CN216974972U

CN216974972U - Liquid injection device

Info

Publication number: CN216974972U
Application number: CN202220922462.9U
Authority: CN
Inventors: 陈卫国
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-04-20
Filing date: 2022-04-20
Publication date: 2022-07-15
Anticipated expiration: 2032-04-20

Abstract

The application provides a priming device relates to machine oil filling technical field. A liquid injection device comprises a supporting component, a liquid injection component and an anti-backflow component, wherein the supporting component comprises a supporting plate, a liquid inlet hole and an air inlet hole are formed in the supporting plate, and the liquid inlet hole and the air inlet hole are not in contact with each other; the liquid injection component comprises a liquid injection pipe, and the liquid injection pipe is arranged at the liquid inlet; the backflow prevention assembly comprises a one-way valve, the one-way valve is arranged at the air inlet, and the liquid injection pipe is selectively connected with or separated from the one-way valve. The liquid injection device can accurately inject the engine oil without dripping and leaking, can avoid the condition of residual liquid pollution when the engine oil is injected, can recover the residual liquid, and is convenient to clean.

Description

Liquid injection device

Technical Field

The application relates to the technical field of engine oil filling, in particular to a liquid injection device.

Background

The engine oil filling port of part of the automobile type is positioned at the middle rear part of the engine, and the wiper cover plate and the water guide groove metal plate cover part of the filling space of the engine oil filling port, so that the difficulty of engine oil filling during maintenance of the automobile engine is caused. At present, the added engine oil is always poured directly by hand, oil leakage is easy to occur, waste is caused, the amount of the poured engine oil cannot be accurately measured, and certain inconvenience is caused in use; and original machine oil is difficult to the clean up when adding machine oil, and when filling machine oil again, new machine oil can be to a certain extent polluted by original machine oil, and the result of use of machine oil can reduce relatively.

SUMMERY OF THE UTILITY MODEL

An object of this application is to provide a priming device, it can be to the accurate filling that does not have the water clock of machine oil, can avoid causing the condition that the raffinate pollutes when machine oil is annotated to can retrieve the raffinate, convenient cleanness.

The embodiment of the application is realized as follows:

the embodiment of the application provides a liquid injection device, which comprises a supporting component, a liquid injection component and an anti-backflow component, wherein the supporting component comprises a supporting plate, a liquid inlet hole and an air inlet hole are formed in the supporting plate, and the liquid inlet hole and the air inlet hole are not in contact with each other; the liquid injection assembly comprises a liquid injection pipe, and the liquid injection pipe is arranged at the liquid inlet; the backflow-preventing assembly comprises a one-way valve, the one-way valve is arranged at the air inlet, and the liquid injection pipe can be selectively connected with or separated from the one-way valve.

In some embodiments of the present application, the liquid injection assembly further includes a liquid guide pipe, the liquid guide pipe is communicated with the liquid inlet hole, and the liquid injection pipe is sleeved on the liquid guide pipe.

In some embodiments of the application, the lateral wall of the flow guide pipe is provided with a limiting block.

In some embodiments of the present application, the number of the limiting blocks is plural, and the plurality of limiting blocks are circumferentially disposed on the outer side of the flow guide pipe to form a retaining ring.

In some embodiments of the present application, the supporting assembly further includes a base adapted to the supporting plate, the base is fixedly connected to the supporting plate, the base and the supporting plate are mutually matched to form a cover with an opening on one side, and the liquid injection assembly and the backflow prevention assembly are located outside the cover.

In some embodiments of the present application, the inner side of the flap is threaded.

In some embodiments of the present application, the backflow preventing assembly further includes a connection pipe, the connection pipe is communicated with the air inlet hole, and the check valve is detachably connected to the connection pipe.

In some embodiments of the present application, the connection tube is threadedly coupled to the flap.

In some embodiments of the present application, the liquid filling device further includes a residual liquid collector, the residual liquid collector is provided with an inlet pipe and an outlet pipe, and the inlet pipe is connected to the one-way valve.

In some embodiments of the present application, a residual liquid accommodating chamber is disposed in the residual liquid collector, two ends of the residual liquid accommodating chamber are respectively connected to the inlet pipe and the outlet pipe, and one end of the outlet pipe, which is close to the residual liquid accommodating chamber, is disposed in the residual liquid accommodating chamber.

