Assembly connection structure for a combination injection device

Abstract

The utility model discloses a kind of subassembly connecting structure of combined injection device, including first subassembly and second subassembly;The first subassembly is used to install for medicine bottle;The first subassembly is provided with first guide structure, first buckle cooperation structure and second buckle cooperation structure;The second subassembly is used to play the role of push injection;The second subassembly is provided with second guide structure, third buckle cooperation structure and fourth buckle cooperation structure;The second guide structure is used to be movably cooperated with first guide structure, and third buckle cooperation structure is used to be buckled with first buckle cooperation structure;Fourth buckle cooperation structure is used to be buckled with second buckle cooperation structure.The utility model makes the connection of first subassembly and second subassembly be relatively simple, fast, can save connection time, improve connection efficiency, and after assembly, it is not disassembled, avoid repeated use.

Description

Technical Field

[0001] This utility model relates to the field of injection devices, and more specifically to a component connection structure for a combined injection device. Background Technology

[0002] Injection devices are commonly used in the medical industry, primarily for the rapid administration of medications to patients. With continuous technological advancements, some injection devices are now designed as modular units, comprising a first sub-component and a second sub-component. During the manufacturing process, medical device manufacturers produce both the first and second sub-components before supplying them to pharmaceutical companies.

[0003] Pharmaceutical companies assemble an injection device from a first sub-component, a second sub-component, and a vial (pharmacy packaging material). Specifically, the vial is first installed on the first sub-component, and then the second sub-component is connected to the first sub-component to complete the process. However, the current connection between the first and second sub-components is relatively cumbersome and requires a long assembly time, thus affecting its connection efficiency. Utility Model Content

[0004] In order to overcome the shortcomings of the prior art, the purpose of this utility model is to provide a component connection structure for a combined injection device, which makes the connection between the first sub-component and the second sub-component simpler and faster, and can improve the connection efficiency.

[0005] The objective of this utility model is achieved through the following technical solution:

[0006] A component connection structure for a combined injection device includes a first sub-component and a second sub-component;

[0007] The first sub-component is used for installing medicine bottles; the first sub-component is provided with a first guide structure, a first snap-fit ​​structure and a second snap-fit ​​structure;

[0008] The second sub-component is used to push the injection; the second sub-component is provided with a second guide structure, a third snap-fit ​​structure and a fourth snap-fit ​​structure; the second guide structure is used to move and cooperate with the first guide structure, the third snap-fit ​​structure is used to engage with the first snap-fit ​​structure, and the fourth snap-fit ​​structure is used to engage with the second snap-fit ​​structure.

[0009] The first sub-component includes a first housing, and the second sub-component includes a second housing; the first housing and the second housing are at least partially sleeved together, the first snap-fit ​​structure and the first guide structure are both disposed on the first housing, and the third snap-fit ​​structure and the second guide structure are both disposed on the second housing.

[0010] The second sub-assembly includes a control lever, an action push rod, and a drive spring. The control lever is provided with a first control arm, and the first control arm is provided with a first elastic locking head. The action push rod is provided with a push rod latch, and the first elastic locking head is used to engage with the push rod latch. The drive spring is disposed between the control lever and the action push rod.

[0011] The second housing is equipped with a knob component, which has a knob slot. The second housing is fitted over the end of the knob component and has a support protrusion that engages with the knob slot. The second sub-assembly further includes a push cylinder component, which is installed inside the second housing. The knob component has a knob fastening structure, and the push cylinder component has a push cylinder fastening structure for engaging with the knob fastening structure. The control lever is at least partially installed inside the push cylinder component. The push cylinder component and the control lever are connected... The system is equipped with a first linear guide structure for guiding relative movement between the push cylinder component and the control rod. The control rod is equipped with a second control arm with a second elastic locking head. The push cylinder component has a push cylinder groove, the groove wall of which includes an inclined mating surface. The second elastic locking head is used to abut against the inclined mating surface. The push cylinder component is equipped with a push cylinder locking arm, and the second housing has an internal mating part with an inclined abutting surface. The push cylinder locking arm is used to abut against the inclined abutting surface.

