] The material of the pen body and pen barrel 1 is PC; the material of the cap 2 is ABS; the material of the refill frame 3 is POM; the material of the needle guard 4 is POM; the material of the push piston 5 is ABS; the material of the locking buckle 6 is POM; the material of the pen body rear cover 7 is ABS; the material of the locking hook 8 is POM; the material of the explosion-proof sleeve 9 is TPR.

[0145] 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, total number of turns 14, effective number of turns 10, left-handed, and compression amount 13mm.

[0146] 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, total number of turns 12, effective number of turns 8, left-handed, maximum compression 62mm, minimum compression 22mm.

[0147] 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, total number of turns 9, effective number of turns 5, left-handed, and compression amount 9mm.

[0148] The above are only examples, and the material of the automatic injection pen and the parameters of different springs can be adjusted according to actual needs.

[0149] like Figures 14 to 22 As shown, the embodiment of the present application provides an assembly fixture assembly for assembling Figures 1 to 20 The automatic injection pen in the illustrated embodiment includes: a first assembly fixture 14, which 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 relative to each other. 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.

[0150] The assembly jig assembly of the embodiment of the present application may include multiple assembly jigs, which are described below respectively.

[0151] 1. Further description of the first assembly jig 14 .

[0152] The first assembly fixture 14 may also have a structure for cooperating with a specific robot arm or robot hand, such as a positioning portion, a fixing portion, etc., which is not specifically limited here.

[0153] 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 push piston 5 to prevent the push piston 5 from rotating.

[0154] 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 injection piston 5 to prevent misalignment. It should be noted that only one of the first orientation portion 1403 and the second orientation portion may 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 first orientation portion 1403 is provided on the rear end side wall of the push cylinder 1402. This embodiment is described by taking the example of only providing the first orientation portion 1403 on the rear end side wall of the push cylinder 1402.

[0155] 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 portion 1403 may be disposed on both sides of the push cylinder 1402; the second orientation portion may be disposed on both sides of the push rod 1401.

[0156] A blind hole 1404 is provided at the rear end of the push rod 1401 , and the depth of the blind hole 1404 is greater 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 the piston rod of the injection piston 5 do not interfere with each other.

[0157] A limit block is provided at the front end of the push rod 1401, and 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 contacts the limit block and stops moving relative to the push rod 1401. The limit block allows the push rod 1401 and the push cylinder 1402 to move toward the rear end synchronously, thereby pushing the locking buckle 6 and the injection piston 5 toward the rear end synchronously, so that when the locking buckle 6 reaches the unlocking position, the injection piston 5 and the locking hook 8 cooperate.

[0158] 2. The second assembly jig 15.

[0159] The embodiment of the present application further includes: a second assembly fixture 15. The second assembly fixture 15 includes a base 1501 and a protrusion 1502.

[0160] The protrusion 1502 is disposed at the front end of the base 1501 ; the length of the protrusion 1502 in the front-to-back direction is greater than a second preset value, so that the protrusion 1502 can fix the locking buckle 6 in the locking position.

[0161] The second assembly fixture 15 may also have a structure for cooperating with a specific robot arm or robot hand, such as a positioning portion, a fixing portion, etc., which is not specifically limited here.

[0162] like Fig.23 As shown, the embodiment of the present application provides an automatic injection pen assembly method, using Figures 14 to 22 The assembly jig assembly in the embodiment shown is Figures 1 to 20 The automatic injection pen in the illustrated embodiment is assembled. The assembly method can be performed mechanically or manually.

[0163] 2301. Fix the lock hook 8 on the rear end of the pen body and pen holder 1.

[0164] The locking hook 8 is inserted into the pen body and pen barrel 1 from the rear end of the pen body and pen barrel 1 and fixedly installed.

[0165] 2302. Place the second spring 10 at the rear end of the push piston 5.

[0166] The front end of the second spring 10 contacts the rear end of the push piston 5 .

[0167] 2303. Place the first spring 12 at the rear end of the locking buckle 6.

[0168] The front end of the first spring 12 contacts the rear end of the locking buckle 6 .

[0169] 2304. Place the locking buckle 6 at the rear end of the push piston 5.

[0170] The locking buckle 6 is located behind the push piston 5 so that after assembly, the locking buckle 6 can move backward relative to the push piston 5 .

[0171] The timing of steps 2301, 2302, 2303 and 2304 is irrelevant and is not specifically limited.

