CN116509593A - Injection device - Google Patents

Abstract

The invention discloses an injection device. The injection device comprises a column-shaped injection substrate, an injection channel hole penetrating through the injection substrate is formed in the injection substrate along an axis, a nozzle is arranged at one end of the injection substrate, an injection outlet and an injection channel which is communicated with the injection outlet and the injection channel hole are arranged on the nozzle, a check valve is arranged in the injection channel and used for controlling the injection channel to conduct unidirectionally along the injection direction, a plunger is arranged in the injection channel hole, the plunger is slidably inserted from one end, far away from the nozzle, of the injection channel hole, a liquid inlet channel is arranged on the side wall of the injection substrate, penetrates through the side wall of the injection substrate and is used for conveying liquid medicine to be applied to the injection channel hole. The liquid inlet channel can automatically fill liquid medicine in the process of withdrawing the plunger, and the injection device is simple and convenient to operate, simple in structure and high in injection efficiency.

Description

Injection device

Technical Field

The invention relates to the technical field of medical appliances, in particular to an injection device.

Background

At present, various animal viruses in the world are abused, and various poultry and pet farms and companies suffer from great losses caused by epidemic diseases. In the face of epidemic diseases, the vaccine is the most effective control means for various poultry and pets. However, the use of veterinary syringes is now widely practiced, and the re-aspiration of the liquid medicine is required for each injection, which is extremely inefficient and difficult to meet the large-scale injection of animal vaccines.

Disclosure of Invention

The invention aims to solve the technical problem of providing an injection device which is simple and convenient to operate, simple in structure, capable of self-filling liquid medicine, free from repeated sucking of the liquid medicine and high in injection efficiency.

In order to solve the technical problems, the invention provides an injection device, which comprises a column-shaped injection substrate, wherein an injection passage hole penetrating through the injection substrate is formed in the injection substrate along an axis, a nozzle is arranged at one end of the injection substrate, an injection outlet and an injection passage communicated with the injection outlet and the injection passage hole are arranged on the nozzle, a check valve is arranged in the injection passage and used for controlling the injection passage to conduct unidirectionally along the injection direction, a plunger is arranged in the injection passage hole, the plunger is slidably inserted from one end of the injection passage hole far away from the nozzle, a liquid inlet passage is arranged on the side wall of the injection substrate, and the liquid inlet passage penetrates through the side wall of the injection substrate and is used for conveying liquid medicine to be applied to the injection passage hole.

In summary, by adopting the injection device, the liquid inlet channel can automatically fill the liquid medicine in the process of withdrawing the plunger, and the injection device is simple and convenient to operate, simple in structure, high in injection efficiency and capable of injecting without needle.

Drawings

In the drawings:

fig. 1 is an overall construction view of an injection device according to the present invention.

Fig. 2 is a schematic perspective cutaway view of an injection device of the present invention.

FIG. 3 is a cut-away view of the injection matrix of the injection device of the present invention.

Fig. 4 is a view showing the structure of an injection matrix of the injection device of the present invention.

Fig. 5 is a view showing a constitution of a guide sleeve of the injection device of the present invention.

Fig. 6 is a cut-away view of the dispensing end of the injection device of the present invention.

Fig. 7 is a view showing a structure of a dispensing end body of the injection device of the present invention.

Fig. 8 is a sectional view of the injection end body of the injection device of the present invention.

Fig. 9 is a view showing a structure of a jet end body of the injection device of the present invention.

Fig. 10 is a cut-away view of the rear seat of the injection device of the present invention.

Fig. 11 is a rear seat structure view of the injection device of the present invention.

FIG. 12 is a cut-away view of a medical fluid connector of the injection apparatus of the present invention.

FIG. 13 is a schematic view showing a construction of a medical fluid connector of an injection apparatus according to the present invention.

Fig. 14 is a front cover cut-away view of the injection device of the present invention.

Fig. 15 is a partial plan cut-away view of the injection device of the present invention.

