CN204307149U - Closed positive pressure remaining needle - Google Patents

Abstract

The utility model discloses a closed positive pressure indwelling needle, which comprises a needle head, a positive pressure joint, a closed joint, and a connecting pipeline. The closed joint includes a first liquid outlet end, a first liquid inlet end, a first The infusion channel and the first elastic sealing plug, the first elastic sealing plug has a first slit, the first elastic sealing plug isolates the first infusion channel from the outside world, and bacteria or dust cannot enter the liquid from the first The connector enters, so that the closed positive pressure indwelling needle can be used for a long time. When injecting liquid, a needle-free infusion set can be used to squeeze in through the first slit to inject liquid, thus avoiding the pressure caused by the steel needle. In addition, when the connector of the infusion set is pulled out from the second liquid inlet end of the positive pressure connector, the inner cavity of the positive pressure connector is in contact with the second liquid end of the positive pressure connector. The volume of the part connected to the two liquid outlets is reduced to generate a positive pressure to the second liquid outlet to avoid blood back phenomenon.

Description

Closed positive pressure indwelling needle

technical field

The utility model relates to the technical field of medical instruments, in particular to a closed positive pressure indwelling needle.

Background technique

The venous indwelling needle is also called the venous trocar. The core components include a soft catheter/cannula that can be indwelled in the blood vessel, and a stainless steel puncture guide core. When used, the catheter and the needle core are punctured into the blood vessel together. After the catheter is fully inserted into the blood vessel, the needle core is withdrawn, and only the soft catheter is left in the blood vessel for infusion therapy.

The use of intravenous indwelling needles can reduce the pain caused by repeated venipuncture and the fear of injections in children, relieve the anxiety of parents, facilitate clinical medication, rescue medication for acute and critical patients, reduce the workload of nurses, and reduce the risk of children's anxiety. Pain, so intravenous indwelling needles are widely used clinically. Facing the special group of children, the indwelling time of intravenous indwelling needles and the comfort of children have become the most concerned issues for nurses and parents, and they are also the symbol and promotion of the successful use of indwelling needles. premise.

At present, the indwelling needles commonly used in the industry include open indwelling needles and closed positive pressure indwelling needles. Among them, the open indwelling needles usually use a protective cap to cover the liquid inlet connector of the liquid inlet connector to protect the indwelling needle. During use, first take off the protective cap and connect the connector of the infusion set with the liquid inlet connector, however, after the protective cap is removed and before the connector of the infusion set is inserted into the liquid inlet connector, bacteria or dust are easy to come from The liquid inlet joint enters and contaminates the open indwelling needle, so that the open indwelling needle cannot be used for a long time.

The difference between the closed indwelling needle and the open indwelling needle is that the liquid inlet connector of the closed indwelling needle is equipped with a heparin cap. When using it, it is not necessary to remove the heparin cap, but to pass through the infusion set with a steel needle. A connector is pierced through the heparin cap into the inlet connector. However, the infusion sets using steel needles have risks mainly in that during use, medical personnel may take unsterilized steel needles that have been used by others by mistake, so that patients have the risk of infecting blood diseases, and, The steel needle may generate fine debris during the process of passing through the heparin cap, and the fine debris may enter the patient's vein during the puncture process along with the infusion or blood transfusion. After use, the steel needle sticking with the patient's blood may pierce the medical staff , causing medical staff to have the risk of infecting blood diseases, that is, there is a risk of infecting blood diseases among patients and medical staff with steel needles.

In addition, there is another problem in the use of the above-mentioned open indwelling needle and closed positive pressure indwelling needle: when the connector of the infusion set is pulled out from the liquid inlet end of the liquid inlet connector, the inner cavity of the liquid inlet connector may be The phenomenon that the volume becomes larger and negative pressure is generated, which leads to blood return.

Utility model content

The main purpose of this utility model is to solve the problem that bacteria or dust enter from the liquid inlet joint of the open indwelling needle, so that the open indwelling needle needs to be replaced frequently, and the sealed indwelling needle needs to use an infusion set with a steel needle, and the existence of the steel needle makes Patients and medical staff have the risk of infecting blood diseases, and when the connector of the infusion set is pulled out from the liquid inlet end of the liquid inlet connector, there is a problem of blood returning.