[0172] 2305. The push rod 1401 pushes the locking buckle 6 to move toward the rear end of the pen body and pen holder 1.

[0173] The locking buckle 6 moves 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 body and pen barrel 1 under the thrust of the locking buckle 6. When the locking buckle 6 reaches the unlocking position, the first spring 12 is in a compressed state, at which time the rear end of the first spring 12 contacts the pen body and pen barrel 1, and the front end of the first spring 12 contacts the locking buckle 6.

[0174] 2306. The push cylinder 1402 pushes the injection piston 5 to move toward the rear end of the pen body and pen cylinder 1.

[0175] The piston buckle 501 moves toward the rear end until the piston buckle 501 and the lock hook 8 are matched, and the second spring 10 moves toward the rear end of the pen body and pen barrel 1 under the thrust of the injection piston 5. When the injection piston 5 and the lock hook 8 are matched, the second spring 10 is in a compressed state, at which time the rear end of the second spring 10 contacts the pen body and pen barrel 1, and the front end of the second spring 10 contacts the injection piston 5.

[0176] Steps 2305 and 2306 may be performed sequentially or simultaneously, and are not specifically limited.

[0177] 2307. Move the push rod 1401 toward the front end.

[0178] The push rod 1401 moves forward, causing the locking buckle 6 to move toward 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 is tightly sleeved on the piston buckle 501 and the locking hook 8.

[0179] 2308. Remove the push rod 1401 and the push tube 1402 from the front end of the pen body and pen tube 1.

[0180] 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 tube 1402 are withdrawn from the front end of the pen body and pen tube 1. The push rod 1401 and the push tube 1402 can be withdrawn in sequence or at the same time, which is not specifically limited.

[0181] like Fig.24 As shown, another automatic injection pen assembly method provided in an embodiment of the present application includes:

[0182] 2401. Install the locking hook 8.

[0183] The locking hook 8 is inserted into the pen body and pen barrel 1 from the rear end of the pen body and pen barrel 1 and fixedly installed.

[0184] 2402. Arrange the push piston 5, the locking buckle 6, the first spring 12 and the second spring 10.

[0185] The second spring 10 is placed at the rear end of the push piston 5. The front end of the second spring 10 is in contact with the rear end of the push piston 5.

[0186] The first spring 12 is placed at the rear end of the locking buckle 6. The front end of the first spring 12 contacts the rear end of the locking buckle 6. The front end of the first spring 12 is matched with the spring positioning portion, that is, the front end of the first spring 12 is installed in the spring groove 603.

[0187] The locking buckle 6 is placed at the rear end of the push piston 5. The locking buckle 6 is located at the rear of the push piston 5 so that after assembly, the locking buckle 6 can move backward relative to the push piston 5.

[0188] 2403. Arrange the first assembly fixture 14, the locking buckle 6 and the injection piston 5.

[0189] The push tube 1402 is inserted into the push rod 1401 until the front end of the push tube 1402 abuts against the limit block of the push rod 1401, so that the push tube 1402 and the push rod 1401 move synchronously toward the rear end of the pen body and pen holder 1.

[0190] The first orientation portion 1403 of the push cylinder 1402 is matched with the push piston 5 so that the push piston 5 cannot rotate relative to the push cylinder 1402 , thereby determining the installation angle of the push piston 5 .

[0191] 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, thereby determining the installation angle of the locking buckle 6.

[0192] 2404. Push the locking buckle 6 to the unlocking position, and make the piston buckle 501 cooperate with the locking hook 8.

[0193] The push rod 1401 of the first assembly jig 14 pushes the locking buckle 6 to move toward the rear end of the pen body and pen barrel 1. The locking buckle 6 moves toward the rear end until the push rod 1401 pushes the locking buckle 6 to the unlocked position, and the first spring 12 moves toward the rear end of the pen body and pen barrel 1 under the thrust of the locking buckle 6. When the locking buckle 6 reaches the unlocked position, the first spring 12 is in a compressed state, at which time the rear end of the first spring 12 contacts the pen body and pen barrel 1, and the front end of the first spring 12 contacts the locking buckle 6.

[0194] The push cylinder 1402 of the first assembly jig 14 pushes the injection piston 5 to move toward the rear end of the pen body and pen barrel 1. The piston buckle 501 moves toward the rear end until the piston buckle 501 and the lock hook 8 are matched, and the second spring 10 moves toward the rear end of the pen body and pen barrel 1 under the thrust of the injection piston 5. When the injection piston 5 and the lock hook 8 are matched, the second spring 10 is in a compressed state, at which time the rear end of the second spring 10 contacts the pen body and pen barrel 1, and the front end of the second spring 10 contacts the injection piston 5.