In the figure, 1, injecting a matrix; 11. a pin; 12. a first jack; 13. a pin; 14. a stepped shaft section; 15. a baffle ring; 2. an injection passage hole; 21. a guide hole; 22. a guide sleeve; 3. a nozzle; 301. a dispensing end body; 3011. a second groove; 3012. a pin hole; 3013. a second jack; 302. a spray end body; 3021. a cover plate; 3022. a cover side wall; 3023. a first protrusion; 3024. a second protrusion; 303. a seal ring; 31. an ejection port; 32. an ejection channel; 321. a first through hole; 322. a first groove; 323. a second through hole; 4. a check valve; 41. a first spring; 42. a valve core; 5. a plunger; 6. a liquid inlet channel; 61. a liquid inlet; 62. a liquid outlet; 63. a buffer chamber; 7. a rear seat; 71. a base; 72. a bump structure; 73. a liquid feed passage hole; 731. a first section of liquid feeding hole; 732. a second section of liquid feeding hole; 733. a third section of liquid feeding hole; 734. a fourth section of liquid feeding hole; 74. a medical fluid connector; 741. an end portion; 7411. a first connection thread; 742. a connecting pipe; 7421. a second connecting thread; 743. a first frustum body; 744. a second cone table; 745. a connection hole; 75. an annular flange; 8. a liquid medicine container; 9. a front cover; 91. a slot hole; 92. and a second spring.

Detailed Description

The following describes the embodiments of the present invention further with reference to the drawings. The description of these embodiments is provided to assist understanding of the present invention, but is not intended to limit the present invention.

It should be noted that the words "inner" and "outer" are used in the following description to refer to directions toward or away from, respectively, the geometric center of a particular component.

Example 1

Figures 1-15 illustrate an injection device of the present invention. As shown in fig. 1 and 2, the injection device comprises a column-shaped injection base body 1, an injection channel hole 2 penetrating through the injection base body 1 is formed in the injection base body 1 along an axis, a nozzle 3 is arranged at one end of the injection base body 1, an injection outlet 31 and an injection channel 32 communicating the injection outlet 31 with the injection channel hole 2 are arranged on the nozzle 3, a check valve 4 is arranged in the injection channel 32, the check valve 4 is used for controlling the injection channel 32 to conduct unidirectionally along the injection direction, a plunger 5 is arranged in the injection channel hole 2, the plunger 5 is slidably inserted from one end of the injection channel hole 2 far away from the nozzle 3, a liquid inlet channel 6 is arranged on the side wall of the injection base body 1, and the liquid inlet channel 6 penetrates through the side wall of the injection base body 1 and is used for conveying liquid medicine to be applied to the injection channel hole 2.

As shown in fig. 3 and 4, the injection base 1 has a main body structure of a column shape, and a through hole, i.e., an injection passage hole 2 is opened at a central axis, and for convenience of description, one end of the injection passage hole 2, which is far from the nozzle 3, is referred to as a tail end, and the other end is referred to as a front end. The liquid inlet channel 6 penetrates the injection matrix 1, a liquid inlet 61 is formed on the outer side surface, a liquid outlet 62 is formed on the inner side surface, and the liquid outlet 62 is arranged at the middle position of the injection matrix 1.

In addition, the liquid inlet channel 6 can be directly arranged into a straight hole or inclined hole structure, and the processing is easy. The structure of a buffer cavity 63 as shown in fig. 4 can also be designed, the buffer cavity 63 is in a ring-shaped sheet cavity structure and is arranged in the injection matrix 1, and the inner side surface and the outer side surface of the buffer cavity 63 are respectively provided with a liquid outlet 62 and a liquid inlet 61. Since the plunger 5 is pulled back in the injection passage hole 2 to generate negative pressure, the flow rate of the liquid medicine flowing into the injection passage hole 2 is large, and bubbles are liable to be generated, if the bubbles are in the injection passage hole 2, adverse effects on injection are generated, the buffer chamber 63 is provided to reduce the flow rate of the liquid medicine, and the generated bubbles can be stopped in the buffer chamber 63 and further returned to the liquid medicine container 8, so that adverse effects of the bubbles are avoided.

In order to facilitate the insertion of the plunger 5 from the tail end of the injection passage hole 2, a guide hole 21 is arranged at the tail end of the injection passage hole 2, the guide hole 21 is coaxial with the injection passage hole 2, and the aperture is larger than that of the injection passage hole 2, the injection device further comprises a guide sleeve 22, the guide sleeve 22 can be slidably embedded into the guide hole 21, and the plunger 5 can be slidably embedded into the inner hole of the guide sleeve 22, so that the guide sleeve 22 can be sleeved at the insertion end of the plunger 5 when the plunger 5 is replaced and installed, and then the plunger 5 can be conveniently and rapidly inserted into the injection passage hole 2 when the guide sleeve 22 is inserted into the guide hole 21. Alternatively, the guide sleeve 22 is constructed as shown in FIG. 5.