In order to achieve the above technical purpose, the utility model provides a closed positive pressure indwelling needle, the closed positive pressure indwelling needle includes a needle head, a positive pressure joint, a closed joint, and a connecting pipeline, and the closed joint includes a first liquid outlet connected to the connecting pipeline, a first liquid inlet used to connect with the connector of the infusion set, a first infusion channel passing through the first liquid inlet and the first liquid outlet, And the first elastic sealing plug arranged in the first infusion channel, from the end of the first elastic sealing plug facing the first liquid inlet to the end of the first elastic sealing plug facing away from the first A first slit is formed on the end surface of a liquid inlet end, and the first slit has a closed state of being squeezed and closed by the main body of the first elastic sealing plug, and is used for the joint of the infusion set to squeeze through. The open state communicated with the first liquid outlet.

Preferably, the closed joint includes a first male joint and a first female joint fixedly connected to the first male joint, the first male joint includes a first male joint main body, and is located on the first male joint main body. The first liquid outlet at one end of the main body, the first plug-in end at the other end of the first male connector body, and the first male connector passing through the first liquid outlet and the first plug-in end Inner cavity, the first female connector includes a first female connector body, the first liquid inlet end at one end of the first female connector body, and a first sleeve at the other end of the first female connector body Connecting end, and the inner chamber of the first female connector passing through the first liquid inlet end and the first sleeve end, the first insertion end of the first male connector is connected from the first sleeve of the first female connector The connecting end is socketed with the inner cavity of the first female joint, the first elastic sealing plug is installed in the inner cavity of the first female joint, and the back of the first elastic sealing plug faces the first liquid inlet The end face of the end abuts against the end face of the first plug-in end of the first male connector.

Preferably, the first male joint and the first female joint are fixedly connected by ultrasonic welding.

Preferably, on the end surface of the first plug-in end of the first male connector, a ring-shaped limiting part is protruded around the port of the inner cavity of the first male connector, and a limiting space is formed inside the ring-shaped limiting part, so that An end of the first elastic sealing plug away from the first liquid inlet end is accommodated and limited in the limiting space.

Preferably, the connecting pipeline includes a three-way tube, a one-way tube connecting one port of the three-way tube to the needle, and the other two ports of the three-way tube are connected to the positive pressure joint and the Closed connector connection.

Preferably, the positive pressure connector includes a second liquid outlet connected to the connecting pipeline, a second liquid inlet used to connect with the connector of the infusion set, and passes through the second liquid outlet and the first liquid outlet. A second infusion channel provided at the liquid inlet, a valve core and a core seat arranged in the second infusion channel, the second infusion channel includes a first cylindrical cavity provided through the second liquid inlet, And the first communication cavity provided through the second liquid outlet, the core seat is arranged in the first communication cavity, and the core seat has a second cylindrical cavity facing the first cylindrical cavity. chamber, a first section that is sealed and slidably connected with the first cylindrical chamber, and a second section that is sealed and slidably connected with the second cylindrical chamber, and the valve core is connected with the second cylindrical chamber The bottom is connected by a connecting spring, and the valve core is used to reduce the volume of the part of the second liquid infusion channel communicating with the second liquid outlet when moving toward the second liquid inlet end, so as to generate The forward pressure of the second liquid outlet.

Preferably, the positive pressure connector includes a second male connector and a second female connector fixedly connected to the second male connector, and the second male connector includes a second male connector body located on the second male connector body. The second liquid outlet at one end of the body, the second insertion end at the other end of the second male connector main body, and the second male connector inner cavity provided through the second liquid outlet, the first The second female joint includes a second female joint main body, the second liquid inlet end located at one end of the second female joint main body, a second sleeve end located at the other end of the second female joint main body, and The inner cavity of the second female joint of the second liquid inlet end and the second sleeve end, the second female joint inner cavity includes the first cylindrical cavity, and the installation device set through the second sleeve end. cavity, the core seat is integrally formed with the second plug-in end of the second male connector, and the second plug-in end of the second male connector is formed from the second sleeve end of the second female connector and the The sleeve is installed, and the core seat is accommodated in the installation cavity, and a communication hole is opened inside the core seat to communicate the inner cavity of the second male joint with the installation cavity.