[0012] The second sub-assembly further includes a built-in sleeve and a trigger spring; the trigger spring abuts against the push cylinder component and the built-in sleeve; the built-in sleeve is movably fitted onto the push cylinder component, the built-in sleeve is provided with a sleeve retaining arm, the push cylinder component is provided with a push cylinder groove, and the sleeve retaining arm is used to abut against the groove wall of the push cylinder groove; a second linear guide structure is provided between the built-in sleeve and the second housing, the second linear guide structure is used to guide relative movement between the built-in sleeve and the second housing; a positioning flange is provided on the second housing, and a sleeve buckle is provided on the built-in sleeve, the sleeve buckle engaging with the positioning flange.

[0013] The push cylinder component includes a push cylinder body and a push cap; the push cap is sleeved with the push cylinder body, the push cap is provided with a push cap groove, the push cylinder body is provided with a push cylinder buckle, and the push cylinder buckle is fastened to the push cap groove.

[0014] A receiving area for accommodating damping oil is formed between the push cylinder component and the control rod.

[0015] The first sub-assembly further includes a syringe holder and a needle retraction spring. The second snap-fit ​​structure is disposed on the syringe holder, and the fourth snap-fit ​​structure is disposed on the push-tube component. The syringe holder is installed inside the first housing, and the needle retraction spring is disposed between the first housing and the syringe holder. A cylinder is installed inside the first housing, and the syringe holder and the cylinder are connected by snap-fit.

[0016] One of the third buckle-fitting structure and the first buckle-fitting structure is provided with a first inclined buckle, and the other is provided with a first slot; one of the fourth buckle-fitting structure and the second buckle-fitting structure is provided with a second inclined buckle, and the other is provided with a second slot.

[0017] One of the second guide structure and the first guide structure is a first guide groove, and the other is a first guide protrusion for being movably embedded in the first guide groove.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] This utility model provides a component connection structure for a combined injection device. By providing a first guide structure, a first snap-fit ​​structure, and a second snap-fit ​​structure in the first sub-component, and a second guide structure, a third snap-fit ​​structure, and a fourth snap-fit ​​structure in the second sub-component, the first and second sub-components can be positioned using the second guide structure in conjunction with the first guide structure. The connection between the first and second sub-components can be quickly completed by engaging the third snap-fit ​​structure with the first snap-fit ​​structure and the fourth snap-fit ​​structure with the second snap-fit ​​structure. This makes the connection simple and quick, saving connection time and improving connection efficiency. Furthermore, by rationally designing the second sub-component, its overall structure remains relatively stable in static and transport states, reducing or even preventing abnormal situations. In addition, the first and second sub-components are not disassembled after assembly, avoiding reuse. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure after the first and second sub-components of this utility model are connected;

[0021] Figure 2 This is a schematic diagram of the structure of the second sub-component;

[0022] Figure 3 This is an exploded view of the second sub-component;

[0023] Figure 4 This is a structural diagram of the first sub-component;

[0024] Figure 5This is an exploded view of the first sub-component;

[0025] Figure 6 This is a schematic diagram of the pusher body.

[0026] Figure 7 A schematic diagram of the pusher body from another direction;

[0027] Figure 8 This is a schematic diagram of the control lever structure;

[0028] Figure 9 This is a schematic diagram of the second shell structure;

[0029] Figure 10 This is a schematic diagram of the interior of the second housing;

[0030] Figure 11 This is a schematic diagram of the syringe holder structure;

[0031] Figure 12 A schematic diagram of the main shell structure;

[0032] Figure 13 This is a schematic diagram of the internal sleeve structure;

[0033] Figure 14 This is a structural diagram of the knob component. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0035] like Figure 1-14 As shown, a component connection structure of a combined injection device includes a first sub-component 20 and a second sub-component 10.

[0036] The first sub-component 20 is used for installing the medicine bottle 30; the first sub-component 20 is provided with a first guide structure 211, a first snap-fit ​​structure 212 and a second snap-fit ​​structure 241;

[0037] The second sub-component 10 is used to push the injection; the second sub-component 10 is provided with a second guide structure 118, a third snap-fit ​​structure 112 and a fourth snap-fit ​​structure 144; the second guide structure 118 is used to movably cooperate with the first guide structure 211, the third snap-fit ​​structure 112 is used to fasten with the first snap-fit ​​structure 212; the fourth snap-fit ​​structure 144 is used to fasten with the second snap-fit ​​structure 241.