As shown in fig. 2 and 6-9, the nozzle 3 includes a dispensing end body 301 and a spraying end body 302, and the nozzle 3 is provided as a separate structure in order to provide a check valve 4 structure within the nozzle 3.

Optionally, the dispensing end 301 has a cylindrical disk shape, and an end surface is disposed with the end surface of the injection base 1 facing the Ji Tiege, and the two are fixedly connected. As shown in fig. 4, two pins 11 are provided vertically on the front end face of the injection base 1, and first insertion holes 12 are provided at the ends of the pins 11. As shown in fig. 6 and 7, a pin hole 3012 that is fitted to the pin 11 and a second insertion hole 3013 that penetrates from the side surface of the dispensing end body 301 to the pin hole 3012 are provided on one side end surface of the dispensing end body 301. After the dispensing end body 301 is attached to the end face of the injection base 1, the pin 11 is inserted into the pin hole 3012, and a pin 13 is inserted into the first insertion hole 12 from the second insertion hole 3013, and the pin 13 is completely embedded into the second insertion hole 3013, so that the dispensing end body 301 is fixed.

The dispensing end body 301 is provided with a first through hole 321 penetrating in the axial direction, and the first through hole 321 communicates with the injection passage hole 2 to introduce the chemical liquid into the nozzle 3. In order to enable a larger flow rate of the medical fluid to be generated, needle-free injection is realized, and the aperture of the first through hole 321 is smaller than that of the injection passage hole 2. Since the aperture of the first through hole 321 is generally much smaller than the diameter of the injection channel hole 2, a bell mouth structure is arranged at one end of the first through hole 321 close to the injection channel hole 2, so that the aperture gradually changes and the transition is slow. The whole device can realize needleless injection, the aperture of the injection passage hole 2 is 6.5-7.5 mm, preferably 7mm, and the aperture of the first through hole 321 is 0.15-0.20 mm, preferably 0.18mm; the second through hole 323 has a hole diameter of 2.3 to 2.7mm, preferably 2.5mm.

Optionally, as shown in fig. 8 and fig. 9, the injection end body 302 is in a cylindrical cap shape, and the cover is arranged at the outer sides of the ends of the dispensing end body 301 and the injection base body 1, the injection end body 302 includes a cover plate 3021 and a cover side wall 3022, a first groove 322 is arranged at the center of the inner side surface of the cover plate 3021, a second through hole 323 penetrating through the cover plate 3021 along the axis is arranged on the cover plate 3021, the port of the second through hole 323 is an injection port 31, the second through hole 323, the inner cavity of the first groove 322 and the first through hole 321 are aligned, the injection port 32 is formed by mutual communication, and the connection position between the first groove 322 and the first through hole 321 is controlled to be opened and closed by a check valve 4.

Optionally, as shown in fig. 2 and 15, the check valve 4 includes a first spring 41 and a valve core 42 disposed in a first groove 322, where the first groove 322 is in a cylindrical groove shape, the cylindrical valve core 42 can slide in the first groove 322, the first spring 41 pushes the valve core 42 to block the first through hole 321 when not injecting, forming a check valve structure, when controlling injection, the liquid medicine in the injection channel hole 2 can be ejected from the ejection port 31, and after ejection, the first through hole 321 is blocked under the action of the first spring 41, so that liquid returns.

Optionally, as shown in fig. 2, 6 and 8, the center of the end surface of the dispensing end body 301 away from the injection substrate 1 is provided with a second groove 3011, the inner side surface of the cover plate 3021 is provided with a first protrusion 3023 which is embedded in the second groove 3011, a sealing ring 303 is arranged between the end surface of the first protrusion 3023 and the bottom surface of the second groove 3011, and the sealing ring 303 is used for sealing the communication between the inner cavity of the first groove 322 and the first through hole 321.

Through setting up first recess 322 on first protruding 3023, first protruding 3023 and the gomphosis cooperation of second recess 3011 are convenient for the equipment of nozzle 3 two-part structure to and the placing of sealing washer 303, prevent effectively that the weeping.

Optionally, as shown in fig. 9, a second protrusion 3024 with a frustum shape is provided at the center of the outer side surface of the cover plate 3021, so that the injection port 31 protrudes out of the end surface of the cover plate 3021, and is convenient for adhering to the epidermis of the injection area during injection.