Compared with the prior art, the embodiment of the application has at least the following advantages or beneficial effects:

1. the application provides a priming device it can avoid machine oil to add more or add fewly to the accurate filling that does not have the water clock of machine oil.

2. The liquid injection device is provided with the residual liquid collector, so that residual liquid can be recovered, and the situation of residual liquid pollution caused by filling of engine oil can be avoided.

3. The liquid injection device is simple in structure, low in cost, detachable in parts, convenient to install and clean.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

Fig. 1 is a schematic structural diagram of a liquid injection device in embodiment 1 of the present application without a check valve;

FIG. 2 is a cross-sectional view taken at A-A of FIG. 1;

FIG. 3 is a schematic structural diagram of a check valve in an embodiment of the present application;

FIG. 4 is a cross-sectional view taken at B-B of FIG. 3;

fig. 5 is a schematic structural diagram of an injection device in embodiment 2 of the present application;

FIG. 6 is a schematic view showing the structure of a residue collector in the embodiment of the present application.

Icon: 101. a flap; 102. a liquid inlet hole; 103. an air inlet hole; 201. a liquid injection pipe; 202. a flow guide pipe; 203. a limiting block; 301. a one-way valve; 302. a connecting pipe; 303. a threaded connection; 304. an open large end; 305. an open small end; 306. a spring; 401. an inlet pipe; 402. an outlet pipe; 403. a residual liquid accommodating chamber.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "inner", "outer", etc. are used for indicating the orientation or positional relationship based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship which is usually arranged when the product of the application is used, the description is only for convenience and simplicity, but the indication or suggestion that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, cannot be understood as the limitation of the application.

In the description of the embodiments of the present application, "a plurality" means at least 2.

In the description of the embodiments of the present application, it should be further noted that unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

Example 1

Referring to fig. 1 to 5, the present embodiment provides a liquid injection device, which may include a supporting assembly, a liquid injection assembly, and a backflow prevention assembly, where the supporting assembly includes a supporting plate, the supporting plate is provided with a liquid inlet hole 102 and an air inlet hole 103, and the liquid inlet hole 102 and the air inlet hole 103 are not in contact with each other; the liquid injection assembly comprises a liquid injection pipe 201, and the liquid injection pipe 201 is arranged at the liquid inlet hole 102; the backflow prevention assembly includes a check valve 301, the check valve 301 is disposed at the air inlet hole 103, and the injection pipe 201 is selectively connected to or separated from the check valve 301.

When the automobile engine oil filling device is used, the free end of the liquid injection pipe 201 is placed in an engine oil box of an automobile, the supporting plate is abutted against the opening of a purchased engine oil bottle, the opening of the engine oil bottle faces downwards, and therefore engine oil can flow into the liquid injection pipe 201 through the liquid inlet hole 102; meanwhile, air flows into the engine oil bottle through the one-way valve 301, so that pressure difference is formed in the engine oil bottle, and engine oil is injected into an engine oil tank of the automobile; the check valve 301 is provided for the purpose of allowing air to flow only in the direction indicated by the arrow in fig. 5, and when the oil bottle is inverted, oil flows only into the liquid-pouring spout 201 through the liquid inlet hole 102, but does not flow out through the air inlet hole 103. In addition, when the engine oil is filled, the engine oil level at the opening of the engine oil tank can be concerned, whether the engine oil is filled is judged, and if the engine oil is filled, the engine oil filling can be stopped; after the engine oil is filled, the capacity of the engine oil tank of the automobile can be judged by observing the residual engine oil amount in the engine oil bottle, so that the next accurate filling is facilitated, and the condition that the engine oil is overflowed due to the fact that the engine oil is overflowed because the capacity of the engine oil tank is unknown, and the residual liquid pollution is caused is avoided. The liquid injection device can accurately inject the engine oil without dripping and leaking, and can avoid the condition of residual liquid pollution when the engine oil is injected; the liquid injection device is simple in structure, low in cost, detachable in parts, convenient to install and clean.

In this embodiment, the liquid injection assembly further includes a liquid guide pipe 202, the liquid guide pipe 202 is communicated with the liquid inlet hole 102, and the liquid injection pipe 201 is sleeved on the liquid guide pipe 202.