Preferably, the second liquid inlet end is equipped with a second elastic sealing plug, from the end of the second elastic sealing plug facing the second liquid inlet end to the side of the second elastic sealing plug facing away from the A second slit is provided on the end surface of the second liquid inlet end, the second slit has a closed state of being squeezed and closed by the main body of the second elastic sealing plug, and is used for the joint of the infusion set to squeeze into A stretched state that passes through and communicates with the second liquid outlet.

Preferably, the second male connector and the second female connector adopt a snap-fit structure and a sealing ring to achieve a fixed and sealed connection.

The utility model provides a closed positive pressure indwelling needle. The closed positive pressure indwelling needle includes a needle head, a positive pressure joint, a closed joint, and a connecting pipeline. The closed joint includes a needle connected to the connecting pipeline. The first liquid outlet end, the first liquid inlet end used to connect with the joint of the infusion set, the first infusion channel passing through the first liquid inlet end and the first liquid outlet end, and the first The first elastic sealing plug in the infusion channel has an opening from the end face of the first elastic sealing plug facing the first liquid inlet end to the end face of the first elastic sealing plug facing away from the first liquid inlet end. The first slit, the first slit has a closed state of being squeezed and closed by the main body of the first elastic sealing plug, and is used for the joint of the infusion set to squeeze through to be connected with the first In the stretched state where the liquid outlet is connected, the first elastic sealing plug isolates the first infusion channel from the outside world, and bacteria or dust cannot enter through the first liquid inlet joint, thus making the closed positive pressure indwelling needle It can be used for a long time, and when injecting liquid, a needle-free infusion set can be used to squeeze through the first slit for injecting liquid, thus avoiding the problem of the risk of blood disease infection caused by steel needles to patients and medical staff , in addition, when the connector of the infusion set is pulled out from the second liquid inlet end of the positive pressure connector, the volume of the part of the inner cavity of the positive pressure connector communicated with the second liquid outlet port decreases, resulting in a The positive pressure of the second liquid outlet is mentioned to avoid the phenomenon of blood back.

Description of drawings

Fig. 1 is a structural schematic diagram of an embodiment of the closed positive pressure indwelling needle provided by the present invention;

Fig. 2 is a partial structural schematic diagram of the closed positive pressure indwelling needle shown in Fig. 1;

Fig. 3 is a schematic cross-sectional structural view of the closed joint of the closed positive pressure indwelling needle shown in Fig. 1;

Fig. 4 is a schematic cross-sectional structural view of the positive pressure joint of the closed positive pressure indwelling needle shown in Fig. 1 .

The realization of the purpose of the utility model, functional characteristics and advantages will be further described in conjunction with the embodiments and with reference to the accompanying drawings.

Detailed ways

The technical solution of the utility model is further described below in conjunction with the accompanying drawings and specific embodiments of the description. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

The utility model provides a closed positive pressure indwelling needle. In an embodiment of the closed positive pressure indwelling needle provided by the utility model in FIGS. 1 to 4, the closed positive pressure indwelling needle 100 includes a needle head 1, Type connector 2, positive pressure connector 3, and connecting pipeline 4, the closed connector 2 includes a first liquid outlet 21 connected with the connecting pipeline 4, a first inlet for connecting with the connector of the infusion set The liquid end 22, the first infusion channel 23 passing through the first liquid inlet end 22 and the first liquid outlet end 21, and the first elastic sealing plug 24 arranged in the first infusion channel 23, from the The end face of the first elastic sealing plug 24 facing the first liquid inlet 22 has a first slit 241 on the end face of the first elastic sealing plug 24 facing away from the first liquid inlet 22 , The first slit 241 has a closed state (as shown in FIG. 3 ) which is squeezed and closed by the main body of the first elastic sealing plug 24 , and is used for the joint of the infusion set to squeeze in and pass through to communicate with the infusion set. The open state in which the first liquid outlet 21 communicates (not shown).

When in use, the needle 1 of the airtight positive pressure indwelling needle 100, specifically the flexible tube of the needle 1, is left in the patient's body, before the liquid injection, that is, before the connector of the infusion set is inserted into the first liquid inlet port 22 , the first slit 241 is squeezed and closed by the main body of the first elastic sealing plug 24, so that the first infusion channel 23 is isolated from the outside world, and bacteria and dust cannot pass through the first liquid inlet port 22. into the first infusion channel 23, thus making the closed positive pressure indwelling needle 100 usable for a long time.