As shown in fig. 2, 10 and 11, the injection device further comprises a rear seat 7, the rear seat 7 comprises a sleeve-shaped seat body 71, the seat body 71 is sleeved on the outer side face of one end, far away from the nozzle 3, of the injection substrate 1, the side wall of the seat body 71 is locally protruded outwards to form a columnar protruding structure 72, an included angle between the protruding structure 72 and the axis of the seat body 71 is an acute angle, a through liquid conveying channel hole 73 is formed in the rear seat 7 along the axis of the protruding structure 72, a liquid medicine connecting piece 74 is arranged in the liquid conveying channel hole 73, and the liquid medicine connecting piece 74 is used for communicating the liquid medicine container 8 with the liquid conveying channel hole 73.

As shown in fig. 12 and 13, the medical fluid connector 74 includes a cylindrical end portion 741, a first connecting screw thread 7411 is provided on a small end cylindrical side surface of the end portion 741, the first connecting screw thread 7411 is used for connecting with a medical fluid container 8, a connecting pipe 742 is provided on a large end surface of the end portion 741, the connecting pipe 742 and the end portion 741 are coaxially arranged, the side surface of the connecting pipe 742 protrudes outwards to form a first frustum 743 and a second frustum 744, the first frustum 743 is close to the end portion 741, the diameter of a conical bottom surface of the first frustum 743 is larger than that of the second frustum 744, a second connecting screw thread 7421 is provided on an outer side surface of an end portion of the connecting pipe 742, and a connecting hole 745 communicated with an inner hole of the connecting pipe 742 is axially provided in the end portion 741.

Optionally, the liquid medicine container 8 is a liquid medicine bag, and can automatically adapt to and regulate the change of the pressure in the bag after the medicine is administrated through self deformation. The liquid medicine bag can be directly screwed on the first connecting thread 7411 through the thread opening, and can also be connected on the first connecting thread 7411 through structures such as a pipeline, a connector and the like.

As shown in fig. 10, the liquid feed passage hole 73 has a stepped hole structure, and includes a first-stage liquid feed hole 731, a second-stage liquid feed hole 732, a third-stage liquid feed hole 733, and a fourth-stage liquid feed hole 734 which are sequentially provided from outside to inside and have gradually decreasing apertures; the first section liquid feeding hole 731 is embedded and matched with the large end cylinder of the end head 741, the second section liquid feeding hole 732 is matched with the outer circle of the conical bottom of the first frustum body 743, the aperture of the third section liquid feeding hole 733 is smaller than the diameter of the conical bottom surface of the second frustum body 744, and the fourth section liquid feeding hole 734 is provided with internal threads which are in threaded connection with the second connecting threads 7421.

After the chemical liquid connector 74 is fastened to the inside of the liquid feed passage hole 73 by the second connecting screw 7421: the conical surface of the second conical table 744 and the top end of the third section liquid feeding hole 733 realize linear sealing, and a better sealing effect can be realized by matching with the thread sealing of the second connecting thread 7421, so that the leakage of liquid medicine is avoided; the outer circle of the conical bottom of the first conical frustum body 743 is positioned in the second section liquid feeding hole 732, the size of the outer circle of the conical bottom of the first conical frustum body 743 is smaller than the aperture of the second section liquid feeding hole 732 by 0.1-0.5 mm, and the guide can be provided during insertion and installation, so that the end part of the connecting pipe 742 is conveniently aligned with the fourth section liquid feeding hole 734; the large end column side surface part of the end head part 741 is embedded into the first section liquid conveying hole 731, meanwhile, the large end side surface is attached to the step surfaces of the first section liquid conveying hole 731 and the second section liquid conveying hole 732, and the aperture of the first section liquid conveying hole 731 is 0.1-0.5 mm larger than the large end outer diameter of the end head part 741.

Optionally, the inner hole of the seat 71 is screwed with the injection base 1, and the threads at this point and the threads at other parts of the injection device have the following effects: the screw thread sealing device is convenient to disassemble and assemble, can quickly complete component replacement when damaged or replaced, is reliable in screw thread sealing and is not easy to leak liquid medicine.

Optionally, an annular flange 75 is disposed on an outer side surface of one end of the base 71, which is close to the nozzle 3, and when the plunger 5 is pushed, force can be applied by the annular flange 75 in an auxiliary manner, so that the operation is facilitated. In addition, the base 71 may be a T-shaped sleeve structure, and the annular flange 75 is disposed at the end of the T-shaped head to increase the structural strength.