The diameter of honeycomb duct 202 is greater than or equal to the diameter of feed liquor hole 102, and honeycomb duct 202 fixed connection is on the backup pad to honeycomb duct 202 and feed liquor hole 102 intercommunication each other, honeycomb duct 202 plays the effect of drainage, makes in the machine oil can accurately flow into annotates liquid pipe 201. When the engine oil injection device is used, one end of the injection pipe 201 is sleeved on the flow guide pipe 202, and the other end of the injection pipe is placed in an engine oil box of an automobile, so that the engine oil can flow into the injection pipe 201 along the extending direction of the flow guide pipe 202, and the engine oil is injected into the engine oil box. The design of adding the honeycomb duct 202 is convenient for drainage on one hand, and on the other hand, in order to enable the liquid injection pipe 201 to be detached from the liquid injection device, after the oil injection is finished, the liquid injection pipe 201 can be taken down separately for cleaning, so that the residual oil of the oil is prevented from remaining in the liquid injection pipe 201 to influence the secondary injection; in addition, the machine oil case size of some cars is great, needs longer or the bigger notes liquid pipe 201 of diameter, annotates liquid pipe 201 and can dismantle with honeycomb duct 202 and be connected, is convenient for change the notes liquid pipe 201 of different length or diameter to be suitable for different filling environment, the more accurate completion machine oil filling of rapider.

In this embodiment, the outer side wall of the flow guide tube 202 is provided with a limiting block 203.

The stopper 203 is triangular protrusion, and annotate the liquid pipe 201 and be the plastic hose, and when annotating liquid pipe 201 cover and locate the honeycomb duct 202 outside, the bellying of stopper 203 contacts with annotating liquid pipe 201 inner wall, and the stopper 203 mainly makes the cover that annotates liquid pipe 201 can stabilize locate on honeycomb duct 202. When carrying out the machine oil filling, machine oil bottleneck and backup pad butt, the bottleneck is down, honeycomb duct 202 also adds bellied design with annotating liquid pipe 201 down, can make this priming device when carrying out the machine oil filling, annotates the cover that liquid pipe 201 can stabilize and locates the honeycomb duct 202 lateral wall, can not separate with it, has strengthened greatly and has annotated the stability of being connected of liquid pipe 201 and honeycomb duct 202.

In this embodiment, the number of the stoppers 203 is plural, and the plural stoppers 203 are circumferentially disposed on the outer side of the flow guide tube 202 to form a non-return ring.

The anti-return ring is arranged outside the circumference of the draft tube 202, the liquid injection tube 201 is a plastic hose with certain flexibility, and the diameter of the anti-return ring is slightly larger than that of the liquid injection tube 201. When the liquid injection pipe 201 is sleeved on the outer side wall of the draft tube 202, the liquid injection pipe 201 is in contact with the anti-return ring, and the diameter of the anti-return ring is slightly larger than that of the liquid injection pipe 201, so that the anti-return ring can firmly clamp the liquid injection pipe 201 and prevent the liquid injection pipe 201 from being separated from the draft tube 202. The number of the retaining rings is not limited in the present application, and may be, for example, 3, 4, or 5, as long as the pouring spout 201 can be firmly locked. In addition, a plurality of anti-return rings are arranged on the outer circumference of the guide pipe 202 at intervals in parallel, so that a groove is formed between every two adjacent anti-return rings, the groove can contain air existing at the connecting part of the guide pipe 202 and the liquid injection pipe 201 or residual oil of engine oil which flows into the groove carelessly, and the anti-return rings can enable the liquid injection pipe 201 and the guide pipe 202 to be connected more stably.

In this embodiment, the supporting assembly further includes a base adapted to the supporting plate, the base is fixedly connected to the supporting plate, the base and the supporting plate are matched with each other to form a cover 101 having an opening on one side, and the liquid injection assembly and the backflow prevention assembly are located outside the cover 101.

Base and backup pad fixed connection back, base and backup pad mutually support and form a flap 101, because of base and backup pad are fixed connection, consequently when carrying out machine oil filling, base and backup pad are fixed an organic whole, even receive under the effect of external force, can not separate each other yet, have increased the security of using. In addition, flap 101 and machine oil bottleneck interconnect, backup pad and the machine oil bottleneck looks adaptation on the flap 101, and backup pad and machine oil bottleneck butt, like this when machine oil filling, even the body is invertd, the bottleneck is down, and machine oil can not overflow outside the port lid 101 yet. The oil in the oil bottle flows into the liquid injection pipe 201 through the liquid inlet hole 102 on the cover 101, and then flows into the oil tank to be filled with the oil.