During liquid injection, the (tapered) joint of the needle-free liquid injector can be used to squeeze through the first slit 241 and communicate with the first infusion channel 23 for liquid injection, thus avoiding the injection caused by the steel needle. issues that put patients and healthcare workers at risk of contracting blood disorders. Moreover, during the injection process, the first elastic sealing plug 24 is engaged with the joint of the needle-free injector, so that the first infusion channel 23 is still isolated from the outside world, and bacteria and dust cannot come from the first infusion channel. A liquid inlet 22 enters the first infusion channel 23 .

Preferably, the first elastic sealing plug 24 is made of silica gel. In addition, in this embodiment, from the end of the first elastic sealing plug 24 facing away from the first liquid inlet end 22 to the first An elastic sealing plug 24 is concavely provided with a relief groove 242 on the end surface facing the first liquid inlet end 22, during the process of squeezing the first elastic sealing plug 24 into the first infusion channel 23, the The main body of the first elastic sealing plug 24 is deformed into the relief groove 242 for easy installation, and the first slit 241 is provided through the bottom of the relief groove 242 . The first slit 241 is a straight slit or a cross-shaped slit.

Please refer to FIGS. 2 to 3. In this embodiment, the closed joint 2 adopts a two-piece structure to facilitate molding. Specifically, the closed joint 2 includes a first male joint 201 and a A male connector 201 is fixedly connected to a first female connector 202 . Wherein, the first male connector 201 includes a first male connector body 201a, the first liquid outlet 21 located at one end of the first male connector body 201a, and the first liquid outlet end 21 located at the other end of the first male connector body 201a The first plug end 201b of the first outlet end 201b, and the first male connector cavity 201c passing through the first liquid outlet end 21 and the first plug end 201b, the first female connector 202 includes a first female connector body 202a , the first liquid inlet end 22 located at one end of the first female connector main body 202a, the first sleeve end 202b located at the other end of the first female connector main body 202a, and the first liquid inlet port that passes through the first female connector main body 202a end 22 and the first female connector cavity 202c of the first socket end 202b, the first socket end 201b of the first male connector 201 is connected from the first socket end 202b of the first female connector 202 The inner cavity 202c of the first female connector is socketed, and the inner cavity 201c of the first male connector communicates with the inner cavity 202c of the first female connector to form the first infusion channel 23, and the first male connector 201 and the first female connector 202 are fixedly connected by ultrasonic welding. The first elastic sealing plug 24 is installed in the inner cavity 202c of the first female joint, and the end surface of the first elastic sealing plug 24 facing away from the first liquid inlet 22 is in contact with the first male joint 201 The end surface of the first plug-in end 201b is abutted against.

In addition, on the end surface of the first plug-in end 201b of the first male connector 201, an annular limiting portion 201d protrudes around the port of the inner cavity 201c of the first male connector, and the inner side of the annular limiting portion 201d forms a There is a limiting space (not labeled), and the end of the first elastic sealing plug 24 away from the first liquid inlet 22 is accommodated and limited in the limiting space.

In this embodiment, the connecting pipeline 4 includes a three-way pipe 42, a one-way pipe 41 connecting one port of the three-way pipe 42 to the needle 1, and the other two ports of the three-way pipe 42 It is connected with the positive pressure joint 3 and the closed joint 2 .

Please refer to Figure 2 and Figure 4, in this embodiment, the positive pressure connector 3 includes a second liquid outlet 31 connected to the connecting pipeline 4, a second liquid inlet for connecting with the connector of the infusion set end 32, the second infusion channel 33 set through the second liquid outlet end 31 and the second liquid inlet end 32, the valve core 34 and the core seat 35 arranged in the second infusion channel 33, the The second infusion channel 33 includes a first cylindrical cavity 331 set through the second liquid inlet end 32, and a first communication cavity 332 set through the second liquid outlet end 31, the core seat 35 is set on the In the first communication cavity 332, the core base 35 has a second cylindrical cavity 351 facing the first cylindrical cavity 331, a first section that is sealed and slidably connected with the first cylindrical cavity 331 341, and the second segment 342 that is sealed and slidably connected with the second cylindrical chamber 351, the valve core 34 is connected with the bottom of the second cylindrical chamber 351 through a connection spring 36, and the valve core 34 is used When moving toward the second liquid inlet port 32, the volume of the part where the second liquid infusion channel 33 communicates with the second liquid outlet port 31 becomes smaller to generate a flow to the second liquid outlet port 31. The positive pressure of the infusion set prevents blood backflow when the connector of the infusion set is pulled out from the second liquid inlet port 32 after the infusion is completed.