As shown in fig. 2 and 14, the front cover 9 is sleeved on the outer side surface of the nozzle 3, and the front cover 9 is cylindrical and can elastically stretch and retract along the axial direction of the injection base 1, so that the injection port 31 is retracted or exposed out of the end surface of the front cover 9. When not in use, the front cover 9 covers the injection port 31 and protects the injection port 31; during injection, the end face of the front cover 9 is contacted and attached with the area to be injected to form a flatter injection area, and then the end face of the injection outlet 31 of the nozzle 3 is attached with the injection area, so that the injection quality is improved.

Optionally, as shown in fig. 4 and 13, the front end of the injection matrix 1 is further provided with a baffle ring 15 formed by annular protrusions, the front cover 9 is in a T-shaped sleeve shape, the T-shaped end is close to the baffle ring 15, but has a certain distance, a plurality of slots 91 are formed in the end face of the T-shaped sleeve, a second spring 92 is placed in the slots 91, the second spring 92 is elastically compressed and supported between the front cover 9 and the baffle ring 15, and after the front cover 9 is stressed, the second spring 92 can be compressed to be attached to the baffle ring 15, so that shrinkage is realized, and the injection port 31 is exposed.

Optionally, the front end shaft diameter of the injection base 1 is smaller in a stepped shaft section 14, the stepped shaft section 14 is in threaded connection with a cover side wall 3022 of the injection end body 302, and the outer diameter of the cover side wall 3022 is larger than the outer diameter of the post body of the injection base 1, so that after the cover side wall 3022 is screwed on the stepped shaft section 14, the outer side surface is higher than the injection base 1, as shown in fig. 2, a stepped hole is formed in an inner hole of the front cover 9, and elastic floating limiting of the front cover 9 is formed.

When in operation, the device comprises: when the plunger 5 slides to the front end in the injection channel hole 2, the liquid medicine in the liquid inlet channel 6 is continuously compressed, after a certain pressure is reached, the check valve 4 is pushed open, the liquid medicine is ejected from the ejection port 31 at a high speed through the ejection channel 32 for injection, when the end face of the plunger 5 moves to the nozzle 3 for injection, and at the moment, the side face of the plunger 5 seals the liquid outlet 62; then, the plunger 5 slides to the rear end, and the injection channel 32 is blocked and disconnected due to the check valve 4, so that negative pressure is generated in the injection channel hole 2, and the liquid medicine in the liquid medicine container 8 enters the injection channel hole 2 through the liquid inlet channel 6 until the end of the plunger 5 passes over the liquid outlet 62 to the rear end, so that the liquid medicine is automatically replenished for the next injection.

The needleless injection system is simple and convenient to operate, simple in structure, capable of self-filling, designed to be replaceable, capable of easily replacing easily damaged parts such as the nozzle 3, capable of preventing suck-back, capable of performing high-efficiency injection, applicable to both needleless and needleless scenes, capable of being selected in various ways in power selection, and capable of being driven by a motor after manual pushing.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the scope of protection thereof, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that: various changes, modifications, or equivalents may be made to the particular embodiments of the invention by those skilled in the art after reading the present disclosure, but such changes, modifications, or equivalents are within the scope of the invention as defined in the appended claims.

Claims (10)

1. The utility model provides an injection device, its characterized in that includes the injection base member (1) of post shaft-like, it has injection passageway hole (2) that run through to open along the axis on injection base member (1), the one end of injection base member (1) is provided with nozzle (3), be provided with jet out mouth (31) and intercommunication on nozzle (3) jet out mouth (31) with injection passageway (32) of injection passageway hole (2), be provided with check valve (4) in jet out mouth (32), check valve (4) are used for control jet out mouth (32) are along jet out the direction unidirectional current, be provided with plunger (5) in injection passageway hole (2), plunger (5) follow injection passageway hole (2) are kept away from the one end slip of nozzle (3) is inserted, be equipped with feed liquor passageway (6) on the lateral wall of injection base member (1), feed liquor passageway (6) run through the lateral wall of injection base member (1) for to injection passageway hole (2) carry the liquid medicine that waits to apply.