In this embodiment, the inside of the flap 101 is threaded.

The cover 101 is in threaded connection with the oil bottle, after the oil is filled, the cover 101 can be unscrewed from the oil bottle opening and cleaned, and meanwhile, the cover 101 is convenient to connect with the oil bottle. In addition, flap 101 and machine oil bottle threaded connection also can avoid at the in-process that machine oil was filled, and machine oil spills over and causes the machine oil extravagant.

The diameter of the cover 101 may be determined according to the size of the oil tank, and may be 10cm, 20cm, 30cm, or the like, which is not limited in the present application.

In this embodiment, the backflow prevention assembly further includes a connection pipe 302, the connection pipe 302 communicates with the air inlet hole 103, and the check valve 301 is detachably connected to the connection pipe 302.

The connecting pipe 302 is connected with the air inlet hole 103, and the diameter of the connecting pipe 302 is larger than or equal to the diameter of the air inlet hole 103, so that air can enter the liquid injection device conveniently. When the oil filling device is used, the cover cap 101 is in threaded connection with the opening of the oil bottle, the oil bottle body is arranged on the oil filling device, and the cover cap 101 is positioned below the oil bottle, namely, the oil bottle is in an inverted state when oil is filled; when machine oil filling, the machine oil bottle is the state that is zonulae occludens with flap 101, and the air flows in behind flap 101, can form the pressure difference in the flap 101, under the effect of pressure difference, machine oil alright in order to flow into notes liquid pipe 201 through the inlet on the flap 101, the free end of annotating liquid pipe 201 is placed in advance in the machine oil tank that needs the machine oil of maring, and machine oil in annotating liquid pipe 201 like this can be along with annotating the extending direction of liquid pipe 201 and flow in the machine oil tank of car.

The length of the liquid injection pipe 201 may be 50cm, 100cm, 200cm, etc., and may be determined according to the specific size of the engine oil tank, which is not limited in this application; in addition, annotate the diameter of liquid pipe 201 and also decide the concrete size of machine oil case, do not do the injecing to this application, the diameter of inlet and honeycomb duct 202 can carry out corresponding adjustment according to annotating the diameter size of liquid pipe 201 simultaneously, makes inlet, honeycomb duct 202 and annotate liquid pipe 201 three looks mutual adaptation.

In this embodiment, the connection tube 302 is threadedly coupled to the flap 101.

As shown in fig. 2, threaded connection portion 303 has been seted up to air inlet hole 103 department in flap 101, be equipped with the screw thread in this threaded connection portion 303, can be used to connecting pipe 302 and flap 101 to carry out threaded connection, the external screw thread has all been seted up at the both ends of this connecting pipe 302, the one end of connecting pipe 302 links to each other with this threaded connection portion 303, the other end and the check valve 301 threaded connection of connecting pipe 302, connecting pipe 302 and flap 101 and check valve 301 each other are connected for dismantling like this, easy to assemble and dismantlement, it washs each spare part to also make things convenient for machine oil to annotate after accomplishing simultaneously.

Example 2

Referring to fig. 5 to 6, the liquid injection device provided in this embodiment is substantially the same as that in embodiment 1, except that the liquid injection device further includes a residual liquid collector, the residual liquid collector is provided with an inlet pipe 401 and an outlet pipe 402, and the inlet pipe 401 is connected to the check valve 301.

The residual liquid collector is used for conveniently collecting residual liquid so as to avoid residual liquid pollution and also can recycle the residual liquid. When the check valve 301 is used, the check valve 301 is attached to the air inlet hole 103, so that the oil can be prevented from flowing out from the air inlet hole 103 when the oil is filled, but if the check valve 301 is broken, the oil can inevitably flow out from the air inlet hole 103. Therefore, in use, the open large end 304 of the check valve 301 is connected to the free end of the connection pipe 302, and the open small end 305 is connected to the inlet pipe 401 of the residual liquid collector, so that even if the check valve 301 is broken and oil leaks, the oil does not directly overflow but flows into the residual liquid collector to be stored.