In this embodiment, in order to facilitate the manufacture of the positive pressure joint 3, the positive pressure joint 3 adopts a two-piece structure, specifically, the positive pressure joint 3 includes a second male joint 301 and a The joint 301 is fixedly connected to the second female joint 302, the second male joint 301 includes a second male joint main body 301a, the second liquid outlet 31 located at one end of the second male joint main body 301a, the second liquid outlet end located at the The second plug-in end 301b at the other end of the second male connector body 301a, and the second male connector cavity 301c disposed through the second liquid outlet end 31, the second female connector 302 includes a second female connector body 302a, the second liquid inlet 32 at one end of the second female connector body 302a, the second socket end 302b at the other end of the second female connector body 302a, and the second inlet The liquid end 32 and the second female joint inner cavity 302c of the second socket end 302b, the second female joint inner cavity 302c includes the first cylindrical cavity 331, and passes through the second socket end 302b The installed installation cavity 302d (the installation cavity 302d and the second male connector inner cavity 301c constitute the communication cavity 332), the core seat 35 is integrated with the second insertion end 301b of the second male connector 301 molding, the second insertion end 301b of the second male connector 301 is socketed from the second socket end 302b of the second female connector 302 into the installation cavity 302d, and the second male connector 301 and the The second female joint 302 adopts a snap-fit structure (not labeled) and a sealing ring (not labeled) to achieve a fixed and sealed connection. The core base 35 is accommodated in the installation cavity 302d, and the inside of the core base 35 is provided with a communication hole 352 connecting the second male connector inner cavity 301c with the installation cavity 302d.

In addition, the second liquid inlet 32 is installed with a second elastic sealing plug 37 , and the second elastic sealing plug 37 is facing from the end of the second elastic sealing plug 37 facing the second liquid inlet 32 . A second slit 371 is provided on the end face of the second liquid inlet end 32, and the second slit 371 has a closed state of being squeezed and closed by the main body of the second elastic sealing plug 37 (as shown in FIG. 4), and a stretched state (not shown) for the connector of the infusion set to squeeze through and communicate with the second liquid outlet 31.

Before the connector of the infusion set is inserted into the second liquid inlet 32, the second elastic sealing plug 37 is in a closed state to seal the second liquid inlet 32, and bacteria and dust cannot pass through the second liquid inlet. The liquid end 32 enters, and when the connector of the infusion set is inserted into the second liquid inlet end 32, the second elastic sealing plug 37 is engaged with the joint of the infusion set. The second liquid inlet end 32 enters, and the bite of the second elastic sealing plug 37 on the joint of the infusion set produces a grip force, thus, the joint of the infusion set starts from the second liquid inlet end 32 In the process of pulling out, the connector of the infusion set is not easy to be pushed up by the valve core 34 and directly ejected, resulting in the remaining medicinal liquid being splashed and wasted.

The above are only preferred embodiments of the present utility model, and are not intended to limit the scope of patents. Any equivalent structure or equivalent process transformation made by using the description of the utility model and the accompanying drawings is directly or indirectly used in other related technical fields. All are included in the scope of patent protection of the utility model in the same way.

Claims (9)

1. a closed positive pressure remaining needle, it is characterized in that, described closed positive pressure remaining needle comprises syringe needle, positive pressure connector, closed joint, and connecting line, described closed joint comprises the first liquid outlet be connected with described connecting line, in order to the first liquid feeding end be connected with the joint of transfusion device, first infusion channel of through described first liquid feeding end and described first liquid outlet, and the first elastic packing plug be located in described first infusion channel, one first slit is offered to the end face back to described first liquid feeding end of described first elastic packing plug from the end face in the face of described first liquid feeding end of described first elastic packing plug, described first slit has the closed closure state by the extruding of the main body of described first elastic packing plug, and the softened state got into through with the joint for described transfusion device and be communicated with described first liquid outlet.