2. An injection device according to claim 1, further comprising a rear seat (7), wherein the rear seat (7) comprises a sleeve-shaped seat body (71), the seat body (71) is sleeved on the outer side surface of one end of the injection substrate (1) far away from the nozzle (3), the side wall part of the seat body (71) protrudes outwards to form a columnar protruding structure (72), the included angle between the protruding structure (72) and the axis of the seat body (71) is an acute angle, a through liquid conveying channel hole (73) is formed in the rear seat (7) along the axis of the protruding structure (72), and a liquid medicine connecting piece (74) is arranged in the liquid conveying channel hole (73), and the liquid medicine connecting piece (74) is used for communicating a liquid medicine container (8) with the liquid conveying channel hole (73).

3. An injection device according to claim 2, wherein the liquid medicine connecting member (74) comprises a cylindrical end portion (741), a first connecting screw thread (7411) is provided on a small end cylindrical side surface of the end portion (741), the first connecting screw thread (7411) is used for connecting with a liquid medicine container (8), a connecting pipe (742) is provided on a large end surface of the end portion (741), the connecting pipe (742) and the end portion (741) are coaxially arranged, a first frustum body (743) and a second frustum body (744) are respectively formed by protruding outwards from the side surface of the connecting pipe (742), the first frustum body (743) is close to the end portion (741), the diameter of the conical bottom surface of the first frustum body (743) is larger than that of the second frustum body (744), a second connecting screw thread (7421) is provided on the outer side surface of the end portion of the connecting pipe (742), and a connecting hole (745) communicated with the connecting pipe (742) is provided in the axial direction of the end portion (741).

4. An injection device according to claim 3, wherein the liquid delivery passage hole (73) has a stepped hole structure, and comprises a first section liquid delivery hole (731), a second section liquid delivery hole (732), a third section liquid delivery hole (733) and a fourth section liquid delivery hole (734) which are sequentially arranged from outside to inside and have gradually reduced pore diameters; the first section liquid feeding hole (731) is embedded and matched with a large end cylinder of the end head part (741), the second section liquid feeding hole (732) is matched with the outer circle of the conical bottom of the first frustum body (743), the aperture of the third section liquid feeding hole (733) is smaller than the diameter of the conical bottom surface of the second frustum body (744), and the fourth section liquid feeding hole (734) is in threaded connection with the second connecting thread (7421).

5. An injection device according to claim 2, wherein the inner bore of the housing (71) is in threaded connection with the injection base (1), and wherein an annular flange (75) is provided on the outer side of the end of the housing (71) adjacent the nozzle (3).

6. An injection device according to claim 1, wherein the nozzle (3) comprises a dispensing end body (301) and a spraying end body (302), the dispensing end body (301) has a cylindrical disk shape, and an end face is arranged opposite to an end face Ji Tiege of the injection base body (1), and the dispensing end body (301) is provided with a first through hole (321) penetrating in the axial direction; the injection end body (302) is cylindrical cap-shaped, the cover is arranged on the outer side of the end portion of the distribution end body (301) and the end portion of the injection base body (1), the injection end body (302) comprises a cover plate (3021) and a cover side wall (3022), a first groove (322) is formed in the center of the inner side surface of the cover plate (3021), a second through hole (323) penetrating through the cover plate (3021) is formed in the axis, a port of the second through hole (323) is the injection port (31), the second through hole (323), an inner cavity of the first groove (322) and the first through hole (321) are mutually communicated to form the injection channel (32), and the connection position of the first groove (322) and the first through hole (321) is controlled to be opened and closed by the check valve (4).

7. An injection device according to claim 6, wherein the check valve (4) comprises a first spring (41) and a valve core (42) arranged in the first recess (322).

8. An injection device according to claim 6, wherein the dispensing end body (301) is provided with a second recess (3011) away from the centre of the end face of the injection base body (1), the inner side of the cover plate (3021) is provided with a first protrusion (3023) which is adapted to fit into the second recess (3011), a sealing ring (303) is provided between the end face of the first protrusion (3023) and the bottom surface of the second recess (3011), and the sealing ring (303) is used for sealing the communication between the inner cavity of the first recess (322) and the first through hole (321).

9. An injection device according to claim 6, wherein the outer side of the cover plate (3021) is centrally provided with a second protrusion (3024) in the form of a cone.

10. An injection device according to claim 6, wherein a front cover (9) is sleeved on the outer side surface of the nozzle (3), the front cover (9) is cylindrical and can elastically stretch and retract along the axial direction of the injection substrate (1), so that the injection port (31) is retracted or the end surface of the front cover (9) is exposed.