The inside spring 306 that is provided with of check valve 301, push rod and spacer, spring 306 is located on the push rod, one side that spring 306 is close to opening tip 305 butts with the spacer, like this, when carrying out the machine oil filling, because of the opening tip 304 of check valve 301 is connected with the free end of connecting pipe 302, therefore the opening tip 305 of check valve 301 is located the lower part of opening tip 304, when machine oil passes through the air inlet in flap 101, can promote the spacer downward movement, the spacer moves to the through-hole department of opening tip 305 and stops like this, this through-hole and spacer looks adaptation, therefore machine oil just can not flow out from the opening tip 305 of this check valve 301, this check valve 301 plays the effect of current-limiting to machine oil.

It should be noted that the check valve 301 shown in the drawings of the present application is only one embodiment of the present embodiment, and other types of check valves 301 may be used as long as the oil can flow in one direction and cannot flow out of the check valve 301, and the present application is not limited thereto.

In this embodiment, a residual liquid containing chamber 403 is disposed in the residual liquid collector, two ends of the residual liquid containing chamber 403 are respectively connected to the inlet pipe 401 and the outlet pipe 402, and one end of the outlet pipe 402 close to the residual liquid containing chamber 403 is disposed in the residual liquid containing chamber 403.

The residual liquid containing chamber 403 is used for storing residual oil of engine oil, and one end of the outlet pipe 402 close to the residual liquid containing chamber 403 is arranged in the residual liquid containing chamber 403, so that leaked engine oil flows out towards the outlet pipe 402 of the residual liquid collector along the inner wall of the residual liquid collector, and the part of the outlet pipe 402 in the residual liquid containing chamber 403 has a function of blocking the residual oil of engine oil, and the residual oil of engine oil can be prevented from flowing out from the outlet pipe 402 of the residual liquid collector.

When the amount of the residual oil is small, the residual oil does not easily flow out of the residual oil containing chamber 403, and a small amount of residual oil can be stored; only when the oil residue overflows to a certain amount will it flow out through the residue collector outlet 402.

The size of raffinate holding chamber 403 is greater than the diameter of outlet pipe 402 and inlet pipe 401, consequently, flow from the opening tip 305 of check valve 301 as the raffinate, when inlet pipe 401 of rethread raffinate collector flowed into raffinate holding chamber 403, the raffinate can not directly drop towards the outlet pipe 402 of raffinate collector, but can flow to the outlet pipe 402 department of raffinate collector along the inner wall of raffinate holding chamber 403, outlet pipe 402 of raffinate collector has a part to set up in raffinate holding chamber 403, consequently, the raffinate that flows along the inner wall of raffinate holding chamber 403 can stop in the recess that outlet pipe 402 of raffinate collector and raffinate holding chamber 403 mutually supported and form, store the raffinate.

After filling, all the parts can be detached, cleaned individually, and then assembled after cleaning, because the liquid filling pipe 201 is a plastic hose and has certain flexibility, when the liquid filling device is not used, the free end of the liquid filling pipe 201 can be inserted into the small opening end 305 of the one-way valve 301; if the opening tip 305 of check valve 301 is connected with the raffinate collector, can insert the outlet pipe 402 department of raffinate collector with the free end of this notes liquid pipe 201, make things convenient for accomodating of this priming device like this, also avoid annotating the raffinate in the liquid pipe 201 and spill over, cause the pollution.

It should be noted here that, the priming device that this application provided not only can be used for the filling of machine oil, can also be used for the filling of other liquid, has advantages such as extensive applicability, practicality are strong.

In summary, the embodiment of the application provides a liquid injection device, which comprises a support assembly, a liquid injection assembly and an anti-backflow assembly, wherein the support assembly comprises a support plate, a liquid inlet hole 102 and an air inlet hole 103 are formed in the support plate, and the liquid inlet hole 102 and the air inlet hole 103 are not in contact with each other; the liquid injection assembly comprises a liquid injection pipe 201, and the liquid injection pipe 201 is arranged at the liquid inlet hole 102; the backflow prevention assembly includes a check valve 301, the check valve 301 is disposed at the air inlet hole 103, and the injection pipe 201 is selectively connected to or separated from the check valve 301.