[0038] During assembly, once the medicine bottle 30 is installed inside the first sub-component 20, the positioning of the first sub-component 20 and the second sub-component 10 can be achieved by the cooperation of the second guide structure 118 and the first guide structure 211. Furthermore, the connection between the first sub-component 20 and the second sub-component 10 can be quickly completed by the engagement of the third snap-fit ​​structure 112 with the first snap-fit ​​structure 212 and the fourth snap-fit ​​structure 144 with the second snap-fit ​​structure 241. Therefore, the component connection structure of the combined injection device provided by this utility model, by providing the first guide structure 211, the first snap-fit ​​structure 212, and the second snap-fit ​​structure 241 in the first sub-component 20, provides a modular connection structure for the first sub-component 20. 241. By providing a second guide structure 118, a third snap-fit ​​structure 112, and a fourth snap-fit ​​structure 144 in the second sub-component 10, the positioning of the first sub-component 20 and the second sub-component 10 can be achieved by first using the second guide structure 118 in conjunction with the first guide structure 211. Then, by engaging the third snap-fit ​​structure 112 with the first snap-fit ​​structure 212 and engaging the fourth snap-fit ​​structure 144 with the second snap-fit ​​structure 241, the connection of the first sub-component 20 and the second sub-component 10 can be quickly completed, making the connection of the first sub-component 20 and the second sub-component 10 simpler and faster, saving connection time and improving connection efficiency.

[0039] One of the second guide structure 118 and the first guide structure 211 is a first guide groove, and the other is a first guide protrusion for being movably embedded in the first guide groove. That is, if the second guide structure 118 is set as the first guide groove, then the first guide structure 211 is set as the first guide protrusion; if the second guide structure 118 is set as the first guide protrusion, then the first guide structure 211 is set as the first guide groove. The first sub-component 20 and the second sub-component 10 can be aligned through the cooperation of the first guide groove and the first guide protrusion. During the assembly process, the first sub-component 20 and the second sub-component 10 can be assembled into place through the relative movement between the first guide groove and the first guide protrusion, so that the third snap-fit ​​structure 112 can be engaged with the first snap-fit ​​structure 212 and the fourth snap-fit ​​structure 144 can be engaged with the second snap-fit ​​structure 241.

[0040] One of the third snap-fit ​​structure 112 and the first snap-fit ​​structure 212 is provided with a first inclined buckle, and the other is provided with a first slot. In this embodiment, the first snap-fit ​​structure 212 is a first inclined buckle, and the third snap-fit ​​structure 112 is a first slot.

[0041] Of course, in addition to this, the third snap-fit ​​structure 112 and the first snap-fit ​​structure 212 can also be combined with a clip and a U-shaped clip bracket, as long as they can be snapped together. However, the most preferred embodiment of this utility model is to provide a first inclined buckle on one of the third snap-fit ​​structure 112 and the first snap-fit ​​structure 212 and a first slot on the other. This facilitates connection and assembly, and disassembly after connection will damage the first inclined buckle, thus playing a role in preventing disassembly after connection.

[0042] One of the fourth snap-fit ​​structure 144 and the second snap-fit ​​structure 241 is provided with a second inclined buckle, and the other is provided with a second slot. In this embodiment, the second snap-fit ​​structure 241 is a second slot, and the fourth snap-fit ​​structure 144 is a second inclined buckle.

[0043] Of course, in addition to this, the fourth snap-fit ​​structure 144 and the second snap-fit ​​structure 241 can also be combined with a clip and a U-shaped clip bracket, etc. However, the most preferred embodiment of this utility model is to provide a second inclined buckle on one of the four snap-fit ​​structures 144 and the second snap-fit ​​structure 241 and a second slot on the other, which can facilitate connection and assembly while preventing disassembly after connection.

[0044] Specifically, the first sub-component 20 includes a first housing, and the second sub-component 10 includes a second housing 11. The first housing and the second housing 11 are at least partially fitted together. The first snap-fit ​​structure 212 and the first guide structure 211 are both disposed on the first housing, and the third snap-fit ​​structure 112 and the second guide structure 118 are both disposed on the second housing 11 to facilitate manufacturing. The at least partial fitting of the first housing and the second housing 11 can mean that the first housing can be partially fitted over the second housing 11, or that the second housing 11 can be partially fitted over the first housing.