[0195] 2405. Push the locking buckle 6 to the locking position.

[0196] The push rod 1401 moves forward, causing the locking buckle 6 to move toward 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 is tightly sleeved on the piston buckle 501 and the locking hook 8.

[0197] 2406. Exit the push rod 1401 and the push cylinder 1402.

[0198] 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 tube 1402 are withdrawn from the front end of the pen body and pen tube 1. The push rod 1401 and the push tube 1402 can be withdrawn in sequence or at the same time, which is not specifically limited.

[0199] 2407. Fix the locking buckle 6.

[0200] The second assembly jig 15 is inserted from the rear end of the pen body and pen barrel 1, so that the protrusion 1502 of the second assembly jig 15 abuts against the rear end of the locking buckle 6, so that the locking buckle 6 is stationary relative to the pen body and pen barrel 1. A through hole is provided in the locking hook 8, so that the protrusion 1502 of the second assembly jig 15 can pass through the locking hook 8 and then abut against the locking buckle 6.

[0201] 2408. Match the needle guard 4 with the locking buckle 6.

[0202] The explosion-proof cover 9 is arranged at the rear end of the syringe 1301. The syringe 1301 is installed in the core frame 3. The needle guard cover 4 is matched with the core frame 3.

[0203] Push the needle guard 4 and the refill holder 3 into the front end of the pen body and pen barrel 1 until the needle guard 4 and the locking buckle 6 are locked together and the refill holder 3 and the pen body and pen barrel 1 are locked together.

[0204] 2409. Exit the second assembly fixture 15.

[0205] The second assembly fixture 15 is pulled out from the rear end of the pen body and pen container 1. The pen body rear cover 7 is installed at the rear end of the pen body and pen container 1. The cap 2 is installed at the front end of the pen body and pen container 1.

[0206] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0207] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0208] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0209] 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 separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0210] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, read-only memory), random access memory (RAM, random access memory), disk or optical disk, etc. Various media that can store program codes.

Claims

1. An automatic injection pen, characterized in that: include: A pen body and a pen barrel (1), a push piston (5), a locking buckle (6), a locking hook (8), a first spring (12) and a second spring (10); The push piston (5), the locking buckle (6), the locking hook (8), the first spring (12) and the second spring (10) are installed in the pen body and pen barrel (1), the locking hook (8) is fixedly installed at the rear end of the pen body and pen barrel (1), and the rear ends of the first spring (12) and the second spring (10) are fixed relative to the pen body and pen barrel (1); A piston buckle (501) is arranged at the rear end of the push piston (5), the piston buckle (501) matches the locking hook (8), the locking buckle (6) can move forward and backward relative to the locking hook (8), the locking buckle (6) moves forward relative to the locking hook (8) to reach a locking position, and the locking buckle (6) moves backward relative to the locking hook (8) to reach an unlocking position, when the locking buckle (6) is in the locking position, it can tighten the piston buckle (501) and the locking hook (8), and when the locking buckle (6) is in the unlocking position, it can release the piston buckle (501) and the locking hook (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; when the locking buckle (6) is in the locking position, the first spring (12) is in a compressed state or a natural state; The rear end of the injection piston (5) is connected to the front end of the second spring (10), and when the piston buckle (501) is engaged with the locking hook (8), the second spring (10) is in a compressed state; The direction from the locking hook (8) to the pushing piston (5) is the forward direction, and the direction from the pushing piston (5) to the locking hook (8) is the backward direction.

2. The automatic injection pen according to claim 1, characterized in that: A spring positioning portion is provided at the rear end of the locking buckle (6), and the front end of the first spring (12) cooperates with the spring positioning portion.

3. The automatic injection pen according to claim 2, characterized in that: 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).

4. The automatic injection pen according to any one of claims 1 to 3, characterized in that: The locking buckle (6) is provided with a locking groove (602) inside, and the locking groove (602) cooperates with the piston buckle (501) or the locking hook (8).

5. The automatic injection pen according to any one of claims 1 to 3, characterized in that: Also includes a refill holder (3) and a syringe (1301); The pen core frame (3) is fixedly mounted relative to the pen body and pen holder (1); The syringe (1301) is arranged in the pen core frame (3); The rear end of the refill frame (3) is provided with a first buckle (301), the first buckle (301) protrudes inwards and contacts the rear end of the syringe (1301), and the first buckle (301) is used to prevent the syringe (1301) from moving backward relative to the refill frame (3).