When the automobile engine oil filling device is used, the liquid injection pipe 201 is placed in an engine oil box of an automobile, the supporting plate is abutted against the opening of a purchased engine oil bottle, the opening of the engine oil bottle faces downwards, and therefore engine oil can flow into the liquid injection pipe 201 through the liquid inlet hole 102; meanwhile, air flows into the engine oil bottle through the one-way valve 301, so that pressure difference is formed in the engine oil bottle, and engine oil is injected into an engine oil tank of the automobile; the check valve 301 is provided for the purpose of allowing air to flow only in the direction indicated by the arrow in fig. 5, and when the oil bottle is inverted, oil flows only into the liquid-pouring spout 201 through the liquid inlet hole 102, but does not flow out through the air inlet hole 103. In addition, when the engine oil is filled, the engine oil level at the opening of the engine oil tank can be concerned, whether the engine oil is filled is judged, and if the engine oil is filled, the engine oil filling can be stopped; after the engine oil is filled, the capacity of the engine oil tank of the automobile can be judged by observing the residual engine oil amount in the engine oil bottle, so that the next accurate filling is facilitated, and the condition that the engine oil is overflowed due to the fact that the engine oil is overflowed because the capacity of the engine oil tank is unknown, and the residual liquid pollution is caused is avoided.

The liquid injection device can accurately inject the engine oil without dripping and leaking, and can avoid the condition of residual liquid pollution when the engine oil is injected; the liquid injection device is simple in structure and low in cost, and each part can be detached and is convenient to mount and clean; the liquid injection device is provided with a residual liquid collector, so that residual liquid can be recovered, and the phenomenon that the residual liquid overflows to cause pollution is avoided; when the liquid injection device is not used, the free end of the liquid injection pipe 201 can be inserted into the small opening end 305 of the one-way valve 301; if the small opening end 305 of the check valve 301 is connected with a residual liquid collector, the free end of the liquid injection pipe 201 can be inserted into the outlet pipe 402 of the residual liquid collector, so that the liquid injection device is convenient to store, and the residual liquid in the liquid injection pipe 201 is prevented from overflowing to cause pollution.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A priming device, comprising:

the supporting component comprises a supporting plate, the supporting plate is provided with a liquid inlet hole and an air inlet hole, and the liquid inlet hole and the air inlet hole are not contacted with each other;

the liquid injection assembly comprises a liquid injection pipe, and the liquid injection pipe is arranged at the liquid inlet;

the backflow prevention assembly comprises a one-way valve, the one-way valve is arranged at the air inlet, and the liquid injection pipe is selectively connected with or separated from the one-way valve.

2. The liquid injection device according to claim 1, wherein the liquid injection assembly further comprises a liquid guide pipe, the liquid guide pipe is communicated with the liquid inlet hole, and the liquid injection pipe is sleeved on the liquid guide pipe.

3. The liquid injection device according to claim 2, wherein a limiting block is disposed on an outer side wall of the flow guide pipe.

4. The liquid injection device according to claim 3, wherein the number of the limiting blocks is plural, and the plurality of limiting blocks are circumferentially arranged outside the flow guide pipe to form a stop ring.

5. The liquid injection device according to claim 1, wherein the support assembly further comprises a base adapted to the support plate, the base is fixedly connected to the support plate, the base and the support plate cooperate with each other to form a cover with an opening at one side, and the liquid injection assembly and the backflow prevention assembly are located outside the cover.

6. The filling device of claim 5, wherein the inner side of the flap is threaded.

7. The fluid injection apparatus according to claim 6, wherein the backflow prevention assembly further comprises a connection pipe, the connection pipe is communicated with the air inlet hole, and the one-way valve is detachably connected to the connection pipe.

8. The filling device of claim 7, wherein the connecting tube is threadably connected to the port cover.

9. The liquid injection device according to claim 1, further comprising a residual liquid collector, wherein the residual liquid collector is provided with an inlet pipe and an outlet pipe, and the inlet pipe is connected with the one-way valve.

10. The liquid injection device according to claim 9, wherein a residual liquid accommodating chamber is provided in the residual liquid collector, two ends of the residual liquid accommodating chamber are respectively connected to the inlet pipe and the outlet pipe, and one end of the outlet pipe close to the residual liquid accommodating chamber is disposed in the residual liquid accommodating chamber.