2. closed positive pressure remaining needle as claimed in claim 1, it is characterized in that, the first female joint that described closed joint comprises the first male joint and is fixedly connected with described first male joint, described first male joint comprises the first male joint main body, be positioned at described first liquid outlet of one end of described first male joint main body, be positioned at the first inserted terminal of the other end of described first male joint main body, and the first male joint inner chamber of through described first liquid outlet and described first inserted terminal, described first female joint comprises the first female joint main body, be positioned at described first liquid feeding end of one end of described first female joint main body, be positioned at the first socket end of the other end of described first female joint main body, and the first female joint inner chamber of through described first liquid feeding end and described first socket end, first inserted terminal of described first male joint is socketed with described first female joint inner chamber from the first socket end of described first female joint, described first elastic packing plug is installed in described first female joint inner chamber, and the end face of the first inserted terminal of the end face back to described first liquid feeding end of described first elastic packing plug and described first male joint abuts against.

3. closed positive pressure remaining needle as claimed in claim 2, is characterized in that, described first male joint adopts ultrasonic bonding with described first female joint and is fixedly connected with.

4. closed positive pressure remaining needle as claimed in claim 2, it is characterized in that, the end face of the first inserted terminal of described first male joint is convexly equipped with annular stop portion around the port of described first male joint inner chamber, the inner side in described annular stop portion is formed with spacing space, and one end away from described first liquid feeding end of described first elastic packing plug is accommodating and be limited in described spacing space.

5. closed positive pressure remaining needle as claimed in claim 1, it is characterized in that, the single channel pipe that described connecting line comprises tee T, is connected with described syringe needle by the Single port of described tee T, the other two-port of described tee T is connected with described positive pressure connector and described closed joint.

6. closed positive pressure remaining needle as claimed in claim 1, it is characterized in that, described positive pressure connector comprises the second liquid outlet be connected with described connecting line, in order to the second liquid feeding end be connected with the joint of transfusion device, the second infusion channel that through described second liquid outlet and described second liquid feeding end are arranged, be located at the spool in described second infusion channel and core print seat, described second infusion channel comprises the first cylinder chamber that through described second liquid feeding end is arranged, and the first connected chamber that through described second liquid outlet is arranged, described core print seat is located in described first connected chamber, described core print seat has just to the second cylinder chamber that described first cylinder chamber is arranged, seal and the first paragraph be slidably connected with described first cylinder chamber, and seal and the second segment be slidably connected with described second cylinder chamber, described spool is connected by linking springs with the bottom of described second cylinder chamber, described spool is in order to when moving to described second liquid feeding end direction, the volume of the part that described second infusion channel is communicated with described second liquid outlet diminishes and produces the positive pressure to described second liquid outlet.

7. closed positive pressure remaining needle as claimed in claim 6, it is characterized in that, the second female joint that described positive pressure connector comprises the second male joint and is fixedly connected with described second male joint, described second male joint comprises the second male joint main body, be positioned at described second liquid outlet of one end of described second male joint main body, be positioned at the second inserted terminal of the other end of described second male joint main body, and the second male joint inner chamber that through described second liquid outlet is arranged, described second female joint comprises the second female joint main body, be positioned at described second liquid feeding end of one end of described second female joint main body, be positioned at the second socket end of the other end of described second female joint main body, and the second female joint inner chamber of through described second liquid feeding end and described second socket end, described second female joint inner chamber comprises described first cylinder chamber, and the installation cavity that through described second socket end is arranged, second inserted terminal of described core print seat and described second male joint is one-body molded, second inserted terminal of described second male joint is socketed with described installation from the second socket end of described second female joint, and described core print seat is placed in described installation cavity, the inside of described core print seat offers the intercommunicating pore be communicated with described installation cavity by described second male joint inner chamber.

8. closed positive pressure remaining needle as claimed in claim 7, it is characterized in that, described second liquid feeding end is provided with the second elastic packing plug, one second slit is offered to the end face back to described second liquid feeding end of described second elastic packing plug, the softened state that described second slit has by the extruding of the main body of described second elastic packing plug closed closure state and gets into through with the joint for described transfusion device and be communicated with described second liquid outlet from the end face in the face of described second liquid feeding end of described second elastic packing plug.

9. closed positive pressure remaining needle as claimed in claim 7, is characterized in that, described second male joint and described second female joint adopt fastening structure and sealing ring and realize fixing and be tightly connected.