6. The automatic injection pen according to claim 5, characterized in that: The front end of the pen core holder (3) is provided with a first protrusion (303), which protrudes inwards and contacts the front end side wall of the syringe (1301), and the first protrusion (303) is used to limit the radial movement of the syringe (1301) relative to the pen core holder (3).

7. The automatic injection pen according to claim 5, characterized in that: Also includes a cap (2), a needle cap (1303) and a needle (1302); The needle (1302) is arranged at the front end of the syringe (1301); The needle cap (1303) covers the needle head (1302), and the rear end of the needle cap (1303) cooperates with the front end of the syringe (1301); The cap (2) covers the needle cap (1303), and the rear end of the cap (2) cooperates with the front end of the pen core holder (3); A second buckle (201) is provided at the rear end of the cap (2), and the second buckle (201) protrudes inwards to contact the rear end of the needle cap (1303); The second buckle (201) is used for moving the needle cap (1303) forward relative to the pen core frame (3) together with the cap (2) under the action of the second buckle (201) when the cap (2) moves forward relative to the pen core frame (3), so that the cap (2) is separated from the pen core frame (3) and the needle cap (1303) is separated from the syringe (1301) at the same time.

8. The automatic injection pen according to claim 5, characterized in that: Also includes a needle guard (4); The rear end of the needle guard (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) and the fourth buckle (601) cooperate with each other.

9. The automatic injection pen according to claim 8, characterized in that: Also included is a third spring (11); The needle guard (4) cooperates with the pen core frame (3); The third spring (11) is arranged between the needle guard (4) and the pen core frame (3), and the needle guard (4) can move forward and backward relative to the pen core frame (3); 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 extreme position, the third spring (11) is in a compressed state.

10. The automatic injection pen according to claim 5, characterized in that: Also includes, an explosion-proof sleeve (9); The explosion-proof sleeve (9) is arranged at the rear end of the syringe (1301).

11. The automatic injection pen according to any one of claims 1 to 3 or 6 to 10, characterized in that: The piston buckle (501) is a female buckle, and the locking hook (8) is provided with a male buckle; or, The piston buckle (501) is a male buckle, and the locking hook (8) is provided with a female buckle.

12. The automatic injection pen according to any one of claims 1 to 3 or 6 to 10, characterized in that: It also includes that a side wall of the pen body and pen holder (1) is provided with a viewing window (102).

13. An assembly jig assembly, characterized in that: Used for assembling the automatic injection pen according to any one of claims 1 to 11, comprising: a first assembly jig (14), the first assembly jig (14) comprising 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 relative to each other; 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).

14. The assembly jig assembly according to claim 13, characterized in that: A first directional portion (1403) is provided on the rear end side wall of the push cylinder (1402), and the first directional portion (1403) cooperates with the push piston (5) to prevent the push piston (5) from rotating.

15. The assembly jig assembly according to claim 13 or 14, characterized in that: A second directional portion is provided on the rear end side wall of the push rod (1401), and the second directional portion cooperates with the locking buckle (6) to prevent 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 provided at the rear end of the push rod (1401), and the depth of the blind hole (1404) is greater 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 the piston rod of the injection piston (5) do not interfere with each other.

17. The assembly jig assembly according to claim 13 or 14, characterized in that: A limit block is provided at the front end of the push rod (1401), and 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) contacts the limit block and stops moving relative to the push rod (1401).

18. The assembly jig assembly according to claim 13 or 14, characterized in that: Also includes: The second assembly jig (15); The second assembly jig (15) comprises a base (1501) and a protruding portion (1502); The protrusion (1502) is arranged at the front end of the base (1501); the length of the protrusion (1502) in the front-to-back direction is greater than a second preset value, so that the protrusion (1502) can fix the locking buckle (6) in the locking position.