[0045] The second sub-component 10 includes a control lever 15, an actuating push rod 16, and a drive spring 42. The control lever 15 is provided with a first control arm 153, which has a first elastic locking head. The actuating push rod 16 is provided with a push rod locking position 161, and the first elastic locking head is used to engage with the push rod locking position 161. The drive spring 42 is disposed between the control lever 15 and the actuating push rod 16. During injection, the elastic force applied by the drive spring 42 can cause the actuating push rod 16 to move, thereby enabling the actuating push rod 16 to perform an injection pushing action. By using the first elastic locking head to engage with the push rod locking position 161, the actuating push rod 16 can be locked to prevent the drive spring 42 from pushing the actuating push rod 16 downward, ensuring structural stability during transportation and avoiding abnormal situations triggered during transportation.

[0046] A knob 12 is mounted on the second housing 11. The knob 12 has a knob slot 122. The second housing 11 is fitted over the end of the knob 12, and a support protrusion 113 is provided on the second housing 11. The support protrusion 113 is engaged in the knob slot 122. The second sub-assembly 10 also includes a push cylinder component, which is installed inside the second housing 11. The knob 12 has a knob fastening structure 310, and the push cylinder component has a push cylinder fastening structure 320, which is used to engage with the knob fastening structure 310. The control rod 15 is at least partially installed inside the push cylinder component; a first linear guide structure is provided between the push cylinder component and the control rod 15, the first linear guide structure is used to guide relative movement between the push cylinder component and the control rod 15; the control rod 15 is provided with a second control arm 154, the second control arm 154 is provided with a second elastic clamping head, the push cylinder component is provided with a push cylinder groove, the groove wall of the push cylinder groove includes an inclined mating surface 146, the second elastic clamping head is used to abut against the inclined mating surface 146, which can improve the stability of the assembly of the push cylinder component and the control rod 15.

[0047] Specifically, the knob 12 is provided with a knob slot 122, the second housing 11 is fitted onto the end of the knob 12, and the second housing 11 is provided with a support protrusion 113, which is fitted into the knob slot 122.

[0048] Specifically, the first linear guide structure includes a third guide structure disposed on the control rod 15 and a fourth guide structure disposed on the push cylinder member and used to engage with the third guide structure. Thus, by engaging the third guide structure and the fourth guide structure, the relative movement of the two can be used to guide the relative movement between the push cylinder member and the control rod 15.

[0049] Of course, in addition to the above structures, the first linear guide structure is not limited to the above structures. Other structures can also be used, as long as they can be used to guide relative movement between the push cylinder component and the control rod 15.

[0050] One of the third and fourth guide structures is a control guide groove, and the other is a control guide protrusion that is movably embedded in the control guide groove. That is, if the fourth guide structure is set as a control guide groove, then the third guide structure is set as a control guide protrusion; if the fourth guide structure is set as a control guide protrusion, then the third guide structure is set as a control guide groove. The relative movement between the guide push cylinder component and the control rod 15 can be achieved through the cooperation of the control guide groove and the control guide protrusion.

[0051] The pusher component is provided with a pusher arm 147, and the second housing 11 is provided with a built-in mating part. The built-in mating part is provided with an inclined abutment surface 115. The pusher arm 147 is used to abut against the inclined abutment surface 115. Thus, through the cooperation between the pusher arm 147 and the inclined abutment surface 115, the pusher component and the second housing 11 are stably assembled under conditions such as transportation.

[0052] The second sub-assembly 10 further includes a built-in sleeve 13 and a trigger spring 41; the trigger spring 41 abuts against the push cylinder component and the built-in sleeve 13; the built-in sleeve 13 is movably fitted onto the push cylinder component, the built-in sleeve 13 is provided with a sleeve retaining arm 330, the push cylinder component is provided with a push cylinder groove 340, the sleeve retaining arm 330 is used to abut against the groove wall of the push cylinder groove 340 to prevent the built-in sleeve 13 from being pushed out by the trigger spring 41; a second linear guide structure is provided between the built-in sleeve 13 and the second housing 11, the second linear guide structure is used to guide relative movement between the built-in sleeve 13 and the second housing 11; the second housing 11 is provided with a positioning flange 117, the built-in sleeve 13 is provided with a sleeve buckle 134, the sleeve buckle 134 is fastened to the positioning flange 117. By adopting the above combination, the stability of the assembly of the inner sleeve 13 with the push cylinder component and the assembly of the inner sleeve 13 with the second housing 11 can be improved, so as to ensure structural stability during transportation and other conditions.

[0053] The built-in sleeve 13 may be provided with a sleeve protrusion 133, and the push cylinder component may be provided with a push cylinder guide groove 145. The sleeve protrusion 133 is embedded in the push cylinder guide groove 145 so that the built-in sleeve 13 can be movably fitted onto the push cylinder component.

[0054] Of course, in addition to this, the built-in sleeve 13 can be movably fitted onto the push cylinder component through other structures. For example, the built-in sleeve 13 can be provided with a sleeve guide groove, and the push cylinder component can be provided with a guide protrusion, which is embedded in the sleeve guide groove.

[0055] The second linear guide structure includes a fifth guide structure 116 disposed on the second housing 11 and a sixth guide structure 132 disposed on the inner sleeve 13 and used to engage with the fifth guide structure 116. Thus, by engaging the fifth guide structure 116 and the sixth guide structure 132, the relative movement between the two can be used to guide the relative movement between the inner sleeve 13 and the second housing 11.

[0056] One of the fifth guide structure 116 and the sixth guide structure 132 is a third guide groove, and the other is a third guide protrusion that is movably embedded in the third guide groove. That is, if the sixth guide structure 132 is set as a third guide groove, then the fifth guide structure 116 is set as a third guide protrusion; if the sixth guide structure 132 is set as a third guide protrusion, then the fifth guide structure 116 is set as a third guide groove. The relative movement between the guide inner sleeve 13 and the second housing 11 can be realized through the cooperation of the third guide groove and the third guide protrusion.

[0057] Of course, the second linear guide structure is not limited to the above structure, and other structures can also be used, as long as they can be used to guide the relative movement between the inner sleeve 13 and the second housing 11.

[0058] A receiving area 1410 for accommodating damping oil is formed between the push cylinder component and the control rod 15.

[0059] The push cylinder component includes a push cylinder body 14 and a push cap 17; the push cap 17 is sleeved with the push cylinder body 14, the push cap 17 is provided with a push cap slot, and the push cylinder body 14 is provided with a push cylinder buckle, the push cylinder buckle is used to fasten to the push cap slot, so as to realize the connection between the push cylinder body 14 and the push cap 17.

[0060] The push cylinder body 14 may be provided with a push cylinder guide groove, and the push cap 17 is provided with a push cap guide protrusion inserted into the push cylinder guide groove to restrict the relative rotation of the push cylinder body 14 and the push cap 17.

[0061] The control lever 15 is fitted with a first sealing ring 44, and the push cylinder component is fitted with a second sealing ring 46.

[0062] The first sub-assembly 20 further includes a syringe holder 24 and a needle retraction spring 43. A second snap-fit ​​structure 241 is disposed on the syringe holder 24, and a fourth snap-fit ​​structure 144 is disposed on the push-tube component. The syringe holder 24 is installed inside the first housing, and the needle retraction spring 43 is disposed between the first housing and the syringe holder 24. A cylinder 23 is installed inside the first housing, and the syringe holder 24 and the cylinder 23 are connected by snap-fit. The cylinder 23 is used to abut against the inner sleeve 13. The syringe holder 24 is used for mounting the medicine bottle 30.

[0063] The first housing includes a main housing 21 and a pen cap 22, the pen cap 22 being mounted on the lower housing 21 and connected by a detachable snap-fit. Of course, the structure of the first housing can also be configured according to actual needs.

[0064] A gasket 25 is fixed to the syringe holder 24. The gasket 25 can be fixed to the syringe holder 24 by means of snap-fit, adhesive bonding or other methods.

[0065] The assembly process of the first sub-component 20 is as follows: a) Fix the gasket 25 to the syringe holder 24 and put the needle retraction spring 43 on the syringe holder 24; b) Insert the syringe body 23 into the main shell 21 from the bottom, and then install the syringe holder 24, needle retraction spring 43 and gasket 25 as a whole and insert them into the main shell 21 and syringe body 23 from the top, and connect the syringe holder 24 and syringe body 23 with snap fasteners; c) Insert the pen cap 22 into the main shell 21 and connect it with a detachable snap fastener, thereby quickly completing the installation of the first sub-component 20.