19. A method for assembling an automatic injection pen, characterized in that: Using the assembly jig assembly according to any one of claims 13 to 18 to assemble the automatic injection pen according to any one of claims 1 to 12, comprising: The locking hook (8) is fixedly mounted on the rear end of the pen body and pen holder (1); Placing the second spring (10) at the rear end of the push piston (5); Placing the first spring (12) at the rear end of the locking buckle (6); Placing the locking buckle (6) at the rear end of the injection piston (5); The push rod (1401) of the first assembly fixture (14) pushes the locking buckle (6) to move toward the rear end of the pen body and pen holder (1), until the push rod (1401) pushes the locking buckle (6) to reach the unlocking position, and the first spring (12) moves toward the rear end of the pen body and pen holder (1) under the pushing force of the locking buckle (6); The push cylinder (1402) of the first assembly fixture (14) pushes the push piston (5) to move toward the rear end of the pen body and pen barrel (1) until the piston buckle (501) and the locking hook (8) cooperate, and the second spring (10) moves toward the rear end of the pen body and pen barrel (1) under the thrust of the push piston (5); The push rod (1401) is moved toward the front end, and the locking buckle (6) is moved toward 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) is tightly sleeved on the piston buckle (501) and the locking hook (8); After the locking buckle (6) is tightly sleeved onto 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 cylinder (1).

20. The automatic injection pen assembly method according to claim 19, characterized in that: A second directional portion is provided on the rear end side wall of the push rod (1401), and the second directional portion cooperates with the locking buckle (6) to prevent the locking buckle (6) from rotating. Before the push rod (1401) of the first assembly jig (14) pushes the locking buckle (6) to move toward the rear end of the pen body and pen holder (1), the method further comprises: The second directional portion of the push rod (1401) is matched with the locking buckle (6).

21. The method for assembling an automatic injection pen according to claim 19 or 20, characterized in that: A first directional portion (1403) is provided on the rear end side wall of the push cylinder (1402), and the first directional portion (1403) cooperates with the push piston (5) to prevent the push piston (5) from rotating. Before the push cylinder (1402) of the first assembly jig (14) pushes the push piston (5) to move toward the rear end of the pen body and pen barrel (1), the method further comprises: The first orientation portion (1403) of the push cylinder (1402) is matched with the push piston (5).

22. The method for assembling an automatic injection pen according to claim 19 or 20, characterized in that: A limit block is provided at the front end of the push rod (1401), and the limit block is used to limit the movement of the push cylinder (1402). Before the push cylinder (1402) of the first assembly fixture (14) pushes the injection piston (5) to move toward the rear end of the pen body and pen cylinder (1), the method further comprises: The push tube (1402) is inserted into the push rod (1401) until the front end of the push tube (1402) abuts against the limit block of the push rod (1401), so that the push tube (1402) and the push rod (1401) move synchronously toward the rear end of the pen body and pen holder (1).

23. The method for assembling an automatic injection pen according to claim 19 or 20, characterized in that: The rear end of the locking buckle (6) is provided with a spring positioning portion, and the placing of the first spring (12) at the rear end of the locking buckle (6) comprises: The front end of the first spring (12) is matched with the spring positioning portion.

24. The method for assembling an automatic injection pen according to claim 23, characterized in that: The spring positioning portion is a spring groove (603), and the step of matching the front end of the first spring (12) with the spring positioning portion comprises: The front end of the first spring (12) is installed in the spring groove (603).

25. The method for assembling an automatic injection pen according to claim 19 or 20, characterized in that: After withdrawing the push rod (1401) and the push tube (1402) from the front end of the pen body and pen tube (1), the method further comprises: Inserting the second assembly jig (15) from the rear end of the pen body and pen holder (1) so that the raised portion (1502) of the second assembly jig (15) abuts against the rear end of the locking buckle (6) so that the locking buckle (6) is stationary relative to the pen body and pen holder (1); Pushing the needle guard (4) into the front end of the pen body and pen barrel (1) until the needle guard (4) and the locking buckle (6) are locked with each other; The second assembly jig (15) is pulled out from the rear end of the pen body and pen holder (1).

26. The method for assembling an automatic injection pen according to claim 24, characterized in that: Before pushing the needle guard (4) into the pen body and pen holder (1) from the front end, the method further comprises: Installing the syringe (1301) in the refill holder (3); Matching the needle guard (4) with the pen core holder (3); Before pulling out the second assembly jig (15) from the rear end of the pen body and pen holder (1), the method further comprises: The pen core frame (3) is pushed into the front end of the pen body and pen holder (1) until the pen core frame (3) and the pen body and pen holder (1) are locked together.

27. The method for assembling an automatic injection pen according to claim 25, characterized in that: The automatic injection pen comprises an explosion-proof sleeve (9), and before the syringe (1301) is installed in the cartridge holder (3), the method further comprises: The explosion-proof sleeve (9) is arranged at the rear end of the syringe (1301).

Images