[0066] The above embodiments are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. A component connection structure for a combined injection device, characterized in that, Includes the first sub-component and the second sub-component; The first sub-component is used for installing medicine bottles; the first sub-component is provided with a first guide structure, a first snap-fit ​​structure and a second snap-fit ​​structure; The second sub-component is used to push the injection; the second sub-component is provided with a second guide structure, a third snap-fit ​​structure and a fourth snap-fit ​​structure; the second guide structure is used to move and cooperate with the first guide structure, the third snap-fit ​​structure is used to engage with the first snap-fit ​​structure, and the fourth snap-fit ​​structure is used to engage with the second snap-fit ​​structure.

2. The component connection structure of the combined injection device as described in claim 1, characterized in that: The first sub-component includes a first housing, and the second sub-component includes a second housing; the first housing and the second housing are at least partially sleeved together, the first snap-fit ​​structure and the first guide structure are both disposed on the first housing, and the third snap-fit ​​structure and the second guide structure are both disposed on the second housing.

3. The component connection structure of the combined injection device as described in claim 2, characterized in that: The second sub-assembly includes a control lever, an action push rod, and a drive spring. The control lever is provided with a first control arm, and the first control arm is provided with a first elastic locking head. The action push rod is provided with a push rod latch, and the first elastic locking head is used to engage with the push rod latch. The drive spring is disposed between the control lever and the action push rod.

4. The component connection structure of the combined injection device as described in claim 3, characterized in that: The second housing is equipped with a knob component, which has a knob slot. The second housing is fitted over the end of the knob component and has a support protrusion that engages with the knob slot. The second sub-assembly further includes a push cylinder component, which is installed inside the second housing. The knob component has a knob fastening structure, and the push cylinder component has a push cylinder fastening structure for engaging with the knob fastening structure. The control rod is at least partially installed inside the push cylinder component. A first linear guide structure is provided between the push cylinder component and the control rod to guide relative movement between them. The control rod has a second control arm with a second elastic locking head. The push cylinder component has a push cylinder groove, the groove wall of which includes an inclined mating surface. The second elastic locking head abuts against the inclined mating surface. The pusher component is provided with a pusher arm, and the second housing is provided with a built-in mating part. The built-in mating part is provided with an inclined abutting surface, and the pusher arm is used to abut against the inclined abutting surface.

5. The component connection structure of the combined injection device as described in claim 4, characterized in that: The second sub-assembly further includes a built-in sleeve and a trigger spring; the trigger spring abuts against the push cylinder component and the built-in sleeve; the built-in sleeve is movably fitted onto the push cylinder component, the built-in sleeve is provided with a sleeve retaining arm, the push cylinder component is provided with a push cylinder groove, and the sleeve retaining arm is used to abut against the groove wall of the push cylinder groove; a second linear guide structure is provided between the built-in sleeve and the second housing, the second linear guide structure is used to guide relative movement between the built-in sleeve and the second housing; a positioning flange is provided on the second housing, and a sleeve buckle is provided on the built-in sleeve, the sleeve buckle engaging with the positioning flange.

6. The component connection structure of the combined injection device as described in claim 4, characterized in that: The push cylinder component includes a push cylinder body and a push cap; the push cap is sleeved with the push cylinder body, the push cap is provided with a push cap groove, the push cylinder body is provided with a push cylinder buckle, and the push cylinder buckle is fastened to the push cap groove.

7. The component connection structure of the combined injection device as described in claim 4, characterized in that: A receiving area for accommodating damping oil is formed between the push cylinder component and the control rod.

8. The component connection structure of the combined injection device as described in any one of claims 5-7, characterized in that: The first sub-assembly further includes a syringe holder and a needle retraction spring. The second snap-fit ​​structure is disposed on the syringe holder, and the fourth snap-fit ​​structure is disposed on the push-tube component. The syringe holder is installed inside the first housing, and the needle retraction spring is disposed between the first housing and the syringe holder. A cylinder is installed inside the first housing, and the syringe holder and the cylinder are connected by snap-fit.

9. The component connection structure of the combined injection device as described in claim 1, characterized in that: One of the third buckle-fitting structure and the first buckle-fitting structure is provided with a first inclined buckle, and the other is provided with a first slot; one of the fourth buckle-fitting structure and the second buckle-fitting structure is provided with a second inclined buckle, and the other is provided with a second slot.

10. The component connection structure of the combined injection device as described in claim 1, characterized in that: One of the second guide structure and the first guide structure is a first guide groove, and the other is a first guide protrusion for being movably embedded in the first guide groove.

Images